fix(cli): enter setup on a requires-model config and hint zero auth login

Two residual first-run gaps after the catalog model-defaulting fix:

- An active provider whose model has NO catalog default to fall back on
  (custom openai-/anthropic-compatible endpoints) still bricked bare
  `zero` and `zero setup` — the exact commands that could have repaired
  the config. Tag that resolve failure with ErrProviderRequiresModel and
  extend the interactive TUI's fixable-error fallback (previously only
  ErrNoActiveProvider) to drop into the setup wizard for it. The sentinel
  is attached via a message-preserving wrapper (multi-target Unwrap), so
  headless commands (zero config / zero exec) print the exact actionable
  text unchanged and every other resolve error stays fatal.

- `zero login` / `zero logout` don't exist (it's `zero auth login`);
  first-run users try them and got only "unknown command" (reported in
  the wild). The unknown-command error now answers: did you mean
  "zero auth login"? Unrelated unknown commands get no suggestion.

Tests: the sentinel comes from a REAL Resolve over a real config file
(message-prefix asserted, no key leak); the TUI fallback is red-green
(reverting the condition reproduces the exact brick with the old error);
the existing no-active-provider fallback and other-errors-stay-fatal
tests still pass; login/logout hint with a no-false-positive check.

.github/workflows/release-artifacts.yml

@@ -54,8 +54,10 @@ jobs:
       # is published under the pushed git tag. If they disagree, install.sh/install.ps1
       # and the npm postinstall all build a download URL that 404s. Fail fast so a
       # forgotten version bump can never publish mis-versioned, un-installable assets.
+      # Matches on the ref (not event_name) because release-please dispatches this
+      # workflow at the tag ref — its GITHUB_TOKEN-created tag cannot fire `push`.
       - name: Check tag matches package.json version
-        if: ${{ github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v') }}
+        if: ${{ startsWith(github.ref, 'refs/tags/v') }}
         shell: bash
         run: |
           pkg_version="$(node -p "require('./package.json').version")"
@@ -78,13 +80,15 @@ jobs:
           path: dist/release/*
           if-no-files-found: error
 
-      # On a `v*` tag push, publish the packaged archive + .sha256 as GitHub Release
-      # assets so the documented `scripts/install.sh` / `install.ps1` path (which reads
-      # /releases/latest) works. Uses the preinstalled `gh` (no new action dependency);
-      # each matrix OS creates the release if absent (best-effort) then uploads its own
-      # assets with --clobber. NOTE: maintainers must push the tag — this never tags.
+      # On a `v*` tag ref (pushed manually, or dispatched at the tag by the
+      # release-please workflow), publish the packaged archive + .sha256 as GitHub
+      # Release assets so the documented `scripts/install.sh` / `install.ps1` path
+      # (which reads /releases/latest) works. Uses the preinstalled `gh` (no new
+      # action dependency); each matrix OS creates the release if absent
+      # (best-effort — release-please normally creates it first) then uploads its
+      # own assets with --clobber. Tags come from merging the release-please PR.
       - name: Publish to GitHub Release
-        if: ${{ github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v') }}
+        if: ${{ startsWith(github.ref, 'refs/tags/v') }}
         shell: bash
         env:
           GH_TOKEN: ${{ github.token }}
@@ -92,3 +96,89 @@ jobs:
           tag="${GITHUB_REF_NAME}"
           gh release create "$tag" --repo "$GITHUB_REPOSITORY" --title "$tag" --generate-notes 2>/dev/null || true
           gh release upload "$tag" dist/release/* --repo "$GITHUB_REPOSITORY" --clobber
+
+  # Publishes the npm wrapper (@gitlawb/zero) once every platform's release
+  # assets are live — the package's postinstall downloads its binary from the
+  # GitHub Release, so publishing before the assets exist would ship a package
+  # that fails to install.
+  #
+  # Auth is npm OIDC trusted publishing: no NPM_TOKEN secret. The package's
+  # npmjs.com settings must list this repo + workflow file as a trusted
+  # publisher, and provenance is then generated automatically. Note npm only
+  # allows configuring a trusted publisher on an EXISTING package, so the very
+  # first @gitlawb/zero publish is a one-time manual `npm publish` bootstrap.
+  publish-npm:
+    name: Publish npm package
+    needs: package
+    if: ${{ startsWith(github.ref, 'refs/tags/v') }}
+    runs-on: ubuntu-latest
+    # Manual approval gate: this environment carries a required-reviewer rule
+    # (Settings -> Environments -> npm-publish), so the job pauses until a
+    # maintainer approves it in the Actions UI before anything reaches npm.
+    environment:
+      name: npm-publish
+      url: https://www.npmjs.com/package/@gitlawb/zero
+    permissions:
+      contents: read
+      id-token: write # OIDC token exchange for npm trusted publishing + provenance
+    steps:
+      - name: Checkout
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
+
+      # No registry-url here on purpose: setup-node's registry-url writes an
+      # .npmrc line referencing $NODE_AUTH_TOKEN, and npm hard-fails on the
+      # unset env var. Trusted publishing needs no token at all.
+      - name: Setup Node
+        uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+        with:
+          node-version: 24
+
+      # OIDC trusted publishing needs npm >= 11.5.1. Use the npm bundled with
+      # the pinned Node toolchain (Node 24 ships >= 11.5.1) rather than pulling
+      # npm@latest from the registry inside the publish path — an unpinned
+      # install there would be avoidable supply-chain exposure. Fail fast if a
+      # future runner/toolchain change ever regresses the bundled npm.
+      - name: Check npm supports trusted publishing
+        run: |
+          npm --version | node -e '
+            const version = require("fs").readFileSync(0, "utf8").trim();
+            const [major, minor, patch] = version.split(".").map(Number);
+            const ok =
+              major > 11 ||
+              (major === 11 && (minor > 5 || (minor === 5 && patch >= 1)));
+            if (!ok) {
+              console.error(
+                `::error::bundled npm ${version} is too old for OIDC trusted ` +
+                  `publishing (needs >= 11.5.1) — bump node-version in this job.`,
+              );
+              process.exit(1);
+            }
+            console.log(`npm ${version} supports trusted publishing.`);
+          '
+
+      # Probe the exact URLs postinstall will build (internal/release/release.go
+      # asset-name scheme) as an anonymous client. This also blocks publishing
+      # while the repo is still private — private release assets 404 without
+      # auth, exactly as they would for an installing user.
+      - name: Verify release assets are downloadable
+        shell: bash
+        run: |
+          version="$(node -p "require('./package.json').version")"
+          base="https://github.com/${GITHUB_REPOSITORY}/releases/download/v${version}"
+          for asset in \
+            "zero-v${version}-linux-x64.tar.gz" \
+            "zero-v${version}-linux-arm64.tar.gz" \
+            "zero-v${version}-macos-x64.tar.gz" \
+            "zero-v${version}-macos-arm64.tar.gz" \
+            "zero-v${version}-windows-x64.zip"; do
+            for url in "${base}/${asset}" "${base}/${asset}.sha256"; do
+              if ! curl -fsSLI -o /dev/null "$url"; then
+                echo "::error::${url} is not publicly downloadable — npm postinstall would fail. Is the repo public and are all assets uploaded?" >&2
+                exit 1
+              fi
+            done
+          done
+          echo "all release assets for v${version} are publicly downloadable."
+
+      - name: Publish to npm
+        run: npm publish --access public

.github/workflows/release-please.yml

@@ -0,0 +1,35 @@
+name: Release Please
+
+on:
+  push:
+    branches:
+      - main
+
+permissions:
+  contents: write # push the release-PR branch, create the tag + GitHub Release
+  pull-requests: write # open/update the release PR
+  issues: write # create/apply release-tracking labels on the release PR
+  actions: write # dispatch release-artifacts.yml once a release is cut
+
+jobs:
+  release-please:
+    name: Release PR / tag
+    runs-on: ubuntu-latest
+    steps:
+      - name: Run release-please
+        id: release
+        uses: googleapis/release-please-action@a02a34c4d625f9be7cb89156071d8567266a2445 # v4.2.0
+
+      # Tags created with the default GITHUB_TOKEN never fire `on: push: tags`
+      # workflows (GitHub suppresses workflows triggered by workflow-created
+      # events), so release-artifacts.yml would not run for a release-please
+      # tag. workflow_dispatch invoked through the API is exempt from that
+      # suppression — dispatch the artifacts build at the new tag explicitly.
+      - name: Build and publish release artifacts
+        if: ${{ steps.release.outputs.release_created }}
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          gh workflow run release-artifacts.yml \
+            --repo "$GITHUB_REPOSITORY" \
+            --ref "${{ steps.release.outputs.tag_name }}"

.release-please-manifest.json

@@ -0,0 +1 @@
+{".":"0.1.0"}

CHANGELOG.md

@@ -6,6 +6,19 @@ 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`.
 
+## 0.1.0 (2026-07-02)
+
+
+### Features
+
+* publish zero to npm via release-please ([#367](https://github.com/Gitlawb/zero/issues/367)) ([8eccc26](https://github.com/Gitlawb/zero/commit/8eccc2669887bc38d35bc16a315c888e4d9ec43a))
+* **tui:** FILES sidebar panel with click-to-select and file drill-in ([#365](https://github.com/Gitlawb/zero/issues/365)) ([142c548](https://github.com/Gitlawb/zero/commit/142c548c89a8652ce300e64ddf1228ee36df7606))
+
+
+### Bug Fixes
+
+* **auth:** propagate credentials to every provider-build surface and pin children to the live provider ([#366](https://github.com/Gitlawb/zero/issues/366)) ([6e0a665](https://github.com/Gitlawb/zero/commit/6e0a665118fe0e09c4b07d482dd18f86045acd2b))
+
 ## [Unreleased]
 
 ### Added

internal/cli/acp.go

@@ -43,8 +43,11 @@ func runACP(args []string, stdout io.Writer, stderr io.Writer, deps appDeps) int
 	conn := acp.NewConn(deps.stdin, stdout)
 	acp.NewAgent(conn, acp.Deps{
 		ResolveConfig: deps.resolveConfig,
-		NewProvider:   deps.newProvider,
-		RunAgent:      agent.Run,
+		// deps.newProvider is wrapped in fillAppDeps to apply the stored API key,
+		// so ACP is authenticated for apiKeyStored profiles like every other
+		// surface — no ACP-specific credential handling needed.
+		NewProvider: deps.newProvider,
+		RunAgent:    agent.Run,
 		// Build the SCOPED registry + sandbox engine per workspace, exactly like the
 		// exec surface, so ACP shell/file tools are confined — never run unconfined.
 		BuildWorkspace: func(workspaceRoot string, resolved config.ResolvedConfig) (*tools.Registry, *sandbox.Engine, error) {

internal/cli/app.go

@@ -43,12 +43,17 @@ import (
 var version = "dev"
 
 type appDeps struct {
-	getwd                 func() (string, error)
-	stdin                 io.Reader
-	userConfigPath        func() (string, error)
-	resolveConfig         func(workspaceRoot string, overrides config.Overrides) (config.ResolvedConfig, error)
-	resolveMCPConfig      func(workspaceRoot string) (config.MCPConfig, error)
-	newProvider           func(config.ProviderProfile) (zeroruntime.Provider, error)
+	getwd            func() (string, error)
+	stdin            io.Reader
+	userConfigPath   func() (string, error)
+	resolveConfig    func(workspaceRoot string, overrides config.Overrides) (config.ResolvedConfig, error)
+	resolveMCPConfig func(workspaceRoot string) (config.MCPConfig, error)
+	newProvider      func(config.ProviderProfile) (zeroruntime.Provider, error)
+	// exportActiveProvider pins spawned children to the run's provider (production:
+	// config.SetActiveProviderEnv, set in defaultAppDeps — deliberately NOT filled
+	// by fillAppDeps, so tests never mutate the process environment unless they
+	// inject it). nil ⇒ no export.
+	exportActiveProvider  func(providerName string)
 	probeProviderHealth   func(context.Context, providerhealth.Options) providerhealth.Result
 	detectLocalRuntimes   func(context.Context, provideronboarding.LocalDetectOptions) []provideronboarding.DetectedLocalRuntime
 	newSessionStore       func() *sessions.Store
@@ -99,9 +104,10 @@ func Run(args []string, stdout io.Writer, stderr io.Writer) int {
 
 func defaultAppDeps() appDeps {
 	return appDeps{
-		getwd:          os.Getwd,
-		stdin:          os.Stdin,
-		userConfigPath: config.DefaultUserConfigPath,
+		getwd:                os.Getwd,
+		stdin:                os.Stdin,
+		userConfigPath:       config.DefaultUserConfigPath,
+		exportActiveProvider: config.SetActiveProviderEnv,
 		resolveConfig: func(workspaceRoot string, overrides config.Overrides) (config.ResolvedConfig, error) {
 			options, err := config.DefaultResolveOptions(workspaceRoot)
 			if err != nil {
@@ -118,9 +124,14 @@ func defaultAppDeps() appDeps {
 			return config.ResolveMCP(options)
 		},
 		newProvider: func(profile config.ProviderProfile) (zeroruntime.Provider, error) {
+			// Resolve the OAuth login ONCE: the bearer resolver and the login key it
+			// bound must describe the same login (the key is passed on to the Codex
+			// account-header resolver so it never re-selects independently).
+			resolver, loginKey := oauthLoginForProfile(profile)
 			return providers.New(profile, providers.Options{
 				UserAgent:     userAgent(),
-				OAuthResolver: oauthResolverForProfile(profile),
+				OAuthResolver: resolver,
+				OAuthLoginKey: loginKey,
 			})
 		},
 		probeProviderHealth: providerhealth.Probe,
@@ -391,6 +402,14 @@ func runWithDeps(args []string, stdout io.Writer, stderr io.Writer, deps appDeps
 		if _, err := fmt.Fprintf(stderr, "unknown command %q\n", args[0]); err != nil {
 			return 1
 		}
+		// First-run users reach for `zero login`/`zero logout` (reported in the
+		// wild); point them at the real command instead of a bare usage pointer.
+		switch strings.ToLower(args[0]) {
+		case "login", "logout":
+			if _, err := fmt.Fprintf(stderr, "did you mean %q?\n", "zero auth "+strings.ToLower(args[0])); err != nil {
+				return 1
+			}
+		}
 		if _, err := fmt.Fprintln(stderr, "Run zero --help for usage."); err != nil {
 			return 1
 		}
@@ -493,6 +512,17 @@ func fillAppDeps(deps appDeps) appDeps {
 	if deps.now == nil {
 		deps.now = defaults.now
 	}
+	// Wrap newProvider ONCE, after all defaults are filled, so every surface that
+	// builds the runtime provider gets the credential-store key applied. The
+	// resolver is pure and leaves apiKeyStored profiles keyless; an unwrapped
+	// build sends unauthenticated requests. config.ApplyStoredAPIKey is a no-op
+	// when the key is already set or the profile isn't stored-key, so this is
+	// safe and idempotent for every profile kind and every injected newProvider.
+	baseNewProvider := deps.newProvider
+	userConfigPath := deps.userConfigPath
+	deps.newProvider = func(profile config.ProviderProfile) (zeroruntime.Provider, error) {
+		return baseNewProvider(applyStoredProviderKeyAt(profile, userConfigPath))
+	}
 	return deps
 }
 
@@ -508,7 +538,21 @@ func runInteractiveTUIWithSetup(stderr io.Writer, deps appDeps, permissionMode a
 
 	resolved, err := deps.resolveConfig(workspaceRoot, config.Overrides{})
 	if err != nil {
-		return writeAppError(stderr, err.Error(), 1)
+		// A resolve failure the setup wizard can FIX is not fatal for the
+		// interactive TUI: drop into the wizard with an empty config so the user
+		// can onboard/repair, instead of exiting with an error they can only fix
+		// by hand-editing config.json. That covers a missing/unresolvable active
+		// provider and an active provider without a model (custom endpoints have
+		// no catalog default) — previously the second shape bricked bare `zero`
+		// and `zero setup`, the exact commands that could have fixed it. Any
+		// other error (malformed JSON, directory conflict, etc.) is still fatal,
+		// and headless commands (zero config / zero exec) still fail with the
+		// actionable message.
+		if !errors.Is(err, config.ErrNoActiveProvider) && !errors.Is(err, config.ErrProviderRequiresModel) {
+			return writeAppError(stderr, err.Error(), 1)
+		}
+		resolved = config.ResolvedConfig{}
+		forceSetup = true
 	}
 	userConfigPath, err := deps.userConfigPath()
 	if err != nil {
@@ -720,20 +764,50 @@ func tuiSandboxSetupCommand(backend sandbox.Backend, deps appDeps) func(context.
 	}
 }
 
+// buildProvider constructs the run's provider at STARTUP — it is called only from
+// the two launch paths (interactive TUI and headless exec), never from mid-run
+// rebuilds (escalation, wizard, ACP go through deps.newProvider directly).
 func buildProvider(resolved config.ResolvedConfig, deps appDeps) (zeroruntime.Provider, error) {
 	if !config.HasProviderProfile(resolved.Provider) {
 		return nil, nil
 	}
-	// Load the API key from the encrypted credential store when it isn't already
-	// resolved from inline config or an env var. This keeps the resolver pure (no
-	// I/O) and is a no-op for env/inline-key providers and when nothing is stored.
-	profile := resolved.Provider
-	if path, perr := deps.userConfigPath(); perr == nil {
+	// deps.newProvider is wrapped in fillAppDeps to apply the stored key, so this
+	// (and every other newProvider caller) needs no per-site key handling.
+	provider, err := deps.newProvider(resolved.Provider)
+	if err != nil {
+		return nil, err
+	}
+	// Pin spawned children (sub-agents / swarm members inherit the environment) to
+	// THIS run's provider from launch, not only after an in-session switch. Without
+	// the launch-time export a child re-resolves config.json at spawn time, so a
+	// provider switch persisted by ANOTHER zero process mid-session would silently
+	// move new children onto a different provider (and different credentials) than
+	// the parent is running. Runtime switches (/model, /provider, wizard,
+	// onboarding) re-export on commit, keeping the pin current. Injected via deps
+	// (nil in tests) because it mutates the process environment.
+	if deps.exportActiveProvider != nil {
+		deps.exportActiveProvider(resolved.Provider.Name)
+	}
+	return provider, nil
+}
+
+// applyStoredProviderKeyAt loads the API key from the encrypted credential store
+// when the resolver left it empty (the resolver is pure — no I/O — so an
+// apiKeyStored profile reaches this layer keyless). No-op for inline/env-key
+// providers and when nothing is stored. This is applied once, centrally, by the
+// deps.newProvider wrapper in fillAppDeps so EVERY surface that builds a runtime
+// provider (headless exec, the ACP builder, exec's mid-run escalation switcher,
+// and any future caller) is covered without a per-site invariant to forget.
+func applyStoredProviderKeyAt(profile config.ProviderProfile, userConfigPath func() (string, error)) config.ProviderProfile {
+	if userConfigPath == nil {
+		return profile
+	}
+	if path, perr := userConfigPath(); perr == nil {
 		if store, err := config.ProviderKeyStoreAt(filepath.Dir(path)); err == nil {
 			profile = config.ApplyStoredAPIKey(profile, store)
 		}
 	}
-	return deps.newProvider(profile)
+	return profile
 }
 
 func newCoreRegistry(workspaceRoot string) *tools.Registry {

internal/cli/app_test.go

@@ -5,6 +5,7 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"io"
 	"os"
 	"path/filepath"
@@ -157,6 +158,80 @@ func TestRunNoArgsLaunchesSetupTUIWithNilProviderWhenNoProviderConfigured(t *tes
 	assertAgentOptions(t, launchedOptions, 12, agent.PermissionModeAsk)
 }
 
+func TestRunNoArgsEntersSetupWhenResolveReportsNoActiveProvider(t *testing.T) {
+	var stdout bytes.Buffer
+	var stderr bytes.Buffer
+	cwd := t.TempDir()
+	setCLIUserConfigRoot(t)
+	userConfigPath := filepath.Join(t.TempDir(), "zero", "config.json")
+	var launchedOptions tui.Options
+	launched := false
+
+	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{}, fmt.Errorf("%w: active provider %q not found", config.ErrNoActiveProvider, "ghost")
+		},
+		newProvider: func(config.ProviderProfile) (zeroruntime.Provider, error) {
+			t.Fatal("newProvider should not be called without a resolved provider")
+			return nil, nil
+		},
+		userConfigPath: func() (string, error) {
+			return userConfigPath, nil
+		},
+		registerMCPTools: func(context.Context, *tools.Registry, config.MCPConfig, mcp.RegisterOptions) (mcpToolRuntime, error) {
+			return noopMCPRuntime{}, nil
+		},
+		runTUI: func(ctx context.Context, options tui.Options) int {
+			launched = true
+			launchedOptions = options
+			return 0
+		},
+	})
+
+	if exitCode != 0 {
+		t.Fatalf("exit code = %d, want 0 (setup TUI launched), stderr=%q", exitCode, stderr.String())
+	}
+	if !launched {
+		t.Fatal("TUI was not launched; expected fallback into setup instead of a fatal error")
+	}
+	if !launchedOptions.Setup.Visible || !launchedOptions.Setup.Required {
+		t.Fatalf("Setup = %#v, want visible required setup", launchedOptions.Setup)
+	}
+	if launchedOptions.Provider != nil {
+		t.Fatalf("Provider = %#v, want nil for no-provider fallback", launchedOptions.Provider)
+	}
+}
+
+func TestRunNoArgsFailsWhenResolveErrorIsNotProviderRelated(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{}, fmt.Errorf("invalid config JSON")
+		},
+		runTUI: func(ctx context.Context, options tui.Options) int {
+			t.Fatal("TUI must not launch on a non-provider resolve error")
+			return 0
+		},
+	})
+
+	if exitCode == 0 {
+		t.Fatal("exit code = 0, want non-zero for fatal config error")
+	}
+	if !strings.Contains(stderr.String(), "invalid config JSON") {
+		t.Fatalf("stderr = %q, want the underlying config error", stderr.String())
+	}
+}
+
 func TestRunNoArgsLaunchesTUIWithMCPState(t *testing.T) {
 	var stdout bytes.Buffer
 	var stderr bytes.Buffer
@@ -1401,3 +1476,75 @@ func TestRunThemeFlagRejectsBadValue(t *testing.T) {
 		t.Fatalf("expected a clear --theme error, got %q", stderr.String())
 	}
 }
+
+// A custom endpoint saved without a model previously bricked bare `zero` and
+// `zero setup` — the exact commands that could have fixed it (the resolve
+// error escaped before the wizard could open). The interactive TUI now treats
+// the requires-model failure as "needs onboarding", same as a missing active
+// provider. The error comes from a REAL Resolve over a real config file, so
+// this exercises the production sentinel wrapping, not a hand-built error.
+func TestRunNoArgsEntersSetupWhenActiveProviderMissesModel(t *testing.T) {
+	var stdout bytes.Buffer
+	var stderr bytes.Buffer
+	cwd := t.TempDir()
+	setCLIUserConfigRoot(t)
+	brokenConfig := filepath.Join(t.TempDir(), "config.json")
+	if err := os.WriteFile(brokenConfig, []byte(`{
+		"activeProvider": "gw",
+		"providers": [{"name": "gw", "provider_kind": "openai-compatible", "baseURL": "https://gw.example/v1", "apiKey": "sk-x"}]
+	}`), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	launched := false
+	var launchedOptions tui.Options
+
+	exitCode := runWithDeps([]string{}, &stdout, &stderr, appDeps{
+		getwd: func() (string, error) { return cwd, nil },
+		resolveConfig: func(string, config.Overrides) (config.ResolvedConfig, error) {
+			return config.Resolve(config.ResolveOptions{UserConfigPath: brokenConfig, Env: map[string]string{}})
+		},
+		newProvider: func(config.ProviderProfile) (zeroruntime.Provider, error) {
+			t.Fatal("newProvider must not be called without a resolved provider")
+			return nil, nil
+		},
+		userConfigPath: func() (string, error) { return filepath.Join(t.TempDir(), "zero", "config.json"), nil },
+		registerMCPTools: func(context.Context, *tools.Registry, config.MCPConfig, mcp.RegisterOptions) (mcpToolRuntime, error) {
+			return noopMCPRuntime{}, nil
+		},
+		runTUI: func(_ context.Context, options tui.Options) int {
+			launched = true
+			launchedOptions = options
+			return 0
+		},
+	})
+
+	if exitCode != 0 {
+		t.Fatalf("exit code = %d, want 0 (setup TUI launched), stderr=%q", exitCode, stderr.String())
+	}
+	if !launched {
+		t.Fatal("TUI was not launched; a fixable requires-model config must fall into setup, not exit fatally")
+	}
+	if !launchedOptions.Setup.Visible || !launchedOptions.Setup.Required {
+		t.Fatalf("Setup = %#v, want visible required setup", launchedOptions.Setup)
+	}
+}
+
+// `zero login`/`zero logout` don't exist (it's `zero auth login`); first-run
+// users try them (reported in the wild), so the unknown-command error points at
+// the real command.
+func TestRunUnknownLoginSuggestsAuthLogin(t *testing.T) {
+	var stdout, stderr bytes.Buffer
+	exitCode := runWithDeps([]string{"login"}, &stdout, &stderr, appDeps{})
+	if exitCode != 2 {
+		t.Fatalf("exit = %d, want 2 (unknown command)", exitCode)
+	}
+	if !strings.Contains(stderr.String(), `"zero auth login"`) {
+		t.Fatalf("stderr = %q, want a zero auth login suggestion", stderr.String())
+	}
+	// An unrelated unknown command gets no misleading suggestion.
+	stderr.Reset()
+	runWithDeps([]string{"frobnicate"}, &stdout, &stderr, appDeps{})
+	if strings.Contains(stderr.String(), "did you mean") {
+		t.Fatalf("stderr = %q, unrelated commands must not get the auth hint", stderr.String())
+	}
+}

internal/cli/auth_propagation_test.go

@@ -0,0 +1,180 @@
+package cli
+
+import (
+	"bytes"
+	"errors"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/Gitlawb/zero/internal/config"
+	"github.com/Gitlawb/zero/internal/zeroruntime"
+)
+
+// seedStoredProviderKey writes key into a credential store rooted beside the
+// returned config path, and returns deps fields wired at that path — the same
+// layout applyStoredProviderKey resolves through in production.
+func seedStoredProviderKey(t *testing.T, providerName, key string) (userConfigPath string) {
+	t.Helper()
+	t.Setenv("ZERO_CRED_STORAGE", "encrypted-file") // never touch the real OS keychain in tests
+	dir := t.TempDir()
+	store, err := config.ProviderKeyStoreAt(dir)
+	if err != nil {
+		t.Fatalf("ProviderKeyStoreAt: %v", err)
+	}
+	if err := store.Set(providerName, key); err != nil {
+		t.Fatalf("seed stored key: %v", err)
+	}
+	return filepath.Join(dir, "config.json")
+}
+
+// applyStoredProviderKeyAt must fill APIKey from the credential store for an
+// apiKeyStored profile — the single central helper the newProvider wrapper uses.
+func TestApplyStoredProviderKeyAtFillsFromCredstore(t *testing.T) {
+	configPath := seedStoredProviderKey(t, "echo", "sk-stored-test")
+	ucp := func() (string, error) { return configPath, nil }
+
+	stored := applyStoredProviderKeyAt(config.ProviderProfile{Name: "echo", APIKeyStored: true}, ucp)
+	if stored.APIKey != "sk-stored-test" {
+		t.Fatalf("APIKey = %q, want the stored key", stored.APIKey)
+	}
+
+	// A profile that did NOT opt into stored-key auth must be left unchanged —
+	// a stale store entry must not silently reactivate credentials.
+	plain := applyStoredProviderKeyAt(config.ProviderProfile{Name: "echo"}, ucp)
+	if plain.APIKey != "" {
+		t.Fatalf("non-stored profile APIKey = %q, want empty", plain.APIKey)
+	}
+}
+
+// fillAppDeps wraps newProvider so EVERY surface that builds a runtime provider
+// (buildProvider, the ACP builder — which is just deps.newProvider — and exec's
+// escalation switcher) gets the stored key applied. Passing the raw resolved
+// profile previously sent unauthenticated requests for apiKeyStored profiles,
+// the default onboarding outcome. Testing the wrap covers all those surfaces.
+func TestFillAppDepsWrapsNewProviderWithStoredKey(t *testing.T) {
+	configPath := seedStoredProviderKey(t, "echo", "sk-stored-wrap")
+
+	var captured config.ProviderProfile
+	deps := fillAppDeps(appDeps{
+		userConfigPath: func() (string, error) { return configPath, nil },
+		newProvider: func(profile config.ProviderProfile) (zeroruntime.Provider, error) {
+			captured = profile
+			return nil, nil // only the captured profile matters here
+		},
+	})
+
+	if _, err := deps.newProvider(config.ProviderProfile{Name: "echo", APIKeyStored: true}); err != nil {
+		t.Fatalf("wrapped newProvider: %v", err)
+	}
+	if captured.APIKey != "sk-stored-wrap" {
+		t.Fatalf("wrapped newProvider built with APIKey = %q, want the stored key (unauthenticated regression)", captured.APIKey)
+	}
+}
+
+// buildProvider (the TUI/exec STARTUP construction site) must export
+// ZERO_PROVIDER so children spawned at any point in the run are pinned to the
+// parent's provider from launch — not only after an in-session switch. Without
+// this, a provider switch persisted by another zero process mid-session moves
+// new children onto a different provider (and credentials) than the parent.
+func TestBuildProviderExportsActiveProviderEnv(t *testing.T) {
+	t.Setenv(config.ActiveProviderEnv, "stale-from-elsewhere")
+	// The exporter is injected (defaultAppDeps wires config.SetActiveProviderEnv;
+	// fillAppDeps deliberately leaves it nil so ordinary tests never mutate the
+	// process env). Inject the real one here to assert the actual env effect.
+	deps := appDeps{
+		exportActiveProvider: config.SetActiveProviderEnv,
+		newProvider: func(config.ProviderProfile) (zeroruntime.Provider, error) {
+			return nil, nil
+		},
+	}
+
+	resolved := config.ResolvedConfig{Provider: config.ProviderProfile{Name: "pinned", ProviderKind: config.ProviderKindAnthropic, Model: "m"}}
+	if _, err := buildProvider(resolved, deps); err != nil {
+		t.Fatalf("buildProvider: %v", err)
+	}
+	if got := os.Getenv(config.ActiveProviderEnv); got != "pinned" {
+		t.Fatalf("%s = %q after startup build, want %q (children would spawn on the stale provider)", config.ActiveProviderEnv, got, "pinned")
+	}
+
+	// A FAILED build must not move the pin: the process never committed to the
+	// new provider, so children must keep resolving whatever was in effect.
+	t.Setenv(config.ActiveProviderEnv, "still-current")
+	failing := appDeps{
+		exportActiveProvider: config.SetActiveProviderEnv,
+		newProvider: func(config.ProviderProfile) (zeroruntime.Provider, error) {
+			return nil, errors.New("boom")
+		},
+	}
+	if _, err := buildProvider(resolved, failing); err == nil {
+		t.Fatal("expected build error")
+	}
+	if got := os.Getenv(config.ActiveProviderEnv); got != "still-current" {
+		t.Fatalf("%s = %q after failed build, want it untouched", config.ActiveProviderEnv, got)
+	}
+
+	// No provider profile at all → no provider, no pin change.
+	if _, err := buildProvider(config.ResolvedConfig{}, deps); err != nil {
+		t.Fatalf("buildProvider(empty): %v", err)
+	}
+	if got := os.Getenv(config.ActiveProviderEnv); got != "still-current" {
+		t.Fatalf("%s = %q after profile-less build, want it untouched", config.ActiveProviderEnv, got)
+	}
+}
+
+// A mid-run --allow-escalation model switch previously rebuilt the provider
+// from the PURE resolved profile (the stored key lives only in buildProvider's
+// local copy), so the escalated provider was keyless and the next completion
+// call 401'd mid-run. Every profile handed to newProvider on this path must
+// carry the stored key.
+func TestRunExecEscalationSwitchKeepsStoredKey(t *testing.T) {
+	dataHome := t.TempDir()
+	t.Setenv("XDG_DATA_HOME", dataHome)
+	cwd := t.TempDir()
+
+	if _, ok := mustUpgradeTarget(t, "claude-haiku-4.5"); !ok {
+		t.Skip("registry has no upgrade target for claude-haiku-4.5")
+	}
+
+	configPath := seedStoredProviderKey(t, "echo", "sk-stored-escalation")
+
+	var builtProfiles []config.ProviderProfile
+	var stdout, stderr bytes.Buffer
+	exitCode := runWithDeps([]string{
+		"exec",
+		"--allow-escalation",
+		"--model", "claude-haiku-4.5",
+		"--init-session-id", "escalation_stored_key_run",
+		"escalate please",
+	}, &stdout, &stderr, appDeps{
+		getwd:          func() (string, error) { return cwd, nil },
+		userConfigPath: func() (string, error) { return configPath, nil },
+		resolveConfig: func(_ string, overrides config.Overrides) (config.ResolvedConfig, error) {
+			model := "claude-haiku-4.5"
+			if overrides.Provider.Model != "" {
+				model = overrides.Provider.Model
+			}
+			cfg := execResolvedConfig()
+			cfg.Provider.ProviderKind = config.ProviderKindAnthropic
+			cfg.Provider.Model = model
+			cfg.Provider.APIKeyStored = true // key lives ONLY in the credstore
+			cfg.MaxTurns = 3
+			return cfg, nil
+		},
+		newProvider: func(profile config.ProviderProfile) (zeroruntime.Provider, error) {
+			builtProfiles = append(builtProfiles, profile)
+			return &usageEmittingEscalatingProvider{escalate: len(builtProfiles) == 1}, nil
+		},
+	})
+	if exitCode != exitSuccess {
+		t.Fatalf("exit = %d, want success; stderr=%s", exitCode, stderr.String())
+	}
+	if len(builtProfiles) < 2 {
+		t.Fatalf("want at least 2 provider builds (initial + escalated), got %d", len(builtProfiles))
+	}
+	for i, profile := range builtProfiles {
+		if profile.APIKey != "sk-stored-escalation" {
+			t.Fatalf("provider build %d APIKey = %q, want the stored key (escalated build went out keyless)", i, profile.APIKey)
+		}
+	}
+}

internal/cli/exec.go

@@ -365,6 +365,9 @@ func runExec(args []string, stdout io.Writer, stderr io.Writer, deps appDeps) in
 	var modelSwitcher func(context.Context, string) (agent.Provider, error)
 	if options.allowEscalation {
 		modelSwitcher = func(_ context.Context, modelID string) (agent.Provider, error) {
+			// deps.newProvider is wrapped (fillAppDeps) to apply the stored key, so
+			// the escalated provider is authenticated even though resolved.Provider
+			// is the pure profile — no per-site key handling here.
 			switchedProfile := resolved.Provider
 			switchedProfile.Model = modelID
 			switchedProvider, err := deps.newProvider(switchedProfile)

internal/cli/oauth_credential_test.go

@@ -24,6 +24,7 @@ func TestProviderHasOAuthLogin(t *testing.T) {
 
 func TestSetupRequiredRecognizesOAuthLogin(t *testing.T) {
 	path := filepath.Join(t.TempDir(), "tok.json")
+	t.Setenv("ZERO_OAUTH_STORAGE", "file") // an inherited "keyring" would ignore the temp path and hit the OS keychain
 	t.Setenv("ZERO_OAUTH_TOKENS_PATH", path)
 	store, err := oauth.NewStore(oauth.StoreOptions{FilePath: path})
 	if err != nil {
@@ -45,3 +46,88 @@ func TestSetupRequiredRecognizesOAuthLogin(t *testing.T) {
 		t.Fatal("a keyless provider with no OAuth login must require onboarding")
 	}
 }
+
+// A profile renamed away from its catalog ID must still get a runtime OAuth
+// resolver when the login is stored under the catalog name — and a CASE-VARIANT
+// profile name must not drop the catalog-ID candidate (the store is
+// case-sensitive; a case-insensitive dedupe would swallow it).
+func TestOAuthResolverForProfileFallsBackToCatalogID(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "tok.json")
+	t.Setenv("ZERO_OAUTH_STORAGE", "file") // an inherited "keyring" would ignore the temp path and hit the OS keychain
+	t.Setenv("ZERO_OAUTH_TOKENS_PATH", path)
+	store, err := oauth.NewStore(oauth.StoreOptions{FilePath: path})
+	if err != nil {
+		t.Fatalf("NewStore: %v", err)
+	}
+	if err := store.Save(oauth.ProviderKey("chatgpt"), oauth.Token{AccessToken: "tok", ExpiresAt: time.Now().Add(time.Hour)}); err != nil {
+		t.Fatalf("seed token: %v", err)
+	}
+
+	// A renamed profile resolves the catalog-ID login, and the returned key MUST be
+	// that login's key — the same key the Codex account-header resolver reads from,
+	// so bearer and account can never come from different logins.
+	if resolver, key := oauthLoginForProfile(config.ProviderProfile{Name: "codex", CatalogID: "chatgpt"}); resolver == nil {
+		t.Fatal("renamed profile with a catalog-ID login must get a resolver (unauthenticated-children regression)")
+	} else if key != oauth.ProviderKey("chatgpt") {
+		t.Fatalf("bound key = %q, want the chatgpt login key (bearer/account must share it)", key)
+	}
+	// Name differs from catalog ID only in CASE: the exact-case store key is
+	// "provider:chatgpt", so "chatgpt" must survive as a distinct candidate.
+	if resolver, key := oauthLoginForProfile(config.ProviderProfile{Name: "ChatGPT", CatalogID: "chatgpt"}); resolver == nil {
+		t.Fatal("case-variant profile name must still resolve the catalog-ID login (case-insensitive dedupe regression)")
+	} else if key != oauth.ProviderKey("chatgpt") {
+		t.Fatalf("case-variant bound key = %q, want the chatgpt login key", key)
+	}
+	if resolver, _ := oauthLoginForProfile(config.ProviderProfile{Name: "chatgpt", CatalogID: "chatgpt"}); resolver == nil {
+		t.Fatal("catalog-named profile must get a resolver")
+	}
+	if resolver, key := oauthLoginForProfile(config.ProviderProfile{Name: "openai", CatalogID: "openai"}); resolver != nil || key != "" {
+		t.Fatalf("a profile with no stored login must get no resolver and an empty key, got key=%q", key)
+	}
+}
+
+// The catalog-ID fallback must NOT reach a sibling profile's OAuth login when
+// this profile has its own key — withBearer would erase the key and silently
+// bill the model call under the sibling's account (a real cross-profile
+// override the fallback introduced). A profile WITH its own resolved key gets no
+// resolver even when a catalog-shared login exists.
+func TestOAuthResolverForProfileDoesNotOverrideExplicitKey(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "tok.json")
+	t.Setenv("ZERO_OAUTH_STORAGE", "file") // an inherited "keyring" would ignore the temp path and hit the OS keychain
+	t.Setenv("ZERO_OAUTH_TOKENS_PATH", path)
+	store, err := oauth.NewStore(oauth.StoreOptions{FilePath: path})
+	if err != nil {
+		t.Fatalf("NewStore: %v", err)
+	}
+	// A personal login stored under the catalog name.
+	if err := store.Save(oauth.ProviderKey("anthropic"), oauth.Token{AccessToken: "personal-tok", ExpiresAt: time.Now().Add(time.Hour)}); err != nil {
+		t.Fatalf("seed token: %v", err)
+	}
+
+	// Work profile: same catalog, its OWN resolved API key, deliberately NOT the
+	// personal OAuth account. It must keep using its key (no resolver attached).
+	work := config.ProviderProfile{Name: "anthropic-work", CatalogID: "anthropic", APIKey: "sk-work-key"}
+	if resolver, key := oauthLoginForProfile(work); resolver != nil || key != "" {
+		t.Fatalf("a profile with its own API key must not get a catalog-shared OAuth resolver (cross-profile override), got key=%q", key)
+	}
+	// A raw auth-header credential must be protected the same way.
+	header := config.ProviderProfile{Name: "anthropic-hdr", CatalogID: "anthropic", AuthHeaderValue: "Bearer byo"}
+	if resolver, _ := oauthLoginForProfile(header); resolver != nil {
+		t.Fatal("a profile with its own auth header must not get a catalog-shared OAuth resolver")
+	}
+	// A same-NAME login must not override an explicit key either (the name
+	// candidate is gated on the profile being keyless, not just the catalog one).
+	if err := store.Save(oauth.ProviderKey("anthropic-work"), oauth.Token{AccessToken: "name-tok", ExpiresAt: time.Now().Add(time.Hour)}); err != nil {
+		t.Fatalf("seed name token: %v", err)
+	}
+	if resolver, _ := oauthLoginForProfile(work); resolver != nil {
+		t.Fatal("a profile with its own API key must not get an OAuth resolver even from a same-name login")
+	}
+	// Sanity: a keyless sibling on the same catalog DOES resolve the shared login.
+	keyless := config.ProviderProfile{Name: "anthropic-oauth", CatalogID: "anthropic"}
+	if resolver, key := oauthLoginForProfile(keyless); resolver == nil {
+		t.Fatal("a keyless profile should still resolve the catalog-shared login")
+	} else if key != oauth.ProviderKey("anthropic") {
+		t.Fatalf("keyless sibling bound key = %q, want the catalog login key", key)
+	}
+}

internal/cli/oauth_provider.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"errors"
 	"net/http"
-	"strings"
 	"time"
 
 	"github.com/Gitlawb/zero/internal/config"
@@ -12,33 +11,36 @@ import (
 	"github.com/Gitlawb/zero/internal/providers/providerio"
 )
 
-// providerOAuthName resolves the OAuth login name for a provider profile. It is
-// the name a user logs in under (`zero auth login <name>`) whose token then
-// authenticates this provider's model calls. For now it is the profile name;
-// the provider presets map well-known kinds (openai/anthropic) to canonical
-// names on top of this.
-func providerOAuthName(profile config.ProviderProfile) string {
-	return strings.TrimSpace(profile.Name)
-}
-
-// oauthResolverForProfile returns a TokenResolver that authenticates a provider's
-// model calls with the user's OAuth login, or nil when no login exists for this
-// provider. Returning nil for the no-login case keeps API-key users free of any
-// per-request store lookups: the resolver is only attached once a login is
-// present at construction time.
-func oauthResolverForProfile(profile config.ProviderProfile) providerio.TokenResolver {
-	name := providerOAuthName(profile)
-	if name == "" {
-		return nil
+// oauthLoginForProfile resolves the user's OAuth login for a provider ONCE and
+// returns both a TokenResolver that authenticates model calls with it and the
+// credential-store key it bound to. It returns (nil, "") when no login exists —
+// keeping API-key users free of any per-request store lookups, since the resolver
+// is only attached when a login is present at construction time.
+//
+// The returned key is the single source of truth for "which login is this
+// provider using": callers pass it to providers.Options.OAuthLoginKey so the
+// Codex chatgpt-account-id header reads its account from the exact login that
+// issued the bearer token, instead of doing a second, independent lookup that
+// could select a different login (a backend-rejected mismatch).
+//
+// Candidate login names (profile name, then a catalog-ID fallback, both gated on
+// the profile having no own configured credential) come from the shared
+// ProviderProfile.OAuthLoginCandidates so the runtime resolver, the Codex account
+// resolver, and the onboarding presence check never diverge.
+func oauthLoginForProfile(profile config.ProviderProfile) (providerio.TokenResolver, string) {
+	candidates := profile.OAuthLoginCandidates()
+	if len(candidates) == 0 {
+		return nil, ""
 	}
 	store, err := oauth.NewStore(oauth.StoreOptions{})
 	if err != nil {
-		return nil
+		return nil, ""
 	}
-	key := oauth.ProviderKey(name)
-	if _, ok, loadErr := store.Load(key); loadErr != nil || !ok {
-		// No login (or an unreadable/invalid key) → API-key auth, no resolver.
-		return nil
+	_, key, ok := oauth.FirstStored(store, candidates)
+	if !ok {
+		// No login under any candidate (or unreadable/invalid keys) → API-key
+		// auth, no resolver.
+		return nil, ""
 	}
 	manager, err := oauth.NewManager(oauth.ManagerOptions{
 		Store:      store,
@@ -48,9 +50,9 @@ func oauthResolverForProfile(profile config.ProviderProfile) providerio.TokenRes
 		AllowPresets: true,
 	})
 	if err != nil {
-		return nil
+		return nil, ""
 	}
-	return func(ctx context.Context, forceRefresh bool) (string, string, bool, error) {
+	resolver := func(ctx context.Context, forceRefresh bool) (string, string, bool, error) {
 		var token string
 		var rerr error
 		if forceRefresh {
@@ -67,4 +69,5 @@ func oauthResolverForProfile(profile config.ProviderProfile) providerio.TokenRes
 		}
 		return "Authorization", "Bearer " + token, true, nil
 	}
+	return resolver, key
 }

internal/cli/provider_setup.go

@@ -488,7 +488,7 @@ func validateProviderRuntimeReady(profile config.ProviderProfile) error {
 }
 
 func providerProfileHasCredential(profile config.ProviderProfile) bool {
-	return strings.TrimSpace(profile.APIKey) != "" || profile.APIKeyStored || strings.TrimSpace(profile.AuthHeaderValue) != ""
+	return profile.HasConfiguredCredential()
 }
 
 func providerKindForDescriptor(descriptor providercatalog.Descriptor) config.ProviderKind {

internal/cli/setup.go

@@ -314,10 +314,14 @@ func setupRequired(resolved config.ResolvedConfig) bool {
 }
 
 // providerHasOAuthLogin reports whether a stored OAuth login exists for the
-// provider, keyed by its profile name or catalog id.
+// provider. It uses the same ProviderProfile.OAuthLoginCandidates the runtime
+// resolver does, so the "authenticated in the UI" gate and the "authenticated at
+// runtime" resolver can never diverge. This is only consulted for a profile with
+// no usable API-key credential (setupRequired returns early otherwise), where
+// the candidate set is permissive (profile name + catalog ID).
 func providerHasOAuthLogin(profile config.ProviderProfile, oauthLogins map[string]bool) bool {
-	for _, name := range []string{strings.TrimSpace(profile.Name), strings.TrimSpace(profile.CatalogID)} {
-		if name != "" && oauthLogins[name] {
+	for _, name := range profile.OAuthLoginCandidates() {
+		if oauthLogins[name] {
 			return true
 		}
 	}

internal/cli/specialist_test.go

@@ -8,6 +8,8 @@ import (
 	"runtime"
 	"strings"
 	"testing"
+
+	"github.com/Gitlawb/zero/internal/config"
 )
 
 func TestRunSpecialistListShowAndPath(t *testing.T) {
@@ -326,7 +328,7 @@ func setSpecialistConfigRoot(t *testing.T) string {
 	default:
 		t.Setenv("XDG_CONFIG_HOME", root)
 	}
-	configRoot, err := os.UserConfigDir()
+	configRoot, err := config.UserConfigDir()
 	if err != nil {
 		t.Fatalf("UserConfigDir() error = %v", err)
 	}

internal/config/credentials.go

@@ -155,6 +155,63 @@ func MigratePlaintextProviderKeys(path string, store APIKeySetter) (int, error)
 	return migrated, nil
 }
 
+// HasConfiguredCredential reports whether the profile is set up to authenticate
+// with its own API key (inline, stored, or a raw auth header). It is the single
+// definition of "this profile is key-authed", shared by OAuthLoginCandidates and
+// the cli/tui setup surfaces so they never disagree about whether a profile is
+// keyed. APIKeyEnv is deliberately NOT included: an env var may be unset at
+// runtime while the profile actually relies on an OAuth login, so an
+// env-configured-but-empty profile must still be allowed to resolve a token.
+func (profile ProviderProfile) HasConfiguredCredential() bool {
+	return strings.TrimSpace(profile.APIKey) != "" ||
+		profile.APIKeyStored ||
+		strings.TrimSpace(profile.AuthHeaderValue) != ""
+}
+
+// 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.
+//
+// It returns NO candidates for a profile that carries its own configured
+// credential: attaching an OAuth resolver to such a profile makes withBearer
+// erase the key the instant a token resolves, silently routing/billing the call
+// through the OAuth account instead of the intended key (the cross-profile
+// override the review caught — and, via the profile name, a same-name login
+// overriding an explicit key). A stored-key profile that reaches this keyless
+// (e.g. a transiently unreadable keyring) is likewise treated as key-auth, so it
+// fails with a clear missing-credential error rather than silently borrowing an
+// unrelated OAuth login. APIKeyEnv is intentionally not part of that gate (an
+// env var may be unset while the profile relies on OAuth).
+//
+// For a keyless profile the profile name comes first (a login under your own
+// profile name is unambiguously yours), then the catalog ID as a FALLBACK (so a
+// profile renamed away from its catalog ID — e.g. {name:"codex",
+// catalogID:"chatgpt"} — still finds a `zero auth login chatgpt` token).
+// Candidates are trimmed, blank-skipped, and de-duplicated CASE-SENSITIVELY — the
+// OAuth token store is a case-sensitive map, so "ChatGPT" and "chatgpt" are
+// distinct keys and both must survive.
+func (profile ProviderProfile) OAuthLoginCandidates() []string {
+	if profile.HasConfiguredCredential() {
+		return nil
+	}
+	var names []string
+	add := func(s string) {
+		s = strings.TrimSpace(s)
+		if s == "" {
+			return
+		}
+		for _, existing := range names {
+			if existing == s { // case-sensitive: the store lookup is case-sensitive
+				return
+			}
+		}
+		names = append(names, s)
+	}
+	add(profile.Name)
+	add(profile.CatalogID)
+	return names
+}
+
 // ApplyStoredAPIKey fills profile.APIKey from the credential store when it is not
 // already resolved — an inline config key or a resolved APIKeyEnv always wins, so
 // this only supplies a key for providers whose secret lives in the store. A nil

internal/config/credentials_test.go

@@ -172,3 +172,69 @@ func TestProviderProfileAPIKeyStoredRoundTrips(t *testing.T) {
 		t.Fatalf("no inline key expected, got %q", p.APIKey)
 	}
 }
+
+// OAuthLoginCandidates always offers the profile name, adds the catalog ID as a
+// fallback ONLY when the profile has no effective own credential, and dedupes
+// case-sensitively (the OAuth store is a case-sensitive map).
+func TestOAuthLoginCandidates(t *testing.T) {
+	cases := []struct {
+		name    string
+		profile ProviderProfile
+		want    []string
+	}{
+		{
+			name:    "renamed keyless profile falls back to catalog id",
+			profile: ProviderProfile{Name: "codex", CatalogID: "chatgpt"},
+			want:    []string{"codex", "chatgpt"},
+		},
+		{
+			name:    "case-variant name keeps distinct catalog-id candidate",
+			profile: ProviderProfile{Name: "ChatGPT", CatalogID: "chatgpt"},
+			want:    []string{"ChatGPT", "chatgpt"},
+		},
+		{
+			name:    "exact-duplicate name and catalog id collapse",
+			profile: ProviderProfile{Name: "chatgpt", CatalogID: "chatgpt"},
+			want:    []string{"chatgpt"},
+		},
+		{
+			// A configured key must block ALL candidates (name included): a login
+			// under the profile's own name would otherwise erase the key too.
+			name:    "own inline key blocks every candidate",
+			profile: ProviderProfile{Name: "anthropic-work", CatalogID: "anthropic", APIKey: "sk-work"},
+			want:    nil,
+		},
+		{
+			name:    "own auth header blocks every candidate",
+			profile: ProviderProfile{Name: "acme", CatalogID: "anthropic", AuthHeaderValue: "Bearer x"},
+			want:    nil,
+		},
+		{
+			// APIKeyStored means key-auth even if the key isn't loaded here (e.g. a
+			// transiently unreadable keyring): don't silently borrow an OAuth login.
+			name:    "stored-key profile blocks every candidate",
+			profile: ProviderProfile{Name: "openai-stored", CatalogID: "openai", APIKeyStored: true},
+			want:    nil,
+		},
+		{
+			// APIKeyEnv is NOT a configured credential for gating: the env var may be
+			// unset while the profile relies on an OAuth login, so candidates stand.
+			name:    "env-only profile still yields candidates",
+			profile: ProviderProfile{Name: "xai", CatalogID: "xai", APIKeyEnv: "XAI_API_KEY"},
+			want:    []string{"xai"},
+		},
+		{
+			name:    "empty profile yields no candidates",
+			profile: ProviderProfile{},
+			want:    nil,
+		},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			got := c.profile.OAuthLoginCandidates()
+			if strings.Join(got, ",") != strings.Join(c.want, ",") {
+				t.Fatalf("OAuthLoginCandidates() = %#v, want %#v", got, c.want)
+			}
+		})
+	}
+}

internal/config/paths.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"runtime"
 	"strings"
 )
 
@@ -33,13 +34,32 @@ func DefaultResolveOptions(workspaceRoot string) (ResolveOptions, error) {
 }
 
 func DefaultUserConfigPath() (string, error) {
-	userConfigDir, err := os.UserConfigDir()
+	userConfigDir, err := UserConfigDir()
 	if err != nil {
 		return "", fmt.Errorf("resolve user config directory: %w", err)
 	}
 	return filepath.Join(userConfigDir, "zero", "config.json"), nil
 }
 
+// UserConfigDir returns the base directory Zero stores per-user config under.
+// It mirrors os.UserConfigDir everywhere except macOS: there Go defaults to
+// ~/Library/Application Support, but Zero deliberately uses ~/.config (XDG-style,
+// matching Linux and Claude Code) so a single config path works cross-platform.
+// $XDG_CONFIG_HOME still wins on macOS when set.
+func UserConfigDir() (string, error) {
+	if runtime.GOOS == "darwin" {
+		if xdg := strings.TrimSpace(os.Getenv("XDG_CONFIG_HOME")); xdg != "" {
+			return xdg, nil
+		}
+		home, err := os.UserHomeDir()
+		if err != nil {
+			return "", fmt.Errorf("resolve home directory: %w", err)
+		}
+		return filepath.Join(home, ".config"), nil
+	}
+	return os.UserConfigDir()
+}
+
 func existingConfigFile(path string) (string, error) {
 	info, err := os.Stat(path)
 	if err != nil {

internal/config/paths_test.go

@@ -105,7 +105,7 @@ func setUserConfigRoot(t *testing.T) string {
 		t.Setenv("XDG_CONFIG_HOME", root)
 	}
 
-	configRoot, err := os.UserConfigDir()
+	configRoot, err := UserConfigDir()
 	if err != nil {
 		t.Fatalf("UserConfigDir() error = %v", err)
 	}
@@ -130,3 +130,21 @@ func mkdirAll(t *testing.T, path string) {
 		t.Fatalf("create directory %s: %v", path, err)
 	}
 }
+
+func TestDefaultUserConfigPathUsesXDGConfigOnMacOS(t *testing.T) {
+	if runtime.GOOS != "darwin" {
+		t.Skip("macOS-specific config path behavior")
+	}
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	t.Setenv("XDG_CONFIG_HOME", "")
+
+	path, err := DefaultUserConfigPath()
+	if err != nil {
+		t.Fatalf("DefaultUserConfigPath() error = %v", err)
+	}
+	want := filepath.Join(home, ".config", "zero", "config.json")
+	if path != want {
+		t.Fatalf("DefaultUserConfigPath() = %q, want %q", path, want)
+	}
+}

internal/config/resolver.go

@@ -2,6 +2,7 @@ package config
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"net/url"
 	"os"
@@ -14,6 +15,31 @@ import (
 	"github.com/Gitlawb/zero/internal/sandbox"
 )
 
+// ErrNoActiveProvider marks a resolve failure caused solely by a missing or
+// unresolvable active provider. The interactive TUI treats this as "needs
+// onboarding" (drop into the setup wizard) rather than a fatal config error.
+var ErrNoActiveProvider = errors.New("no active provider configured")
+
+// ErrProviderRequiresModel marks a resolve failure caused solely by the active
+// provider missing a model with no catalog default to fall back on (custom
+// openai-/anthropic-compatible endpoints — Zero cannot guess a gateway's model).
+// Like ErrNoActiveProvider, the interactive TUI treats it as "needs onboarding"
+// and drops into the setup wizard so the user can fix it; headless commands
+// (zero config, zero exec) still fail with the actionable message.
+var ErrProviderRequiresModel = errors.New("provider requires model")
+
+// setupFixableError tags an error with a sentinel for errors.Is WITHOUT
+// changing its message: the sentinel's own text must not prefix what the user
+// sees (the wrapped message is already complete and actionable).
+type setupFixableError struct {
+	err      error
+	sentinel error
+}
+
+func (e *setupFixableError) Error() string { return e.err.Error() }
+
+func (e *setupFixableError) Unwrap() []error { return []error{e.err, e.sentinel} }
+
 // defaultMaxTurns is the per-run tool-turn budget when none is configured. 30 was
 // too low for real multi-step agentic work (agents ran out mid-task before reaching
 // later steps); 50 matches the old "deep" preset. Raise per-session with /turns.
@@ -370,6 +396,18 @@ func effectiveProviderKind(profile ProviderProfile) ProviderKind {
 	return ""
 }
 
+// catalogDefaultModel returns the default model of a catalog provider ("" when
+// the id is unknown), used to fill a missing profile.Model for the official-API
+// kinds so a hand-written profile without a model resolves instead of bricking
+// every command that resolves config up front (zero config, bare zero setup).
+func catalogDefaultModel(catalogID string) string {
+	descriptor, ok := providercatalog.Get(catalogID)
+	if !ok {
+		return ""
+	}
+	return strings.TrimSpace(descriptor.DefaultModel)
+}
+
 func catalogDescriptorForProfile(profile ProviderProfile) (providercatalog.Descriptor, bool) {
 	catalogID := providercatalog.NormalizeID(profile.CatalogID)
 	if catalogID == "" {
@@ -731,11 +769,16 @@ func unionStrings(base []string, extra []string) []string {
 }
 
 type normalizeOptions struct {
-	defaultOpenAIModel bool
+	// defaultModels fills a missing profile.Model for the official-API provider
+	// kinds (openai from the model registry; anthropic/google from their catalog
+	// descriptors). Off for provider-command configs (command.go), which must
+	// surface exactly what the external command returned rather than inventing
+	// a model behind its back.
+	defaultModels bool
 }
 
 func normalizeProviders(providers []ProviderProfile, activeName string, envMaps ...map[string]string) ([]ProviderProfile, ProviderProfile, error) {
-	return normalizeProvidersWithOptions(providers, activeName, normalizeOptions{defaultOpenAIModel: true}, envMaps...)
+	return normalizeProvidersWithOptions(providers, activeName, normalizeOptions{defaultModels: true}, envMaps...)
 }
 
 func normalizeProvidersWithoutModelDefaults(providers []ProviderProfile, activeName string, envMaps ...map[string]string) ([]ProviderProfile, ProviderProfile, error) {
@@ -750,7 +793,7 @@ func normalizeProvidersWithOptions(providers []ProviderProfile, activeName strin
 	}
 	if len(providers) == 0 {
 		if activeName != "" {
-			return nil, ProviderProfile{}, fmt.Errorf("active provider %q not found", activeName)
+			return nil, ProviderProfile{}, fmt.Errorf("%w: active provider %q not found", ErrNoActiveProvider, activeName)
 		}
 		return []ProviderProfile{}, ProviderProfile{}, nil
 	}
@@ -782,10 +825,13 @@ func normalizeProvidersWithOptions(providers []ProviderProfile, activeName strin
 	}
 
 	if !activeFound {
-		return nil, ProviderProfile{}, fmt.Errorf("active provider %q not found", activeName)
+		return nil, ProviderProfile{}, fmt.Errorf("%w: active provider %q not found", ErrNoActiveProvider, activeName)
 	}
 	if active.Model == "" {
-		return nil, ProviderProfile{}, providerError(active, "provider %s requires model", active.Name)
+		return nil, ProviderProfile{}, &setupFixableError{
+			err:      providerError(active, "provider %s requires model — add \"model\" to its entry in config.json, or re-run: zero setup <catalog-id> --model <model>", active.Name),
+			sentinel: ErrProviderRequiresModel,
+		}
 	}
 
 	return normalized, active, nil
@@ -832,7 +878,7 @@ func normalizeProvider(profile ProviderProfile, env map[string]string, options n
 	case ProviderKindOpenAI:
 		if profile.BaseURL == "" || isOfficialOpenAIBaseURL(profile.BaseURL) {
 			profile.BaseURL = OpenAIBaseURL
-			if options.defaultOpenAIModel && profile.Model == "" {
+			if options.defaultModels && profile.Model == "" {
 				profile.Model = modelregistry.DefaultModelID
 			}
 			return profile, nil
@@ -849,6 +895,9 @@ func normalizeProvider(profile ProviderProfile, env map[string]string, options n
 	case ProviderKindAnthropic:
 		if profile.BaseURL == "" || isOfficialAnthropicBaseURL(profile.BaseURL) {
 			profile.BaseURL = AnthropicBaseURL
+			if options.defaultModels && profile.Model == "" {
+				profile.Model = catalogDefaultModel("anthropic")
+			}
 			return profile, nil
 		}
 		return ProviderProfile{}, providerError(profile, "anthropic provider %s requires official baseURL %s", profile.Name, AnthropicBaseURL)
@@ -863,6 +912,9 @@ func normalizeProvider(profile ProviderProfile, env map[string]string, options n
 	case ProviderKindGoogle:
 		if profile.BaseURL == "" || isOfficialGoogleBaseURL(profile.BaseURL) {
 			profile.BaseURL = GoogleBaseURL
+			if options.defaultModels && profile.Model == "" {
+				profile.Model = catalogDefaultModel("google")
+			}
 			return profile, nil
 		}
 		return ProviderProfile{}, providerError(profile, "google provider %s requires official baseURL %s", profile.Name, GoogleBaseURL)

internal/config/resolver_test.go

@@ -1,6 +1,7 @@
 package config
 
 import (
+	"errors"
 	"os"
 	"path/filepath"
 	"reflect"
@@ -898,6 +899,9 @@ func TestResolveRejectsActiveProviderWithoutConfiguredProfiles(t *testing.T) {
 	if !strings.Contains(err.Error(), `active provider "ghost" not found`) {
 		t.Fatalf("error = %q, want active provider missing message", err.Error())
 	}
+	if !errors.Is(err, ErrNoActiveProvider) {
+		t.Fatalf("error = %v, want errors.Is(err, ErrNoActiveProvider)", err)
+	}
 	if resolved.ActiveProvider != "" {
 		t.Fatalf("ActiveProvider = %q, want empty", resolved.ActiveProvider)
 	}
@@ -1551,3 +1555,97 @@ func TestResolveMaxTurnsZeroFallsBackToDefault(t *testing.T) {
 		t.Fatalf("MaxTurns = %d, want default %d", resolved.MaxTurns, defaultMaxTurns)
 	}
 }
+
+// The reported brick: a hand-written google profile with an apiKey but no
+// model made EVERY resolving command fail ("provider google requires model"),
+// including zero config and bare zero setup — the only commands that could
+// have fixed it. Official-API kinds now fall back to their catalog default
+// model, exactly like the openai kind always has.
+func TestResolveDefaultsGoogleModelFromCatalog(t *testing.T) {
+	path := writeConfig(t, `{
+		"activeProvider": "google",
+		"providers": [{"name": "google", "provider_kind": "google", "apiKey": "AIza-x"}]
+	}`)
+	resolved, err := Resolve(ResolveOptions{UserConfigPath: path, Env: map[string]string{}})
+	if err != nil {
+		t.Fatalf("Resolve() error = %v, want model defaulted from the google catalog", err)
+	}
+	if resolved.Provider.Model != "gemini-2.5-pro" {
+		t.Fatalf("Model = %q, want the google catalog default gemini-2.5-pro", resolved.Provider.Model)
+	}
+	if resolved.Provider.BaseURL != GoogleBaseURL {
+		t.Fatalf("BaseURL = %q, want %q", resolved.Provider.BaseURL, GoogleBaseURL)
+	}
+}
+
+func TestResolveDefaultsAnthropicModelFromCatalog(t *testing.T) {
+	path := writeConfig(t, `{
+		"activeProvider": "anthropic",
+		"providers": [{"name": "anthropic", "provider_kind": "anthropic", "apiKey": "sk-ant-x"}]
+	}`)
+	resolved, err := Resolve(ResolveOptions{UserConfigPath: path, Env: map[string]string{}})
+	if err != nil {
+		t.Fatalf("Resolve() error = %v, want model defaulted from the anthropic catalog", err)
+	}
+	if resolved.Provider.Model != "claude-sonnet-4.5" {
+		t.Fatalf("Model = %q, want the anthropic catalog default claude-sonnet-4.5", resolved.Provider.Model)
+	}
+}
+
+// An explicitly configured model must always win over the catalog default.
+func TestResolveKeepsExplicitGoogleModel(t *testing.T) {
+	path := writeConfig(t, `{
+		"activeProvider": "google",
+		"providers": [{"name": "google", "provider_kind": "google", "apiKey": "AIza-x", "model": "gemini-2.5-flash"}]
+	}`)
+	resolved, err := Resolve(ResolveOptions{UserConfigPath: path, Env: map[string]string{}})
+	if err != nil {
+		t.Fatalf("Resolve() error = %v", err)
+	}
+	if resolved.Provider.Model != "gemini-2.5-flash" {
+		t.Fatalf("Model = %q, want the explicitly configured gemini-2.5-flash", resolved.Provider.Model)
+	}
+}
+
+// Provider-command configs must NOT get invented models: the without-defaults
+// path surfaces exactly what the external command returned.
+func TestNormalizeWithoutModelDefaultsStillRequiresGoogleModel(t *testing.T) {
+	_, _, err := normalizeProvidersWithoutModelDefaults(
+		[]ProviderProfile{{Name: "google", ProviderKind: ProviderKindGoogle, APIKey: "AIza-x"}},
+		"google", map[string]string{})
+	if err == nil {
+		t.Fatal("provider-command path must still require an explicit model")
+	}
+	if !strings.Contains(err.Error(), "requires model") {
+		t.Fatalf("error = %q, want requires-model", err.Error())
+	}
+	// The residual error must tell the user how to fix it.
+	if !strings.Contains(err.Error(), "config.json") {
+		t.Fatalf("error = %q, want an actionable config.json hint", err.Error())
+	}
+}
+
+// The residual requires-model failure (custom endpoint, no catalog default)
+// must be tagged setup-fixable WITHOUT changing its message: the interactive
+// TUI matches the sentinel to drop into the wizard, while headless commands
+// print the exact actionable text.
+func TestResolveRequiresModelErrorIsSetupFixable(t *testing.T) {
+	path := writeConfig(t, `{
+		"activeProvider": "gw",
+		"providers": [{"name": "gw", "provider_kind": "openai-compatible", "baseURL": "https://gw.example/v1", "apiKey": "sk-x"}]
+	}`)
+	_, err := Resolve(ResolveOptions{UserConfigPath: path, Env: map[string]string{}})
+	if err == nil {
+		t.Fatal("expected requires-model error for a custom endpoint without model")
+	}
+	if !errors.Is(err, ErrProviderRequiresModel) {
+		t.Fatalf("error = %v, want errors.Is(err, ErrProviderRequiresModel)", err)
+	}
+	// The sentinel must NOT prefix the user-facing message.
+	if !strings.HasPrefix(err.Error(), "provider gw requires model") {
+		t.Fatalf("message = %q, want it to start with the provider error, not the sentinel text", err.Error())
+	}
+	if strings.Contains(err.Error(), "sk-x") {
+		t.Fatalf("error leaked API key: %q", err.Error())
+	}
+}

internal/config/validate_test.go

@@ -66,10 +66,13 @@ func TestValidateFileRedactsSecretInIssue(t *testing.T) {
 }
 
 func TestValidateFileMissingModelWarns(t *testing.T) {
+	// An openai-compatible CUSTOM endpoint has no catalog default to fall back
+	// on, so a missing model is still a real issue — and the message must tell
+	// the user how to fix it.
 	path := writeValidateFixture(t, `{
 		"activeProvider": "main",
 		"providers": [
-			{"name": "main", "provider_kind": "anthropic"}
+			{"name": "main", "provider_kind": "openai-compatible", "baseURL": "https://gateway.example/v1"}
 		]
 	}`)
 
@@ -80,6 +83,30 @@ func TestValidateFileMissingModelWarns(t *testing.T) {
 	if !strings.Contains(issues[0].Message, "requires model") {
 		t.Fatalf("expected requires-model issue, got %#v", issues)
 	}
+	if !strings.Contains(issues[0].Message, "config.json") {
+		t.Fatalf("requires-model issue should carry an actionable hint, got %#v", issues)
+	}
+}
+
+func TestValidateFileDefaultsOfficialKindModels(t *testing.T) {
+	// Official-API kinds (anthropic/google) fall back to their catalog default
+	// model, so a hand-written model-less profile validates clean instead of
+	// bricking zero config / bare zero setup — the only commands that could
+	// have fixed it (the reported google case).
+	path := writeValidateFixture(t, `{
+		"activeProvider": "google",
+		"providers": [
+			{"name": "google", "provider_kind": "google", "apiKey": "AIza-x"},
+			{"name": "anthropic", "provider_kind": "anthropic", "apiKey": "sk-ant-x"}
+		]
+	}`)
+
+	_, issues := ValidateFile(path)
+	for _, issue := range issues {
+		if strings.Contains(issue.Message, "requires model") {
+			t.Fatalf("official-kind profiles must default their model, got issue %#v", issue)
+		}
+	}
 }
 
 func TestValidateFileValidConfigHasNoIssues(t *testing.T) {

internal/mcp/client_test.go

@@ -1,11 +1,11 @@
 package mcp
 
 import (
-	"bytes"
 	"context"
 	"encoding/json"
 	"errors"
 	"fmt"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"os"
@@ -393,28 +393,43 @@ func TestConnectRejectsUnsupportedTransport(t *testing.T) {
 }
 
 func TestClientRequestWaitsForMatchingResponseID(t *testing.T) {
-	var incoming bytes.Buffer
-	incomingWriter := newMessageWriter(&incoming)
-	if err := incomingWriter.write(rpcMessage{Method: "notifications/progress"}); err != nil {
-		t.Fatal(err)
-	}
-	if err := incomingWriter.write(rpcMessage{
-		ID:    99,
-		Error: &rpcError{Code: -32000, Message: "wrong response"},
-	}); err != nil {
-		t.Fatal(err)
-	}
-	if err := incomingWriter.write(rpcMessage{
-		ID:     1,
-		Result: mustRaw(map[string]any{"value": "matched"}),
-	}); err != nil {
-		t.Fatal(err)
-	}
+	// Pipes, not a pre-filled bytes.Buffer: the fake server responds only AFTER
+	// reading the outgoing request, matching production ordering. With responses
+	// pre-loaded, the client's reader goroutine could consume the matching
+	// response — and hit EOF — before request() registered its pending id,
+	// flaking as "request() error = EOF" on fast runners.
+	serverReader, clientWriter := io.Pipe() // client → server
+	clientReader, serverWriter := io.Pipe() // server → client
+	t.Cleanup(func() {
+		_ = clientWriter.Close()
+		_ = serverWriter.Close()
+	})
+
+	serverErr := make(chan error, 1)
+	go func() {
+		requests := newMessageReader(serverReader)
+		request, err := requests.read()
+		if err != nil {
+			serverErr <- err
+			return
+		}
+		responses := newMessageWriter(serverWriter)
+		for _, message := range []rpcMessage{
+			{Method: "notifications/progress"},
+			{ID: 99, Error: &rpcError{Code: -32000, Message: "wrong response"}},
+			{ID: request.ID, Result: mustRaw(map[string]any{"value": "matched"})},
+		} {
+			if err := responses.write(message); err != nil {
+				serverErr <- err
+				return
+			}
+		}
+		serverErr <- nil
+	}()
 
-	var outgoing bytes.Buffer
 	client := &Client{
-		reader: newMessageReader(&incoming),
-		writer: newMessageWriter(&outgoing),
+		reader: newMessageReader(clientReader),
+		writer: newMessageWriter(clientWriter),
 		nextID: 1,
 	}
 	var result struct {
@@ -426,6 +441,9 @@ func TestClientRequestWaitsForMatchingResponseID(t *testing.T) {
 	if result.Value != "matched" {
 		t.Fatalf("result.Value = %q, want matched response", result.Value)
 	}
+	if err := <-serverErr; err != nil {
+		t.Fatalf("fake server error: %v", err)
+	}
 }
 
 type errorCloser struct {

internal/oauth/store.go

@@ -41,6 +41,26 @@ func ValidateKey(key string) error {
 // ProviderKey builds the store key for a provider login.
 func ProviderKey(name string) string { return KeyPrefixProvider + 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
+// ProviderProfile.OAuthLoginCandidates() so that everything derived from a login
+// — the bearer token AND any header claim like chatgpt-account-id — comes from
+// the SAME login; selecting independently per consumer could otherwise pair a
+// bearer from one login with an account header from another. A load error on a
+// candidate is treated as a miss (skip to the next), never a hard failure.
+func FirstStored(store *Store, candidates []string) (Token, string, bool) {
+	if store == nil {
+		return Token{}, "", false
+	}
+	for _, name := range candidates {
+		key := ProviderKey(name)
+		if token, ok, err := store.Load(key); err == nil && ok {
+			return token, key, true
+		}
+	}
+	return Token{}, "", false
+}
+
 // Status is a redaction-safe summary of a stored token (no secret material).
 type Status struct {
 	Key             string    `json:"key"`

internal/providers/factory.go

@@ -26,6 +26,13 @@ type Options struct {
 	// OAuth bearer token (preferred over the API key). nil => API-key auth only.
 	// Applied to the OpenAI and Anthropic providers.
 	OAuthResolver providerio.TokenResolver
+	// OAuthLoginKey is the credential-store key OAuthResolver bound to (empty when
+	// there is no OAuth login). It is the SAME selection the bearer resolver made,
+	// resolved ONCE by the caller so the Codex chatgpt-account-id header reads its
+	// account from the exact login that issued the bearer token — never a second,
+	// independent lookup that could pick a different login (a backend-rejected
+	// mismatch).
+	OAuthLoginKey string
 }
 
 // New creates a runtime provider for a resolved provider profile.
@@ -251,14 +258,22 @@ func isCodexCatalog(profile config.ProviderProfile, _ resolvedProfile) bool {
 
 // newCodexProvider builds a Codex-flavored openai provider for the chatgpt
 // catalog. The Codex headers (`originator`, `chatgpt-account-id`) are
-// injected by the CodexProvider wrapper. The `chatgpt-account-id` is
-// resolved dynamically from the stored OAuth token's Account field on
-// every request so a refresh that rotates the token (and its account
-// claim) takes effect immediately — a static AccountID captured at
-// construction would go stale on the first refresh.
+// injected by the CodexProvider wrapper. The `chatgpt-account-id` is read from
+// the stored OAuth token's Account field on every request so a refresh that
+// rotates the token (and its account claim) takes effect immediately — a static
+// AccountID captured at construction would go stale on the first refresh.
+//
+// The *login* the header reads from is options.OAuthLoginKey — the SAME key the
+// bearer resolver bound, resolved ONCE by the caller. The bearer resolver
+// refreshes the token in place under that key; reading the account from the same
+// key keeps header and token on one login for the provider's life. Resolving the
+// key independently here (a second oauth.FirstStored) could, after a transient
+// per-candidate load error or a mid-session `zero auth login`, pick a different
+// login than the bearer — a mismatch the backend rejects.
 func newCodexProvider(profile config.ProviderProfile, resolved resolvedProfile, options Options) (zeroruntime.Provider, error) {
+	accountKey := options.OAuthLoginKey
 	resolver := openai.CodexAccountResolver(func(ctx context.Context) (string, bool, error) {
-		account := codexAccountFromStore(profile.Name)
+		account := codexAccountForKey(accountKey)
 		if account == "" {
 			return "", false, nil
 		}
@@ -288,17 +303,20 @@ func newCodexProvider(profile config.ProviderProfile, resolved resolvedProfile,
 	})
 }
 
-// codexAccountFromStore reads the chatgpt_account_id from the stored OAuth
-// token for the given provider name. It is called per-request (via the
-// resolver) so a refresh that rotates the token takes effect immediately
-// without restarting the agent. Returns "" when no token is stored (the
-// Codex provider then omits the header and the user sees a clear 401).
-func codexAccountFromStore(providerName string) string {
+// codexAccountForKey reads the chatgpt_account_id from the token currently
+// stored under key. Called per-request (via the resolver) so a refresh that
+// rotates the token — saved back in place under the same key — takes effect
+// immediately without restarting the agent. Returns "" when key is empty (no
+// OAuth login), or the token is absent or carries no account claim.
+func codexAccountForKey(key string) string {
+	if key == "" {
+		return ""
+	}
 	store, err := oauth.NewStore(oauth.StoreOptions{})
 	if err != nil {
 		return ""
 	}
-	token, ok, err := store.Load(oauth.ProviderKey(providerName))
+	token, ok, err := store.Load(key)
 	if err != nil || !ok {
 		return ""
 	}

internal/providers/factory_test.go

@@ -269,6 +269,7 @@ func TestNewRoutesChatGPTCatalogToCodexProvider(t *testing.T) {
 	// OAuth token and the "want empty chatgpt-account-id" assertion fails locally
 	// (it still passes in CI, where no login is stored). Mirrors the isolation in
 	// TestNewRoutesChatGPTCatalogWithStoredAccountID.
+	t.Setenv("ZERO_OAUTH_STORAGE", "file")
 	t.Setenv("ZERO_OAUTH_TOKENS_PATH", t.TempDir()+"/tokens.json")
 
 	transport := &captureTransport{
@@ -322,11 +323,10 @@ func TestNewRoutesChatGPTCatalogToCodexProvider(t *testing.T) {
 
 func TestNewRoutesChatGPTCatalogWithStoredAccountID(t *testing.T) {
 	// The factory reads the stored OAuth token's Account field for the
-	// chatgpt-account-id header. Seed a token in a temp store and point
-	// ZERO_OAUTH_TOKENS_PATH at it so the factory picks it up.
-	dir := t.TempDir()
-	t.Setenv("ZERO_OAUTH_TOKENS_PATH", dir+"/tokens.json")
-	store, err := newOAuthStoreForTest()
+	// chatgpt-account-id header, from the login key the CALLER supplies in
+	// Options.OAuthLoginKey (the same key the bearer resolver bound). Seed a
+	// token in an isolated temp store, then pass that key.
+	store, err := newOAuthStoreForTest(t)
 	if err != nil {
 		t.Fatalf("NewStore: %v", err)
 	}
@@ -344,8 +344,9 @@ func TestNewRoutesChatGPTCatalogWithStoredAccountID(t *testing.T) {
 		CatalogID: "chatgpt",
 		Model:     "gpt-5",
 	}, Options{
-		HTTPClient: &http.Client{Transport: transport},
-		UserAgent:  "zero-factory-test",
+		HTTPClient:    &http.Client{Transport: transport},
+		UserAgent:     "zero-factory-test",
+		OAuthLoginKey: oauth.ProviderKey("chatgpt"),
 	})
 	if err != nil {
 		t.Fatalf("New() error = %v", err)
@@ -407,10 +408,61 @@ func (transport *captureTransport) body() io.Reader {
 	return strings.NewReader(transport.requestBody)
 }
 
-// newOAuthStoreForTest builds a Store pointed at the current
-// ZERO_OAUTH_TOKENS_PATH (set by the caller). It exists so the chatgpt
-// factory tests can seed a token without copying the path-handling dance
-// from internal/cli.
-func newOAuthStoreForTest() (*oauth.Store, error) {
+// newOAuthStoreForTest pins the OAuth token store to a plain temp FILE and
+// returns a Store on it. Pinning ZERO_OAUTH_STORAGE matters as much as the
+// path: an inherited "keyring" value would send NewStore to the OS keychain
+// and ignore ZERO_OAUTH_TOKENS_PATH entirely, making the test read/write the
+// developer's real logins. Exists so the chatgpt factory tests can seed a
+// token without copying the path-handling dance from internal/cli.
+func newOAuthStoreForTest(t *testing.T) (*oauth.Store, error) {
+	t.Helper()
+	t.Setenv("ZERO_OAUTH_STORAGE", "file")
+	t.Setenv("ZERO_OAUTH_TOKENS_PATH", t.TempDir()+"/tokens.json")
 	return oauth.NewStore(oauth.StoreOptions{})
 }
+
+// codexAccountForKey reads the chatgpt-account-id from the token stored under a
+// FIXED key — the key the caller (cli.oauthLoginForProfile) already bound for the
+// bearer token, passed through providers.Options.OAuthLoginKey. The account is
+// therefore always read from the same login that issued the bearer (no second,
+// independent selection). It re-reads per call, so an in-place token refresh (new
+// account claim under the SAME key) is picked up; an empty key (no OAuth login)
+// or a missing/account-less token yields "".
+func TestCodexAccountForKey(t *testing.T) {
+	store, err := newOAuthStoreForTest(t)
+	if err != nil {
+		t.Fatalf("NewStore: %v", err)
+	}
+	if err := store.Save(oauth.ProviderKey("chatgpt"), oauth.Token{AccessToken: "tok-1", Account: "acc-catalog-7"}); err != nil {
+		t.Fatalf("Save chatgpt: %v", err)
+	}
+	// A different login WITHOUT an account claim, to prove the read stays on the
+	// requested key and never crosses to another login's account.
+	if err := store.Save(oauth.ProviderKey("codex"), oauth.Token{AccessToken: "tok-codex"}); err != nil {
+		t.Fatalf("Save codex: %v", err)
+	}
+
+	if got := codexAccountForKey(oauth.ProviderKey("chatgpt")); got != "acc-catalog-7" {
+		t.Fatalf("account = %q, want acc-catalog-7", got)
+	}
+	// The bound key's token has no account → "", NOT the other login's account.
+	if got := codexAccountForKey(oauth.ProviderKey("codex")); got != "" {
+		t.Fatalf("account = %q, want empty (must not cross to another login's account)", got)
+	}
+	// Empty key (no OAuth login) → header omitted.
+	if got := codexAccountForKey(""); got != "" {
+		t.Fatalf("account for empty key = %q, want empty", got)
+	}
+	// Unknown key → "".
+	if got := codexAccountForKey(oauth.ProviderKey("nope")); got != "" {
+		t.Fatalf("account for unknown key = %q, want empty", got)
+	}
+
+	// An in-place refresh under the bound key IS reflected per request.
+	if err := store.Save(oauth.ProviderKey("chatgpt"), oauth.Token{AccessToken: "tok-refreshed", Account: "acc-rotated"}); err != nil {
+		t.Fatalf("refresh chatgpt: %v", err)
+	}
+	if got := codexAccountForKey(oauth.ProviderKey("chatgpt")); got != "acc-rotated" {
+		t.Fatalf("account = %q, want acc-rotated (in-place refresh must be picked up)", got)
+	}
+}

internal/providers/gemini/provider.go

@@ -342,7 +342,7 @@ func (provider *Provider) geminiRequest(request zeroruntime.CompletionRequest) (
 			declarations = append(declarations, geminiFunctionDeclaration{
 				Name:        tool.Name,
 				Description: tool.Description,
-				Parameters:  tool.Parameters,
+				Parameters:  sanitizeGeminiSchema(tool.Parameters),
 			})
 		}
 		mapped.Tools = []geminiToolGroup{{FunctionDeclarations: declarations}}
@@ -350,6 +350,71 @@ func (provider *Provider) geminiRequest(request zeroruntime.CompletionRequest) (
 	return mapped, nil
 }
 
+// geminiSchemaFields is the subset of JSON Schema keywords Google's
+// functionDeclarations[].parameters accepts (the Generative AI Schema type).
+// Anything outside it — most notably OpenAI's `additionalProperties`, which Zero
+// emits on every tool's parameters and which Gemini 400s on ("Unknown name
+// \"additionalProperties\" … Cannot find field") — must be dropped before the
+// request goes out. Kept as an allowlist rather than a denylist so a schema
+// keyword Zero (or an MCP server) adds later can't silently leak an unsupported
+// field into the Gemini payload.
+var geminiSchemaFields = map[string]bool{
+	"type": true, "format": true, "title": true, "description": true,
+	"nullable": true, "enum": true, "items": true, "properties": true,
+	"required": true, "anyOf": true, "propertyOrdering": true, "default": true,
+	"minimum": true, "maximum": true, "minItems": true, "maxItems": true,
+	"minLength": true, "maxLength": true, "minProperties": true,
+	"maxProperties": true, "pattern": true, "example": true,
+}
+
+// sanitizeGeminiSchema returns a copy of a JSON-Schema map keeping only the
+// keywords Gemini supports (geminiSchemaFields), recursing through the nested
+// schemas under `properties`, `items`, and `anyOf`. Returns nil for a nil input
+// so a parameterless tool stays parameterless.
+func sanitizeGeminiSchema(schema map[string]any) map[string]any {
+	if schema == nil {
+		return nil
+	}
+	out := make(map[string]any, len(schema))
+	for key, value := range schema {
+		if !geminiSchemaFields[key] {
+			continue
+		}
+		switch key {
+		case "properties":
+			if props, ok := value.(map[string]any); ok {
+				cleaned := make(map[string]any, len(props))
+				for name, sub := range props {
+					if subMap, ok := sub.(map[string]any); ok {
+						cleaned[name] = sanitizeGeminiSchema(subMap)
+					} else {
+						cleaned[name] = sub
+					}
+				}
+				value = cleaned
+			}
+		case "items":
+			if subMap, ok := value.(map[string]any); ok {
+				value = sanitizeGeminiSchema(subMap)
+			}
+		case "anyOf":
+			if variants, ok := value.([]any); ok {
+				cleaned := make([]any, len(variants))
+				for i, variant := range variants {
+					if subMap, ok := variant.(map[string]any); ok {
+						cleaned[i] = sanitizeGeminiSchema(subMap)
+					} else {
+						cleaned[i] = variant
+					}
+				}
+				value = cleaned
+			}
+		}
+		out[key] = value
+	}
+	return out
+}
+
 func mapMessages(messages []zeroruntime.Message) (*geminiContent, []geminiContent, error) {
 	systemParts := []geminiPart{}
 	contents := []geminiContent{}

internal/providers/gemini/provider_test.go

@@ -3,6 +3,7 @@ package gemini
 import (
 	"context"
 	"encoding/json"
+	"fmt"
 	"net/http"
 	"net/http/httptest"
 	"reflect"
@@ -504,3 +505,129 @@ func eventsOfType(events []zeroruntime.StreamEvent, eventType zeroruntime.Stream
 	}
 	return matching
 }
+
+// TestSanitizeGeminiSchemaStripsUnsupportedFields: the sanitizer keeps only
+// Gemini-supported keywords and recurses into properties/items/anyOf, so no
+// OpenAI-ism (additionalProperties, $schema, patternProperties) survives at any
+// depth while legitimate fields (type/description/enum/required/default) stay.
+func TestSanitizeGeminiSchemaStripsUnsupportedFields(t *testing.T) {
+	in := map[string]any{
+		"type":                 "object",
+		"additionalProperties": false,
+		"$schema":              "https://json-schema.org/draft/2020-12/schema",
+		"required":             []string{"path"},
+		"properties": map[string]any{
+			"path": map[string]any{
+				"type":        "string",
+				"description": "a path",
+				"default":     ".",
+			},
+			"nested": map[string]any{
+				"type":                 "object",
+				"additionalProperties": false, // must be stripped at depth too
+				"properties": map[string]any{
+					"tags": map[string]any{
+						"type":  "array",
+						"items": map[string]any{"type": "string", "additionalProperties": true},
+					},
+				},
+			},
+		},
+	}
+	out := sanitizeGeminiSchema(in)
+
+	assertNoAdditionalProps(t, out, "root")
+	if out["additionalProperties"] != nil {
+		t.Fatal("top-level additionalProperties must be stripped")
+	}
+	if out["$schema"] != nil {
+		t.Fatal("$schema must be stripped")
+	}
+	// Legitimate fields survive.
+	if out["type"] != "object" {
+		t.Fatalf("type should survive, got %v", out["type"])
+	}
+	props := out["properties"].(map[string]any)
+	pathProp := props["path"].(map[string]any)
+	if pathProp["description"] != "a path" || pathProp["default"] != "." {
+		t.Fatalf("legitimate property fields must survive: %#v", pathProp)
+	}
+	// nil input stays nil (parameterless tool).
+	if sanitizeGeminiSchema(nil) != nil {
+		t.Fatal("nil schema should map to nil")
+	}
+}
+
+// assertNoAdditionalProps fails if additionalProperties appears anywhere in the
+// (recursively walked) schema.
+func assertNoAdditionalProps(t *testing.T, node any, path string) {
+	t.Helper()
+	switch v := node.(type) {
+	case map[string]any:
+		if _, ok := v["additionalProperties"]; ok {
+			t.Fatalf("additionalProperties leaked at %s", path)
+		}
+		for k, sub := range v {
+			assertNoAdditionalProps(t, sub, path+"."+k)
+		}
+	case []any:
+		for i, sub := range v {
+			assertNoAdditionalProps(t, sub, fmt.Sprintf("%s[%d]", path, i))
+		}
+	}
+}
+
+// TestGeminiRequestOmitsAdditionalPropertiesInToolSchema: end-to-end, the tool
+// parameters Zero emits (schemaToRuntimeMap always writes additionalProperties)
+// must not reach Gemini — otherwise every functionDeclaration is 400-rejected
+// ("Unknown name additionalProperties"), which broke all tool-using exec calls
+// against Google (issue #373).
+func TestGeminiRequestOmitsAdditionalPropertiesInToolSchema(t *testing.T) {
+	var gotBody map[string]any
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if err := json.NewDecoder(r.Body).Decode(&gotBody); err != nil {
+			t.Fatalf("decode request body: %v", err)
+		}
+		writeSSE(w, `{"usageMetadata":{"promptTokenCount":1}}`)
+	}))
+	defer server.Close()
+
+	provider, err := New(Options{APIKey: "k", BaseURL: server.URL + "/", Model: "models/gemini-2.5-flash"})
+	if err != nil {
+		t.Fatalf("New returned error: %v", err)
+	}
+	stream, err := provider.StreamCompletion(context.Background(), zeroruntime.CompletionRequest{
+		Messages: []zeroruntime.Message{{Role: zeroruntime.MessageRoleUser, Content: "hi"}},
+		Tools: []zeroruntime.ToolDefinition{{
+			Name:        "grep",
+			Description: "search",
+			Parameters: map[string]any{ // exactly what schemaToRuntimeMap produces
+				"type":                 "object",
+				"additionalProperties": false,
+				"required":             []string{"pattern"},
+				"properties": map[string]any{
+					"pattern": map[string]any{"type": "string", "description": "regex"},
+				},
+			},
+		}},
+	})
+	if err != nil {
+		t.Fatalf("StreamCompletion returned error: %v", err)
+	}
+	drain(stream)
+
+	tools := gotBody["tools"].([]any)
+	decls := tools[0].(map[string]any)["functionDeclarations"].([]any)
+	params := decls[0].(map[string]any)["parameters"].(map[string]any)
+	if _, ok := params["additionalProperties"]; ok {
+		t.Fatalf("additionalProperties must not be sent to Gemini: %#v", params)
+	}
+	// The tool is still usable: its real schema survived.
+	if params["type"] != "object" {
+		t.Fatalf("tool parameters type should survive, got %v", params["type"])
+	}
+	props := params["properties"].(map[string]any)
+	if _, ok := props["pattern"]; !ok {
+		t.Fatalf("tool property must survive sanitization: %#v", props)
+	}
+}

internal/specialist/manifest.go

@@ -11,6 +11,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/Gitlawb/zero/internal/config"
 	"github.com/Gitlawb/zero/internal/modelregistry"
 )
 
@@ -120,7 +121,7 @@ var knownToolNames = map[string]bool{
 }
 
 func DefaultPaths(workspaceRoot string) (Paths, error) {
-	userConfigDir, err := os.UserConfigDir()
+	userConfigDir, err := config.UserConfigDir()
 	if err != nil {
 		return Paths{}, fmt.Errorf("resolve user config directory: %w", err)
 	}

internal/tui/command_views.go

@@ -467,7 +467,7 @@ func providerNextActionLines(profile config.ProviderProfile, snapshot zerocomman
 }
 
 func providerProfileHasCredential(profile config.ProviderProfile) bool {
-	return strings.TrimSpace(profile.APIKey) != "" || profile.APIKeyStored || strings.TrimSpace(profile.AuthHeaderValue) != ""
+	return profile.HasConfiguredCredential()
 }
 
 func providerCredentialRequired(profile config.ProviderProfile, providerKind string) bool {

internal/tui/model.go

@@ -635,7 +635,7 @@ func newModel(ctx context.Context, options Options) model {
 		}
 	}
 
-	userConfigDir, _ := os.UserConfigDir()
+	userConfigDir, _ := config.UserConfigDir()
 	loadedUserCommands := usercommands.Load(usercommands.DefaultPaths(cwd, userConfigDir))
 
 	registry := options.Registry

internal/tui/onboarding.go

@@ -755,6 +755,15 @@ func (m model) completeSetup() (tea.Model, tea.Cmd) {
 		m.providerProfile = result.Provider
 		m.providerName = result.Provider.Name
 		m.modelName = result.Provider.Model
+		// Export ZERO_PROVIDER alongside the committed profile fields (and the
+		// config setupSave already persisted as active). Unlike command_center's
+		// switch — which commits everything only after a successful build — setup
+		// commits config + profile unconditionally here, so the env must match
+		// them unconditionally too: applyEnv makes ZERO_PROVIDER WIN over config,
+		// so a stale value from an earlier /model switch left in place would send
+		// spawned children to the OLD provider even though config now names the
+		// new one. That is the exact D3 gap this closes.
+		config.SetActiveProviderEnv(result.Provider.Name)
 		if m.newProvider != nil {
 			if provider, providerErr := m.newProvider(result.Provider); providerErr == nil {
 				m.provider = provider

internal/tui/onboarding_test.go

@@ -3,6 +3,7 @@ package tui
 import (
 	"context"
 	"errors"
+	"os"
 	"strings"
 	"testing"
 
@@ -1535,3 +1536,42 @@ func absInt(value int) int {
 	}
 	return value
 }
+
+// Completing setup switches the live provider, so it must export ZERO_PROVIDER
+// exactly like the /model, /provider, and wizard switch paths — a stale value
+// from an earlier switch would otherwise win over config in every spawned
+// child (applyEnv) and pin specialists/swarm members to the OLD provider's
+// credentials.
+func TestCompleteSetupExportsActiveProviderEnv(t *testing.T) {
+	t.Setenv(config.ActiveProviderEnv, "stale-previous-provider")
+	m := newModel(context.Background(), Options{
+		Setup: SetupOptions{
+			Visible: true,
+			Providers: []SetupProviderOption{
+				{ID: "openai", Name: "OpenAI", DefaultModel: "gpt-4.1", EnvVar: "OPENAI_API_KEY", RequiresAuth: true},
+			},
+			Save: func(selection SetupSelection) (SetupResult, error) {
+				return SetupResult{
+					Provider: config.ProviderProfile{
+						Name:      selection.CatalogID,
+						CatalogID: selection.CatalogID,
+						Model:     selection.Model,
+					},
+				}, nil
+			},
+		},
+	})
+	m.width = 100
+	m.height = 30
+	m.setup.stage = setupStageReady
+
+	updated, _ := m.completeSetup()
+	next := updated.(model)
+
+	if next.providerName == "" {
+		t.Fatal("setup completion should have set a provider name")
+	}
+	if got := os.Getenv(config.ActiveProviderEnv); got != next.providerName {
+		t.Fatalf("%s = %q after setup save, want %q (children would spawn on the stale provider)", config.ActiveProviderEnv, got, next.providerName)
+	}
+}

internal/tui/provider_wizard.go

@@ -20,6 +20,7 @@ import (
 	"github.com/Gitlawb/zero/internal/providercatalog"
 	"github.com/Gitlawb/zero/internal/provideroauth"
 	"github.com/Gitlawb/zero/internal/redaction"
+	"github.com/Gitlawb/zero/internal/zeroruntime"
 )
 
 // providerWizardOAuthMsg carries the result of an in-wizard browser OAuth login.
@@ -887,13 +888,20 @@ func (m model) applyProviderWizard() (model, tea.Cmd) {
 	modelChoice := wizard.currentModel()
 	profile := providerWizardProfile(provider, modelChoice.ID, wizard.apiKey, wizard.baseURL, wizard.profileName)
 	runtimeProfile := providerWizardRuntimeProfile(profile)
+
+	// Build and persist into LOCALS first, committing live state only once BOTH
+	// succeed. A persist failure (read-only config, disk full) must not leave the
+	// chat running on the new provider while the status line, m.providerProfile,
+	// and the ZERO_PROVIDER export (which pins spawned children) still point at
+	// the old one — parent and children would silently run on different providers.
+	var nextProvider zeroruntime.Provider
 	if m.newProvider != nil {
-		nextProvider, err := m.newProvider(runtimeProfile)
+		built, err := m.newProvider(runtimeProfile)
 		if err != nil {
 			wizard.err = redaction.RedactString(err.Error(), redaction.Options{ExtraSecretValues: []string{profile.APIKey, runtimeProfile.APIKey}})
 			return m, nil
 		}
-		m.provider = nextProvider
+		nextProvider = built
 	}
 	if strings.TrimSpace(m.userConfigPath) != "" {
 		// Capture flip: move the freshly entered key into the encrypted credential
@@ -903,12 +911,24 @@ func (m model) applyProviderWizard() (model, tea.Cmd) {
 		profile = config.SecureProviderProfile(profile, m.userConfigPath)
 		if _, err := config.UpsertProvider(m.userConfigPath, profile, true); err != nil {
 			wizard.err = redaction.RedactString(err.Error(), redaction.Options{ExtraSecretValues: []string{secret, profile.APIKey}})
-			return m, nil
+			return m, nil // nothing committed to live state yet
 		}
 	}
+
+	// Both succeeded — commit the live provider, profile, model, and the child
+	// env export together, so they can never disagree.
+	if nextProvider != nil {
+		m.provider = nextProvider
+	}
 	m.providerProfile = profile
 	m.providerName = profile.Name
 	m.modelName = profile.Model
+	// Keep sub-agent child processes on the same provider we just switched to —
+	// same as the /model and /provider switch paths (command_center.go). Without
+	// this, a ZERO_PROVIDER exported by an earlier switch stays pointing at the
+	// OLD provider and wins over config in every spawned child (applyEnv), so
+	// specialists/swarm members run on the wrong provider's credentials.
+	config.SetActiveProviderEnv(profile.Name)
 	m.providerWizard = nil
 	return m, nil
 }

internal/tui/provider_wizard_test.go

@@ -1189,3 +1189,104 @@ func containsString(values []string, want string) bool {
 	}
 	return false
 }
+
+// Applying the wizard switches the live provider, so it must export
+// ZERO_PROVIDER exactly like the /model and /provider switch paths — a stale
+// value from an earlier switch would otherwise win over config in every
+// spawned child (applyEnv) and pin specialists/swarm members to the OLD
+// provider's credentials.
+func TestApplyProviderWizardExportsActiveProviderEnv(t *testing.T) {
+	t.Setenv(config.ActiveProviderEnv, "stale-previous-provider")
+	m := newModel(context.Background(), Options{})
+	// Isolate the SUCCESS path's persist to a temp config (the default empty
+	// path would skip persist; a future default must never reach the real user
+	// config), and stub the build so the full commit sequence runs.
+	m.userConfigPath = filepath.Join(t.TempDir(), "config.json")
+	m.newProvider = func(config.ProviderProfile) (zeroruntime.Provider, error) {
+		return &fakeProvider{}, nil
+	}
+	m.providerWizard = &providerWizardState{
+		step:        providerWizardStepModel,
+		profileName: "acme-wizard",
+		providers: []providercatalog.Descriptor{{
+			ID:                  "openrouter",
+			Name:                "OpenRouter",
+			Transport:           providercatalog.TransportOpenAICompatible,
+			DefaultBaseURL:      "https://openrouter.ai/api/v1",
+			DefaultModel:        "openai/gpt-4.1",
+			AuthEnvVars:         []string{"OPENROUTER_API_KEY"},
+			RequiresAuth:        true,
+			SupportedAPIFormats: []providercatalog.APIFormat{providercatalog.APIFormatOpenAIChatCompletions},
+		}},
+		models: []providerWizardModel{{ID: "openai/gpt-4.1", Description: "GPT-4.1"}},
+	}
+
+	updated, _ := m.applyProviderWizard()
+	next := updated
+
+	if next.providerName == "" {
+		t.Fatal("wizard apply should have set a provider name")
+	}
+	if got := os.Getenv(config.ActiveProviderEnv); got != next.providerName {
+		t.Fatalf("%s = %q after wizard apply, want %q (children would spawn on the stale provider)", config.ActiveProviderEnv, got, next.providerName)
+	}
+}
+
+// On a config PERSIST failure, applyProviderWizard must leave live state fully
+// unchanged — the chat must NOT already be running on the new provider while the
+// status line and the ZERO_PROVIDER export (which pins spawned children) still
+// point at the old one. Build and persist are staged into locals; nothing is
+// committed unless both succeed.
+func TestApplyProviderWizardPersistFailureLeavesLiveStateUnchanged(t *testing.T) {
+	t.Setenv("ZERO_CRED_STORAGE", "encrypted-file") // never touch the real OS keychain: apiKey is secured before the persist fails
+	t.Setenv(config.ActiveProviderEnv, "old-provider")
+
+	// A config path whose parent is a regular FILE, so writeConfigFile's MkdirAll
+	// fails and UpsertProvider returns an error.
+	blocker := filepath.Join(t.TempDir(), "not-a-dir")
+	if err := os.WriteFile(blocker, []byte("x"), 0o600); err != nil {
+		t.Fatalf("seed blocker file: %v", err)
+	}
+	brokenConfigPath := filepath.Join(blocker, "config.json")
+
+	oldProvider := &fakeProvider{}
+	newProvider := &fakeProvider{}
+	m := newModel(context.Background(), Options{})
+	m.provider = oldProvider
+	m.providerProfile = config.ProviderProfile{Name: "old-provider"}
+	m.providerName = "old-provider"
+	m.userConfigPath = brokenConfigPath
+	m.newProvider = func(config.ProviderProfile) (zeroruntime.Provider, error) { return newProvider, nil }
+	m.providerWizard = &providerWizardState{
+		step:        providerWizardStepModel,
+		profileName: "acme-new",
+		providers: []providercatalog.Descriptor{{
+			ID:                  "openrouter",
+			Name:                "OpenRouter",
+			Transport:           providercatalog.TransportOpenAICompatible,
+			DefaultBaseURL:      "https://openrouter.ai/api/v1",
+			DefaultModel:        "openai/gpt-4.1",
+			AuthEnvVars:         []string{"OPENROUTER_API_KEY"},
+			RequiresAuth:        true,
+			SupportedAPIFormats: []providercatalog.APIFormat{providercatalog.APIFormatOpenAIChatCompletions},
+		}},
+		models: []providerWizardModel{{ID: "openai/gpt-4.1", Description: "GPT-4.1"}},
+		apiKey: "sk-new",
+	}
+
+	updated, _ := m.applyProviderWizard()
+	next := updated
+
+	if next.providerWizard == nil || next.providerWizard.err == "" {
+		t.Fatal("a persist failure must surface a wizard error and keep the wizard open")
+	}
+	if next.provider != oldProvider {
+		t.Fatal("live provider must NOT be swapped when the persist fails")
+	}
+	if next.providerName != "old-provider" {
+		t.Fatalf("providerName = %q, want it unchanged on persist failure", next.providerName)
+	}
+	if got := os.Getenv(config.ActiveProviderEnv); got != "old-provider" {
+		t.Fatalf("%s = %q, want it unchanged on persist failure (children would diverge from parent)", config.ActiveProviderEnv, got)
+	}
+}

release-please-config.json

@@ -0,0 +1,11 @@
+{
+  "$schema": "https://raw.githubusercontent.com/googleapis/release-please/main/schemas/config.json",
+  "release-type": "node",
+  "include-component-in-tag": false,
+  "bootstrap-sha": "02f0c0929bec65f5fc41bdcab3eb518d2b0b329a",
+  "packages": {
+    ".": {
+      "package-name": "@gitlawb/zero"
+    }
+  }
+}