test: isolate OAuth/config test storage and fix the flaky MCP response-id test

Review + CI fixes, all test-only:

- factory/cli OAuth tests: pin ZERO_OAUTH_STORAGE=file next to the temp
  ZERO_OAUTH_TOKENS_PATH — an inherited "keyring" value sends NewStore to
  the OS keychain and ignores the temp path entirely, so the tests could
  read (or clobber) the developer's real logins. newOAuthStoreForTest now
  owns both pins so a future call site can't forget them.
- TestApplyProviderWizardExportsActiveProviderEnv: point m.userConfigPath
  at a temp config and stub newProvider, so the SUCCESS path exercises the
  full build+persist+commit sequence in isolation (the default empty path
  silently skipped persist; a changed default must never reach the real
  user config).
- TestClientRequestWaitsForMatchingResponseID (ubuntu smoke flake): the
  responses were pre-loaded into a bytes.Buffer, so the client's reader
  goroutine could consume the matching response — and hit EOF — before
  request() registered its pending id, failing with "request() error =
  EOF" on fast runners. The fake server now sits on pipes and responds
  only after reading the outgoing request, matching production ordering;
  survives -race -count=50.

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,
@@ -493,6 +504,17 @@ 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
 }
 
@@ -720,20 +742,50 @@ 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/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/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/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/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/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)
+	}
+}