feat(settings): KI-provider — OpenAI key field, model preset dropdown, gated OAuth

Bucket C of the v1.4.3 polish pass.

Three independent bugs in the KI-provider settings, fixed together
because they all live on the same panel:

1. **Selecting "OpenAI" left no way to provide a key.** The schema
   stored Anthropic and Local API keys, but OPENAI was a valid
   `aiProvider` value with no matching credential column — the
   resolver silently fell through to the admin-level OpenAI key. So
   a self-hosted user who picked OpenAI and typed nothing got the
   admin's key (might not exist), and a user who *wanted* their own
   OpenAI key had no UI surface to enter it.

   Migration `0026_user_ai_openai_key` adds `users.ai_openai_key_
   encrypted`. The resolver's `OPENAI` branch now picks up the
   user-level key first and only falls back to admin if the user
   slot is empty. The settings UI grew an OpenAI-key field gated on
   `provider === "OPENAI"` mirroring the Anthropic flow. The
   `/api/ai/test` override schema accepts `openaiKey` so the
   "Verbindung testen" button can validate an unsaved key without
   persisting plaintext.

2. **Model field was a freetext Input, easy to typo.** Replaced
   with a `<select>` populated from `MODEL_PRESETS` per provider:
   gpt-4o / gpt-4o-mini / gpt-4-turbo / gpt-5 / o3-mini for OPENAI;
   claude-sonnet-4-6 / claude-opus-4-7 / claude-haiku-4-5 / claude-
   3-5-sonnet-latest for ANTHROPIC; llama3.1:8b / llama3.1:70b /
   mistral / qwen2.5 for LOCAL. An "Eigenes…" sentinel still
   surfaces the freetext Input so power users can target preview
   models or fine-tunes. The dropdown disables when no provider is
   chosen — saves the user from filling a model that won't be used.

3. **"Mit ChatGPT verbinden" silently bounced to chatgpt.com login
   with no OAuth grant.** The authorize URL was built without a
   `client_id` parameter, so chatgpt.com couldn't recognise the
   request as an OAuth handshake — it just rendered the regular
   login form. The user came back, nothing connected, the button
   "did nothing".

   Added `CODEX_OAUTH_CLIENT_ID` env var. The URL builder now
   throws `CodexOAuthNotConfiguredError` if it's unset; the
   authorize route maps that to a 503 with an actionable message
   instead of dispatching the dead URL. The settings card reads
   `codexOauthConfigured` from `/api/insights/settings` and hides
   the Connect button when the flag is false, replacing it with a
   tiny italicised "ChatGPT-OAuth ist auf dieser Instanz nicht
   konfiguriert — nutze stattdessen einen eigenen API-Key unten."
   `CHATGPT_OAUTH` was also removed as a manually-selectable
   provider option in the dropdown — the top connect button is the
   path; having both confused the affordance.

Refresh + token-exchange both forward the client_id now too. Test
fixture seeds `process.env.CODEX_OAUTH_CLIENT_ID="test_client_id"`
in `beforeEach` so the existing URL-shape assertion still works,
plus a new test asserts the unset case throws.

Tests + typecheck green (670/670 — one new assertion).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

prisma/migrations/0026_user_ai_openai_key/migration.sql

@@ -0,0 +1,14 @@
+-- v1.4.3: per-user OpenAI API key.
+--
+-- Until this release the schema stored Anthropic and Local-provider API
+-- keys but no field for the OPENAI provider, even though OPENAI was a
+-- valid value in `users.ai_provider`. Users who picked it had no place
+-- in the UI to drop their key and the runtime fell through to whichever
+-- admin-level fallback was configured. This column is the missing slot.
+--
+-- AES-256-GCM encrypted at the application layer (`src/lib/crypto.ts`)
+-- before the value lands on disk. Plaintext keys never touch Postgres
+-- backups.
+
+ALTER TABLE "users"
+  ADD COLUMN "ai_openai_key_encrypted" TEXT;

prisma/schema.prisma

@@ -70,6 +70,11 @@ model User {
   aiBaseUrl String? @map("ai_base_url")
   aiAnthropicKeyEncrypted String? @map("ai_anthropic_key_encrypted")
   aiLocalKeyEncrypted String? @map("ai_local_key_encrypted")
+  // v1.4.3: per-user OpenAI API key for the OPENAI provider — previously
+  // the schema only stored Anthropic and Local keys, leaving OPENAI without
+  // a credential surface. Encrypted with the active ENCRYPTION_KEYS entry
+  // before storage.
+  aiOpenaiKeyEncrypted String? @map("ai_openai_key_encrypted")
 
   // Onboarding
   onboardingCompletedAt DateTime? @map("onboarding_completed_at")

src/app/api/ai/test/route.ts

@@ -22,6 +22,7 @@ const overrideSchema = z
     baseUrl: z.string().url().max(2048).optional().nullable(),
     anthropicKey: z.string().min(1).max(500).optional().nullable(),
     localKey: z.string().min(1).max(500).optional().nullable(),
+    openaiKey: z.string().min(1).max(500).optional().nullable(),
   })
   .strict();
 

src/app/api/auth/codex/authorize/route.ts

@@ -5,6 +5,8 @@ import {
   generatePKCE,
   generateState,
   buildAuthorizationUrl,
+  CodexOAuthNotConfiguredError,
+  isCodexOAuthConfigured,
 } from "@/lib/ai/codex-oauth";
 import { cookies } from "next/headers";
 import { annotate } from "@/lib/logging/context";
@@ -12,6 +14,17 @@ import { annotate } from "@/lib/logging/context";
 export const GET = apiHandler(async (_request: NextRequest) => {
   const { user } = await requireAuth();
 
+  // Surface configuration errors as 503 instead of silently redirecting
+  // to a dead chatgpt.com URL. The v1.4.2 build dropped the `client_id`
+  // out of the authorize URL — the user landed on the chatgpt.com login
+  // page, no callback ever fired, and the connect button "did nothing".
+  if (!isCodexOAuthConfigured()) {
+    throw new HttpError(
+      503,
+      "Codex OAuth is not configured on this instance — set CODEX_OAUTH_CLIENT_ID",
+    );
+  }
+
   const rl = await checkRateLimit(`codex-authorize:${user.id}`, 5, 60_000);
   if (!rl.allowed) throw new HttpError(429, "Too many requests");
 
@@ -35,11 +48,21 @@ export const GET = apiHandler(async (_request: NextRequest) => {
   cookieStore.set("codex_verifier", verifier, cookieOptions);
   cookieStore.set("codex_state", state, cookieOptions);
 
-  const authUrl = buildAuthorizationUrl({
-    codeChallenge: challenge,
-    state,
-    redirectUri,
-  });
+  let authUrl: string;
+  try {
+    authUrl = buildAuthorizationUrl({
+      codeChallenge: challenge,
+      state,
+      redirectUri,
+    });
+  } catch (err) {
+    // Race between the env check above and the URL build — extremely
+    // unlikely but the typed error path is cheap insurance.
+    if (err instanceof CodexOAuthNotConfiguredError) {
+      throw new HttpError(503, err.message);
+    }
+    throw err;
+  }
   annotate({ action: { name: "codex.oauth.authorize" } });
 
   return NextResponse.redirect(authUrl);

src/app/api/insights/settings/route.ts

@@ -3,6 +3,7 @@ import { apiSuccess, apiError, safeJson } from "@/lib/api-response";
 import { NextRequest } from "next/server";
 import { apiHandler, requireAuth } from "@/lib/api-handler";
 import { annotate } from "@/lib/logging/context";
+import { isCodexOAuthConfigured } from "@/lib/ai/codex-oauth";
 
 export const GET = apiHandler(async () => {
   const { user } = await requireAuth();
@@ -28,6 +29,11 @@ export const GET = apiHandler(async () => {
     codexStatus: dbUser?.codexConnectionStatus ?? "disconnected",
     codexConnectedAt: dbUser?.codexConnectedAt ?? null,
     hasAdminKey: !!settings?.adminAiKeyEncrypted,
+    // v1.4.3: surface whether the operator has a `CODEX_OAUTH_CLIENT_ID`
+    // configured. Without it the Connect-with-ChatGPT flow is dead, so
+    // the UI hides the button instead of redirecting to a chatgpt.com
+    // login the user can never complete.
+    codexOauthConfigured: isCodexOAuthConfigured(),
     privacyMode: dbUser?.insightsPrivacyMode ?? "aggregated",
     lastInsightAt: dbUser?.insightsCachedAt ?? null,
   });

src/app/api/user/ai-provider/route.ts

@@ -22,6 +22,7 @@ export const GET = apiHandler(async () => {
       aiBaseUrl: true,
       aiAnthropicKeyEncrypted: true,
       aiLocalKeyEncrypted: true,
+      aiOpenaiKeyEncrypted: true,
     },
   });
 
@@ -34,6 +35,10 @@ export const GET = apiHandler(async () => {
       ? `...${decrypt(u.aiAnthropicKeyEncrypted).slice(-4)}`
       : null,
     hasLocalKey: Boolean(u?.aiLocalKeyEncrypted),
+    hasOpenaiKey: Boolean(u?.aiOpenaiKeyEncrypted),
+    openaiKeyPreview: u?.aiOpenaiKeyEncrypted
+      ? `...${decrypt(u.aiOpenaiKeyEncrypted).slice(-4)}`
+      : null,
   });
 });
 
@@ -100,6 +105,14 @@ export const PATCH = apiHandler(async (request: NextRequest) => {
     }
   }
 
+  if (body.openaiKey !== undefined) {
+    if (body.openaiKey === null || body.openaiKey === "") {
+      updates.aiOpenaiKeyEncrypted = null;
+    } else if (typeof body.openaiKey === "string") {
+      updates.aiOpenaiKeyEncrypted = encrypt(body.openaiKey.trim());
+    }
+  }
+
   if (Object.keys(updates).length === 0) {
     throw new HttpError(422, "No valid fields");
   }

src/components/settings/ai-section.tsx

@@ -18,6 +18,11 @@ interface InsightsSettings {
   codexStatus: string;
   codexConnectedAt: string | null;
   hasAdminKey: boolean;
+  /** True when the operator has set `CODEX_OAUTH_CLIENT_ID` on this
+   *  instance. The UI hides the "Connect with ChatGPT" button when
+   *  false to avoid the v1.4.2 dead-end where the click bounced the
+   *  user to chatgpt.com without any OAuth flow. */
+  codexOauthConfigured?: boolean;
   privacyMode: string;
   lastInsightAt: string | null;
 }
@@ -29,8 +34,30 @@ interface UserAIProvider {
   hasAnthropicKey: boolean;
   anthropicKeyPreview: string | null;
   hasLocalKey: boolean;
+  hasOpenaiKey: boolean;
+  openaiKeyPreview: string | null;
 }
 
+/**
+ * Model presets per provider — keeps users out of the freetext box for
+ * the common case and signals which models the resolver will actually
+ * use as defaults if the field is left blank. The `__custom__` sentinel
+ * surfaces a freetext Input so power users can still target any model
+ * the underlying API speaks (e.g. preview models, fine-tunes).
+ */
+const MODEL_PRESETS: Record<string, ReadonlyArray<string>> = {
+  OPENAI: ["gpt-4o", "gpt-4o-mini", "gpt-4-turbo", "gpt-5", "o3-mini"],
+  ANTHROPIC: [
+    "claude-sonnet-4-6",
+    "claude-opus-4-7",
+    "claude-haiku-4-5",
+    "claude-3-5-sonnet-latest",
+  ],
+  LOCAL: ["llama3.1:8b", "llama3.1:70b", "mistral", "qwen2.5"],
+};
+
+const CUSTOM_MODEL_SENTINEL = "__custom__";
+
 export function AiSection() {
   const { t } = useTranslations();
   const { isAuthenticated } = useAuth();
@@ -275,14 +302,21 @@ function InsightsSettingsCard({
                   Leitlinien zu erhalten. Keine zusätzlichen API-Kosten.
                 </p>
               </div>
-              <Button
-                variant="outline"
-                onClick={handleConnect}
-                className="w-full sm:w-auto"
-              >
-                <Sparkles className="mr-2 h-4 w-4" />
-                Mit ChatGPT verbinden
-              </Button>
+              {settings?.codexOauthConfigured ? (
+                <Button
+                  variant="outline"
+                  onClick={handleConnect}
+                  className="w-full sm:w-auto"
+                >
+                  <Sparkles className="mr-2 h-4 w-4" />
+                  Mit ChatGPT verbinden
+                </Button>
+              ) : (
+                <p className="text-muted-foreground text-xs italic">
+                  ChatGPT-OAuth ist auf dieser Instanz nicht konfiguriert —
+                  nutze stattdessen einen eigenen API-Key unten.
+                </p>
+              )}
               {settings?.hasAdminKey && (
                 <p className="text-muted-foreground text-xs">
                   Alternativ nutzt HealthLog den vom Administrator
@@ -353,10 +387,12 @@ function InsightsSettingsCard({
 function UserAIProviderSubsection() {
   const queryClient = useQueryClient();
   const [provider, setProvider] = useState<string>("");
-  const [model, setModel] = useState<string>("");
+  const [modelChoice, setModelChoice] = useState<string>("");
+  const [customModel, setCustomModel] = useState<string>("");
   const [baseUrl, setBaseUrl] = useState<string>("");
   const [anthropicKey, setAnthropicKey] = useState<string>("");
   const [localKey, setLocalKey] = useState<string>("");
+  const [openaiKey, setOpenaiKey] = useState<string>("");
   const [saveMsg, setSaveMsg] = useState<string | null>(null);
   const [saveOk, setSaveOk] = useState<boolean>(false);
   const [testMsg, setTestMsg] = useState<string | null>(null);
@@ -374,26 +410,57 @@ function UserAIProviderSubsection() {
   });
 
   // React-recommended sync-from-server pattern (no setState-in-effect).
+  // The model dropdown reflects the saved value: an exact match against
+  // the preset list selects that preset; anything else (or the empty
+  // "use default" string) collapses to the custom-input mode so the
+  // user keeps full control.
   const dataKey = data
     ? `${data.provider ?? ""}|${data.model ?? ""}|${data.baseUrl ?? ""}`
     : null;
   const [seededKey, setSeededKey] = useState<string | null>(null);
   if (dataKey && dataKey !== seededKey) {
     setSeededKey(dataKey);
-    setProvider(data!.provider ?? "");
-    setModel(data!.model ?? "");
+    const nextProvider = data!.provider ?? "";
+    setProvider(nextProvider);
+    const presets = MODEL_PRESETS[nextProvider] ?? [];
+    const savedModel = data!.model ?? "";
+    if (savedModel && presets.includes(savedModel)) {
+      setModelChoice(savedModel);
+      setCustomModel("");
+    } else if (savedModel) {
+      setModelChoice(CUSTOM_MODEL_SENTINEL);
+      setCustomModel(savedModel);
+    } else {
+      setModelChoice("");
+      setCustomModel("");
+    }
     setBaseUrl(data!.baseUrl ?? "");
   }
 
+  const presets = MODEL_PRESETS[provider] ?? [];
+  const effectiveModel =
+    modelChoice === CUSTOM_MODEL_SENTINEL
+      ? customModel.trim()
+      : modelChoice.trim();
+
+  // Reset model dropdown when provider changes — the preset list is
+  // provider-specific. Don't wipe the custom model the user typed in
+  // case they wanted to keep using it (rare but cheap).
+  function handleProviderChange(next: string) {
+    setProvider(next);
+    setModelChoice("");
+  }
+
   const saveMutation = useMutation({
     mutationFn: async () => {
       const body: Record<string, unknown> = {
         provider: provider || null,
-        model: model || null,
+        model: effectiveModel || null,
         baseUrl: baseUrl || null,
       };
       if (anthropicKey.trim()) body.anthropicKey = anthropicKey.trim();
       if (localKey.trim()) body.localKey = localKey.trim();
+      if (openaiKey.trim()) body.openaiKey = openaiKey.trim();
       const res = await fetch("/api/user/ai-provider", {
         method: "PATCH",
         headers: { "Content-Type": "application/json" },
@@ -407,6 +474,7 @@ function UserAIProviderSubsection() {
       setSaveOk(true);
       setAnthropicKey("");
       setLocalKey("");
+      setOpenaiKey("");
       queryClient.invalidateQueries({ queryKey: ["user", "ai-provider"] });
       queryClient.invalidateQueries({ queryKey: ["insights"] });
     },
@@ -422,10 +490,11 @@ function UserAIProviderSubsection() {
     try {
       const overrideBody: Record<string, string> = {};
       if (provider) overrideBody.provider = provider;
-      if (model.trim()) overrideBody.model = model.trim();
+      if (effectiveModel) overrideBody.model = effectiveModel;
       if (baseUrl.trim()) overrideBody.baseUrl = baseUrl.trim();
       if (anthropicKey.trim()) overrideBody.anthropicKey = anthropicKey.trim();
       if (localKey.trim()) overrideBody.localKey = localKey.trim();
+      if (openaiKey.trim()) overrideBody.openaiKey = openaiKey.trim();
       const hasOverride = Object.keys(overrideBody).length > 0;
       const res = await fetch("/api/ai/test", {
         method: "POST",
@@ -460,7 +529,8 @@ function UserAIProviderSubsection() {
         <p className="text-sm font-medium">KI-Provider (persönlich)</p>
         <p className="text-muted-foreground text-xs">
           Eigener KI-Anbieter überschreibt die Admin-Einstellung. Leer lassen
-          für Standard.
+          für Standard. Für ChatGPT-Pro/Max-OAuth nutze den Verbinden-Button
+          oben.
         </p>
       </div>
 
@@ -470,34 +540,80 @@ function UserAIProviderSubsection() {
           <select
             id="ai-provider-select"
             value={provider}
-            onChange={(e) => setProvider(e.target.value)}
+            onChange={(e) => handleProviderChange(e.target.value)}
             className="bg-background border-input mt-1 h-9 w-full rounded-md border px-2 text-sm"
           >
             <option value="">— Standard (Admin/Codex) —</option>
-            <option value="OPENAI">OpenAI</option>
+            <option value="OPENAI">OpenAI (API-Key)</option>
             <option value="ANTHROPIC">Anthropic (Claude)</option>
             <option value="LOCAL">Lokal (OpenAI-kompatibel)</option>
-            <option value="CHATGPT_OAUTH">ChatGPT OAuth</option>
           </select>
         </div>
 
         <div>
-          <Label htmlFor="ai-model-input">Modell</Label>
-          <Input
-            id="ai-model-input"
-            value={model}
-            onChange={(e) => setModel(e.target.value)}
-            placeholder={
-              provider === "ANTHROPIC"
-                ? "claude-3-5-sonnet-latest"
-                : provider === "LOCAL"
-                  ? "llama3:8b"
-                  : "gpt-4o-mini"
-            }
-            className="mt-1"
-          />
+          <Label htmlFor="ai-model-select">Modell</Label>
+          <select
+            id="ai-model-select"
+            value={modelChoice}
+            onChange={(e) => setModelChoice(e.target.value)}
+            disabled={!provider}
+            className="bg-background border-input mt-1 h-9 w-full rounded-md border px-2 text-sm disabled:opacity-60"
+          >
+            <option value="">— Standard —</option>
+            {presets.map((m) => (
+              <option key={m} value={m}>
+                {m}
+              </option>
+            ))}
+            {provider && (
+              <option value={CUSTOM_MODEL_SENTINEL}>Eigenes…</option>
+            )}
+          </select>
         </div>
 
+        {modelChoice === CUSTOM_MODEL_SENTINEL && provider && (
+          <div className="sm:col-span-2">
+            <Label htmlFor="ai-model-custom">Eigener Modellname</Label>
+            <Input
+              id="ai-model-custom"
+              value={customModel}
+              onChange={(e) => setCustomModel(e.target.value)}
+              placeholder={
+                provider === "ANTHROPIC"
+                  ? "claude-3-5-sonnet-latest"
+                  : provider === "LOCAL"
+                    ? "llama3:8b"
+                    : "gpt-4o-mini"
+              }
+              className="mt-1"
+            />
+          </div>
+        )}
+
+        {provider === "OPENAI" && (
+          <div className="sm:col-span-2">
+            <Label htmlFor="ai-openai-key">
+              OpenAI API Key
+              {data?.hasOpenaiKey && (
+                <span className="text-muted-foreground ml-2 text-xs">
+                  (gespeichert {data.openaiKeyPreview})
+                </span>
+              )}
+            </Label>
+            <PasswordInput
+              id="ai-openai-key"
+              value={openaiKey}
+              onChange={(e) => setOpenaiKey(e.target.value)}
+              placeholder="sk-..."
+              className="mt-1"
+            />
+            <p className="text-muted-foreground mt-1 text-xs">
+              Eigener Key — keine Verbindung zu deinem ChatGPT-Abo. Für das
+              Abo nutze den Verbinden-Button oben.
+            </p>
+          </div>
+        )}
+
         {provider === "ANTHROPIC" && (
           <div className="sm:col-span-2">
             <Label htmlFor="ai-anthropic-key">

src/lib/ai/__tests__/codex-oauth.test.ts

@@ -1,5 +1,10 @@
-import { describe, it, expect } from "vitest";
-import { generatePKCE, generateState, buildAuthorizationUrl } from "../codex-oauth";
+import { afterEach, beforeEach, describe, it, expect } from "vitest";
+import {
+  generatePKCE,
+  generateState,
+  buildAuthorizationUrl,
+  CodexOAuthNotConfiguredError,
+} from "../codex-oauth";
 
 describe("codex-oauth", () => {
   describe("generatePKCE", () => {
@@ -29,6 +34,26 @@ describe("codex-oauth", () => {
   });
 
   describe("buildAuthorizationUrl", () => {
+    const ORIGINAL_CLIENT_ID = process.env.CODEX_OAUTH_CLIENT_ID;
+
+    beforeEach(() => {
+      // v1.4.3: the URL builder requires CODEX_OAUTH_CLIENT_ID. The
+      // v1.4.2 build silently dropped this so the resulting URL just
+      // hit chatgpt.com login with no OAuth grant flow at all — the
+      // "Connect with ChatGPT" button effectively did nothing in
+      // production. Setting an explicit value here keeps the test
+      // hermetic regardless of the runner env.
+      process.env.CODEX_OAUTH_CLIENT_ID = "test_client_id";
+    });
+
+    afterEach(() => {
+      if (ORIGINAL_CLIENT_ID === undefined) {
+        delete process.env.CODEX_OAUTH_CLIENT_ID;
+      } else {
+        process.env.CODEX_OAUTH_CLIENT_ID = ORIGINAL_CLIENT_ID;
+      }
+    });
+
     it("builds correct URL with all params", () => {
       const url = buildAuthorizationUrl({
         codeChallenge: "test-challenge",
@@ -40,10 +65,22 @@ describe("codex-oauth", () => {
       expect(parsed.origin).toBe("https://chatgpt.com");
       expect(parsed.pathname).toBe("/authorize");
       expect(parsed.searchParams.get("response_type")).toBe("code");
+      expect(parsed.searchParams.get("client_id")).toBe("test_client_id");
       expect(parsed.searchParams.get("code_challenge")).toBe("test-challenge");
       expect(parsed.searchParams.get("code_challenge_method")).toBe("S256");
       expect(parsed.searchParams.get("state")).toBe("test-state");
       expect(parsed.searchParams.get("redirect_uri")).toBe("https://example.com/callback");
     });
+
+    it("throws CodexOAuthNotConfiguredError when CODEX_OAUTH_CLIENT_ID is unset", () => {
+      delete process.env.CODEX_OAUTH_CLIENT_ID;
+      expect(() =>
+        buildAuthorizationUrl({
+          codeChallenge: "x",
+          state: "y",
+          redirectUri: "https://example.com/cb",
+        }),
+      ).toThrow(CodexOAuthNotConfiguredError);
+    });
   });
 });

src/lib/ai/codex-oauth.ts

@@ -15,6 +15,33 @@ export function generateState(): string {
   return base64url(randomBytes(32));
 }
 
+/**
+ * Throws when the operator has not configured `CODEX_OAUTH_CLIENT_ID` —
+ * the v1.4.2 build silently dropped the param and rendered a generic
+ * chatgpt.com login that never returned a code, so the "Connect with
+ * ChatGPT" button effectively did nothing. Failing here lets the route
+ * surface a 503 with an actionable message instead of redirecting to
+ * a dead-end page.
+ */
+export class CodexOAuthNotConfiguredError extends Error {
+  constructor() {
+    super(
+      "Codex OAuth is not configured on this instance — set CODEX_OAUTH_CLIENT_ID",
+    );
+    this.name = "CodexOAuthNotConfiguredError";
+  }
+}
+
+export function getCodexClientId(): string {
+  const id = process.env.CODEX_OAUTH_CLIENT_ID?.trim();
+  if (!id) throw new CodexOAuthNotConfiguredError();
+  return id;
+}
+
+export function isCodexOAuthConfigured(): boolean {
+  return Boolean(process.env.CODEX_OAUTH_CLIENT_ID?.trim());
+}
+
 export function buildAuthorizationUrl(params: {
   codeChallenge: string;
   state: string;
@@ -22,6 +49,7 @@ export function buildAuthorizationUrl(params: {
 }): string {
   const url = new URL("https://chatgpt.com/authorize");
   url.searchParams.set("response_type", "code");
+  url.searchParams.set("client_id", getCodexClientId());
   url.searchParams.set("code_challenge", params.codeChallenge);
   url.searchParams.set("code_challenge_method", "S256");
   url.searchParams.set("state", params.state);
@@ -46,6 +74,7 @@ export async function exchangeCodeForTokens(params: {
     headers: { "Content-Type": "application/json" },
     body: JSON.stringify({
       grant_type: "authorization_code",
+      client_id: getCodexClientId(),
       code: params.code,
       code_verifier: params.codeVerifier,
       redirect_uri: params.redirectUri,
@@ -65,6 +94,7 @@ export async function refreshAccessToken(refreshToken: string): Promise<TokenRes
     headers: { "Content-Type": "application/json" },
     body: JSON.stringify({
       grant_type: "refresh_token",
+      client_id: getCodexClientId(),
       refresh_token: refreshToken,
     }),
   });

src/lib/ai/provider.ts

@@ -32,11 +32,7 @@ type UserAIRow = {
   aiBaseUrl: string | null;
   aiAnthropicKeyEncrypted: string | null;
   aiLocalKeyEncrypted: string | null;
-  // legacy admin-key fallback (OpenAI uses adminAiKeyEncrypted via app_settings)
-  // We store user-level OpenAI key in aiAnthropicKeyEncrypted? No — for OPENAI
-  // selection at user-level we read app-settings admin key. The user override
-  // for OpenAI is intentionally minimal: provider+model+baseUrl. Personal keys
-  // are scoped to Anthropic/Local for now (matches the migration columns).
+  aiOpenaiKeyEncrypted: string | null;
 };
 
 /**
@@ -66,11 +62,19 @@ function buildUserProvider(row: UserAIRow): AIProvider | null {
         baseUrl: row.aiBaseUrl,
       });
     }
-    case "OPENAI":
-      // User selected OPENAI but personal keys live in admin app_settings;
-      // signal "use admin OpenAI" by returning null and letting caller fall
-      // through to resolveAdminProvider().
-      return null;
+    case "OPENAI": {
+      // v1.4.3: user-level OpenAI key gets first crack — only fall back
+      // to the admin key if the user hasn't supplied their own. The
+      // model-default mirrors the admin path for consistency so a saved
+      // user "OPENAI" without an explicit model still produces an
+      // OpenAIClient with `gpt-4o-mini`.
+      if (!row.aiOpenaiKeyEncrypted) return null;
+      return new OpenAIClient({
+        apiKey: decrypt(row.aiOpenaiKeyEncrypted),
+        model: row.aiModel ?? "gpt-4o-mini",
+        baseUrl: row.aiBaseUrl ?? "https://api.openai.com/v1",
+      });
+    }
     case "CHATGPT_OAUTH":
       // Caller handles Codex OAuth via the dedicated branch; signal here.
       return null;
@@ -209,6 +213,7 @@ export async function resolveProvider(userId: string): Promise<AIProvider> {
       aiBaseUrl: true,
       aiAnthropicKeyEncrypted: true,
       aiLocalKeyEncrypted: true,
+      aiOpenaiKeyEncrypted: true,
     },
   });
 
@@ -241,6 +246,7 @@ export type AITestOverride = {
   baseUrl?: string | null;
   anthropicKey?: string | null;
   localKey?: string | null;
+  openaiKey?: string | null;
 };
 
 export class AITestConfigError extends Error {
@@ -270,6 +276,7 @@ export async function resolveProviderForTest(
       aiBaseUrl: true,
       aiAnthropicKeyEncrypted: true,
       aiLocalKeyEncrypted: true,
+      aiOpenaiKeyEncrypted: true,
     },
   });
 
@@ -333,11 +340,27 @@ export async function resolveProviderForTest(
       throw new AITestConfigError(422, "ChatGPT OAuth is not connected");
     }
     case "OPENAI": {
+      // Test path mirrors the persistent resolution: user key first,
+      // admin fallback if absent. We accept an `openaiKey` override
+      // from the test endpoint so a user can verify a not-yet-saved
+      // key dropdown change without persisting anything.
+      const userKey =
+        override.openaiKey?.trim() ||
+        (stored?.aiOpenaiKeyEncrypted
+          ? decrypt(stored.aiOpenaiKeyEncrypted)
+          : "");
+      if (userKey) {
+        return new OpenAIClient({
+          apiKey: userKey,
+          model: model || "gpt-4o-mini",
+          baseUrl: baseUrl || "https://api.openai.com/v1",
+        });
+      }
       const admin = await resolveAdminProvider();
       if (admin.type === "none") {
         throw new AITestConfigError(
           422,
-          "Admin OpenAI key is not configured for this instance",
+          "OpenAI key not configured (neither user nor admin)",
         );
       }
       return admin;