fix(tui): update picker_test for switchProviderModel 4-value return

#568 added a bool return to switchProviderModel (model, string, bool,
tea.Cmd) and updated every call site except picker_test.go:771, which
still assigned three values. That broke the internal/tui test build
and turned Smoke red on main. Add the missing receiver here.

.gitignore

@@ -27,6 +27,10 @@ report.[0-9]_.[0-9]_.[0-9]_.[0-9]_.json
 .cache
 *.tsbuildinfo
 
+# Go build/module caches (GOCACHE/GOMODCACHE pointed here for local runs)
+.gocache/
+.gomodcache/
+
 # IntelliJ based IDEs
 .idea
 
@@ -37,7 +41,10 @@ report.[0-9]_.[0-9]_.[0-9]_.[0-9]_.json
 
 /zero
 /zero.exe
+/zero-windows-command-runner.exe
+/zero-windows-sandbox-setup.exe
 /zero-skills
+/.zero-binary-version
 /snake-game.html
 
 # Superpowers skill artifacts (brainstorm mockups, specs, plans) — local only
@@ -47,3 +54,4 @@ docs/superpowers/
 # Termux/Android build artifacts
 zero-termux-arm64
 zero-linux-sandbox
+zero-seccomp

.release-please-manifest.json

@@ -1 +1 @@
-{".":"0.1.0"}
+{".":"0.2.0"}

AGENTS.md

@@ -132,7 +132,7 @@ description: Run the project's benchmark suite and summarize the deltas.
 3. Report any regression > 5% with the function name and the previous value.
 ```
 
-Only `name` and `description` are recognized in the frontmatter today. The `name` defaults to the directory name. If two skills declare the same name, the one in the lexicographically-first directory wins — duplicates are dropped silently. Plugin-declared skills (section 6) are not yet merged into the loader, so a `skills:` entry inside a plugin's `plugin.json` is not visible to the `skill` tool today.
+Only `name` and `description` are recognized in the frontmatter today. The `name` defaults to the directory name. Within a single skills root, duplicate names are resolved by lexicographic directory order. During an agent run, Zero loads the default skills directory before plugin skill roots; earlier roots win name collisions silently. Plugin-declared skills (section 6) are merged into the active agent run at plugin activation time, so bundled skills appear in the available skills list and can be loaded with the `skill` tool.
 
 The `skill` core tool lets the agent load any discovered skill by name.
 
@@ -282,7 +282,7 @@ A plugin is enabled by being present in the plugins directory and disabled by re
 
 Plugin commands run with the plugin directory as their working directory. Use relative paths; the loader resolves them at activation time.
 
-> **Roadmap.** An in-UI plugins manager (browse, install, enable / disable) is on the backlog. Today you use the `zero plugins` CLI subcommands above. Skills declared inside a plugin's `plugin.json` are not yet merged into the `skill` tool's discovery (see section 3).
+> **Roadmap.** An in-UI plugins manager (browse, install, enable / disable) is on the backlog. Today you use the `zero plugins` CLI subcommands above.
 
 ## 7. Configuration locations
 

CHANGELOG.md

@@ -6,6 +6,71 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 aims to follow [Semantic Versioning](https://semver.org/spec/v2.0.0.html) once the first release is
 tagged. Until then, source builds report the version `dev`.
 
+## [0.2.0](https://github.com/Gitlawb/zero/compare/v0.1.0...v0.2.0) (2026-07-06)
+
+
+### Features
+
+* add --auto flag for LLM-generated commit messages ([#423](https://github.com/Gitlawb/zero/issues/423)) ([b0abde7](https://github.com/Gitlawb/zero/commit/b0abde7d0697e808480cd59d69a6f4d0c6320475))
+* add zero changes push and pr subcommands, and extra repo-info metrics ([#391](https://github.com/Gitlawb/zero/issues/391)) ([2312abe](https://github.com/Gitlawb/zero/commit/2312abe5ddd95f4c6ef373cfb61cc03092f48cdd))
+* agent quality, caching, retry, and tooling upgrades ([#506](https://github.com/Gitlawb/zero/issues/506)) ([3c81fea](https://github.com/Gitlawb/zero/commit/3c81fea22873ee3df7fc97b10cb4f77792706c4b))
+* **agent:** curb over-engineering the solution in the editing discipline ([#517](https://github.com/Gitlawb/zero/issues/517)) ([f4c998a](https://github.com/Gitlawb/zero/commit/f4c998ac30c4f07ff313a2d706791e857293be49)), closes [#516](https://github.com/Gitlawb/zero/issues/516)
+* **agent:** inject per-user config.UserConfigDir()/zero/ZERO.md guidelines into system prompt ([#475](https://github.com/Gitlawb/zero/issues/475)) ([7b10aab](https://github.com/Gitlawb/zero/commit/7b10aab74bf14a01166b2cea22deab79bba9850b))
+* **openai:** forward prompt_cache_key for server-side prefix cache routing ([#515](https://github.com/Gitlawb/zero/issues/515)) ([87e7e69](https://github.com/Gitlawb/zero/commit/87e7e69afd18b5539579856f3a61c6a95bc445ae))
+* **providers:** add `zero providers models` to discover a provider's models ([#386](https://github.com/Gitlawb/zero/issues/386)) ([0bc8074](https://github.com/Gitlawb/zero/commit/0bc8074c97b0310e4a9d70c3f967003ee5e8a59f))
+* **providers:** add KiloCode and OpenCode provider support ([#388](https://github.com/Gitlawb/zero/issues/388)) ([b1ccb6d](https://github.com/Gitlawb/zero/commit/b1ccb6d9c1875377f5e5ea81a1304edd1e41ab4f))
+* **providers:** add Meituan LongCat catalog preset ([#424](https://github.com/Gitlawb/zero/issues/424)) ([b4275e3](https://github.com/Gitlawb/zero/commit/b4275e350472b2490212bf814709819d354c1216))
+* **providers:** split minimax zai into intl cn ([#398](https://github.com/Gitlawb/zero/issues/398)) ([aaad4d2](https://github.com/Gitlawb/zero/commit/aaad4d271270f41af837b6f3b60ae80beba0c645))
+* require manual approval before npm publish + drop release-as pin ([#369](https://github.com/Gitlawb/zero/issues/369)) ([bd89a1f](https://github.com/Gitlawb/zero/commit/bd89a1f451643c1b65ec803070abc7b116631ebe))
+* **sandbox:** unelevated Windows fallback tier instead of prompts-only degrade ([#427](https://github.com/Gitlawb/zero/issues/427)) ([b9ddd6f](https://github.com/Gitlawb/zero/commit/b9ddd6f42138312a1fee8d8bb67c46c8eb1dea2f))
+* support shift enter for composer newlines ([#462](https://github.com/Gitlawb/zero/issues/462)) ([daf65e0](https://github.com/Gitlawb/zero/commit/daf65e0af9a040314d4ab337b0ad59c55416b7bc))
+* **tui:** /loop — repeat a prompt or command on an interval or self-paced ([#502](https://github.com/Gitlawb/zero/issues/502)) ([387fe67](https://github.com/Gitlawb/zero/commit/387fe67ee7cd81317c9c969f5906a4437080fea3))
+* **tui:** add search/filter to provider picker in setup wizard ([#400](https://github.com/Gitlawb/zero/issues/400)) ([2fcea71](https://github.com/Gitlawb/zero/commit/2fcea71778d23e050c93409c471aef45b68c1621))
+* **update:** add zero upgrade command to apply self-updates ([#461](https://github.com/Gitlawb/zero/issues/461)) ([5f36349](https://github.com/Gitlawb/zero/commit/5f36349c1884e81fa9bc66bb5fe813b627e897b7))
+
+
+### Bug Fixes
+
+* **action:** keep provider key scoped to zero step ([#448](https://github.com/Gitlawb/zero/issues/448)) ([407a927](https://github.com/Gitlawb/zero/commit/407a92739ff508cba32d2c12b3f36f0efcdd54c3))
+* add android platform support for Termux npm install ([#455](https://github.com/Gitlawb/zero/issues/455)) ([9bd93c6](https://github.com/Gitlawb/zero/commit/9bd93c62f8d57fb74057284aa66a1b6e1429dcdd)), closes [#449](https://github.com/Gitlawb/zero/issues/449)
+* **agent:** reject a malformed additional_permissions payload before prompting ([#453](https://github.com/Gitlawb/zero/issues/453)) ([e4f760e](https://github.com/Gitlawb/zero/commit/e4f760ee8bd57299cd2fcb37e8e23130037c2607))
+* allow non-TLS connections to private-network provider endpoints ([#444](https://github.com/Gitlawb/zero/issues/444)) ([1d86384](https://github.com/Gitlawb/zero/commit/1d8638466ca31517eb9db2b9353d3dce1cbeeabc))
+* **auth:** route zero auth login chatgpt to the dedicated ChatGPT flow ([#443](https://github.com/Gitlawb/zero/issues/443)) ([305a62c](https://github.com/Gitlawb/zero/commit/305a62c954ca6cec00bc58d5398f933415156aff))
+* **config:** fall back to a usable saved provider instead of forcing full re-onboarding ([#410](https://github.com/Gitlawb/zero/issues/410)) ([c60ad87](https://github.com/Gitlawb/zero/commit/c60ad8729f79bb841114d352ee2d2fe29d5d0e41))
+* **config:** let a gateway ANTHROPIC_BASE_URL resolve as anthropic-compatible ([#497](https://github.com/Gitlawb/zero/issues/497)) ([30dd7c3](https://github.com/Gitlawb/zero/commit/30dd7c3112ad22d42fa12b5addd4e38f4beda42a)), closes [#479](https://github.com/Gitlawb/zero/issues/479)
+* **config:** unbrick first-run setup — default google/anthropic models, enter setup on fixable config errors ([#385](https://github.com/Gitlawb/zero/issues/385)) ([72eed06](https://github.com/Gitlawb/zero/commit/72eed06b4f94c43d75d31fe54a58d2f566de059e))
+* **config:** use ~/.config on macOS and enter setup when no provider ([#371](https://github.com/Gitlawb/zero/issues/371)) ([#372](https://github.com/Gitlawb/zero/issues/372)) ([027a8f2](https://github.com/Gitlawb/zero/commit/027a8f2768b17b89f5c8270887f156e2ccda69ea))
+* **docs:** rename AGENTS.MD > AGENTS.md ([#438](https://github.com/Gitlawb/zero/issues/438)) ([4266baf](https://github.com/Gitlawb/zero/commit/4266baf222df583ed2078b776687f12d496475b5))
+* **gemini:** strip unsupported JSON Schema fields from tool declarations ([#374](https://github.com/Gitlawb/zero/issues/374)) ([39e7100](https://github.com/Gitlawb/zero/commit/39e7100674150144a1152e3110c64c7cf0321d64)), closes [#373](https://github.com/Gitlawb/zero/issues/373)
+* **install:** persist install dir to user PATH on Windows ([#407](https://github.com/Gitlawb/zero/issues/407)) ([bdb1b0e](https://github.com/Gitlawb/zero/commit/bdb1b0ecd15859b1712a6037d296dace7f9c3c3f))
+* **mcp:** block cross-origin credential redirects ([#396](https://github.com/Gitlawb/zero/issues/396)) ([f915f70](https://github.com/Gitlawb/zero/commit/f915f70e5a3096e2419fa8d961a0f84a626fa4a9))
+* **oauth:** treat Windows ERROR_ACCESS_DENIED as lock contention in createSecretFile ([#445](https://github.com/Gitlawb/zero/issues/445)) ([d05e914](https://github.com/Gitlawb/zero/commit/d05e9148a7f79f67d1d3c31fca2775f21fbd331e))
+* **openai:** handle Ollama reasoning stream deltas ([#486](https://github.com/Gitlawb/zero/issues/486)) ([f6c0606](https://github.com/Gitlawb/zero/commit/f6c060631e18e082dda24cc4dc0903c31c2120d6))
+* preserve conversation context in exec prompts ([#460](https://github.com/Gitlawb/zero/issues/460)) ([949ee43](https://github.com/Gitlawb/zero/commit/949ee43f71e5cb7fab4695c5cb7b442fe4ecfbf7))
+* **provider-wizard:** allow multiple custom OpenAI-compatible providers ([#403](https://github.com/Gitlawb/zero/issues/403)) ([3fbbd28](https://github.com/Gitlawb/zero/commit/3fbbd28e4c586822cc4312c86232d94befe56e87))
+* **sandbox:** fix nested pipe creation under the Windows restricted token ([#456](https://github.com/Gitlawb/zero/issues/456)) ([563a6db](https://github.com/Gitlawb/zero/commit/563a6dbe91e65d5daeefd7626e8a77e30a6d8fb2))
+* **sandbox:** gate /tmp test assertions on GOOS, not path existence ([#426](https://github.com/Gitlawb/zero/issues/426)) ([f653dca](https://github.com/Gitlawb/zero/commit/f653dcac363fb69ad7be5b35e6e0fa6d2bce476d))
+* **sandbox:** self-heal a corrupt unelevated setup marker ([#437](https://github.com/Gitlawb/zero/issues/437)) ([8d0c5fe](https://github.com/Gitlawb/zero/commit/8d0c5feccb8bdbfb015df0508aa6e3bcbd1fd0e8))
+* **specialist:** cap max specialist nesting depth ([#491](https://github.com/Gitlawb/zero/issues/491)) ([177442c](https://github.com/Gitlawb/zero/commit/177442cfe4015bd8df04cc9894f98b468ee796d4))
+* Termux/Android support — PRoot scroll, SIGSYS sandbox, build docs ([#509](https://github.com/Gitlawb/zero/issues/509)) ([0f69d99](https://github.com/Gitlawb/zero/commit/0f69d995e9b586b774f66c066b21abab5e03024a))
+* **tools:** Block MSYS coreutils under Windows sandbox ([#476](https://github.com/Gitlawb/zero/issues/476)) ([81aad58](https://github.com/Gitlawb/zero/commit/81aad58d97839e51c068e2f08907618991fdc3fb))
+* **tools:** CRLF line ending mismatch in edit_file tool on Windows ([#378](https://github.com/Gitlawb/zero/issues/378)) ([33dc7ae](https://github.com/Gitlawb/zero/commit/33dc7ae2cc82c5389675531e1416856dae7151ce))
+* **tools:** fix cmd.exe /S/C corrupting commands with embedded quotes ([#465](https://github.com/Gitlawb/zero/issues/465)) ([190241b](https://github.com/Gitlawb/zero/commit/190241bd593f43211b766e0b13c8e89802d4bb37))
+* **tools:** flag piped POSIX utilities before running on Windows ([#412](https://github.com/Gitlawb/zero/issues/412)) ([5658a36](https://github.com/Gitlawb/zero/commit/5658a366274fc59a9d5336b06a21019c9c25cbf1))
+* **tools:** make grep and glob respect run cancellation ([#464](https://github.com/Gitlawb/zero/issues/464)) ([ba6c026](https://github.com/Gitlawb/zero/commit/ba6c0264697b7d7ed479f6e782fba9700a481e3d))
+* **tools:** require permission before web_search requests ([#382](https://github.com/Gitlawb/zero/issues/382)) ([960db96](https://github.com/Gitlawb/zero/commit/960db9660e4e31dc588fe8f7d6f116ff5e225566))
+* **tui:** compose help overlay through the viewport overlay pipeline ([#421](https://github.com/Gitlawb/zero/issues/421)) ([5b2b4de](https://github.com/Gitlawb/zero/commit/5b2b4dea1aaf9e0f68baa25e97e83296fb17b1a2))
+* **tui:** keep the profile name on /model switch so the stored key resolves ([#441](https://github.com/Gitlawb/zero/issues/441)) ([9134148](https://github.com/Gitlawb/zero/commit/9134148f4df3e4e556fba6c2f8babfdf6fcfeee1)), closes [#440](https://github.com/Gitlawb/zero/issues/440)
+* **tui:** resolve every permission request so the agent can't deadlock ([#397](https://github.com/Gitlawb/zero/issues/397)) ([952788f](https://github.com/Gitlawb/zero/commit/952788f72d32957659fe004521fcc8372b9ba9b4))
+* **tui:** show an M suffix for million-scale token counts ([#457](https://github.com/Gitlawb/zero/issues/457)) ([0562e3b](https://github.com/Gitlawb/zero/commit/0562e3bef7df2328610a48a1e81632a8da4aec64))
+* **tui:** title /model rows by model name, not the catalog description ([#395](https://github.com/Gitlawb/zero/issues/395)) ([cdf9d83](https://github.com/Gitlawb/zero/commit/cdf9d839ae57a729f292f36f7c5b0c67b41b288d))
+
+
+### Performance Improvements
+
+* cache TUI model registry ([#496](https://github.com/Gitlawb/zero/issues/496)) ([e7d88b4](https://github.com/Gitlawb/zero/commit/e7d88b4b518049733da25a8447c00144bd1da518))
+* universal tool-output ceiling with spill + async post-edit diagnostics ([#518](https://github.com/Gitlawb/zero/issues/518)) ([95ccd5b](https://github.com/Gitlawb/zero/commit/95ccd5bc327f6fb464ff0239f7229de789f578dc))
+
 ## 0.1.0 (2026-07-02)
 
 

go.mod

@@ -1,8 +1,6 @@
 module github.com/Gitlawb/zero
 
-go 1.25.0
-
-toolchain go1.26.4
+go 1.26.4
 
 require (
 	charm.land/bubbles/v2 v2.1.0
@@ -14,6 +12,7 @@ require (
 	github.com/charmbracelet/colorprofile v0.4.3
 	github.com/charmbracelet/x/ansi v0.11.7
 	github.com/charmbracelet/x/term v0.2.2
+	github.com/coder/websocket v1.8.15
 	github.com/ledongthuc/pdf v0.0.0-20250511090121-5959a4027728
 	golang.org/x/sys v0.46.0
 	mvdan.cc/sh/v3 v3.13.1

go.sum

@@ -32,6 +32,8 @@ github.com/clipperhouse/displaywidth v0.11.0 h1:lBc6kY44VFw+TDx4I8opi/EtL9m20WSE
 github.com/clipperhouse/displaywidth v0.11.0/go.mod h1:bkrFNkf81G8HyVqmKGxsPufD3JhNl3dSqnGhOoSD/o0=
 github.com/clipperhouse/uax29/v2 v2.7.0 h1:+gs4oBZ2gPfVrKPthwbMzWZDaAFPGYK72F0NJv2v7Vk=
 github.com/clipperhouse/uax29/v2 v2.7.0/go.mod h1:EFJ2TJMRUaplDxHKj1qAEhCtQPW2tJSwu5BF98AuoVM=
+github.com/coder/websocket v1.8.15 h1:6B2JPeOGlpff2Uz6vOEH1Vzpi0iUz20A+lPVhPHtNUA=
+github.com/coder/websocket v1.8.15/go.mod h1:NX3SzP+inril6yawo5CQXx8+fk145lPDC6pumgx0mVg=
 github.com/dlclark/regexp2/v2 v2.2.1 h1:mf4KkFUj0gJuarK8P+LgiS+Lit7m9N1yAwEfPbee7R0=
 github.com/dlclark/regexp2/v2 v2.2.1/go.mod h1:avUrQvPaLz2DrFNHJF0taWAFFX2C1GMSSoeiqFjcBmU=
 github.com/go-quicktest/qt v1.102.0 h1:HSQxCeh5YZH3EL3W39ixjtyaEhcWSXQHtHnMBzSs474=

internal/acp/agent.go

@@ -5,6 +5,7 @@ import (
 	"encoding/base64"
 	"encoding/json"
 	"errors"
+	"log"
 	"strings"
 	"sync"
 
@@ -159,8 +160,14 @@ func (a *Agent) handleSessionLoad(_ context.Context, params json.RawMessage) (an
 	// Load history BEFORE publishing the session so no concurrent prompt observes
 	// a half-initialized session (registerSession sets history under the lock and
 	// reuses an already-live session rather than orphaning its in-flight turn).
-	history := a.loadHistory(meta.SessionID)
+	history, historyErr := a.loadHistory(meta.SessionID)
 	sess := a.registerSession(meta.SessionID, root, history)
+	a.warnPersistence(
+		&notifier{conn: a.conn, sessionID: sess.id},
+		"load session history",
+		"Could not load session history. The session is open, but earlier turns may be missing until storage recovers.",
+		historyErr,
+	)
 	return LoadSessionResult{
 		Modes: a.modeState(sess),
 	}, nil
@@ -253,7 +260,14 @@ func (a *Agent) runTurn(ctx context.Context, sess *acpSession, userText string,
 	if stopErr != nil {
 		return "", RPCError(codeInternalError, stopErr.Error())
 	}
-	a.persistTurn(sess, userText, result.FinalAnswer)
+	if err := a.persistTurn(sess, userText, result.FinalAnswer); err != nil {
+		a.warnPersistence(
+			note,
+			"save session history",
+			"Could not save session history. This turn is available in memory, but future resume may miss it until storage recovers.",
+			err,
+		)
+	}
 	return reason, nil
 }
 
@@ -386,29 +400,34 @@ func (a *Agent) modeState(s *acpSession) *SessionModeState {
 
 // ---- persistence + continuity ----
 
-func (a *Agent) persistTurn(sess *acpSession, user, assistant string) {
-	if a.deps.Store != nil {
-		_, _ = a.deps.Store.AppendEvent(sess.id, sessions.AppendEventInput{
-			Type:    sessions.EventMessage,
-			Payload: map[string]any{"role": "user", "content": user},
-		})
-		if assistant != "" {
-			_, _ = a.deps.Store.AppendEvent(sess.id, sessions.AppendEventInput{
-				Type:    sessions.EventMessage,
-				Payload: map[string]any{"role": "assistant", "content": assistant},
-			})
-		}
-	}
-	sess.appendHistory(turnRecord{user: user, assistant: assistant})
-}
-
-func (a *Agent) loadHistory(sessionID string) []turnRecord {
+func (a *Agent) persistTurn(sess *acpSession, user, assistant string) error {
+	defer sess.appendHistory(turnRecord{user: user, assistant: assistant})
 	if a.deps.Store == nil {
 		return nil
 	}
+	events := []sessions.AppendEventInput{
+		{
+			Type:    sessions.EventMessage,
+			Payload: map[string]any{"role": "user", "content": user},
+		},
+	}
+	if assistant != "" {
+		events = append(events, sessions.AppendEventInput{
+			Type:    sessions.EventMessage,
+			Payload: map[string]any{"role": "assistant", "content": assistant},
+		})
+	}
+	_, err := a.deps.Store.AppendEvents(sess.id, events)
+	return err
+}
+
+func (a *Agent) loadHistory(sessionID string) ([]turnRecord, error) {
+	if a.deps.Store == nil {
+		return nil, nil
+	}
 	events, err := a.deps.Store.ReadEvents(sessionID)
 	if err != nil {
-		return nil
+		return nil, err
 	}
 	var records []turnRecord
 	var pendingUser string
@@ -444,7 +463,21 @@ func (a *Agent) loadHistory(sessionID string) []turnRecord {
 	if havePending {
 		records = append(records, turnRecord{user: pendingUser})
 	}
-	return records
+	return records, nil
+}
+
+func (a *Agent) warnPersistence(note *notifier, action string, message string, err error) {
+	if err == nil {
+		return
+	}
+	sessionID := ""
+	if note != nil {
+		sessionID = note.sessionID
+	}
+	log.Printf("zero acp: failed to %s for session %s: %v", action, sessionID, err)
+	if note != nil {
+		note.text("\n\n[zero warning] " + message + "\n")
+	}
 }
 
 // buildPrompt prepends prior conversation as context, since agent.Run drives a

internal/acp/agent_test.go

@@ -5,6 +5,8 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"os"
+	"path/filepath"
 	"strings"
 	"testing"
 	"time"
@@ -242,8 +244,77 @@ func TestACPRejectsInvalidCwd(t *testing.T) {
 	}
 }
 
+func TestACPPromptWarnsWhenTurnPersistenceFails(t *testing.T) {
+	deps := testDeps(t)
+	h := newHarness(t, deps)
+	defer h.stop()
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	var newRes NewSessionResult
+	if err := h.client.Call(ctx, MethodSessionNew, NewSessionParams{Cwd: t.TempDir(), McpServers: []McpServer{}}, &newRes); err != nil {
+		t.Fatalf("session/new: %v", err)
+	}
+	metadataPath := filepath.Join(deps.Store.RootDir, newRes.SessionID, sessions.MetadataFile)
+	if err := os.Remove(metadataPath); err != nil {
+		t.Fatalf("remove metadata: %v", err)
+	}
+
+	var promptRes PromptResult
+	if err := h.client.Call(ctx, MethodSessionPrompt, PromptParams{
+		SessionID: newRes.SessionID,
+		Prompt:    []ContentBlock{TextBlock("hi")},
+	}, &promptRes); err != nil {
+		t.Fatalf("session/prompt: %v", err)
+	}
+	if promptRes.StopReason != StopEndTurn {
+		t.Fatalf("stopReason = %q, want %q", promptRes.StopReason, StopEndTurn)
+	}
+	got := drainTextUntil(t, h.updates, func(text string) bool {
+		return strings.Contains(text, "Hello from ZERO") &&
+			strings.Contains(text, "Could not save session history")
+	})
+	if !strings.Contains(got, "Could not save session history") {
+		t.Fatalf("streamed text = %q, want persistence warning", got)
+	}
+}
+
+func TestACPLoadWarnsWhenHistoryReadFails(t *testing.T) {
+	deps := testDeps(t)
+	cwd := t.TempDir()
+	meta, err := deps.Store.Create(sessions.CreateInput{Title: "ACP session", Cwd: cwd})
+	if err != nil {
+		t.Fatalf("create session: %v", err)
+	}
+	eventsPath := filepath.Join(deps.Store.RootDir, meta.SessionID, sessions.EventsFile)
+	if err := os.WriteFile(eventsPath, []byte("{bad json}\n"), 0o600); err != nil {
+		t.Fatalf("write corrupt events: %v", err)
+	}
+	h := newHarness(t, deps)
+	defer h.stop()
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	if err := h.client.Call(ctx, MethodSessionLoad, LoadSessionParams{SessionID: meta.SessionID, Cwd: cwd, McpServers: []McpServer{}}, &LoadSessionResult{}); err != nil {
+		t.Fatalf("session/load: %v", err)
+	}
+	got := drainTextUntil(t, h.updates, func(text string) bool {
+		return strings.Contains(text, "Could not load session history")
+	})
+	if !strings.Contains(got, "Could not load session history") {
+		t.Fatalf("streamed text = %q, want load warning", got)
+	}
+}
+
 // drainText collects streamed chunks for a short window and concatenates them.
 func drainText(t *testing.T, ch <-chan string) string {
+	t.Helper()
+	return drainTextUntil(t, ch, func(text string) bool {
+		return strings.Contains(text, "Hello from ZERO")
+	})
+}
+
+func drainTextUntil(t *testing.T, ch <-chan string, done func(string) bool) string {
 	t.Helper()
 	var b strings.Builder
 	deadline := time.After(2 * time.Second)
@@ -251,7 +322,7 @@ func drainText(t *testing.T, ch <-chan string) string {
 		select {
 		case s := <-ch:
 			b.WriteString(s)
-			if strings.Contains(b.String(), "Hello from ZERO") {
+			if done(b.String()) {
 				return b.String()
 			}
 		case <-deadline:

internal/agent/loop.go

@@ -109,7 +109,7 @@ const escalationFailedNoticePrefix = "Note: could not switch to the requested mo
 // The system prompt (core coding-craft instructions + workspace context + safety
 // confirmation policy) is assembled in system_prompt.go via buildSystemPrompt.
 
-func Run(ctx context.Context, prompt string, provider Provider, options Options) (Result, error) {
+func Run(ctx context.Context, prompt string, provider Provider, options Options) (result Result, err error) {
 	if provider == nil {
 		return Result{}, errors.New("agent provider is required")
 	}
@@ -161,7 +161,11 @@ func Run(ctx context.Context, prompt string, provider Provider, options Options)
 	// doesn't re-run the recursive schema→map conversion for every tool every turn.
 	toolDefCache := map[string]zeroruntime.ToolDefinition{}
 
-	result := Result{Messages: copyMessages(messages)}
+	result = Result{Messages: copyMessages(messages)}
+	dispatchSessionStart(ctx, options)
+	defer func() {
+		dispatchSessionEnd(ctx, options, result, err)
+	}()
 	for turn := 0; turn < maxTurns; turn++ {
 		result.Turns = turn + 1
 
@@ -721,7 +725,8 @@ func Run(ctx context.Context, prompt string, provider Provider, options Options)
 			Content: nudge,
 		})
 	}
-	if answer, finalMessages, finishReason := finalAnswerAfterMaxTurns(ctx, provider, messages, options); strings.TrimSpace(answer) != "" {
+	finalExposed, _ := partitionToolsCached(registry, permissionMode, options, loaded, toolDefCache)
+	if answer, finalMessages, finishReason := finalAnswerAfterMaxTurns(ctx, provider, messages, finalExposed, options); strings.TrimSpace(answer) != "" {
 		result.FinalAnswer = answer
 		result.FinishReason = finishReason
 		result.Messages = copyMessages(finalMessages)
@@ -741,7 +746,7 @@ func Run(ctx context.Context, prompt string, provider Provider, options Options)
 	return result, nil
 }
 
-func finalAnswerAfterMaxTurns(ctx context.Context, provider Provider, messages []zeroruntime.Message, options Options) (string, []zeroruntime.Message, string) {
+func finalAnswerAfterMaxTurns(ctx context.Context, provider Provider, messages []zeroruntime.Message, toolDefs []zeroruntime.ToolDefinition, options Options) (string, []zeroruntime.Message, string) {
 	finalMessages := copyMessages(messages)
 	finalMessages = append(finalMessages, zeroruntime.Message{
 		Role:    zeroruntime.MessageRoleUser,
@@ -752,6 +757,7 @@ func finalAnswerAfterMaxTurns(ctx context.Context, provider Provider, messages [
 	// transient hiccup doesn't drop the final summary (AUDIT-L1).
 	stream, err := streamWithReconnect(ctx, provider, zeroruntime.CompletionRequest{
 		Messages:        copyMessages(finalMessages),
+		Tools:           toolDefs,
 		ReasoningEffort: options.ReasoningEffort,
 		PromptCacheKey:  options.SessionID,
 	}, reconnectNoticeFor(options))
@@ -1568,6 +1574,54 @@ func dispatchAfterTool(ctx context.Context, options Options, call ToolCall, args
 	return strings.TrimSpace(strings.Join(outcome.Messages, "\n"))
 }
 
+// dispatchSessionStart runs configured sessionStart hooks once before the first
+// model turn. Lifecycle hooks are advisory: dispatcher failures are audited but
+// never block the run.
+func dispatchSessionStart(ctx context.Context, options Options) {
+	if options.Hooks == nil {
+		return
+	}
+	options.Hooks.Dispatch(ctx, hooks.DispatchInput{
+		Event: hooks.EventSessionStart,
+		Payload: map[string]any{
+			"event":        string(hooks.EventSessionStart),
+			"sessionId":    options.SessionID,
+			"cwd":          options.Cwd,
+			"provider":     options.ProviderName,
+			"model":        options.Model,
+			"depth":        options.Depth,
+			"tag":          options.Tag,
+			"sessionTitle": options.SessionTitle,
+		},
+	})
+}
+
+// dispatchSessionEnd runs configured sessionEnd hooks once when the agent run
+// exits, including early error returns. Lifecycle hooks are advisory.
+func dispatchSessionEnd(ctx context.Context, options Options, result Result, runErr error) {
+	if options.Hooks == nil {
+		return
+	}
+	payload := map[string]any{
+		"event":        string(hooks.EventSessionEnd),
+		"sessionId":    options.SessionID,
+		"cwd":          options.Cwd,
+		"provider":     options.ProviderName,
+		"model":        options.Model,
+		"turns":        result.Turns,
+		"stopReason":   string(result.StopReason),
+		"finishReason": result.FinishReason,
+		"incomplete":   result.Incomplete,
+	}
+	if runErr != nil {
+		payload["error"] = runErr.Error()
+	}
+	options.Hooks.Dispatch(ctx, hooks.DispatchInput{
+		Event:   hooks.EventSessionEnd,
+		Payload: payload,
+	})
+}
+
 // blockedByHookResult is the tool result for a call vetoed by a beforeTool hook.
 func blockedByHookResult(call ToolCall, outcome hooks.DispatchOutcome) ToolResult {
 	// The hook reason (its stdout/stderr) is model-visible here, an intercepted

internal/agent/loop_test.go

@@ -11,6 +11,7 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/Gitlawb/zero/internal/hooks"
 	"github.com/Gitlawb/zero/internal/sandbox"
 	"github.com/Gitlawb/zero/internal/specmode"
 	"github.com/Gitlawb/zero/internal/tools"
@@ -38,6 +39,59 @@ func (provider *mockProvider) StreamCompletion(ctx context.Context, request zero
 	return ch, nil
 }
 
+func TestRunDispatchesSessionLifecycleHooks(t *testing.T) {
+	audit, err := hooks.NewAuditStore(hooks.AuditStoreOptions{AuditPath: filepath.Join(t.TempDir(), "audit.jsonl")})
+	if err != nil {
+		t.Fatalf("NewAuditStore: %v", err)
+	}
+	dispatcher := hooks.NewDispatcher(hooks.DispatcherOptions{
+		Config: hooks.Config{
+			Enabled: true,
+			Hooks: []hooks.Definition{
+				{ID: "zero.session-start", Event: hooks.EventSessionStart, Command: "zero-missing-hook-command", Enabled: true},
+				{ID: "zero.session-end", Event: hooks.EventSessionEnd, Command: "zero-missing-hook-command", Enabled: true},
+			},
+		},
+		Audit: audit,
+	})
+	provider := &mockProvider{turns: [][]zeroruntime.StreamEvent{{
+		{Type: zeroruntime.StreamEventText, Content: "done"},
+		{Type: zeroruntime.StreamEventDone},
+	}}}
+
+	_, err = Run(context.Background(), "hi", provider, Options{
+		SessionID:    "session-123",
+		Cwd:          t.TempDir(),
+		ProviderName: "test-provider",
+		Model:        "test-model",
+		Hooks:        dispatcher,
+	})
+	if err != nil {
+		t.Fatalf("Run: %v", err)
+	}
+
+	events, err := audit.ReadEvents()
+	if err != nil {
+		t.Fatalf("ReadEvents: %v", err)
+	}
+	started := map[hooks.Event]int{}
+	completed := map[hooks.Event]int{}
+	for _, event := range events {
+		switch event.Type {
+		case "hook_execution_started":
+			started[event.Event]++
+		case "hook_execution_completed":
+			completed[event.Event]++
+		}
+	}
+	if started[hooks.EventSessionStart] != 1 || completed[hooks.EventSessionStart] != 1 {
+		t.Fatalf("sessionStart audit counts started/completed = %d/%d, events=%#v", started[hooks.EventSessionStart], completed[hooks.EventSessionStart], events)
+	}
+	if started[hooks.EventSessionEnd] != 1 || completed[hooks.EventSessionEnd] != 1 {
+		t.Fatalf("sessionEnd audit counts started/completed = %d/%d, events=%#v", started[hooks.EventSessionEnd], completed[hooks.EventSessionEnd], events)
+	}
+}
+
 type recordingWebSearchTool struct {
 	calls []map[string]any
 }
@@ -2768,11 +2822,11 @@ func TestRunRequestsFinalAnswerAfterMaxTurns(t *testing.T) {
 		t.Fatalf("expected final answer from finalization turn, got %q", result.FinalAnswer)
 	}
 	if len(provider.requests) != 2 {
-		t.Fatalf("expected final no-tools request after max turns, got %d requests", len(provider.requests))
+		t.Fatalf("expected finalization request after max turns, got %d requests", len(provider.requests))
 	}
 	finalRequest := provider.requests[1]
-	if len(finalRequest.Tools) != 0 {
-		t.Fatalf("finalization request must not advertise tools, got %#v", finalRequest.Tools)
+	if toolDefinitionByName(finalRequest.Tools, "read_file") == nil {
+		t.Fatalf("finalization request must keep prior tools exposed for strict provider replay, got %#v", finalRequest.Tools)
 	}
 	lastMessage := finalRequest.Messages[len(finalRequest.Messages)-1]
 	if lastMessage.Role != zeroruntime.MessageRoleUser || !strings.Contains(lastMessage.Content, "tool-turn limit") {

internal/cli/app.go

@@ -686,8 +686,14 @@ func runInteractiveTUIWithSetup(stderr io.Writer, deps appDeps, permissionMode a
 	defer closeMCPRuntime(stderr, mcpRuntime)
 	// A server that could not be reached or validated is skipped, not fatal (one
 	// bad MCP server must not abort startup) — surface each so a missing tool set is
-	// explained rather than silently absent.
+	// explained rather than silently absent. A built-in default the user never
+	// configured (e.g. keyless Firecrawl with no credentials) is the exception: it
+	// was never asked for, so its failure is not worth a startup warning — only
+	// servers the user actually configured warn on failure (issue #552).
 	for _, skipped := range mcpRuntime.Skipped() {
+		if skipped.UnconfiguredDefault {
+			continue
+		}
 		fmt.Fprintf(stderr, "warning: MCP server %s unavailable, skipped: %s\n", skipped.Name, redaction.ErrorMessage(skipped.Err, redaction.Options{}))
 	}
 	// Make local plugins live: register their declared tools into the registry and
@@ -729,8 +735,19 @@ func runInteractiveTUIWithSetup(stderr io.Writer, deps appDeps, permissionMode a
 		Scope:         scope,
 	})
 	lastKnownMCPConfig := mcpConfig
+	sttServerManager := newDictationServerManager(resolved.STT)
+	// Keep STT downloads in the SAME config tree the rest of the TUI uses. Deriving
+	// from userConfigPath (rather than config.UserConfigDir()) matters when the config
+	// root is overridden — e.g. in tests or a custom ZERO config dir — so the two
+	// don't diverge. userConfigPath points at .../zero/config.json, so its dir is the
+	// zero config dir.
+	sttDownloadRoot := ""
+	if userConfigPath != "" {
+		sttDownloadRoot = filepath.Join(filepath.Dir(userConfigPath), "stt")
+	}
 	return deps.runTUI(context.Background(), tui.Options{
 		Cwd:                  workspaceRoot,
+		Version:              version,
 		Theme:                theme,
 		SavedTheme:           resolved.Preferences.Theme,
 		UserConfigPath:       userConfigPath,
@@ -741,6 +758,7 @@ func runInteractiveTUIWithSetup(stderr io.Writer, deps appDeps, permissionMode a
 		ProviderProfile:      resolved.Provider,
 		SavedProviders:       usableSavedProviders(resolved.Providers),
 		FavoriteModels:       resolved.Preferences.FavoriteModels,
+		RecentModels:         resolved.Preferences.RecentModels,
 		RecapsEnabled:        resolved.Preferences.RecapsEnabled(),
 		Provider:             provider,
 		NewProvider:          deps.newProvider,
@@ -791,9 +809,15 @@ func runInteractiveTUIWithSetup(stderr io.Writer, deps appDeps, permissionMode a
 			merged, _ := plugins.MergedSkillsLoaded(deps.skillsDir(), pluginActivation.skillRoots)
 			return merged
 		}),
-		PermissionMode: permissionMode,
-		Notify:         resolved.Notify,
-		KeyBindings:    resolved.KeyBindings,
+		PermissionMode:            permissionMode,
+		Notify:                    resolved.Notify,
+		KeyBindings:               resolved.KeyBindings,
+		STT:                       resolved.STT,
+		BuildDictationTranscriber: newDictationTranscriberFactory(resolved, userConfigPath, sttServerManager),
+		ShutdownDictationServer:   sttServerManager.Shutdown,
+		STTDownloadRoot:           sttDownloadRoot,
+		STTKeyStatus:              newSTTKeyStatus(resolved, userConfigPath),
+		SaveSTTKey:                newSaveSTTKey(userConfigPath),
 		Setup: tui.SetupOptions{
 			Visible:    setupVisible,
 			Required:   needsSetup,

internal/cli/app_test.go

@@ -158,6 +158,86 @@ func TestRunNoArgsLaunchesSetupTUIWithNilProviderWhenNoProviderConfigured(t *tes
 	assertAgentOptions(t, launchedOptions, 12, agent.PermissionModeAsk)
 }
 
+type fakeMCPRuntimeWithSkips struct {
+	skipped []mcp.SkippedServer
+}
+
+func (r fakeMCPRuntimeWithSkips) Close() error { return nil }
+
+func (r fakeMCPRuntimeWithSkips) Skipped() []mcp.SkippedServer { return r.skipped }
+
+func TestTUIStartupSuppressesWarningForUnconfiguredDefaultServer(t *testing.T) {
+	var stdout bytes.Buffer
+	var stderr bytes.Buffer
+	cwd := t.TempDir()
+	setCLIUserConfigRoot(t)
+
+	exitCode := runWithDeps([]string{}, &stdout, &stderr, appDeps{
+		getwd: func() (string, error) {
+			return cwd, nil
+		},
+		resolveConfig: func(workspaceRoot string, overrides config.Overrides) (config.ResolvedConfig, error) {
+			return config.ResolvedConfig{MaxTurns: 8}, nil
+		},
+		resolveMCPConfig: func(workspaceRoot string) (config.MCPConfig, error) {
+			return config.MCPConfig{Servers: map[string]config.MCPServerConfig{
+				"firecrawl": config.DefaultMCPServers()["firecrawl"],
+			}}, nil
+		},
+		registerMCPTools: func(context.Context, *tools.Registry, config.MCPConfig, mcp.RegisterOptions) (mcpToolRuntime, error) {
+			return fakeMCPRuntimeWithSkips{skipped: []mcp.SkippedServer{
+				{Name: "firecrawl", Err: errors.New("returned HTTP 401"), UnconfiguredDefault: true},
+			}}, nil
+		},
+		runTUI: func(ctx context.Context, options tui.Options) int {
+			return 0
+		},
+	})
+
+	if exitCode != 0 {
+		t.Fatalf("exitCode = %d stderr=%s", exitCode, stderr.String())
+	}
+	if strings.Contains(stderr.String(), "firecrawl") {
+		t.Fatalf("stderr = %q, want no warning for an unconfigured default server", stderr.String())
+	}
+}
+
+func TestTUIStartupWarnsForUserConfiguredServerSkip(t *testing.T) {
+	var stdout bytes.Buffer
+	var stderr bytes.Buffer
+	cwd := t.TempDir()
+	setCLIUserConfigRoot(t)
+
+	exitCode := runWithDeps([]string{}, &stdout, &stderr, appDeps{
+		getwd: func() (string, error) {
+			return cwd, nil
+		},
+		resolveConfig: func(workspaceRoot string, overrides config.Overrides) (config.ResolvedConfig, error) {
+			return config.ResolvedConfig{MaxTurns: 8}, nil
+		},
+		resolveMCPConfig: func(workspaceRoot string) (config.MCPConfig, error) {
+			return config.MCPConfig{Servers: map[string]config.MCPServerConfig{
+				"custom": {Type: "stdio", Command: "custom-mcp"},
+			}}, nil
+		},
+		registerMCPTools: func(context.Context, *tools.Registry, config.MCPConfig, mcp.RegisterOptions) (mcpToolRuntime, error) {
+			return fakeMCPRuntimeWithSkips{skipped: []mcp.SkippedServer{
+				{Name: "custom", Err: errors.New("connect failed"), UnconfiguredDefault: false},
+			}}, nil
+		},
+		runTUI: func(ctx context.Context, options tui.Options) int {
+			return 0
+		},
+	})
+
+	if exitCode != 0 {
+		t.Fatalf("exitCode = %d stderr=%s", exitCode, stderr.String())
+	}
+	if !strings.Contains(stderr.String(), "warning: MCP server custom unavailable") {
+		t.Fatalf("stderr = %q, want a warning for a user-configured server that failed", stderr.String())
+	}
+}
+
 func TestRunNoArgsEntersSetupWhenResolveReportsNoActiveProvider(t *testing.T) {
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer

internal/cli/auth.go

@@ -11,10 +11,46 @@ import (
 
 	"github.com/Gitlawb/zero/internal/config"
 	"github.com/Gitlawb/zero/internal/oauth"
+	"github.com/Gitlawb/zero/internal/providercatalog"
 	"github.com/Gitlawb/zero/internal/provideroauth"
 	"github.com/Gitlawb/zero/internal/redaction"
 )
 
+// ensureLoginProviderProfile makes a freshly stored OAuth login visible as a
+// provider: without a profile in config.json the login shows up nowhere — not in
+// `zero providers list`, not in the TUI picker — and `zero providers use <name>`
+// fails "not found", so the user's working active provider looks broken while
+// the new login looks lost. Returns user-facing guidance lines ("" when the
+// login has no catalog entry to scaffold from). Best-effort by design: the
+// token is already stored, so a profile-write failure degrades to a warning
+// line instead of failing a login that succeeded.
+func ensureLoginProviderProfile(deps appDeps, provider string) string {
+	if _, ok := providercatalog.Get(provider); !ok {
+		// Custom OAuth server without a catalog entry — no endpoint/model defaults
+		// to scaffold a profile from; the user wires their own profile.
+		return ""
+	}
+	configPath, err := deps.userConfigPath()
+	if err != nil {
+		return "warning: login saved, but no provider profile was written: " + err.Error()
+	}
+	ensured, err := config.EnsureCatalogProvider(configPath, provider)
+	if err != nil {
+		return "warning: login saved, but no provider profile was written: " + err.Error()
+	}
+	active := strings.EqualFold(strings.TrimSpace(ensured.Active), strings.TrimSpace(ensured.Name))
+	switch {
+	case ensured.Created && active:
+		return fmt.Sprintf("Added provider %q to your config and set it active.", ensured.Name)
+	case ensured.Created:
+		return fmt.Sprintf("Added provider %q to your config; the active provider is still %q.\nSwitch with: zero providers use %s", ensured.Name, ensured.Active, ensured.Name)
+	case active:
+		return fmt.Sprintf("Provider %q is configured and active.", ensured.Name)
+	default:
+		return fmt.Sprintf("Provider %q is already configured.\nSwitch with: zero providers use %s", ensured.Name, ensured.Name)
+	}
+}
+
 // runAuth dispatches `zero auth <command>` for provider OAuth login. It is
 // additive and independent of `zero mcp oauth` (MCP server auth), which is
 // unchanged.
@@ -138,8 +174,10 @@ func runAuthChatGPT(args []string, stdout io.Writer, stderr io.Writer, deps appD
 	if _, err := fmt.Fprint(stdout, statuses); err != nil {
 		return exitCrash
 	}
-	if _, err := fmt.Fprint(stdout, "\nUse it with zero, e.g.:\n  zero --provider chatgpt --model gpt-5.5\n"); err != nil {
-		return exitCrash
+	if line := ensureLoginProviderProfile(deps, "chatgpt"); line != "" {
+		if _, err := fmt.Fprintf(stdout, "\n%s\n", line); err != nil {
+			return exitCrash
+		}
 	}
 	return exitSuccess
 }
@@ -331,6 +369,11 @@ func runAuthLogin(args []string, stdout io.Writer, stderr io.Writer, deps appDep
 	if _, err := fmt.Fprintf(stdout, "Logged in to %s.\n%s\n", parsed.positional[0], oauth.FormatStatuses([]oauth.Status{status})); err != nil {
 		return exitCrash
 	}
+	if line := ensureLoginProviderProfile(deps, provider); line != "" {
+		if _, err := fmt.Fprintln(stdout, line); err != nil {
+			return exitCrash
+		}
+	}
 	return exitSuccess
 }
 

internal/cli/auth_test.go

@@ -2,18 +2,24 @@ package cli
 
 import (
 	"bytes"
+	"encoding/json"
+	"os"
 	"path/filepath"
 	"strings"
 	"testing"
 
+	"github.com/Gitlawb/zero/internal/config"
 	"github.com/Gitlawb/zero/internal/oauth"
 )
 
-// withAuthStore points the provider OAuth store at a temp file for the test.
+// withAuthStore points the provider OAuth store at a temp file for the test,
+// pinning the file backend so an inherited ZERO_OAUTH_STORAGE=keyring can't
+// ignore the temp path and hit the OS keychain.
 func withAuthStore(t *testing.T) string {
 	t.Helper()
 	path := filepath.Join(t.TempDir(), "oauth-tokens.json")
 	t.Setenv("ZERO_OAUTH_TOKENS_PATH", path)
+	t.Setenv("ZERO_OAUTH_STORAGE", "file")
 	return path
 }
 
@@ -197,3 +203,81 @@ func TestRunAuthLoginChatGPTRejectsScope(t *testing.T) {
 		t.Fatalf("stderr = %q, want the ChatGPT-specific --scope rejection", stderr.String())
 	}
 }
+
+func TestEnsureLoginProviderProfileAddsProviderWithoutStealingActive(t *testing.T) {
+	configPath := filepath.Join(t.TempDir(), "config.json")
+	seed := `{"activeProvider":"opengateway","providers":[{"name":"opengateway","provider_kind":"openai-compatible","baseURL":"https://gateway.example.com/v1","apiKeyStored":true,"model":"some-model"}]}`
+	if err := os.WriteFile(configPath, []byte(seed), 0o600); err != nil {
+		t.Fatalf("seed config: %v", err)
+	}
+	deps := appDeps{userConfigPath: func() (string, error) { return configPath, nil }}
+
+	line := ensureLoginProviderProfile(deps, "chatgpt")
+	if !strings.Contains(line, `Added provider "chatgpt"`) {
+		t.Fatalf("expected added-provider guidance, got %q", line)
+	}
+	if !strings.Contains(line, "zero providers use chatgpt") {
+		t.Fatalf("expected switch hint, got %q", line)
+	}
+
+	cfg := readCLIConfigFixture(t, configPath)
+	if cfg.ActiveProvider != "opengateway" {
+		t.Fatalf("active provider changed to %q", cfg.ActiveProvider)
+	}
+	names := make([]string, 0, len(cfg.Providers))
+	for _, provider := range cfg.Providers {
+		names = append(names, provider.Name)
+	}
+	if len(cfg.Providers) != 2 || cfg.Providers[1].CatalogID != "chatgpt" {
+		t.Fatalf("expected chatgpt profile appended, got %v", names)
+	}
+
+	// A second login must be a no-op with switch guidance, not a duplicate.
+	line = ensureLoginProviderProfile(deps, "chatgpt")
+	if !strings.Contains(line, "already configured") {
+		t.Fatalf("expected already-configured guidance, got %q", line)
+	}
+	cfg = readCLIConfigFixture(t, configPath)
+	if len(cfg.Providers) != 2 {
+		t.Fatalf("repeat login duplicated the profile: %d providers", len(cfg.Providers))
+	}
+}
+
+func TestEnsureLoginProviderProfileActivatesOnFreshConfig(t *testing.T) {
+	configPath := filepath.Join(t.TempDir(), "config.json")
+	deps := appDeps{userConfigPath: func() (string, error) { return configPath, nil }}
+
+	line := ensureLoginProviderProfile(deps, "chatgpt")
+	if !strings.Contains(line, "set it active") {
+		t.Fatalf("fresh config should adopt the login as active, got %q", line)
+	}
+	cfg := readCLIConfigFixture(t, configPath)
+	if cfg.ActiveProvider != "chatgpt" {
+		t.Fatalf("active provider = %q, want chatgpt", cfg.ActiveProvider)
+	}
+}
+
+func TestEnsureLoginProviderProfileSkipsNonCatalogProviders(t *testing.T) {
+	configPath := filepath.Join(t.TempDir(), "config.json")
+	deps := appDeps{userConfigPath: func() (string, error) { return configPath, nil }}
+
+	if line := ensureLoginProviderProfile(deps, "my-custom-oauth-server"); line != "" {
+		t.Fatalf("custom OAuth server must not scaffold a profile, got %q", line)
+	}
+	if _, err := os.Stat(configPath); err == nil {
+		t.Fatalf("config must not be created for a non-catalog login")
+	}
+}
+
+func readCLIConfigFixture(t *testing.T, path string) config.FileConfig {
+	t.Helper()
+	data, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("read config: %v", err)
+	}
+	var cfg config.FileConfig
+	if err := json.Unmarshal(data, &cfg); err != nil {
+		t.Fatalf("decode config: %v", err)
+	}
+	return cfg
+}

internal/cli/command_center.go

@@ -75,6 +75,12 @@ func runProviders(args []string, stdout io.Writer, stderr io.Writer, deps appDep
 	if command == "use" {
 		return runProvidersUse(args, stdout, stderr, deps)
 	}
+	if command == "remove" || command == "rm" {
+		return runProvidersRemove(args, stdout, stderr, deps)
+	}
+	if command == "rename" {
+		return runProvidersRename(args, stdout, stderr, deps)
+	}
 	if command == "setup" {
 		return runProvidersSetup(args, stdout, stderr, deps)
 	}
@@ -246,6 +252,20 @@ func parseCommandCenterArgs(args []string, allowModelFilters bool, allowProvider
 
 func summarizeConfig(resolved config.ResolvedConfig) configSummary {
 	summary := zerocommands.ConfigSnapshotFromResolved(resolved)
+	// Mark keyless profiles that authenticate via a stored OAuth login (e.g.
+	// ChatGPT) so the list shows "oauth login" instead of "api key: not set" —
+	// the same candidate matching the runtime resolver uses.
+	logins := oauthLoggedInProviders()
+	if len(logins) > 0 {
+		for index := range summary.Providers {
+			for _, profile := range resolved.Providers {
+				if profile.Name == summary.Providers[index].Name {
+					summary.Providers[index].OAuthLogin = providerHasOAuthLogin(profile, logins)
+					break
+				}
+			}
+		}
+	}
 	sort.SliceStable(summary.Providers, func(i int, j int) bool {
 		if summary.Providers[i].Active != summary.Providers[j].Active {
 			return summary.Providers[i].Active
@@ -323,7 +343,7 @@ func formatProviderSummaries(command string, providers []providerSummary) string
 				"model: "+displayCLIValue(provider.Model, "none"),
 				"api model: "+displayCLIValue(provider.APIModel, "unknown"),
 				"base url: "+displayCLIValue(provider.BaseURL, "default"),
-				"api key: "+apiKeyState(provider.APIKeySet),
+				"api key: "+providerCredentialState(provider),
 			)
 			if provider.Message != "" {
 				lines = append(lines, "status: "+provider.Status+" - "+provider.Message)
@@ -340,7 +360,7 @@ func formatProviderLine(provider providerSummary) string {
 	if provider.Active {
 		marker = "*"
 	}
-	line := fmt.Sprintf("%s %s [%s] model=%s apiModel=%s api key: %s", marker, displayCLIValue(provider.Name, "none"), displayCLIValue(provider.ProviderKind, "unknown"), displayCLIValue(provider.Model, "none"), displayCLIValue(provider.APIModel, "unknown"), apiKeyState(provider.APIKeySet))
+	line := fmt.Sprintf("%s %s [%s] model=%s apiModel=%s api key: %s", marker, displayCLIValue(provider.Name, "none"), displayCLIValue(provider.ProviderKind, "unknown"), displayCLIValue(provider.Model, "none"), displayCLIValue(provider.APIModel, "unknown"), providerCredentialState(provider))
 	if provider.Message != "" {
 		line += " (" + provider.Status + ": " + provider.Message + ")"
 	}
@@ -413,6 +433,15 @@ func apiKeyState(set bool) string {
 	return "not set"
 }
 
+// providerCredentialState renders the credential column: a configured key wins,
+// then a stored OAuth login, then "not set".
+func providerCredentialState(provider providerSummary) string {
+	if !provider.APIKeySet && provider.OAuthLogin {
+		return "oauth login"
+	}
+	return apiKeyState(provider.APIKeySet)
+}
+
 func displayCLIValue(value string, fallback string) string {
 	if strings.TrimSpace(value) == "" {
 		return fallback
@@ -466,6 +495,8 @@ func writeProvidersHelp(w io.Writer) error {
   zero providers add <catalog-id> [flags]
   zero providers check [name] [flags]
   zero providers use <name> [flags]
+  zero providers remove <name> [flags]
+  zero providers rename <old> <new> [flags]
   zero providers setup <catalog-id> [flags]
   zero providers detect [flags]
   zero providers models [name] [flags]

internal/cli/command_center_test.go

@@ -11,6 +11,7 @@ import (
 	"testing"
 
 	"github.com/Gitlawb/zero/internal/config"
+	"github.com/Gitlawb/zero/internal/oauth"
 	"github.com/Gitlawb/zero/internal/providerhealth"
 	"github.com/Gitlawb/zero/internal/zerocommands"
 	"github.com/Gitlawb/zero/internal/zeroruntime"
@@ -835,3 +836,57 @@ func (commandCenterProvider) StreamCompletion(context.Context, zeroruntime.Compl
 	close(ch)
 	return ch, nil
 }
+
+func TestProviderCredentialStateShowsOAuthLogin(t *testing.T) {
+	if got := providerCredentialState(providerSummary{APIKeySet: true}); got != "set" {
+		t.Fatalf("keyed provider = %q, want set", got)
+	}
+	if got := providerCredentialState(providerSummary{OAuthLogin: true}); got != "oauth login" {
+		t.Fatalf("token-login provider = %q, want oauth login", got)
+	}
+	if got := providerCredentialState(providerSummary{}); got != "not set" {
+		t.Fatalf("credential-less provider = %q, want not set", got)
+	}
+}
+
+// TestProvidersListMarksOAuthLoginProviders: a keyless profile whose credential
+// is a stored OAuth login (the shape `zero auth chatgpt` now writes) must render
+// as "oauth login", not as a broken "api key: not set" entry.
+func TestProvidersListMarksOAuthLoginProviders(t *testing.T) {
+	tokensPath := filepath.Join(t.TempDir(), "oauth-tokens.json")
+	t.Setenv("ZERO_OAUTH_TOKENS_PATH", tokensPath)
+	store, err := oauth.NewStore(oauth.StoreOptions{})
+	if err != nil {
+		t.Fatalf("oauth store: %v", err)
+	}
+	if err := store.Save(oauth.ProviderKey("chatgpt"), oauth.Token{AccessToken: "bearer-123"}); err != nil {
+		t.Fatalf("save token: %v", err)
+	}
+
+	resolved := config.ResolvedConfig{
+		ActiveProvider: "opengateway",
+		Providers: []config.ProviderProfile{
+			{Name: "opengateway", ProviderKind: config.ProviderKindOpenAICompatible, BaseURL: "https://gateway.example.com/v1", APIKeyStored: true, Model: "some-model"},
+			{Name: "chatgpt", CatalogID: "chatgpt", ProviderKind: config.ProviderKindOpenAICompatible, BaseURL: "https://chatgpt.com/backend-api/codex", Model: "gpt-5.5"},
+		},
+	}
+	summary := summarizeConfig(resolved)
+	byName := map[string]providerSummary{}
+	for _, provider := range summary.Providers {
+		byName[provider.Name] = provider
+	}
+	if !byName["opengateway"].APIKeySet {
+		t.Fatalf("stored-key provider must report a credential: %+v", byName["opengateway"])
+	}
+	if byName["opengateway"].OAuthLogin {
+		t.Fatalf("key-authed provider must not claim the OAuth login: %+v", byName["opengateway"])
+	}
+	if !byName["chatgpt"].OAuthLogin || byName["chatgpt"].APIKeySet {
+		t.Fatalf("chatgpt must be marked oauth-login and keyless: %+v", byName["chatgpt"])
+	}
+
+	rendered := formatProviderSummaries("list", summary.Providers)
+	if !strings.Contains(rendered, "oauth login") {
+		t.Fatalf("list should render the oauth login state, got:\n%s", rendered)
+	}
+}

internal/cli/dictation.go

@@ -0,0 +1,248 @@
+package cli
+
+import (
+	"fmt"
+	neturl "net/url"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/Gitlawb/zero/internal/config"
+	"github.com/Gitlawb/zero/internal/dictation"
+	"github.com/Gitlawb/zero/internal/tui"
+)
+
+// Default batch cloud models (§8). Overridable via stt.model.
+const (
+	defaultGroqSTTModel   = "whisper-large-v3-turbo"
+	defaultOpenAISTTModel = "whisper-1"
+	groqSTTBaseURL        = "https://api.groq.com/openai/v1"
+)
+
+// newDictationTranscriberFactory returns the closure the TUI calls to build a
+// transcriber when a recording starts. It lives here, not in the TUI, because it
+// resolves provider API keys (credstore + env + configured providers) — logic
+// that belongs with the rest of the CLI's credential handling.
+//
+// serverMgr is the shared, session-long sherpa-onnx streaming server; it is
+// spawned lazily on the first local-streaming recording and torn down on exit.
+//
+// preferStreaming asks for the streaming backend; the returned bool reports
+// whether streaming was actually built (false → the caller uses the batch
+// pipeline). A misconfigured streaming backend surfaces its own SetupError.
+func newDictationTranscriberFactory(resolved config.ResolvedConfig, userConfigPath string, serverMgr *dictation.ServerManager) func(config.STTConfig, bool) (tui.Transcriber, bool, error) {
+	return func(stt config.STTConfig, preferStreaming bool) (tui.Transcriber, bool, error) {
+		// stt is passed in (not captured) so a mid-session change — e.g. the F9
+		// auto-download writing localModelPath — takes effect on the next call.
+		if serverMgr != nil {
+			serverMgr.SetModelPath(stt.LocalModelPath)
+		}
+		if preferStreaming {
+			t, err := buildStreamingTranscriber(stt, resolved, userConfigPath, serverMgr)
+			switch {
+			case err == nil && t != nil:
+				return t, true, nil
+			case err != nil && stt.STTStreamProvider() != config.STTProviderLocal:
+				// An explicitly-chosen cloud streaming backend that failed to build
+				// (e.g. a missing key) should surface its own error, not silently
+				// fall back to batch — the user asked for that backend specifically.
+				return nil, true, err
+			}
+			// The default local streaming backend isn't set up: fall through to the
+			// batch pipeline so a cloud-batch provider (or a batch-only setup) still
+			// works instead of erroring on a streaming server the user never asked for.
+		}
+		t, err := buildBatchTranscriber(stt, resolved, userConfigPath)
+		return t, false, err
+	}
+}
+
+// buildStreamingTranscriber constructs the configured streaming backend, or
+// returns (nil, nil) when streaming is not applicable so the caller falls back
+// to batch.
+func buildStreamingTranscriber(stt config.STTConfig, resolved config.ResolvedConfig, userConfigPath string, serverMgr *dictation.ServerManager) (dictation.Transcriber, error) {
+	switch stt.STTStreamProvider() {
+	case config.STTProviderDeepgram:
+		key := resolveSTTKey(resolved, userConfigPath, dictation.StreamProviderDeepgram, "DEEPGRAM_API_KEY")
+		return dictation.NewDeepgramTranscriber(dictation.DeepgramConfig{
+			APIKey:   key,
+			Model:    stt.StreamModel,
+			Language: stt.Language,
+		})
+	case config.STTProviderOpenAI:
+		key := resolveSTTKey(resolved, userConfigPath, dictation.ProviderOpenAI, "OPENAI_API_KEY")
+		return dictation.NewOpenAIRealtimeTranscriber(dictation.OpenAIRealtimeConfig{
+			APIKey: key,
+			Model:  stt.StreamModel,
+		})
+	default: // local streaming via the warm sherpa-onnx server
+		// STTStreamProvider() defaults to "local" whenever streamProvider is unset —
+		// including when the user picked a CLOUD batch provider (Groq/OpenAI) and
+		// never touched streaming. Don't silently stream through the local sherpa
+		// server in that case: local streaming is only appropriate when it was
+		// explicitly requested (streamProvider: "local") OR the batch provider is
+		// itself local. Otherwise report "not applicable" so the factory falls back
+		// to the cloud batch pipeline the user actually chose.
+		localWanted := stt.StreamProvider == config.STTProviderLocal || stt.STTProvider() == config.STTProviderLocal
+		if !localWanted {
+			return nil, nil
+		}
+		// The local streaming transcriber validates the model only lazily (at
+		// connect time), so gate on the model path here — with none set, report
+		// "not applicable" (nil, nil) so the factory falls back to the batch
+		// pipeline instead of committing to a server that can't start.
+		if serverMgr == nil || strings.TrimSpace(stt.LocalModelPath) == "" {
+			return nil, nil
+		}
+		return dictation.NewLocalStreamingTranscriber(serverMgr), nil
+	}
+}
+
+// newDictationServerManager builds the warm sherpa-onnx streaming server manager
+// from config. Construction is side-effect free — the server spawns lazily on
+// the first local-streaming recording — so it is always safe to create.
+func newDictationServerManager(stt config.STTConfig) *dictation.ServerManager {
+	return dictation.NewServerManager(dictation.ServerConfig{
+		Binary:     stt.LocalServerBinary,
+		ModelPath:  stt.LocalModelPath,
+		Port:       stt.LocalServerPort,
+		NumThreads: stt.NumThreads,
+	})
+}
+
+// buildBatchTranscriber constructs the configured batch transcriber, resolving
+// credentials for the cloud providers.
+func buildBatchTranscriber(stt config.STTConfig, resolved config.ResolvedConfig, userConfigPath string) (dictation.Transcriber, error) {
+	switch stt.STTProvider() {
+	case config.STTProviderGroq:
+		key := resolveSTTKey(resolved, userConfigPath, dictation.ProviderGroq, "GROQ_API_KEY")
+		model := stt.Model
+		if model == "" {
+			model = defaultGroqSTTModel
+		}
+		return dictation.NewCloudTranscriber(dictation.CloudConfig{
+			Provider: dictation.ProviderGroq,
+			BaseURL:  groqSTTBaseURL,
+			APIKey:   key,
+			Model:    model,
+			Language: stt.Language,
+		})
+	case config.STTProviderOpenAI:
+		key := resolveSTTKey(resolved, userConfigPath, dictation.ProviderOpenAI, "OPENAI_API_KEY")
+		model := stt.Model
+		if model == "" {
+			model = defaultOpenAISTTModel
+		}
+		return dictation.NewCloudTranscriber(dictation.CloudConfig{
+			Provider: dictation.ProviderOpenAI,
+			BaseURL:  config.OpenAIBaseURL,
+			APIKey:   key,
+			Model:    model,
+			Language: stt.Language,
+		})
+	default: // local
+		return dictation.NewLocalTranscriber(dictation.LocalConfig{
+			Binary:     stt.LocalBinary,
+			ModelPath:  stt.LocalModelPath,
+			NumThreads: stt.NumThreads,
+		})
+	}
+}
+
+// sttEnvVar returns the conventional environment variable a cloud STT provider's
+// key is read from.
+func sttEnvVar(provider string) string {
+	switch provider {
+	case dictation.ProviderGroq:
+		return "GROQ_API_KEY"
+	case dictation.ProviderOpenAI: // == StreamProviderOpenAI ("openai")
+		return "OPENAI_API_KEY"
+	case dictation.StreamProviderDeepgram:
+		return "DEEPGRAM_API_KEY"
+	}
+	return ""
+}
+
+// newSTTKeyStatus returns a predicate reporting whether a cloud STT provider
+// already has a resolvable API key (configured provider, credstore, or env).
+func newSTTKeyStatus(resolved config.ResolvedConfig, userConfigPath string) func(string) bool {
+	return func(provider string) bool {
+		return resolveSTTKey(resolved, userConfigPath, provider, sttEnvVar(provider)) != ""
+	}
+}
+
+// newSaveSTTKey returns a function that stores a cloud STT provider's API key in
+// the encrypted credential store, so the inline prompt can persist it.
+func newSaveSTTKey(userConfigPath string) func(string, string) error {
+	return func(provider, key string) error {
+		if strings.TrimSpace(userConfigPath) == "" {
+			return fmt.Errorf("no config path to store the key")
+		}
+		store, err := config.ProviderKeyStoreAt(filepath.Dir(userConfigPath))
+		if err != nil {
+			return err
+		}
+		return store.Set(provider, strings.TrimSpace(key))
+	}
+}
+
+// resolveSTTKey finds an API key for an STT cloud provider, reusing Zero's
+// existing credentials (§2 — "zero new credential UI"). Precedence: a matching
+// configured provider's resolved key, then the encrypted credential store, then
+// the provider's conventional environment variable.
+func resolveSTTKey(resolved config.ResolvedConfig, userConfigPath, provider, envVar string) string {
+	if key := keyFromConfiguredProviders(resolved, provider); key != "" {
+		return key
+	}
+	if userConfigPath != "" {
+		if store, err := config.ProviderKeyStoreAt(filepath.Dir(userConfigPath)); err == nil {
+			if key, ok, _ := store.Get(provider); ok && strings.TrimSpace(key) != "" {
+				return strings.TrimSpace(key)
+			}
+		}
+	}
+	return strings.TrimSpace(os.Getenv(envVar))
+}
+
+// keyFromConfiguredProviders returns the resolved API key of a configured
+// provider that belongs to the given cloud provider (matched by catalog id,
+// provider name/kind, or base-URL host), or "" when none is configured.
+func keyFromConfiguredProviders(resolved config.ResolvedConfig, provider string) string {
+	provider = strings.ToLower(provider)
+	profiles := append([]config.ProviderProfile{resolved.Provider}, resolved.Providers...)
+	for _, p := range profiles {
+		if strings.TrimSpace(p.APIKey) == "" {
+			continue
+		}
+		if providerMatches(p, provider) {
+			return strings.TrimSpace(p.APIKey)
+		}
+	}
+	return ""
+}
+
+func providerMatches(p config.ProviderProfile, provider string) bool {
+	provider = strings.ToLower(provider)
+	// Match on stable identifiers (catalog id, provider name/kind, profile
+	// name) rather than raw BaseURL substring matching: a Groq profile's
+	// BaseURL (api.groq.com/openai/v1) contains "openai", so a substring
+	// check can hand the wrong key to an OpenAI STT lookup and fail auth.
+	for _, f := range []string{
+		strings.ToLower(p.CatalogID),
+		strings.ToLower(p.Provider),
+		strings.ToLower(string(p.ProviderKind)),
+		strings.ToLower(p.Name),
+	} {
+		if f != "" && strings.Contains(f, provider) {
+			return true
+		}
+	}
+	// BaseURL: compare the parsed host only, not a raw substring on the
+	// full URL (which lets "openai" match api.groq.com/openai/v1).
+	if u, err := neturl.Parse(p.BaseURL); err == nil && u.Host != "" {
+		if host := strings.ToLower(u.Host); strings.Contains(host, provider) {
+			return true
+		}
+	}
+	return false
+}

internal/cli/dictation_test.go

@@ -0,0 +1,96 @@
+package cli
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/Gitlawb/zero/internal/config"
+	"github.com/Gitlawb/zero/internal/dictation"
+)
+
+func TestFactoryFallsBackToBatchWhenLocalStreamingNotConfigured(t *testing.T) {
+	t.Setenv("GROQ_API_KEY", "gsk-test")
+	resolved := config.ResolvedConfig{STT: config.STTConfig{
+		Provider: config.STTProviderGroq, // cloud batch
+		// StreamProvider unset → defaults to local, which has no model configured.
+	}}
+	factory := newDictationTranscriberFactory(resolved, "", newDictationServerManager(resolved.STT))
+
+	tr, streaming, err := factory(resolved.STT, true) // prefer streaming
+	if err != nil {
+		t.Fatalf("expected batch fallback, got error: %v", err)
+	}
+	if streaming {
+		t.Error("should have fallen back to batch (streaming=false)")
+	}
+	if tr == nil {
+		t.Error("expected a Groq batch transcriber")
+	}
+}
+
+func TestFactoryCloudProviderIgnoresLeftoverLocalModel(t *testing.T) {
+	// Regression: pick local once (LocalModelPath gets set), then switch to a
+	// cloud batch provider. streamProvider stays unset (defaults to "local"), so
+	// the streaming factory must NOT fire up the sherpa server on the leftover
+	// path — it should fall back to the cloud batch pipeline the user chose.
+	t.Setenv("GROQ_API_KEY", "gsk-test")
+	stt := config.STTConfig{
+		Provider:       config.STTProviderGroq, // cloud batch, chosen now
+		LocalModelPath: "/leftover/model/dir",  // set by an earlier local selection
+	}
+	resolved := config.ResolvedConfig{STT: stt}
+	factory := newDictationTranscriberFactory(resolved, "", newDictationServerManager(stt))
+
+	tr, streaming, err := factory(stt, true) // prefer streaming
+	if err != nil {
+		t.Fatalf("expected cloud batch fallback, got error: %v", err)
+	}
+	if streaming {
+		t.Error("a cloud provider must not stream through the local sherpa server")
+	}
+	if tr == nil {
+		t.Error("expected a Groq batch transcriber")
+	}
+}
+
+func TestFactorySurfacesExplicitCloudStreamingError(t *testing.T) {
+	// Deepgram chosen explicitly but no key resolvable → surface the setup error.
+	resolved := config.ResolvedConfig{STT: config.STTConfig{
+		StreamProvider: config.STTProviderDeepgram,
+	}}
+	factory := newDictationTranscriberFactory(resolved, "", nil)
+
+	_, streaming, err := factory(resolved.STT, true)
+	if err == nil {
+		t.Fatal("expected a setup error for missing Deepgram key")
+	}
+	if !streaming {
+		t.Error("an explicit cloud streaming choice should report streaming=true even on error")
+	}
+	var setupErr *dictation.SetupError
+	if !errors.As(err, &setupErr) {
+		t.Errorf("want *SetupError, got %v", err)
+	}
+}
+
+func TestFactoryLocalBatchSetupErrorWhenNoModel(t *testing.T) {
+	resolved := config.ResolvedConfig{STT: config.STTConfig{Provider: config.STTProviderLocal}}
+	factory := newDictationTranscriberFactory(resolved, "", newDictationServerManager(resolved.STT))
+
+	_, _, err := factory(resolved.STT, true)
+	var setupErr *dictation.SetupError
+	if !errors.As(err, &setupErr) {
+		t.Fatalf("want *SetupError guiding local model setup, got %v", err)
+	}
+}
+
+func TestResolveSTTKeyPrefersConfiguredProvider(t *testing.T) {
+	resolved := config.ResolvedConfig{
+		Providers: []config.ProviderProfile{
+			{Name: "groq", CatalogID: "groq", BaseURL: "https://api.groq.com/openai/v1", APIKey: "gsk-configured"},
+		},
+	}
+	if got := resolveSTTKey(resolved, "", dictation.ProviderGroq, "GROQ_API_KEY"); got != "gsk-configured" {
+		t.Errorf("key = %q, want the configured provider's key", got)
+	}
+}

internal/cli/provider_models.go

@@ -8,6 +8,7 @@ import (
 	"strings"
 
 	"github.com/Gitlawb/zero/internal/config"
+	"github.com/Gitlawb/zero/internal/providermodelcatalog"
 	"github.com/Gitlawb/zero/internal/providermodeldiscovery"
 )
 
@@ -51,6 +52,19 @@ func runProvidersModels(args []string, stdout io.Writer, stderr io.Writer, deps
 		return writeAppError(stderr, err.Error(), exitProvider)
 	}
 
+	// Apply provider-specific model filtering for catalog-backed profiles.
+	// For example, opencode-go-anthropic-compatible only permits Qwen and
+	// MiniMax model IDs; the raw /zen/go/v1/models endpoint returns many more.
+	if profile.CatalogID != "" {
+		filtered := make([]providermodeldiscovery.Model, 0, len(models))
+		for _, model := range models {
+			if providermodelcatalog.ModelIDAllowedForProvider(profile.CatalogID, model.ID) {
+				filtered = append(filtered, model)
+			}
+		}
+		models = filtered
+	}
+
 	if options.json {
 		items := make([]map[string]any, 0, len(models))
 		for _, model := range models {

internal/cli/provider_models_test.go

@@ -132,6 +132,62 @@ func TestRunProvidersModelsUnknownProviderFails(t *testing.T) {
 	}
 }
 
+func TestRunProvidersModelsFiltersForCatalogProfile(t *testing.T) {
+	var stdout bytes.Buffer
+	var stderr bytes.Buffer
+	deps := commandCenterDeps(t)
+	// Override the resolved config to include a catalog-backed profile.
+	deps.resolveConfig = func(_ string, _ config.Overrides) (config.ResolvedConfig, error) {
+		profile := config.ProviderProfile{
+			Name:         "opencode-go",
+			ProviderKind: config.ProviderKindAnthropicCompat,
+			CatalogID:    "opencode-go-anthropic-compatible",
+			BaseURL:      "https://api.example.com/zen/go/v1",
+			APIKey:       "sk-test",
+			Model:        "minimax-max",
+		}
+		return config.ResolvedConfig{
+			ActiveProvider: "opencode-go",
+			Providers:      []config.ProviderProfile{profile},
+			Provider:       profile,
+		}, nil
+	}
+	deps.discoverProviderModels = func(_ context.Context, _ config.ProviderProfile) ([]providermodeldiscovery.Model, error) {
+		return []providermodeldiscovery.Model{
+			{ID: "deepseek-chat", Description: "DeepSeek Chat"},
+			{ID: "qwen-max", Description: "Qwen Max"},
+			{ID: "minimax-max-01", Description: "MiniMax Max"},
+			{ID: "kimi-k2", Description: "Kimi K2"},
+			{ID: "glm-4", Description: "GLM-4"},
+		}, nil
+	}
+
+	exitCode := runWithDeps([]string{"providers", "models"}, &stdout, &stderr, deps)
+
+	if exitCode != exitSuccess {
+		t.Fatalf("exit = %d, want %d: %s", exitCode, exitSuccess, stderr.String())
+	}
+	out := stdout.String()
+	// Only Qwen and MiniMax model IDs should survive the filter.
+	if strings.Contains(out, "deepseek-chat") {
+		t.Error("output should not contain deepseek-chat (blocked by opencode-go-anthropic filter)")
+	}
+	if strings.Contains(out, "kimi-k2") {
+		t.Error("output should not contain kimi-k2 (blocked by opencode-go-anthropic filter)")
+	}
+	if strings.Contains(out, "glm-4") {
+		t.Error("output should not contain glm-4 (blocked by opencode-go-anthropic filter)")
+	}
+	for _, want := range []string{"qwen-max", "minimax-max-01"} {
+		if !strings.Contains(out, want) {
+			t.Fatalf("output missing allowed model %q:\n%s", want, out)
+		}
+	}
+	if !strings.Contains(out, "2 models discovered") {
+		t.Fatalf("output should show 2 models:\n%s", out)
+	}
+}
+
 func TestRunProvidersModelsSurfacesDiscoveryError(t *testing.T) {
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer

internal/cli/provider_onboarding.go

@@ -3,6 +3,7 @@ package cli
 import (
 	"fmt"
 	"io"
+	"path/filepath"
 	"strconv"
 	"strings"
 	"unicode"
@@ -306,3 +307,143 @@ func providerCommandArg(value string) string {
 	}
 	return value
 }
+
+type providerNamesOptions struct {
+	names []string
+	json  bool
+}
+
+func parseProviderNamesArgs(args []string, want int, usage string) (providerNamesOptions, bool, error) {
+	options := providerNamesOptions{}
+	for _, arg := range args {
+		switch {
+		case arg == "-h" || arg == "--help" || arg == "help":
+			return options, true, nil
+		case arg == "--json":
+			options.json = true
+		case strings.HasPrefix(arg, "-"):
+			return options, false, execUsageError{fmt.Sprintf("unknown flag %q", arg)}
+		default:
+			options.names = append(options.names, arg)
+		}
+	}
+	if len(options.names) != want {
+		return options, false, execUsageError{usage}
+	}
+	return options, false, nil
+}
+
+// runProvidersRemove deletes a saved provider profile and its stored API key.
+// The OAuth token (if any) is kept — logins outlive profiles so re-adding the
+// provider needs no new browser round-trip; `zero auth logout <name>` removes it.
+func runProvidersRemove(args []string, stdout io.Writer, stderr io.Writer, deps appDeps) int {
+	options, help, err := parseProviderNamesArgs(args, 1, "usage: zero providers remove <name>")
+	if err != nil {
+		return writeExecUsageError(stderr, err.Error())
+	}
+	if help {
+		if err := writeProvidersHelp(stdout); err != nil {
+			return exitCrash
+		}
+		return exitSuccess
+	}
+	configPath, err := deps.userConfigPath()
+	if err != nil {
+		return writeAppError(stderr, err.Error(), exitCrash)
+	}
+	name := options.names[0]
+	cfg, err := config.RemoveProvider(configPath, name)
+	if err != nil {
+		return writeAppError(stderr, err.Error(), exitCrash)
+	}
+	// Delete the key from the store BESIDE the config being edited — the same
+	// store setup/rename write to — not the default-path store, so a
+	// non-default config path cannot leave the encrypted key behind.
+	keyRemoved, keyErr := removeStoredProviderKeyAt(configPath, name)
+	if options.json {
+		payload := map[string]any{
+			"removed":        name,
+			"keyRemoved":     keyRemoved,
+			"activeProvider": cfg.ActiveProvider,
+			"configPath":     configPath,
+		}
+		if keyErr != nil {
+			// A lingering secret must not read as a clean removal.
+			payload["keyError"] = keyErr.Error()
+		}
+		if err := writePrettyJSON(stdout, payload); err != nil {
+			return exitCrash
+		}
+		return exitSuccess
+	}
+	if _, err := fmt.Fprintf(stdout, "Removed provider %s\n", name); err != nil {
+		return exitCrash
+	}
+	if keyErr != nil {
+		if _, err := fmt.Fprintf(stderr, "warning: its stored API key could not be deleted and remains in the credential store: %v\n", keyErr); err != nil {
+			return exitCrash
+		}
+	} else if keyRemoved {
+		if _, err := fmt.Fprintln(stdout, "Deleted its stored API key."); err != nil {
+			return exitCrash
+		}
+	}
+	if active := strings.TrimSpace(cfg.ActiveProvider); active != "" {
+		if _, err := fmt.Fprintf(stdout, "Active provider: %s\n", active); err != nil {
+			return exitCrash
+		}
+	} else {
+		if _, err := fmt.Fprintln(stdout, "No providers remain — run zero setup to add one."); err != nil {
+			return exitCrash
+		}
+	}
+	return exitSuccess
+}
+
+// removeStoredProviderKeyAt deletes a provider's API key from the credential
+// store co-located with configPath (the store SecureProviderProfile captured
+// it into and RenameProvider migrates within).
+func removeStoredProviderKeyAt(configPath string, provider string) (bool, error) {
+	store, err := config.ProviderKeyStoreAt(filepath.Dir(configPath))
+	if err != nil {
+		return false, err
+	}
+	return store.Delete(provider)
+}
+
+// runProvidersRename renames a saved provider profile, migrating its stored
+// API key and the activeProvider pointer along with it (config.RenameProvider).
+func runProvidersRename(args []string, stdout io.Writer, stderr io.Writer, deps appDeps) int {
+	options, help, err := parseProviderNamesArgs(args, 2, "usage: zero providers rename <old> <new>")
+	if err != nil {
+		return writeExecUsageError(stderr, err.Error())
+	}
+	if help {
+		if err := writeProvidersHelp(stdout); err != nil {
+			return exitCrash
+		}
+		return exitSuccess
+	}
+	configPath, err := deps.userConfigPath()
+	if err != nil {
+		return writeAppError(stderr, err.Error(), exitCrash)
+	}
+	cfg, err := config.RenameProvider(configPath, options.names[0], options.names[1])
+	if err != nil {
+		return writeAppError(stderr, err.Error(), exitCrash)
+	}
+	if options.json {
+		if err := writePrettyJSON(stdout, map[string]any{
+			"renamed":        map[string]string{"from": options.names[0], "to": options.names[1]},
+			"activeProvider": cfg.ActiveProvider,
+			"configPath":     configPath,
+		}); err != nil {
+			return exitCrash
+		}
+		return exitSuccess
+	}
+	if _, err := fmt.Fprintf(stdout, "Renamed provider %s to %s\n", options.names[0], options.names[1]); err != nil {
+		return exitCrash
+	}
+	return exitSuccess
+}

internal/cli/provider_onboarding_test.go

@@ -234,3 +234,48 @@ func writeProviderOnboardingConfig(t *testing.T, path string, cfg config.FileCon
 		t.Fatalf("write config: %v", err)
 	}
 }
+
+// TestRunProvidersRemoveDeletesKeyBesideConfig: the stored key must be deleted
+// from the credential store CO-LOCATED with the config being edited (where
+// SecureProviderProfile captured it), not the default-path store.
+func TestRunProvidersRemoveDeletesKeyBesideConfig(t *testing.T) {
+	t.Setenv("ZERO_CRED_STORAGE", "encrypted-file")
+	dir := t.TempDir()
+	configPath := filepath.Join(dir, "config.json")
+	seed := `{"activeProvider":"gw","providers":[{"name":"gw","provider_kind":"openai-compatible","baseURL":"https://gw.example.com/v1","apiKeyStored":true,"model":"m1"},{"name":"other","provider_kind":"openai-compatible","baseURL":"https://o.example.com/v1","model":"m2"}]}`
+	if err := os.WriteFile(configPath, []byte(seed), 0o600); err != nil {
+		t.Fatalf("seed config: %v", err)
+	}
+	store, err := config.ProviderKeyStoreAt(dir)
+	if err != nil {
+		t.Fatalf("open store: %v", err)
+	}
+	if err := store.Set("gw", "sk-secret"); err != nil {
+		t.Fatalf("seed key: %v", err)
+	}
+
+	var stdout, stderr bytes.Buffer
+	deps := appDeps{userConfigPath: func() (string, error) { return configPath, nil }}
+	if code := runWithDeps([]string{"providers", "remove", "gw", "--json"}, &stdout, &stderr, deps); code != exitSuccess {
+		t.Fatalf("remove failed: code=%d stderr=%s", code, stderr.String())
+	}
+
+	var payload struct {
+		Removed        string `json:"removed"`
+		KeyRemoved     bool   `json:"keyRemoved"`
+		KeyError       string `json:"keyError"`
+		ActiveProvider string `json:"activeProvider"`
+	}
+	if err := json.Unmarshal(stdout.Bytes(), &payload); err != nil {
+		t.Fatalf("decode JSON: %v\n%s", err, stdout.String())
+	}
+	if payload.Removed != "gw" || !payload.KeyRemoved || payload.KeyError != "" {
+		t.Fatalf("unexpected payload: %+v", payload)
+	}
+	if payload.ActiveProvider != "other" {
+		t.Fatalf("active must hand off, got %q", payload.ActiveProvider)
+	}
+	if _, ok, _ := store.Get("gw"); ok {
+		t.Fatalf("stored key must be deleted from the store beside the config")
+	}
+}

internal/cli/provider_setup.go

@@ -457,7 +457,9 @@ func selectProviderForCheck(resolved config.ResolvedConfig, name string) (config
 }
 
 func validateProviderRuntimeReady(profile config.ProviderProfile) error {
-	hasCredential := providerProfileHasCredential(profile)
+	// A stored OAuth login (e.g. `zero auth chatgpt`) is a credential too: a
+	// keyless token-login profile must pass the readiness check instead of being
+	// told to set an API key it will never have.
 	if profile.CatalogID != "" {
 		descriptor, err := providercatalog.Require(profile.CatalogID)
 		if err != nil {
@@ -466,23 +468,19 @@ func validateProviderRuntimeReady(profile config.ProviderProfile) error {
 		if !providercatalog.RuntimeSupported(descriptor) {
 			return fmt.Errorf("provider %q uses transport %q: %s", descriptor.ID, descriptor.Transport, providercatalog.RuntimeUnsupportedReason(descriptor))
 		}
-		if descriptor.RequiresAuth && !hasCredential {
-			apiKeyEnv := strings.TrimSpace(profile.APIKeyEnv)
-			if apiKeyEnv == "" && len(descriptor.AuthEnvVars) > 0 {
-				apiKeyEnv = descriptor.AuthEnvVars[0]
-			}
-			if apiKeyEnv != "" {
-				return fmt.Errorf("provider %s requires API key; set %s", profile.Name, apiKeyEnv)
-			}
-			return fmt.Errorf("provider %s requires API key", profile.Name)
-		}
+	}
+	if providerHasOAuthLogin(profile, oauthLoggedInProviders()) {
 		return nil
 	}
-	switch profile.ProviderKind {
-	case config.ProviderKindOpenAI, config.ProviderKindAnthropic, config.ProviderKindGoogle:
-		if !hasCredential {
-			return fmt.Errorf("provider %s requires API key", profile.Name)
+	// Delegates to the single source of truth shared with the TUI and the
+	// setup wizard, so `providers check` never disagrees with them about
+	// whether a saved provider (including a no-auth custom endpoint) is
+	// actually missing a credential.
+	if envVar, missing := profile.MissingCredentialEnv(); missing {
+		if envVar != "" {
+			return fmt.Errorf("provider %s requires API key; set %s", profile.Name, envVar)
 		}
+		return fmt.Errorf("provider %s requires API key", profile.Name)
 	}
 	return nil
 }

internal/cli/provider_setup_test.go

@@ -0,0 +1,68 @@
+package cli
+
+import (
+	"testing"
+
+	"github.com/Gitlawb/zero/internal/config"
+)
+
+// Regression for issue #555's follow-up: `zero providers check` must not
+// error that a no-auth custom endpoint requires an API key, matching what
+// /model and /providers already treat as usable.
+func TestValidateProviderRuntimeReadyCustomEndpoint(t *testing.T) {
+	cases := []struct {
+		name    string
+		profile config.ProviderProfile
+		wantErr bool
+	}{
+		{
+			name: "custom openai compatible with no credential configured",
+			profile: config.ProviderProfile{
+				Name:      "local-llama",
+				CatalogID: "custom-openai-compatible",
+				BaseURL:   "http://192.168.1.50:8080/v1",
+				Model:     "custom-model",
+			},
+			wantErr: false,
+		},
+		{
+			name: "custom openai compatible with stale legacy default env",
+			profile: config.ProviderProfile{
+				Name:      "local-llama",
+				CatalogID: "custom-openai-compatible",
+				BaseURL:   "http://192.168.1.50:8080/v1",
+				APIKeyEnv: "OPENAI_API_KEY",
+				Model:     "custom-model",
+			},
+			wantErr: false,
+		},
+		{
+			name: "custom openai compatible with explicit non-default env still requires it",
+			profile: config.ProviderProfile{
+				Name:      "local-llama",
+				CatalogID: "custom-openai-compatible",
+				BaseURL:   "http://192.168.1.50:8080/v1",
+				APIKeyEnv: "LLAMA_CPP_API_KEY",
+				Model:     "custom-model",
+			},
+			wantErr: true,
+		},
+		{
+			name: "catalog provider missing key still errors",
+			profile: config.ProviderProfile{
+				Name:      "groq",
+				CatalogID: "groq",
+				Model:     "llama-3.3-70b-versatile",
+			},
+			wantErr: true,
+		},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			err := validateProviderRuntimeReady(c.profile)
+			if (err != nil) != c.wantErr {
+				t.Fatalf("validateProviderRuntimeReady() error = %v, wantErr %v", err, c.wantErr)
+			}
+		})
+	}
+}

internal/cli/setup.go

@@ -322,7 +322,9 @@ func setupRequired(resolved config.ResolvedConfig) bool {
 // the candidate set is permissive (profile name + catalog ID).
 func providerHasOAuthLogin(profile config.ProviderProfile, oauthLogins map[string]bool) bool {
 	for _, name := range profile.OAuthLoginCandidates() {
-		if oauthLogins[name] {
+		// Store keys are normalized to lower case (oauth.ProviderKey), so the
+		// presence check must compare the same way.
+		if oauthLogins[strings.ToLower(strings.TrimSpace(name))] {
 			return true
 		}
 	}
@@ -344,18 +346,19 @@ func oauthLoggedInProviders() map[string]bool {
 	}
 	for _, status := range statuses {
 		if status.HasToken {
-			out[strings.TrimPrefix(status.Key, oauth.KeyPrefixProvider)] = true
+			out[strings.ToLower(strings.TrimPrefix(status.Key, oauth.KeyPrefixProvider))] = true
 		}
 	}
 	return out
 }
 
 // firstUsableProvider returns the saved provider best suited to run without
-// onboarding: the first usable (inline credential present, or no-auth/local)
-// non-local provider, else the first usable local one. It lets the CLI fall back
-// to an already-configured login when the active provider happens to lack a
-// credential, instead of re-running onboarding every launch.
+// onboarding: the first usable (inline credential, stored OAuth login, or
+// no-auth/local) non-local provider, else the first usable local one. It lets
+// the CLI fall back to an already-configured login when the active provider
+// happens to lack a credential, instead of re-running onboarding every launch.
 func firstUsableProvider(providers []config.ProviderProfile) (config.ProviderProfile, bool) {
+	logins := oauthLoggedInProviders()
 	var localFallback config.ProviderProfile
 	haveLocal := false
 	for _, profile := range providers {
@@ -371,7 +374,11 @@ func firstUsableProvider(providers []config.ProviderProfile) (config.ProviderPro
 				continue
 			}
 		}
-		if _, missing := setupMissingCredentialEnv(profile); missing {
+		// A stored OAuth login (e.g. `zero auth login xai`) is a credential too, even
+		// when the profile has no inline key / env var — mirrors setupRequired and
+		// usableSavedProviders so this fallback doesn't force onboarding for a
+		// provider the user is already authenticated with.
+		if _, missing := setupMissingCredentialEnv(profile); missing && !providerHasOAuthLogin(profile, logins) {
 			continue
 		}
 		if providerProfileIsLocal(profile) {
@@ -496,41 +503,14 @@ func setupTryThisExample(profile config.ProviderProfile) string {
 	return example
 }
 
+// setupMissingCredentialEnv reports the environment variable a saved profile
+// is expected to read an API key from, and whether that expectation is
+// unmet. It delegates to config.ProviderProfile.MissingCredentialEnv, the
+// single source of truth shared with the TUI's provider status/wizard
+// surfaces and the CLI's `providers check` readiness gate, so all three never
+// disagree about whether a saved provider is missing a credential.
 func setupMissingCredentialEnv(profile config.ProviderProfile) (string, bool) {
-	if providerProfileHasCredential(profile) {
-		return "", false
-	}
-	if catalogID := strings.TrimSpace(profile.CatalogID); catalogID != "" {
-		descriptor, err := providercatalog.Require(catalogID)
-		if err != nil || !descriptor.RequiresAuth {
-			return "", false
-		}
-		return firstNonEmptyCLI(profile.APIKeyEnv, setupProviderEnvVar(descriptor)), true
-	}
-
-	switch normalizedSetupProviderKind(profile) {
-	case config.ProviderKindOpenAI, config.ProviderKindOpenAICompatible:
-		return firstNonEmptyCLI(profile.APIKeyEnv, "OPENAI_API_KEY"), true
-	case config.ProviderKindAnthropic, config.ProviderKindAnthropicCompat:
-		return firstNonEmptyCLI(profile.APIKeyEnv, "ANTHROPIC_API_KEY"), true
-	case config.ProviderKindGoogle:
-		return firstNonEmptyCLI(profile.APIKeyEnv, "GEMINI_API_KEY"), true
-	default:
-		if strings.TrimSpace(profile.APIKeyEnv) != "" {
-			return strings.TrimSpace(profile.APIKeyEnv), true
-		}
-		return "", false
-	}
-}
-
-func normalizedSetupProviderKind(profile config.ProviderProfile) config.ProviderKind {
-	if kind := strings.TrimSpace(string(profile.ProviderKind)); kind != "" {
-		return config.ProviderKind(strings.ToLower(kind))
-	}
-	if provider := strings.TrimSpace(profile.Provider); provider != "" {
-		return config.ProviderKind(strings.ToLower(provider))
-	}
-	return ""
+	return profile.MissingCredentialEnv()
 }
 
 func setupCheckCommand(name string) string {

internal/cli/setup_fallback_test.go

@@ -2,11 +2,14 @@ package cli
 
 import (
 	"testing"
+	"time"
 
 	"github.com/Gitlawb/zero/internal/config"
+	"github.com/Gitlawb/zero/internal/oauth"
 )
 
 func TestFirstUsableProviderPrefersRemoteKeyed(t *testing.T) {
+	withAuthStore(t)
 	providers := []config.ProviderProfile{
 		{Name: "ollama", CatalogID: "ollama", BaseURL: "http://localhost:11434/v1", APIKey: "k"},      // usable but local
 		{Name: "moonshot", CatalogID: "moonshot", BaseURL: "https://api.moonshot.ai/v1", APIKey: "k"}, // usable, remote
@@ -19,6 +22,7 @@ func TestFirstUsableProviderPrefersRemoteKeyed(t *testing.T) {
 }
 
 func TestFirstUsableProviderFallsBackToLocal(t *testing.T) {
+	withAuthStore(t)
 	providers := []config.ProviderProfile{
 		{Name: "xai", CatalogID: "xai", APIKeyEnv: "XAI_API_KEY"},                                // not usable
 		{Name: "ollama", CatalogID: "ollama", BaseURL: "http://localhost:11434/v1", APIKey: "k"}, // local, usable
@@ -30,6 +34,7 @@ func TestFirstUsableProviderFallsBackToLocal(t *testing.T) {
 }
 
 func TestFirstUsableProviderNoneUsable(t *testing.T) {
+	withAuthStore(t)
 	providers := []config.ProviderProfile{
 		{Name: "xai", CatalogID: "xai", APIKeyEnv: "XAI_API_KEY"},
 		{Name: "openai", CatalogID: "openai", APIKeyEnv: "OPENAI_API_KEY"},
@@ -42,6 +47,10 @@ func TestFirstUsableProviderNoneUsable(t *testing.T) {
 // A keyless local proxy (chatgpt-proxy, RequiresAuth=false) is usable without a
 // credential, so it can serve as a fallback rather than forcing onboarding.
 func TestFirstUsableProviderAcceptsKeylessLocalProxy(t *testing.T) {
+	// Isolate the OAuth token store: on a developer machine with a real xai
+	// login, the env-only xai profile would count as usable and win over the
+	// local proxy this test is about.
+	withAuthStore(t)
 	providers := []config.ProviderProfile{
 		{Name: "xai", CatalogID: "xai", APIKeyEnv: "XAI_API_KEY"},
 		{Name: "chatgpt", CatalogID: "chatgpt-proxy", BaseURL: "http://localhost:10531/v1"},
@@ -56,6 +65,7 @@ func TestFirstUsableProviderAcceptsKeylessLocalProxy(t *testing.T) {
 // BaseURL has no endpoint, so it must be skipped rather than selected as a
 // fallback that fails at first use. A stale CatalogID with a BaseURL still works.
 func TestFirstUsableProviderSkipsUnresolvableCatalogWithoutBaseURL(t *testing.T) {
+	withAuthStore(t)
 	providers := []config.ProviderProfile{
 		{Name: "ghost", CatalogID: "no-such-catalog-entry", APIKey: "k"}, // unusable: no endpoint
 		{Name: "custom", CatalogID: "no-such-catalog-entry", BaseURL: "https://api.custom.test/v1", APIKey: "k"},
@@ -66,6 +76,29 @@ func TestFirstUsableProviderSkipsUnresolvableCatalogWithoutBaseURL(t *testing.T)
 	}
 }
 
+// An OAuth-only provider (no inline key, no env var) must be selectable as a
+// fallback, matching setupRequired/usableSavedProviders — otherwise a fully
+// authenticated user gets forced back into onboarding when activeProvider
+// goes stale.
+func TestFirstUsableProviderRecognizesOAuthLogin(t *testing.T) {
+	withAuthStore(t)
+	store, err := oauth.NewStore(oauth.StoreOptions{})
+	if err != nil {
+		t.Fatalf("NewStore: %v", err)
+	}
+	if err := store.Save(oauth.ProviderKey("xai"), oauth.Token{AccessToken: "tok", ExpiresAt: time.Now().Add(time.Hour)}); err != nil {
+		t.Fatalf("seed token: %v", err)
+	}
+
+	providers := []config.ProviderProfile{
+		{Name: "xai", CatalogID: "xai", APIKeyEnv: "XAI_API_KEY"}, // no inline key/env, but logged in via OAuth
+	}
+	got, ok := firstUsableProvider(providers)
+	if !ok || got.Name != "xai" {
+		t.Fatalf("want OAuth-logged-in provider (xai), got %q ok=%v", got.Name, ok)
+	}
+}
+
 func TestProviderProfileIsLocal(t *testing.T) {
 	cases := []struct {
 		name    string
@@ -89,3 +122,32 @@ func TestProviderProfileIsLocal(t *testing.T) {
 		})
 	}
 }
+
+// TestFirstUsableProviderAcceptsOAuthLoginProfile: a keyless catalog profile
+// whose credential is a stored OAuth login (the shape the login flows persist)
+// must be usable during active-pointer recovery — the same rule setupRequired
+// and usableSavedProviders apply — instead of falling through to onboarding.
+func TestFirstUsableProviderAcceptsOAuthLoginProfile(t *testing.T) {
+	withAuthStore(t)
+	providers := []config.ProviderProfile{
+		{Name: "chatgpt", CatalogID: "chatgpt", BaseURL: "https://chatgpt.com/backend-api/codex", Model: "gpt-5.5"},
+	}
+
+	// No login stored: still not usable.
+	if got, ok := firstUsableProvider(providers); ok {
+		t.Fatalf("keyless profile without a login must not be usable, got %q", got.Name)
+	}
+
+	store, err := oauth.NewStore(oauth.StoreOptions{})
+	if err != nil {
+		t.Fatalf("oauth store: %v", err)
+	}
+	if err := store.Save(oauth.ProviderKey("chatgpt"), oauth.Token{AccessToken: "bearer-123"}); err != nil {
+		t.Fatalf("save token: %v", err)
+	}
+
+	got, ok := firstUsableProvider(providers)
+	if !ok || got.Name != "chatgpt" {
+		t.Fatalf("want OAuth-login profile to be usable, got %q ok=%v", got.Name, ok)
+	}
+}

internal/cli/setup_test.go

@@ -64,6 +64,54 @@ func TestSetupMissingCredentialEnv(t *testing.T) {
 			},
 			want: false,
 		},
+		{
+			// Regression for issue #555: a custom OpenAI-compatible profile saved
+			// with no credential (e.g. a local llama.cpp server with no auth) must
+			// not be reported as missing one, or it gets filtered out of /model on
+			// the next run even though it was configured exactly as intended.
+			name: "custom openai compatible with no credential configured",
+			profile: config.ProviderProfile{
+				Name:      "local-llama",
+				CatalogID: "custom-openai-compatible",
+				BaseURL:   "http://192.168.1.50:8080/v1",
+			},
+			want: false,
+		},
+		{
+			name: "custom openai compatible with explicit api key env",
+			profile: config.ProviderProfile{
+				Name:      "local-llama",
+				CatalogID: "custom-openai-compatible",
+				BaseURL:   "http://192.168.1.50:8080/v1",
+				APIKeyEnv: "LLAMA_CPP_API_KEY",
+			},
+			wantEnv: "LLAMA_CPP_API_KEY",
+			want:    true,
+		},
+		{
+			// Self-heal regression: profiles saved by the pre-fix wizard were
+			// stamped with the catalog's own guessed default (OPENAI_API_KEY)
+			// even when the endpoint needed no auth. That stale value must be
+			// treated the same as unset so already-broken saved profiles start
+			// working again without a config.json rewrite.
+			name: "custom openai compatible with stale legacy default env",
+			profile: config.ProviderProfile{
+				Name:      "local-llama",
+				CatalogID: "custom-openai-compatible",
+				BaseURL:   "http://192.168.1.50:8080/v1",
+				APIKeyEnv: "OPENAI_API_KEY",
+			},
+			want: false,
+		},
+		{
+			name: "custom anthropic compatible with no credential configured",
+			profile: config.ProviderProfile{
+				Name:      "local-proxy",
+				CatalogID: "custom-anthropic-compatible",
+				BaseURL:   "http://localhost:9000/anthropic",
+			},
+			want: false,
+		},
 	}
 
 	for _, tt := range tests {

internal/config/credentials.go

@@ -8,6 +8,7 @@ import (
 	"strings"
 
 	"github.com/Gitlawb/zero/internal/credstore"
+	"github.com/Gitlawb/zero/internal/providercatalog"
 )
 
 // ProviderKeyStoreAt opens the encrypted credential store whose file backend lives
@@ -168,6 +169,86 @@ func (profile ProviderProfile) HasConfiguredCredential() bool {
 		strings.TrimSpace(profile.AuthHeaderValue) != ""
 }
 
+// MissingCredentialEnv reports the environment variable this profile is
+// expected to read an API key from, and whether that expectation is
+// currently unmet. It is the single source of truth for "does this saved
+// provider need a credential it doesn't have" — the CLI (`providers check`,
+// `usableSavedProviders`) and TUI (`/providers` status, provider wizard
+// summary) surfaces all delegate here so they never disagree about a
+// profile's status.
+//
+// For the catalog's two "bring your own endpoint" descriptors
+// (custom-openai-compatible, custom-anthropic-compatible), RequiresAuth is
+// just a wizard template default, not a fact about the user's actual
+// endpoint: a custom target may need no auth at all. So for those two only,
+// a credential is expected exclusively when this profile carries its own
+// explicit APIKeyEnv that differs from the catalog's guessed default — a
+// value matching that default is indistinguishable from the wizard's old
+// auto-stamp bug (issue #555) and is treated the same as unset, which also
+// self-heals profiles saved before that bug was fixed.
+func (profile ProviderProfile) MissingCredentialEnv() (string, bool) {
+	if profile.HasConfiguredCredential() {
+		return "", false
+	}
+	if catalogID := strings.TrimSpace(profile.CatalogID); catalogID != "" {
+		descriptor, err := providercatalog.Require(catalogID)
+		if err != nil {
+			return "", false
+		}
+		defaultEnvVar := firstNonEmptyTrimmed(descriptor.AuthEnvVars...)
+		if descriptor.Custom {
+			envVar := strings.TrimSpace(profile.APIKeyEnv)
+			if envVar == "" || envVar == defaultEnvVar {
+				return "", false
+			}
+			return envVar, true
+		}
+		if !descriptor.RequiresAuth {
+			return "", false
+		}
+		if envVar := strings.TrimSpace(profile.APIKeyEnv); envVar != "" {
+			return envVar, true
+		}
+		return defaultEnvVar, true
+	}
+
+	switch profile.normalizedProviderKind() {
+	case ProviderKindOpenAI, ProviderKindOpenAICompatible:
+		return firstNonEmptyTrimmed(profile.APIKeyEnv, "OPENAI_API_KEY"), true
+	case ProviderKindAnthropic, ProviderKindAnthropicCompat:
+		return firstNonEmptyTrimmed(profile.APIKeyEnv, "ANTHROPIC_API_KEY"), true
+	case ProviderKindGoogle:
+		return firstNonEmptyTrimmed(profile.APIKeyEnv, "GEMINI_API_KEY"), true
+	default:
+		if envVar := strings.TrimSpace(profile.APIKeyEnv); envVar != "" {
+			return envVar, true
+		}
+		return "", false
+	}
+}
+
+// normalizedProviderKind resolves this profile's kind, falling back to the
+// legacy Provider string field (lowercased) when ProviderKind is unset —
+// matching how the resolver (resolver.go) treats the two fields as synonyms.
+func (profile ProviderProfile) normalizedProviderKind() ProviderKind {
+	if kind := strings.TrimSpace(string(profile.ProviderKind)); kind != "" {
+		return ProviderKind(strings.ToLower(kind))
+	}
+	if provider := strings.TrimSpace(profile.Provider); provider != "" {
+		return ProviderKind(strings.ToLower(provider))
+	}
+	return ""
+}
+
+func firstNonEmptyTrimmed(values ...string) string {
+	for _, value := range values {
+		if trimmed := strings.TrimSpace(value); trimmed != "" {
+			return trimmed
+		}
+	}
+	return ""
+}
+
 // OAuthLoginCandidates returns the login names to try, in order, when resolving
 // this profile's OAuth token — used by the runtime bearer resolver, the Codex
 // account-header resolver, and the onboarding presence check so all three agree.

internal/config/credentials_test.go

@@ -238,3 +238,82 @@ func TestOAuthLoginCandidates(t *testing.T) {
 		})
 	}
 }
+
+func TestProviderProfileMissingCredentialEnv(t *testing.T) {
+	cases := []struct {
+		name    string
+		profile ProviderProfile
+		wantEnv string
+		want    bool
+	}{
+		{
+			name:    "catalog provider requiring auth",
+			profile: ProviderProfile{Name: "groq", CatalogID: "groq"},
+			wantEnv: "GROQ_API_KEY",
+			want:    true,
+		},
+		{
+			name:    "local catalog provider",
+			profile: ProviderProfile{Name: "local", CatalogID: "ollama"},
+			want:    false,
+		},
+		{
+			name:    "credential resolved via inline key",
+			profile: ProviderProfile{Name: "openai", ProviderKind: ProviderKindOpenAI, APIKey: "sk-test"},
+			want:    false,
+		},
+		{
+			// issue #555: a custom endpoint left with no credential means "no
+			// auth needed" (e.g. a local llama.cpp server), not "missing".
+			name: "custom openai compatible with no credential configured",
+			profile: ProviderProfile{
+				Name:      "local-llama",
+				CatalogID: "custom-openai-compatible",
+				BaseURL:   "http://192.168.1.50:8080/v1",
+			},
+			want: false,
+		},
+		{
+			name: "custom openai compatible with explicit non-default api key env",
+			profile: ProviderProfile{
+				Name:      "local-llama",
+				CatalogID: "custom-openai-compatible",
+				APIKeyEnv: "LLAMA_CPP_API_KEY",
+			},
+			wantEnv: "LLAMA_CPP_API_KEY",
+			want:    true,
+		},
+		{
+			// Self-heal: a profile stamped by the pre-fix wizard with the
+			// catalog's own guessed default is indistinguishable from that bug
+			// and must not stay filtered out after upgrading.
+			name: "custom openai compatible with stale legacy default env",
+			profile: ProviderProfile{
+				Name:      "local-llama",
+				CatalogID: "custom-openai-compatible",
+				APIKeyEnv: "OPENAI_API_KEY",
+			},
+			want: false,
+		},
+		{
+			name:    "openai compatible without catalog falls back to provider kind",
+			profile: ProviderProfile{Name: "custom", ProviderKind: ProviderKindOpenAICompatible},
+			wantEnv: "OPENAI_API_KEY",
+			want:    true,
+		},
+		{
+			name:    "legacy Provider string field fallback",
+			profile: ProviderProfile{Name: "legacy", Provider: "anthropic"},
+			wantEnv: "ANTHROPIC_API_KEY",
+			want:    true,
+		},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			gotEnv, got := c.profile.MissingCredentialEnv()
+			if got != c.want || gotEnv != c.wantEnv {
+				t.Fatalf("MissingCredentialEnv() = (%q, %v), want (%q, %v)", gotEnv, got, c.wantEnv, c.want)
+			}
+		})
+	}
+}

internal/config/mcp_defaults.go

@@ -1,6 +1,9 @@
 package config
 
-import "strings"
+import (
+	"reflect"
+	"strings"
+)
 
 // DefaultMCPServers returns the MCP servers Zero ships ENABLED by default so web
 // search and scraping work out of the box with no setup and no API key. They are
@@ -29,3 +32,29 @@ func IsDefaultMCPServer(name string) bool {
 	_, ok := DefaultMCPServers()[strings.TrimSpace(name)]
 	return ok
 }
+
+// IsUnconfiguredDefault reports whether server is one of Zero's built-in
+// defaults that the user never wrote an entry for in their config — i.e. it is
+// running with whatever Zero ships (e.g. keyless Firecrawl, no credentials).
+//
+// Both conditions below must hold:
+//   - !server.configured: the user's JSON never declared an object for this
+//     server key at all (set by MCPServerConfig.UnmarshalJSON only when it
+//     actually ran for this key). Any explicit action — including a
+//     disable/enable toggle like `zero mcp enable firecrawl` that leaves the
+//     resolved value unchanged — sets configured, so it always counts as
+//     user-configured, even though the value comparison below could not tell
+//     the difference on its own.
+//   - reflect.DeepEqual(def, server): the value still matches the default.
+//     This is the fallback for callers that construct MCPServerConfig
+//     directly rather than through the JSON/merge pipeline (server.configured
+//     is then always false) — without it, any hand-built config with
+//     different field values would be misreported as unconfigured.
+//
+// Callers use this to tell "server we turned on for the user" apart from
+// "server the user configured themselves," e.g. to avoid warning loudly when
+// an out-of-the-box default that was never given credentials fails to connect.
+func IsUnconfiguredDefault(name string, server MCPServerConfig) bool {
+	def, ok := DefaultMCPServers()[strings.TrimSpace(name)]
+	return ok && !server.configured && reflect.DeepEqual(def, server)
+}

internal/config/mcp_defaults_test.go

@@ -49,6 +49,69 @@ func TestResolveMCPUserCanDisableDefault(t *testing.T) {
 	}
 }
 
+func TestIsUnconfiguredDefault(t *testing.T) {
+	if !IsUnconfiguredDefault("firecrawl", DefaultMCPServers()["firecrawl"]) {
+		t.Fatal("an untouched firecrawl default should be reported as unconfigured")
+	}
+	if IsUnconfiguredDefault("firecrawl", MCPServerConfig{Type: "http", URL: "http://localhost:3002/mcp"}) {
+		t.Fatal("a server overriding the default URL is no longer unconfigured")
+	}
+	if IsUnconfiguredDefault("firecrawl", MCPServerConfig{Type: "http", URL: "https://mcp.firecrawl.dev/v2/mcp", Auth: "bearer"}) {
+		t.Fatal("a server with credentials added is no longer unconfigured")
+	}
+	if IsUnconfiguredDefault("not-a-default", MCPServerConfig{}) {
+		t.Fatal("a server with no matching default can never be unconfigured-default")
+	}
+}
+
+func TestResolveMCPExplicitReenableIsNotUnconfiguredDefault(t *testing.T) {
+	// `zero mcp enable firecrawl` after a prior disable writes {"disabled":false}
+	// explicitly. The resolved value is identical to the untouched default (both
+	// enabled, no credentials), but the user DID take an explicit action here, so
+	// IsUnconfiguredDefault must not treat it as untouched (issue #563 review).
+	path := filepath.Join(t.TempDir(), "config.json")
+	if err := os.WriteFile(path, []byte(`{"mcp":{"servers":{"firecrawl":{"disabled":false}}}}`), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	cfg, err := ResolveMCP(ResolveOptions{UserConfigPath: path})
+	if err != nil {
+		t.Fatalf("ResolveMCP: %v", err)
+	}
+	firecrawl := cfg.Servers["firecrawl"]
+	if firecrawl.Disabled {
+		t.Fatalf("explicit re-enable should leave the server enabled: %#v", firecrawl)
+	}
+	if IsUnconfiguredDefault("firecrawl", firecrawl) {
+		t.Fatal("an explicit enable/disable toggle must count as user-configured, even though the resolved value matches the default")
+	}
+}
+
+func TestResolveMCPExplicitRedeclareOfDefaultValuesIsNotUnconfiguredDefault(t *testing.T) {
+	// A user who copies firecrawl's exact default type/url into their config
+	// (e.g. from an example file, planning to add credentials later) produces a
+	// resolved value byte-identical to DefaultMCPServers()["firecrawl"] — the
+	// same trap TestResolveMCPExplicitReenableIsNotUnconfiguredDefault covers for
+	// the disabled toggle. IsUnconfiguredDefault must still treat this as
+	// user-configured because the user's JSON declared an entry for it, even
+	// though a plain resolved-value comparison could not tell the difference.
+	path := filepath.Join(t.TempDir(), "config.json")
+	if err := os.WriteFile(path, []byte(`{"mcp":{"servers":{"firecrawl":{"type":"http","url":"https://mcp.firecrawl.dev/v2/mcp"}}}}`), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	cfg, err := ResolveMCP(ResolveOptions{UserConfigPath: path})
+	if err != nil {
+		t.Fatalf("ResolveMCP: %v", err)
+	}
+	firecrawl := cfg.Servers["firecrawl"]
+	want := DefaultMCPServers()["firecrawl"]
+	if firecrawl.Type != want.Type || firecrawl.URL != want.URL || firecrawl.Disabled != want.Disabled {
+		t.Fatalf("expected the resolved value to match the default's fields exactly: %#v", firecrawl)
+	}
+	if IsUnconfiguredDefault("firecrawl", firecrawl) {
+		t.Fatal("redeclaring the default's exact values is still an explicit user configuration, not an untouched default")
+	}
+}
+
 func TestResolveMCPUserCanOverrideDefaultURLKeepingOtherFields(t *testing.T) {
 	path := filepath.Join(t.TempDir(), "config.json")
 	// Point firecrawl at a self-hosted instance; the default's Type must survive.

internal/config/resolver.go

@@ -127,6 +127,9 @@ func Resolve(options ResolveOptions) (ResolvedConfig, error) {
 			return ResolvedConfig{}, fmt.Errorf("invalid notify.focusMode %q: expected unfocused, always, or focused", focusMode)
 		}
 	}
+	if err := validateSTTConfig(cfg.STT); err != nil {
+		return ResolvedConfig{}, err
+	}
 
 	providers, active, err := normalizeProviders(cfg.Providers, cfg.ActiveProvider, options.Env)
 	if err != nil {
@@ -150,6 +153,7 @@ func Resolve(options ResolveOptions) (ResolvedConfig, error) {
 		Preferences:    cfg.Preferences,
 		KeyBindings:    cfg.KeyBindings,
 		LocalControl:   cfg.LocalControl,
+		STT:            cfg.STT,
 	}, nil
 }
 
@@ -223,6 +227,9 @@ func mergeConfig(dst *FileConfig, src FileConfig) {
 	if src.Preferences.FavoriteModels != nil {
 		dst.Preferences.FavoriteModels = normalizeFavoriteModels(src.Preferences.FavoriteModels)
 	}
+	if src.Preferences.RecentModels != nil {
+		dst.Preferences.RecentModels = NormalizeRecentModels(src.Preferences.RecentModels)
+	}
 	if src.Preferences.Recaps != nil {
 		dst.Preferences.Recaps = src.Preferences.Recaps
 	}
@@ -231,6 +238,7 @@ func mergeConfig(dst *FileConfig, src FileConfig) {
 	}
 	mergeLocalControlConfig(&dst.LocalControl, src.LocalControl)
 	mergeKeyBindings(&dst.KeyBindings, src.KeyBindings)
+	mergeSTTConfig(&dst.STT, src.STT)
 }
 
 func mergeProjectConfig(dst *FileConfig, src FileConfig) error {
@@ -681,6 +689,7 @@ func applyOverrides(cfg *FileConfig, overrides Overrides) {
 	}
 	mergeLocalControlConfig(&cfg.LocalControl, overrides.LocalControl)
 	mergeKeyBindings(&cfg.KeyBindings, overrides.KeyBindings)
+	mergeSTTConfig(&cfg.STT, overrides.STT)
 	for _, provider := range overrides.Providers {
 		mergeProvider(cfg, provider)
 	}
@@ -734,6 +743,91 @@ func mergeKeyBindings(dst *KeyBindingsConfig, src KeyBindingsConfig) {
 	}
 }
 
+// mergeSTTConfig overlays any set field of src onto dst. Each field carries its
+// own "unset" sentinel (empty string, 0, or nil *bool), matching how the other
+// section mergers detect intent.
+func mergeSTTConfig(dst *STTConfig, src STTConfig) {
+	if src.Provider != "" {
+		dst.Provider = src.Provider
+	}
+	if src.StreamProvider != "" {
+		dst.StreamProvider = src.StreamProvider
+	}
+	if src.Streaming != nil {
+		dst.Streaming = src.Streaming
+	}
+	if src.Model != "" {
+		dst.Model = src.Model
+	}
+	if src.StreamModel != "" {
+		dst.StreamModel = src.StreamModel
+	}
+	if src.LocalModelPath != "" {
+		dst.LocalModelPath = src.LocalModelPath
+	}
+	if src.LocalBinary != "" {
+		dst.LocalBinary = src.LocalBinary
+	}
+	if src.LocalServerBinary != "" {
+		dst.LocalServerBinary = src.LocalServerBinary
+	}
+	if src.LocalServerPort != 0 {
+		dst.LocalServerPort = src.LocalServerPort
+	}
+	if src.EngineVersion != "" {
+		dst.EngineVersion = src.EngineVersion
+	}
+	if src.NumThreads != 0 {
+		dst.NumThreads = src.NumThreads
+	}
+	if src.Language != "" {
+		dst.Language = src.Language
+	}
+	if src.MaxDurationSeconds != 0 {
+		dst.MaxDurationSeconds = src.MaxDurationSeconds
+	}
+	if src.SilenceAutoStop != nil {
+		dst.SilenceAutoStop = src.SilenceAutoStop
+	}
+	if src.AutoSubmit != nil {
+		dst.AutoSubmit = src.AutoSubmit
+	}
+	if src.WindowsAudioDevice != "" {
+		dst.WindowsAudioDevice = src.WindowsAudioDevice
+	}
+}
+
+// validateSTTConfig rejects unknown provider/streamProvider values and a
+// negative maxDurationSeconds at load time — a clear startup error naming the
+// bad value and the valid options, never a silent fallback the user did not ask
+// for (§11a).
+func validateSTTConfig(cfg STTConfig) error {
+	if cfg.Provider != "" {
+		switch cfg.Provider {
+		case STTProviderLocal, STTProviderGroq, STTProviderOpenAI:
+		default:
+			return fmt.Errorf("invalid stt.provider %q: expected local, groq, or openai", cfg.Provider)
+		}
+	}
+	if cfg.StreamProvider != "" {
+		switch cfg.StreamProvider {
+		case STTProviderLocal, STTProviderDeepgram, STTProviderOpenAI:
+		default:
+			return fmt.Errorf("invalid stt.streamProvider %q: expected local, deepgram, or openai", cfg.StreamProvider)
+		}
+	}
+	if cfg.MaxDurationSeconds < 0 {
+		return fmt.Errorf("invalid stt.maxDurationSeconds %d: must be >= 0 (0 uses the default)", cfg.MaxDurationSeconds)
+	}
+	if cfg.NumThreads < 0 {
+		return fmt.Errorf("invalid stt.numThreads %d: must be >= 0 (0 uses the engine default)", cfg.NumThreads)
+	}
+	if cfg.LocalServerPort < 0 || cfg.LocalServerPort > 65535 {
+		return fmt.Errorf("invalid stt.localServerPort %d: must be between 1 and 65535 (0 uses the default)", cfg.LocalServerPort)
+	}
+	return nil
+}
+
 func mergeMCPConfig(dst *MCPConfig, src MCPConfig) {
 	if len(src.Servers) == 0 {
 		return
@@ -774,6 +868,9 @@ func mergeMCPServer(base MCPServerConfig, next MCPServerConfig) MCPServerConfig
 	if next.disabledSet || next.Disabled {
 		base.Disabled = next.Disabled
 	}
+	if next.configured {
+		base.configured = true
+	}
 	return base
 }
 

internal/config/resolver_test.go

@@ -127,6 +127,79 @@ func TestResolveLoadsFavoriteModelsFromUserConfigOnly(t *testing.T) {
 	}
 }
 
+func TestResolveLoadsRecentModelsFromUserConfigOnly(t *testing.T) {
+	userPath := writeConfig(t, `{
+		"activeProvider": "user",
+		"providers": [{
+			"name": "user",
+			"provider": "openai",
+			"apiKey": "sk-user",
+			"model": "gpt-user"
+		}],
+		"preferences": {
+			"recentModels": [
+				{"provider": "openrouter", "model": " google/gemini-2.5-pro "},
+				{"provider": "openrouter", "model": "minimax/minimax-m2.1"}
+			]
+		}
+	}`)
+	projectPath := writeConfig(t, `{
+		"preferences": {
+			"recentModels": [{"provider": "project", "model": "project-model"}]
+		}
+	}`)
+
+	resolved, err := Resolve(ResolveOptions{
+		UserConfigPath:    userPath,
+		ProjectConfigPath: projectPath,
+		Env:               map[string]string{},
+	})
+	if err != nil {
+		t.Fatalf("Resolve() error = %v", err)
+	}
+
+	want := []RecentModelEntry{
+		{Provider: "openrouter", Model: "google/gemini-2.5-pro"},
+		{Provider: "openrouter", Model: "minimax/minimax-m2.1"},
+	}
+	if !reflect.DeepEqual(resolved.Preferences.RecentModels, want) {
+		t.Fatalf("RecentModels = %#v, want %#v", resolved.Preferences.RecentModels, want)
+	}
+}
+
+// recentModels must never be merged from project config (same posture as
+// favoriteModels): a project setting it with no corresponding user setting
+// should leave the resolved value empty, not pick up the project's list.
+func TestResolveIgnoresProjectOnlyRecentModels(t *testing.T) {
+	userPath := writeConfig(t, `{
+		"activeProvider": "user",
+		"providers": [{
+			"name": "user",
+			"provider": "openai",
+			"apiKey": "sk-user",
+			"model": "gpt-user"
+		}]
+	}`)
+	projectPath := writeConfig(t, `{
+		"preferences": {
+			"recentModels": [{"provider": "project", "model": "project-model"}]
+		}
+	}`)
+
+	resolved, err := Resolve(ResolveOptions{
+		UserConfigPath:    userPath,
+		ProjectConfigPath: projectPath,
+		Env:               map[string]string{},
+	})
+	if err != nil {
+		t.Fatalf("Resolve() error = %v", err)
+	}
+
+	if len(resolved.Preferences.RecentModels) != 0 {
+		t.Fatalf("RecentModels = %#v, want empty (project-only recentModels must not be merged)", resolved.Preferences.RecentModels)
+	}
+}
+
 func TestResolveLoadsProviderCatalogSnakeAndCamelJSONFields(t *testing.T) {
 	path := writeConfig(t, `{
 		"activeProvider": "snake",

internal/config/stt_test.go

@@ -0,0 +1,139 @@
+package config
+
+import (
+	"os"
+	"strings"
+	"testing"
+)
+
+func TestSetSTTLocalEngineResetsStreamProvider(t *testing.T) {
+	dir := t.TempDir()
+	path := dir + "/config.json"
+	// Pre-seed a cloud streaming provider — the situation the fix guards against.
+	if err := os.WriteFile(path, []byte(`{"stt":{"streamProvider":"deepgram"}}`), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	cfg, err := SetSTTLocalEngine(path, "sherpa-onnx-offline", "sherpa-onnx-online-websocket-server", "/models/kroko", true)
+	if err != nil {
+		t.Fatalf("SetSTTLocalEngine: %v", err)
+	}
+	// Switching to a local model must point BOTH pipelines at the local engine, or
+	// the leftover cloud streamProvider keeps the live transcript on the cloud.
+	if cfg.STT.Provider != STTProviderLocal || cfg.STT.StreamProvider != STTProviderLocal {
+		t.Errorf("both providers should be local, got provider=%q streamProvider=%q", cfg.STT.Provider, cfg.STT.StreamProvider)
+	}
+}
+
+func TestValidateSTTConfigRejectsUnknownProvider(t *testing.T) {
+	_, issues := ValidateBytes([]byte(`{"stt":{"provider":"assemblyai"}}`))
+	if len(issues) == 0 {
+		t.Fatal("expected an issue for unknown stt.provider")
+	}
+	if !strings.Contains(issues[0].Message, "assemblyai") || !strings.Contains(issues[0].Message, "local, groq, or openai") {
+		t.Errorf("issue message = %q, want it to name the bad value and valid options", issues[0].Message)
+	}
+}
+
+func TestValidateSTTConfigRejectsUnknownStreamProvider(t *testing.T) {
+	_, issues := ValidateBytes([]byte(`{"stt":{"streamProvider":"groq"}}`))
+	if len(issues) == 0 {
+		t.Fatal("expected an issue: groq has no streaming product, not a valid streamProvider")
+	}
+	if !strings.Contains(issues[0].Message, "deepgram") {
+		t.Errorf("issue message = %q", issues[0].Message)
+	}
+}
+
+func TestValidateSTTConfigAcceptsValid(t *testing.T) {
+	_, issues := ValidateBytes([]byte(`{"stt":{"provider":"groq","streamProvider":"deepgram","maxDurationSeconds":120}}`))
+	if len(issues) != 0 {
+		t.Fatalf("unexpected issues: %+v", issues)
+	}
+}
+
+func TestValidateSTTConfigRejectsNegativeDuration(t *testing.T) {
+	_, issues := ValidateBytes([]byte(`{"stt":{"maxDurationSeconds":-5}}`))
+	if len(issues) == 0 {
+		t.Fatal("expected an issue for negative maxDurationSeconds")
+	}
+}
+
+func TestSTTConfigDefaults(t *testing.T) {
+	cfg := STTConfig{}
+	if cfg.STTProvider() != STTProviderLocal {
+		t.Errorf("default provider = %q, want local", cfg.STTProvider())
+	}
+	if cfg.STTStreamProvider() != STTProviderLocal {
+		t.Errorf("default streamProvider = %q, want local", cfg.STTStreamProvider())
+	}
+	if !cfg.StreamingEnabled() {
+		t.Error("streaming should default on")
+	}
+	if !cfg.SilenceAutoStopEnabled() {
+		t.Error("silence auto-stop should default on")
+	}
+	if cfg.AutoSubmitEnabled() {
+		t.Error("auto-submit should default off (insert-for-review is the safety net)")
+	}
+	if !cfg.Empty() {
+		t.Error("zero-value STTConfig should be Empty")
+	}
+}
+
+func TestSTTConfigTriStateBools(t *testing.T) {
+	cfg, issues := ValidateBytes([]byte(`{"stt":{"autoSubmit":true,"streaming":false,"silenceAutoStop":false}}`))
+	if len(issues) != 0 {
+		t.Fatalf("unexpected issues: %+v", issues)
+	}
+	if !cfg.STT.AutoSubmitEnabled() {
+		t.Error("autoSubmit:true should be enabled")
+	}
+	if cfg.STT.StreamingEnabled() {
+		t.Error("streaming:false should be disabled")
+	}
+	if cfg.STT.SilenceAutoStopEnabled() {
+		t.Error("silenceAutoStop:false should be disabled")
+	}
+}
+
+func TestSTTConfigRoundTripsThroughMarshal(t *testing.T) {
+	cfg, _ := ValidateBytes([]byte(`{"stt":{"provider":"groq","model":"whisper-large-v3-turbo","localServerPort":6007}}`))
+	data, err := cfg.MarshalJSON()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.Contains(string(data), `"stt"`) {
+		t.Errorf("marshaled config dropped stt section: %s", data)
+	}
+	reparsed, issues := ValidateBytes(data)
+	if len(issues) != 0 {
+		t.Fatalf("re-parse issues: %+v", issues)
+	}
+	if reparsed.STT.Provider != STTProviderGroq || reparsed.STT.Model != "whisper-large-v3-turbo" || reparsed.STT.LocalServerPort != 6007 {
+		t.Errorf("round-trip lost fields: %+v", reparsed.STT)
+	}
+}
+
+func TestSetSTTModelPersists(t *testing.T) {
+	dir := t.TempDir()
+	path := dir + "/config.json"
+	// Cloud provider stores under stt.model.
+	if _, err := SetSTTModel(path, STTProviderGroq, "whisper-large-v3-turbo"); err != nil {
+		t.Fatalf("SetSTTModel: %v", err)
+	}
+	cfg, issues := ValidateFile(path)
+	if len(issues) != 0 {
+		t.Fatalf("issues: %+v", issues)
+	}
+	if cfg.STT.Provider != STTProviderGroq || cfg.STT.Model != "whisper-large-v3-turbo" {
+		t.Errorf("persisted STT = %+v", cfg.STT)
+	}
+	// Local provider stores under stt.localModelPath.
+	if _, err := SetSTTModel(path, STTProviderLocal, "/models/moonshine"); err != nil {
+		t.Fatalf("SetSTTModel local: %v", err)
+	}
+	cfg, _ = ValidateFile(path)
+	if cfg.STT.LocalModelPath != "/models/moonshine" {
+		t.Errorf("local model path = %q", cfg.STT.LocalModelPath)
+	}
+}

internal/config/types.go

@@ -97,6 +97,11 @@ type ToolsConfig struct {
 
 type PreferencesConfig struct {
 	FavoriteModels []string `json:"favoriteModels,omitempty"`
+	// RecentModels is the short automatic history of provider+model pairs the
+	// user has switched to via /model, newest first. Unlike FavoriteModels
+	// (manual pins), this list is maintained automatically on every switch and
+	// capped to MaxRecentModels entries. See RecentModelEntry.
+	RecentModels []RecentModelEntry `json:"recentModels,omitempty"`
 	// Theme is the persisted TUI palette preference — "auto" or a registered theme
 	// name (e.g. "dracula"). Applied at startup below the --theme flag and
 	// ZERO_THEME, so a /theme choice survives restart. Empty = unset (defaults auto).
@@ -107,6 +112,18 @@ type PreferencesConfig struct {
 	Recaps *bool `json:"recaps,omitempty"`
 }
 
+// RecentModelEntry is one provider-qualified model selection recorded in
+// Preferences.RecentModels. Provider is the saved provider profile's Name (not
+// a display label), so a recent entry can be resolved back to a concrete
+// profile the same way the /model picker's cross-provider rows are.
+type RecentModelEntry struct {
+	Provider string `json:"provider"`
+	Model    string `json:"model"`
+}
+
+// MaxRecentModels caps the persisted/displayed recent-selection history.
+const MaxRecentModels = 5
+
 // RecapsEnabled reports whether post-turn recaps are on. Unset defaults to ON.
 func (p PreferencesConfig) RecapsEnabled() bool {
 	return p.Recaps == nil || *p.Recaps
@@ -131,6 +148,115 @@ type KeyBindingsConfig struct {
 	ToggleSidebar KeyBindingDef `json:"toggleSidebar,omitempty"`
 }
 
+// STTProviderKind is the batch (or streaming) transcription backend selector.
+// Validated at config load time against the known set, so a typo fails loudly
+// with the valid options rather than silently falling back to a default.
+type STTProviderKind string
+
+const (
+	STTProviderLocal    STTProviderKind = "local"
+	STTProviderGroq     STTProviderKind = "groq"
+	STTProviderOpenAI   STTProviderKind = "openai"
+	STTProviderDeepgram STTProviderKind = "deepgram"
+)
+
+// STTConfig configures speech-to-text dictation. All fields are optional; empty
+// values take the documented defaults. Booleans that need a real tri-state
+// (distinguishing "unset" from "false") use *bool, matching PreferencesConfig.Recaps.
+type STTConfig struct {
+	// Provider is the batch transcription backend: "local" (sherpa-onnx-offline,
+	// the default), "groq", or "openai". Termux and the fallback everywhere use
+	// this path.
+	Provider STTProviderKind `json:"provider,omitempty"`
+	// StreamProvider is the streaming backend on desktop: "local" (sherpa-onnx
+	// websocket server, default), "deepgram", or "openai" (Realtime).
+	StreamProvider STTProviderKind `json:"streamProvider,omitempty"`
+	// Streaming enables the live-transcript pipeline on platforms that support
+	// it (desktop). Defaults to on; set false to always use the batch pipeline.
+	Streaming *bool `json:"streaming,omitempty"`
+	// Model overrides the cloud batch model (e.g. "whisper-large-v3-turbo" for
+	// Groq, "whisper-1" for OpenAI). Empty uses the provider default.
+	Model string `json:"model,omitempty"`
+	// StreamModel overrides the cloud streaming model (Deepgram/OpenAI Realtime).
+	StreamModel string `json:"streamModel,omitempty"`
+	// LocalModelPath is the sherpa-onnx model directory for local transcription
+	// (batch and streaming). Required to use a local provider.
+	LocalModelPath string `json:"localModelPath,omitempty"`
+	// LocalBinary overrides the offline binary name/path (default
+	// "sherpa-onnx-offline"); LocalServerBinary overrides the streaming server
+	// (default "sherpa-onnx-online-websocket-server"). Both looked up on PATH.
+	LocalBinary       string `json:"localBinary,omitempty"`
+	LocalServerBinary string `json:"localServerBinary,omitempty"`
+	// LocalServerPort is the localhost port for the sherpa-onnx websocket server
+	// (default 6006).
+	LocalServerPort int `json:"localServerPort,omitempty"`
+	// EngineVersion selects the sherpa-onnx release the auto-download fetches
+	// ("" → a pinned known-good default; "latest" or any release tag also works,
+	// so a newer engine needs no Zero update). Verified against the release's
+	// published SHA256 digest either way.
+	EngineVersion string `json:"engineVersion,omitempty"`
+	// NumThreads sets the local engine's thread count (0 = engine default).
+	NumThreads int `json:"numThreads,omitempty"`
+	// Language optionally constrains recognition (ISO-639-1, e.g. "en"). Empty =
+	// auto-detect.
+	Language string `json:"language,omitempty"`
+	// MaxDurationSeconds is the hard runaway-recording cap on every platform
+	// (0 = default 300s).
+	MaxDurationSeconds int `json:"maxDurationSeconds,omitempty"`
+	// SilenceAutoStop ends a recording ~2s after the signal goes quiet, as a
+	// backstop for a forgotten manual stop (not VAD-triggered start). Defaults on.
+	SilenceAutoStop *bool `json:"silenceAutoStop,omitempty"`
+	// AutoSubmit fires the transcript at the agent instead of inserting it for
+	// review. Defaults OFF — insert-for-review is the safety net for a misheard
+	// prompt (§3).
+	AutoSubmit *bool `json:"autoSubmit,omitempty"`
+	// WindowsAudioDevice names the dshow capture device (auto-detected when empty).
+	WindowsAudioDevice string `json:"windowsAudioDevice,omitempty"`
+}
+
+// STTProvider returns the configured batch provider, defaulting to local.
+func (c STTConfig) STTProvider() STTProviderKind {
+	if c.Provider == "" {
+		return STTProviderLocal
+	}
+	return c.Provider
+}
+
+// STTStreamProvider returns the configured streaming provider, defaulting to local.
+func (c STTConfig) STTStreamProvider() STTProviderKind {
+	if c.StreamProvider == "" {
+		return STTProviderLocal
+	}
+	return c.StreamProvider
+}
+
+// StreamingEnabled reports whether the live pipeline is on. Unset defaults ON.
+func (c STTConfig) StreamingEnabled() bool {
+	return c.Streaming == nil || *c.Streaming
+}
+
+// SilenceAutoStopEnabled reports whether trailing-silence auto-stop is on.
+// Unset defaults ON.
+func (c STTConfig) SilenceAutoStopEnabled() bool {
+	return c.SilenceAutoStop == nil || *c.SilenceAutoStop
+}
+
+// AutoSubmitEnabled reports whether transcripts are auto-fired. Unset defaults OFF.
+func (c STTConfig) AutoSubmitEnabled() bool {
+	return c.AutoSubmit != nil && *c.AutoSubmit
+}
+
+// Empty reports whether the STT config carries no user-set values (so it can be
+// omitted from a marshaled config).
+func (c STTConfig) Empty() bool {
+	return c.Provider == "" && c.StreamProvider == "" && c.Streaming == nil &&
+		c.Model == "" && c.StreamModel == "" && c.LocalModelPath == "" &&
+		c.LocalBinary == "" && c.LocalServerBinary == "" && c.LocalServerPort == 0 &&
+		c.EngineVersion == "" && c.NumThreads == 0 && c.Language == "" &&
+		c.MaxDurationSeconds == 0 && c.SilenceAutoStop == nil && c.AutoSubmit == nil &&
+		c.WindowsAudioDevice == ""
+}
+
 // LocalControlConfig controls local browser/desktop/terminal automation helpers.
 // Helpers are discovered lazily by the tool that needs them; no setup command or
 // background probe is required during startup.
@@ -227,6 +353,7 @@ type FileConfig struct {
 	Preferences    PreferencesConfig  `json:"preferences,omitempty"`
 	KeyBindings    KeyBindingsConfig  `json:"keybindings,omitempty"`
 	LocalControl   LocalControlConfig `json:"localControl,omitempty"`
+	STT            STTConfig          `json:"stt,omitempty"`
 }
 
 func (cfg FileConfig) MarshalJSON() ([]byte, error) {
@@ -242,6 +369,7 @@ func (cfg FileConfig) MarshalJSON() ([]byte, error) {
 		Preferences    PreferencesConfig   `json:"preferences,omitempty"`
 		KeyBindings    KeyBindingsConfig   `json:"keybindings,omitempty"`
 		LocalControl   *LocalControlConfig `json:"localControl,omitempty"`
+		STT            *STTConfig          `json:"stt,omitempty"`
 	}
 	raw := rawConfig{
 		ActiveProvider: cfg.ActiveProvider,
@@ -258,6 +386,9 @@ func (cfg FileConfig) MarshalJSON() ([]byte, error) {
 	if !cfg.LocalControl.Empty() {
 		raw.LocalControl = &cfg.LocalControl
 	}
+	if !cfg.STT.Empty() {
+		raw.STT = &cfg.STT
+	}
 	return json.Marshal(raw)
 }
 
@@ -280,6 +411,7 @@ type Overrides struct {
 	Tools          ToolsConfig
 	KeyBindings    KeyBindingsConfig
 	LocalControl   LocalControlConfig
+	STT            STTConfig
 }
 
 type ResolvedConfig struct {
@@ -295,6 +427,7 @@ type ResolvedConfig struct {
 	Preferences    PreferencesConfig
 	KeyBindings    KeyBindingsConfig
 	LocalControl   LocalControlConfig
+	STT            STTConfig
 }
 
 type MCPConfig struct {
@@ -312,6 +445,16 @@ type MCPServerConfig struct {
 	OAuth       *MCPOAuthConfig   `json:"oauth,omitempty"`
 	Disabled    bool              `json:"disabled,omitempty"`
 	disabledSet bool
+	// configured is true when the user's config JSON declared an object for
+	// this server at all (i.e. UnmarshalJSON ran for it), regardless of which
+	// fields it set or what values they hold. A built-in default seeded by
+	// DefaultMCPServers() is never unmarshaled from JSON, so it starts false;
+	// any explicit entry in the user/project file — even one that happens to
+	// repeat a default's exact field values (e.g. re-declaring firecrawl's
+	// default URL) — sets it true. IsUnconfiguredDefault checks this alongside
+	// a resolved-value comparison, so redeclaring default values verbatim still
+	// counts as user-configured.
+	configured bool
 }
 
 // MCPOAuthConfig describes how to authenticate to a remote MCP server using an
@@ -342,6 +485,7 @@ func (cfg *FileConfig) UnmarshalJSON(data []byte) error {
 		Preferences     PreferencesConfig          `json:"preferences"`
 		KeyBindings     KeyBindingsConfig          `json:"keybindings"`
 		LocalControl    LocalControlConfig         `json:"localControl"`
+		STT             STTConfig                  `json:"stt"`
 		MCPServers      map[string]MCPServerConfig `json:"mcpServers"`
 		MCPServersSnake map[string]MCPServerConfig `json:"mcp_servers"`
 	}
@@ -369,6 +513,7 @@ func (cfg *FileConfig) UnmarshalJSON(data []byte) error {
 	cfg.Preferences = raw.Preferences
 	cfg.KeyBindings = raw.KeyBindings
 	cfg.LocalControl = raw.LocalControl
+	cfg.STT = raw.STT
 	if cfg.MCP.Servers == nil && (len(raw.MCPServers) > 0 || len(raw.MCPServersSnake) > 0) {
 		cfg.MCP.Servers = map[string]MCPServerConfig{}
 	}
@@ -503,6 +648,10 @@ func (server *MCPServerConfig) UnmarshalJSON(data []byte) error {
 		server.Disabled = *raw.Disabled
 		server.disabledSet = true
 	}
+	// This method only runs when the user's JSON actually has an object for this
+	// server key (built-in defaults are seeded as Go struct literals, never
+	// unmarshaled), so reaching here at all means the user configured it.
+	server.configured = true
 	return nil
 }
 

internal/config/validate.go

@@ -54,5 +54,8 @@ func validateSemantics(cfg FileConfig) []Issue {
 		// normalizeProviders already redacts secrets via providerError.
 		return []Issue{{FieldPath: "providers", Message: err.Error()}}
 	}
+	if err := validateSTTConfig(cfg.STT); err != nil {
+		return []Issue{{FieldPath: "stt", Message: err.Error()}}
+	}
 	return nil
 }

internal/config/writer.go

@@ -7,6 +7,8 @@ import (
 	"path/filepath"
 	"sort"
 	"strings"
+
+	"github.com/Gitlawb/zero/internal/providercatalog"
 )
 
 func UpsertProvider(path string, profile ProviderProfile, setActive bool) (FileConfig, error) {
@@ -29,6 +31,20 @@ func UpsertProvider(path string, profile ProviderProfile, setActive bool) (FileC
 	}
 
 	mergeProvider(&cfg, profile)
+	// mergeProfile deliberately ignores APIKeyStored — during resolve-time
+	// layering a project config must not be able to claim the user's stored
+	// keys. This user-config WRITE path re-applies the marker: capturing a key
+	// via SecureProviderProfile onto a previously env/no-key profile must
+	// persist apiKeyStored, or the secret sits in the credential store while
+	// every ApplyStoredAPIKey gate skips it (PR #560 review).
+	if profile.APIKeyStored {
+		for index := range cfg.Providers {
+			if cfg.Providers[index].Name == profile.Name {
+				cfg.Providers[index].APIKeyStored = true
+				break
+			}
+		}
+	}
 	if setActive || strings.TrimSpace(cfg.ActiveProvider) == "" {
 		cfg.ActiveProvider = profile.Name
 	}
@@ -39,6 +55,62 @@ func UpsertProvider(path string, profile ProviderProfile, setActive bool) (FileC
 	return cfg, nil
 }
 
+// EnsuredProvider reports the outcome of EnsureCatalogProvider: the profile name
+// that serves the catalog entry, whether it was newly created, and which provider
+// is active after the call (unchanged unless it was blank).
+type EnsuredProvider struct {
+	Name    string
+	Created bool
+	Active  string
+}
+
+// EnsureCatalogProvider guarantees a provider profile exists in the config at
+// path for the given catalog entry. OAuth login flows call this right after
+// storing a token: a login is only reachable from the provider list and
+// `zero providers use` when a profile exists, but a login must never replace or
+// deactivate the user's current active provider — so an existing profile whose
+// Name or CatalogID already matches is left completely untouched (its name,
+// credentials, and model are the user's), and a created profile is NOT marked
+// active unless no provider was active at all.
+func EnsureCatalogProvider(path string, catalogID string) (EnsuredProvider, error) {
+	path = strings.TrimSpace(path)
+	if path == "" {
+		return EnsuredProvider{}, fmt.Errorf("config path is required")
+	}
+	descriptor, err := providercatalog.Require(catalogID)
+	if err != nil {
+		return EnsuredProvider{}, err
+	}
+
+	cfg := FileConfig{}
+	if data, err := os.ReadFile(path); err == nil {
+		if err := json.Unmarshal(data, &cfg); err != nil {
+			return EnsuredProvider{}, fmt.Errorf("invalid config JSON %s: %w", path, err)
+		}
+	} else if !os.IsNotExist(err) {
+		return EnsuredProvider{}, fmt.Errorf("read config %s: %w", path, err)
+	}
+	for _, provider := range cfg.Providers {
+		if strings.EqualFold(strings.TrimSpace(provider.CatalogID), descriptor.ID) ||
+			strings.EqualFold(strings.TrimSpace(provider.Name), descriptor.ID) {
+			return EnsuredProvider{Name: provider.Name, Active: cfg.ActiveProvider}, nil
+		}
+	}
+
+	profile := ProviderProfile{
+		Name:         descriptor.ID,
+		ProviderKind: providerKindForCatalogTransport(descriptor.Transport),
+		CatalogID:    descriptor.ID,
+		BaseURL:      descriptor.DefaultBaseURL,
+		Model:        descriptor.DefaultModel,
+	}
+	written, err := UpsertProvider(path, profile, false)
+	if err != nil {
+		return EnsuredProvider{}, err
+	}
+	return EnsuredProvider{Name: profile.Name, Created: true, Active: written.ActiveProvider}, nil
+}
+
 func SetActiveProvider(path string, name string) (FileConfig, error) {
 	path = strings.TrimSpace(path)
 	if path == "" {
@@ -72,6 +144,296 @@ func SetActiveProvider(path string, name string) (FileConfig, error) {
 	return FileConfig{}, fmt.Errorf("provider %q not found", name)
 }
 
+// RemoveProvider deletes the named provider profile from the config at path.
+// When the removed profile was active, activeProvider hands off to the first
+// remaining provider (or clears when none remain) so the config never points at
+// a profile that no longer exists. The caller owns cleaning up the credential
+// store entry — config stays pure of secret I/O on the read path, and remove
+// keeps that symmetry by only touching config.json.
+func RemoveProvider(path string, name string) (FileConfig, error) {
+	path = strings.TrimSpace(path)
+	if path == "" {
+		return FileConfig{}, fmt.Errorf("config path is required")
+	}
+	name = strings.TrimSpace(name)
+	if name == "" {
+		return FileConfig{}, fmt.Errorf("provider name is required")
+	}
+
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return FileConfig{}, fmt.Errorf("read config %s: %w", path, err)
+	}
+	cfg := FileConfig{}
+	if err := json.Unmarshal(data, &cfg); err != nil {
+		return FileConfig{}, fmt.Errorf("invalid config JSON %s: %w", path, err)
+	}
+
+	index := -1
+	for i, provider := range cfg.Providers {
+		if strings.EqualFold(strings.TrimSpace(provider.Name), name) {
+			index = i
+			break
+		}
+	}
+	if index < 0 {
+		return FileConfig{}, fmt.Errorf("provider %q not found", name)
+	}
+	removed := cfg.Providers[index]
+	cfg.Providers = append(cfg.Providers[:index], cfg.Providers[index+1:]...)
+	if strings.EqualFold(strings.TrimSpace(cfg.ActiveProvider), strings.TrimSpace(removed.Name)) {
+		cfg.ActiveProvider = ""
+		if len(cfg.Providers) > 0 {
+			cfg.ActiveProvider = cfg.Providers[0].Name
+		}
+	}
+	if err := writeConfigFile(path, cfg); err != nil {
+		return FileConfig{}, err
+	}
+	return cfg, nil
+}
+
+// RenameProvider renames a provider profile, keeping everything keyed by the
+// profile name consistent: the activeProvider pointer follows the rename, and a
+// key in the encrypted credential store (APIKeyStored) is migrated to the new
+// name BEFORE the config is rewritten — the store write must succeed first so a
+// failed migration never strands the config pointing at a key that no longer
+// resolves. OAuth tokens are deliberately not migrated: the runtime's login
+// candidates fall back to the profile's CatalogID, which every OAuth-capable
+// catalog profile carries, so a rename keeps the login reachable.
+func RenameProvider(path string, oldName string, newName string) (FileConfig, error) {
+	path = strings.TrimSpace(path)
+	if path == "" {
+		return FileConfig{}, fmt.Errorf("config path is required")
+	}
+	oldName = strings.TrimSpace(oldName)
+	newName = strings.TrimSpace(newName)
+	if oldName == "" || newName == "" {
+		return FileConfig{}, fmt.Errorf("provider names are required")
+	}
+
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return FileConfig{}, fmt.Errorf("read config %s: %w", path, err)
+	}
+	cfg := FileConfig{}
+	if err := json.Unmarshal(data, &cfg); err != nil {
+		return FileConfig{}, fmt.Errorf("invalid config JSON %s: %w", path, err)
+	}
+
+	index := -1
+	for i, provider := range cfg.Providers {
+		providerName := strings.TrimSpace(provider.Name)
+		if strings.EqualFold(providerName, oldName) {
+			index = i
+			continue
+		}
+		if strings.EqualFold(providerName, newName) {
+			return FileConfig{}, fmt.Errorf("provider %q already exists", newName)
+		}
+	}
+	if index < 0 {
+		return FileConfig{}, fmt.Errorf("provider %q not found", oldName)
+	}
+	if strings.EqualFold(oldName, newName) && cfg.Providers[index].Name == newName {
+		return cfg, nil
+	}
+
+	previousName := cfg.Providers[index].Name
+	keyMigrated := false
+	if cfg.Providers[index].APIKeyStored {
+		if err := migrateStoredProviderKey(path, previousName, newName); err != nil {
+			return FileConfig{}, fmt.Errorf("migrate stored key for %q: %w", oldName, err)
+		}
+		keyMigrated = true
+	}
+	if strings.EqualFold(strings.TrimSpace(cfg.ActiveProvider), strings.TrimSpace(previousName)) {
+		cfg.ActiveProvider = newName
+	}
+	cfg.Providers[index].Name = newName
+	if err := writeConfigFile(path, cfg); err != nil {
+		if keyMigrated {
+			// Compensate best-effort: config.json still names the OLD profile, so
+			// move the key back where that config can find it — otherwise a failed
+			// rewrite strands the key under a name no profile carries.
+			_ = migrateStoredProviderKey(path, newName, previousName)
+		}
+		return FileConfig{}, err
+	}
+	return cfg, nil
+}
+
+// ProviderEdit is a field-level edit of one saved provider, applied by
+// EditProvider in a single atomic write. Name is the CURRENT profile name
+// (matched case-insensitively); NewName renames (case-only renames included).
+// Empty BaseURL/Model/APIKey mean "leave unchanged"; Description is applied
+// VERBATIM (the editor always knows the full desired text, so clearing works).
+type ProviderEdit struct {
+	Name         string
+	NewName      string
+	BaseURL      string
+	Model        string
+	APIKey       string
+	APIKeyStored bool
+	Description  string
+}
+
+// EditProvider applies a provider edit in ONE read-modify-write: rename
+// (activeProvider follows; a stored key migrates, with a best-effort rollback
+// if the config write fails), field updates, the stored-key marker, and the
+// verbatim description. A single write keeps the operation atomic — the
+// previous rename+upsert+describe sequence could fail halfway and leave
+// config.json renamed while every in-memory consumer still held the old name —
+// and, unlike UpsertProvider's exact-name merge, the case-insensitive match
+// here makes a case-only rename (groq -> Groq) an in-place update instead of
+// an appended duplicate profile.
+func EditProvider(path string, edit ProviderEdit) (FileConfig, error) {
+	path = strings.TrimSpace(path)
+	if path == "" {
+		return FileConfig{}, fmt.Errorf("config path is required")
+	}
+	oldName := strings.TrimSpace(edit.Name)
+	if oldName == "" {
+		return FileConfig{}, fmt.Errorf("provider name is required")
+	}
+	newName := strings.TrimSpace(edit.NewName)
+	if newName == "" {
+		newName = oldName
+	}
+
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return FileConfig{}, fmt.Errorf("read config %s: %w", path, err)
+	}
+	cfg := FileConfig{}
+	if err := json.Unmarshal(data, &cfg); err != nil {
+		return FileConfig{}, fmt.Errorf("invalid config JSON %s: %w", path, err)
+	}
+
+	index := -1
+	for i, provider := range cfg.Providers {
+		providerName := strings.TrimSpace(provider.Name)
+		if strings.EqualFold(providerName, oldName) {
+			index = i
+			continue
+		}
+		if strings.EqualFold(providerName, newName) {
+			return FileConfig{}, fmt.Errorf("provider %q already exists", newName)
+		}
+	}
+	if index < 0 {
+		return FileConfig{}, fmt.Errorf("provider %q not found", oldName)
+	}
+
+	previousName := cfg.Providers[index].Name
+	renamed := previousName != newName
+	keyMigrated := false
+	// A rename moves the stored key along: either the profile's existing entry,
+	// or a replacement key the caller just captured — the contract is that a
+	// captured key is stored under the CURRENT name before EditProvider runs, so
+	// one migration covers both. migrateStoredProviderKey no-ops on case-only
+	// renames (the store normalizes names), so it cannot delete the key it just
+	// moved.
+	if renamed && (cfg.Providers[index].APIKeyStored || edit.APIKeyStored) {
+		if err := migrateStoredProviderKey(path, previousName, newName); err != nil {
+			return FileConfig{}, fmt.Errorf("migrate stored key for %q: %w", oldName, err)
+		}
+		keyMigrated = true
+	}
+	if renamed && strings.EqualFold(strings.TrimSpace(cfg.ActiveProvider), strings.TrimSpace(previousName)) {
+		cfg.ActiveProvider = newName
+	}
+
+	profile := &cfg.Providers[index]
+	profile.Name = newName
+	if baseURL := strings.TrimSpace(edit.BaseURL); baseURL != "" {
+		profile.BaseURL = baseURL
+	}
+	if model := strings.TrimSpace(edit.Model); model != "" {
+		profile.Model = model
+	}
+	if apiKey := strings.TrimSpace(edit.APIKey); apiKey != "" {
+		profile.APIKey = apiKey
+	}
+	if edit.APIKeyStored {
+		profile.APIKeyStored = true
+	}
+	profile.Description = strings.TrimSpace(edit.Description)
+
+	if err := writeConfigFile(path, cfg); err != nil {
+		if keyMigrated {
+			// Compensate best-effort: config.json still names the OLD profile, so
+			// move the key back where that config can find it.
+			_ = migrateStoredProviderKey(path, newName, previousName)
+		}
+		return FileConfig{}, err
+	}
+	return cfg, nil
+}
+
+// SetProviderDescription sets a provider's description VERBATIM — including to
+// empty. The generic UpsertProvider merge treats empty fields as "leave
+// unchanged", so clearing a description needs this dedicated setter.
+func SetProviderDescription(path string, name string, description string) (FileConfig, error) {
+	path = strings.TrimSpace(path)
+	if path == "" {
+		return FileConfig{}, fmt.Errorf("config path is required")
+	}
+	name = strings.TrimSpace(name)
+	if name == "" {
+		return FileConfig{}, fmt.Errorf("provider name is required")
+	}
+
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return FileConfig{}, fmt.Errorf("read config %s: %w", path, err)
+	}
+	cfg := FileConfig{}
+	if err := json.Unmarshal(data, &cfg); err != nil {
+		return FileConfig{}, fmt.Errorf("invalid config JSON %s: %w", path, err)
+	}
+	for index := range cfg.Providers {
+		if strings.EqualFold(strings.TrimSpace(cfg.Providers[index].Name), name) {
+			cfg.Providers[index].Description = strings.TrimSpace(description)
+			if err := writeConfigFile(path, cfg); err != nil {
+				return FileConfig{}, err
+			}
+			return cfg, nil
+		}
+	}
+	return FileConfig{}, fmt.Errorf("provider %q not found", name)
+}
+
+// migrateStoredProviderKey moves a credential-store entry to a new provider
+// name: write-new-then-delete-old, so an interruption can leave a duplicate but
+// never a missing key. A missing source entry is a no-op (the marker may be
+// stale); only a failed WRITE aborts the rename.
+func migrateStoredProviderKey(configPath string, oldName string, newName string) error {
+	// The store normalizes names case-insensitively, so a case-only rename
+	// (groq -> Groq) targets ONE entry: Set(new) rewrites it in place and
+	// Delete(old) would then remove the key that was just "moved". Nothing to
+	// migrate — the existing entry already serves the new name.
+	if strings.EqualFold(strings.TrimSpace(oldName), strings.TrimSpace(newName)) {
+		return nil
+	}
+	store, err := ProviderKeyStoreAt(filepath.Dir(configPath))
+	if err != nil {
+		return err
+	}
+	key, ok, err := store.Get(oldName)
+	if err != nil {
+		return err
+	}
+	if !ok || strings.TrimSpace(key) == "" {
+		return nil
+	}
+	if err := store.Set(newName, key); err != nil {
+		return err
+	}
+	_, _ = store.Delete(oldName)
+	return nil
+}
+
 func SetProviderModel(path string, name string, model string) (FileConfig, error) {
 	path = strings.TrimSpace(path)
 	if path == "" {
@@ -131,6 +493,32 @@ func SetFavoriteModels(path string, models []string) (FileConfig, error) {
 	return cfg, nil
 }
 
+// SetRecentModels persists the automatic recent-model-switch history,
+// mirroring SetFavoriteModels (read-modify-atomic-write). Unlike favorites,
+// order is preserved (newest first) rather than sorted, since it reflects
+// switch recency, not an alphabetical preference list.
+func SetRecentModels(path string, entries []RecentModelEntry) (FileConfig, error) {
+	path = strings.TrimSpace(path)
+	if path == "" {
+		return FileConfig{}, fmt.Errorf("config path is required")
+	}
+
+	cfg := FileConfig{}
+	if data, err := os.ReadFile(path); err == nil {
+		if err := json.Unmarshal(data, &cfg); err != nil {
+			return FileConfig{}, fmt.Errorf("invalid config JSON %s: %w", path, err)
+		}
+	} else if !os.IsNotExist(err) {
+		return FileConfig{}, fmt.Errorf("read config %s: %w", path, err)
+	}
+
+	cfg.Preferences.RecentModels = NormalizeRecentModels(entries)
+	if err := writeConfigFile(path, cfg); err != nil {
+		return FileConfig{}, err
+	}
+	return cfg, nil
+}
+
 // SetRecapsEnabled persists the post-turn recap preference, mirroring
 // SetFavoriteModels (read-modify-atomic-write).
 func SetRecapsEnabled(path string, enabled bool) (FileConfig, error) {
@@ -176,6 +564,106 @@ func SetTheme(path string, theme string) (FileConfig, error) {
 	return cfg, nil
 }
 
+// SetSTTModel persists the dictation model and its provider, mirroring
+// SetTheme (read-modify-atomic-write). provider must be one of the known STT
+// provider kinds; a local provider stores the model as stt.localModelPath,
+// otherwise as stt.model. A blank model clears the stored value for that slot.
+func SetSTTModel(path string, provider STTProviderKind, model string) (FileConfig, error) {
+	path = strings.TrimSpace(path)
+	if path == "" {
+		return FileConfig{}, fmt.Errorf("config path is required")
+	}
+	cfg := FileConfig{}
+	if data, err := os.ReadFile(path); err == nil {
+		if err := json.Unmarshal(data, &cfg); err != nil {
+			return FileConfig{}, fmt.Errorf("invalid config JSON %s: %w", path, err)
+		}
+	} else if !os.IsNotExist(err) {
+		return FileConfig{}, fmt.Errorf("read config %s: %w", path, err)
+	}
+	if provider != "" {
+		cfg.STT.Provider = provider
+	}
+	model = strings.TrimSpace(model)
+	if cfg.STT.STTProvider() == STTProviderLocal {
+		cfg.STT.LocalModelPath = model
+	} else {
+		cfg.STT.Model = model
+	}
+	if err := validateSTTConfig(cfg.STT); err != nil {
+		return FileConfig{}, err
+	}
+	if err := writeConfigFile(path, cfg); err != nil {
+		return FileConfig{}, err
+	}
+	return cfg, nil
+}
+
+// SetSTTLocalEngine persists the paths of an auto-downloaded local engine +
+// model and switches dictation to the local provider, mirroring SetTheme
+// (read-modify-atomic-write). streaming selects the pipeline matching the
+// downloaded model (a streaming transducer vs a batch model). Called after a
+// download completes.
+func SetSTTLocalEngine(path, binary, serverBinary, modelPath string, streaming bool) (FileConfig, error) {
+	path = strings.TrimSpace(path)
+	if path == "" {
+		return FileConfig{}, fmt.Errorf("config path is required")
+	}
+	cfg := FileConfig{}
+	if data, err := os.ReadFile(path); err == nil {
+		if err := json.Unmarshal(data, &cfg); err != nil {
+			return FileConfig{}, fmt.Errorf("invalid config JSON %s: %w", path, err)
+		}
+	} else if !os.IsNotExist(err) {
+		return FileConfig{}, fmt.Errorf("read config %s: %w", path, err)
+	}
+	cfg.STT.Provider = STTProviderLocal
+	// Point BOTH pipelines at the local engine. Without resetting StreamProvider, a
+	// previously-chosen cloud value (deepgram/openai) would still win in
+	// buildStreamingTranscriber, so the live transcript would keep hitting the cloud
+	// after the user switched to a downloaded local model.
+	cfg.STT.StreamProvider = STTProviderLocal
+	cfg.STT.LocalBinary = strings.TrimSpace(binary)
+	cfg.STT.LocalServerBinary = strings.TrimSpace(serverBinary)
+	cfg.STT.LocalModelPath = strings.TrimSpace(modelPath)
+	// Match the pipeline to the downloaded model: a streaming transducer drives
+	// the websocket server for a live transcript; a batch model uses the offline
+	// binary.
+	s := streaming
+	cfg.STT.Streaming = &s
+	if err := validateSTTConfig(cfg.STT); err != nil {
+		return FileConfig{}, err
+	}
+	if err := writeConfigFile(path, cfg); err != nil {
+		return FileConfig{}, err
+	}
+	return cfg, nil
+}
+
+// SetSTTProvider persists just the dictation batch provider, mirroring SetTheme.
+func SetSTTProvider(path string, provider STTProviderKind) (FileConfig, error) {
+	path = strings.TrimSpace(path)
+	if path == "" {
+		return FileConfig{}, fmt.Errorf("config path is required")
+	}
+	cfg := FileConfig{}
+	if data, err := os.ReadFile(path); err == nil {
+		if err := json.Unmarshal(data, &cfg); err != nil {
+			return FileConfig{}, fmt.Errorf("invalid config JSON %s: %w", path, err)
+		}
+	} else if !os.IsNotExist(err) {
+		return FileConfig{}, fmt.Errorf("read config %s: %w", path, err)
+	}
+	cfg.STT.Provider = provider
+	if err := validateSTTConfig(cfg.STT); err != nil {
+		return FileConfig{}, err
+	}
+	if err := writeConfigFile(path, cfg); err != nil {
+		return FileConfig{}, err
+	}
+	return cfg, nil
+}
+
 func normalizeFavoriteModels(models []string) []string {
 	seen := map[string]bool{}
 	favorites := make([]string, 0, len(models))
@@ -191,6 +679,35 @@ func normalizeFavoriteModels(models []string) []string {
 	return favorites
 }
 
+// NormalizeRecentModels trims, drops entries with no model id, de-duplicates
+// by provider+model pair (keeping the first/newest occurrence), and caps the
+// result to MaxRecentModels. Order is preserved — the caller is responsible
+// for passing entries newest-first. Exported so callers outside this package
+// (e.g. the TUI, which keeps its own in-memory copy of recent history) apply
+// the exact same normalization rules as the persisted config, instead of
+// maintaining a second, independently-drifting copy of this logic.
+func NormalizeRecentModels(entries []RecentModelEntry) []RecentModelEntry {
+	seen := map[string]bool{}
+	recent := make([]RecentModelEntry, 0, len(entries))
+	for _, entry := range entries {
+		provider := strings.TrimSpace(entry.Provider)
+		model := strings.TrimSpace(entry.Model)
+		if model == "" {
+			continue
+		}
+		key := strings.ToLower(provider) + "\x00" + model
+		if seen[key] {
+			continue
+		}
+		seen[key] = true
+		recent = append(recent, RecentModelEntry{Provider: provider, Model: model})
+		if len(recent) >= MaxRecentModels {
+			break
+		}
+	}
+	return recent
+}
+
 func writeConfigFile(path string, cfg FileConfig) error {
 	dir := filepath.Dir(path)
 	if dir != "." && dir != "" {

internal/config/writer_test.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"io/fs"
 	"os"
+	"os/exec"
 	"path/filepath"
 	"reflect"
 	"runtime"
@@ -272,6 +273,69 @@ func TestSetFavoriteModelsPersistsUserPreferences(t *testing.T) {
 	}
 }
 
+func TestSetRecentModelsPersistsOrderDedupesAndCaps(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "zero.json")
+	writeConfigFixture(t, path, FileConfig{
+		ActiveProvider: "openai",
+		Providers: []ProviderProfile{
+			{Name: "openai", ProviderKind: ProviderKindOpenAI, Model: "gpt-4.1"},
+		},
+	}, 0o600)
+
+	cfg, err := SetRecentModels(path, []RecentModelEntry{
+		{Provider: " openrouter ", Model: " google/gemini-2.5-pro "},
+		{Provider: "openrouter", Model: "minimax/minimax-m2.1"},
+		{Provider: "openrouter", Model: "google/gemini-2.5-pro"}, // duplicate pair, older: dropped
+		{Provider: "", Model: ""},                                // blank model: dropped
+		{Provider: "openrouter", Model: "a"},
+		{Provider: "openrouter", Model: "b"},
+		{Provider: "openrouter", Model: "c"},
+		{Provider: "openrouter", Model: "d"}, // beyond MaxRecentModels (5): dropped
+	})
+	if err != nil {
+		t.Fatalf("SetRecentModels() error = %v", err)
+	}
+
+	want := []RecentModelEntry{
+		{Provider: "openrouter", Model: "google/gemini-2.5-pro"},
+		{Provider: "openrouter", Model: "minimax/minimax-m2.1"},
+		{Provider: "openrouter", Model: "a"},
+		{Provider: "openrouter", Model: "b"},
+		{Provider: "openrouter", Model: "c"},
+	}
+	if !reflect.DeepEqual(cfg.Preferences.RecentModels, want) {
+		t.Fatalf("RecentModels = %#v, want %#v", cfg.Preferences.RecentModels, want)
+	}
+	persisted := readConfigFixture(t, path)
+	if !reflect.DeepEqual(persisted.Preferences.RecentModels, want) {
+		t.Fatalf("persisted RecentModels = %#v, want %#v", persisted.Preferences.RecentModels, want)
+	}
+	if persisted.ActiveProvider != "openai" || len(persisted.Providers) != 1 {
+		t.Fatalf("provider config was not preserved: %#v", persisted)
+	}
+}
+
+// Two providers offering the same model id must both survive normalization —
+// recent history de-duplicates by provider+model pair, not model id alone.
+func TestSetRecentModelsDedupesByProviderAndModelPair(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "zero.json")
+
+	cfg, err := SetRecentModels(path, []RecentModelEntry{
+		{Provider: "provider-a", Model: "shared-model"},
+		{Provider: "provider-b", Model: "shared-model"},
+	})
+	if err != nil {
+		t.Fatalf("SetRecentModels() error = %v", err)
+	}
+	want := []RecentModelEntry{
+		{Provider: "provider-a", Model: "shared-model"},
+		{Provider: "provider-b", Model: "shared-model"},
+	}
+	if !reflect.DeepEqual(cfg.Preferences.RecentModels, want) {
+		t.Fatalf("RecentModels = %#v, want both providers preserved: %#v", cfg.Preferences.RecentModels, want)
+	}
+}
+
 func TestSetThemePersistsUserPreference(t *testing.T) {
 	path := filepath.Join(t.TempDir(), "zero.json")
 	writeConfigFixture(t, path, FileConfig{
@@ -385,3 +449,545 @@ func readConfigFixture(t *testing.T, path string) FileConfig {
 	}
 	return cfg
 }
+
+func TestEnsureCatalogProviderCreatesProfileWithoutStealingActive(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "zero.json")
+	writeConfigFixture(t, path, FileConfig{
+		ActiveProvider: "opengateway",
+		Providers: []ProviderProfile{
+			{
+				Name:         "opengateway",
+				ProviderKind: ProviderKindOpenAICompatible,
+				BaseURL:      "https://gateway.example.com/v1",
+				APIKeyStored: true,
+				Model:        "some-model",
+			},
+		},
+	}, 0o600)
+
+	ensured, err := EnsureCatalogProvider(path, "chatgpt")
+	if err != nil {
+		t.Fatalf("EnsureCatalogProvider: %v", err)
+	}
+	if !ensured.Created {
+		t.Fatalf("expected profile to be created")
+	}
+	if ensured.Name != "chatgpt" {
+		t.Fatalf("expected profile name chatgpt, got %q", ensured.Name)
+	}
+	if ensured.Active != "opengateway" {
+		t.Fatalf("active provider must stay opengateway, got %q", ensured.Active)
+	}
+
+	cfg := readConfigFixture(t, path)
+	if cfg.ActiveProvider != "opengateway" {
+		t.Fatalf("persisted active provider changed to %q", cfg.ActiveProvider)
+	}
+	if len(cfg.Providers) != 2 {
+		t.Fatalf("expected 2 providers, got %d", len(cfg.Providers))
+	}
+	chatgpt := cfg.Providers[1]
+	if chatgpt.Name != "chatgpt" || chatgpt.CatalogID != "chatgpt" {
+		t.Fatalf("unexpected created profile: %+v", chatgpt)
+	}
+	if chatgpt.Model == "" || chatgpt.BaseURL == "" {
+		t.Fatalf("created profile must carry catalog defaults, got %+v", chatgpt)
+	}
+	if chatgpt.APIKey != "" || chatgpt.APIKeyStored {
+		t.Fatalf("OAuth-created profile must stay keyless, got %+v", chatgpt)
+	}
+}
+
+func TestEnsureCatalogProviderLeavesExistingProfileUntouched(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "zero.json")
+	original := FileConfig{
+		ActiveProvider: "opengateway",
+		Providers: []ProviderProfile{
+			{Name: "opengateway", ProviderKind: ProviderKindOpenAICompatible, BaseURL: "https://gateway.example.com/v1", Model: "some-model"},
+			// Renamed profile that already serves the chatgpt catalog entry.
+			{Name: "codex", CatalogID: "chatgpt", Model: "gpt-5.5"},
+		},
+	}
+	data := writeConfigFixture(t, path, original, 0o600)
+
+	ensured, err := EnsureCatalogProvider(path, "chatgpt")
+	if err != nil {
+		t.Fatalf("EnsureCatalogProvider: %v", err)
+	}
+	if ensured.Created {
+		t.Fatalf("existing profile must not be recreated")
+	}
+	if ensured.Name != "codex" {
+		t.Fatalf("expected existing profile name codex, got %q", ensured.Name)
+	}
+	after, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("read config: %v", err)
+	}
+	if string(after) != string(data) {
+		t.Fatalf("config rewritten for a no-op ensure:\nbefore: %s\nafter: %s", data, after)
+	}
+}
+
+func TestEnsureCatalogProviderActivatesOnEmptyConfig(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "zero.json")
+
+	ensured, err := EnsureCatalogProvider(path, "chatgpt")
+	if err != nil {
+		t.Fatalf("EnsureCatalogProvider: %v", err)
+	}
+	if !ensured.Created {
+		t.Fatalf("expected profile to be created")
+	}
+	if ensured.Active != "chatgpt" {
+		t.Fatalf("blank active must adopt the new provider, got %q", ensured.Active)
+	}
+}
+
+func TestEnsureCatalogProviderRejectsUnknownCatalogID(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "zero.json")
+	if _, err := EnsureCatalogProvider(path, "no-such-provider"); err == nil {
+		t.Fatalf("expected unknown catalog id to error")
+	}
+	if _, err := os.Stat(path); !errors.Is(err, fs.ErrNotExist) {
+		t.Fatalf("config must not be written for an unknown catalog id")
+	}
+}
+
+func TestRemoveProviderDeletesAndHandsOffActive(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "zero.json")
+	writeConfigFixture(t, path, FileConfig{
+		ActiveProvider: "beta",
+		Providers: []ProviderProfile{
+			{Name: "alpha", ProviderKind: ProviderKindOpenAICompatible, BaseURL: "https://a.example.com/v1", Model: "m1"},
+			{Name: "beta", ProviderKind: ProviderKindOpenAICompatible, BaseURL: "https://b.example.com/v1", Model: "m2"},
+		},
+	}, 0o600)
+
+	cfg, err := RemoveProvider(path, " BETA ")
+	if err != nil {
+		t.Fatalf("RemoveProvider() error = %v", err)
+	}
+	if len(cfg.Providers) != 1 || cfg.Providers[0].Name != "alpha" {
+		t.Fatalf("expected only alpha to remain, got %+v", cfg.Providers)
+	}
+	if cfg.ActiveProvider != "alpha" {
+		t.Fatalf("active must hand off to the first remaining provider, got %q", cfg.ActiveProvider)
+	}
+
+	persisted := readConfigFixture(t, path)
+	if len(persisted.Providers) != 1 || persisted.ActiveProvider != "alpha" {
+		t.Fatalf("persisted config wrong: %+v", persisted)
+	}
+
+	// Removing the last provider clears the active pointer entirely.
+	cfg, err = RemoveProvider(path, "alpha")
+	if err != nil {
+		t.Fatalf("RemoveProvider(last) error = %v", err)
+	}
+	if len(cfg.Providers) != 0 || cfg.ActiveProvider != "" {
+		t.Fatalf("expected empty providers and no active, got %+v", cfg)
+	}
+}
+
+func TestRemoveProviderKeepsActiveWhenOtherRemoved(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "zero.json")
+	writeConfigFixture(t, path, FileConfig{
+		ActiveProvider: "alpha",
+		Providers: []ProviderProfile{
+			{Name: "alpha", ProviderKind: ProviderKindOpenAICompatible, BaseURL: "https://a.example.com/v1", Model: "m1"},
+			{Name: "beta", ProviderKind: ProviderKindOpenAICompatible, BaseURL: "https://b.example.com/v1", Model: "m2"},
+		},
+	}, 0o600)
+
+	cfg, err := RemoveProvider(path, "beta")
+	if err != nil {
+		t.Fatalf("RemoveProvider() error = %v", err)
+	}
+	if cfg.ActiveProvider != "alpha" {
+		t.Fatalf("active provider must be untouched, got %q", cfg.ActiveProvider)
+	}
+}
+
+func TestRemoveProviderRejectsUnknownWithoutRewriting(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "zero.json")
+	before := writeConfigFixture(t, path, FileConfig{
+		ActiveProvider: "alpha",
+		Providers:      []ProviderProfile{{Name: "alpha", ProviderKind: ProviderKindOpenAICompatible, BaseURL: "https://a.example.com/v1", Model: "m1"}},
+	}, 0o600)
+
+	if _, err := RemoveProvider(path, "ghost"); err == nil {
+		t.Fatal("RemoveProvider() error = nil, want not-found error")
+	}
+	after, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("read config: %v", err)
+	}
+	if string(after) != string(before) {
+		t.Fatalf("config was rewritten for unknown provider")
+	}
+}
+
+func TestRenameProviderFollowsActiveAndMigratesStoredKey(t *testing.T) {
+	dir := t.TempDir()
+	// Force the file credential backend so the test never touches the real OS
+	// keyring regardless of platform.
+	t.Setenv("ZERO_CRED_STORAGE", "encrypted-file")
+	path := filepath.Join(dir, "config.json")
+	writeConfigFixture(t, path, FileConfig{
+		ActiveProvider: "oldname",
+		Providers: []ProviderProfile{
+			{Name: "oldname", ProviderKind: ProviderKindOpenAICompatible, BaseURL: "https://a.example.com/v1", APIKeyStored: true, Model: "m1"},
+			{Name: "other", ProviderKind: ProviderKindOpenAICompatible, BaseURL: "https://b.example.com/v1", Model: "m2"},
+		},
+	}, 0o600)
+	store, err := ProviderKeyStoreAt(dir)
+	if err != nil {
+		t.Fatalf("open store: %v", err)
+	}
+	if err := store.Set("oldname", "sk-secret"); err != nil {
+		t.Fatalf("seed store: %v", err)
+	}
+
+	cfg, err := RenameProvider(path, "oldname", "newname")
+	if err != nil {
+		t.Fatalf("RenameProvider() error = %v", err)
+	}
+	if cfg.ActiveProvider != "newname" {
+		t.Fatalf("active must follow the rename, got %q", cfg.ActiveProvider)
+	}
+	if cfg.Providers[0].Name != "newname" || !cfg.Providers[0].APIKeyStored {
+		t.Fatalf("renamed profile wrong: %+v", cfg.Providers[0])
+	}
+	if cfg.Providers[1].Name != "other" {
+		t.Fatalf("unrelated profile changed: %+v", cfg.Providers[1])
+	}
+
+	key, ok, err := store.Get("newname")
+	if err != nil || !ok || key != "sk-secret" {
+		t.Fatalf("stored key must migrate to the new name, got key=%q ok=%v err=%v", key, ok, err)
+	}
+	if _, ok, _ := store.Get("oldname"); ok {
+		t.Fatalf("old credential entry must be deleted after migration")
+	}
+}
+
+func TestRenameProviderRejectsCollisionAndUnknown(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "zero.json")
+	before := writeConfigFixture(t, path, FileConfig{
+		ActiveProvider: "alpha",
+		Providers: []ProviderProfile{
+			{Name: "alpha", ProviderKind: ProviderKindOpenAICompatible, BaseURL: "https://a.example.com/v1", Model: "m1"},
+			{Name: "beta", ProviderKind: ProviderKindOpenAICompatible, BaseURL: "https://b.example.com/v1", Model: "m2"},
+		},
+	}, 0o600)
+
+	if _, err := RenameProvider(path, "alpha", "BETA"); err == nil {
+		t.Fatal("rename onto an existing name must fail")
+	}
+	if _, err := RenameProvider(path, "ghost", "gamma"); err == nil {
+		t.Fatal("renaming an unknown provider must fail")
+	}
+	after, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("read config: %v", err)
+	}
+	if string(after) != string(before) {
+		t.Fatalf("config was rewritten by a rejected rename")
+	}
+}
+
+func TestUpsertProviderPreservesStoredKeyMarkerOnExistingProfile(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "zero.json")
+	// An env-keyed profile with NO stored-key marker — the shape a provider has
+	// before its key is captured into the credential store.
+	writeConfigFixture(t, path, FileConfig{
+		ActiveProvider: "groq",
+		Providers: []ProviderProfile{
+			{Name: "groq", ProviderKind: ProviderKindOpenAICompatible, BaseURL: "https://api.groq.com/openai/v1", APIKeyEnv: "GROQ_API_KEY", Model: "m1"},
+		},
+	}, 0o600)
+
+	// The manager/setup edit paths persist a SecureProviderProfile-shaped
+	// profile: key already in the store, marker set, inline key cleared.
+	cfg, err := UpsertProvider(path, ProviderProfile{Name: "groq", APIKeyStored: true}, false)
+	if err != nil {
+		t.Fatalf("UpsertProvider() error = %v", err)
+	}
+	if !cfg.Providers[0].APIKeyStored {
+		t.Fatalf("APIKeyStored marker must survive the merge, got %+v", cfg.Providers[0])
+	}
+	if cfg.Providers[0].APIKeyEnv != "GROQ_API_KEY" || cfg.Providers[0].BaseURL == "" {
+		t.Fatalf("other fields must be preserved: %+v", cfg.Providers[0])
+	}
+	persisted := readConfigFixture(t, path)
+	if !persisted.Providers[0].APIKeyStored {
+		t.Fatalf("marker not persisted to disk: %+v", persisted.Providers[0])
+	}
+}
+
+func TestSetProviderDescriptionSetsAndClears(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "zero.json")
+	writeConfigFixture(t, path, FileConfig{
+		ActiveProvider: "alpha",
+		Providers: []ProviderProfile{
+			{Name: "alpha", ProviderKind: ProviderKindOpenAICompatible, BaseURL: "https://a.example.com/v1", Model: "m1", Description: "old text"},
+		},
+	}, 0o600)
+
+	cfg, err := SetProviderDescription(path, " ALPHA ", "new text")
+	if err != nil {
+		t.Fatalf("SetProviderDescription() error = %v", err)
+	}
+	if cfg.Providers[0].Description != "new text" {
+		t.Fatalf("description not set: %+v", cfg.Providers[0])
+	}
+
+	// Clearing must persist too — the reason this setter exists (UpsertProvider's
+	// merge treats an empty description as "leave unchanged").
+	cfg, err = SetProviderDescription(path, "alpha", "  ")
+	if err != nil {
+		t.Fatalf("SetProviderDescription(clear) error = %v", err)
+	}
+	if cfg.Providers[0].Description != "" {
+		t.Fatalf("description not cleared: %+v", cfg.Providers[0])
+	}
+	persisted := readConfigFixture(t, path)
+	if persisted.Providers[0].Description != "" {
+		t.Fatalf("cleared description not persisted: %+v", persisted.Providers[0])
+	}
+
+	if _, err := SetProviderDescription(path, "ghost", "x"); err == nil {
+		t.Fatal("unknown provider must error")
+	}
+}
+
+func TestRenameProviderRollsBackKeyMigrationWhenConfigWriteFails(t *testing.T) {
+	if runtime.GOOS != "darwin" {
+		t.Skip("uses chflags uchg to force the config write to fail; macOS only")
+	}
+	dir := t.TempDir()
+	t.Setenv("ZERO_CRED_STORAGE", "encrypted-file")
+	path := filepath.Join(dir, "config.json")
+	writeConfigFixture(t, path, FileConfig{
+		ActiveProvider: "oldname",
+		Providers: []ProviderProfile{
+			{Name: "oldname", ProviderKind: ProviderKindOpenAICompatible, BaseURL: "https://a.example.com/v1", APIKeyStored: true, Model: "m1"},
+		},
+	}, 0o600)
+	store, err := ProviderKeyStoreAt(dir)
+	if err != nil {
+		t.Fatalf("open store: %v", err)
+	}
+	if err := store.Set("oldname", "sk-secret"); err != nil {
+		t.Fatalf("seed store: %v", err)
+	}
+
+	// Immutable flag: temp-file creation and store writes in the directory keep
+	// working, but the final rename over config.json fails — the exact window
+	// where a migrated key would otherwise strand under the new name.
+	if out, err := exec.Command("chflags", "uchg", path).CombinedOutput(); err != nil {
+		t.Skipf("chflags uchg unavailable: %v (%s)", err, out)
+	}
+	t.Cleanup(func() { _ = exec.Command("chflags", "nouchg", path).Run() })
+
+	if _, err := RenameProvider(path, "oldname", "newname"); err == nil {
+		t.Fatal("expected the config write to fail under the immutable flag")
+	}
+
+	key, ok, err := store.Get("oldname")
+	if err != nil || !ok || key != "sk-secret" {
+		t.Fatalf("key must be rolled back to the old name, got key=%q ok=%v err=%v", key, ok, err)
+	}
+	if _, ok, _ := store.Get("newname"); ok {
+		t.Fatalf("rolled-back migration must not leave a key under the new name")
+	}
+}
+
+// TestRenameProviderCaseOnlyKeepsStoredKey: the credential store normalizes
+// names case-insensitively, so a case-only rename targets ONE store entry —
+// migrating would Set and then Delete the same key, losing it (PR #560 review).
+func TestRenameProviderCaseOnlyKeepsStoredKey(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("ZERO_CRED_STORAGE", "encrypted-file")
+	path := filepath.Join(dir, "config.json")
+	writeConfigFixture(t, path, FileConfig{
+		ActiveProvider: "groq",
+		Providers: []ProviderProfile{
+			{Name: "groq", ProviderKind: ProviderKindOpenAICompatible, BaseURL: "https://api.groq.com/openai/v1", APIKeyStored: true, Model: "m1"},
+		},
+	}, 0o600)
+	store, err := ProviderKeyStoreAt(dir)
+	if err != nil {
+		t.Fatalf("open store: %v", err)
+	}
+	if err := store.Set("groq", "sk-secret"); err != nil {
+		t.Fatalf("seed store: %v", err)
+	}
+
+	cfg, err := RenameProvider(path, "groq", "Groq")
+	if err != nil {
+		t.Fatalf("RenameProvider() error = %v", err)
+	}
+	if cfg.Providers[0].Name != "Groq" || cfg.ActiveProvider != "Groq" {
+		t.Fatalf("case-only rename must still apply to config: %+v", cfg)
+	}
+	// The store is case-insensitive: the key must remain retrievable under the
+	// new casing (same entry), not deleted by a same-entry "migration".
+	if key, ok, err := store.Get("Groq"); err != nil || !ok || key != "sk-secret" {
+		t.Fatalf("stored key lost on case-only rename: key=%q ok=%v err=%v", key, ok, err)
+	}
+}
+
+func TestEditProviderAppliesRenameFieldsAndDescriptionAtomically(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("ZERO_CRED_STORAGE", "encrypted-file")
+	path := filepath.Join(dir, "config.json")
+	writeConfigFixture(t, path, FileConfig{
+		ActiveProvider: "groq",
+		Providers: []ProviderProfile{
+			{Name: "groq", ProviderKind: ProviderKindOpenAICompatible, BaseURL: "https://api.groq.com/openai/v1", APIKeyStored: true, Model: "m1", Description: "old text"},
+			{Name: "other", ProviderKind: ProviderKindOpenAICompatible, BaseURL: "https://o.example.com/v1", Model: "m2"},
+		},
+	}, 0o600)
+	store, err := ProviderKeyStoreAt(dir)
+	if err != nil {
+		t.Fatalf("open store: %v", err)
+	}
+	if err := store.Set("groq", "sk-old"); err != nil {
+		t.Fatalf("seed store: %v", err)
+	}
+
+	cfg, err := EditProvider(path, ProviderEdit{
+		Name:        "groq",
+		NewName:     "grok-main",
+		Model:       "m1-pro",
+		Description: "", // cleared — must persist verbatim
+	})
+	if err != nil {
+		t.Fatalf("EditProvider() error = %v", err)
+	}
+	edited := cfg.Providers[0]
+	if edited.Name != "grok-main" || edited.Model != "m1-pro" || edited.Description != "" {
+		t.Fatalf("edit not applied: %+v", edited)
+	}
+	if edited.BaseURL != "https://api.groq.com/openai/v1" || !edited.APIKeyStored {
+		t.Fatalf("untouched fields must survive: %+v", edited)
+	}
+	if cfg.ActiveProvider != "grok-main" {
+		t.Fatalf("active must follow the rename, got %q", cfg.ActiveProvider)
+	}
+	if key, ok, _ := store.Get("grok-main"); !ok || key != "sk-old" {
+		t.Fatalf("stored key must migrate with the rename, got %q ok=%v", key, ok)
+	}
+	if len(cfg.Providers) != 2 || cfg.Providers[1].Name != "other" {
+		t.Fatalf("unrelated profile changed: %+v", cfg.Providers)
+	}
+}
+
+// TestEditProviderCaseOnlyRenameUpdatesInPlace: the manager previously skipped
+// RenameProvider on case-insensitively-equal names and fell into UpsertProvider,
+// whose case-SENSITIVE merge appended a duplicate profile. EditProvider matches
+// case-insensitively, so a case-only rename is an in-place update and the store
+// entry (case-normalized) survives.
+func TestEditProviderCaseOnlyRenameUpdatesInPlace(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("ZERO_CRED_STORAGE", "encrypted-file")
+	path := filepath.Join(dir, "config.json")
+	writeConfigFixture(t, path, FileConfig{
+		ActiveProvider: "groq",
+		Providers: []ProviderProfile{
+			{Name: "groq", ProviderKind: ProviderKindOpenAICompatible, BaseURL: "https://api.groq.com/openai/v1", APIKeyStored: true, Model: "m1"},
+		},
+	}, 0o600)
+	store, err := ProviderKeyStoreAt(dir)
+	if err != nil {
+		t.Fatalf("open store: %v", err)
+	}
+	if err := store.Set("groq", "sk-secret"); err != nil {
+		t.Fatalf("seed store: %v", err)
+	}
+
+	cfg, err := EditProvider(path, ProviderEdit{Name: "groq", NewName: "Groq"})
+	if err != nil {
+		t.Fatalf("EditProvider() error = %v", err)
+	}
+	if len(cfg.Providers) != 1 {
+		t.Fatalf("case-only rename must not duplicate the profile: %+v", cfg.Providers)
+	}
+	if cfg.Providers[0].Name != "Groq" || !cfg.Providers[0].APIKeyStored {
+		t.Fatalf("in-place update wrong: %+v", cfg.Providers[0])
+	}
+	if cfg.Providers[0].BaseURL != "https://api.groq.com/openai/v1" {
+		t.Fatalf("fields must survive a case-only rename: %+v", cfg.Providers[0])
+	}
+	if cfg.ActiveProvider != "Groq" {
+		t.Fatalf("active must follow, got %q", cfg.ActiveProvider)
+	}
+	if key, ok, _ := store.Get("Groq"); !ok || key != "sk-secret" {
+		t.Fatalf("stored key lost on case-only rename: %q ok=%v", key, ok)
+	}
+}
+
+// TestEditProviderRenameMigratesFreshlyCapturedKey: replacing the key AND
+// renaming in one edit — the caller captures under the CURRENT name and the
+// rename migration moves it, so the new key lands under the new name.
+func TestEditProviderRenameMigratesFreshlyCapturedKey(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("ZERO_CRED_STORAGE", "encrypted-file")
+	path := filepath.Join(dir, "config.json")
+	writeConfigFixture(t, path, FileConfig{
+		ActiveProvider: "gw",
+		Providers: []ProviderProfile{
+			{Name: "gw", ProviderKind: ProviderKindOpenAICompatible, BaseURL: "https://gw.example.com/v1", APIKeyEnv: "GW_KEY", Model: "m1"},
+		},
+	}, 0o600)
+	store, err := ProviderKeyStoreAt(dir)
+	if err != nil {
+		t.Fatalf("open store: %v", err)
+	}
+	// The caller's contract: a replacement key is stored under the CURRENT name
+	// before EditProvider runs (what SecureProviderProfile does).
+	if err := store.Set("gw", "sk-new"); err != nil {
+		t.Fatalf("seed store: %v", err)
+	}
+
+	cfg, err := EditProvider(path, ProviderEdit{Name: "gw", NewName: "gateway", APIKeyStored: true})
+	if err != nil {
+		t.Fatalf("EditProvider() error = %v", err)
+	}
+	if !cfg.Providers[0].APIKeyStored || cfg.Providers[0].Name != "gateway" {
+		t.Fatalf("marker/rename wrong: %+v", cfg.Providers[0])
+	}
+	if key, ok, _ := store.Get("gateway"); !ok || key != "sk-new" {
+		t.Fatalf("captured key must migrate to the new name, got %q ok=%v", key, ok)
+	}
+	if _, ok, _ := store.Get("gw"); ok {
+		t.Fatalf("old entry must be cleaned up after migration")
+	}
+}
+
+func TestEditProviderRejectsCollisionAndUnknown(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "config.json")
+	before := writeConfigFixture(t, path, FileConfig{
+		ActiveProvider: "alpha",
+		Providers: []ProviderProfile{
+			{Name: "alpha", ProviderKind: ProviderKindOpenAICompatible, BaseURL: "https://a.example.com/v1", Model: "m1"},
+			{Name: "beta", ProviderKind: ProviderKindOpenAICompatible, BaseURL: "https://b.example.com/v1", Model: "m2"},
+		},
+	}, 0o600)
+
+	if _, err := EditProvider(path, ProviderEdit{Name: "alpha", NewName: "BETA"}); err == nil {
+		t.Fatal("rename onto an existing name must fail")
+	}
+	if _, err := EditProvider(path, ProviderEdit{Name: "ghost", Model: "x"}); err == nil {
+		t.Fatal("editing an unknown provider must fail")
+	}
+	after, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("read config: %v", err)
+	}
+	if string(after) != string(before) {
+		t.Fatalf("config was rewritten by a rejected edit")
+	}
+}

internal/dictation/dictation.go

@@ -0,0 +1,104 @@
+// Package dictation implements speech-to-text capture and transcription for
+// the composer: press a key, talk, and the transcript lands in the input for
+// review — never auto-fired at the agent.
+//
+// Two pipelines share a keybinding and a composer-insertion target:
+//
+//   - Batch: record to a temp WAV file (Recorder.Start/Stop), then transcribe
+//     in one shot (Transcriber.Transcribe) — a local sherpa-onnx-offline exec
+//     or a single HTTPS POST to Groq/OpenAI. The only pipeline on Termux.
+//   - Streaming: capture raw PCM from the mic tool's stdout
+//     (Recorder.StartStreaming), feed 50ms chunks to a websocket
+//     (Transcriber.StreamTranscribe), and render partial transcripts live.
+//
+// Every OS integration shells out via exec.Command with discrete argv — never
+// a shell string, never CGO — matching internal/imageinput/clipboard.go. The
+// external binaries (arecord/sox/ffmpeg/termux-microphone-record, sherpa-onnx)
+// are looked up on PATH and degrade to a clear setup message when missing,
+// matching internal/lsp's philosophy for language servers.
+package dictation
+
+import (
+	"bytes"
+	"fmt"
+)
+
+// Batch transcription providers (config value stt.provider).
+const (
+	ProviderLocal  = "local"
+	ProviderGroq   = "groq"
+	ProviderOpenAI = "openai"
+)
+
+// Streaming transcription providers (config value stt.streamProvider).
+const (
+	StreamProviderLocal    = "local"
+	StreamProviderDeepgram = "deepgram"
+	StreamProviderOpenAI   = "openai"
+)
+
+// BatchProviders lists valid stt.provider values, for config validation.
+func BatchProviders() []string {
+	return []string{ProviderLocal, ProviderGroq, ProviderOpenAI}
+}
+
+// StreamProviders lists valid stt.streamProvider values, for config validation.
+func StreamProviders() []string {
+	return []string{StreamProviderLocal, StreamProviderDeepgram, StreamProviderOpenAI}
+}
+
+// AudioFormat identifies a recorded container format, sniffed from the bytes —
+// desktop recorders produce WAV, Termux's recorder produces M4A/AAC.
+type AudioFormat string
+
+const (
+	FormatWAV     AudioFormat = "wav"
+	FormatM4A     AudioFormat = "m4a"
+	FormatUnknown AudioFormat = ""
+)
+
+// SniffFormat detects the audio container from magic bytes. WAV is
+// "RIFF....WAVE"; MP4-family (Termux's .m4a) has "ftyp" at offset 4.
+func SniffFormat(data []byte) AudioFormat {
+	if len(data) >= 12 && bytes.Equal(data[:4], []byte("RIFF")) && bytes.Equal(data[8:12], []byte("WAVE")) {
+		return FormatWAV
+	}
+	if len(data) >= 8 && bytes.Equal(data[4:8], []byte("ftyp")) {
+		return FormatM4A
+	}
+	return FormatUnknown
+}
+
+// FileName returns a transcription-upload filename for the format.
+func (f AudioFormat) FileName() string {
+	switch f {
+	case FormatM4A:
+		return "audio.m4a"
+	default:
+		return "audio.wav"
+	}
+}
+
+// SetupError reports a missing external tool with install guidance. Missing
+// binaries are an expected condition (the user hasn't set dictation up yet),
+// not a bug — callers show the hint instead of a raw exec error.
+type SetupError struct {
+	Tool string
+	Hint string
+}
+
+func (e *SetupError) Error() string {
+	return fmt.Sprintf("%s not found — %s", e.Tool, e.Hint)
+}
+
+// AuthError reports that a cloud provider rejected a transcription request for
+// authentication reasons (HTTP 401/403) — a missing or invalid API key. It is a
+// fixable credential problem, so callers (the TUI) can offer an inline key
+// prompt for Provider instead of a dead-end error. Message is the already-
+// classified, secret-redacted user-facing text.
+type AuthError struct {
+	Provider string
+	Message  string
+}
+
+func (e *AuthError) Error() string { return e.Message }

internal/dictation/download.go

@@ -0,0 +1,893 @@
+package dictation
+
+import (
+	"archive/tar"
+	"compress/bzip2"
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+)
+
+// Auto-download of the local engine + a default model (opt-in, behind a confirm
+// in the F9 flow). Assets come from the official k2-fsa/sherpa-onnx GitHub
+// releases and are verified against a SHA256 digest before use — the same trust
+// boundary as installing them yourself, automated. Auto-downloading a native
+// executable is a real trust decision, which is why it is opt-in and verified.
+//
+// Rather than freeze a single hardcoded version, the downloader resolves the
+// release ASSETS via the GitHub API at download time and verifies each download
+// against the API's per-asset digest — so a newer sherpa-onnx release (or
+// "latest") works with no code change. A known-good version is still the DEFAULT
+// (reproducible, smoke-tested), and for that default the resolved digest is
+// cross-checked against a pinned value so a silently-changed release is caught.
+
+// DefaultSherpaVersion is the pinned, smoke-tested release used unless
+// stt.engineVersion overrides it. "latest" or any tag also works.
+const DefaultSherpaVersion = "v1.13.3"
+
+const (
+	sherpaRepo      = "k2-fsa/sherpa-onnx"
+	modelReleaseTag = "asr-models" // rolling release the ASR models live in
+	modelAssetName  = "sherpa-onnx-moonshine-tiny-en-int8.tar.bz2"
+	defaultAPIBase  = "https://api.github.com"
+)
+
+// engineAssetSuffix maps GOOS-GOARCH to the version-independent suffix of the
+// sherpa-onnx executable bundle for that platform. Matching by suffix (not a
+// full version-embedded name) is what lets any release resolve. The bundles are
+// self-contained (RPATH $ORIGIN/../lib), so the extracted bin/ executables run
+// with no library-path setup.
+var engineAssetSuffix = map[string]string{
+	"linux-amd64":   "linux-x64-shared-no-tts.tar.bz2",
+	"darwin-arm64":  "osx-arm64-shared-no-tts.tar.bz2",
+	"darwin-amd64":  "osx-x64-shared-no-tts.tar.bz2",
+	"windows-amd64": "win-x64-shared-MT-Release-no-tts.tar.bz2",
+}
+
+// pinnedEngineDigest cross-checks the DefaultSherpaVersion engine assets (a
+// silently-changed pinned release is refused). Empty for non-default versions,
+// which are verified against the API digest only.
+var pinnedEngineDigest = map[string]string{
+	"linux-amd64":   "e5cbfd96f3666c25d2272d468e337764fce6a4d50ed074e4b8e5021bfd7fefc1",
+	"darwin-arm64":  "ea73233bc250019ccf1f8a16feb29460efcd3425b50cac16980bcb76281d60bf",
+	"darwin-amd64":  "563423887d63d8a831c473e0ab6815139fe2e7a3482936716c2a128071dd217f",
+	"windows-amd64": "343c6c39cb4fe1880a9fb1abc8401d5174629ccbb147fca1fd53c440b2664570",
+}
+
+// pinnedModelDigest cross-checks the default Moonshine-tiny int8 model.
+const pinnedModelDigest = "d5fe6ec4334fef36255b2a4010412cad4c007e33103fec62fb5d17cad88086f2"
+
+// ModelVariant is a downloadable model the /stt-model picker offers, with a
+// pinned SHA256 (the model release predates GitHub's per-asset digests, so these
+// must be pinned). Batch variants use the offline binary; the streaming variant
+// (a transducer) drives the websocket server for a live transcript.
+type ModelVariant struct {
+	ID          string
+	Label       string
+	Description string
+	Bytes       int64
+	AssetName   string
+	Digest      string
+	DirName     string
+	Streaming   bool
+	// Recommended marks a curated, checksum-pinned, validated model (shown first).
+	Recommended bool
+}
+
+// ModelVariants returns the curated English models the download picker offers.
+// This is a hand-picked shortlist (each pinned by SHA256 since the model release
+// predates GitHub's per-asset digests), NOT the whole sherpa-onnx model zoo —
+// many more models (other languages, sizes, and streaming/batch families) work
+// via a manual stt.localModelPath. Streaming (live) options come first.
+func ModelVariants() []ModelVariant {
+	return []ModelVariant{
+		// Live / streaming — transcript builds up as you speak.
+		// DirName MUST match what ListModels derives from the asset ("model-"+id, id =
+		// asset minus "sherpa-onnx-" prefix and ".tar.bz2" suffix, dates included) so a
+		// model extracts to the same directory whether picked from the curated shortlist
+		// or the full browse list — otherwise installed-detection disagrees between the
+		// two views and the same model can be downloaded twice. Recommended matches the
+		// full list too (recommendedModelIDs marks every curated variant), so the ★ and
+		// ordering don't change when the background fetch swaps the curated list out.
+		{
+			ID: "streaming-zipformer-en-kroko", Label: "Kroko (newest, fastest)",
+			Description: "smallest live model", Bytes: 54 << 20,
+			AssetName:   "sherpa-onnx-streaming-zipformer-en-kroko-2025-08-06.tar.bz2",
+			Digest:      "c8676e5ff9ac2a85296e53ee0fd4d5fb1db6770e7a7647166eeafe349ade6834",
+			DirName:     "model-streaming-zipformer-en-kroko-2025-08-06",
+			Streaming:   true,
+			Recommended: true,
+		},
+		{
+			ID: "streaming-zipformer-20m", Label: "Zipformer 20M",
+			Description: "small, well-tested", Bytes: 121 << 20,
+			AssetName: "sherpa-onnx-streaming-zipformer-en-20M-2023-02-17.tar.bz2",
+			Digest:    "9c559283e8498d3fe95913c79ca1cb454bb26281ac2b102b41306c7d752765d9",
+			DirName:   "model-streaming-zipformer-en-20M-2023-02-17",
+			Streaming: true,
+		},
+		{
+			ID: "streaming-zipformer", Label: "Zipformer",
+			Description: "larger, more accurate", Bytes: 297 << 20,
+			AssetName: "sherpa-onnx-streaming-zipformer-en-2023-06-26.tar.bz2",
+			Digest:    "639e25b578e9e997131402199419c13a941f8e4e198e2da1ce57dbf5cf401282",
+			DirName:   "model-streaming-zipformer-en-2023-06-26",
+			Streaming: true,
+		},
+		{
+			ID: "nemo-streaming-fast-conformer-transducer-en-80ms-int8", Label: "NeMo streaming (fast)",
+			Description: "low-latency English", Bytes: 98 << 20,
+			AssetName:   "sherpa-onnx-nemo-streaming-fast-conformer-transducer-en-80ms-int8.tar.bz2",
+			Digest:      "7bd33a914e93370a1ba9c2066d9e841bdcad8613fa2a00537c1ae15d851a14d8",
+			DirName:     "model-nemo-streaming-fast-conformer-transducer-en-80ms-int8",
+			Streaming:   true,
+			Recommended: true,
+		},
+		// Batch — transcribes once when you stop.
+		{
+			ID: "moonshine-tiny", Label: "Moonshine tiny",
+			Description: "fast, smallest", Bytes: 103 << 20,
+			AssetName: "sherpa-onnx-moonshine-tiny-en-int8.tar.bz2",
+			Digest:    pinnedModelDigest,
+			DirName:   "model-moonshine-tiny-en-int8",
+		},
+		{
+			ID: "moonshine-base", Label: "Moonshine base",
+			Description: "more accurate, larger", Bytes: 239 << 20,
+			AssetName:   "sherpa-onnx-moonshine-base-en-int8.tar.bz2",
+			Digest:      "21870cecaa2e44e4e2bf63e02d1072bed183ccd10284871353bd9d24dad14e5e",
+			DirName:     "model-moonshine-base-en-int8",
+			Recommended: true,
+		},
+		{
+			ID: "sense-voice-zh-en-ja-ko-yue-int8-2025-09-09", Label: "SenseVoice",
+			Description: "multilingual, accurate", Bytes: 158 << 20,
+			AssetName:   "sherpa-onnx-sense-voice-zh-en-ja-ko-yue-int8-2025-09-09.tar.bz2",
+			Digest:      "7305f7905bfcf77fa0b39388a313f3da35c68d971661a65475b56fb2162c8e63",
+			DirName:     "model-sense-voice-zh-en-ja-ko-yue-int8-2025-09-09",
+			Recommended: true,
+		},
+		{
+			// Heavy (~1 GB) but the best transcription quality — recommended when
+			// accuracy matters more than speed/size. The asr-models release publishes
+			// no digest for it, so (like every browse-listed model) it downloads with
+			// TLS-only verification.
+			ID: "whisper-large-v3", Label: "Whisper large v3",
+			Description: "best accuracy, heavy", Bytes: 1019 << 20,
+			AssetName:   "sherpa-onnx-whisper-large-v3.tar.bz2",
+			DirName:     "model-whisper-large-v3",
+			Recommended: true,
+		},
+	}
+}
+
+// recommendedModelIDs marks the curated variants flagged Recommended so the full
+// browse list stars (and surfaces) exactly the ones the curated shortlist does —
+// keyed off the same Recommended flag so the two views never disagree.
+var recommendedModelIDs = func() map[string]bool {
+	m := map[string]bool{}
+	for _, v := range ModelVariants() {
+		if v.Recommended {
+			m[v.AssetName] = true
+		}
+	}
+	return m
+}()
+
+// pinnedModelDigests maps a model asset name to its pinned SHA256 (the curated
+// variants), so browse-listed models we happen to know get verified too.
+var pinnedModelDigests = func() map[string]string {
+	m := map[string]string{}
+	for _, v := range ModelVariants() {
+		m[v.AssetName] = v.Digest
+	}
+	return m
+}()
+
+// curatedLabels maps a curated model's asset name to its friendly label, so the
+// recommended rows read nicely in the full browse list too.
+var curatedLabels = func() map[string]string {
+	m := map[string]string{}
+	for _, v := range ModelVariants() {
+		m[v.AssetName] = v.Label
+	}
+	return m
+}()
+
+// browseLabel turns a raw asset id into a shorter display label: it drops the
+// redundant "-int8"/quantization noise and the "streaming-" prefix (the group
+// header already says live vs batch).
+func browseLabel(id string) string {
+	label := strings.TrimPrefix(id, "streaming-")
+	for _, drop := range []string{"-int8", ".int8", "-quantized", "-fp16"} {
+		label = strings.ReplaceAll(label, drop, "")
+	}
+	return label
+}
+
+// ListModels fetches every transcription model in the sherpa-onnx asr-models
+// release and returns them as variants (the curated ones flagged Recommended and
+// carrying a pinned digest; the rest with an empty digest, downloaded with
+// TLS-only verification since that release predates GitHub's per-asset digests).
+// Non-ASR assets (VAD, TTS, punctuation, speaker/keyword/…): filtered out.
+func ListModels(ctx context.Context, client *http.Client, apiBase string) ([]ModelVariant, error) {
+	if client == nil {
+		client = http.DefaultClient
+	}
+	if apiBase == "" {
+		apiBase = defaultAPIBase
+	}
+	// Resolve the release id, then page its assets (a release can have hundreds).
+	relURL := fmt.Sprintf("%s/repos/%s/releases/tags/%s", strings.TrimRight(apiBase, "/"), sherpaRepo, modelReleaseTag)
+	var rel struct {
+		ID     int64 `json:"id"`
+		Assets []githubAsset
+	}
+	if err := getJSON(ctx, client, relURL, &rel); err != nil {
+		return nil, fmt.Errorf("listing dictation models: %w", err)
+	}
+	assets := rel.Assets
+	// If the inline assets look capped, page the assets endpoint for the rest.
+	for page := 1; len(assets)%100 == 0 && len(assets) > 0; page++ {
+		var more []githubAsset
+		u := fmt.Sprintf("%s/repos/%s/releases/%d/assets?per_page=100&page=%d", strings.TrimRight(apiBase, "/"), sherpaRepo, rel.ID, page+1)
+		if err := getJSON(ctx, client, u, &more); err != nil || len(more) == 0 {
+			break
+		}
+		assets = append(assets, more...)
+		if len(more) < 100 {
+			break
+		}
+	}
+
+	seen := map[string]bool{}
+	var out []ModelVariant
+	for _, a := range assets {
+		if seen[a.Name] || !isTranscriptionModelAsset(a.Name) {
+			continue
+		}
+		seen[a.Name] = true
+		id := strings.TrimSuffix(strings.TrimPrefix(a.Name, "sherpa-onnx-"), ".tar.bz2")
+		digest := strings.TrimPrefix(a.Digest, "sha256:")
+		if digest == "" {
+			digest = pinnedModelDigests[a.Name] // may still be empty (browse/unverified)
+		}
+		label := browseLabel(id)
+		desc := modelFamily(a.Name) // readable language, e.g. "French"
+		if nice, ok := curatedLabels[a.Name]; ok {
+			label = nice
+			desc = curatedDescriptions[a.Name] // curated blurb ("fast, smallest")
+		}
+		out = append(out, ModelVariant{
+			ID:          id,
+			Label:       label,
+			Description: desc,
+			Bytes:       a.Size,
+			AssetName:   a.Name,
+			Digest:      digest,
+			DirName:     "model-" + id,
+			Streaming:   strings.Contains(strings.ToLower(a.Name), "streaming-"),
+			Recommended: recommendedModelIDs[a.Name],
+		})
+	}
+	return out, nil
+}
+
+type githubAsset struct {
+	Name   string `json:"name"`
+	Digest string `json:"digest"`
+	Size   int64  `json:"size"`
+}
+
+func getJSON(ctx context.Context, client *http.Client, url string, v any) error {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return err
+	}
+	req.Header.Set("Accept", "application/vnd.github+json")
+	resp, err := client.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("GitHub API HTTP %d", resp.StatusCode)
+	}
+	return json.NewDecoder(resp.Body).Decode(v)
+}
+
+// isTranscriptionModelAsset reports whether an asset is a speech-to-text model
+// (as opposed to a VAD/TTS/punctuation/speaker/keyword/enhancement tool).
+func isTranscriptionModelAsset(name string) bool {
+	n := strings.ToLower(name)
+	if !strings.HasPrefix(n, "sherpa-onnx-") || !strings.HasSuffix(n, ".tar.bz2") {
+		return false
+	}
+	for _, bad := range []string{
+		"-vad", "vad-", "tts", "punct", "speaker", "diariz", "kws", "keyword",
+		"audio-tagging", "denois", "source-separation", "speech-enhancement",
+		"spoken-language", "language-identification", "-lid", "melo", "kokoro",
+		"vits", "matcha", "piper", "wespeaker",
+		// Rockchip NPU (RKNN) builds for specific ARM boards — not CPU/ONNX, so
+		// the standard sherpa-onnx binary can't run them.
+		"rknn", "rk3566", "rk3568", "rk3562", "rk3588", "rk3576", "rk3528", "rk3399",
+	} {
+		if strings.Contains(n, bad) {
+			return false
+		}
+	}
+	for _, fam := range []string{
+		"zipformer", "moonshine", "whisper", "paraformer", "sense-voice",
+		"sensevoice", "conformer", "nemo", "canary", "parakeet", "fire-red",
+		"fireredasr", "dolphin", "telespeech", "wenet", "omnilingual", "funasr",
+		"medasr", "cohere", "qwen", "citrinet", "transducer", "-ctc-", "zipvoice",
+	} {
+		if strings.Contains(n, fam) {
+			return true
+		}
+	}
+	return false
+}
+
+// langNames maps ISO-ish language tokens in a model name to readable names.
+var langNames = map[string]string{
+	"en": "English", "zh": "Chinese", "yue": "Cantonese", "fr": "French",
+	"de": "German", "es": "Spanish", "ru": "Russian", "ja": "Japanese",
+	"ko": "Korean", "bn": "Bengali", "ar": "Arabic", "hi": "Hindi",
+	"pt": "Portuguese", "nl": "Dutch", "vi": "Vietnamese", "th": "Thai",
+	"uk": "Ukrainian", "fa": "Persian", "pl": "Polish", "tr": "Turkish",
+	"cs": "Czech", "sv": "Swedish", "fil": "Filipino", "tl": "Tagalog",
+	"fi": "Finnish", "el": "Greek", "he": "Hebrew", "ro": "Romanian",
+}
+
+// modelFamily is a short readable descriptor for a model, favoring the language
+// (the most useful thing not already obvious from the group header) and falling
+// back to the family. E.g. "French", "Chinese", "Multilingual".
+func modelFamily(name string) string {
+	n := strings.ToLower(name)
+	if strings.Contains(n, "multi") || strings.Contains(n, "bilingual") ||
+		strings.Contains(n, "trilingual") || strings.Contains(n, "polyglot") ||
+		strings.Contains(n, "omnilingual") {
+		return "Multilingual"
+	}
+	var langs []string
+	seen := map[string]bool{}
+	add := func(name string) {
+		if name != "" && !seen[name] {
+			seen[name] = true
+			langs = append(langs, name)
+		}
+	}
+	for _, tok := range strings.Split(strings.TrimSuffix(n, ".tar.bz2"), "-") {
+		add(langNames[tok])
+	}
+	// Full language words spelled out in some names (e.g. "-cantonese-").
+	for word, name := range map[string]string{
+		"cantonese": "Cantonese", "mandarin": "Chinese", "english": "English",
+		"chinese": "Chinese", "korean": "Korean", "japanese": "Japanese",
+		"russian": "Russian", "arabic": "Arabic", "spanish": "Spanish",
+		"french": "French", "german": "German", "vietnamese": "Vietnamese",
+		"thai": "Thai", "farsi": "Persian", "persian": "Persian",
+		"portuguese": "Portuguese", "italian": "Italian", "dutch": "Dutch",
+		"ukrainian": "Ukrainian", "polish": "Polish", "turkish": "Turkish",
+	} {
+		if strings.Contains(n, word) {
+			add(name)
+		}
+	}
+	switch {
+	case len(langs) == 0:
+		return ""
+	case len(langs) > 2:
+		return "Multilingual"
+	default:
+		return strings.Join(langs, " + ")
+	}
+}
+
+// curatedDescriptions maps a curated model's asset name to its quality blurb.
+var curatedDescriptions = func() map[string]string {
+	m := map[string]string{}
+	for _, v := range ModelVariants() {
+		m[v.AssetName] = v.Description
+	}
+	return m
+}()
+
+// EngineComponents identifies the resolved local-engine paths.
+type EngineComponents struct {
+	BinaryPath string // extracted sherpa-onnx-offline
+	ServerPath string // extracted sherpa-onnx-online-websocket-server
+	ModelPath  string // extracted model directory
+}
+
+// DownloadOptions configures EnsureLocalEngine.
+type DownloadOptions struct {
+	// DestRoot is where extracted engines/models live (e.g. ~/.config/zero/stt).
+	DestRoot string
+	// EngineVersion selects the sherpa-onnx release tag ("" → DefaultSherpaVersion;
+	// "latest" and any tag also work).
+	EngineVersion string
+	// HTTPClient is injectable for tests; nil uses a plain client.
+	HTTPClient *http.Client
+	// APIBase overrides the GitHub API base (tests). "" → api.github.com.
+	APIBase string
+	// Model selection (default: the Moonshine-tiny int8 batch model). Set these
+	// from a ModelVariant to download a different model.
+	ModelAssetName    string
+	ModelPinnedDigest string
+	ModelDirName      string
+	// ModelLabel is the friendly model name shown in progress ("Zipformer 20M").
+	ModelLabel string
+	// Progress receives live status strings for the UI, including a percentage
+	// while downloading (e.g. "Engine 45% · 57/126 MB").
+	Progress func(status string)
+	// platformKey overrides runtime detection (tests).
+	platformKey string
+	// skipPinned disables the pinned-digest cross-check (tests, which use fixture
+	// assets); the API-digest verification still runs.
+	skipPinned bool
+}
+
+// AutoDownloadSupported reports whether the current platform has a known engine
+// asset (so the F9 flow can offer the download). Termux/Android and unusual
+// arches install manually or use a cloud provider.
+func AutoDownloadSupported() bool {
+	_, ok := engineAssetSuffix[platformKey()]
+	return ok
+}
+
+func platformKey() string { return runtime.GOOS + "-" + runtime.GOARCH }
+
+// EnsureLocalEngine downloads (if absent) and verifies the sherpa-onnx engine and
+// the default model into DestRoot, returning the resolved paths. Idempotent: an
+// already-extracted, still-present engine/model is reused without re-downloading.
+// Every archive is SHA256-verified against the GitHub API digest before extraction.
+func EnsureLocalEngine(ctx context.Context, opts DownloadOptions) (EngineComponents, error) {
+	if strings.TrimSpace(opts.DestRoot) == "" {
+		return EngineComponents{}, fmt.Errorf("dictation download: DestRoot is required")
+	}
+	key := opts.platformKey
+	if key == "" {
+		key = platformKey()
+	}
+	suffix, ok := engineAssetSuffix[key]
+	if !ok {
+		return EngineComponents{}, &SetupError{
+			Tool: "sherpa-onnx auto-download",
+			Hint: fmt.Sprintf("no prebuilt engine is known for %s — install sherpa-onnx manually or use a cloud provider (see docs/dictation.md)", key),
+		}
+	}
+	version := strings.TrimSpace(opts.EngineVersion)
+	if version == "" {
+		version = DefaultSherpaVersion
+	}
+	progress := opts.Progress
+	if progress == nil {
+		progress = func(string) {}
+	}
+	client := opts.HTTPClient
+	if client == nil {
+		client = http.DefaultClient
+	}
+	apiBase := opts.APIBase
+	if apiBase == "" {
+		apiBase = defaultAPIBase
+	}
+
+	engineDir := filepath.Join(opts.DestRoot, "engine-"+version+"-"+key)
+	targetWindows := strings.HasPrefix(key, "windows-")
+	// Resolve through the tarball's flattened subdir so an ALREADY-extracted
+	// engine is found and not needlessly re-downloaded (the idempotency check).
+	binPath, serverPath := resolveEnginePaths(engineDir, targetWindows)
+	if !fileExists(binPath) {
+		pinned := ""
+		if version == DefaultSherpaVersion && !opts.skipPinned {
+			pinned = pinnedEngineDigest[key]
+		}
+		asset, err := resolveAsset(ctx, client, apiBase, version, "sherpa-onnx-", suffix)
+		if err != nil {
+			return EngineComponents{}, err
+		}
+		if err := downloadVerifyExtract(ctx, client, asset, pinned, false, "Engine", engineDir, progress); err != nil {
+			return EngineComponents{}, err
+		}
+		binPath, serverPath = resolveEnginePaths(engineDir, targetWindows)
+	}
+	if !fileExists(binPath) {
+		return EngineComponents{}, fmt.Errorf("dictation download: engine binary not found after extraction in %s", engineDir)
+	}
+
+	modelName := opts.ModelAssetName
+	if modelName == "" {
+		modelName = modelAssetName
+	}
+	modelDirName := opts.ModelDirName
+	if modelDirName == "" {
+		modelDirName = "model-moonshine-tiny-en-int8"
+	}
+	modelDir := filepath.Join(opts.DestRoot, modelDirName)
+	if !dirHasModel(modelDir) {
+		asset, err := resolveAsset(ctx, client, apiBase, modelReleaseTag, modelName, "")
+		if err != nil {
+			return EngineComponents{}, err
+		}
+		modelPinned := opts.ModelPinnedDigest
+		// Only fall back to the built-in digest for the DEFAULT model — a different
+		// (browse-listed) model must never be checked against the default's digest.
+		if modelPinned == "" && opts.ModelAssetName == "" {
+			modelPinned = pinnedModelDigest
+		}
+		if opts.skipPinned {
+			modelPinned = ""
+		}
+		modelLabel := opts.ModelLabel
+		if modelLabel == "" {
+			modelLabel = "Model"
+		}
+		// Models are data files from the official release: verify against a digest
+		// when we have one (curated/pinned or API-provided), else allow a TLS-only
+		// download (the model release predates GitHub's per-asset digests). The
+		// engine BINARY above never allows this — a native executable is always
+		// digest-verified.
+		if err := downloadVerifyExtract(ctx, client, asset, modelPinned, true, modelLabel, modelDir, progress); err != nil {
+			return EngineComponents{}, err
+		}
+	}
+	resolvedModel := modelDir
+	if !hasTokensFile(resolvedModel) {
+		if child, err := flattenSingleChild(modelDir); err == nil {
+			resolvedModel = child
+		}
+	}
+	if !hasTokensFile(resolvedModel) {
+		return EngineComponents{}, fmt.Errorf("dictation download: model files not found after extraction in %s", modelDir)
+	}
+	return EngineComponents{BinaryPath: binPath, ServerPath: serverPath, ModelPath: resolvedModel}, nil
+}
+
+type resolvedAsset struct {
+	url    string
+	sha256 string
+	size   int64
+	name   string
+}
+
+// resolveAsset queries the GitHub release for tag and returns the asset whose
+// name has the given prefix and suffix, plus its SHA256 digest and size.
+func resolveAsset(ctx context.Context, client *http.Client, apiBase, tag, namePrefix, nameSuffix string) (resolvedAsset, error) {
+	tagPath := "tags/" + tag
+	if tag == "" || tag == "latest" {
+		tagPath = "latest"
+	}
+	url := fmt.Sprintf("%s/repos/%s/releases/%s", strings.TrimRight(apiBase, "/"), sherpaRepo, tagPath)
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return resolvedAsset{}, err
+	}
+	req.Header.Set("Accept", "application/vnd.github+json")
+	resp, err := client.Do(req)
+	if err != nil {
+		return resolvedAsset{}, fmt.Errorf("resolving sherpa-onnx release %s: %w", tag, err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return resolvedAsset{}, fmt.Errorf("resolving sherpa-onnx release %s: GitHub API HTTP %d", tag, resp.StatusCode)
+	}
+	var release struct {
+		TagName string `json:"tag_name"`
+		Assets  []struct {
+			Name        string `json:"name"`
+			DownloadURL string `json:"browser_download_url"`
+			Digest      string `json:"digest"`
+			Size        int64  `json:"size"`
+		} `json:"assets"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&release); err != nil {
+		return resolvedAsset{}, fmt.Errorf("parsing sherpa-onnx release %s: %w", tag, err)
+	}
+	for _, a := range release.Assets {
+		if !strings.HasPrefix(a.Name, namePrefix) || !strings.HasSuffix(a.Name, nameSuffix) {
+			continue
+		}
+		// The API digest may be empty for older assets (GitHub only populates it for
+		// assets uploaded after ~2024 — the ASR models predate that). An empty
+		// digest is fine here; downloadVerifyExtract requires the API digest OR a
+		// pinned one and refuses only when neither exists.
+		digest := strings.TrimPrefix(a.Digest, "sha256:")
+		return resolvedAsset{url: a.DownloadURL, sha256: digest, size: a.Size, name: a.Name}, nil
+	}
+	return resolvedAsset{}, &SetupError{
+		Tool: "sherpa-onnx auto-download",
+		Hint: fmt.Sprintf("release %s has no asset matching %s*%s — try a different stt.engineVersion or install manually", tag, namePrefix, nameSuffix),
+	}
+}
+
+// downloadVerifyExtract fetches the asset to a temp file, verifies its SHA256
+// (against the API digest, and — when pinned is set — a cross-check that the
+// resolved digest equals the audited value), and extracts the tar.bz2. A
+// mismatch aborts before anything is extracted or run.
+func downloadVerifyExtract(ctx context.Context, client *http.Client, asset resolvedAsset, pinned string, allowUnverified bool, label, destDir string, progress func(string)) error {
+	// Determine the digest to verify against: the API digest and the pinned digest
+	// must agree when both exist; at least one must exist unless allowUnverified
+	// (models are data files from the official release — TLS-only is acceptable;
+	// a native executable never sets allowUnverified).
+	expected := asset.sha256
+	if pinned != "" {
+		if expected != "" && !strings.EqualFold(expected, pinned) {
+			return fmt.Errorf("dictation download: %s digest %s does not match the pinned known-good value %s — refusing (the release may have changed)", asset.name, asset.sha256, pinned)
+		}
+		expected = pinned
+	}
+	if expected == "" && !allowUnverified {
+		return fmt.Errorf("dictation download: no SHA256 available for %s (neither the GitHub API nor a pinned value) — refusing an unverifiable download", asset.name)
+	}
+	// Ensure the parent of destDir exists; the final destDir is created by
+	// the atomic rename at the end of the function.
+	if err := os.MkdirAll(filepath.Dir(destDir), 0o755); err != nil {
+		return err
+	}
+	// Stage the extraction into a sibling temp dir and only swap it into
+	// destDir on success. An interrupted run that left a truncated engine
+	// binary in destDir would otherwise pass fileExists() on the next start
+	// and break the local recorder silently.
+	stageDir, err := os.MkdirTemp(filepath.Dir(destDir), filepath.Base(destDir)+".stage-*")
+	if err != nil {
+		return err
+	}
+	cleanupStage := true
+	defer func() {
+		if cleanupStage {
+			_ = os.RemoveAll(stageDir)
+		}
+	}()
+
+	tmp, err := os.CreateTemp(filepath.Dir(destDir), "stt-dl-*.tar.bz2")
+	if err != nil {
+		return err
+	}
+	tmpPath := tmp.Name()
+	defer os.Remove(tmpPath)
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, asset.url, nil)
+	if err != nil {
+		tmp.Close()
+		return err
+	}
+	resp, err := client.Do(req)
+	if err != nil {
+		tmp.Close()
+		return fmt.Errorf("downloading %s: %w", asset.name, err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		tmp.Close()
+		return fmt.Errorf("downloading %s: HTTP %d", asset.name, resp.StatusCode)
+	}
+	hasher := sha256.New()
+	total := asset.size
+	if total <= 0 {
+		total = resp.ContentLength
+	}
+	src := io.Reader(resp.Body)
+	if total > 0 {
+		src = &progressReader{r: resp.Body, total: total, label: label, report: progress, lastPct: -1}
+	}
+	if _, err := io.Copy(io.MultiWriter(tmp, hasher), src); err != nil {
+		tmp.Close()
+		return fmt.Errorf("downloading %s: %w", asset.name, err)
+	}
+	if err := tmp.Close(); err != nil {
+		return err
+	}
+	got := hex.EncodeToString(hasher.Sum(nil))
+	if expected != "" && !strings.EqualFold(got, expected) {
+		return fmt.Errorf("dictation download: checksum mismatch for %s (want %s, got %s) — refusing to extract", asset.name, expected, got)
+	}
+	if err := extractTarBz2(tmpPath, stageDir, "Extracting "+label, progress); err != nil {
+		return err
+	}
+	// Remove any pre-existing destDir so Rename is atomic on the same
+	// filesystem (os.Rename refuses to overwrite a non-empty dir).
+	if err := os.RemoveAll(destDir); err != nil {
+		return fmt.Errorf("clearing previous %s install: %w", label, err)
+	}
+	if err := os.Rename(stageDir, destDir); err != nil {
+		return fmt.Errorf("promoting staged %s: %w", label, err)
+	}
+	cleanupStage = false
+	return nil
+}
+
+// progressReader reports download progress as a percentage on each whole-percent
+// change, formatted "<label> NN% · X/Y MB".
+type progressReader struct {
+	r       io.Reader
+	total   int64
+	read    int64
+	label   string
+	report  func(string)
+	lastPct int
+}
+
+func (p *progressReader) Read(b []byte) (int, error) {
+	n, err := p.r.Read(b)
+	p.read += int64(n)
+	if p.total > 0 {
+		pct := int(p.read * 100 / p.total)
+		if pct != p.lastPct {
+			p.lastPct = pct
+			p.report(fmt.Sprintf("%s %d%% · %d/%d MB", p.label, pct, p.read>>20, p.total>>20))
+		}
+	}
+	return n, err
+}
+
+// enginePaths builds the engine executable paths. The ".exe" suffix follows the
+// TARGET platform (the one the engine was downloaded for), not the host — they
+// match in production (you download your own platform), but keying off the target
+// keeps resolution correct when the two differ (e.g. a cross-platform test).
+func enginePaths(engineDir string, targetWindows bool) (bin, server string) {
+	ext := ""
+	if targetWindows {
+		ext = ".exe"
+	}
+	return filepath.Join(engineDir, "bin", "sherpa-onnx-offline"+ext),
+		filepath.Join(engineDir, "bin", "sherpa-onnx-online-websocket-server"+ext)
+}
+
+// resolveEnginePaths finds the executables, flattening the tarball's single
+// top-level directory when present.
+func resolveEnginePaths(engineDir string, targetWindows bool) (bin, server string) {
+	bin, server = enginePaths(engineDir, targetWindows)
+	if fileExists(bin) {
+		return bin, server
+	}
+	if child, err := flattenSingleChild(engineDir); err == nil && child != engineDir {
+		return enginePaths(child, targetWindows)
+	}
+	return bin, server
+}
+
+// extractTarBz2 unpacks a bzip2-compressed tar into destDir, guarding against
+// path-traversal entries. It reports extraction progress by how much of the
+// (compressed) archive it has consumed — the same MB scale as the download, so
+// "Extracting … 50% · 520/1041 MB" lines up with the download that preceded it.
+func extractTarBz2(archivePath, destDir, label string, progress func(string)) error {
+	f, err := os.Open(archivePath)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	var src io.Reader = f
+	if progress != nil {
+		if info, statErr := f.Stat(); statErr == nil && info.Size() > 0 {
+			src = &progressReader{r: f, total: info.Size(), label: label, report: progress, lastPct: -1}
+		}
+	}
+	tr := tar.NewReader(bzip2.NewReader(src))
+	destAbs, err := filepath.Abs(destDir)
+	if err != nil {
+		return err
+	}
+	for {
+		hdr, err := tr.Next()
+		if err == io.EOF {
+			return nil
+		}
+		if err != nil {
+			return err
+		}
+		target := filepath.Join(destDir, hdr.Name)
+		absTarget, err := filepath.Abs(target)
+		if err != nil {
+			return err
+		}
+		if absTarget != destAbs && !strings.HasPrefix(absTarget, destAbs+string(os.PathSeparator)) {
+			return fmt.Errorf("dictation download: archive entry %q escapes destination", hdr.Name)
+		}
+		switch hdr.Typeflag {
+		case tar.TypeDir:
+			if err := os.MkdirAll(target, 0o755); err != nil {
+				return err
+			}
+		case tar.TypeReg:
+			if err := os.MkdirAll(filepath.Dir(target), 0o755); err != nil {
+				return err
+			}
+			out, err := os.OpenFile(target, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, os.FileMode(hdr.Mode)&0o777)
+			if err != nil {
+				return err
+			}
+			if _, err := io.Copy(out, tr); err != nil {
+				out.Close()
+				return err
+			}
+			if err := out.Close(); err != nil {
+				return err
+			}
+		}
+	}
+}
+
+// flattenSingleChild returns the sole subdirectory of dir (the tarball's
+// top-level folder) when dir contains exactly one directory entry.
+func flattenSingleChild(dir string) (string, error) {
+	entries, err := os.ReadDir(dir)
+	if err != nil {
+		return "", err
+	}
+	var dirs []string
+	for _, e := range entries {
+		if e.IsDir() {
+			dirs = append(dirs, e.Name())
+		}
+	}
+	if len(dirs) == 1 {
+		return filepath.Join(dir, dirs[0]), nil
+	}
+	return dir, nil
+}
+
+// ModelDownloaded reports whether a model variant is already extracted under
+// destRoot (so the picker can mark it as installed). dirName is the variant's
+// DirName.
+func ModelDownloaded(destRoot, dirName string) bool {
+	if destRoot == "" || dirName == "" {
+		return false
+	}
+	return dirHasModel(filepath.Join(destRoot, dirName))
+}
+
+// EngineDownloaded reports whether the shared sherpa-onnx engine is already on
+// disk for this platform (one engine serves every model), so the picker can drop
+// the engine's size from a model's download total once it's been fetched.
+func EngineDownloaded(destRoot, version string) bool {
+	if destRoot == "" {
+		return false
+	}
+	if version == "" {
+		version = DefaultSherpaVersion
+	}
+	engineDir := filepath.Join(destRoot, "engine-"+version+"-"+platformKey())
+	bin, _ := resolveEnginePaths(engineDir, runtime.GOOS == "windows")
+	return fileExists(bin)
+}
+
+func dirHasModel(dir string) bool {
+	if hasTokensFile(dir) {
+		return true
+	}
+	if child, err := flattenSingleChild(dir); err == nil && child != dir {
+		return hasTokensFile(child)
+	}
+	return false
+}
+
+// hasTokensFile reports whether dir holds a sherpa tokens file — usually
+// "tokens.txt", but some families (Whisper) prefix it as "<model>-tokens.txt".
+func hasTokensFile(dir string) bool {
+	entries, err := os.ReadDir(dir)
+	if err != nil {
+		return false
+	}
+	for _, e := range entries {
+		if !e.IsDir() && strings.HasSuffix(e.Name(), "tokens.txt") {
+			return true
+		}
+	}
+	return false
+}
+
+func fileExists(path string) bool {
+	info, err := os.Stat(path)
+	return err == nil && !info.IsDir()
+}

internal/dictation/download_smoke_test.go

@@ -0,0 +1,52 @@
+package dictation
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+// TestEnsureLocalEngineRealDownload exercises the full auto-download against the
+// REAL k2-fsa/sherpa-onnx GitHub API (resolve → verify digest → extract → run).
+// It downloads ~130MB, so it is opt-in via ZERO_STT_DOWNLOAD_TEST=1.
+//
+//	ZERO_STT_DOWNLOAD_TEST=1 go test ./internal/dictation/ -run RealDownload -v -timeout 10m
+func TestEnsureLocalEngineRealDownload(t *testing.T) {
+	if os.Getenv("ZERO_STT_DOWNLOAD_TEST") == "" {
+		t.Skip("set ZERO_STT_DOWNLOAD_TEST=1 to run the real ~130MB download smoke test")
+	}
+	dest := t.TempDir()
+	comp, err := EnsureLocalEngine(context.Background(), DownloadOptions{
+		DestRoot: dest,
+		Progress: func(s string) { t.Logf("stage: %s", s) },
+	})
+	if err != nil {
+		t.Fatalf("EnsureLocalEngine: %v", err)
+	}
+	if !fileExists(comp.BinaryPath) || !fileExists(filepath.Join(comp.ModelPath, "tokens.txt")) {
+		t.Fatalf("missing components: %+v", comp)
+	}
+
+	// The downloaded engine + model must actually transcribe.
+	wav := filepath.Join(comp.ModelPath, "test_wavs", "0.wav")
+	if !fileExists(wav) {
+		t.Skipf("no bundled test wav at %s", wav)
+	}
+	audio, err := os.ReadFile(wav)
+	if err != nil {
+		t.Fatal(err)
+	}
+	tr, err := NewLocalTranscriber(LocalConfig{Binary: comp.BinaryPath, ModelPath: comp.ModelPath})
+	if err != nil {
+		t.Fatal(err)
+	}
+	text, err := tr.Transcribe(context.Background(), audio)
+	if err != nil {
+		t.Fatalf("Transcribe with downloaded engine: %v", err)
+	}
+	if text == "" {
+		t.Fatal("downloaded engine returned empty transcript")
+	}
+	t.Logf("downloaded-engine transcript: %q", text)
+}

internal/dictation/download_test.go

@@ -0,0 +1,245 @@
+package dictation
+
+import (
+	"context"
+	"encoding/base64"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+// Tiny tar.bz2 fixtures (generated in-repo): the engine has top/bin/sherpa-onnx-
+// offline + server; the model has top/tokens.txt.
+const (
+	engineTarB64 = "QlpoOTFBWSZTWW+fEfAAAW1/hMGRAIBAA/+AAgAgRH9v3+AAAQCoMAEYAYA00NGjEZANABoYYA00NGjEZANABoYIpE0TRoTGkA2poGgxqepl1H6w5anW3tY2OggUi1AW/d29pO0GLUoOtnQsrGFNowIEh0cImtQ9gyHqYH7unm+/wZSLXsBuBDDCfHiahCsGEgGL9/pUG+RQZo76xlaDIGKWDErPKuyhXYOlzJMG3iNa56kiluctzUqgZ2A1AGwgcB3jtB5PB7pYYlDHH8OvOznM6B6MHPRqa7sTE1vwDBc0LjmG4ah5F+YYaXHTZpGmcemWW1yMh1adhdrB6A3nAQP8XckU4UJBvnxHwA=="
+	engineSHA    = "97b5cb6a417705860f8940e1bf9ffec8cc60e8666a0d228cd60f1de7607d503d"
+	modelTarB64  = "QlpoOTFBWSZTWTtAoX4AANp/hMOQBIBAAf+AAAIQBHoJ3mAAAQAIMAC5sG1SNMhNqGmQwIyeKEagam1DQ0AAABFRT0T0mg0aeoDQHpH7Nzrs24wsbVW8hMQHClNI0LuLhKMGY4sEQi6N2qQWP1id8o1KtprGd4hll4uQkMGA1nFMXAwohEZOnIMIPQKQl2k0GbSGwkC0lJb2IWOQ57ETYbmxFGspaRp1QyT6q4sKj855st7GzOGj5eIwmWt6wRajEQl/F3JFOFCQO0Chfg=="
+	modelSHA     = "16c6b1dcb40f6b21c0de70bc1a8edab95375e4de90dac7c076fd2cc7a34fc59a"
+)
+
+// fakeReleaseServer serves the GitHub release API + asset bytes for the engine
+// and model, exercising resolveAsset + downloadVerifyExtract against a real HTTP
+// round-trip (with the real coder/websocket-free download path).
+func fakeReleaseServer(t *testing.T, engineDigest, modelDigest string) *httptest.Server {
+	t.Helper()
+	engineBytes, _ := base64.StdEncoding.DecodeString(engineTarB64)
+	modelBytes, _ := base64.StdEncoding.DecodeString(modelTarB64)
+	mux := http.NewServeMux()
+	base := ""
+	release := func(assetName, digest, dlPath string) string {
+		body, _ := json.Marshal(map[string]any{
+			"tag_name": "test",
+			"assets": []map[string]any{{
+				"name":                 assetName,
+				"browser_download_url": base + dlPath,
+				"digest":               "sha256:" + digest,
+				"size":                 123,
+			}},
+		})
+		return string(body)
+	}
+	var srv *httptest.Server
+	// Any release tag under this prefix resolves: asr-models → the model, every
+	// other tag → the engine (so the default-version pinned-check test works too).
+	mux.HandleFunc("/repos/k2-fsa/sherpa-onnx/releases/tags/", func(w http.ResponseWriter, r *http.Request) {
+		base = srv.URL
+		if strings.HasSuffix(r.URL.Path, "/asr-models") {
+			fmt.Fprint(w, release(modelAssetName, modelDigest, "/model.tar.bz2"))
+			return
+		}
+		fmt.Fprint(w, release("sherpa-onnx-test-linux-x64-shared-no-tts.tar.bz2", engineDigest, "/engine.tar.bz2"))
+	})
+	mux.HandleFunc("/engine.tar.bz2", func(w http.ResponseWriter, r *http.Request) { w.Write(engineBytes) })
+	mux.HandleFunc("/model.tar.bz2", func(w http.ResponseWriter, r *http.Request) { w.Write(modelBytes) })
+	srv = httptest.NewServer(mux)
+	base = srv.URL
+	t.Cleanup(srv.Close)
+	return srv
+}
+
+func TestResolveEnginePathsHonorsTargetPlatform(t *testing.T) {
+	// The engine binary name follows the TARGET platform, not the host: a Windows
+	// engine has ".exe", a Linux one doesn't. Resolution must find each regardless
+	// of the OS the test runs on (this is what makes the cross-platform download
+	// test pass on Windows CI).
+	for _, tc := range []struct {
+		name    string
+		target  bool
+		binName string
+	}{
+		{"linux target", false, "sherpa-onnx-offline"},
+		{"windows target", true, "sherpa-onnx-offline.exe"},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			dir := t.TempDir()
+			binDir := filepath.Join(dir, "bin")
+			if err := os.MkdirAll(binDir, 0o755); err != nil {
+				t.Fatal(err)
+			}
+			if err := os.WriteFile(filepath.Join(binDir, tc.binName), []byte("x"), 0o755); err != nil {
+				t.Fatal(err)
+			}
+			bin, _ := resolveEnginePaths(dir, tc.target)
+			if !fileExists(bin) {
+				t.Errorf("resolveEnginePaths(target-windows=%v) = %q; not found", tc.target, bin)
+			}
+			if !strings.HasSuffix(bin, tc.binName) {
+				t.Errorf("bin = %q, want suffix %q", bin, tc.binName)
+			}
+		})
+	}
+}
+
+func TestEnsureLocalEngineDownloadsAndExtracts(t *testing.T) {
+	srv := fakeReleaseServer(t, engineSHA, modelSHA)
+	dest := t.TempDir()
+	var stages []string
+	comp, err := EnsureLocalEngine(context.Background(), DownloadOptions{
+		DestRoot:      dest,
+		EngineVersion: "test",
+		APIBase:       srv.URL,
+		platformKey:   "linux-amd64",
+		skipPinned:    true,
+		Progress:      func(s string) { stages = append(stages, s) },
+	})
+	if err != nil {
+		t.Fatalf("EnsureLocalEngine: %v", err)
+	}
+	if !fileExists(comp.BinaryPath) || !strings.HasSuffix(comp.BinaryPath, "sherpa-onnx-offline") {
+		t.Errorf("binary path wrong: %q", comp.BinaryPath)
+	}
+	if !fileExists(comp.ServerPath) {
+		t.Errorf("server path missing: %q", comp.ServerPath)
+	}
+	if !fileExists(filepath.Join(comp.ModelPath, "tokens.txt")) {
+		t.Errorf("model tokens.txt missing under %q", comp.ModelPath)
+	}
+	// The extracted binary keeps its exec bit — Unix only; Windows has no
+	// executable permission bit, so os.FileMode never reports 0o100 there.
+	if runtime.GOOS != "windows" {
+		if info, err := os.Stat(comp.BinaryPath); err == nil && info.Mode()&0o100 == 0 {
+			t.Error("engine binary should be executable")
+		}
+	}
+	if len(stages) == 0 {
+		t.Error("expected progress stages")
+	}
+
+	// Idempotent: a second call reuses the extracted engine + model and downloads
+	// NOTHING (no progress stages) — the fix for re-downloading an already-present
+	// engine whose binary lives in the tarball's flattened subdir.
+	var stages2 []string
+	comp2, err := EnsureLocalEngine(context.Background(), DownloadOptions{
+		DestRoot: dest, EngineVersion: "test", APIBase: srv.URL, platformKey: "linux-amd64", skipPinned: true,
+		Progress: func(s string) { stages2 = append(stages2, s) },
+	})
+	if err != nil || comp2.BinaryPath != comp.BinaryPath {
+		t.Errorf("second call should reuse: %v / %q vs %q", err, comp2.BinaryPath, comp.BinaryPath)
+	}
+	if len(stages2) != 0 {
+		t.Errorf("a fully-cached second call must not download/extract anything, got stages: %v", stages2)
+	}
+}
+
+func TestEnsureLocalEngineRejectsChecksumMismatch(t *testing.T) {
+	// Serve the engine with a wrong digest → verification must refuse to extract.
+	srv := fakeReleaseServer(t, strings.Repeat("0", 64), modelSHA)
+	_, err := EnsureLocalEngine(context.Background(), DownloadOptions{
+		DestRoot: t.TempDir(), EngineVersion: "test", APIBase: srv.URL, platformKey: "linux-amd64", skipPinned: true,
+	})
+	if err == nil || !strings.Contains(err.Error(), "checksum mismatch") {
+		t.Fatalf("expected checksum-mismatch error, got %v", err)
+	}
+}
+
+func TestEnsureLocalEnginePinnedCrossCheckRefusesChangedRelease(t *testing.T) {
+	// Default version + a digest that doesn't match the pinned value → refuse,
+	// even though the download itself would verify against the API digest.
+	srv := fakeReleaseServer(t, engineSHA, modelSHA)
+	_, err := EnsureLocalEngine(context.Background(), DownloadOptions{
+		DestRoot:      t.TempDir(),
+		EngineVersion: DefaultSherpaVersion, // triggers the pinned cross-check
+		APIBase:       srv.URL,
+		platformKey:   "linux-amd64",
+		// skipPinned false: the pinned digest for linux-amd64 != engineSHA fixture.
+	})
+	if err == nil || !strings.Contains(err.Error(), "pinned known-good") {
+		t.Fatalf("expected pinned cross-check refusal, got %v", err)
+	}
+}
+
+func TestResolveAssetMissingDigestAllowed(t *testing.T) {
+	// An older asset with no API digest resolves fine (verification against a
+	// pinned value happens later); resolveAsset no longer refuses here.
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		json.NewEncoder(w).Encode(map[string]any{
+			"assets": []map[string]any{{"name": "x-linux-x64-shared-no-tts.tar.bz2", "browser_download_url": "http://x", "digest": ""}},
+		})
+	}))
+	defer srv.Close()
+	asset, err := resolveAsset(context.Background(), http.DefaultClient, srv.URL, "test", "x-", "linux-x64-shared-no-tts.tar.bz2")
+	if err != nil {
+		t.Fatalf("resolveAsset should tolerate a missing digest, got %v", err)
+	}
+	if asset.sha256 != "" {
+		t.Errorf("expected empty digest, got %q", asset.sha256)
+	}
+}
+
+func TestUnverifiableDownloadRefused(t *testing.T) {
+	// No API digest AND no pinned digest → refuse to download/extract.
+	srv := fakeReleaseServer(t, "", "") // both assets served with empty digest
+	_, err := EnsureLocalEngine(context.Background(), DownloadOptions{
+		DestRoot: t.TempDir(), EngineVersion: "test", APIBase: srv.URL, platformKey: "linux-amd64", skipPinned: true,
+	})
+	if err == nil || !strings.Contains(err.Error(), "unverifiable") {
+		t.Fatalf("expected refusal of an unverifiable download, got %v", err)
+	}
+}
+
+func TestProgressReaderReportsPercent(t *testing.T) {
+	data := make([]byte, 1000)
+	var last string
+	pr := &progressReader{r: bytesReader(data), total: 1000, label: "Engine", report: func(s string) { last = s }, lastPct: -1}
+	buf := make([]byte, 100)
+	for {
+		if _, err := pr.Read(buf); err != nil {
+			break
+		}
+	}
+	if !strings.Contains(last, "Engine") || !strings.Contains(last, "100%") {
+		t.Errorf("expected a final 'Engine 100%%' report, got %q", last)
+	}
+}
+
+func bytesReader(b []byte) *sliceReader { return &sliceReader{b: b} }
+
+type sliceReader struct {
+	b   []byte
+	pos int
+}
+
+func (s *sliceReader) Read(p []byte) (int, error) {
+	if s.pos >= len(s.b) {
+		return 0, io.EOF
+	}
+	n := copy(p, s.b[s.pos:])
+	s.pos += n
+	return n, nil
+}
+
+func TestUnsupportedPlatformSetupError(t *testing.T) {
+	_, err := EnsureLocalEngine(context.Background(), DownloadOptions{DestRoot: t.TempDir(), platformKey: "plan9-mips"})
+	var setupErr *SetupError
+	if !errors.As(err, &setupErr) {
+		t.Fatalf("want *SetupError for unsupported platform, got %v", err)
+	}
+}

internal/dictation/listmodels_test.go

@@ -0,0 +1,67 @@
+package dictation
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestListModelsFiltersAndFlags(t *testing.T) {
+	assets := []map[string]any{
+		{"name": "sherpa-onnx-streaming-zipformer-en-2023-06-26.tar.bz2", "size": 1 << 20, "digest": "sha256:abc"},
+		{"name": "sherpa-onnx-whisper-tiny.en.tar.bz2", "size": 2 << 20},
+		{"name": "sherpa-onnx-moonshine-tiny-en-int8.tar.bz2", "size": 3 << 20},                  // curated but not flagged recommended
+		{"name": "sherpa-onnx-streaming-zipformer-en-kroko-2025-08-06.tar.bz2", "size": 1 << 20}, // curated → recommended
+		{"name": "sherpa-onnx-paraformer-zh-2024-03-09.tar.bz2", "size": 4 << 20},
+		// Non-ASR tools that MUST be filtered out:
+		{"name": "sherpa-onnx-vad-silero.tar.bz2", "size": 1},
+		{"name": "vits-piper-en_US-amy.tar.bz2", "size": 1},
+		{"name": "sherpa-onnx-punct-en.tar.bz2", "size": 1},
+		{"name": "sherpa-onnx-kws-zipformer.tar.bz2", "size": 1},
+	}
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		json.NewEncoder(w).Encode(map[string]any{"id": 1, "assets": assets})
+	}))
+	defer srv.Close()
+
+	vs, err := ListModels(context.Background(), http.DefaultClient, srv.URL)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(vs) != 5 {
+		t.Fatalf("expected 5 transcription models (tools filtered), got %d", len(vs))
+	}
+	byID := map[string]ModelVariant{}
+	for _, v := range vs {
+		byID[v.ID] = v
+	}
+	if !byID["streaming-zipformer-en-2023-06-26"].Streaming {
+		t.Error("streaming model should be flagged Streaming")
+	}
+	if byID["whisper-tiny.en"].Streaming {
+		t.Error("whisper is batch, not streaming")
+	}
+	if !byID["streaming-zipformer-en-kroko-2025-08-06"].Recommended {
+		t.Error("a curated model flagged Recommended should be Recommended")
+	}
+	if byID["moonshine-tiny-en-int8"].Recommended {
+		t.Error("moonshine tiny is curated but no longer flagged Recommended (no star)")
+	}
+	if byID["paraformer-zh-2024-03-09"].Recommended {
+		t.Error("an uncurated model should not be Recommended")
+	}
+	// A curated model with no API digest still gets its pinned digest.
+	if byID["moonshine-tiny-en-int8"].Digest == "" {
+		t.Error("curated model should carry a pinned digest")
+	}
+	// An uncurated model with no API digest has an empty digest (TLS-only download).
+	if byID["whisper-tiny.en"].Digest != "" {
+		t.Error("uncurated model without an API digest should have an empty digest")
+	}
+	// The API-provided digest is used when present.
+	if byID["streaming-zipformer-en-2023-06-26"].Digest != "abc" {
+		t.Errorf("expected the API digest, got %q", byID["streaming-zipformer-en-2023-06-26"].Digest)
+	}
+}

internal/dictation/local_smoke_test.go

@@ -0,0 +1,40 @@
+package dictation
+
+import (
+	"context"
+	"os"
+	"testing"
+)
+
+// TestLocalTranscribeRealBinary exercises the full local batch path against a
+// REAL sherpa-onnx-offline binary and model — the manual smoke test §14 calls
+// out as not CI-able. Skipped unless both env vars point at a real install:
+//
+//	ZERO_STT_TEST_BINARY=/path/to/sherpa-onnx-offline \
+//	ZERO_STT_TEST_MODEL=/path/to/model-dir \
+//	ZERO_STT_TEST_WAV=/path/to/16k-mono.wav \
+//	go test ./internal/dictation/ -run TestLocalTranscribeRealBinary -v
+func TestLocalTranscribeRealBinary(t *testing.T) {
+	binary := os.Getenv("ZERO_STT_TEST_BINARY")
+	model := os.Getenv("ZERO_STT_TEST_MODEL")
+	wav := os.Getenv("ZERO_STT_TEST_WAV")
+	if binary == "" || model == "" || wav == "" {
+		t.Skip("set ZERO_STT_TEST_BINARY, ZERO_STT_TEST_MODEL, ZERO_STT_TEST_WAV to run the real-engine smoke test")
+	}
+	audio, err := os.ReadFile(wav)
+	if err != nil {
+		t.Fatalf("read wav: %v", err)
+	}
+	tr, err := NewLocalTranscriber(LocalConfig{Binary: binary, ModelPath: model})
+	if err != nil {
+		t.Fatalf("NewLocalTranscriber: %v", err)
+	}
+	text, err := tr.Transcribe(context.Background(), audio)
+	if err != nil {
+		t.Fatalf("Transcribe: %v", err)
+	}
+	if text == "" {
+		t.Fatal("real engine returned an empty transcript")
+	}
+	t.Logf("transcript: %q", text)
+}

internal/dictation/owner_unix.go

@@ -0,0 +1,24 @@
+//go:build !windows
+
+package dictation
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+)
+
+// checkAudioDirOwner rejects a dictation temp directory not owned by the
+// current user — on a shared /tmp another user could have pre-created the
+// path and would then control its lifetime. Mirrors
+// internal/tools/spill_owner_unix.go.
+func checkAudioDirOwner(info os.FileInfo) error {
+	stat, ok := info.Sys().(*syscall.Stat_t)
+	if !ok {
+		return nil
+	}
+	if int(stat.Uid) != os.Geteuid() {
+		return fmt.Errorf("dictation temp directory is owned by uid %d, not the current user", stat.Uid)
+	}
+	return nil
+}

internal/dictation/owner_windows.go

@@ -0,0 +1,12 @@
+//go:build windows
+
+package dictation
+
+import "os"
+
+// checkAudioDirOwner is a no-op on Windows: %TEMP% is per-user by default and
+// there is no portable uid to compare. The Lstat symlink/dir check in
+// audioSpillDir still applies. Mirrors internal/tools/spill_owner_windows.go.
+func checkAudioDirOwner(os.FileInfo) error {
+	return nil
+}

internal/dictation/recorder.go

@@ -0,0 +1,581 @@
+package dictation
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"math"
+	"os"
+	"os/exec"
+	"runtime"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+)
+
+// Recorder captures microphone audio. Start/Stop is the batch path (used on
+// Termux, and as the fallback everywhere); StartStreaming is the desktop-only
+// continuous-PCM path.
+type Recorder interface {
+	Start() error
+	// Stop ends a batch recording and returns the recorded audio bytes (WAV on
+	// desktop, M4A on Termux — SniffFormat distinguishes them).
+	Stop() ([]byte, error)
+	// StartStreaming begins continuous capture of raw little-endian PCM16 mono
+	// at the configured sample rate. Chunks arrive on the channel in ~50ms
+	// units; the channel closes when capture ends (stop called, max duration
+	// hit, or trailing-silence auto-stop). stop is idempotent.
+	StartStreaming() (chunks <-chan []byte, stop func() error, err error)
+}
+
+// Platform selects the audio-capture toolchain (§9 of the design doc).
+type Platform string
+
+const (
+	PlatformLinux       Platform = "linux"
+	PlatformDarwin      Platform = "darwin"
+	PlatformWindows     Platform = "windows"
+	PlatformTermux      Platform = "termux"
+	PlatformUnsupported Platform = ""
+)
+
+// DetectPlatform picks the capture toolchain for the current host. Termux is
+// detected by its environment (it reports GOOS=linux/android): TERMUX_VERSION
+// is exported to every Termux shell, and PREFIX carries the app package path.
+func DetectPlatform() Platform {
+	if os.Getenv("TERMUX_VERSION") != "" || strings.Contains(os.Getenv("PREFIX"), "com.termux") {
+		return PlatformTermux
+	}
+	switch runtime.GOOS {
+	case "linux":
+		return PlatformLinux
+	case "darwin":
+		return PlatformDarwin
+	case "windows":
+		return PlatformWindows
+	}
+	return PlatformUnsupported
+}
+
+// StreamingSupported reports whether the platform's capture tool can write raw
+// PCM to stdout. Termux's termux-microphone-record requires a regular output
+// file — a hard tool limitation, so Termux is batch-only permanently.
+func (p Platform) StreamingSupported() bool {
+	switch p {
+	case PlatformLinux, PlatformDarwin, PlatformWindows:
+		return true
+	}
+	return false
+}
+
+const (
+	// DefaultSampleRate is what the local engine and Deepgram consume.
+	// OpenAI Realtime's pcm16 requires 24kHz; its transcriber constructs the
+	// recorder accordingly.
+	DefaultSampleRate = 16000
+	// DefaultMaxDuration is the hard runaway-recording cap (§12), applied on
+	// every platform, batch and streaming. Overridable via
+	// stt.maxDurationSeconds.
+	DefaultMaxDuration = 5 * time.Minute
+
+	// Trailing-silence auto-stop (§9): stop ~2s after the signal falls below a
+	// 3% amplitude threshold — SoX's own `silence 1 0.1 3% 1 2.0 3%` numbers.
+	silenceThresholdPct = 3
+	silenceHold         = 2 * time.Second
+
+	chunkInterval = 50 * time.Millisecond
+	stopGrace     = 3 * time.Second
+)
+
+// RecorderOptions configures a Recorder. Zero values pick sensible defaults.
+type RecorderOptions struct {
+	Platform        Platform
+	SampleRate      int
+	MaxDuration     time.Duration
+	SilenceAutoStop bool
+	// WindowsAudioDevice is the dshow capture device name; auto-detected from
+	// `ffmpeg -list_devices` when empty.
+	WindowsAudioDevice string
+
+	// Test seams (unexported): fake the OS boundary, mirroring how
+	// internal/lsp/manager_test.go stubs serverStarter.
+	starter   processStarter
+	runOutput commandOutputRunner
+	tempDir   func() (string, error)
+	now       func() time.Time
+}
+
+func (o RecorderOptions) withDefaults() RecorderOptions {
+	if o.Platform == PlatformUnsupported {
+		o.Platform = DetectPlatform()
+	}
+	if o.SampleRate <= 0 {
+		o.SampleRate = DefaultSampleRate
+	}
+	if o.MaxDuration <= 0 {
+		o.MaxDuration = DefaultMaxDuration
+	}
+	if o.starter == nil {
+		o.starter = startProcess
+	}
+	if o.runOutput == nil {
+		o.runOutput = runCommandOutput
+	}
+	if o.tempDir == nil {
+		o.tempDir = audioSpillDir
+	}
+	if o.now == nil {
+		o.now = time.Now
+	}
+	return o
+}
+
+// NewRecorder builds the platform recorder. Construction is cheap and
+// side-effect free; tools are only exec'd on Start/StartStreaming.
+func NewRecorder(opts RecorderOptions) Recorder {
+	o := opts.withDefaults()
+	return &recorder{opts: o}
+}
+
+type recorder struct {
+	opts RecorderOptions
+
+	mu        sync.Mutex
+	proc      processHandle
+	filePath  string
+	recording bool
+}
+
+var errAlreadyRecording = errors.New("a recording is already in progress")
+
+// Start begins a batch (record-to-file) capture.
+func (r *recorder) Start() error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	if r.recording {
+		return errAlreadyRecording
+	}
+	if r.opts.Platform == PlatformUnsupported {
+		return fmt.Errorf("dictation is not supported on %s", runtime.GOOS)
+	}
+
+	dir, err := r.opts.tempDir()
+	if err != nil {
+		return fmt.Errorf("preparing dictation temp dir: %w", err)
+	}
+	ext := ".wav"
+	if r.opts.Platform == PlatformTermux {
+		ext = ".m4a"
+	}
+	tmp, err := os.CreateTemp(dir, "rec-*"+ext)
+	if err != nil {
+		return fmt.Errorf("creating dictation temp file: %w", err)
+	}
+	path := tmp.Name()
+	_ = tmp.Close()
+
+	if r.opts.Platform == PlatformTermux {
+		// termux-microphone-record starts the recording in the Termux:API
+		// companion app and exits immediately; there is no long-lived process
+		// to hold. Stop is a separate `-q` invocation.
+		ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+		defer cancel()
+		out, err := r.opts.runOutput(ctx, "termux-microphone-record",
+			"-l", strconv.Itoa(maxSeconds(r.opts.MaxDuration)), "-f", path)
+		if err != nil {
+			_ = os.Remove(path)
+			return startError("termux-microphone-record", r.opts.Platform, err, out)
+		}
+		r.filePath = path
+		r.recording = true
+		return nil
+	}
+
+	spec, err := batchCommand(r.opts, path)
+	if err != nil {
+		_ = os.Remove(path)
+		return err
+	}
+	proc, _, err := r.opts.starter(spec)
+	if err != nil {
+		_ = os.Remove(path)
+		return startError(spec.name, r.opts.Platform, err, nil)
+	}
+	r.proc = proc
+	r.filePath = path
+	r.recording = true
+	return nil
+}
+
+// Stop ends a batch capture, reads the recorded file, deletes it, and returns
+// the audio bytes.
+func (r *recorder) Stop() ([]byte, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	if !r.recording {
+		return nil, errors.New("no recording in progress")
+	}
+	proc, path := r.proc, r.filePath
+	// Termux: Start's termux-microphone-record branch leaves r.proc nil because
+	// there's no long-lived process to hold (Stop is a separate `-q` invocation
+	// via runOutput). Treat that as legitimate; only reject a nil proc that
+	// came from StartStreaming (which owns its process via the returned
+	// closure).
+	if proc == nil && r.opts.Platform != PlatformTermux {
+		return nil, errors.New("recording was started with StartStreaming; call the stop closure returned from StartStreaming instead of Stop()")
+	}
+	r.proc, r.filePath, r.recording = nil, "", false
+	defer os.Remove(path)
+
+	if r.opts.Platform == PlatformTermux {
+		ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+		defer cancel()
+		if out, err := r.opts.runOutput(ctx, "termux-microphone-record", "-q"); err != nil {
+			return nil, fmt.Errorf("stopping termux recording: %w (%s)", err, strings.TrimSpace(string(out)))
+		}
+		return readRecordingWithRetry(path, r.opts.now)
+	}
+
+	if err := proc.StopGracefully(); err != nil {
+		_ = proc.Kill()
+	}
+	// A signal-terminated capture tool reports a non-zero exit — expected, not
+	// an error. The recorded file's contents are the real success signal.
+	_ = waitWithTimeout(proc, stopGrace)
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil, fmt.Errorf("reading recorded audio: %w", err)
+	}
+	if len(data) == 0 {
+		return nil, errors.New("no audio was captured (is the microphone available?)")
+	}
+	return data, nil
+}
+
+// readRecordingWithRetry reads the Termux recording, retrying briefly: the
+// companion app finalizes the file asynchronously after `-q` returns.
+func readRecordingWithRetry(path string, now func() time.Time) ([]byte, error) {
+	deadline := now().Add(2 * time.Second)
+	for {
+		data, err := os.ReadFile(path)
+		if err == nil && len(data) > 0 {
+			return data, nil
+		}
+		if now().After(deadline) {
+			if err != nil {
+				return nil, fmt.Errorf("reading recorded audio: %w", err)
+			}
+			return nil, errors.New("no audio was captured (check Termux:API app and microphone permission)")
+		}
+		time.Sleep(50 * time.Millisecond)
+	}
+}
+
+// batchCommand builds the record-to-file argv for desktop platforms (§9).
+// The max-duration cap is enforced by the tool itself so a runaway recording
+// ends even if Zero never calls Stop.
+func batchCommand(opts RecorderOptions, path string) (commandSpec, error) {
+	rate := strconv.Itoa(opts.SampleRate)
+	maxSec := strconv.Itoa(maxSeconds(opts.MaxDuration))
+	switch opts.Platform {
+	case PlatformLinux:
+		return commandSpec{
+			name: "arecord",
+			args: []string{"-q", "-f", "S16_LE", "-r", rate, "-c", "1", "-t", "wav", "-d", maxSec, path},
+		}, nil
+	case PlatformDarwin:
+		args := []string{"-q", "-d", "-r", rate, "-c", "1", "-b", "16", "-e", "signed-integer", path, "trim", "0", maxSec}
+		if opts.SilenceAutoStop {
+			// SoX's built-in trailing-silence auto-stop: end ~2s after the
+			// signal falls below 3% amplitude. A backstop for a forgotten
+			// manual stop, not VAD — recording still starts on an explicit key.
+			args = append(args, "silence", "1", "0.1", "3%", "1", "2.0", "3%")
+		}
+		return commandSpec{name: "sox", args: args}, nil
+	case PlatformWindows:
+		device := opts.WindowsAudioDevice
+		if device == "" {
+			detected, err := detectWindowsAudioDevice(opts.runOutput)
+			if err != nil {
+				return commandSpec{}, err
+			}
+			device = detected
+		}
+		return commandSpec{
+			name: "ffmpeg",
+			args: []string{"-hide_banner", "-loglevel", "error", "-f", "dshow", "-i", "audio=" + device,
+				"-ac", "1", "-ar", rate, "-c:a", "pcm_s16le", "-t", maxSec, "-y", path},
+			stopViaStdin: "q",
+		}, nil
+	}
+	return commandSpec{}, fmt.Errorf("no batch capture tool for platform %q", opts.Platform)
+}
+
+// streamCommand builds the raw-PCM-to-stdout argv for desktop platforms (§9).
+// Same tools as batch, invoked with their stdout flag — Termux has no stdout
+// mode, which is why it is batch-only.
+func streamCommand(opts RecorderOptions) (commandSpec, error) {
+	rate := strconv.Itoa(opts.SampleRate)
+	switch opts.Platform {
+	case PlatformLinux:
+		return commandSpec{
+			name:       "arecord",
+			args:       []string{"-q", "-t", "raw", "-f", "S16_LE", "-r", rate, "-c", "1", "-"},
+			wantStdout: true,
+		}, nil
+	case PlatformDarwin:
+		return commandSpec{
+			name:       "sox",
+			args:       []string{"-q", "-d", "-t", "raw", "-r", rate, "-e", "signed", "-b", "16", "-c", "1", "-"},
+			wantStdout: true,
+		}, nil
+	case PlatformWindows:
+		device := opts.WindowsAudioDevice
+		if device == "" {
+			detected, err := detectWindowsAudioDevice(opts.runOutput)
+			if err != nil {
+				return commandSpec{}, err
+			}
+			device = detected
+		}
+		return commandSpec{
+			name: "ffmpeg",
+			args: []string{"-hide_banner", "-loglevel", "error", "-f", "dshow", "-i", "audio=" + device,
+				"-ac", "1", "-ar", rate, "-f", "s16le", "-"},
+			wantStdout:   true,
+			stopViaStdin: "q",
+		}, nil
+	}
+	return commandSpec{}, fmt.Errorf("streaming capture is not supported on platform %q", opts.Platform)
+}
+
+// StartStreaming begins continuous PCM capture with the §12 safety nets: a
+// hard max-duration cap and Go-side trailing-silence auto-stop (the streaming
+// analog of SoX's silence effect — we see the samples, so we measure them).
+func (r *recorder) StartStreaming() (<-chan []byte, func() error, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	if r.recording {
+		return nil, nil, errAlreadyRecording
+	}
+	spec, err := streamCommand(r.opts)
+	if err != nil {
+		return nil, nil, err
+	}
+	proc, stdout, err := r.opts.starter(spec)
+	if err != nil {
+		return nil, nil, startError(spec.name, r.opts.Platform, err, nil)
+	}
+	if stdout == nil {
+		_ = proc.Kill()
+		return nil, nil, errors.New("capture process has no stdout pipe")
+	}
+	r.recording = true
+
+	chunkBytes := chunkSizeBytes(r.opts.SampleRate)
+	chunks := make(chan []byte, 8)
+	done := make(chan struct{})
+	var stopOnce sync.Once
+	stop := func() error {
+		stopOnce.Do(func() {
+			close(done)
+			if err := proc.StopGracefully(); err != nil {
+				_ = proc.Kill()
+			}
+			_ = waitWithTimeout(proc, stopGrace)
+			_ = stdout.Close()
+			r.mu.Lock()
+			r.recording = false
+			r.mu.Unlock()
+		})
+		return nil
+	}
+
+	// Max-duration cap: streaming has no tool-side -d/-t equivalent that also
+	// flushes stdout cleanly everywhere, so the cap runs on our side of the pipe.
+	capTimer := time.AfterFunc(r.opts.MaxDuration, func() { _ = stop() })
+
+	go func() {
+		defer close(chunks)
+		defer capTimer.Stop()
+		// Tear down on ANY exit — including the capture process ending on its own
+		// (EOF/crash), which the loop below returns on without going through an
+		// explicit stop(). stop() is idempotent (sync.Once), so this is safe even
+		// when the session was already stopped externally; it clears r.recording and
+		// closes proc/stdout so a self-terminating device doesn't wedge the recorder.
+		defer func() { _ = stop() }()
+		threshold := int16(32767 * silenceThresholdPct / 100)
+		silentChunks, speechSeen := 0, false
+		silenceLimit := int(silenceHold / chunkInterval)
+		for {
+			buf := make([]byte, chunkBytes)
+			n, err := readFullOrEOF(stdout, buf)
+			if n > 0 {
+				chunk := buf[:n]
+				if r.opts.SilenceAutoStop {
+					if chunkPeak(chunk) >= threshold {
+						speechSeen = true
+						silentChunks = 0
+					} else if speechSeen {
+						silentChunks++
+						if silentChunks >= silenceLimit {
+							go func() { _ = stop() }()
+						}
+					}
+				}
+				select {
+				case chunks <- chunk:
+				case <-done:
+					return
+				}
+			}
+			if err != nil {
+				return
+			}
+		}
+	}()
+	return chunks, stop, nil
+}
+
+// chunkSizeBytes is 50ms of PCM16 mono at the given rate — small chunks mean
+// faster time-to-first-partial (§6a).
+func chunkSizeBytes(sampleRate int) int {
+	return sampleRate * 2 / int(time.Second/chunkInterval)
+}
+
+// readFullOrEOF fills buf from r, returning what it read and any terminal
+// error. A short final read (pipe closing mid-chunk) still returns its bytes.
+func readFullOrEOF(r interface{ Read([]byte) (int, error) }, buf []byte) (int, error) {
+	total := 0
+	for total < len(buf) {
+		n, err := r.Read(buf[total:])
+		total += n
+		if err != nil {
+			return total, err
+		}
+	}
+	return total, nil
+}
+
+// chunkPeak returns the loudest absolute sample in a little-endian PCM16 chunk.
+func chunkPeak(chunk []byte) int16 {
+	var peak int16
+	for i := 0; i+1 < len(chunk); i += 2 {
+		s := int16(uint16(chunk[i]) | uint16(chunk[i+1])<<8)
+		if s == -32768 {
+			return 32767
+		}
+		if s < 0 {
+			s = -s
+		}
+		if s > peak {
+			peak = s
+		}
+	}
+	return peak
+}
+
+// levelFloorDB and levelCeilDB bound the RMS→meter mapping. Speech RMS is small
+// (roughly -45 dBFS quiet to -15 dBFS loud), so a LINEAR scale barely moves the
+// bars — a dB (logarithmic) scale, like real audio meters, is what makes normal
+// speech span the meter.
+const (
+	levelFloorDB = -50.0 // ≈ near-silence → empty
+	levelCeilDB  = -15.0 // loud speech → full
+)
+
+// ChunkLevel returns a perceptual 0..1 loudness for a little-endian PCM16 chunk,
+// driving the live recording waveform from the actual microphone input. It uses
+// an RMS→dBFS→linear mapping over [levelFloorDB, levelCeilDB].
+func ChunkLevel(chunk []byte) float64 {
+	var sumSq float64
+	n := 0
+	for i := 0; i+1 < len(chunk); i += 2 {
+		s := int16(uint16(chunk[i]) | uint16(chunk[i+1])<<8)
+		f := float64(s) / 32768.0
+		sumSq += f * f
+		n++
+	}
+	if n == 0 {
+		return 0
+	}
+	rms := math.Sqrt(sumSq / float64(n))
+	if rms <= 0 {
+		return 0
+	}
+	db := 20 * math.Log10(rms) // dBFS (negative)
+	level := (db - levelFloorDB) / (levelCeilDB - levelFloorDB)
+	if level < 0 {
+		level = 0
+	}
+	if level > 1 {
+		level = 1
+	}
+	return level
+}
+
+func maxSeconds(d time.Duration) int {
+	sec := int(d / time.Second)
+	if sec < 1 {
+		sec = 1
+	}
+	return sec
+}
+
+// detectWindowsAudioDevice picks the first dshow audio capture device from
+// `ffmpeg -list_devices`. dshow has no "default" alias, so a concrete device
+// name is required; stt.windowsAudioDevice overrides the auto-pick.
+func detectWindowsAudioDevice(runOutput commandOutputRunner) (string, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	out, _ := runOutput(ctx, "ffmpeg", "-hide_banner", "-list_devices", "true", "-f", "dshow", "-i", "dummy")
+	// Listing always "fails" (dummy isn't a real input); the device table is
+	// in the output regardless. Lines look like: [dshow @ ...] "Mic name" (audio)
+	for _, line := range strings.Split(string(out), "\n") {
+		if !strings.Contains(line, "(audio)") {
+			continue
+		}
+		start := strings.Index(line, `"`)
+		if start < 0 {
+			continue
+		}
+		rest := line[start+1:]
+		end := strings.Index(rest, `"`)
+		if end <= 0 {
+			continue
+		}
+		return rest[:end], nil
+	}
+	return "", &SetupError{
+		Tool: "ffmpeg",
+		Hint: "no dshow audio capture device found — set stt.windowsAudioDevice to your microphone's name (list with: ffmpeg -list_devices true -f dshow -i dummy)",
+	}
+}
+
+// startError maps a failed capture-tool launch to setup guidance: a missing
+// binary is an expected unconfigured state (matching internal/lsp's
+// missing-server philosophy), not an internal error.
+func startError(tool string, platform Platform, err error, output []byte) error {
+	if errors.Is(err, exec.ErrNotFound) {
+		return &SetupError{Tool: tool, Hint: installHint(platform)}
+	}
+	if len(output) > 0 {
+		return fmt.Errorf("starting %s: %w (%s)", tool, err, strings.TrimSpace(string(output)))
+	}
+	return fmt.Errorf("starting %s: %w", tool, err)
+}
+
+func installHint(platform Platform) string {
+	switch platform {
+	case PlatformLinux:
+		return "install alsa-utils to enable dictation (e.g. sudo dnf install alsa-utils / sudo apt install alsa-utils)"
+	case PlatformDarwin:
+		return "install sox to enable dictation (brew install sox)"
+	case PlatformWindows:
+		return "install ffmpeg and ensure it is on PATH to enable dictation"
+	case PlatformTermux:
+		return "run `pkg install termux-api` and install the Termux:API companion app to enable dictation"
+	}
+	return "dictation is not supported on this platform"
+}

internal/dictation/recorder_test.go

@@ -0,0 +1,501 @@
+package dictation
+
+import (
+	"bytes"
+	"context"
+	"encoding/binary"
+	"errors"
+	"io"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"sync"
+	"testing"
+	"time"
+)
+
+// fakeProcess is a processHandle whose stdout is driven from an in-memory
+// buffer, mirroring how internal/lsp/manager_test.go stubs its subprocess over
+// in-memory pipes rather than spawning a real one.
+type fakeProcess struct {
+	stopped   bool
+	killed    bool
+	waitErr   error
+	stopErr   error
+	closeOnce sync.Once
+	done      chan struct{}
+}
+
+func newFakeProcess() *fakeProcess { return &fakeProcess{done: make(chan struct{})} }
+
+func (f *fakeProcess) StopGracefully() error {
+	f.stopped = true
+	f.closeOnce.Do(func() { close(f.done) })
+	return f.stopErr
+}
+func (f *fakeProcess) Wait() error {
+	<-f.done
+	return f.waitErr
+}
+func (f *fakeProcess) Kill() error {
+	f.killed = true
+	f.closeOnce.Do(func() { close(f.done) })
+	return nil
+}
+
+// captured records the last spec a starter was asked to launch, so tests can
+// assert the exact discrete argv per platform.
+type captured struct {
+	spec commandSpec
+}
+
+// fileWritingStarter simulates a record-to-file batch tool: on Start it writes
+// fixture bytes to the output path (last positional arg for arecord/sox, or the
+// -y target for ffmpeg) and returns a process that "records" until stopped.
+func fileWritingStarter(t *testing.T, cap *captured, fixture []byte) processStarter {
+	t.Helper()
+	return func(spec commandSpec) (processHandle, io.ReadCloser, error) {
+		cap.spec = spec
+		path := outputPath(spec)
+		if path == "" {
+			t.Fatalf("could not determine output path from argv: %v", spec.args)
+		}
+		if err := os.WriteFile(path, fixture, 0o600); err != nil {
+			t.Fatalf("fixture write: %v", err)
+		}
+		return newFakeProcess(), nil, nil
+	}
+}
+
+func outputPath(spec commandSpec) string {
+	for i, a := range spec.args {
+		if a == "-y" && i+1 < len(spec.args) {
+			return spec.args[i+1]
+		}
+	}
+	// arecord/sox: the path is the last arg (sox appends trim/silence effects
+	// after it, so scan from the front for the first existing-dir target).
+	last := spec.args[len(spec.args)-1]
+	if filepath.IsAbs(last) {
+		return last
+	}
+	for _, a := range spec.args {
+		if filepath.IsAbs(a) && filepath.Ext(a) != "" {
+			return a
+		}
+	}
+	return ""
+}
+
+func wavFixture() []byte {
+	// Minimal valid RIFF/WAVE header + a little data, enough for SniffFormat.
+	var b bytes.Buffer
+	b.WriteString("RIFF")
+	binary.Write(&b, binary.LittleEndian, uint32(36))
+	b.WriteString("WAVE")
+	b.WriteString("fmt ")
+	binary.Write(&b, binary.LittleEndian, uint32(16))
+	b.Write(make([]byte, 16))
+	b.WriteString("data")
+	binary.Write(&b, binary.LittleEndian, uint32(4))
+	b.Write([]byte{1, 2, 3, 4})
+	return b.Bytes()
+}
+
+func testTempDir(t *testing.T) func() (string, error) {
+	dir := t.TempDir()
+	return func() (string, error) { return dir, nil }
+}
+
+func TestBatchRecordLinuxArgv(t *testing.T) {
+	cap := &captured{}
+	fixture := wavFixture()
+	r := NewRecorder(RecorderOptions{
+		Platform: PlatformLinux,
+		starter:  fileWritingStarter(t, cap, fixture),
+		tempDir:  testTempDir(t),
+	})
+	if err := r.Start(); err != nil {
+		t.Fatalf("Start: %v", err)
+	}
+	got, err := r.Stop()
+	if err != nil {
+		t.Fatalf("Stop: %v", err)
+	}
+	if !bytes.Equal(got, fixture) {
+		t.Fatalf("audio mismatch: got %d bytes", len(got))
+	}
+	if cap.spec.name != "arecord" {
+		t.Errorf("tool = %q, want arecord", cap.spec.name)
+	}
+	assertArgs(t, cap.spec.args, "-f", "S16_LE")
+	assertArgs(t, cap.spec.args, "-r", "16000")
+	assertArgs(t, cap.spec.args, "-c", "1")
+}
+
+func TestBatchRecordDarwinArgv(t *testing.T) {
+	cap := &captured{}
+	r := NewRecorder(RecorderOptions{
+		Platform:        PlatformDarwin,
+		SilenceAutoStop: true,
+		starter:         fileWritingStarter(t, cap, wavFixture()),
+		tempDir:         testTempDir(t),
+	})
+	if err := r.Start(); err != nil {
+		t.Fatalf("Start: %v", err)
+	}
+	if _, err := r.Stop(); err != nil {
+		t.Fatalf("Stop: %v", err)
+	}
+	if cap.spec.name != "sox" {
+		t.Errorf("tool = %q, want sox", cap.spec.name)
+	}
+	if !containsSubseq(cap.spec.args, []string{"silence", "1", "0.1", "3%", "1", "2.0", "3%"}) {
+		t.Errorf("expected SoX silence auto-stop effect in argv: %v", cap.spec.args)
+	}
+}
+
+func TestBatchRecordWindowsArgv(t *testing.T) {
+	cap := &captured{}
+	r := NewRecorder(RecorderOptions{
+		Platform:           PlatformWindows,
+		WindowsAudioDevice: "Microphone (Realtek)",
+		starter:            fileWritingStarter(t, cap, wavFixture()),
+		tempDir:            testTempDir(t),
+	})
+	if err := r.Start(); err != nil {
+		t.Fatalf("Start: %v", err)
+	}
+	if _, err := r.Stop(); err != nil {
+		t.Fatalf("Stop: %v", err)
+	}
+	if cap.spec.name != "ffmpeg" {
+		t.Errorf("tool = %q, want ffmpeg", cap.spec.name)
+	}
+	assertArgs(t, cap.spec.args, "-i", "audio=Microphone (Realtek)")
+	if cap.spec.stopViaStdin != "q" {
+		t.Errorf("ffmpeg should stop via stdin 'q', got %q", cap.spec.stopViaStdin)
+	}
+}
+
+func TestBatchRecordTermuxUsesCommandRunner(t *testing.T) {
+	dir := t.TempDir()
+	var calls [][]string
+	runOutput := func(_ context.Context, name string, args ...string) ([]byte, error) {
+		calls = append(calls, append([]string{name}, args...))
+		if len(args) > 0 && args[0] == "-l" {
+			// The -f target is the last arg; write the fixture there.
+			path := args[len(args)-1]
+			_ = os.WriteFile(path, m4aFixture(), 0o600)
+		}
+		return nil, nil
+	}
+	r := NewRecorder(RecorderOptions{
+		Platform: PlatformTermux,
+		starter: func(commandSpec) (processHandle, io.ReadCloser, error) {
+			t.Fatal("termux must not use the process starter")
+			return nil, nil, nil
+		},
+		runOutput: runOutput,
+		tempDir:   func() (string, error) { return dir, nil },
+	})
+	if err := r.Start(); err != nil {
+		t.Fatalf("Start: %v", err)
+	}
+	got, err := r.Stop()
+	if err != nil {
+		t.Fatalf("Stop: %v", err)
+	}
+	if SniffFormat(got) != FormatM4A {
+		t.Errorf("expected m4a audio, got format %q", SniffFormat(got))
+	}
+	if len(calls) != 2 || calls[0][0] != "termux-microphone-record" || calls[1][len(calls[1])-1] != "-q" {
+		t.Errorf("unexpected termux calls: %v", calls)
+	}
+}
+
+func TestStartMissingBinaryReturnsSetupError(t *testing.T) {
+	r := NewRecorder(RecorderOptions{
+		Platform: PlatformLinux,
+		starter: func(commandSpec) (processHandle, io.ReadCloser, error) {
+			return nil, nil, exec.ErrNotFound
+		},
+		tempDir: testTempDir(t),
+	})
+	err := r.Start()
+	var setupErr *SetupError
+	if !errors.As(err, &setupErr) {
+		t.Fatalf("want *SetupError for missing binary, got %v", err)
+	}
+	if setupErr.Tool != "arecord" {
+		t.Errorf("SetupError.Tool = %q, want arecord", setupErr.Tool)
+	}
+}
+
+func TestDoubleStartRejected(t *testing.T) {
+	r := NewRecorder(RecorderOptions{
+		Platform: PlatformLinux,
+		starter:  fileWritingStarter(t, &captured{}, wavFixture()),
+		tempDir:  testTempDir(t),
+	})
+	if err := r.Start(); err != nil {
+		t.Fatalf("Start: %v", err)
+	}
+	if err := r.Start(); !errors.Is(err, errAlreadyRecording) {
+		t.Errorf("second Start should be rejected, got %v", err)
+	}
+}
+
+func TestStreamingChunksAndStop(t *testing.T) {
+	// 300ms of PCM16 @16kHz = 6 chunks of 50ms. Feed a fixed buffer, then EOF.
+	pcm := make([]byte, chunkSizeBytes(16000)*6)
+	starter := func(spec commandSpec) (processHandle, io.ReadCloser, error) {
+		if !spec.wantStdout {
+			t.Fatal("streaming spec must request stdout")
+		}
+		return newFakeProcess(), io.NopCloser(bytes.NewReader(pcm)), nil
+	}
+	r := NewRecorder(RecorderOptions{
+		Platform: PlatformLinux,
+		starter:  starter,
+		tempDir:  testTempDir(t),
+	})
+	chunks, stop, err := r.StartStreaming()
+	if err != nil {
+		t.Fatalf("StartStreaming: %v", err)
+	}
+	var total int
+	for c := range chunks {
+		total += len(c)
+	}
+	_ = stop()
+	if total != len(pcm) {
+		t.Errorf("streamed %d bytes, want %d", total, len(pcm))
+	}
+}
+
+func TestStreamingStopIdempotent(t *testing.T) {
+	// A blocking reader so the capture goroutine parks until we stop it.
+	pr, pw := io.Pipe()
+	defer pw.Close()
+	starter := func(commandSpec) (processHandle, io.ReadCloser, error) {
+		return newFakeProcess(), pr, nil
+	}
+	r := NewRecorder(RecorderOptions{Platform: PlatformLinux, starter: starter, tempDir: testTempDir(t)})
+	chunks, stop, err := r.StartStreaming()
+	if err != nil {
+		t.Fatalf("StartStreaming: %v", err)
+	}
+	if err := stop(); err != nil {
+		t.Fatalf("stop: %v", err)
+	}
+	if err := stop(); err != nil {
+		t.Fatalf("second stop should be a no-op, got %v", err)
+	}
+	// Draining the channel must terminate now that we've stopped.
+	drained := make(chan struct{})
+	go func() {
+		for range chunks {
+		}
+		close(drained)
+	}()
+	select {
+	case <-drained:
+	case <-time.After(2 * time.Second):
+		t.Fatal("chunks channel did not close after stop")
+	}
+}
+
+func TestBatchMaxDurationCapInArgv(t *testing.T) {
+	cap := &captured{}
+	r := NewRecorder(RecorderOptions{
+		Platform:    PlatformLinux,
+		MaxDuration: 90 * time.Second,
+		starter:     fileWritingStarter(t, cap, wavFixture()),
+		tempDir:     testTempDir(t),
+	})
+	if err := r.Start(); err != nil {
+		t.Fatalf("Start: %v", err)
+	}
+	if _, err := r.Stop(); err != nil {
+		t.Fatalf("Stop: %v", err)
+	}
+	// arecord's -d bounds a runaway recording even if Stop is never called.
+	assertArgs(t, cap.spec.args, "-d", "90")
+}
+
+func TestRecordedTempFileDeletedAfterStop(t *testing.T) {
+	dir := t.TempDir()
+	cap := &captured{}
+	r := NewRecorder(RecorderOptions{
+		Platform: PlatformLinux,
+		starter:  fileWritingStarter(t, cap, wavFixture()),
+		tempDir:  func() (string, error) { return dir, nil },
+	})
+	if err := r.Start(); err != nil {
+		t.Fatalf("Start: %v", err)
+	}
+	if _, err := r.Stop(); err != nil {
+		t.Fatalf("Stop: %v", err)
+	}
+	entries, _ := os.ReadDir(dir)
+	if len(entries) != 0 {
+		t.Errorf("recorded audio should be deleted after Stop; found %d files", len(entries))
+	}
+}
+
+func TestStreamingSilenceAutoStop(t *testing.T) {
+	// Speech (loud) then a run of silence longer than silenceHold must auto-stop.
+	rate := 16000
+	chunk := chunkSizeBytes(rate)
+	loud := make([]byte, chunk)
+	for i := 0; i+1 < len(loud); i += 2 {
+		loud[i], loud[i+1] = 0x00, 0x40 // +16384, well above threshold
+	}
+	silence := make([]byte, chunk) // zeros
+	var buf []byte
+	buf = append(buf, loud...)
+	silentChunks := int(silenceHold/chunkInterval) + 3
+	for i := 0; i < silentChunks; i++ {
+		buf = append(buf, silence...)
+	}
+	starter := func(commandSpec) (processHandle, io.ReadCloser, error) {
+		return newFakeProcess(), io.NopCloser(bytes.NewReader(buf)), nil
+	}
+	r := NewRecorder(RecorderOptions{
+		Platform:        PlatformLinux,
+		SampleRate:      rate,
+		SilenceAutoStop: true,
+		starter:         starter,
+		tempDir:         testTempDir(t),
+	})
+	chunks, stop, err := r.StartStreaming()
+	if err != nil {
+		t.Fatalf("StartStreaming: %v", err)
+	}
+	defer stop()
+	// Draining must terminate on its own once silence auto-stop fires.
+	drained := make(chan struct{})
+	go func() {
+		for range chunks {
+		}
+		close(drained)
+	}()
+	select {
+	case <-drained:
+	case <-time.After(3 * time.Second):
+		t.Fatal("silence auto-stop did not end the stream")
+	}
+}
+
+func TestChunkPeak(t *testing.T) {
+	loud := []byte{0x00, 0x40} // +16384
+	if got := chunkPeak(loud); got != 16384 {
+		t.Errorf("peak = %d, want 16384", got)
+	}
+	quiet := []byte{0x10, 0x00} // +16
+	if got := chunkPeak(quiet); got != 16 {
+		t.Errorf("peak = %d, want 16", got)
+	}
+	min := []byte{0x00, 0x80} // -32768 -> clamped to 32767
+	if got := chunkPeak(min); got != 32767 {
+		t.Errorf("peak = %d, want 32767 (clamp)", got)
+	}
+}
+
+func TestDetectWindowsAudioDevice(t *testing.T) {
+	listing := `[dshow @ 0000] DirectShow audio devices
+[dshow @ 0000]  "Microphone (USB Audio)" (audio)
+[dshow @ 0000]     Alternative name "@device_cm_..."`
+	runOutput := func(context.Context, string, ...string) ([]byte, error) { return []byte(listing), nil }
+	got, err := detectWindowsAudioDevice(runOutput)
+	if err != nil {
+		t.Fatalf("detect: %v", err)
+	}
+	if got != "Microphone (USB Audio)" {
+		t.Errorf("device = %q", got)
+	}
+}
+
+func TestSniffFormat(t *testing.T) {
+	if SniffFormat(wavFixture()) != FormatWAV {
+		t.Error("wav not detected")
+	}
+	if SniffFormat(m4aFixture()) != FormatM4A {
+		t.Error("m4a not detected")
+	}
+	if SniffFormat([]byte("nope")) != FormatUnknown {
+		t.Error("unknown not detected")
+	}
+}
+
+func m4aFixture() []byte {
+	b := make([]byte, 16)
+	copy(b[4:], []byte("ftyp"))
+	copy(b[8:], []byte("M4A "))
+	return b
+}
+
+func assertArgs(t *testing.T, args []string, want ...string) {
+	t.Helper()
+	if !containsSubseq(args, want) {
+		t.Errorf("argv %v missing subsequence %v", args, want)
+	}
+}
+
+func containsSubseq(hay, needle []string) bool {
+	if len(needle) == 0 {
+		return true
+	}
+	for i := 0; i+len(needle) <= len(hay); i++ {
+		if equalSlice(hay[i:i+len(needle)], needle) {
+			return true
+		}
+	}
+	return false
+}
+
+func equalSlice(a, b []string) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	for i := range a {
+		if a[i] != b[i] {
+			return false
+		}
+	}
+	return true
+}
+
+func TestChunkLevel(t *testing.T) {
+	// Silence → ~0.
+	silence := make([]byte, 640)
+	if lvl := ChunkLevel(silence); lvl > 0.01 {
+		t.Errorf("silence level = %f, want ~0", lvl)
+	}
+	// A loud full-scale tone → clamped to 1.
+	loud := make([]byte, 640)
+	for i := 0; i+1 < len(loud); i += 2 {
+		loud[i], loud[i+1] = 0xFF, 0x7F // +32767
+	}
+	if lvl := ChunkLevel(loud); lvl < 0.99 {
+		t.Errorf("full-scale level = %f, want ~1", lvl)
+	}
+	// A normal speech-level signal (~-30 dBFS) should land mid-meter, not pinned
+	// to the bottom (the whole point of the dB mapping).
+	mid := make([]byte, 640)
+	for i := 0; i+1 < len(mid); i += 2 {
+		mid[i], mid[i+1] = byte(1000&0xFF), byte(1000>>8) // ≈ -30 dBFS
+	}
+	if lvl := ChunkLevel(mid); lvl < 0.4 || lvl > 0.75 {
+		t.Errorf("normal-speech level = %f, want a visible mid-range value", lvl)
+	}
+	// A quiet signal (~-45 dBFS) should be low but non-zero.
+	quiet := make([]byte, 640)
+	for i := 0; i+1 < len(quiet); i += 2 {
+		quiet[i], quiet[i+1] = byte(180&0xFF), byte(180>>8)
+	}
+	if lvl := ChunkLevel(quiet); lvl <= 0 || lvl > 0.35 {
+		t.Errorf("quiet level = %f, want a small non-zero value", lvl)
+	}
+}

internal/dictation/runner.go

@@ -0,0 +1,128 @@
+package dictation
+
+import (
+	"bytes"
+	"context"
+	"io"
+	"os"
+	"os/exec"
+	"time"
+)
+
+// commandSpec describes one capture-process invocation. Argv is always
+// discrete — never a shell string (the same invariant documented in
+// internal/imageinput/clipboard.go).
+type commandSpec struct {
+	name string
+	args []string
+	// wantStdout wires up a stdout pipe (streaming capture reads raw PCM).
+	wantStdout bool
+	// stopViaStdin, when non-empty, makes graceful stop write this to the
+	// process's stdin instead of signaling — ffmpeg finalizes cleanly on "q",
+	// and Windows has no os.Interrupt delivery anyway.
+	stopViaStdin string
+}
+
+// processHandle is a started capture process. Injectable via processStarter so
+// unit tests fake OS-boundary behavior, mirroring internal/lsp's serverStarter
+// seam (this package's clipboard.go-style shell-outs get the test seam that
+// file lacks).
+type processHandle interface {
+	// StopGracefully asks the tool to finish and flush output (SIGINT, or the
+	// spec's stdin stop text). The recorder falls back to Kill on timeout.
+	StopGracefully() error
+	Wait() error
+	Kill() error
+}
+
+// processStarter launches a capture process, returning its handle and — when
+// the spec asks for it — its stdout pipe.
+type processStarter func(spec commandSpec) (processHandle, io.ReadCloser, error)
+
+// commandOutputRunner runs a short one-shot command to completion and returns
+// its combined output. Used for helper invocations that aren't recordings
+// (Termux start/stop, Windows ffmpeg device listing) and the offline
+// transcription exec — ctx lets a caller cancel/timeout a wedged process.
+type commandOutputRunner func(ctx context.Context, name string, args ...string) ([]byte, error)
+
+func startProcess(spec commandSpec) (processHandle, io.ReadCloser, error) {
+	cmd := exec.Command(spec.name, spec.args...)
+	var stdout io.ReadCloser
+	if spec.wantStdout {
+		pipe, err := cmd.StdoutPipe()
+		if err != nil {
+			return nil, nil, err
+		}
+		stdout = pipe
+	}
+	var stdin io.WriteCloser
+	if spec.stopViaStdin != "" {
+		pipe, err := cmd.StdinPipe()
+		if err != nil {
+			return nil, nil, err
+		}
+		stdin = pipe
+	}
+	if err := cmd.Start(); err != nil {
+		// StdoutPipe/StdinPipe allocate fds the runtime only reclaims via
+		// Wait; on Start failure the process is never established, so close
+		// any pipes we already opened to avoid leaking them.
+		if stdout != nil {
+			_ = stdout.Close()
+		}
+		if stdin != nil {
+			_ = stdin.Close()
+		}
+		return nil, nil, err
+	}
+	return &realProcess{cmd: cmd, stdin: stdin, stopText: spec.stopViaStdin}, stdout, nil
+}
+
+type realProcess struct {
+	cmd      *exec.Cmd
+	stdin    io.WriteCloser
+	stopText string
+}
+
+func (p *realProcess) StopGracefully() error {
+	if p.stopText != "" && p.stdin != nil {
+		_, err := io.WriteString(p.stdin, p.stopText)
+		closeErr := p.stdin.Close()
+		if err != nil {
+			return err
+		}
+		return closeErr
+	}
+	// os.Interrupt is how arecord/sox finalize their WAV header. Unsupported
+	// on Windows, but the only Windows tool (ffmpeg) stops via stdin above.
+	return p.cmd.Process.Signal(os.Interrupt)
+}
+
+func (p *realProcess) Wait() error { return p.cmd.Wait() }
+
+func (p *realProcess) Kill() error { return p.cmd.Process.Kill() }
+
+func runCommandOutput(ctx context.Context, name string, args ...string) ([]byte, error) {
+	cmd := exec.CommandContext(ctx, name, args...)
+	var out bytes.Buffer
+	cmd.Stdout = &out
+	cmd.Stderr = &out
+	err := cmd.Run()
+	return out.Bytes(), err
+}
+
+// waitWithTimeout waits for the process, killing it if it ignores the graceful
+// stop for longer than the grace window. Capture tools exit on SIGINT/"q"
+// almost instantly; a hang here means a wedged device driver, and a leaked
+// recording process holds the microphone open.
+func waitWithTimeout(proc processHandle, grace time.Duration) error {
+	done := make(chan error, 1)
+	go func() { done <- proc.Wait() }()
+	select {
+	case err := <-done:
+		return err
+	case <-time.After(grace):
+		_ = proc.Kill()
+		return <-done
+	}
+}

internal/dictation/server.go

@@ -0,0 +1,255 @@
+package dictation
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net"
+	"os"
+	"os/exec"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+)
+
+// DefaultServerPort is the localhost port the sherpa-onnx streaming server binds.
+const DefaultServerPort = 6006
+
+// ServerConfig configures the warm sherpa-onnx streaming server (§6a).
+type ServerConfig struct {
+	// Binary is the streaming server executable (default
+	// "sherpa-onnx-online-websocket-server"); looked up on PATH.
+	Binary string
+	// ModelPath is the sherpa-onnx streaming model directory (transducer:
+	// encoder/decoder/joiner + tokens).
+	ModelPath  string
+	Port       int
+	NumThreads int
+
+	// Test seams.
+	starter     processStarter
+	healthCheck func(ctx context.Context, port int) error
+	aliveCheck  func(port int) bool
+	now         func() time.Time
+}
+
+// ServerManager owns one long-lived sherpa-onnx streaming server, spawned lazily
+// on first streaming use and kept warm for the session — a websocket server with
+// ~1-2s startup latency can't be respawned per utterance (§6a). Its lifecycle
+// mirrors internal/lsp's Manager: lazy start, health-checked reuse, one restart
+// on a crashed process, torn down on exit. Safe for concurrent use.
+type ServerManager struct {
+	cfg ServerConfig
+
+	mu   sync.Mutex
+	proc processHandle
+	url  string
+}
+
+// NewServerManager builds a manager. Construction is side-effect free; the
+// server is only spawned on the first EnsureRunning.
+func NewServerManager(cfg ServerConfig) *ServerManager {
+	if cfg.Binary == "" {
+		cfg.Binary = "sherpa-onnx-online-websocket-server"
+	}
+	if cfg.Port == 0 {
+		cfg.Port = DefaultServerPort
+	}
+	if cfg.starter == nil {
+		cfg.starter = startProcess
+	}
+	if cfg.healthCheck == nil {
+		cfg.healthCheck = dialHealthCheck
+	}
+	if cfg.aliveCheck == nil {
+		cfg.aliveCheck = func(port int) bool { return portListening(port) }
+	}
+	if cfg.now == nil {
+		cfg.now = time.Now
+	}
+	return &ServerManager{cfg: cfg}
+}
+
+// EnsureRunning returns the websocket URL of a live server, starting one if
+// needed. A previously-started server whose process has since died is reaped and
+// replaced (mirroring the LSP manager's crashed-session eviction).
+func (m *ServerManager) EnsureRunning(ctx context.Context) (string, error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	if m.proc != nil {
+		if m.processAlive() {
+			return m.url, nil
+		}
+		// The cached server died; reap it so a fresh one starts below.
+		_ = m.proc.Kill()
+		m.proc = nil
+		m.url = ""
+	}
+
+	spec, err := onlineServerCommand(m.cfg)
+	if err != nil {
+		return "", err
+	}
+	proc, _, err := m.cfg.starter(spec)
+	if err != nil {
+		if errors.Is(err, exec.ErrNotFound) {
+			return "", &SetupError{
+				Tool: m.cfg.Binary,
+				Hint: "install sherpa-onnx and put its online-websocket-server binary on PATH (see docs/dictation.md)",
+			}
+		}
+		return "", fmt.Errorf("starting sherpa-onnx server: %w", err)
+	}
+
+	// Health-check the port before handing back a URL — the server takes ~1-2s to
+	// bind, and a client connecting too early would fail (§6a).
+	if err := m.cfg.healthCheck(ctx, m.cfg.Port); err != nil {
+		_ = proc.Kill()
+		return "", fmt.Errorf("sherpa-onnx server did not become ready: %w", err)
+	}
+	m.proc = proc
+	m.url = fmt.Sprintf("ws://127.0.0.1:%d", m.cfg.Port)
+	return m.url, nil
+}
+
+// processAlive reports whether the tracked server is still reachable. Probing
+// the port (rather than the process handle) reflects real reachability and is
+// the seam tests replace.
+func (m *ServerManager) processAlive() bool {
+	return m.cfg.aliveCheck(m.cfg.Port)
+}
+
+// portListening reports whether something accepts TCP connections on the port.
+func portListening(port int) bool {
+	conn, err := net.DialTimeout("tcp", net.JoinHostPort("127.0.0.1", strconv.Itoa(port)), 200*time.Millisecond)
+	if err != nil {
+		return false
+	}
+	_ = conn.Close()
+	return true
+}
+
+// Shutdown stops the running server. Called alongside the LSP manager's shutdown
+// on exit — a leaked warm server holds a port and CPU.
+func (m *ServerManager) Shutdown(ctx context.Context) error {
+	m.mu.Lock()
+	proc := m.proc
+	m.proc = nil
+	m.url = ""
+	m.mu.Unlock()
+	if proc == nil {
+		return nil
+	}
+	if err := proc.StopGracefully(); err != nil {
+		_ = proc.Kill()
+	}
+	done := make(chan error, 1)
+	go func() { done <- waitWithTimeout(proc, stopGrace) }()
+	select {
+	case err := <-done:
+		return err
+	case <-ctx.Done():
+		_ = proc.Kill()
+		return ctx.Err()
+	}
+}
+
+// URL returns the current server URL without starting one ("" when not running).
+func (m *ServerManager) URL() string {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	return m.url
+}
+
+// SetModelPath updates the model directory the server launches with, for a
+// mid-session config change (e.g. an F9 auto-download). It takes effect the next
+// time the server (re)starts; a running server is left as-is.
+func (m *ServerManager) SetModelPath(path string) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	if path != "" {
+		m.cfg.ModelPath = path
+	}
+}
+
+// onlineServerCommand builds the streaming-server argv from the model directory.
+// The online server uses a streaming transducer (encoder/decoder/joiner) plus
+// tokens — the shape the sherpa-onnx docs' example uses (§6a).
+func onlineServerCommand(cfg ServerConfig) (commandSpec, error) {
+	if strings.TrimSpace(cfg.ModelPath) == "" {
+		return commandSpec{}, &SetupError{
+			Tool: "local STT streaming model",
+			Hint: "set stt.localModelPath to a sherpa-onnx streaming model directory (see docs/dictation.md)",
+		}
+	}
+	files, err := onnxFilesIn(cfg.ModelPath)
+	if err != nil {
+		return commandSpec{}, &SetupError{Tool: "local STT streaming model", Hint: err.Error()}
+	}
+	tokens := findTokensFile(files)
+	// A streaming model ships encoder/decoder/joiner, often BOTH an int8 and an
+	// fp32 copy of each. Pick a CONSISTENT set — all int8 or all fp32 — because
+	// mixing (int8 encoder + fp32 decoder) is invalid. Prefer int8 (smaller,
+	// faster) when a full int8 set is present.
+	set := consistentQuantizedSet(files, "encoder", "decoder", "joiner")
+	var encoder, decoder, joiner string
+	if set != nil {
+		encoder, decoder, joiner = set[0], set[1], set[2]
+	}
+	if tokens == "" || encoder == "" || decoder == "" || joiner == "" {
+		return commandSpec{}, &SetupError{
+			Tool: "local STT streaming model",
+			Hint: fmt.Sprintf("streaming needs a transducer model (encoder/decoder/joiner .onnx + tokens.txt) in %q; see docs/dictation.md", cfg.ModelPath),
+		}
+	}
+	args := []string{
+		"--port=" + strconv.Itoa(cfg.Port),
+		"--tokens=" + tokens,
+		"--encoder=" + encoder,
+		"--decoder=" + decoder,
+		"--joiner=" + joiner,
+		"--decoding-method=greedy_search",
+	}
+	if cfg.NumThreads > 0 {
+		args = append(args, "--num-threads="+strconv.Itoa(cfg.NumThreads))
+	}
+	return commandSpec{name: cfg.Binary, args: args}, nil
+}
+
+func onnxFilesIn(dir string) (map[string]string, error) {
+	entries, err := os.ReadDir(dir)
+	if err != nil {
+		return nil, fmt.Errorf("stt.localModelPath %q is not readable: %v", dir, err)
+	}
+	files := map[string]string{}
+	for _, e := range entries {
+		if e.IsDir() {
+			continue
+		}
+		files[strings.ToLower(e.Name())] = dir + string(os.PathSeparator) + e.Name()
+	}
+	return files, nil
+}
+
+// dialHealthCheck polls the server's TCP port until it accepts a connection or
+// the deadline passes.
+func dialHealthCheck(ctx context.Context, port int) error {
+	addr := net.JoinHostPort("127.0.0.1", strconv.Itoa(port))
+	deadline := time.Now().Add(5 * time.Second)
+	for {
+		if ctx.Err() != nil {
+			return ctx.Err()
+		}
+		conn, err := net.DialTimeout("tcp", addr, 500*time.Millisecond)
+		if err == nil {
+			_ = conn.Close()
+			return nil
+		}
+		if time.Now().After(deadline) {
+			return fmt.Errorf("port %d not listening after 5s", port)
+		}
+		time.Sleep(100 * time.Millisecond)
+	}
+}

internal/dictation/server_test.go

@@ -0,0 +1,189 @@
+package dictation
+
+import (
+	"context"
+	"encoding/binary"
+	"errors"
+	"io"
+	"math"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"sync"
+	"testing"
+)
+
+func streamingModelDir(t *testing.T) string {
+	t.Helper()
+	dir := t.TempDir()
+	for _, f := range []string{"encoder.onnx", "decoder.onnx", "joiner.onnx", "tokens.txt"} {
+		if err := os.WriteFile(filepath.Join(dir, f), []byte("x"), 0o600); err != nil {
+			t.Fatal(err)
+		}
+	}
+	return dir
+}
+
+func TestServerManagerLazyStartAndReuse(t *testing.T) {
+	var startCount int
+	var mu sync.Mutex
+	starter := func(spec commandSpec) (processHandle, io.ReadCloser, error) {
+		mu.Lock()
+		startCount++
+		mu.Unlock()
+		if spec.name != "sherpa-onnx-online-websocket-server" {
+			t.Errorf("binary = %q", spec.name)
+		}
+		return newFakeProcess(), nil, nil
+	}
+	alive := true
+	m := NewServerManager(ServerConfig{
+		ModelPath:   streamingModelDir(t),
+		Port:        6006,
+		starter:     starter,
+		healthCheck: func(context.Context, int) error { return nil },
+		aliveCheck:  func(int) bool { return alive },
+	})
+
+	url, err := m.EnsureRunning(context.Background())
+	if err != nil {
+		t.Fatalf("EnsureRunning: %v", err)
+	}
+	if url != "ws://127.0.0.1:6006" {
+		t.Errorf("url = %q", url)
+	}
+	// Second call reuses the warm server (alive) — no new start.
+	if _, err := m.EnsureRunning(context.Background()); err != nil {
+		t.Fatalf("EnsureRunning reuse: %v", err)
+	}
+	if startCount != 1 {
+		t.Errorf("expected 1 start (warm reuse), got %d", startCount)
+	}
+}
+
+func TestServerManagerRestartsCrashedServer(t *testing.T) {
+	var startCount int
+	starter := func(commandSpec) (processHandle, io.ReadCloser, error) {
+		startCount++
+		return newFakeProcess(), nil, nil
+	}
+	alive := true
+	m := NewServerManager(ServerConfig{
+		ModelPath:   streamingModelDir(t),
+		starter:     starter,
+		healthCheck: func(context.Context, int) error { return nil },
+		aliveCheck:  func(int) bool { return alive },
+	})
+	if _, err := m.EnsureRunning(context.Background()); err != nil {
+		t.Fatal(err)
+	}
+	alive = false // simulate a crashed server
+	if _, err := m.EnsureRunning(context.Background()); err != nil {
+		t.Fatal(err)
+	}
+	if startCount != 2 {
+		t.Errorf("expected a restart (2 starts), got %d", startCount)
+	}
+}
+
+func TestServerManagerMissingBinaryIsSetupError(t *testing.T) {
+	m := NewServerManager(ServerConfig{
+		ModelPath: streamingModelDir(t),
+		starter:   func(commandSpec) (processHandle, io.ReadCloser, error) { return nil, nil, exec.ErrNotFound },
+	})
+	_, err := m.EnsureRunning(context.Background())
+	var setupErr *SetupError
+	if !errors.As(err, &setupErr) {
+		t.Fatalf("want *SetupError, got %v", err)
+	}
+}
+
+func TestServerManagerMissingModelIsSetupError(t *testing.T) {
+	m := NewServerManager(ServerConfig{
+		ModelPath: t.TempDir(), // empty dir, no onnx/tokens
+		starter:   func(commandSpec) (processHandle, io.ReadCloser, error) { return newFakeProcess(), nil, nil },
+	})
+	_, err := m.EnsureRunning(context.Background())
+	var setupErr *SetupError
+	if !errors.As(err, &setupErr) {
+		t.Fatalf("want *SetupError for missing streaming model, got %v", err)
+	}
+}
+
+func TestServerManagerShutdown(t *testing.T) {
+	proc := newFakeProcess()
+	m := NewServerManager(ServerConfig{
+		ModelPath:   streamingModelDir(t),
+		starter:     func(commandSpec) (processHandle, io.ReadCloser, error) { return proc, nil, nil },
+		healthCheck: func(context.Context, int) error { return nil },
+		aliveCheck:  func(int) bool { return true },
+	})
+	if _, err := m.EnsureRunning(context.Background()); err != nil {
+		t.Fatal(err)
+	}
+	if err := m.Shutdown(context.Background()); err != nil {
+		t.Fatalf("Shutdown: %v", err)
+	}
+	if !proc.stopped && !proc.killed {
+		t.Error("Shutdown should stop the server process")
+	}
+	if m.URL() != "" {
+		t.Error("URL should be empty after shutdown")
+	}
+}
+
+func TestOnlineServerCommandBuildsTransducerArgs(t *testing.T) {
+	spec, err := onlineServerCommand(ServerConfig{Binary: "sherpa-onnx-online-websocket-server", ModelPath: streamingModelDir(t), Port: 6007})
+	if err != nil {
+		t.Fatal(err)
+	}
+	joined := ""
+	for _, a := range spec.args {
+		joined += a + " "
+	}
+	for _, want := range []string{"--port=6007", "--tokens=", "--encoder=", "--decoder=", "--joiner=", "--decoding-method=greedy_search"} {
+		if !contains(joined, want) {
+			t.Errorf("missing %q in args: %s", want, joined)
+		}
+	}
+}
+
+func TestPCM16ToFloat32LE(t *testing.T) {
+	// int16 max (32767) and min (-32768), little-endian.
+	pcm := []byte{0xFF, 0x7F, 0x00, 0x80}
+	out := pcm16ToFloat32LE(pcm)
+	if len(out) != 8 {
+		t.Fatalf("expected 8 bytes (2 float32), got %d", len(out))
+	}
+	f0 := math.Float32frombits(binary.LittleEndian.Uint32(out[0:4]))
+	f1 := math.Float32frombits(binary.LittleEndian.Uint32(out[4:8]))
+	if f0 < 0.99 || f0 > 1.0 {
+		t.Errorf("32767 → %f, want ~1.0", f0)
+	}
+	if f1 != -1.0 {
+		t.Errorf("-32768 → %f, want -1.0", f1)
+	}
+}
+
+func TestParseSherpaStreamResult(t *testing.T) {
+	text, segment, final, ok := parseSherpaStreamResult([]byte(`{"text":" hello world ","segment":2,"is_final":true}`))
+	if !ok || text != "hello world" || segment != 2 || !final {
+		t.Errorf("parsed = (%q, %d, %v, %v)", text, segment, final, ok)
+	}
+	if _, _, _, ok := parseSherpaStreamResult([]byte("not json")); ok {
+		t.Error("non-JSON should not parse")
+	}
+}
+
+func contains(hay, needle string) bool {
+	return len(needle) == 0 || (len(hay) >= len(needle) && indexOf(hay, needle) >= 0)
+}
+
+func indexOf(hay, needle string) int {
+	for i := 0; i+len(needle) <= len(hay); i++ {
+		if hay[i:i+len(needle)] == needle {
+			return i
+		}
+	}
+	return -1
+}

internal/dictation/spill.go

@@ -0,0 +1,51 @@
+package dictation
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+// Recorded audio is staged in a hardened per-user temp directory, mirroring
+// internal/tools/spill.go (PR #506): uid-suffixed name so users on a shared
+// /tmp cannot collide, 0700 perms, and a pre-existing path is only accepted
+// when it is a real directory (not a symlink that would redirect recordings)
+// owned by the current user. Files are removed as soon as their bytes are
+// read back after Stop — audio never lingers on disk.
+
+func audioSpillRoot() string {
+	name := "zero-dictation"
+	if uid := os.Getuid(); uid >= 0 {
+		name = fmt.Sprintf("zero-dictation-%d", uid)
+	}
+	return filepath.Join(os.TempDir(), name)
+}
+
+func audioSpillDir() (string, error) {
+	dir := audioSpillRoot()
+	if err := os.MkdirAll(dir, 0o700); err != nil {
+		return "", err
+	}
+	// MkdirAll follows symlinks and leaves an existing directory untouched, so
+	// verify what is actually at the path.
+	info, err := os.Lstat(dir)
+	if err != nil {
+		return "", err
+	}
+	if !info.IsDir() {
+		return "", fmt.Errorf("dictation temp path %s is not a directory", dir)
+	}
+	// MkdirAll only applies 0o700 to dirs it creates; an existing directory
+	// (e.g. one created under a loose umask in a prior run) can be group- or
+	// world-readable. Tighten it so staged audio (PII) is never visible to
+	// other users on a shared /tmp.
+	if info.Mode().Perm() != 0o700 {
+		if err := os.Chmod(dir, 0o700); err != nil {
+			return "", fmt.Errorf("tightening dictation temp dir permissions: %w", err)
+		}
+	}
+	if err := checkAudioDirOwner(info); err != nil {
+		return "", err
+	}
+	return dir, nil
+}

internal/dictation/stream_smoke_test.go

@@ -0,0 +1,67 @@
+package dictation
+
+import (
+	"context"
+	"os"
+	"testing"
+	"time"
+)
+
+// TestLocalStreamingRealServer drives the full local streaming path against a
+// REAL sherpa-onnx-online-websocket-server + streaming model: spawn the server,
+// connect, feed a wav's PCM in 50ms chunks, and check the transcript. Opt-in:
+//
+//	ZERO_STT_STREAM_SERVER=/path/to/sherpa-onnx-online-websocket-server \
+//	ZERO_STT_STREAM_MODEL=/path/to/streaming-model-dir \
+//	ZERO_STT_STREAM_WAV=/path/to/16k-mono.wav \
+//	go test ./internal/dictation/ -run RealServer -v -timeout 5m
+func TestLocalStreamingRealServer(t *testing.T) {
+	server := os.Getenv("ZERO_STT_STREAM_SERVER")
+	model := os.Getenv("ZERO_STT_STREAM_MODEL")
+	wav := os.Getenv("ZERO_STT_STREAM_WAV")
+	if server == "" || model == "" || wav == "" {
+		t.Skip("set ZERO_STT_STREAM_SERVER, ZERO_STT_STREAM_MODEL, ZERO_STT_STREAM_WAV to run the streaming smoke test")
+	}
+	raw, err := os.ReadFile(wav)
+	if err != nil {
+		t.Fatal(err)
+	}
+	pcm := stripWavHeader(raw)
+
+	mgr := NewServerManager(ServerConfig{Binary: server, ModelPath: model, Port: 6100})
+	defer mgr.Shutdown(context.Background())
+	tr := NewLocalStreamingTranscriber(mgr)
+
+	chunks := make(chan []byte)
+	go func() {
+		defer close(chunks)
+		size := chunkSizeBytes(DefaultSampleRate) // 50ms
+		for off := 0; off < len(pcm); off += size {
+			end := off + size
+			if end > len(pcm) {
+				end = len(pcm)
+			}
+			chunks <- pcm[off:end]
+			time.Sleep(10 * time.Millisecond) // pace it a little, like a mic
+		}
+	}()
+
+	var partials int
+	final, err := tr.StreamTranscribe(context.Background(), chunks, func(string, bool) { partials++ })
+	if err != nil {
+		t.Fatalf("StreamTranscribe: %v", err)
+	}
+	if final == "" {
+		t.Fatal("streaming returned empty transcript")
+	}
+	t.Logf("streaming transcript (%d partials): %q", partials, final)
+}
+
+// stripWavHeader drops a standard 44-byte PCM WAV header, returning the raw
+// int16 samples. Good enough for the canonical 16kHz/mono/16-bit test wavs.
+func stripWavHeader(b []byte) []byte {
+	if len(b) > 44 && string(b[:4]) == "RIFF" {
+		return b[44:]
+	}
+	return b
+}

internal/dictation/transcriber.go

@@ -0,0 +1,45 @@
+package dictation
+
+import "context"
+
+// Transcriber turns captured audio into text. Batch (Transcribe) and streaming
+// (StreamTranscribe) are one interface but two independent code paths — a
+// batch-only provider (Groq/OpenAI, sherpa-onnx-offline) leaves
+// StreamTranscribe returning ErrStreamingUnsupported, and a streaming provider
+// still implements Transcribe for the batch/Termux fallback.
+type Transcriber interface {
+	// Transcribe returns the final text for one recorded clip.
+	Transcribe(ctx context.Context, audio []byte) (string, error)
+
+	// StreamTranscribe consumes PCM16 chunks and reports incremental results
+	// via onPartial(text, final) as decoding proceeds, returning the complete
+	// final transcript when the chunk channel closes.
+	//
+	// onPartial's text is the CURRENT best transcript of the utterance so far
+	// (cumulative, not a delta) so the composer can replace the live region
+	// wholesale; final marks a segment the provider considers settled.
+	//
+	// On a mid-stream failure (network drop for cloud, subprocess crash for
+	// local) StreamTranscribe returns the best-effort text accumulated from
+	// onPartial calls made so far PLUS a non-nil error — already-streamed text
+	// is never discarded, only the untranscribed tail after the failure is lost.
+	StreamTranscribe(ctx context.Context, chunks <-chan []byte, onPartial func(text string, final bool)) (string, error)
+}
+
+// SampleRate lets a Transcriber declare the capture rate its wire format
+// expects, so the recorder can be built to match (OpenAI Realtime wants 24kHz;
+// everything else uses 16kHz). A Transcriber that does not implement this uses
+// DefaultSampleRate.
+type SampleRate interface {
+	SampleRate() int
+}
+
+// RequiredSampleRate returns the capture rate a Transcriber needs.
+func RequiredSampleRate(t Transcriber) int {
+	if sr, ok := t.(SampleRate); ok {
+		if rate := sr.SampleRate(); rate > 0 {
+			return rate
+		}
+	}
+	return DefaultSampleRate
+}

internal/dictation/transcriber_cloud.go

@@ -0,0 +1,144 @@
+package dictation
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"mime/multipart"
+	"net/http"
+	"strings"
+
+	"github.com/Gitlawb/zero/internal/providers/providerio"
+)
+
+// CloudConfig configures a batch cloud transcriber. Groq and OpenAI share the
+// OpenAI-compatible /audio/transcriptions multipart endpoint — the design's
+// "each owns its endpoint/model specifics while sharing the request shape"
+// (§6). Key and base URL are resolved by the caller (TUI layer) from
+// config/credstore, keeping this type decoupled and unit-testable.
+type CloudConfig struct {
+	Provider string // ProviderGroq or ProviderOpenAI, for error messages
+	BaseURL  string // e.g. https://api.groq.com/openai/v1
+	APIKey   string
+	Model    string // e.g. whisper-large-v3-turbo, whisper-1
+	// Language optionally constrains recognition (ISO-639-1). Empty = auto.
+	Language string
+
+	// HTTPClient is injectable for tests; nil uses providerio's shared,
+	// stall-hardened client.
+	HTTPClient *http.Client
+}
+
+type cloudTranscriber struct {
+	cfg CloudConfig
+}
+
+// NewCloudTranscriber builds a batch transcriber for Groq or OpenAI.
+func NewCloudTranscriber(cfg CloudConfig) (Transcriber, error) {
+	if strings.TrimSpace(cfg.APIKey) == "" {
+		return nil, &SetupError{
+			Tool: cfg.Provider + " API key",
+			Hint: fmt.Sprintf("set a %s API key (run `zero auth`) to use cloud dictation", cfg.Provider),
+		}
+	}
+	if cfg.Model == "" {
+		return nil, fmt.Errorf("dictation: no model configured for provider %q", cfg.Provider)
+	}
+	base, err := providerio.NormalizeBaseURL(cfg.BaseURL, cfg.BaseURL, cfg.Provider)
+	if err != nil {
+		return nil, err
+	}
+	cfg.BaseURL = base
+	return &cloudTranscriber{cfg: cfg}, nil
+}
+
+func (c *cloudTranscriber) Transcribe(ctx context.Context, audio []byte) (string, error) {
+	if len(audio) == 0 {
+		return "", errors.New("no audio to transcribe")
+	}
+	body, contentType, err := c.buildMultipart(audio)
+	if err != nil {
+		return "", err
+	}
+	endpoint := c.cfg.BaseURL + "/audio/transcriptions"
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, endpoint, bytes.NewReader(body))
+	if err != nil {
+		return "", err
+	}
+	req.Header.Set("Content-Type", contentType)
+	req.Header.Set("Authorization", "Bearer "+c.cfg.APIKey)
+
+	resp, err := providerio.HTTPClient(c.cfg.HTTPClient).Do(req)
+	if err != nil {
+		return "", fmt.Errorf("%s transcription request failed: %w", c.cfg.Provider, err)
+	}
+	defer resp.Body.Close()
+	respBody, _ := io.ReadAll(io.LimitReader(resp.Body, 1<<20))
+	if resp.StatusCode != http.StatusOK {
+		msg := providerio.ClassifiedError(resp.StatusCode, strings.TrimSpace(string(respBody)), c.cfg.APIKey)
+		// A 401/403 is a fixable credential problem: surface it as a typed AuthError
+		// so the TUI can offer an inline key prompt instead of a dead-end message.
+		if resp.StatusCode == http.StatusUnauthorized || resp.StatusCode == http.StatusForbidden {
+			return "", &AuthError{Provider: c.cfg.Provider, Message: msg}
+		}
+		return "", errors.New(msg)
+	}
+	var parsed struct {
+		Text  string `json:"text"`
+		Error struct {
+			Message string `json:"message"`
+		} `json:"error"`
+	}
+	if err := json.Unmarshal(respBody, &parsed); err != nil {
+		return "", fmt.Errorf("%s transcription: could not parse response: %w", c.cfg.Provider, err)
+	}
+	if parsed.Error.Message != "" {
+		return "", fmt.Errorf("%s transcription error: %s", c.cfg.Provider, providerio.Redact(parsed.Error.Message, c.cfg.APIKey))
+	}
+	return strings.TrimSpace(parsed.Text), nil
+}
+
+// buildMultipart assembles the transcription upload. The file field name and
+// the "model"/"response_format" fields match the OpenAI audio API that Groq
+// mirrors. The filename's extension tells the server the container type —
+// SniffFormat keeps WAV/M4A honest so Termux's AAC uploads work.
+func (c *cloudTranscriber) buildMultipart(audio []byte) ([]byte, string, error) {
+	var buf bytes.Buffer
+	w := multipart.NewWriter(&buf)
+	fw, err := w.CreateFormFile("file", SniffFormat(audio).FileName())
+	if err != nil {
+		return nil, "", err
+	}
+	if _, err := fw.Write(audio); err != nil {
+		return nil, "", err
+	}
+	if err := w.WriteField("model", c.cfg.Model); err != nil {
+		return nil, "", err
+	}
+	if err := w.WriteField("response_format", "json"); err != nil {
+		return nil, "", err
+	}
+	if c.cfg.Language != "" {
+		if err := w.WriteField("language", c.cfg.Language); err != nil {
+			return nil, "", err
+		}
+	}
+	if err := w.Close(); err != nil {
+		return nil, "", err
+	}
+	return buf.Bytes(), w.FormDataContentType(), nil
+}
+
+// StreamTranscribe is not supported for the batch cloud providers (Groq has no
+// streaming product; OpenAI batch is one-shot). Streaming uses the dedicated
+// Deepgram/OpenAI-Realtime transcribers instead.
+func (c *cloudTranscriber) StreamTranscribe(context.Context, <-chan []byte, func(string, bool)) (string, error) {
+	return "", ErrStreamingUnsupported
+}
+
+// ErrStreamingUnsupported reports that a batch-only Transcriber cannot stream;
+// the caller falls back to the batch pipeline.
+var ErrStreamingUnsupported = errors.New("this transcription provider does not support streaming")

internal/dictation/transcriber_cloud_test.go

@@ -0,0 +1,142 @@
+package dictation
+
+import (
+	"context"
+	"errors"
+	"io"
+	"mime"
+	"mime/multipart"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+)
+
+func TestCloudTranscribeBuildsMultipartAndParsesText(t *testing.T) {
+	var gotModel, gotAuth, gotFilename string
+	var gotFileBytes []byte
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		gotAuth = r.Header.Get("Authorization")
+		if r.URL.Path != "/audio/transcriptions" {
+			t.Errorf("unexpected path %q", r.URL.Path)
+		}
+		mediaType, params, err := mime.ParseMediaType(r.Header.Get("Content-Type"))
+		if err != nil || !strings.HasPrefix(mediaType, "multipart/") {
+			t.Fatalf("bad content type %q: %v", r.Header.Get("Content-Type"), err)
+		}
+		mr := multipart.NewReader(r.Body, params["boundary"])
+		for {
+			part, err := mr.NextPart()
+			if err == io.EOF {
+				break
+			}
+			if err != nil {
+				t.Fatalf("multipart: %v", err)
+			}
+			switch part.FormName() {
+			case "model":
+				b, _ := io.ReadAll(part)
+				gotModel = string(b)
+			case "file":
+				gotFilename = part.FileName()
+				gotFileBytes, _ = io.ReadAll(part)
+			}
+		}
+		w.Header().Set("Content-Type", "application/json")
+		io.WriteString(w, `{"text":"  hello world  "}`)
+	}))
+	defer srv.Close()
+
+	tr, err := NewCloudTranscriber(CloudConfig{
+		Provider: ProviderGroq,
+		BaseURL:  srv.URL,
+		APIKey:   "secret-key",
+		Model:    "whisper-large-v3-turbo",
+	})
+	if err != nil {
+		t.Fatalf("NewCloudTranscriber: %v", err)
+	}
+	audio := wavFixture()
+	text, err := tr.Transcribe(context.Background(), audio)
+	if err != nil {
+		t.Fatalf("Transcribe: %v", err)
+	}
+	if text != "hello world" {
+		t.Errorf("text = %q, want trimmed 'hello world'", text)
+	}
+	if gotModel != "whisper-large-v3-turbo" {
+		t.Errorf("model field = %q", gotModel)
+	}
+	if gotAuth != "Bearer secret-key" {
+		t.Errorf("auth header = %q", gotAuth)
+	}
+	if gotFilename != "audio.wav" {
+		t.Errorf("filename = %q, want audio.wav", gotFilename)
+	}
+	if len(gotFileBytes) != len(audio) {
+		t.Errorf("uploaded %d file bytes, want %d", len(gotFileBytes), len(audio))
+	}
+}
+
+func TestCloudTranscribeM4AFilename(t *testing.T) {
+	var gotFilename string
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, params, _ := mime.ParseMediaType(r.Header.Get("Content-Type"))
+		mr := multipart.NewReader(r.Body, params["boundary"])
+		for {
+			part, err := mr.NextPart()
+			if err != nil {
+				break
+			}
+			if part.FormName() == "file" {
+				gotFilename = part.FileName()
+			}
+		}
+		io.WriteString(w, `{"text":"ok"}`)
+	}))
+	defer srv.Close()
+
+	tr, _ := NewCloudTranscriber(CloudConfig{Provider: ProviderOpenAI, BaseURL: srv.URL, APIKey: "k", Model: "whisper-1"})
+	if _, err := tr.Transcribe(context.Background(), m4aFixture()); err != nil {
+		t.Fatalf("Transcribe: %v", err)
+	}
+	if gotFilename != "audio.m4a" {
+		t.Errorf("filename = %q, want audio.m4a", gotFilename)
+	}
+}
+
+func TestCloudTranscribeAuthErrorClassified(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusUnauthorized)
+		io.WriteString(w, `{"error":{"message":"invalid api key sk-secret-key"}}`)
+	}))
+	defer srv.Close()
+
+	tr, _ := NewCloudTranscriber(CloudConfig{Provider: ProviderGroq, BaseURL: srv.URL, APIKey: "sk-secret-key", Model: "whisper-large-v3-turbo"})
+	_, err := tr.Transcribe(context.Background(), wavFixture())
+	if err == nil {
+		t.Fatal("expected error on 401")
+	}
+	if strings.Contains(err.Error(), "sk-secret-key") {
+		t.Errorf("API key leaked into error: %v", err)
+	}
+	if !strings.Contains(err.Error(), "auth error") {
+		t.Errorf("expected auth-error classification, got %v", err)
+	}
+}
+
+func TestNewCloudTranscriberRequiresKey(t *testing.T) {
+	_, err := NewCloudTranscriber(CloudConfig{Provider: ProviderGroq, BaseURL: "https://api.groq.com/openai/v1", Model: "m"})
+	var setupErr *SetupError
+	if !errors.As(err, &setupErr) {
+		t.Fatalf("want *SetupError for missing key, got %v", err)
+	}
+}
+
+func TestCloudTranscribeStreamingUnsupported(t *testing.T) {
+	tr, _ := NewCloudTranscriber(CloudConfig{Provider: ProviderGroq, BaseURL: "https://x", APIKey: "k", Model: "m"})
+	_, err := tr.StreamTranscribe(context.Background(), nil, nil)
+	if !errors.Is(err, ErrStreamingUnsupported) {
+		t.Errorf("want ErrStreamingUnsupported, got %v", err)
+	}
+}

internal/dictation/transcriber_deepgram.go

@@ -0,0 +1,163 @@
+package dictation
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+
+	"github.com/coder/websocket"
+)
+
+// DeepgramConfig configures the Deepgram streaming transcriber (§6b, default
+// cloud streaming provider). The key is resolved by the caller.
+type DeepgramConfig struct {
+	APIKey     string
+	Model      string // default "nova-3"
+	Language   string
+	SampleRate int // capture rate; default DefaultSampleRate (16kHz)
+	// BaseURL overrides the wss endpoint (tests point it at a fake server).
+	BaseURL string
+}
+
+type deepgramTranscriber struct {
+	cfg DeepgramConfig
+}
+
+// NewDeepgramTranscriber builds the Deepgram streaming transcriber.
+func NewDeepgramTranscriber(cfg DeepgramConfig) (Transcriber, error) {
+	if strings.TrimSpace(cfg.APIKey) == "" {
+		return nil, &SetupError{
+			Tool: "Deepgram API key",
+			Hint: "set a Deepgram API key (DEEPGRAM_API_KEY, or `zero auth`) to use Deepgram streaming dictation",
+		}
+	}
+	if cfg.Model == "" {
+		cfg.Model = "nova-3"
+	}
+	if cfg.SampleRate <= 0 {
+		cfg.SampleRate = DefaultSampleRate
+	}
+	if cfg.BaseURL == "" {
+		cfg.BaseURL = "wss://api.deepgram.com/v1/listen"
+	}
+	return &deepgramTranscriber{cfg: cfg}, nil
+}
+
+// Transcribe is unsupported — Deepgram is used only on the streaming path here.
+func (d *deepgramTranscriber) Transcribe(context.Context, []byte) (string, error) {
+	return "", ErrStreamingUnsupported
+}
+
+func (d *deepgramTranscriber) SampleRate() int { return d.cfg.SampleRate }
+
+func (d *deepgramTranscriber) StreamTranscribe(ctx context.Context, chunks <-chan []byte, onPartial func(string, bool)) (string, error) {
+	endpoint := d.buildURL()
+	conn, _, err := websocket.Dial(ctx, endpoint, &websocket.DialOptions{
+		HTTPHeader: http.Header{"Authorization": {"Token " + d.cfg.APIKey}},
+	})
+	if err != nil {
+		return "", fmt.Errorf("connecting to Deepgram: %w", err)
+	}
+	defer conn.CloseNow()
+
+	// Deepgram consumes raw linear16 (int16) PCM — the recorder's native format,
+	// so no conversion (unlike sherpa-onnx, which wants float32).
+	writeErrCh := make(chan error, 1)
+	go func() {
+		for chunk := range chunks {
+			if err := conn.Write(ctx, websocket.MessageBinary, chunk); err != nil {
+				writeErrCh <- err
+				return
+			}
+		}
+		// CloseStream flushes any buffered audio and returns final results before
+		// Deepgram closes the socket.
+		writeErrCh <- conn.Write(ctx, websocket.MessageText, []byte(`{"type":"CloseStream"}`))
+	}()
+
+	// Deepgram results are per-utterance segments, not cumulative: accumulate the
+	// is_final segments and append the current interim to build the full text.
+	var finals []string
+	var interim string
+	compose := func() string {
+		return strings.TrimSpace(strings.Join(append(finals, interim), " "))
+	}
+	for {
+		typ, data, err := conn.Read(ctx)
+		if err != nil {
+			// A clean close after CloseStream is success, not failure.
+			if websocket.CloseStatus(err) == websocket.StatusNormalClosure {
+				return compose(), nil
+			}
+			select {
+			case werr := <-writeErrCh:
+				if werr != nil {
+					err = werr
+				}
+			default:
+			}
+			return compose(), fmt.Errorf("Deepgram stream error: %w", err)
+		}
+		if typ != websocket.MessageText {
+			continue
+		}
+		transcript, isFinal, ok := parseDeepgramResult(data)
+		if !ok {
+			continue
+		}
+		if isFinal {
+			if transcript != "" {
+				finals = append(finals, transcript)
+			}
+			interim = ""
+		} else {
+			interim = transcript
+		}
+		if onPartial != nil {
+			onPartial(compose(), isFinal)
+		}
+	}
+}
+
+func (d *deepgramTranscriber) buildURL() string {
+	q := url.Values{}
+	q.Set("encoding", "linear16")
+	q.Set("sample_rate", strconv.Itoa(d.cfg.SampleRate))
+	q.Set("channels", "1")
+	q.Set("interim_results", "true")
+	q.Set("punctuate", "true")
+	q.Set("model", d.cfg.Model)
+	if d.cfg.Language != "" {
+		q.Set("language", d.cfg.Language)
+	}
+	return d.cfg.BaseURL + "?" + q.Encode()
+}
+
+// parseDeepgramResult extracts the transcript and is_final flag from a Deepgram
+// "Results" message: channel.alternatives[0].transcript.
+func parseDeepgramResult(data []byte) (transcript string, isFinal bool, ok bool) {
+	var msg struct {
+		Type    string `json:"type"`
+		IsFinal bool   `json:"is_final"`
+		Channel struct {
+			Alternatives []struct {
+				Transcript string `json:"transcript"`
+			} `json:"alternatives"`
+		} `json:"channel"`
+	}
+	if err := json.Unmarshal(data, &msg); err != nil {
+		return "", false, false
+	}
+	// Only "Results" messages carry transcripts; ignore Metadata/UtteranceEnd/etc.
+	if msg.Type != "" && msg.Type != "Results" {
+		return "", false, false
+	}
+	if len(msg.Channel.Alternatives) == 0 {
+		return "", false, false
+	}
+	return strings.TrimSpace(msg.Channel.Alternatives[0].Transcript), msg.IsFinal, true
+}

internal/dictation/transcriber_local.go

@@ -0,0 +1,391 @@
+package dictation
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strconv"
+	"strings"
+)
+
+// LocalConfig configures the offline sherpa-onnx batch transcriber. Every tier
+// (default/standard/high-end, §7) is just a different ModelPath — there are no
+// tier-specific code paths; the model family is detected from the files present.
+type LocalConfig struct {
+	// Binary is the sherpa-onnx-offline executable; looked up on PATH when a
+	// bare name. Empty defaults to "sherpa-onnx-offline".
+	Binary string
+	// ModelPath is the directory holding the model's .onnx + tokens.txt files
+	// (stt.localModelPath).
+	ModelPath  string
+	NumThreads int
+
+	// Test seams.
+	runOutput commandOutputRunner
+	tempDir   func() (string, error)
+}
+
+type localTranscriber struct {
+	cfg LocalConfig
+}
+
+// NewLocalTranscriber builds the offline transcriber. It does not touch the
+// filesystem or PATH until Transcribe runs, so a missing binary/model degrades
+// to a clear setup message at use time (matching internal/lsp).
+func NewLocalTranscriber(cfg LocalConfig) (Transcriber, error) {
+	if strings.TrimSpace(cfg.ModelPath) == "" {
+		return nil, &SetupError{
+			Tool: "local STT model",
+			Hint: "set stt.localModelPath to a sherpa-onnx model directory (see docs/dictation.md)",
+		}
+	}
+	if cfg.Binary == "" {
+		cfg.Binary = "sherpa-onnx-offline"
+	}
+	if cfg.runOutput == nil {
+		cfg.runOutput = runCommandOutput
+	}
+	if cfg.tempDir == nil {
+		cfg.tempDir = audioSpillDir
+	}
+	return &localTranscriber{cfg: cfg}, nil
+}
+
+func (l *localTranscriber) Transcribe(ctx context.Context, audio []byte) (string, error) {
+	if len(audio) == 0 {
+		return "", errors.New("no audio to transcribe")
+	}
+	modelArgs, err := detectModelArgs(l.cfg.ModelPath)
+	if err != nil {
+		return "", err
+	}
+
+	dir, err := l.cfg.tempDir()
+	if err != nil {
+		return "", fmt.Errorf("preparing dictation temp dir: %w", err)
+	}
+	ext := ".wav"
+	if SniffFormat(audio) == FormatM4A {
+		ext = ".m4a"
+	}
+	tmp, err := os.CreateTemp(dir, "stt-*"+ext)
+	if err != nil {
+		return "", fmt.Errorf("staging audio for transcription: %w", err)
+	}
+	path := tmp.Name()
+	defer os.Remove(path) // audio never lingers on disk (§12)
+	if _, err := tmp.Write(audio); err != nil {
+		tmp.Close()
+		return "", err
+	}
+	if err := tmp.Close(); err != nil {
+		return "", err
+	}
+
+	args := make([]string, 0, len(modelArgs)+3)
+	args = append(args, modelArgs...)
+	if l.cfg.NumThreads > 0 {
+		args = append(args, "--num-threads="+strconv.Itoa(l.cfg.NumThreads))
+	}
+	args = append(args, path)
+
+	// Fail fast if already cancelled; ctx also propagates into the exec below so a
+	// wedged sherpa-onnx-offline is killed on cancel/timeout rather than hanging.
+	if err := ctx.Err(); err != nil {
+		return "", err
+	}
+	out, err := l.cfg.runOutput(ctx, l.cfg.Binary, args...)
+	if err != nil {
+		if errors.Is(err, exec.ErrNotFound) {
+			return "", &SetupError{
+				Tool: l.cfg.Binary,
+				Hint: "install sherpa-onnx and put its offline binary on PATH (see docs/dictation.md)",
+			}
+		}
+		return "", fmt.Errorf("sherpa-onnx transcription failed: %w (%s)", err, lastLines(out, 3))
+	}
+	text := parseSherpaOutput(out)
+	if text == "" {
+		return "", fmt.Errorf("sherpa-onnx produced no transcript (output: %s)", lastLines(out, 3))
+	}
+	return text, nil
+}
+
+// detectModelArgs inspects a sherpa-onnx model directory and builds the
+// family-specific --*=path flags. Supports the families sherpa-onnx-offline
+// accepts; Moonshine (the design's default/standard/high-end tiers) is the
+// primary target. tokens.txt is required by every family.
+func detectModelArgs(dir string) ([]string, error) {
+	entries, err := os.ReadDir(dir)
+	if err != nil {
+		return nil, &SetupError{
+			Tool: "local STT model",
+			Hint: fmt.Sprintf("stt.localModelPath %q is not readable: %v", dir, err),
+		}
+	}
+	files := map[string]string{} // lowercased basename -> absolute path
+	for _, e := range entries {
+		if e.IsDir() {
+			continue
+		}
+		files[strings.ToLower(e.Name())] = filepath.Join(dir, e.Name())
+	}
+
+	tokens := findTokensFile(files)
+	if tokens == "" {
+		return nil, &SetupError{
+			Tool: "local STT model",
+			Hint: fmt.Sprintf("no tokens.txt found in stt.localModelPath %q — is it a sherpa-onnx model directory?", dir),
+		}
+	}
+
+	dirName := strings.ToLower(filepath.Base(dir))
+
+	// Order matters — check the most specific signatures first so a model is
+	// never mis-classified as a family it only partially resembles.
+
+	// Moonshine: preprocessor + encoder + cached/uncached decoders. Its files are
+	// "encode"/"decode" (no trailing "r"), so they never collide with the
+	// "encoder"/"decoder" families below.
+	if pre := findContains(files, "preprocess"); pre != "" {
+		enc := findContains(files, "encode")
+		// "uncached_decode" CONTAINS "cached_decode", so match the cached decoder
+		// as "cached" AND not "uncached" to disambiguate (map order is random).
+		unc := findOnnxMatching(files, "uncached", "")
+		cac := findOnnxMatching(files, "cached", "uncached")
+		if enc != "" && unc != "" && cac != "" {
+			return []string{
+				"--moonshine-preprocessor=" + pre,
+				"--moonshine-encoder=" + enc,
+				"--moonshine-uncached-decoder=" + unc,
+				"--moonshine-cached-decoder=" + cac,
+				"--tokens=" + tokens,
+			}, nil
+		}
+	}
+
+	// Transducer (Zipformer/Conformer): encoder + decoder + joiner, matched as a
+	// consistent int8-or-fp32 set (mixing quantizations is invalid).
+	if set := consistentQuantizedSet(files, "encoder", "decoder", "joiner"); set != nil {
+		return []string{"--encoder=" + set[0], "--decoder=" + set[1], "--joiner=" + set[2], "--tokens=" + tokens}, nil
+	}
+
+	// Encoder+decoder families that share Whisper's file shape (encoder + decoder,
+	// no joiner) but need their own flags — FireRedASR-AED, Canary, Cohere. They are
+	// indistinguishable from Whisper by files alone, so disambiguate by name FIRST;
+	// anything unnamed falls through to the Whisper default below.
+	for _, fam := range encoderDecoderFamilies {
+		if nameMatchesFamily(dirName, files, fam.match) {
+			if set := consistentQuantizedSet(files, "encoder", "decoder"); set != nil {
+				return []string{fam.encoderFlag + "=" + set[0], fam.decoderFlag + "=" + set[1], "--tokens=" + tokens}, nil
+			}
+		}
+	}
+
+	// Whisper: encoder + decoder, NO joiner. Sherpa's Whisper files are named
+	// "<model>-encoder.onnx" / "<model>-decoder.onnx" (NOT "whisper-encoder"), so
+	// match on the encoder/decoder roles — a consistent pair — after transducer
+	// (which owns the encoder/decoder/joiner shape) has already been ruled out.
+	if set := consistentQuantizedSet(files, "encoder", "decoder"); set != nil {
+		return []string{"--whisper-encoder=" + set[0], "--whisper-decoder=" + set[1], "--tokens=" + tokens}, nil
+	}
+
+	// Single-model families: one generic model .onnx + tokens, indistinguishable by
+	// file shape, so they are told apart by the model directory/file name. This
+	// covers SenseVoice, Paraformer, and the CTC families (FireRedASR-CTC, NeMo,
+	// TeleSpeech, WeNet, Zipformer-CTC, Dolphin, Omnilingual). Ordered most-specific
+	// first so a compound name (e.g. "fire-red-asr2-ctc") matches its own family
+	// before a generic token in it (e.g. bare "ctc") could steer it elsewhere.
+	if m := singleModelOnnx(files); m != "" {
+		for _, fam := range singleModelFamilies {
+			if nameMatchesFamily(dirName, files, fam.match) {
+				return []string{fam.flag + "=" + m, "--tokens=" + tokens}, nil
+			}
+		}
+	}
+
+	return nil, &SetupError{
+		Tool: "local STT model",
+		Hint: fmt.Sprintf("could not recognize the model family in %q (supported: Moonshine, Whisper, transducer/Zipformer, Paraformer, SenseVoice, and the CTC families FireRedASR/NeMo/TeleSpeech/WeNet/Zipformer-CTC/Dolphin/Omnilingual). See docs/dictation.md", dir),
+	}
+}
+
+// singleModelFamilies maps a model's directory/file-name signature to the
+// sherpa-onnx-offline flag for that single-file family. Each family ships exactly
+// one generic model .onnx (+ tokens), so only the name tells them apart. Ordered
+// so a specific compound name wins before a broader one.
+var singleModelFamilies = []struct {
+	match []string // name substrings (any hit); most-specific spellings first
+	flag  string
+}{
+	{[]string{"fire-red-asr2-ctc", "fire-red-asr-ctc", "fire-red-asr", "firered"}, "--fire-red-asr-ctc"},
+	{[]string{"nemo-ctc", "nemo_ctc"}, "--nemo-ctc-model"},
+	{[]string{"zipformer2-ctc", "zipformer-ctc"}, "--zipformer-ctc-model"},
+	{[]string{"telespeech"}, "--telespeech-ctc"},
+	{[]string{"wenet"}, "--wenet-ctc-model"},
+	{[]string{"dolphin"}, "--dolphin-model"},
+	{[]string{"omnilingual"}, "--omnilingual-asr-model"},
+	{[]string{"medasr"}, "--medasr"},
+	{[]string{"tdnn"}, "--tdnn-model"},
+	{[]string{"sense-voice", "sensevoice"}, "--sense-voice-model"},
+	{[]string{"paraformer"}, "--paraformer"},
+}
+
+// encoderDecoderFamilies are offline families shaped like Whisper (an encoder +
+// decoder .onnx, no joiner) but needing their own flags; matched by name before
+// the Whisper fallback claims the shape.
+var encoderDecoderFamilies = []struct {
+	match       []string
+	encoderFlag string
+	decoderFlag string
+}{
+	{[]string{"fire-red-asr"}, "--fire-red-asr-encoder", "--fire-red-asr-decoder"},
+	{[]string{"canary"}, "--canary-encoder", "--canary-decoder"},
+	{[]string{"cohere"}, "--cohere-transcribe-encoder", "--cohere-transcribe-decoder"},
+}
+
+// nameMatchesFamily reports whether the model directory name or any of its .onnx
+// filenames contain one of the family's signature substrings.
+func nameMatchesFamily(dirName string, files map[string]string, subs []string) bool {
+	for _, sub := range subs {
+		if strings.Contains(dirName, sub) {
+			return true
+		}
+		for name := range files {
+			if strings.HasSuffix(name, ".onnx") && strings.Contains(name, sub) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// consistentQuantizedSet returns one file per role (in order), preferring an
+// int8 build of each but falling back to fp32 when a role has no int8 file.
+// Returns nil when any role is entirely missing.
+//
+// Models legitimately SHIP mixed quantization — e.g. the x-asr streaming
+// zipformers ship an int8 encoder and joiner with an fp32 decoder — and
+// sherpa-onnx accepts that. So this must NOT require every role to share one
+// quantization; it just needs one file per role, favoring the smaller int8 when
+// a choice exists. (When a model ships both int8 and fp32 for every role, this
+// still picks all-int8, since int8 is available for each.)
+func consistentQuantizedSet(files map[string]string, roles ...string) []string {
+	pick := func(role string, int8Only bool) string {
+		for name, path := range files {
+			if !strings.HasSuffix(name, ".onnx") || !strings.Contains(name, role) {
+				continue
+			}
+			if int8Only && !strings.Contains(name, "int8") {
+				continue
+			}
+			return path
+		}
+		return ""
+	}
+	out := make([]string, len(roles))
+	for i, role := range roles {
+		p := pick(role, true) // prefer int8 (smaller, faster)
+		if p == "" {
+			p = pick(role, false) // fall back to fp32 for this role
+		}
+		if p == "" {
+			return nil // this role is genuinely absent
+		}
+		out[i] = p
+	}
+	return out
+}
+
+// findTokensFile returns the model's tokens file. It is usually "tokens.txt",
+// but some families (e.g. Whisper) prefix it as "<model>-tokens.txt".
+func findTokensFile(files map[string]string) string {
+	if p := files["tokens.txt"]; p != "" {
+		return p
+	}
+	for name, path := range files {
+		if strings.HasSuffix(name, "tokens.txt") {
+			return path
+		}
+	}
+	return ""
+}
+
+// singleModelOnnx returns the model's single .onnx file (preferring an int8
+// build), for families like SenseVoice/Paraformer that ship exactly one.
+func singleModelOnnx(files map[string]string) string {
+	best := ""
+	for name, path := range files {
+		if !strings.HasSuffix(name, ".onnx") {
+			continue
+		}
+		if strings.Contains(name, "int8") {
+			return path
+		}
+		best = path
+	}
+	return best
+}
+
+// findOnnxMatching returns an .onnx file whose name contains `must` and, when
+// `exclude` is non-empty, does NOT contain `exclude` — used to tell the cached
+// from the uncached Moonshine decoder.
+func findOnnxMatching(files map[string]string, must, exclude string) string {
+	for name, path := range files {
+		if !strings.HasSuffix(name, ".onnx") || !strings.Contains(name, must) {
+			continue
+		}
+		if exclude != "" && strings.Contains(name, exclude) {
+			continue
+		}
+		return path
+	}
+	return ""
+}
+
+func findContains(files map[string]string, substr string) string {
+	for name, path := range files {
+		if strings.HasSuffix(name, ".onnx") && strings.Contains(name, substr) {
+			return path
+		}
+	}
+	return ""
+}
+
+// parseSherpaOutput extracts the transcript from sherpa-onnx-offline's output.
+// The binary prints a JSON object with a "text" field (amid diagnostic lines);
+// scan for the first line that parses as such.
+func parseSherpaOutput(out []byte) string {
+	for _, line := range bytes.Split(out, []byte("\n")) {
+		trimmed := bytes.TrimSpace(line)
+		if len(trimmed) == 0 || trimmed[0] != '{' {
+			continue
+		}
+		var parsed struct {
+			Text string `json:"text"`
+		}
+		if err := json.Unmarshal(trimmed, &parsed); err == nil && strings.TrimSpace(parsed.Text) != "" {
+			return strings.TrimSpace(parsed.Text)
+		}
+	}
+	return ""
+}
+
+func lastLines(out []byte, n int) string {
+	lines := strings.Split(strings.TrimSpace(string(out)), "\n")
+	if len(lines) > n {
+		lines = lines[len(lines)-n:]
+	}
+	return strings.Join(lines, " | ")
+}
+
+// StreamTranscribe is unsupported for the offline binary; local streaming uses
+// the sherpa-onnx websocket server transcriber instead.
+func (l *localTranscriber) StreamTranscribe(context.Context, <-chan []byte, func(string, bool)) (string, error) {
+	return "", ErrStreamingUnsupported
+}

internal/dictation/transcriber_local_stream.go

@@ -0,0 +1,166 @@
+package dictation
+
+import (
+	"context"
+	"encoding/binary"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"math"
+	"strings"
+
+	"github.com/coder/websocket"
+)
+
+// localStreamingTranscriber streams audio to the warm sherpa-onnx websocket
+// server (§6a). The server keeps encoder state across chunks (a true streaming
+// transducer), so partials arrive as decoding proceeds — no redundant
+// re-inference.
+//
+// Wire protocol (verified against sherpa-onnx's reference client, NOT the
+// plan's "16-bit PCM" description, which was imprecise): the client sends
+// binary frames of little-endian float32 samples normalized to [-1, 1]
+// (int16/32768), then the text "Done" to end; the server replies with JSON
+// result messages and finally the text "Done!" to signal completion.
+type localStreamingTranscriber struct {
+	manager *ServerManager
+}
+
+// NewLocalStreamingTranscriber builds a streaming transcriber backed by the
+// shared, session-long sherpa-onnx server manager.
+func NewLocalStreamingTranscriber(manager *ServerManager) Transcriber {
+	return &localStreamingTranscriber{manager: manager}
+}
+
+// Transcribe is not this transcriber's job — the streaming path uses
+// StreamTranscribe; the batch/Termux fallback uses the offline transcriber.
+func (l *localStreamingTranscriber) Transcribe(context.Context, []byte) (string, error) {
+	return "", errors.New("local streaming transcriber does not support batch transcription")
+}
+
+func (l *localStreamingTranscriber) StreamTranscribe(ctx context.Context, chunks <-chan []byte, onPartial func(string, bool)) (string, error) {
+	url, err := l.manager.EnsureRunning(ctx)
+	if err != nil {
+		return "", err
+	}
+	conn, err := dialWithOneRestart(ctx, l.manager, url)
+	if err != nil {
+		return "", fmt.Errorf("connecting to sherpa-onnx server: %w", err)
+	}
+	defer conn.CloseNow()
+
+	// Writer goroutine: forward converted chunks, then signal end. A write error
+	// (server crashed) cancels the read side via writeErr.
+	writeErrCh := make(chan error, 1)
+	go func() {
+		for chunk := range chunks {
+			if err := conn.Write(ctx, websocket.MessageBinary, pcm16ToFloat32LE(chunk)); err != nil {
+				writeErrCh <- err
+				return
+			}
+		}
+		writeErrCh <- conn.Write(ctx, websocket.MessageText, []byte("Done"))
+	}()
+
+	// The server reports "text" PER SEGMENT, not cumulatively for the whole
+	// utterance: when it detects an endpoint (a pause between phrases, or the
+	// trailing silence when recording stops) it finalizes the current segment, bumps
+	// "segment", and resets "text" to "" for the next one. So we accumulate the text
+	// of every segment — otherwise a new segment's (often empty) result would
+	// overwrite everything already transcribed, and the transcript would vanish on
+	// stop. Displayed/returned text is all segments joined in order.
+	var segmentTexts []string
+	joinSegments := func() string {
+		parts := make([]string, 0, len(segmentTexts))
+		for _, s := range segmentTexts {
+			if t := strings.TrimSpace(s); t != "" {
+				parts = append(parts, t)
+			}
+		}
+		return strings.Join(parts, " ")
+	}
+	lastText := ""
+	for {
+		typ, data, err := conn.Read(ctx)
+		if err != nil {
+			// Mid-stream failure: return the best-effort text accumulated so far
+			// plus the error — already-streamed partials are never discarded (§6).
+			select {
+			case werr := <-writeErrCh:
+				if werr != nil {
+					err = werr
+				}
+			default:
+			}
+			return lastText, fmt.Errorf("sherpa-onnx stream error: %w", err)
+		}
+		if typ == websocket.MessageText && strings.TrimSpace(string(data)) == "Done!" {
+			break
+		}
+		text, segment, final, ok := parseSherpaStreamResult(data)
+		if !ok {
+			continue
+		}
+		if segment < 0 {
+			segment = 0
+		}
+		for len(segmentTexts) <= segment {
+			segmentTexts = append(segmentTexts, "")
+		}
+		segmentTexts[segment] = text
+		lastText = joinSegments()
+		if onPartial != nil {
+			onPartial(lastText, final)
+		}
+	}
+	_ = conn.Close(websocket.StatusNormalClosure, "")
+	return lastText, nil
+}
+
+// dialWithOneRestart dials the server, and on failure restarts it once and
+// retries — mirroring the LSP manager's single crashed-server recovery (§6/§6a).
+func dialWithOneRestart(ctx context.Context, manager *ServerManager, url string) (*websocket.Conn, error) {
+	conn, _, err := websocket.Dial(ctx, url, nil)
+	if err == nil {
+		return conn, nil
+	}
+	// The warm server may have died between EnsureRunning and Dial; reap and
+	// restart once.
+	_ = manager.Shutdown(ctx)
+	url, rerr := manager.EnsureRunning(ctx)
+	if rerr != nil {
+		return nil, rerr
+	}
+	conn, _, err = websocket.Dial(ctx, url, nil)
+	return conn, err
+}
+
+// parseSherpaStreamResult extracts one server JSON result. "text" is the
+// hypothesis for the CURRENT segment (segment index in "segment"), which resets
+// each time the recognizer endpoints — so the caller must accumulate per segment,
+// not treat "text" as the whole-utterance transcript. "is_final" marks a settled
+// segment.
+func parseSherpaStreamResult(data []byte) (text string, segment int, final bool, ok bool) {
+	var parsed struct {
+		Text    string `json:"text"`
+		Segment int    `json:"segment"`
+		IsFinal bool   `json:"is_final"`
+	}
+	if err := json.Unmarshal(data, &parsed); err != nil {
+		return "", 0, false, false
+	}
+	return strings.TrimSpace(parsed.Text), parsed.Segment, parsed.IsFinal, true
+}
+
+// pcm16ToFloat32LE converts a little-endian int16 PCM chunk to the little-endian
+// float32 samples (normalized to [-1, 1]) the sherpa-onnx server expects.
+func pcm16ToFloat32LE(pcm []byte) []byte {
+	n := len(pcm) / 2
+	out := make([]byte, n*4)
+	for i := 0; i < n; i++ {
+		s := int16(uint16(pcm[2*i]) | uint16(pcm[2*i+1])<<8)
+		bits := math.Float32bits(float32(s) / 32768.0)
+		binary.LittleEndian.PutUint32(out[4*i:], bits)
+	}
+	return out
+}

internal/dictation/transcriber_local_test.go

@@ -0,0 +1,269 @@
+package dictation
+
+import (
+	"context"
+	"errors"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func writeModelDir(t *testing.T, files ...string) string {
+	t.Helper()
+	dir := t.TempDir()
+	for _, f := range files {
+		if err := os.WriteFile(filepath.Join(dir, f), []byte("x"), 0o600); err != nil {
+			t.Fatal(err)
+		}
+	}
+	return dir
+}
+
+func TestLocalTranscribeMoonshineArgs(t *testing.T) {
+	dir := writeModelDir(t,
+		"preprocess.onnx", "encode.onnx", "uncached_decode.onnx", "cached_decode.onnx", "tokens.txt")
+	var gotBin string
+	var gotArgs []string
+	runOutput := func(_ context.Context, name string, args ...string) ([]byte, error) {
+		gotBin, gotArgs = name, args
+		return []byte("Started\nDone!\n\n/tmp/a.wav\n{\"text\":\" transcribed speech \"}\n----"), nil
+	}
+	tr, err := NewLocalTranscriber(LocalConfig{ModelPath: dir, runOutput: runOutput, tempDir: func() (string, error) { return t.TempDir(), nil }})
+	if err != nil {
+		t.Fatalf("NewLocalTranscriber: %v", err)
+	}
+	text, err := tr.Transcribe(context.Background(), wavFixture())
+	if err != nil {
+		t.Fatalf("Transcribe: %v", err)
+	}
+	if text != "transcribed speech" {
+		t.Errorf("text = %q", text)
+	}
+	if gotBin != "sherpa-onnx-offline" {
+		t.Errorf("binary = %q", gotBin)
+	}
+	joined := strings.Join(gotArgs, " ")
+	for _, want := range []string{"--moonshine-preprocessor=", "--moonshine-encoder=", "--moonshine-uncached-decoder=", "--moonshine-cached-decoder=", "--tokens="} {
+		if !strings.Contains(joined, want) {
+			t.Errorf("missing flag %q in %q", want, joined)
+		}
+	}
+}
+
+func TestLocalTranscribeTransducerArgs(t *testing.T) {
+	dir := writeModelDir(t, "encoder-epoch-99.onnx", "decoder-epoch-99.onnx", "joiner-epoch-99.onnx", "tokens.txt")
+	var gotArgs []string
+	runOutput := func(_ context.Context, name string, args ...string) ([]byte, error) {
+		gotArgs = args
+		return []byte(`{"text":"hi"}`), nil
+	}
+	tr, _ := NewLocalTranscriber(LocalConfig{ModelPath: dir, runOutput: runOutput, tempDir: func() (string, error) { return t.TempDir(), nil }})
+	if _, err := tr.Transcribe(context.Background(), wavFixture()); err != nil {
+		t.Fatalf("Transcribe: %v", err)
+	}
+	joined := strings.Join(gotArgs, " ")
+	for _, want := range []string{"--encoder=", "--decoder=", "--joiner=", "--tokens="} {
+		if !strings.Contains(joined, want) {
+			t.Errorf("missing flag %q in %q", want, joined)
+		}
+	}
+}
+
+func TestDetectWhisperArgs(t *testing.T) {
+	// Sherpa Whisper models are named "<model>-encoder.onnx" (NOT "whisper-encoder")
+	// and prefix the tokens file as "<model>-tokens.txt".
+	dir := writeModelDir(t, "tiny.en-encoder.onnx", "tiny.en-encoder.int8.onnx",
+		"tiny.en-decoder.onnx", "tiny.en-decoder.int8.onnx", "tiny.en-tokens.txt")
+	args, err := detectModelArgs(dir)
+	if err != nil {
+		t.Fatalf("Whisper detection failed: %v", err)
+	}
+	joined := strings.Join(args, " ")
+	if !strings.Contains(joined, "--whisper-encoder=") || !strings.Contains(joined, "--whisper-decoder=") {
+		t.Errorf("expected whisper flags, got %q", joined)
+	}
+	// Must not emit transducer flags (Whisper has no joiner).
+	if strings.Contains(joined, "--joiner=") || strings.Contains(joined, "--encoder=") {
+		t.Errorf("Whisper must not be detected as a transducer: %q", joined)
+	}
+	// Consistent quantization: both int8 (preferred) or both fp32, never mixed.
+	if strings.Contains(joined, "encoder.int8.onnx") != strings.Contains(joined, "decoder.int8.onnx") {
+		t.Errorf("mixed encoder/decoder quantization: %q", joined)
+	}
+}
+
+func TestDetectTransducerPrefersConsistentInt8(t *testing.T) {
+	dir := writeModelDir(t,
+		"encoder-epoch-99.onnx", "encoder-epoch-99.int8.onnx",
+		"decoder-epoch-99.onnx", "decoder-epoch-99.int8.onnx",
+		"joiner-epoch-99.onnx", "joiner-epoch-99.int8.onnx", "tokens.txt")
+	args, err := detectModelArgs(dir)
+	if err != nil {
+		t.Fatal(err)
+	}
+	joined := strings.Join(args, " ")
+	// All three int8 (preferred), consistently.
+	for _, want := range []string{"--encoder=", "encoder-epoch-99.int8.onnx", "joiner-epoch-99.int8.onnx"} {
+		if !strings.Contains(joined, want) {
+			t.Errorf("missing %q in %q", want, joined)
+		}
+	}
+}
+
+func TestDetectTransducerMixedQuantization(t *testing.T) {
+	// Some models ship an int8 encoder+joiner with an fp32 decoder (e.g. the
+	// x-asr streaming zipformers). Detection must accept that mix, not reject it.
+	dir := writeModelDir(t, "encoder.int8.onnx", "decoder.onnx", "joiner.int8.onnx", "tokens.txt")
+	args, err := detectModelArgs(dir)
+	if err != nil {
+		t.Fatalf("mixed-quantization transducer should be detected, got %v", err)
+	}
+	joined := strings.Join(args, " ")
+	if !strings.Contains(joined, "encoder.int8.onnx") || !strings.Contains(joined, "decoder.onnx") || !strings.Contains(joined, "joiner.int8.onnx") {
+		t.Errorf("expected the actual mixed files, got %q", joined)
+	}
+	// The fp32 decoder must not be mistaken for an int8 one.
+	if strings.Contains(joined, "decoder.int8") {
+		t.Errorf("no int8 decoder exists; should use decoder.onnx: %q", joined)
+	}
+}
+
+func TestDetectSenseVoiceByDirName(t *testing.T) {
+	dir := t.TempDir() // rename won't help; use a dir whose base contains sense-voice
+	sv := dir + "/sherpa-onnx-sense-voice-zh-en"
+	if err := os.MkdirAll(sv, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	for _, f := range []string{"model.int8.onnx", "tokens.txt"} {
+		os.WriteFile(sv+"/"+f, []byte("x"), 0o600)
+	}
+	args, err := detectModelArgs(sv)
+	if err != nil {
+		t.Fatalf("SenseVoice detection failed: %v", err)
+	}
+	if !strings.Contains(strings.Join(args, " "), "--sense-voice-model=") {
+		t.Errorf("expected sense-voice flag, got %v", args)
+	}
+}
+
+// writeNamedModelDir creates a model directory whose base name carries the family
+// signature (how sherpa-onnx distributes single-file / CTC models), with the given
+// files, and returns its path.
+func writeNamedModelDir(t *testing.T, base string, files ...string) string {
+	t.Helper()
+	dir := t.TempDir() + "/" + base
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	for _, f := range files {
+		if err := os.WriteFile(dir+"/"+f, []byte("x"), 0o600); err != nil {
+			t.Fatal(err)
+		}
+	}
+	return dir
+}
+
+func TestDetectSingleFileCTCFamilies(t *testing.T) {
+	// One generic model.onnx + tokens, family told apart by the directory name.
+	cases := []struct{ base, wantFlag string }{
+		{"sherpa-onnx-fire-red-asr2-ctc-zh_en-int8-2026-02-25", "--fire-red-asr-ctc="},
+		{"sherpa-onnx-nemo-ctc-en-conformer-medium", "--nemo-ctc-model="},
+		{"sherpa-onnx-zipformer-ctc-zh-2024", "--zipformer-ctc-model="},
+		{"sherpa-onnx-telespeech-ctc-int8", "--telespeech-ctc="},
+		{"sherpa-onnx-wenet-ctc-en", "--wenet-ctc-model="},
+		{"sherpa-onnx-dolphin-base-ctc-multi-lang", "--dolphin-model="},
+		{"sherpa-onnx-omnilingual-asr-ctc", "--omnilingual-asr-model="},
+		{"sherpa-onnx-tdnn-yesno", "--tdnn-model="},
+	}
+	for _, tc := range cases {
+		dir := writeNamedModelDir(t, tc.base, "model.int8.onnx", "tokens.txt")
+		args, err := detectModelArgs(dir)
+		if err != nil {
+			t.Errorf("%s: detection failed: %v", tc.base, err)
+			continue
+		}
+		joined := strings.Join(args, " ")
+		if !strings.Contains(joined, tc.wantFlag) || !strings.Contains(joined, "--tokens=") {
+			t.Errorf("%s: got %q, want %s", tc.base, joined, tc.wantFlag)
+		}
+	}
+}
+
+func TestDetectEncoderDecoderFamiliesBeforeWhisper(t *testing.T) {
+	// FireRedASR-AED / Canary share Whisper's encoder+decoder shape, so they must be
+	// disambiguated by name — not fall through to --whisper-encoder.
+	cases := []struct{ base, wantFlag string }{
+		{"sherpa-onnx-fire-red-asr-large-zh_en", "--fire-red-asr-encoder="},
+		{"sherpa-onnx-canary-180m-flash", "--canary-encoder="},
+	}
+	for _, tc := range cases {
+		dir := writeNamedModelDir(t, tc.base, "encoder.int8.onnx", "decoder.int8.onnx", "tokens.txt")
+		args, err := detectModelArgs(dir)
+		if err != nil {
+			t.Errorf("%s: detection failed: %v", tc.base, err)
+			continue
+		}
+		joined := strings.Join(args, " ")
+		if !strings.Contains(joined, tc.wantFlag) {
+			t.Errorf("%s: got %q, want %s", tc.base, joined, tc.wantFlag)
+		}
+		if strings.Contains(joined, "--whisper-") {
+			t.Errorf("%s must not be detected as Whisper: %q", tc.base, joined)
+		}
+	}
+}
+
+func TestDetectUnknownFamilyFailsCleanly(t *testing.T) {
+	// A model with tokens but no recognizable family → a clear SetupError, not a
+	// crash or wrong flags.
+	dir := writeModelDir(t, "some-random-model.onnx", "tokens.txt")
+	_, err := detectModelArgs(dir)
+	var setupErr *SetupError
+	if !errors.As(err, &setupErr) {
+		t.Fatalf("want a clean *SetupError, got %v", err)
+	}
+	if !strings.Contains(setupErr.Error(), "could not recognize") {
+		t.Errorf("expected a recognizable failure message, got %q", setupErr.Error())
+	}
+}
+
+func TestLocalTranscribeMissingTokens(t *testing.T) {
+	dir := writeModelDir(t, "encoder.onnx", "decoder.onnx", "joiner.onnx") // no tokens.txt
+	tr, _ := NewLocalTranscriber(LocalConfig{ModelPath: dir, runOutput: func(context.Context, string, ...string) ([]byte, error) { return nil, nil }, tempDir: func() (string, error) { return t.TempDir(), nil }})
+	_, err := tr.Transcribe(context.Background(), wavFixture())
+	var setupErr *SetupError
+	if !errors.As(err, &setupErr) {
+		t.Fatalf("want *SetupError for missing tokens, got %v", err)
+	}
+}
+
+func TestLocalTranscribeMissingBinary(t *testing.T) {
+	dir := writeModelDir(t, "preprocess.onnx", "encode.onnx", "uncached_decode.onnx", "cached_decode.onnx", "tokens.txt")
+	runOutput := func(context.Context, string, ...string) ([]byte, error) { return nil, exec.ErrNotFound }
+	tr, _ := NewLocalTranscriber(LocalConfig{ModelPath: dir, runOutput: runOutput, tempDir: func() (string, error) { return t.TempDir(), nil }})
+	_, err := tr.Transcribe(context.Background(), wavFixture())
+	var setupErr *SetupError
+	if !errors.As(err, &setupErr) {
+		t.Fatalf("want *SetupError for missing binary, got %v", err)
+	}
+}
+
+func TestParseSherpaOutput(t *testing.T) {
+	out := []byte("Started\nDone!\n\naudio.wav\n{\"lang\":\"\",\"text\":\" the quick brown fox \",\"tokens\":[]}\n----\nnum threads: 2")
+	if got := parseSherpaOutput(out); got != "the quick brown fox" {
+		t.Errorf("parsed %q", got)
+	}
+	if got := parseSherpaOutput([]byte("no json here")); got != "" {
+		t.Errorf("expected empty, got %q", got)
+	}
+}
+
+func TestNewLocalTranscriberRequiresModelPath(t *testing.T) {
+	_, err := NewLocalTranscriber(LocalConfig{})
+	var setupErr *SetupError
+	if !errors.As(err, &setupErr) {
+		t.Fatalf("want *SetupError, got %v", err)
+	}
+}

internal/dictation/transcriber_openai_realtime.go

@@ -0,0 +1,210 @@
+package dictation
+
+import (
+	"context"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"strings"
+
+	"github.com/coder/websocket"
+)
+
+// OpenAI Realtime transcription-only wants 24kHz PCM16 (§6b); the recorder is
+// built to match via the SampleRate hint.
+const openAIRealtimeSampleRate = 24000
+
+// OpenAIRealtimeConfig configures the OpenAI Realtime transcription transcriber
+// (§6b, the credential-reuse streaming alternative). Reuses the OpenAI key.
+type OpenAIRealtimeConfig struct {
+	APIKey string
+	Model  string // default "gpt-4o-transcribe"
+	// BaseURL overrides the wss endpoint (tests point it at a fake server).
+	BaseURL string
+}
+
+type openAIRealtimeTranscriber struct {
+	cfg OpenAIRealtimeConfig
+}
+
+// NewOpenAIRealtimeTranscriber builds the OpenAI Realtime streaming transcriber.
+func NewOpenAIRealtimeTranscriber(cfg OpenAIRealtimeConfig) (Transcriber, error) {
+	if strings.TrimSpace(cfg.APIKey) == "" {
+		return nil, &SetupError{
+			Tool: "OpenAI API key",
+			Hint: "set an OpenAI API key (OPENAI_API_KEY, or `zero auth`) to use OpenAI Realtime streaming dictation",
+		}
+	}
+	if cfg.Model == "" {
+		cfg.Model = "gpt-4o-transcribe"
+	}
+	if cfg.BaseURL == "" {
+		cfg.BaseURL = "wss://api.openai.com/v1/realtime?intent=transcription"
+	}
+	return &openAIRealtimeTranscriber{cfg: cfg}, nil
+}
+
+func (o *openAIRealtimeTranscriber) Transcribe(context.Context, []byte) (string, error) {
+	return "", ErrStreamingUnsupported
+}
+
+func (o *openAIRealtimeTranscriber) SampleRate() int { return openAIRealtimeSampleRate }
+
+func (o *openAIRealtimeTranscriber) StreamTranscribe(ctx context.Context, chunks <-chan []byte, onPartial func(string, bool)) (string, error) {
+	conn, _, err := websocket.Dial(ctx, o.cfg.BaseURL, &websocket.DialOptions{
+		HTTPHeader: http.Header{
+			"Authorization": {"Bearer " + o.cfg.APIKey},
+			"OpenAI-Beta":   {"realtime=v1"},
+		},
+	})
+	if err != nil {
+		return "", fmt.Errorf("connecting to OpenAI Realtime: %w", err)
+	}
+	defer conn.CloseNow()
+
+	// Configure a transcription-only session (pcm16 in, gpt-4o-transcribe).
+	sessionUpdate := map[string]any{
+		"type": "transcription_session.update",
+		"session": map[string]any{
+			"input_audio_format": "pcm16",
+			"input_audio_transcription": map[string]any{
+				"model": o.cfg.Model,
+			},
+		},
+	}
+	if err := writeJSON(ctx, conn, sessionUpdate); err != nil {
+		return "", fmt.Errorf("configuring OpenAI Realtime session: %w", err)
+	}
+
+	writeErrCh := make(chan error, 1)
+	go func() {
+		for chunk := range chunks {
+			appendMsg := map[string]any{
+				"type":  "input_audio_buffer.append",
+				"audio": base64.StdEncoding.EncodeToString(chunk),
+			}
+			if err := writeJSON(ctx, conn, appendMsg); err != nil {
+				writeErrCh <- err
+				return
+			}
+		}
+		// Commit the buffered audio to force final transcription of the utterance.
+		writeErrCh <- writeJSON(ctx, conn, map[string]any{"type": "input_audio_buffer.commit"})
+	}()
+
+	// OpenAI deltas are incremental (append), unlike Deepgram/sherpa's cumulative
+	// text. Accumulate completed segments plus the in-progress delta buffer.
+	var finalized, current strings.Builder
+	compose := func() string {
+		return strings.TrimSpace(finalized.String() + current.String())
+	}
+	committed := false
+	for {
+		typ, data, err := conn.Read(ctx)
+		if err != nil {
+			if websocket.CloseStatus(err) == websocket.StatusNormalClosure {
+				return compose(), nil
+			}
+			select {
+			case werr := <-writeErrCh:
+				if werr != nil {
+					err = werr
+				}
+			default:
+			}
+			return compose(), fmt.Errorf("OpenAI Realtime stream error: %w", err)
+		}
+		if typ != websocket.MessageText {
+			continue
+		}
+		evt := parseRealtimeEvent(data)
+		switch evt.kind {
+		case realtimeDelta:
+			current.WriteString(evt.text)
+			if onPartial != nil {
+				onPartial(compose(), false)
+			}
+		case realtimeCompleted:
+			// A completed item replaces the in-progress delta buffer with the
+			// server's authoritative transcript for that segment.
+			if evt.text != "" {
+				if finalized.Len() > 0 {
+					finalized.WriteString(" ")
+				}
+				finalized.WriteString(strings.TrimSpace(evt.text))
+			}
+			current.Reset()
+			if onPartial != nil {
+				onPartial(compose(), true)
+			}
+			// Once we've committed the buffer (user stopped) and the server has
+			// returned a completed transcription, the utterance is done.
+			if committed {
+				_ = conn.Close(websocket.StatusNormalClosure, "")
+				return compose(), nil
+			}
+		case realtimeCommitted:
+			committed = true
+		case realtimeError:
+			return compose(), fmt.Errorf("OpenAI Realtime error: %s", evt.text)
+		}
+		// The writer signals commit completion out of band; observe it so a
+		// stop with no further audio still flips `committed`.
+		select {
+		case werr := <-writeErrCh:
+			if werr == nil {
+				committed = true
+			}
+		default:
+		}
+	}
+}
+
+type realtimeEventKind int
+
+const (
+	realtimeOther realtimeEventKind = iota
+	realtimeDelta
+	realtimeCompleted
+	realtimeCommitted
+	realtimeError
+)
+
+type realtimeEvent struct {
+	kind realtimeEventKind
+	text string
+}
+
+func parseRealtimeEvent(data []byte) realtimeEvent {
+	var msg struct {
+		Type       string `json:"type"`
+		Delta      string `json:"delta"`
+		Transcript string `json:"transcript"`
+		Error      struct {
+			Message string `json:"message"`
+		} `json:"error"`
+	}
+	if err := json.Unmarshal(data, &msg); err != nil {
+		return realtimeEvent{kind: realtimeOther}
+	}
+	switch msg.Type {
+	case "conversation.item.input_audio_transcription.delta":
+		return realtimeEvent{kind: realtimeDelta, text: msg.Delta}
+	case "conversation.item.input_audio_transcription.completed":
+		return realtimeEvent{kind: realtimeCompleted, text: msg.Transcript}
+	case "input_audio_buffer.committed":
+		return realtimeEvent{kind: realtimeCommitted}
+	case "error":
+		return realtimeEvent{kind: realtimeError, text: msg.Error.Message}
+	}
+	return realtimeEvent{kind: realtimeOther}
+}
+
+func writeJSON(ctx context.Context, conn *websocket.Conn, v any) error {
+	data, err := json.Marshal(v)
+	if err != nil {
+		return err
+	}
+	return conn.Write(ctx, websocket.MessageText, data)
+}

internal/dictation/transcriber_stream_test.go

@@ -0,0 +1,231 @@
+package dictation
+
+import (
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strconv"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/coder/websocket"
+)
+
+// wsTestServer runs handler over a real localhost websocket, returning a wss->ws
+// base URL the transcribers can dial. Exercising the real coder/websocket client
+// against a real server is the closest unit test to the wire protocol.
+func wsTestServer(t *testing.T, handler func(ctx context.Context, c *websocket.Conn)) string {
+	t.Helper()
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		c, err := websocket.Accept(w, r, nil)
+		if err != nil {
+			return
+		}
+		handler(r.Context(), c)
+	}))
+	t.Cleanup(srv.Close)
+	return "ws" + strings.TrimPrefix(srv.URL, "http")
+}
+
+func TestDeepgramStreamTranscribe(t *testing.T) {
+	var gotAuth string
+	url := wsTestServer(t, func(ctx context.Context, c *websocket.Conn) {
+		defer c.Close(websocket.StatusNormalClosure, "")
+		// Read audio frames until CloseStream, then emit interim + final results.
+		for {
+			typ, data, err := c.Read(ctx)
+			if err != nil {
+				return
+			}
+			if typ == websocket.MessageText && strings.Contains(string(data), "CloseStream") {
+				break
+			}
+		}
+		_ = c.Write(ctx, websocket.MessageText, []byte(`{"type":"Results","is_final":false,"channel":{"alternatives":[{"transcript":"hello"}]}}`))
+		_ = c.Write(ctx, websocket.MessageText, []byte(`{"type":"Results","is_final":true,"channel":{"alternatives":[{"transcript":"hello world"}]}}`))
+	})
+
+	tr, err := NewDeepgramTranscriber(DeepgramConfig{APIKey: "dg-key", BaseURL: url})
+	if err != nil {
+		t.Fatal(err)
+	}
+	_ = gotAuth
+
+	var partials []string
+	chunks := make(chan []byte, 2)
+	chunks <- make([]byte, 320)
+	close(chunks)
+	final, err := tr.StreamTranscribe(context.Background(), chunks, func(text string, _ bool) {
+		partials = append(partials, text)
+	})
+	if err != nil {
+		t.Fatalf("StreamTranscribe: %v", err)
+	}
+	if final != "hello world" {
+		t.Errorf("final = %q, want 'hello world'", final)
+	}
+	if len(partials) == 0 || partials[0] != "hello" {
+		t.Errorf("expected an interim 'hello' partial, got %v", partials)
+	}
+}
+
+func TestDeepgramSampleRateDefault(t *testing.T) {
+	tr, _ := NewDeepgramTranscriber(DeepgramConfig{APIKey: "k"})
+	if RequiredSampleRate(tr) != DefaultSampleRate {
+		t.Errorf("Deepgram sample rate = %d, want %d", RequiredSampleRate(tr), DefaultSampleRate)
+	}
+}
+
+func TestDeepgramMissingKey(t *testing.T) {
+	if _, err := NewDeepgramTranscriber(DeepgramConfig{}); err == nil {
+		t.Fatal("expected setup error for missing key")
+	}
+}
+
+func TestOpenAIRealtimeStreamTranscribe(t *testing.T) {
+	url := wsTestServer(t, func(ctx context.Context, c *websocket.Conn) {
+		defer c.Close(websocket.StatusNormalClosure, "")
+		committed := false
+		for {
+			typ, data, err := c.Read(ctx)
+			if err != nil {
+				return
+			}
+			if typ != websocket.MessageText {
+				continue
+			}
+			var msg struct {
+				Type string `json:"type"`
+			}
+			_ = json.Unmarshal(data, &msg)
+			switch msg.Type {
+			case "transcription_session.update":
+				// Emit incremental deltas as if audio were flowing.
+				_ = c.Write(ctx, websocket.MessageText, []byte(`{"type":"conversation.item.input_audio_transcription.delta","delta":"the "}`))
+				_ = c.Write(ctx, websocket.MessageText, []byte(`{"type":"conversation.item.input_audio_transcription.delta","delta":"answer"}`))
+			case "input_audio_buffer.commit":
+				committed = true
+				_ = c.Write(ctx, websocket.MessageText, []byte(`{"type":"input_audio_buffer.committed"}`))
+				_ = c.Write(ctx, websocket.MessageText, []byte(`{"type":"conversation.item.input_audio_transcription.completed","transcript":"the answer"}`))
+			}
+			_ = committed
+		}
+	})
+
+	tr, err := NewOpenAIRealtimeTranscriber(OpenAIRealtimeConfig{APIKey: "sk-key", BaseURL: url})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if RequiredSampleRate(tr) != openAIRealtimeSampleRate {
+		t.Errorf("OpenAI Realtime sample rate = %d, want %d", RequiredSampleRate(tr), openAIRealtimeSampleRate)
+	}
+
+	chunks := make(chan []byte, 1)
+	chunks <- make([]byte, 480)
+	close(chunks)
+	done := make(chan struct{})
+	var final string
+	var ferr error
+	go func() {
+		final, ferr = tr.StreamTranscribe(context.Background(), chunks, func(string, bool) {})
+		close(done)
+	}()
+	select {
+	case <-done:
+	case <-time.After(5 * time.Second):
+		t.Fatal("StreamTranscribe did not complete")
+	}
+	if ferr != nil {
+		t.Fatalf("StreamTranscribe: %v", ferr)
+	}
+	if final != "the answer" {
+		t.Errorf("final = %q, want 'the answer'", final)
+	}
+}
+
+// TestLocalStreamingAccumulatesSegments is the regression for the "text vanishes
+// on stop" bug: the sherpa server reports text PER SEGMENT and resets it to "" when
+// it endpoints, so the transcriber must accumulate across segments rather than let
+// a new (empty) segment overwrite everything already recognized.
+func TestLocalStreamingAccumulatesSegments(t *testing.T) {
+	url := wsTestServer(t, func(ctx context.Context, c *websocket.Conn) {
+		defer c.Close(websocket.StatusNormalClosure, "")
+		go func() { // drain the client's audio + "Done"
+			for {
+				if _, _, err := c.Read(ctx); err != nil {
+					return
+				}
+			}
+		}()
+		for _, m := range []string{
+			`{"text":" hello","segment":0,"is_final":false}`,
+			`{"text":" hello world","segment":0,"is_final":true}`,
+			`{"text":"","segment":1,"is_final":false}`, // endpoint reset — must NOT wipe seg 0
+			`{"text":" foo bar","segment":1,"is_final":true}`,
+			`{"text":"","segment":2,"is_final":true}`, // trailing empty segment at stop
+		} {
+			_ = c.Write(ctx, websocket.MessageText, []byte(m))
+		}
+		_ = c.Write(ctx, websocket.MessageText, []byte("Done!"))
+	})
+
+	colon := strings.LastIndex(url, ":")
+	port, err := strconv.Atoi(url[colon+1:])
+	if err != nil {
+		t.Fatalf("parsing test server port from %q: %v", url, err)
+	}
+	mgr := NewServerManager(ServerConfig{
+		ModelPath:   streamingModelDir(t),
+		Port:        port,
+		starter:     func(commandSpec) (processHandle, io.ReadCloser, error) { return newFakeProcess(), nil, nil },
+		healthCheck: func(context.Context, int) error { return nil },
+		aliveCheck:  func(int) bool { return false },
+	})
+	tr := NewLocalStreamingTranscriber(mgr)
+
+	chunks := make(chan []byte)
+	close(chunks) // no audio; the writer immediately sends "Done"
+	var partials []string
+	text, err := tr.StreamTranscribe(context.Background(), chunks, func(s string, _ bool) {
+		partials = append(partials, s)
+	})
+	if err != nil {
+		t.Fatalf("StreamTranscribe: %v", err)
+	}
+	if text != "hello world foo bar" {
+		t.Errorf("final text = %q, want %q", text, "hello world foo bar")
+	}
+	// Once text has appeared, no later partial may go empty — that would be the
+	// segment-reset wiping the transcript, the exact bug this guards.
+	seen := false
+	for _, p := range partials {
+		if p != "" {
+			seen = true
+		}
+		if seen && p == "" {
+			t.Errorf("transcript went empty after text appeared; partials=%v", partials)
+		}
+	}
+}
+
+func TestParseDeepgramResultIgnoresNonResults(t *testing.T) {
+	if _, _, ok := parseDeepgramResult([]byte(`{"type":"Metadata"}`)); ok {
+		t.Error("Metadata messages should be ignored")
+	}
+	tr, final, ok := parseDeepgramResult([]byte(`{"type":"Results","is_final":true,"channel":{"alternatives":[{"transcript":"hi"}]}}`))
+	if !ok || tr != "hi" || !final {
+		t.Errorf("parse = (%q,%v,%v)", tr, final, ok)
+	}
+}
+
+func TestParseRealtimeEvent(t *testing.T) {
+	if e := parseRealtimeEvent([]byte(`{"type":"conversation.item.input_audio_transcription.delta","delta":"x"}`)); e.kind != realtimeDelta || e.text != "x" {
+		t.Errorf("delta parse: %+v", e)
+	}
+	if e := parseRealtimeEvent([]byte(`{"type":"error","error":{"message":"boom"}}`)); e.kind != realtimeError || e.text != "boom" {
+		t.Errorf("error parse: %+v", e)
+	}
+}

internal/doctor/doctor.go

@@ -14,6 +14,7 @@ import (
 
 	"github.com/Gitlawb/zero/internal/config"
 	"github.com/Gitlawb/zero/internal/modelregistry"
+	"github.com/Gitlawb/zero/internal/oauth"
 	"github.com/Gitlawb/zero/internal/providerhealth"
 	"github.com/Gitlawb/zero/internal/redaction"
 )
@@ -143,12 +144,19 @@ func providerConfigCheck(profile config.ProviderProfile) Check {
 	// Report credential PRESENCE, never the value. Reported under a non-sensitive
 	// key ("credentialConfigured"): the prior "apiKey" key was itself sensitive, so
 	// check()'s redaction scrubbed the indicator to [REDACTED] — making "set"/"not
-	// set" invisible. A profile can authenticate via a raw auth-header value instead
-	// of APIKey, and both are trimmed so a whitespace-only value reads "not set"
-	// (matching ProviderSnapshot.APIKeySet).
+	// set" invisible. HasConfiguredCredential is the shared definition of
+	// "key-authed" (inline key, raw auth header, or a key in the encrypted
+	// credential store), matching ProviderSnapshot.APIKeySet — checking only the
+	// inline fields made doctor and `zero providers list` disagree about the
+	// same stored-key profile. A stored OAuth login counts too: a keyless
+	// token-login provider (e.g. ChatGPT) is fully able to make requests and
+	// must not fail the one tool meant to verify setup.
 	credential := "not set"
-	if strings.TrimSpace(profile.APIKey) != "" || strings.TrimSpace(profile.AuthHeaderValue) != "" {
+	switch {
+	case profile.HasConfiguredCredential():
 		credential = "set"
+	case providerHasStoredOAuthLogin(profile):
+		credential = "oauth login"
 	}
 	details := map[string]any{
 		"name":                 profile.Name,
@@ -169,6 +177,22 @@ func providerConfigCheck(profile config.ProviderProfile) Check {
 	return check("provider.config", "Provider config", StatusPass, fmt.Sprintf("Provider config loaded for %s.", providerName(profile)), details)
 }
 
+// providerHasStoredOAuthLogin reports whether the token store holds a login for
+// any of the profile's candidates — the same candidate set and normalized-key
+// matching the runtime resolver uses. Errors degrade to false.
+func providerHasStoredOAuthLogin(profile config.ProviderProfile) bool {
+	candidates := profile.OAuthLoginCandidates()
+	if len(candidates) == 0 {
+		return false
+	}
+	store, err := oauth.NewStore(oauth.StoreOptions{})
+	if err != nil {
+		return false
+	}
+	_, _, ok := oauth.FirstStored(store, candidates)
+	return ok
+}
+
 // localProviderBaseURL reports whether the configured base_url is a loopback host
 // (a keyless local provider like Ollama/LM Studio), which needs no API key.
 func localProviderBaseURL(baseURL string) bool {

internal/mcp/config.go

@@ -31,6 +31,11 @@ type Server struct {
 	Auth     string
 	OAuth    *OAuthConfig
 	Identity string
+	// UnconfiguredDefault is true when this server is one of Zero's built-in
+	// defaults (e.g. keyless Firecrawl) that the user never touched in their
+	// config — no credentials, no overrides. Callers use it to avoid warning
+	// loudly when a server nobody configured fails to connect.
+	UnconfiguredDefault bool
 }
 
 func NormalizeConfig(cfg config.MCPConfig) ([]Server, error) {
@@ -74,15 +79,16 @@ func normalizeServer(name string, raw config.MCPServerConfig) (Server, error) {
 
 	auth := strings.ToLower(strings.TrimSpace(raw.Auth))
 	server := Server{
-		Name:    name,
-		Type:    serverType,
-		Command: strings.TrimSpace(raw.Command),
-		Args:    trimStringSlice(raw.Args),
-		Env:     copyStringMap(raw.Env),
-		URL:     strings.TrimSpace(raw.URL),
-		Headers: copyStringMap(raw.Headers),
-		Auth:    auth,
-		OAuth:   normalizeOAuthConfig(raw.OAuth),
+		Name:                name,
+		Type:                serverType,
+		Command:             strings.TrimSpace(raw.Command),
+		Args:                trimStringSlice(raw.Args),
+		Env:                 copyStringMap(raw.Env),
+		URL:                 strings.TrimSpace(raw.URL),
+		Headers:             copyStringMap(raw.Headers),
+		Auth:                auth,
+		OAuth:               normalizeOAuthConfig(raw.OAuth),
+		UnconfiguredDefault: config.IsUnconfiguredDefault(name, raw),
 	}
 
 	switch server.Type {

internal/mcp/config_test.go

@@ -88,6 +88,33 @@ func TestNormalizeConfigValidatesTransportBoundaries(t *testing.T) {
 	}
 }
 
+func TestNormalizeConfigFlagsUnconfiguredDefault(t *testing.T) {
+	cfg := config.MCPConfig{Servers: map[string]config.MCPServerConfig{
+		"firecrawl": config.DefaultMCPServers()["firecrawl"],
+		"web": {
+			Type: "http",
+			URL:  "https://example.com/mcp",
+		},
+	}}
+
+	servers, err := NormalizeConfig(cfg)
+	if err != nil {
+		t.Fatalf("NormalizeConfig() error = %v", err)
+	}
+
+	byName := make(map[string]Server, len(servers))
+	for _, server := range servers {
+		byName[server.Name] = server
+	}
+
+	if !byName["firecrawl"].UnconfiguredDefault {
+		t.Fatal("an untouched firecrawl default should be flagged UnconfiguredDefault")
+	}
+	if byName["web"].UnconfiguredDefault {
+		t.Fatal("a server the user configured must not be flagged UnconfiguredDefault")
+	}
+}
+
 func TestServerIdentityChangesWithTransportFields(t *testing.T) {
 	for _, tc := range []struct {
 		name   string

internal/mcp/registry.go

@@ -35,6 +35,10 @@ type RegisterOptions struct {
 type SkippedServer struct {
 	Name string
 	Err  error
+	// UnconfiguredDefault mirrors Server.UnconfiguredDefault: true when this
+	// server is an out-of-the-box default the user never configured, so a
+	// caller can skip warning loudly about it.
+	UnconfiguredDefault bool
 }
 
 type Runtime struct {
@@ -148,7 +152,7 @@ func RegisterTools(ctx context.Context, registry *tools.Registry, cfg config.MCP
 	for index, server := range servers {
 		res := results[index]
 		if res.err != nil {
-			runtime.skipped = append(runtime.skipped, SkippedServer{Name: server.Name, Err: res.err})
+			runtime.skipped = append(runtime.skipped, SkippedServer{Name: server.Name, Err: res.err, UnconfiguredDefault: server.UnconfiguredDefault})
 			continue
 		}
 		serverTools, validateErr := buildServerTools(registry, server, res.remote, res.client, options, stagedNames)
@@ -157,7 +161,7 @@ func RegisterTools(ctx context.Context, registry *tools.Registry, cfg config.MCP
 				res.cancel()
 			}
 			_ = res.client.Close()
-			runtime.skipped = append(runtime.skipped, SkippedServer{Name: server.Name, Err: validateErr})
+			runtime.skipped = append(runtime.skipped, SkippedServer{Name: server.Name, Err: validateErr, UnconfiguredDefault: server.UnconfiguredDefault})
 			continue
 		}
 		runtime.clients = append(runtime.clients, res.client)

internal/mcp/registry_test.go

@@ -153,6 +153,47 @@ func TestRegisterToolsSkipsUnreachableServerAndKeepsOthers(t *testing.T) {
 	}
 }
 
+func TestRegisterToolsFlagsUnconfiguredDefaultOnSkip(t *testing.T) {
+	// firecrawl is seeded by config.DefaultMCPServers with no credentials; when a
+	// user never configures it, a connect failure (e.g. the real HTTP 401 from
+	// issue #552) must be recorded as UnconfiguredDefault so callers can avoid
+	// warning about a server the user never asked for. "custom" is configured by
+	// the user and must NOT be flagged even though it also fails to connect.
+	registry := tools.NewRegistry()
+
+	runtime, err := RegisterTools(context.Background(), registry, config.MCPConfig{Servers: map[string]config.MCPServerConfig{
+		"firecrawl": config.DefaultMCPServers()["firecrawl"],
+		"custom":    {Type: "stdio", Command: "custom-mcp"},
+	}}, RegisterOptions{
+		ClientFactory: func(_ context.Context, server Server) (ToolClient, error) {
+			return nil, errors.New(server.Name + " connect failed")
+		},
+	})
+	if err != nil {
+		t.Fatalf("RegisterTools returned error, want a skip: %v", err)
+	}
+	defer runtime.Close()
+
+	byName := make(map[string]SkippedServer)
+	for _, skipped := range runtime.Skipped() {
+		byName[skipped.Name] = skipped
+	}
+	firecrawl, ok := byName["firecrawl"]
+	if !ok {
+		t.Fatalf("Skipped() = %#v, want an entry for firecrawl", runtime.Skipped())
+	}
+	if !firecrawl.UnconfiguredDefault {
+		t.Fatalf("Skipped()[firecrawl] = %#v, want UnconfiguredDefault", firecrawl)
+	}
+	custom, ok := byName["custom"]
+	if !ok {
+		t.Fatalf("Skipped() = %#v, want an entry for custom", runtime.Skipped())
+	}
+	if custom.UnconfiguredDefault {
+		t.Fatalf("Skipped()[custom] = %#v, want a user-configured server not flagged", custom)
+	}
+}
+
 func TestRegisterToolsKeepsPriorStateAndReachableServersWhenOneIsSkipped(t *testing.T) {
 	// A tool that predates registration must survive, the reachable server's tools
 	// must register, and the unreachable server is skipped (recorded), not fatal.

internal/oauth/encrypt.go

@@ -122,17 +122,17 @@ func createSecretFile(path string) ([]byte, error) {
 		if !errors.Is(err, os.ErrExist) && !errors.Is(err, os.ErrPermission) {
 			return nil, fmt.Errorf("oauth: create token secret lock: %w", err)
 		}
+		// Remember the lock-creation error itself rather than a subsequent
+		// "secret file doesn't exist yet" read error -- otherwise a real
+		// contention/ACL problem is masked by the expected-while-waiting
+		// ErrNotExist once the retries are exhausted.
+		lastErr = err
 		if data, rerr := readSecretFileRetry(path); rerr == nil {
 			return data, nil
-		} else {
-			lastErr = rerr
 		}
 		time.Sleep(secretRetryDelay)
 	}
-	if lastErr != nil {
-		return nil, fmt.Errorf("oauth: timed out waiting for token secret %s: %w", path, lastErr)
-	}
-	return nil, fmt.Errorf("oauth: timed out waiting for token secret lock %s", lockPath)
+	return nil, fmt.Errorf("oauth: timed out waiting for token secret %s: %w", path, lastErr)
 }
 
 func writeNewSecretFile(path string) ([]byte, error) {

internal/oauth/store.go

@@ -38,8 +38,16 @@ func ValidateKey(key string) error {
 	return nil
 }
 
-// ProviderKey builds the store key for a provider login.
-func ProviderKey(name string) string { return KeyPrefixProvider + name }
+// ProviderKey builds the store key for a provider login, normalizing the name
+// to lower case. Every write (Manager.Login, the ChatGPT flow) and every
+// lookup (FirstStored, GetFresh, logout, status filters) funnels through here,
+// so normalizing at this one choke point keeps them symmetric: without it,
+// `zero auth login xAI` stored "provider:xAI" while the profile scaffolded for
+// it looked up "provider:xai" case-sensitively — a fresh, successful login
+// that was invisible to the runtime.
+func ProviderKey(name string) string {
+	return KeyPrefixProvider + strings.ToLower(strings.TrimSpace(name))
+}
 
 // FirstStored returns the token and its ProviderKey for the FIRST candidate name
 // that has a token in the store, with ok=false when none do. Callers pass

internal/oauth/store_test.go

@@ -126,3 +126,20 @@ func TestResolveStorePathHonorsOverride(t *testing.T) {
 		t.Fatalf("path = %q, want %q", path, override)
 	}
 }
+
+// TestProviderKeyNormalizesCase: every provider-login write and lookup funnels
+// through ProviderKey, so `zero auth login xAI` and the scaffolded profile's
+// candidate "xai" must resolve to the SAME store entry — the raw-typed casing
+// previously produced an invisible login.
+func TestProviderKeyNormalizesCase(t *testing.T) {
+	if got := ProviderKey(" xAI "); got != "provider:xai" {
+		t.Fatalf("ProviderKey must trim and lower-case, got %q", got)
+	}
+	store, _ := newTestStore(t)
+	if err := store.Save(ProviderKey("xAI"), Token{AccessToken: "tok"}); err != nil {
+		t.Fatalf("save: %v", err)
+	}
+	if _, key, ok := FirstStored(store, []string{"xai"}); !ok || key != "provider:xai" {
+		t.Fatalf("candidate \"xai\" must find the mixed-case login, ok=%v key=%q", ok, key)
+	}
+}

internal/providercatalog/catalog.go

@@ -48,6 +48,14 @@ type Descriptor struct {
 	SupportedAPIFormats []APIFormat
 	Aliases             []string
 
+	// Custom marks the "bring your own endpoint" catalog entries
+	// (custom-openai-compatible, custom-anthropic-compatible). Unlike every other
+	// descriptor, RequiresAuth here is just a template default for the credential
+	// wizard step, not a fact about the user's actual endpoint — a custom target may
+	// or may not need auth, so callers deciding whether a *saved profile* is missing
+	// a credential must not treat RequiresAuth as authoritative for these entries.
+	Custom bool
+
 	// OAuth reports that this provider offers an in-app OAuth login that yields a
 	// credential usable for model calls (browser PKCE and/or device code). Only
 	// set for providers where this actually works (not subscription-via-proxy).
@@ -89,8 +97,8 @@ func RuntimeUnsupportedReason(descriptor Descriptor) string {
 var descriptors = []Descriptor{
 	// GitLawb OpenGateway — the recommended default. An OpenAI-compatible gateway
 	// that smart-routes by model id across upstream providers (xiaomi-mimo,
-	// minimax, qwen, google, nvidia, z-ai). Flat /v1/chat/completions with a
-	// Bearer ogw_live_… key; listed first and badged in every picker.
+	// minimax, qwen, google, nvidia, tencent, z-ai). Flat /v1/chat/completions
+	// with a Bearer ogw_live_… key; listed first and badged in every picker.
 	recommended(openAICompat("gitlawb-opengateway", "GitLawb OpenGateway", "https://opengateway.gitlawb.com/v1", "mimo-v2.5-pro", []string{"GITLAWB_OPENGATEWAY_API_KEY"}, "gitlawb opengateway", "opengateway")),
 	openAI("openai", "OpenAI", "https://api.openai.com/v1", "gpt-4.1", []string{"OPENAI_API_KEY"}),
 	anthropic("anthropic", "Anthropic", "https://api.anthropic.com", "claude-sonnet-4.5", []string{"ANTHROPIC_API_KEY"}),
@@ -140,6 +148,7 @@ var descriptors = []Descriptor{
 	openAICompat("kilocode", "KiloCode", "https://api.kilo.ai/api/gateway", "anthropic/claude-sonnet-4.6", []string{"KILO_API_KEY"}, "kilo", "kilo gateway"),
 	openAICompat("opencode", "OpenCode Zen", "https://opencode.ai/zen/v1", "deepseek-v4-flash", []string{"OPENCODE_API_KEY"}, "opencode zen"),
 	openAICompat("opencode-go", "OpenCode Go", "https://opencode.ai/zen/go/v1", "deepseek-v4-pro", []string{"OPENCODE_API_KEY"}, "opencode go"),
+	anthropicCompat("opencode-go-anthropic-compatible", "OpenCode Go Anthropic-compatible", "https://opencode.ai/zen/go", "minimax-m3", []string{"OPENCODE_API_KEY"}),
 	openAICompat("atomic-chat", "Atomic Chat", "https://api.atomic.chat/v1", "gpt-4.1", []string{"ATOMIC_CHAT_API_KEY"}),
 	// ChatGPT subscription via a local OAuth proxy. A ChatGPT (Plus/Pro) OAuth
 	// token only works against ChatGPT's own backend (which is Cloudflare-gated to
@@ -148,8 +157,16 @@ var descriptors = []Descriptor{
 	// endpoint. Local (no API key — the proxy authenticates); override the base URL
 	// for your proxy's port. See docs/oauth-subscriptions.md.
 	localOpenAI("chatgpt-proxy", "ChatGPT (local OAuth proxy)", "http://localhost:10531/v1", "gpt-5", "chatgpt"),
-	openAICompat("custom-openai-compatible", "Custom OpenAI-compatible", "https://example.invalid/v1", "custom-model", []string{"OPENAI_API_KEY"}, "custom openai compatible"),
-	anthropicCompat("custom-anthropic-compatible", "Custom Anthropic-compatible", "https://example.invalid/anthropic", "custom-model", []string{"ANTHROPIC_API_KEY"}, "custom anthropic compatible"),
+	func() Descriptor {
+		d := openAICompat("custom-openai-compatible", "Custom OpenAI-compatible", "https://example.invalid/v1", "custom-model", []string{"OPENAI_API_KEY"}, "custom openai compatible")
+		d.Custom = true
+		return d
+	}(),
+	func() Descriptor {
+		d := anthropicCompat("custom-anthropic-compatible", "Custom Anthropic-compatible", "https://example.invalid/anthropic", "custom-model", []string{"ANTHROPIC_API_KEY"}, "custom anthropic compatible")
+		d.Custom = true
+		return d
+	}(),
 }
 
 func All() []Descriptor {

internal/providercatalog/catalog_test.go

@@ -40,6 +40,7 @@ var expectedCatalogIDs = []string{
 	"kilocode",
 	"opencode",
 	"opencode-go",
+	"opencode-go-anthropic-compatible",
 	"atomic-chat",
 	"chatgpt-proxy",
 	"custom-openai-compatible",
@@ -291,7 +292,7 @@ func TestListByTransportPreservesCatalogOrder(t *testing.T) {
 		TransportGoogle:          {"google"},
 		TransportBedrock:         {"bedrock"},
 		TransportVertex:          {"vertex"},
-		TransportAnthropicCompat: {"minimax", "minimaxi-cn", "custom-anthropic-compatible"},
+		TransportAnthropicCompat: {"minimax", "minimaxi-cn", "opencode-go-anthropic-compatible", "custom-anthropic-compatible"},
 		TransportOpenAICompat:    {"gitlawb-opengateway", "ollama-cloud", "ollama", "lmstudio", "openrouter", "huggingface", "chatgpt", "groq", "deepseek", "together", "dashscope", "moonshot", "longcat", "nvidia-nim", "mistral", "github", "xai", "venice", "xiaomi-mimo", "bankr", "zai", "zai-cn", "kilocode", "opencode", "opencode-go", "atomic-chat", "chatgpt-proxy", "custom-openai-compatible"},
 	}
 

internal/providermodelcatalog/catalog.go

@@ -140,12 +140,13 @@ var curatedModels = map[string][]Model{
 	"zai":    zaiCuratedModels,
 	"zai-cn": zaiCuratedModels,
 	// OpenGateway smart-routes by model id across its upstream providers
-	// (see /health: xiaomi-mimo, minimax, qwen, google, nvidia, z-ai). These are
-	// the curated coding defaults; the gateway accepts any model its upstreams
-	// expose, so users can also type an id the picker doesn't list.
+	// (see /health: xiaomi-mimo, minimax, qwen, google, nvidia, tencent, z-ai).
+	// These are the curated coding defaults; the gateway accepts any model its
+	// upstreams expose, so users can also type an id the picker doesn't list.
 	"gitlawb-opengateway": {
 		{ID: "mimo-v2.5-pro", Description: "catalog default (Xiaomi MiMo)"},
 		{ID: "mimo-v2.5-pro-ultraspeed", Description: "fast model (Xiaomi MiMo)"},
+		{ID: "tencent/hy3", Description: "free Tencent HY3 model"},
 		{ID: "MiniMax-M3", Description: "MiniMax model"},
 		{ID: "qwen-plus", Description: "Qwen model"},
 		{ID: "gemini-2.5-pro", Description: "long-context model (Google)"},
@@ -156,6 +157,12 @@ var curatedModels = map[string][]Model{
 		{ID: "gpt-4.1", Description: "catalog default"},
 		{ID: "gpt-4o-mini", Description: "fast model"},
 	},
+	"opencode-go-anthropic-compatible": {
+		{ID: "minimax-m3", Description: "MiniMax M3: default"},
+		{ID: "minimax-m2.7", Description: "MiniMax M2.7: coding model"},
+		{ID: "qwen3.7-plus", Description: "Qwen 3.7 Plus: balanced model"},
+		{ID: "qwen3.7-max", Description: "Qwen 3.7 Max: strong model"},
+	},
 	"custom-openai-compatible": {
 		{ID: "custom-model", Description: "custom endpoint model"},
 	},
@@ -166,13 +173,13 @@ var curatedModels = map[string][]Model{
 
 func Models(provider providercatalog.Descriptor) []Model {
 	if models, ok := curatedModels[provider.ID]; ok {
-		return dedupeModels(provider.DefaultModel, models)
+		return FilterModelsForProvider(provider.ID, dedupeModels(provider.DefaultModel, models))
 	}
 	models := registryModels(provider)
 	if len(models) > 0 {
-		return dedupeModels(provider.DefaultModel, models)
+		return FilterModelsForProvider(provider.ID, dedupeModels(provider.DefaultModel, models))
 	}
-	return dedupeModels(provider.DefaultModel, nil)
+	return FilterModelsForProvider(provider.ID, dedupeModels(provider.DefaultModel, nil))
 }
 
 func registryModels(provider providercatalog.Descriptor) []Model {

internal/providermodelcatalog/catalog_test.go

@@ -47,6 +47,16 @@ func TestModelsAreProviderScoped(t *testing.T) {
 			want:     []string{"glm-4.5", "glm-4.6", "glm-4.5-air", "glm-z1-air"},
 			notWant:  []string{"gpt-4.1", "claude-sonnet-4.5"},
 		},
+		{
+			provider: "gitlawb-opengateway",
+			want:     []string{"mimo-v2.5-pro", "tencent/hy3"},
+			notWant:  []string{"openai/gpt-4.1", "claude-sonnet-4.5"},
+		},
+		{
+			provider: "opencode-go-anthropic-compatible",
+			want:     []string{"minimax-m3", "minimax-m2.7", "qwen3.7-plus", "qwen3.7-max"},
+			notWant:  []string{"gpt-4.1", "claude-sonnet-4.5", "deepseek-chat"},
+		},
 	}
 
 	for _, tt := range tests {

internal/providermodelcatalog/filter.go

@@ -1,6 +1,38 @@
 package providermodelcatalog
 
-import "strings"
+import (
+	"strings"
+
+	"github.com/Gitlawb/zero/internal/providercatalog"
+)
+
+// ModelIDAllowedForProvider reports whether a model ID is permitted for the
+// given provider under provider-specific allow/block rules.
+// For opencode-go-anthropic-compatible: only Qwen and MiniMax model IDs are allowed.
+// Allows ANY model by default
+func ModelIDAllowedForProvider(providerID, modelID string) bool {
+	modelID = strings.ToLower(strings.TrimSpace(modelID))
+	if modelID == "" {
+		return false
+	}
+	switch providercatalog.NormalizeID(providerID) {
+	case "opencode-go-anthropic-compatible":
+		return strings.Contains(modelID, "qwen") || strings.Contains(modelID, "minimax")
+	default:
+		return true
+	}
+}
+
+// FilterModelsForProvider filters a model slice by ModelIDAllowedForProvider.
+func FilterModelsForProvider(providerID string, models []Model) []Model {
+	result := make([]Model, 0, len(models))
+	for _, model := range models {
+		if ModelIDAllowedForProvider(providerID, model.ID) {
+			result = append(result, model)
+		}
+	}
+	return result
+}
 
 func IsCodingModel(model Model) bool {
 	if IsKnownNonCodingModelID(model.ID) {
@@ -31,7 +63,7 @@ func LooksLikeCodingModelID(id string) bool {
 		"mistral", "codestral", "devstral", "magistral", "ministral",
 		"grok", "glm", "command", "nemotron", "mixtral", "coder",
 		"code", "chat", "instruct", "reasoner", "reasoning", "mimo",
-		"maverick", "scout", "bankr",
+		"hy3", "tencent", "maverick", "scout", "bankr",
 	} {
 		if strings.Contains(normalized, term) {
 			return true
@@ -57,6 +89,67 @@ func IsKnownNonCodingModelID(id string) bool {
 	return false
 }
 
+// IsSTTModel reports whether a model transcribes speech to text — the models
+// IsKnownNonCodingModelID filters OUT of the coding picker, filtered back IN for
+// the /stt-model picker.
+//
+// The reliable signal is the model's declared modalities, not its name: a
+// transcriber consumes audio and emits text. Anything that emits audio is
+// text-to-speech or speech-to-speech, never a transcriber, so audio output is a
+// hard disqualifier. Only when a catalog entry carries no usable modality
+// metadata (common for the Groq/OpenAI transcription models, which models.dev
+// lists sparsely) do we fall back to a name heuristic.
+func IsSTTModel(model Model) bool {
+	audioIn := containsFold(model.InputModalities, "audio")
+	audioOut := containsFold(model.OutputModalities, "audio")
+	textOut := containsFold(model.OutputModalities, "text")
+
+	// Emits audio → TTS or speech-to-speech, regardless of a transcription-like
+	// name. This is what stops gpt-4o-audio-preview / *-realtime from slipping in.
+	if audioOut {
+		return false
+	}
+	// Consumes audio and emits text (or emits nothing explicit) → transcriber.
+	if audioIn && (textOut || len(model.OutputModalities) == 0) {
+		return true
+	}
+	// Declares input modalities but none is audio → cannot be speech-to-text,
+	// whatever it is called.
+	if len(model.InputModalities) > 0 && !audioIn {
+		return false
+	}
+	// No usable modality metadata: fall back to the name heuristic.
+	return IsSTTModelID(model.ID)
+}
+
+// IsSTTModelID is the name-only heuristic used when a catalog entry declares no
+// modalities. It matches the known transcription model families and explicitly
+// rejects text-to-speech names, so it never confuses a TTS model for a
+// transcriber. Weaker than the modality signal in IsSTTModel — a fallback, not
+// the primary test.
+func IsSTTModelID(id string) bool {
+	normalized := strings.ToLower(strings.TrimSpace(id))
+	if normalized == "" {
+		return false
+	}
+	// Text-to-speech / speech-synthesis names are never transcription.
+	for _, tts := range []string{"tts", "text-to-speech"} {
+		if strings.Contains(normalized, tts) {
+			return false
+		}
+	}
+	for _, term := range []string{
+		"whisper", "transcribe", "transcription",
+		"scribe", "parakeet", "canary", "moonshine",
+		"sense-voice", "sensevoice", "wav2vec", "conformer",
+	} {
+		if strings.Contains(normalized, term) {
+			return true
+		}
+	}
+	return false
+}
+
 func hasCodingTag(tags []string) bool {
 	for _, tag := range tags {
 		normalized := strings.ToLower(strings.TrimSpace(tag))

internal/providermodelcatalog/filter_test.go

@@ -0,0 +1,108 @@
+package providermodelcatalog
+
+import (
+	"testing"
+
+	"github.com/Gitlawb/zero/internal/providercatalog"
+)
+
+func TestModelIDAllowedForProvider(t *testing.T) {
+	cases := []struct {
+		testName   string
+		providerID string
+		modelID    string
+		want       bool
+	}{
+		// Empty model ID is always rejected.
+		{"empty model", "any-provider", "", false},
+		{"empty model after trim", "any-provider", "  ", false},
+
+		// opencode-go-anthropic-compatible: only qwen and minimax allowed.
+		{"opencode-anthropic qwen", "opencode-go-anthropic-compatible", "qwen3.7-plus", true},
+		{"opencode-anthropic minimax", "opencode-go-anthropic-compatible", "MiniMax-M3", true},
+		{"opencode-anthropic non-allowed", "opencode-go-anthropic-compatible", "claude-sonnet-4.5", false},
+		{"opencode-anthropic deepseek", "opencode-go-anthropic-compatible", "deepseek-chat", false},
+
+		// Case insensitivity and trimming for the blocked provider.
+		{"opencode-anthropic case insensitive", "opencode-go-anthropic-compatible", "QWEN3.7-PLUS", true},
+		{"opencode-anthropic whitespace", "opencode-go-anthropic-compatible", "  minimax-m3  ", true},
+
+		// Normalized provider ID — e.g. NormalizeID converts spaces/dots to dashes.
+		{"opencode-anthropic normalized provider", "opencode go anthropic compatible", "qwen3.7-plus", true},
+
+		// Default branch: all model IDs allowed.
+		{"default provider allows anything", "openai", "claude-sonnet-4.5", true},
+		{"default provider allows any name", "openai", "x", true},
+		{"default provider groq", "groq", "deepseek-chat", true},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.testName, func(t *testing.T) {
+			got := ModelIDAllowedForProvider(tc.providerID, tc.modelID)
+			if got != tc.want {
+				t.Errorf("ModelIDAllowedForProvider(%q, %q) = %v, want %v",
+					tc.providerID, tc.modelID, got, tc.want)
+			}
+		})
+	}
+}
+
+// TestFilterModelsForProvider verifies that filtering delegates correctly.
+func TestFilterModelsForProvider(t *testing.T) {
+	models := []Model{
+		{ID: "qwen3.7-plus"},
+		{ID: "MiniMax-M3"},
+		{ID: "claude-sonnet-4.5"},
+		{ID: "deepseek-chat"},
+	}
+
+	filtered := FilterModelsForProvider("opencode-go-anthropic-compatible", models)
+	if len(filtered) != 2 {
+		t.Fatalf("FilterModelsForProvider returned %d models, want 2: %#v", len(filtered), modelIDs(filtered))
+	}
+	if filtered[0].ID != "qwen3.7-plus" || filtered[1].ID != "MiniMax-M3" {
+		t.Errorf("FilterModelsForProvider returned %#v, want [qwen3.7-plus MiniMax-M3]", modelIDs(filtered))
+	}
+
+	// With a default provider nothing is filtered out.
+	all := FilterModelsForProvider("openai", models)
+	if len(all) != len(models) {
+		t.Fatalf("FilterModelsForProvider(openai) returned %d, want %d", len(all), len(models))
+	}
+
+	// Empty input.
+	empty := FilterModelsForProvider("opencode-go-anthropic-compatible", nil)
+	if len(empty) != 0 {
+		t.Fatal("expected empty result for nil input")
+	}
+}
+
+// TestModelIDAllowedForProvider_NormalizedProviderIDs verifies that various
+// raw provider ID formats that NormalizeID maps to the same canonical form
+// are handled consistently.
+func TestModelIDAllowedForProvider_NormalizedProviderIDs(t *testing.T) {
+	canonical := providercatalog.NormalizeID("opencode-go-anthropic-compatible")
+	variants := []string{
+		"opencode-go-anthropic-compatible",
+		"opencode_go_anthropic_compatible",
+		"opencode go anthropic compatible",
+		"OpenCode-Go-Anthropic-Compatible",
+		"  opencode-go-anthropic-compatible  ",
+		"opencode.go.anthropic.compatible",
+	}
+	for _, variant := range variants {
+		if n := providercatalog.NormalizeID(variant); n != canonical {
+			t.Fatalf("NormalizeID(%q) = %q, want %q", variant, n, canonical)
+		}
+	}
+
+	// All variants should produce the same filter result.
+	for _, variant := range variants {
+		if !ModelIDAllowedForProvider(variant, "qwen3.7-plus") {
+			t.Errorf("ModelIDAllowedForProvider(%q, qwen3.7-plus) = false, want true", variant)
+		}
+		if ModelIDAllowedForProvider(variant, "claude-sonnet-4.5") {
+			t.Errorf("ModelIDAllowedForProvider(%q, claude-sonnet-4.5) = true, want false", variant)
+		}
+	}
+}

internal/providermodelcatalog/logic_test.go

@@ -11,7 +11,7 @@ import (
 )
 
 func TestLooksLikeCodingModelID(t *testing.T) {
-	coding := []string{"gpt-4o", "claude-sonnet-4.5", "o1", "o3-mini", "o4-mini", "qwen2.5-coder", "deepseek-chat", "kimi-k2", "codestral-latest", "grok-code"}
+	coding := []string{"gpt-4o", "claude-sonnet-4.5", "o1", "o3-mini", "o4-mini", "qwen2.5-coder", "deepseek-chat", "kimi-k2", "codestral-latest", "grok-code", "tencent/hy3"}
 	for _, id := range coding {
 		if !LooksLikeCodingModelID(id) {
 			t.Errorf("LooksLikeCodingModelID(%q) = false, want true", id)

internal/providermodelcatalog/remote_test.go

@@ -80,6 +80,14 @@ func TestParseOpenGatewayCatalogSupportsRichModelJSON(t *testing.T) {
 				"tags": ["coding", "free"],
 				"cost": {"input": 0, "output": 0}
 			},
+			{
+				"id": "tencent/hy3",
+				"name": "Tencent HY3",
+				"description": "free Tencent chat route",
+				"context_window": 262144,
+				"tools": true,
+				"tags": ["free"]
+			},
 			{
 				"id": "image-route",
 				"name": "Image Route",
@@ -92,8 +100,8 @@ func TestParseOpenGatewayCatalogSupportsRichModelJSON(t *testing.T) {
 	if err != nil {
 		t.Fatalf("ParseOpenGatewayCatalog returned error: %v", err)
 	}
-	if got := strings.Join(modelIDs(models), ","); got != "minimax-m3" {
-		t.Fatalf("models = %#v, want one gateway coding model", got)
+	if got := strings.Join(modelIDs(models), ","); got != "minimax-m3,tencent/hy3" {
+		t.Fatalf("models = %#v, want gateway coding models", got)
 	}
 	model := models[0]
 	if model.ID != "minimax-m3" || model.Description != "agentic coding route" {
@@ -108,6 +116,9 @@ func TestParseOpenGatewayCatalogSupportsRichModelJSON(t *testing.T) {
 	if model.Source != "opengateway" {
 		t.Fatalf("gateway source = %q, want opengateway", model.Source)
 	}
+	if models[1].ID != "tencent/hy3" || models[1].ContextWindow != 262144 || !models[1].ToolCall {
+		t.Fatalf("gateway HY3 model = %#v, want Tencent HY3 with context/tools", models[1])
+	}
 }
 
 func TestModelsDevProviderIDMapsZeroAliases(t *testing.T) {

internal/providermodelcatalog/stt_filter_test.go

@@ -0,0 +1,46 @@
+package providermodelcatalog
+
+import "testing"
+
+func TestIsSTTModelID(t *testing.T) {
+	in := []string{"whisper-1", "whisper-large-v3-turbo", "distil-whisper-large-v3-en",
+		"gpt-4o-transcribe", "gpt-4o-mini-transcribe", "nova-3-scribe", "parakeet-tdt-1.1b", "canary-1b"}
+	for _, id := range in {
+		if !IsSTTModelID(id) {
+			t.Errorf("%q should be an STT model by name", id)
+		}
+	}
+	out := []string{"gpt-4o", "claude-sonnet-4", "tts-1", "gpt-4o-mini-tts",
+		"dall-e-3", "text-to-speech-1", ""}
+	for _, id := range out {
+		if IsSTTModelID(id) {
+			t.Errorf("%q should NOT be an STT model by name", id)
+		}
+	}
+}
+
+func TestIsSTTModelUsesModalities(t *testing.T) {
+	// Audio in, text out → transcriber, even with an unfamiliar name.
+	if !IsSTTModel(Model{ID: "acme-speech-v2", InputModalities: []string{"audio"}, OutputModalities: []string{"text"}}) {
+		t.Error("audio-in/text-out model should be classified STT regardless of name")
+	}
+	// Audio out → TTS or speech-to-speech, never STT, even if the name says "transcribe".
+	if IsSTTModel(Model{ID: "weird-transcribe-tts", InputModalities: []string{"text"}, OutputModalities: []string{"audio"}}) {
+		t.Error("an audio-OUTPUT model must never be classified STT")
+	}
+	// Realtime speech-to-speech: audio in AND audio out → not a transcriber.
+	if IsSTTModel(Model{ID: "gpt-4o-realtime", InputModalities: []string{"audio", "text"}, OutputModalities: []string{"audio", "text"}}) {
+		t.Error("audio-in AND audio-out (speech-to-speech) must not be classified STT")
+	}
+	// Text-only LLM: input declared, no audio → not STT.
+	if IsSTTModel(Model{ID: "gpt-4o", InputModalities: []string{"text", "image"}, OutputModalities: []string{"text"}}) {
+		t.Error("a text/image-in model must not be classified STT")
+	}
+	// No modality metadata: fall back to the name heuristic.
+	if !IsSTTModel(Model{ID: "whisper-large-v3-turbo"}) {
+		t.Error("with no modalities, a whisper id should fall back to STT-true")
+	}
+	if IsSTTModel(Model{ID: "gpt-4o-mini-tts"}) {
+		t.Error("with no modalities, a tts id should be STT-false")
+	}
+}

internal/providermodeldiscovery/discovery.go

@@ -405,6 +405,9 @@ func mergeLiveModels(provider providercatalog.Descriptor, liveModels []Model, ca
 }
 
 func liveModelAllowedWithoutCatalog(provider providercatalog.Descriptor, id string) bool {
+	if !providermodelcatalog.ModelIDAllowedForProvider(provider.ID, id) {
+		return false
+	}
 	if providermodelcatalog.IsKnownNonCodingModelID(id) {
 		return false
 	}

internal/providermodeldiscovery/discovery_test.go

@@ -261,6 +261,47 @@ func TestDiscoverCatalogMergesLiveModelsWithModelsDevMetadata(t *testing.T) {
 	t.Fatal("missing gpt-4.1")
 }
 
+func TestLiveModelAllowedWithoutCatalogChecksProviderGateFirst(t *testing.T) {
+	// The ModelIDAllowedForProvider check runs before the others.
+	// For the restricted provider (opencode-go-anthropic-compatible) a
+	// non-allowed model returns false immediately, without reaching the
+	// IsKnownNonCodingModelID, Local, or LooksLikeCodingModelID checks.
+	restricted := providercatalog.Descriptor{
+		ID:    "opencode-go-anthropic-compatible",
+		Local: true, // would pass the Local check if we got past the gate
+	}
+
+	// A model that isn't qwen/minimax is blocked at the gate, even though
+	// Local=true would let any model through on its own.
+	if got := liveModelAllowedWithoutCatalog(restricted, "claude-sonnet-4"); got != false {
+		t.Fatal("liveModelAllowedWithoutCatalog: want false for claude-sonnet-4 on opencode-go-anthropic-compatible (blocked by ModelIDAllowedForProvider)")
+	}
+
+	// A qwen model passes the gate and continues to the remaining checks;
+	// it's not a known non-coding model and looks like a coding model, so
+	// the result is true.
+	if got := liveModelAllowedWithoutCatalog(restricted, "qwen-max"); got != true {
+		t.Fatal("liveModelAllowedWithoutCatalog: want true for qwen-max on opencode-go-anthropic-compatible (passes all checks)")
+	}
+
+	// A minimax model also passes the gate.
+	if got := liveModelAllowedWithoutCatalog(restricted, "minimax-text-01"); got != true {
+		t.Fatal("liveModelAllowedWithoutCatalog: want true for minimax-text-01 on opencode-go-anthropic-compatible (passes all checks)")
+	}
+
+	// Unrestricted provider: all models pass the gate, so the other checks
+	// decide the result. claude-sonnet-4 looks like a coding model → true.
+	openAI := providercatalog.Descriptor{ID: "openai"}
+	if got := liveModelAllowedWithoutCatalog(openAI, "claude-sonnet-4"); got != true {
+		t.Fatal("liveModelAllowedWithoutCatalog: want true for claude-sonnet-4 on openai (unrestricted)")
+	}
+
+	// Non-coding model still filtered on an unrestricted provider.
+	if got := liveModelAllowedWithoutCatalog(openAI, "text-embedding-3-large"); got != false {
+		t.Fatal("liveModelAllowedWithoutCatalog: want false for embedding model on openai")
+	}
+}
+
 func modelIDs(models []Model) []string {
 	ids := make([]string, 0, len(models))
 	for _, model := range models {

internal/providers/factory.go

@@ -10,6 +10,7 @@ import (
 	"github.com/Gitlawb/zero/internal/modelregistry"
 	"github.com/Gitlawb/zero/internal/oauth"
 	"github.com/Gitlawb/zero/internal/providercatalog"
+	"github.com/Gitlawb/zero/internal/providermodelcatalog"
 	"github.com/Gitlawb/zero/internal/providers/anthropic"
 	"github.com/Gitlawb/zero/internal/providers/gemini"
 	"github.com/Gitlawb/zero/internal/providers/openai"
@@ -205,6 +206,9 @@ func resolveProfile(profile config.ProviderProfile, options Options) (resolvedPr
 		} else if providerKind != modelProvider {
 			return resolvedProfile{}, fmt.Errorf("zero model %s belongs to %s, not %s", entry.ID, entry.Provider, providerKind)
 		}
+		if err := validateModelAllowedForProvider(profile, entry.ID); err != nil {
+			return resolvedProfile{}, err
+		}
 		return resolvedProfile{
 			providerKind:    providerKind,
 			apiModel:        entry.APIModel,
@@ -216,6 +220,9 @@ func resolveProfile(profile config.ProviderProfile, options Options) (resolvedPr
 	if providerKind == "" {
 		providerKind = config.ProviderKindOpenAI
 	}
+	if err := validateModelAllowedForProvider(profile, model); err != nil {
+		return resolvedProfile{}, err
+	}
 	return resolvedProfile{
 		providerKind: providerKind,
 		apiModel:     model,
@@ -223,6 +230,29 @@ func resolveProfile(profile config.ProviderProfile, options Options) (resolvedPr
 	}, nil
 }
 
+// validateModelAllowedForProvider enforces provider-scoped model allowlists at
+// runtime resolution time. It delegates to
+// providermodelcatalog.ModelIDAllowedForProvider, which encodes the per-provider
+// rules in one place; restricted providers (such as
+// opencode-go-anthropic-compatible) only accept a curated subset of model
+// families, while the default branch makes unrestricted providers a no-op. This
+// guards both New() (TUI /model, headless --model overrides) and
+// ResolveRuntimeMetadata (the read-only metadata path) so a catalog-backed
+// profile cannot persist or send a model outside its scoped allowlist.
+func validateModelAllowedForProvider(profile config.ProviderProfile, model string) error {
+	providerID := strings.TrimSpace(profile.CatalogID)
+	if providermodelcatalog.ModelIDAllowedForProvider(providerID, model) {
+		return nil
+	}
+	if providerID == "" {
+		providerID = strings.TrimSpace(profile.Name)
+	}
+	if providerID == "" {
+		providerID = "provider"
+	}
+	return fmt.Errorf("provider %s does not allow model %s", providerID, strings.TrimSpace(model))
+}
+
 func explicitProviderKind(profile config.ProviderProfile) (config.ProviderKind, bool) {
 	providerKind := config.ProviderKind(strings.TrimSpace(strings.ToLower(string(profile.ProviderKind))))
 	if providerKind != "" {

internal/providers/factory_test.go

@@ -56,6 +56,56 @@ func TestNewCreatesOpenAIProviderWithFactoryOptions(t *testing.T) {
 	}
 }
 
+func TestNewPassesOpenGatewayHY3ModelThrough(t *testing.T) {
+	transport := &captureTransport{
+		responseBody: "data: [DONE]\n\n",
+	}
+	client := &http.Client{Transport: transport}
+
+	provider, err := New(config.ProviderProfile{
+		Name:         "opengateway",
+		CatalogID:    "gitlawb-opengateway",
+		ProviderKind: config.ProviderKindOpenAICompatible,
+		APIKey:       "ogw_live_test",
+		Model:        "tencent/hy3",
+	}, Options{HTTPClient: client})
+	if err != nil {
+		t.Fatalf("New() error = %v", err)
+	}
+	stream, err := provider.StreamCompletion(context.Background(), zeroruntime.CompletionRequest{
+		Messages: []zeroruntime.Message{{Role: zeroruntime.MessageRoleUser, Content: "hello"}},
+	})
+	if err != nil {
+		t.Fatalf("StreamCompletion() error = %v", err)
+	}
+	for range stream {
+	}
+
+	if transport.request.URL.String() != "https://opengateway.gitlawb.com/v1/chat/completions" {
+		t.Fatalf("request URL = %q, want OpenGateway chat completions", transport.request.URL.String())
+	}
+	var body map[string]any
+	if err := json.NewDecoder(transport.body()).Decode(&body); err != nil {
+		t.Fatalf("decode request body: %v", err)
+	}
+	if body["model"] != "tencent/hy3" {
+		t.Fatalf("model = %q, want tencent/hy3 passthrough", body["model"])
+	}
+
+	metadata, err := ResolveRuntimeMetadata(config.ProviderProfile{
+		Name:         "opengateway",
+		CatalogID:    "gitlawb-opengateway",
+		ProviderKind: config.ProviderKindOpenAICompatible,
+		Model:        "tencent/hy3",
+	}, Options{})
+	if err != nil {
+		t.Fatalf("ResolveRuntimeMetadata() error = %v", err)
+	}
+	if metadata.ProviderKind != config.ProviderKindOpenAICompatible || metadata.APIModel != "tencent/hy3" {
+		t.Fatalf("runtime metadata = %#v, want OpenAI-compatible tencent/hy3", metadata)
+	}
+}
+
 func TestNewThreadsCustomProviderHeaders(t *testing.T) {
 	transport := &captureTransport{
 		responseBody: "data: [DONE]\n\n",
@@ -466,3 +516,101 @@ func TestCodexAccountForKey(t *testing.T) {
 		t.Fatalf("account = %q, want acc-rotated (in-place refresh must be picked up)", got)
 	}
 }
+
+// TestNewRejectsModelOutsideProviderAllowlist guards the PR #544 P2 fix:
+// opencode-go-anthropic-compatible only accepts Qwen and MiniMax model IDs,
+// so a Claude model routed through this catalog-backed profile must be rejected
+// at runtime, not silently forwarded to https://opencode.ai/zen/go/v1/messages.
+func TestNewRejectsModelOutsideProviderAllowlist(t *testing.T) {
+	_, err := New(config.ProviderProfile{
+		Name:      "opencode-go-anthropic",
+		CatalogID: "opencode-go-anthropic-compatible",
+		APIKey:    "sk-test",
+		Model:     "claude-sonnet-4.5",
+	}, Options{})
+	if err == nil {
+		t.Fatal("New() error = nil, want claude-sonnet-4.5 rejected for opencode-go-anthropic-compatible")
+	}
+	if !strings.Contains(err.Error(), "opencode-go-anthropic-compatible") {
+		t.Fatalf("error = %q, want it to name the provider", err.Error())
+	}
+	if !strings.Contains(err.Error(), "claude-sonnet-4.5") {
+		t.Fatalf("error = %q, want it to name the rejected model", err.Error())
+	}
+}
+
+// TestNewRejectsRawModelOutsideProviderAllowlist covers the registry-miss
+// branch of resolveProfile: an unknown raw model id (not in the model registry)
+// typed by the user into a restricted-provider profile must still be rejected
+// rather than passthrough-sent.
+func TestNewRejectsRawModelOutsideProviderAllowlist(t *testing.T) {
+	_, err := New(config.ProviderProfile{
+		Name:      "opencode-go-anthropic",
+		CatalogID: "opencode-go-anthropic-compatible",
+		APIKey:    "sk-test",
+		Model:     "totally-custom-not-in-allowlist-12345",
+	}, Options{})
+	if err == nil {
+		t.Fatal("New() error = nil, want unknown raw model rejected for opencode-go-anthropic-compatible")
+	}
+	if !strings.Contains(err.Error(), "does not allow model") {
+		t.Fatalf("error = %q, want allowlist rejection", err.Error())
+	}
+	if !strings.Contains(err.Error(), "totally-custom-not-in-allowlist-12345") {
+		t.Fatalf("error = %q, want the raw model name to appear in the error", err.Error())
+	}
+}
+
+// TestNewAllowsCuratedModelsForRestrictedProvider proves the gate is not
+// over-eager: Qwen and MiniMax curated models pass through unchanged for
+// opencode-go-anthropic-compatible.
+func TestNewAllowsCuratedModelsForRestrictedProvider(t *testing.T) {
+	for _, model := range []string{"minimax-m3", "qwen3.7-plus", "qwen3.7-max", "minimax-m2.7"} {
+		_, err := New(config.ProviderProfile{
+			Name:      "opencode-go-anthropic",
+			CatalogID: "opencode-go-anthropic-compatible",
+			APIKey:    "sk-test",
+			Model:     model,
+		}, Options{})
+		if err != nil {
+			t.Fatalf("New() error = %v, want curated model %q to be allowed", err, model)
+		}
+	}
+}
+
+// TestNewAllowsAnyModelForUnrestrictedProvider is the regression guard:
+// unrestricted providers (no catalog or default catalog id) must continue to
+// accept any model id, including those outside the opencode allowlist.
+func TestNewAllowsAnyModelForUnrestrictedProvider(t *testing.T) {
+	_, err := New(config.ProviderProfile{
+		Name:         "anthropic",
+		ProviderKind: config.ProviderKindAnthropic,
+		APIKey:       "sk-ant",
+		Model:        "claude-sonnet-4.5",
+	}, Options{})
+	if err != nil {
+		t.Fatalf("New() error = %v, want unrestricted anthropic provider to accept claude-sonnet-4.5", err)
+	}
+}
+
+// TestResolveRuntimeMetadataRejectsModelOutsideProviderAllowlist guards the
+// read-only metadata path (called from TUI command_center, exec, provider
+// health, context report). The metadata path must enforce the same gate as
+// New() so a config-time override cannot escape through it.
+func TestResolveRuntimeMetadataRejectsModelOutsideProviderAllowlist(t *testing.T) {
+	_, err := ResolveRuntimeMetadata(config.ProviderProfile{
+		Name:      "opencode-go-anthropic",
+		CatalogID: "opencode-go-anthropic-compatible",
+		APIKey:    "sk-test",
+		Model:     "claude-sonnet-4.5",
+	}, Options{})
+	if err == nil {
+		t.Fatal("ResolveRuntimeMetadata error = nil, want claude-sonnet-4.5 rejected")
+	}
+	if !strings.Contains(err.Error(), "opencode-go-anthropic-compatible") {
+		t.Fatalf("error = %q, want it to name the provider", err.Error())
+	}
+	if !strings.Contains(err.Error(), "claude-sonnet-4.5") {
+		t.Fatalf("error = %q, want it to name the rejected model", err.Error())
+	}
+}

internal/sandbox/grant_scope.go

@@ -200,20 +200,23 @@ func normalizeHostScope(raw string) string {
 // directory itself or any descendant; a host grant matches its exact normalized
 // host. A narrower grant never covers a tool-wide request (reqScope == ""), so
 // such a request re-prompts (fail-safe).
+//
+// File and dir comparisons go through filepath.Rel (via scopePathEqual and the
+// shared pathWithinRoot helper) rather than a plain string comparison, so they
+// apply the same case-folding as the workspace-boundary check on Windows --
+// otherwise a persisted grant (including a deny) could be silently bypassed by
+// spelling the same path with different case.
 func grantCovers(grant Grant, reqScope string) bool {
 	switch grant.ScopeKind {
 	case ScopeToolWide:
 		return true
 	case ScopeFile:
-		return reqScope != "" && reqScope == grant.Scope
+		return reqScope != "" && scopePathEqual(grant.Scope, reqScope)
 	case ScopeDir:
 		if reqScope == "" || grant.Scope == "" {
 			return false
 		}
-		if reqScope == grant.Scope {
-			return true
-		}
-		return strings.HasPrefix(reqScope, grant.Scope+string(filepath.Separator))
+		return pathWithinRoot(grant.Scope, reqScope)
 	case ScopeHost:
 		return reqScope != "" && normalizeHostScope(reqScope) == normalizeHostScope(grant.Scope)
 	default:
@@ -221,6 +224,14 @@ func grantCovers(grant Grant, reqScope string) bool {
 	}
 }
 
+// scopePathEqual reports whether two absolute, cleaned scope paths refer to
+// the same file, applying the same case-folding filepath.Rel already uses for
+// directory-boundary checks (case-insensitive path components on Windows).
+func scopePathEqual(a, b string) bool {
+	rel, err := filepath.Rel(a, b)
+	return err == nil && rel == "."
+}
+
 // scopeSpecificity ranks scope kinds so the most precise covering allow wins when
 // several grants match the same request.
 func scopeSpecificity(kind ScopeKind) int {

internal/sandbox/grant_scope_test.go

@@ -2,6 +2,8 @@ package sandbox
 
 import (
 	"path/filepath"
+	"runtime"
+	"strings"
 	"testing"
 )
 
@@ -234,3 +236,25 @@ func TestGrantCovers(t *testing.T) {
 		})
 	}
 }
+
+// TestGrantCoversCaseInsensitiveOnWindows guards against a persisted grant
+// (including a deny) being silently bypassed by spelling the same path with
+// different case, since Windows path components are case-insensitive.
+func TestGrantCoversCaseInsensitiveOnWindows(t *testing.T) {
+	if runtime.GOOS != "windows" {
+		t.Skip("path case-insensitivity is a Windows-specific filesystem property")
+	}
+	dir := filepath.Join(string(filepath.Separator)+"proj", "src")
+	file := filepath.Join(dir, "main.go")
+	descendant := filepath.Join(dir, "api", "z.go")
+
+	fileGrant := Grant{Scope: file, ScopeKind: ScopeFile}
+	dirGrant := Grant{Scope: dir, ScopeKind: ScopeDir}
+
+	if !grantCovers(fileGrant, strings.ToUpper(file)) {
+		t.Fatalf("file grant %q should cover differently-cased request %q on Windows", file, strings.ToUpper(file))
+	}
+	if !grantCovers(dirGrant, strings.ToUpper(descendant)) {
+		t.Fatalf("dir grant %q should cover differently-cased descendant %q on Windows", dir, strings.ToUpper(descendant))
+	}
+}

internal/sandbox/safe_command.go

@@ -26,6 +26,10 @@ type interactiveProgram struct {
 	suggestion string
 	// windowsOnly limits the match to GOOS == "windows" (e.g. notepad).
 	windowsOnly bool
+	// windowsSuggestion overrides suggestion on GOOS == "windows", for cases
+	// where the default suggestion names POSIX-only tools (cat/head/tail)
+	// that cmd.exe does not have.
+	windowsSuggestion string
 }
 
 // interactivePrograms maps a bare command name to its non-interactive guidance.
@@ -39,9 +43,21 @@ var interactivePrograms = map[string]interactiveProgram{
 	"emacs": {reason: "emacs opens an interactive session", suggestion: "Use `emacs --batch` for scripting, or the edit_file/write_file tools."},
 	"pico":  {reason: "pico is a full-screen editor that waits for keystrokes", suggestion: "Use the edit_file/write_file tools or `sed -i`."},
 	// Pagers.
-	"less": {reason: "less is a pager that waits for navigation keys", suggestion: "Use `cat`, `head`, or `tail -n N` to print file contents non-interactively."},
-	"more": {reason: "more is a pager that waits for navigation keys", suggestion: "Use `cat`, `head`, or `tail -n N` to print file contents non-interactively."},
-	"most": {reason: "most is a pager that waits for navigation keys", suggestion: "Use `cat`, `head`, or `tail -n N` to print file contents non-interactively."},
+	"less": {
+		reason:            "less is a pager that waits for navigation keys",
+		suggestion:        "Use `cat`, `head`, or `tail -n N` to print file contents non-interactively.",
+		windowsSuggestion: "Use `type` to print file contents non-interactively, or the read_file tool with offset/limit for a partial view.",
+	},
+	"more": {
+		reason:            "more is a pager that waits for navigation keys",
+		suggestion:        "Use `cat`, `head`, or `tail -n N` to print file contents non-interactively.",
+		windowsSuggestion: "Use `type` to print file contents non-interactively, or the read_file tool with offset/limit for a partial view.",
+	},
+	"most": {
+		reason:            "most is a pager that waits for navigation keys",
+		suggestion:        "Use `cat`, `head`, or `tail -n N` to print file contents non-interactively.",
+		windowsSuggestion: "Use `type` to print file contents non-interactively, or the read_file tool with offset/limit for a partial view.",
+	},
 	// Process/system monitors.
 	"top":   {reason: "top runs a live full-screen dashboard until you quit it", suggestion: "Use `ps aux` (optionally `| head`) for a one-shot snapshot."},
 	"htop":  {reason: "htop runs a live full-screen dashboard until you quit it", suggestion: "Use `ps aux` (optionally `| head`) for a one-shot snapshot."},
@@ -186,11 +202,15 @@ func DetectInteractiveCommand(command string, goos string) InteractiveCommandRes
 		if hasNonInteractiveFlag(first, fields) {
 			continue
 		}
+		suggestion := program.suggestion
+		if goos == "windows" && program.windowsSuggestion != "" {
+			suggestion = program.windowsSuggestion
+		}
 		return InteractiveCommandResult{
 			Interactive: true,
 			Command:     first,
 			Reason:      program.reason,
-			Suggestion:  program.suggestion,
+			Suggestion:  suggestion,
 		}
 	}
 

internal/sandbox/safe_command_test.go

@@ -88,6 +88,28 @@ func TestDetectInteractiveCommandHonorsWindows(t *testing.T) {
 	}
 }
 
+// TestDetectInteractiveCommandPagerSuggestionIsPlatformSpecific covers a fix
+// for suggesting POSIX-only tools (cat/head/tail) as the escape hatch for a
+// blocked pager on Windows, where cmd.exe has none of them.
+func TestDetectInteractiveCommandPagerSuggestionIsPlatformSpecific(t *testing.T) {
+	for _, pager := range []string{"less", "more", "most"} {
+		linux := DetectInteractiveCommand(pager+" notes.txt", "linux")
+		if !linux.Interactive || !strings.Contains(linux.Suggestion, "cat") {
+			t.Fatalf("%s on linux: expected cat/head/tail suggestion, got %+v", pager, linux)
+		}
+		windows := DetectInteractiveCommand(pager+" notes.txt", "windows")
+		if !windows.Interactive {
+			t.Fatalf("%s on windows: expected interactive block, got %+v", pager, windows)
+		}
+		if strings.Contains(windows.Suggestion, "cat") || strings.Contains(windows.Suggestion, "tail") {
+			t.Fatalf("%s on windows: suggestion should not name POSIX-only tools, got %q", pager, windows.Suggestion)
+		}
+		if !strings.Contains(windows.Suggestion, "type") {
+			t.Fatalf("%s on windows: expected type suggestion, got %q", pager, windows.Suggestion)
+		}
+	}
+}
+
 func TestDetectInteractiveCommandFindsAcrossSeparators(t *testing.T) {
 	// Interactive commands hidden after a shell operator should still be caught.
 	for _, command := range []string{

internal/securefile/securefile.go

@@ -26,6 +26,8 @@ const (
 	secretRetryDelay    = 2 * time.Millisecond
 )
 
+var openSecretLockFile = os.OpenFile
+
 // Crypter encrypts a blob at rest with AES-256-GCM under a per-user random secret
 // persisted (0600) at secretPath.
 type Crypter struct {
@@ -107,7 +109,7 @@ func createSecretFile(path string) ([]byte, error) {
 	lockPath := path + ".lock"
 	var lastErr error
 	for attempt := 0; attempt < secretRetryAttempts; attempt++ {
-		lock, err := os.OpenFile(lockPath, os.O_CREATE|os.O_EXCL|os.O_WRONLY, 0o600)
+		lock, err := openSecretLockFile(lockPath, os.O_CREATE|os.O_EXCL|os.O_WRONLY, 0o600)
 		if err == nil {
 			_ = lock.Close()
 			defer os.Remove(lockPath)
@@ -118,20 +120,25 @@ func createSecretFile(path string) ([]byte, error) {
 			}
 			return writeNewSecretFile(path)
 		}
-		if !errors.Is(err, os.ErrExist) {
+		// On Windows a concurrent holder's os.Remove leaves the lock file in a
+		// "delete pending" state, so an O_EXCL create races it with
+		// ERROR_ACCESS_DENIED (os.ErrPermission) rather than ErrExist. Treat that
+		// as contention and retry too -- mirroring oauth's createSecretFile --
+		// otherwise concurrent secret creation spuriously fails on Windows.
+		if !errors.Is(err, os.ErrExist) && !errors.Is(err, os.ErrPermission) {
 			return nil, fmt.Errorf("securefile: create secret lock: %w", err)
 		}
+		// Remember the lock-creation error itself rather than a subsequent
+		// "secret file doesn't exist yet" read error -- otherwise a real
+		// contention/ACL problem is masked by the expected-while-waiting
+		// ErrNotExist once the retries are exhausted.
+		lastErr = err
 		if data, rerr := readSecretFileRetry(path); rerr == nil {
 			return data, nil
-		} else {
-			lastErr = rerr
 		}
 		time.Sleep(secretRetryDelay)
 	}
-	if lastErr != nil {
-		return nil, fmt.Errorf("securefile: timed out waiting for secret %s: %w", path, lastErr)
-	}
-	return nil, fmt.Errorf("securefile: timed out waiting for secret lock %s", lockPath)
+	return nil, fmt.Errorf("securefile: timed out waiting for secret %s: %w", path, lastErr)
 }
 
 func writeNewSecretFile(path string) ([]byte, error) {

internal/securefile/securefile_test.go

@@ -7,6 +7,33 @@ import (
 	"testing"
 )
 
+func TestCreateSecretFileRetriesOnPermissionContention(t *testing.T) {
+	secretPath := filepath.Join(t.TempDir(), "k.secret")
+	attempts := 0
+	origOpen := openSecretLockFile
+	openSecretLockFile = func(path string, flag int, perm os.FileMode) (*os.File, error) {
+		attempts++
+		if attempts == 1 {
+			return nil, os.ErrPermission
+		}
+		return os.OpenFile(path, flag, perm)
+	}
+	t.Cleanup(func() {
+		openSecretLockFile = origOpen
+	})
+
+	secret, err := createSecretFile(secretPath)
+	if err != nil {
+		t.Fatalf("createSecretFile should retry on permission contention: %v", err)
+	}
+	if len(secret) != secretBytes {
+		t.Fatalf("secret length = %d, want %d", len(secret), secretBytes)
+	}
+	if attempts < 2 {
+		t.Fatalf("expected at least 2 lock attempts, got %d", attempts)
+	}
+}
+
 func TestSealOpenRoundTrip(t *testing.T) {
 	secret := filepath.Join(t.TempDir(), "k.secret")
 	c := NewCrypter(secret)

internal/sessions/exec_session.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"log"
 	"strings"
+	"unicode/utf8"
 )
 
 type ExecMode string
@@ -221,11 +222,24 @@ func summarizePayload(payload any) string {
 		text = string(data)
 	}
 	if len(text) > 500 {
-		return text[:500]
+		return truncateUTF8(text, 500)
 	}
 	return text
 }
 
+// truncateUTF8 returns the longest prefix of s that is at most n bytes,
+// backing off to the nearest rune boundary so a multi-byte character isn't
+// split — a split rune here would embed invalid UTF-8 into the exec prompt.
+func truncateUTF8(s string, n int) string {
+	if len(s) <= n {
+		return s
+	}
+	for n > 0 && !utf8.RuneStart(s[n]) {
+		n--
+	}
+	return s[:n]
+}
+
 func extractText(value any) string {
 	switch typed := value.(type) {
 	case string:

internal/sessions/store_test.go

@@ -11,6 +11,7 @@ import (
 	"sync"
 	"testing"
 	"time"
+	"unicode/utf8"
 )
 
 func TestStoreCreatesAppendsListsAndReadsEvents(t *testing.T) {
@@ -640,6 +641,23 @@ func TestFormatExecPromptTruncatesConversationMessagesAfterFilteringNoise(t *tes
 	}
 }
 
+// A truncation cut at a raw byte offset can land in the middle of a
+// multi-byte UTF-8 rune (e.g. CJK text), embedding invalid UTF-8 into the
+// exec prompt. summarizePayload must back off to a rune boundary instead.
+func TestSummarizePayloadTruncatesOnRuneBoundary(t *testing.T) {
+	content := strings.Repeat("中文", 300) // 900 bytes of 3-byte runes
+	payload := json.RawMessage(fmt.Sprintf(`{"role":"user","content":%q}`, content))
+
+	got := summarizePayload(payload)
+
+	if !utf8.ValidString(got) {
+		t.Fatalf("summarizePayload produced invalid UTF-8: %q", got)
+	}
+	if len(got) > 500 {
+		t.Fatalf("expected summary to be at most 500 bytes, got %d", len(got))
+	}
+}
+
 func TestPrepareExecPersistsSpecialistMetadataForNewSession(t *testing.T) {
 	store := NewStore(StoreOptions{RootDir: t.TempDir(), Now: fixedClock("2026-06-04T14:30:00Z")})
 

internal/skills/skills.go

@@ -77,9 +77,9 @@ type DuplicateName struct {
 // winner regardless of sort stability. Use Duplicates to surface a warning about
 // any such collisions.
 //
-// NOTE: Load currently scans a single root (ZERO_SKILLS_DIR / the data dir).
-// Plugin-declared skill paths (the plugins manifest "skills" array) are NOT yet
-// merged into this lookup; multi-root loading is tracked as a separate feature.
+// NOTE: Load scans one root. Agent startup merges plugin-declared skill roots
+// separately during plugin activation, so the runtime skill surface can include
+// both the default directory and skills bundled by active plugins.
 func Load(dir string) ([]Skill, error) {
 	skills, _, err := load(dir)
 	return skills, err

internal/tools/bash_tool_test.go

@@ -152,7 +152,7 @@ func TestDetectShellCommandIssueAllowsWindowsCDSwitch(t *testing.T) {
 	}
 }
 
-func TestDetectShellCommandIssueRequiresActualLSCommand(t *testing.T) {
+func TestDetectShellCommandIssueFlagsWindowsBadCommands(t *testing.T) {
 	for _, command := range []string{
 		`echo false ls -la`,
 		`echo list -items`,
@@ -172,6 +172,22 @@ func TestDetectShellCommandIssueRequiresActualLSCommand(t *testing.T) {
 			t.Fatalf("expected actual ls command to be flagged for %q", command)
 		}
 	}
+
+	// Common Unix filters used for truncation (e.g. gh output) must be caught.
+	for _, command := range []string{
+		`gh pr view 465 | head -200`,
+		`some-cmd | tail -n 10`,
+		`cat file | head -5`,
+		`ps aux | head`,
+		// Issue #467's exact reported case: `| cat` alone (no other POSIX
+		// utility in the pipeline) must also be flagged before execution.
+		`gh pr view 465 --json reviews,comments -q '.reviews | length' 2>&1 | cat`,
+		`some-cmd | cat`,
+	} {
+		if issue := detectShellCommandIssue(command, "windows"); issue == nil {
+			t.Fatalf("expected POSIX filter command to be flagged for %q", command)
+		}
+	}
 }
 
 func TestDetectShellCommandIssueFlagsPipedPosixUtilities(t *testing.T) {
@@ -191,6 +207,55 @@ func TestDetectShellCommandIssueFlagsPipedPosixUtilities(t *testing.T) {
 	}
 }
 
+func TestDetectShellCommandIssueIgnoresQuotedPipeText(t *testing.T) {
+	for _, command := range []string{
+		`gh pr comment --body "please do not use | cat here"`,
+		`git commit -m "grep for TODO later"`,
+		`git commit -m "fix | cat pipe"`,
+	} {
+		if issue := detectShellCommandIssue(command, "windows"); issue != nil {
+			t.Fatalf("expected POSIX-utility text inside a quoted argument to pass for %q, got %#v", command, issue)
+		}
+	}
+
+	// The same utility names, actually piped (unquoted), must still be flagged.
+	for _, command := range []string{
+		`echo test | cat`,
+		`echo test | grep TODO`,
+	} {
+		if issue := detectShellCommandIssue(command, "windows"); issue == nil {
+			t.Fatalf("expected unquoted POSIX utility pipeline to still be flagged for %q", command)
+		}
+	}
+}
+
+func TestDetectShellCommandIssueIgnoresCaretEscapedMetachars(t *testing.T) {
+	for _, command := range []string{
+		`foo^|cat`,
+		`echo a^&cat`,
+		`echo a^;cat`,
+	} {
+		if issue := detectShellCommandIssue(command, "windows"); issue != nil {
+			t.Fatalf("expected caret-escaped metachar to read as a literal for %q, got %#v", command, issue)
+		}
+	}
+
+	// The same shape, unescaped, must still be flagged.
+	if issue := detectShellCommandIssue(`foo|cat`, "windows"); issue == nil {
+		t.Fatal("expected unescaped pipe into cat to still be flagged")
+	}
+}
+
+func TestDetectShellCommandIssueSuggestionOmitsBlockedMore(t *testing.T) {
+	issue := detectShellCommandIssue(`some_command | wc -l`, "windows")
+	if issue == nil {
+		t.Fatal("expected POSIX utility pipeline to be flagged")
+	}
+	if strings.Contains(issue.Suggestion, "more") {
+		t.Fatalf("suggestion should not recommend more, which is itself blocked as an interactive pager on Windows: %q", issue.Suggestion)
+	}
+}
+
 func TestDetectShellCommandIssueAllowsUnrelatedCommands(t *testing.T) {
 	for _, command := range []string{
 		`git log --oneline`,
@@ -207,6 +272,31 @@ func TestDetectShellCommandIssueAllowsUnrelatedCommands(t *testing.T) {
 	}
 }
 
+// Operator/utility-name text that only appears inside a quoted argument must
+// not be mistaken for real shell syntax — e.g. `echo "foo; ls -la"` is a
+// harmless echo, not a bash-style `ls` invocation, and quoted `head`/`grep`
+// text isn't a piped POSIX utility.
+func TestDetectShellCommandIssueIgnoresQuotedContent(t *testing.T) {
+	for _, command := range []string{
+		`echo "foo; ls -la"`,
+		`echo "run head over the file"`,
+		`echo 'ls -la is a common bash command'`,
+		`echo "grep for the pattern"`,
+	} {
+		if issue := detectShellCommandIssue(command, "windows"); issue != nil {
+			t.Fatalf("expected quoted content to be ignored for %q, got %#v", command, issue)
+		}
+	}
+
+	// Sanity: the same utility names still get flagged when they're NOT quoted.
+	// cmd.exe (unlike bash) does not treat ; as a statement separator, so
+	// `echo "foo" ; ls -la` is a single echo invocation with literal
+	// arguments, not a real ls invocation, and must not be flagged.
+	if issue := detectShellCommandIssue(`git log | head`, "windows"); issue == nil {
+		t.Fatalf("expected unquoted shell syntax to still be flagged for %q", `git log | head`)
+	}
+}
+
 func TestDetectShellOutputIssueAddsWindowsSyntaxHint(t *testing.T) {
 	issue := detectShellOutputIssue("The syntax of the command is incorrect.", "windows")
 	if issue == nil {
@@ -668,8 +758,15 @@ func TestBashToolBlocksInteractiveCommandThroughSandbox(t *testing.T) {
 	if result.Status != StatusError {
 		t.Fatalf("expected error status, got %s: %s", result.Status, result.Output)
 	}
-	if !strings.Contains(result.Output, "interactive") || !strings.Contains(result.Output, "cat") {
-		t.Fatalf("expected pager guard message with cat suggestion, got %q", result.Output)
+	// The suggested non-interactive alternative is platform-specific: cat
+	// doesn't exist on Windows cmd.exe, so the guard suggests `type` there
+	// instead (see safe_command.go's windowsSuggestion).
+	wantSuggestion := "cat"
+	if runtime.GOOS == "windows" {
+		wantSuggestion = "type"
+	}
+	if !strings.Contains(result.Output, "interactive") || !strings.Contains(result.Output, wantSuggestion) {
+		t.Fatalf("expected pager guard message with %q suggestion, got %q", wantSuggestion, result.Output)
 	}
 }
 

internal/tools/file_tools_test.go

@@ -76,6 +76,45 @@ func TestReadFileToolAppliesByteBudget(t *testing.T) {
 	}
 }
 
+func TestReadFileToolTracksWholeFileHashWhenReadingSmallRange(t *testing.T) {
+	root := t.TempDir()
+	var builder strings.Builder
+	for i := 1; i <= 2000; i++ {
+		builder.WriteString("line ")
+		builder.WriteString(strings.Repeat("x", 16))
+		builder.WriteString("\n")
+	}
+	content := builder.String()
+	path := filepath.Join(root, "large.txt")
+	writeTestFile(t, path, content)
+
+	tracker := NewFileTracker()
+	tool := NewReadFileTool(root).(optionsAwareTool)
+	result := tool.RunWithOptions(context.Background(), map[string]any{
+		"path":       "large.txt",
+		"start_line": 1000,
+		"max_lines":  2,
+	}, RunOptions{FileTracker: tracker})
+
+	if result.Status != StatusOK {
+		t.Fatalf("expected ok status, got %s: %s", result.Status, result.Output)
+	}
+	resolved, err := filepath.EvalSymlinks(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	version, ok := tracker.Version(resolved)
+	if !ok {
+		t.Fatal("expected read_file to record a file version")
+	}
+	if version.Hash != HashContent([]byte(content)) {
+		t.Fatalf("hash = %q, want %q", version.Hash, HashContent([]byte(content)))
+	}
+	if err := tracker.CheckConflict(resolved, []byte(content+"changed")); err != ErrFileChangedOnDisk {
+		t.Fatalf("changed content should conflict, got %v", err)
+	}
+}
+
 func TestReadFileToolRejectsOutsideWorkspace(t *testing.T) {
 	root := t.TempDir()
 	outside := filepath.Join(t.TempDir(), "secret.txt")
@@ -205,6 +244,33 @@ func TestGrepToolMakesHeadLimitTruncationVisible(t *testing.T) {
 	}
 }
 
+func TestGrepToolCountsAllLinesWhileKeepingHeadLimitSmall(t *testing.T) {
+	root := t.TempDir()
+	var builder strings.Builder
+	for i := 0; i < 100; i++ {
+		builder.WriteString("needle ")
+		builder.WriteString(strings.Repeat("x", 8))
+		builder.WriteString("\n")
+	}
+	writeTestFile(t, filepath.Join(root, "notes.txt"), builder.String())
+
+	result := NewGrepTool(root).Run(context.Background(), map[string]any{
+		"pattern":    "needle",
+		"path":       ".",
+		"head_limit": 3,
+	})
+
+	if result.Status != StatusOK || !result.Truncated {
+		t.Fatalf("expected ok+truncated, got status=%s truncated=%v output=%q", result.Status, result.Truncated, result.Output)
+	}
+	if !strings.Contains(result.Output, "[truncated: showing first 3 of 100 matches") {
+		t.Fatalf("expected exact total match count, got %q", result.Output)
+	}
+	if strings.Contains(result.Output, "notes.txt:4:") {
+		t.Fatalf("head_limit leaked fourth result: %q", result.Output)
+	}
+}
+
 // A glob is matched relative to the search directory, not the workspace root, so
 // `path=subdir glob=*.go` finds subdir/a.go (as "a.go"). Previously the glob was
 // matched against the workspace-relative "subdir/a.go", so a non-recursive "*.go"
@@ -255,6 +321,22 @@ func TestGrepToolSupportsFilesAndCountModes(t *testing.T) {
 	}
 }
 
+func TestGrepCountModeCountsMultipleHitsPerLine(t *testing.T) {
+	root := t.TempDir()
+	writeTestFile(t, filepath.Join(root, "notes.txt"), "needle needle\nneedle\n")
+
+	count := NewGrepTool(root).Run(context.Background(), map[string]any{
+		"pattern":     "needle",
+		"output_mode": "count",
+	})
+	if count.Status != StatusOK {
+		t.Fatalf("expected count result, got %s: %s", count.Status, count.Output)
+	}
+	if count.Output != "3 matches found" {
+		t.Fatalf("expected count output, got %q", count.Output)
+	}
+}
+
 // Finding 1: grep must not follow an in-workspace symlink that points to a file
 // OUTSIDE the workspace (confinement bypass). The symlinked secret must not be
 // searched or returned, mirroring read_file's EvalSymlinks confinement.

internal/tools/file_tracker.go

@@ -42,10 +42,16 @@ func NewFileTracker() *FileTracker {
 
 // Record stores the version of absPath given its content and optional stat info.
 func (tracker *FileTracker) Record(absPath string, content []byte, info os.FileInfo) {
+	tracker.RecordHash(absPath, HashContent(content), info)
+}
+
+// RecordHash stores the version of absPath when the caller already computed
+// the same HashContent-compatible SHA-256 while reading the file.
+func (tracker *FileTracker) RecordHash(absPath string, hash string, info os.FileInfo) {
 	if tracker == nil {
 		return
 	}
-	version := FileVersion{Hash: HashContent(content)}
+	version := FileVersion{Hash: hash}
 	if info != nil {
 		version.Size = info.Size()
 		version.MTime = info.ModTime()

internal/tools/file_tracker_test.go

@@ -34,6 +34,18 @@ func TestFileTrackerRecordsAndReadsBackVersion(t *testing.T) {
 	}
 }
 
+func TestFileTrackerRecordHashMatchesRecord(t *testing.T) {
+	tracker := NewFileTracker()
+	content := []byte("streamed content")
+	tracker.RecordHash("/repo/x.txt", HashContent(content), nil)
+	if err := tracker.CheckConflict("/repo/x.txt", content); err != nil {
+		t.Fatalf("recorded hash should match content, got %v", err)
+	}
+	if err := tracker.CheckConflict("/repo/x.txt", []byte("changed")); err != ErrFileChangedOnDisk {
+		t.Fatalf("changed content should conflict, got %v", err)
+	}
+}
+
 func TestCheckConflictAllowsUntrackedPath(t *testing.T) {
 	tracker := NewFileTracker()
 	// No Record call: a first-touch write has no baseline to conflict against.

internal/tools/grep.go

@@ -1,8 +1,10 @@
 package tools
 
 import (
+	"bufio"
 	"context"
 	"fmt"
+	"io"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -138,84 +140,35 @@ func (tool grepTool) runWith(ctx context.Context, args map[string]any, exclude r
 		}
 	}
 
-	files, err := grepFiles(ctx, resolvedRoot, target, globMatcher, exclude)
-	if err != nil {
-		if res, ok := searchCancelledResult("grep", err); ok {
-			return res
-		}
-		return errorResult("Error running grep: " + err.Error())
-	}
-
-	// resolveScopedPath returns an absolute displayRoot when the target resolved
-	// to an extra (non-workspace) granted root; emit absolute match paths there so
-	// they survive a round-trip through read_file/edit_file (mirrors glob).
-	matches, err := collectGrepMatches(ctx, resolvedRoot, filepath.IsAbs(displayRoot), files, compiled)
-	if err != nil {
-		if res, ok := searchCancelledResult("grep", err); ok {
-			return res
-		}
-		return errorResult("Error running grep: " + err.Error())
-	}
-	if len(matches) == 0 {
-		if outputMode == "count" {
-			return okResult("0 matches found")
-		}
-		return okResult("No matches found.")
-	}
-
+	absolutePaths := filepath.IsAbs(displayRoot)
 	switch outputMode {
 	case "count":
-		total := 0
-		for _, match := range matches {
-			total += match.hits
+		collector := &grepCountCollector{}
+		if err := scanGrepMatches(ctx, resolvedRoot, target, globMatcher, exclude, absolutePaths, exactGrepLineMatcher(compiled), collector.collect); err != nil {
+			if res, ok := searchCancelledResult("grep", err); ok {
+				return res
+			}
+			return errorResult("Error running grep: " + err.Error())
 		}
-		return okResult(fmt.Sprintf("%d matches found", total))
+		return collector.result()
 	case "files_with_matches":
-		seen := map[string]bool{}
-		files := []string{}
-		for _, match := range matches {
-			if !seen[match.file] {
-				seen[match.file] = true
-				files = append(files, match.file)
+		collector := &grepFileListCollector{}
+		if err := scanGrepMatches(ctx, resolvedRoot, target, globMatcher, exclude, absolutePaths, presenceGrepLineMatcher(compiled), collector.collect); err != nil {
+			if res, ok := searchCancelledResult("grep", err); ok {
+				return res
 			}
+			return errorResult("Error running grep: " + err.Error())
 		}
-		sort.Strings(files)
-		budgeted := applyOutputBudget(strings.Join(files, "\n"), searchOutputBudgetBytes, "narrow path/glob/pattern to continue")
-		meta := outputBudgetMeta(budgeted)
-		if budgeted.Truncated {
-			meta["truncated"] = "true"
-			meta["truncation_reason"] = "byte_budget"
-		}
-		return Result{Status: StatusOK, Output: budgeted.Output, Truncated: budgeted.Truncated, Meta: meta}
+		return collector.result()
 	default:
-		lines := make([]string, 0, len(matches))
-		for _, match := range matches {
-			if len(lines) >= headLimit {
-				break
+		collector := &grepContentCollector{headLimit: headLimit}
+		if err := scanGrepMatches(ctx, resolvedRoot, target, globMatcher, exclude, absolutePaths, presenceGrepLineMatcher(compiled), collector.collect); err != nil {
+			if res, ok := searchCancelledResult("grep", err); ok {
+				return res
 			}
-			lines = append(lines, fmt.Sprintf("%s:%d: %s", match.file, match.line, match.text))
-		}
-		truncated := len(matches) > headLimit
-		output := strings.Join(lines, "\n")
-		if truncated {
-			output += fmt.Sprintf("\n\n[truncated: showing first %d of %d matches; narrow path/glob/pattern or increase head_limit]", len(lines), len(matches))
-		}
-		budgeted := applyOutputBudget(output, searchOutputBudgetBytes, "narrow path/glob/pattern or increase head_limit")
-		meta := outputBudgetMeta(budgeted)
-		if truncated || budgeted.Truncated {
-			meta["truncated"] = "true"
-			if budgeted.Truncated {
-				meta["truncation_reason"] = "byte_budget"
-			} else {
-				meta["truncation_reason"] = "head_limit"
-			}
-		}
-		return Result{
-			Status:    StatusOK,
-			Output:    budgeted.Output,
-			Truncated: truncated || budgeted.Truncated,
-			Meta:      meta,
+			return errorResult("Error running grep: " + err.Error())
 		}
+		return collector.result()
 	}
 }
 
@@ -270,33 +223,32 @@ func confineGrepFile(resolvedRoot string, path string) (string, string, bool) {
 	return filepath.ToSlash(relative), resolved, true
 }
 
-func grepFiles(ctx context.Context, resolvedRoot string, target string, globMatcher *regexp.Regexp, exclude readExcluder) ([]string, error) {
+func walkGrepFiles(ctx context.Context, resolvedRoot string, target string, globMatcher *regexp.Regexp, exclude readExcluder, visit func(string) error) error {
 	info, err := os.Stat(target)
 	if err != nil {
-		return nil, err
+		return err
 	}
 
 	if !info.IsDir() {
 		relative, _, ok := confineGrepFile(resolvedRoot, target)
 		if !ok {
-			return []string{}, nil
+			return nil
 		}
 		if shouldSkipWorkspaceFile(relative) {
-			return []string{}, nil
+			return nil
 		}
 		if exclude.fileExcluded(target) {
-			return []string{}, nil
+			return nil
 		}
 		// A single explicit file is matched by its base name so a pattern like
 		// "*.go" applies regardless of how deep the file sits under the workspace.
 		if globMatcher == nil || globMatcher.MatchString(filepath.Base(target)) {
-			return []string{target}, nil
+			return visit(target)
 		}
-		return []string{}, nil
+		return nil
 	}
 
-	files := []string{}
-	err = filepath.WalkDir(target, func(path string, entry os.DirEntry, walkErr error) error {
+	return filepath.WalkDir(target, func(path string, entry os.DirEntry, walkErr error) error {
 		// Checked first, ahead of walkErr: an unscoped search over a large tree
 		// (e.g. a broad parent directory, not just the workspace) can run long
 		// enough that cancelling the run must stop the walk promptly rather than
@@ -347,62 +299,189 @@ func grepFiles(ctx context.Context, resolvedRoot string, target string, globMatc
 			globPath = filepath.ToSlash(rel)
 		}
 		if globMatcher == nil || globMatcher.MatchString(globPath) {
-			files = append(files, path)
+			if err := visit(path); err != nil {
+				return err
+			}
 		}
 		return nil
 	})
-	if err != nil {
-		return nil, err
-	}
-	sort.Strings(files)
-	return files, nil
 }
 
-func collectGrepMatches(ctx context.Context, resolvedRoot string, absolutePaths bool, files []string, compiled *regexp.Regexp) ([]grepMatch, error) {
-	matches := []grepMatch{}
-	for _, file := range files {
-		// Checked per file, matching the walk's per-entry check in grepFiles: a
-		// broad search can already have collected many files before the run is
-		// cancelled, and reading/regex-scanning each one is real work that must
-		// stop promptly rather than running to completion.
+type grepLineMatcher func(string) (int, bool)
+
+func presenceGrepLineMatcher(compiled *regexp.Regexp) grepLineMatcher {
+	return func(line string) (int, bool) {
+		if !compiled.MatchString(line) {
+			return 0, false
+		}
+		return 1, true
+	}
+}
+
+func exactGrepLineMatcher(compiled *regexp.Regexp) grepLineMatcher {
+	return func(line string) (int, bool) {
+		matches := compiled.FindAllStringIndex(line, -1)
+		if len(matches) == 0 {
+			return 0, false
+		}
+		return len(matches), true
+	}
+}
+
+func scanGrepMatches(ctx context.Context, resolvedRoot string, target string, globMatcher *regexp.Regexp, exclude readExcluder, absolutePaths bool, matcher grepLineMatcher, emit func(grepMatch)) error {
+	return walkGrepFiles(ctx, resolvedRoot, target, globMatcher, exclude, func(file string) error {
+		return scanGrepFile(ctx, resolvedRoot, absolutePaths, file, matcher, emit)
+	})
+}
+
+func scanGrepFile(ctx context.Context, resolvedRoot string, absolutePaths bool, file string, matcher grepLineMatcher, emit func(grepMatch)) error {
+	// Re-confine at read time (defense-in-depth) AND to compute the clean
+	// workspace-relative path used in output.
+	relative, resolvedPath, ok := confineGrepFile(resolvedRoot, file)
+	if !ok {
+		return nil
+	}
+	if shouldSkipWorkspaceFile(relative) {
+		return nil
+	}
+	fileLabel := relative
+	if absolutePaths {
+		// Extra-root search: report the absolute, symlink-resolved path
+		// confineGrepFile already validated, so a bare workspace-relative
+		// name can't resolve under the workspace and hit the wrong file when
+		// the same name exists in both roots.
+		fileLabel = filepath.ToSlash(resolvedPath)
+	}
+
+	// Read the symlink-RESOLVED path that confineGrepFile validated, not the
+	// raw candidate, so a symlink swapped in after the check can't escape.
+	handle, err := os.Open(resolvedPath)
+	if err != nil {
+		return nil
+	}
+	defer handle.Close()
+
+	reader := bufio.NewReader(handle)
+	lineNumber := 1
+	sawLine := false
+	lastEnded := false
+	for {
 		if err := ctx.Err(); err != nil {
-			return matches, err
+			return err
 		}
-		// Re-confine at read time (defense-in-depth) AND to compute the clean
-		// workspace-relative path used in output.
-		relative, resolvedPath, ok := confineGrepFile(resolvedRoot, file)
-		if !ok {
-			continue
+		raw, ended, err := readRawLine(reader)
+		if err == io.EOF {
+			if !sawLine || lastEnded {
+				emitGrepLine(matcher, fileLabel, lineNumber, "", emit)
+			}
+			return nil
 		}
-		if shouldSkipWorkspaceFile(relative) {
-			continue
-		}
-		// Read the symlink-RESOLVED path that confineGrepFile validated, not the
-		// raw candidate, so a symlink swapped in after the check can't escape.
-		content, err := os.ReadFile(resolvedPath)
 		if err != nil {
-			continue
+			return nil
 		}
-		for index, line := range strings.Split(strings.ReplaceAll(string(content), "\r\n", "\n"), "\n") {
-			lineMatches := compiled.FindAllStringIndex(line, -1)
-			if len(lineMatches) == 0 {
-				continue
-			}
-			fileLabel := relative
-			if absolutePaths {
-				// Extra-root search: report the absolute, symlink-resolved path
-				// confineGrepFile already validated, so a bare workspace-relative
-				// name can't resolve under the workspace and hit the wrong file when
-				// the same name exists in both roots.
-				fileLabel = filepath.ToSlash(resolvedPath)
-			}
-			matches = append(matches, grepMatch{
-				file: fileLabel,
-				line: index + 1,
-				text: strings.TrimRight(line, "\r"),
-				hits: len(lineMatches),
-			})
+		sawLine = true
+		lastEnded = ended
+		line := strings.TrimRight(string(trimLineBreak(raw, ended)), "\r")
+		emitGrepLine(matcher, fileLabel, lineNumber, line, emit)
+		lineNumber++
+	}
+}
+
+func emitGrepLine(matcher grepLineMatcher, fileLabel string, lineNumber int, line string, emit func(grepMatch)) {
+	hits, ok := matcher(line)
+	if !ok {
+		return
+	}
+	emit(grepMatch{
+		file: fileLabel,
+		line: lineNumber,
+		text: line,
+		hits: hits,
+	})
+}
+
+type grepCountCollector struct {
+	hits int
+}
+
+func (collector *grepCountCollector) collect(match grepMatch) {
+	collector.hits += match.hits
+}
+
+func (collector *grepCountCollector) result() Result {
+	return okResult(fmt.Sprintf("%d matches found", collector.hits))
+}
+
+type grepFileListCollector struct {
+	files []string
+	seen  map[string]bool
+}
+
+func (collector *grepFileListCollector) collect(match grepMatch) {
+	if collector.seen == nil {
+		collector.seen = map[string]bool{}
+	}
+	if collector.seen[match.file] {
+		return
+	}
+	collector.seen[match.file] = true
+	collector.files = append(collector.files, match.file)
+}
+
+func (collector *grepFileListCollector) result() Result {
+	if len(collector.files) == 0 {
+		return okResult("No matches found.")
+	}
+	sort.Strings(collector.files)
+	budgeted := applyOutputBudget(strings.Join(collector.files, "\n"), searchOutputBudgetBytes, "narrow path/glob/pattern to continue")
+	meta := outputBudgetMeta(budgeted)
+	if budgeted.Truncated {
+		meta["truncated"] = "true"
+		meta["truncation_reason"] = "byte_budget"
+	}
+	return Result{Status: StatusOK, Output: budgeted.Output, Truncated: budgeted.Truncated, Meta: meta}
+}
+
+type grepContentCollector struct {
+	headLimit     int
+	matches       []grepMatch
+	matchingLines int
+}
+
+func (collector *grepContentCollector) collect(match grepMatch) {
+	collector.matchingLines++
+	if len(collector.matches) < collector.headLimit {
+		collector.matches = append(collector.matches, match)
+	}
+}
+
+func (collector *grepContentCollector) result() Result {
+	if collector.matchingLines == 0 {
+		return okResult("No matches found.")
+	}
+	lines := make([]string, 0, len(collector.matches))
+	for _, match := range collector.matches {
+		lines = append(lines, fmt.Sprintf("%s:%d: %s", match.file, match.line, match.text))
+	}
+	truncated := collector.matchingLines > collector.headLimit
+	output := strings.Join(lines, "\n")
+	if truncated {
+		output += fmt.Sprintf("\n\n[truncated: showing first %d of %d matches; narrow path/glob/pattern or increase head_limit]", len(lines), collector.matchingLines)
+	}
+	budgeted := applyOutputBudget(output, searchOutputBudgetBytes, "narrow path/glob/pattern or increase head_limit")
+	meta := outputBudgetMeta(budgeted)
+	if truncated || budgeted.Truncated {
+		meta["truncated"] = "true"
+		if budgeted.Truncated {
+			meta["truncation_reason"] = "byte_budget"
+		} else {
+			meta["truncation_reason"] = "head_limit"
 		}
 	}
-	return matches, nil
+	return Result{
+		Status:    StatusOK,
+		Output:    budgeted.Output,
+		Truncated: truncated || budgeted.Truncated,
+		Meta:      meta,
+	}
 }

internal/tools/line_reader.go

@@ -0,0 +1,44 @@
+package tools
+
+import (
+	"bufio"
+	"io"
+)
+
+func readRawLine(reader *bufio.Reader) ([]byte, bool, error) {
+	var line []byte
+	for {
+		fragment, err := reader.ReadSlice('\n')
+		if len(fragment) > 0 {
+			if line != nil || err == bufio.ErrBufferFull {
+				line = append(line, fragment...)
+			} else {
+				line = fragment
+			}
+		}
+		switch err {
+		case nil:
+			return line, true, nil
+		case bufio.ErrBufferFull:
+			continue
+		case io.EOF:
+			if len(line) > 0 {
+				return line, false, nil
+			}
+			return nil, false, io.EOF
+		default:
+			return nil, false, err
+		}
+	}
+}
+
+func trimLineBreak(raw []byte, ended bool) []byte {
+	if !ended || len(raw) == 0 || raw[len(raw)-1] != '\n' {
+		return raw
+	}
+	raw = raw[:len(raw)-1]
+	if len(raw) > 0 && raw[len(raw)-1] == '\r' {
+		raw = raw[:len(raw)-1]
+	}
+	return raw
+}

internal/tools/output_budget.go

@@ -3,6 +3,7 @@ package tools
 import (
 	"fmt"
 	"strconv"
+	"strings"
 )
 
 const (
@@ -52,3 +53,45 @@ func estimatedTokensFromBytes(bytes int) int {
 	}
 	return (bytes + 3) / 4
 }
+
+type outputBudgetBuilder struct {
+	builder  strings.Builder
+	rawBytes int
+	maxBytes int
+	hint     string
+}
+
+func newOutputBudgetBuilder(maxBytes int, hint string) *outputBudgetBuilder {
+	return &outputBudgetBuilder{maxBytes: maxBytes, hint: hint}
+}
+
+func (builder *outputBudgetBuilder) WriteString(value string) {
+	builder.rawBytes += len(value)
+	if builder.maxBytes <= 0 || builder.builder.Len() >= builder.maxBytes {
+		return
+	}
+	remaining := builder.maxBytes - builder.builder.Len()
+	builder.builder.WriteString(utf8Prefix(value, remaining))
+}
+
+func (builder *outputBudgetBuilder) Result() outputBudgetResult {
+	output := builder.builder.String()
+	result := outputBudgetResult{
+		Output:       output,
+		RawBytes:     builder.rawBytes,
+		EmittedBytes: len(output),
+	}
+	if builder.maxBytes <= 0 || builder.rawBytes <= builder.maxBytes {
+		return result
+	}
+
+	marker := fmt.Sprintf("\n\n[truncated: output exceeded %d bytes; %s]", builder.maxBytes, builder.hint)
+	budget := builder.maxBytes - len(marker)
+	if budget < 0 {
+		budget = 0
+	}
+	result.Output = utf8Prefix(output, budget) + marker
+	result.Truncated = true
+	result.EmittedBytes = len(result.Output)
+	return result
+}

internal/tools/read_file.go

@@ -1,8 +1,12 @@
 package tools
 
 import (
+	"bufio"
 	"context"
+	"crypto/sha256"
+	"encoding/hex"
 	"fmt"
+	"io"
 	"os"
 	"strconv"
 	"strings"
@@ -68,7 +72,7 @@ func (tool readFileTool) RunWithOptions(_ context.Context, args map[string]any,
 		return errorResult("Error reading file " + requestedPath + ": " + err.Error())
 	}
 
-	content, err := os.ReadFile(absolutePath)
+	stats, err := scanReadFileStats(absolutePath)
 	if err != nil {
 		return errorResult("Error reading file " + relativePath + ": " + err.Error())
 	}
@@ -76,17 +80,15 @@ func (tool readFileTool) RunWithOptions(_ context.Context, args map[string]any,
 	// write_file read) so a later write can detect an out-of-Zero modification.
 	// Stat is best-effort: a missing FileInfo only drops the diagnostic size/mtime,
 	// not the authoritative content hash.
-	info, _ := os.Stat(absolutePath)
-	options.FileTracker.Record(absolutePath, content, info)
+	options.FileTracker.RecordHash(absolutePath, stats.hash, stats.info)
 
-	normalizedContent := strings.ReplaceAll(string(content), "\r\n", "\n")
-	normalizedContent = strings.TrimSuffix(normalizedContent, "\n")
-	lines := strings.Split(normalizedContent, "\n")
-	total := len(lines)
+	return renderReadFileRange(absolutePath, relativePath, stats.lines, startLine, endLine, maxLines)
+}
+
+func renderReadFileRange(absolutePath string, relativePath string, total int, startLine int, endLine int, maxLines int) Result {
 	if startLine > total {
 		return okResult(fmt.Sprintf("File: %s\n(start_line %d is past the end of the file, which has %d lines)", relativePath, startLine, total))
 	}
-
 	if endLine == 0 || endLine > total {
 		endLine = total
 	}
@@ -94,42 +96,39 @@ func (tool readFileTool) RunWithOptions(_ context.Context, args map[string]any,
 		return errorResult("Error: Invalid arguments for read_file: end_line must be greater than or equal to start_line")
 	}
 
-	selected := lines[startLine-1 : endLine]
 	truncated := false
-	if maxLines > 0 && len(selected) > maxLines {
-		selected = selected[:maxLines]
+	selectedLines := endLine - startLine + 1
+	if maxLines > 0 && selectedLines > maxLines {
+		selectedLines = maxLines
 		truncated = true
 	}
 
-	lastLine := startLine + len(selected) - 1
+	lastLine := startLine + selectedLines - 1
 	width := len(strconv.Itoa(lastLine))
-	numbered := make([]string, 0, len(selected))
-	for index, line := range selected {
-		lineNumber := strconv.Itoa(startLine + index)
-		numbered = append(numbered, strings.Repeat(" ", width-len(lineNumber))+lineNumber+" | "+line)
-	}
-
 	header := fmt.Sprintf("File: %s (%d lines)", relativePath, total)
 	if startLine != 1 || endLine != total || maxLines > 0 {
 		header = fmt.Sprintf("File: %s (lines %d-%d of %d)", relativePath, startLine, lastLine, total)
 	}
 
-	body := strings.Join(numbered, "\n")
+	budgetedOutput := newOutputBudgetBuilder(readOutputBudgetBytes, "use start_line/end_line or max_lines to continue with a smaller range")
+	budgetedOutput.WriteString(header)
+	budgetedOutput.WriteString("\n\n")
+	if err := appendReadFileRange(budgetedOutput, absolutePath, startLine, selectedLines, width); err != nil {
+		return errorResult("Error reading file " + relativePath + ": " + err.Error())
+	}
 	if truncated {
 		// The Truncated flag alone is invisible to the model in the rendered
 		// output, so it cannot tell a max_lines cut from a complete read. Make the
 		// cut explicit and tell it how to continue.
-		body += fmt.Sprintf("\n\n[truncated: %d more line(s) in the requested range not shown; set start_line=%d to continue]", endLine-lastLine, lastLine+1)
+		budgetedOutput.WriteString(fmt.Sprintf("\n\n[truncated: %d more line(s) in the requested range not shown; set start_line=%d to continue]", endLine-lastLine, lastLine+1))
 	}
 
-	output := header + "\n\n" + body
-	budgeted := applyOutputBudget(output, readOutputBudgetBytes, "use start_line/end_line or max_lines to continue with a smaller range")
+	budgeted := budgetedOutput.Result()
 	meta := outputBudgetMeta(budgeted)
 	if budgeted.Truncated {
 		meta["truncated"] = "true"
 		meta["truncation_reason"] = "byte_budget"
 	}
-
 	return Result{
 		Status:    StatusOK,
 		Output:    budgeted.Output,
@@ -137,3 +136,77 @@ func (tool readFileTool) RunWithOptions(_ context.Context, args map[string]any,
 		Meta:      meta,
 	}
 }
+
+type readFileStats struct {
+	lines int
+	hash  string
+	info  os.FileInfo
+}
+
+func scanReadFileStats(path string) (readFileStats, error) {
+	file, err := os.Open(path)
+	if err != nil {
+		return readFileStats{}, err
+	}
+	defer file.Close()
+
+	hasher := sha256.New()
+	reader := bufio.NewReader(file)
+	lines := 0
+	for {
+		raw, _, err := readRawLine(reader)
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return readFileStats{}, err
+		}
+		if _, err := hasher.Write(raw); err != nil {
+			return readFileStats{}, err
+		}
+		lines++
+	}
+	if lines == 0 {
+		lines = 1
+	}
+	info, _ := file.Stat()
+	return readFileStats{lines: lines, hash: hex.EncodeToString(hasher.Sum(nil)), info: info}, nil
+}
+
+func appendReadFileRange(output *outputBudgetBuilder, path string, startLine int, selectedLines int, width int) error {
+	file, err := os.Open(path)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	reader := bufio.NewReader(file)
+	lineNumber := 1
+	emitted := 0
+	for emitted < selectedLines {
+		raw, ended, err := readRawLine(reader)
+		if err == io.EOF {
+			raw = nil
+			ended = false
+		} else if err != nil {
+			return err
+		}
+
+		if lineNumber >= startLine {
+			if emitted > 0 {
+				output.WriteString("\n")
+			}
+			number := strconv.Itoa(lineNumber)
+			output.WriteString(strings.Repeat(" ", width-len(number)))
+			output.WriteString(number)
+			output.WriteString(" | ")
+			output.WriteString(string(trimLineBreak(raw, ended)))
+			emitted++
+		}
+		if err == io.EOF {
+			break
+		}
+		lineNumber++
+	}
+	return nil
+}