fix(images): normalize image endpoint error format (#9981)

changelog.d/fixes/9981-image-error-normalization.md

@@ -0,0 +1 @@
+- fix(images): normalize terminal upstream errors via OpenAI-standard type/code (#9981)

src/app/api/v1/images/generations/route.ts

@@ -308,10 +308,11 @@ async function postHandler(request, context) {
   }
 
   const errorPayload = toJsonErrorPayload((result as any).error, "Image generation provider error");
-  return new Response(JSON.stringify(errorPayload), {
-    status: (result as any).status,
-    headers: { "Content-Type": "application/json" },
-  });
+  const message =
+    typeof errorPayload?.error?.message === "string"
+      ? errorPayload.error.message
+      : "Image generation provider error";
+  return errorResponse((result as any).status, message);
 }
 
 export const POST = withInjectionGuard(postHandler);

src/app/api/v1/providers/[provider]/images/generations/route.ts

@@ -119,8 +119,9 @@ export async function POST(request, { params }) {
   }
 
   const errorPayload = toJsonErrorPayload((result as any).error, "Image generation provider error");
-  return new Response(JSON.stringify(errorPayload), {
-    status: (result as any).status,
-    headers: { "Content-Type": "application/json" },
-  });
+  const message =
+    typeof errorPayload?.error?.message === "string"
+      ? errorPayload.error.message
+      : "Image generation provider error";
+  return errorResponse((result as any).status, message);
 }

tests/unit/image-generation-route.test.ts

@@ -701,6 +701,67 @@ test("provider-scoped image generation POST uses the shared 401 account fallback
   ]);
 });
 
+test("v1 image generation POST normalizes a terminal upstream 401 to the OpenAI-standard error shape", async () => {
+  await seedConnection("openai", { apiKey: "single-expired-image-key" });
+
+  globalThis.fetch = async (url, options: RequestInit = {}) => {
+    assert.equal(String(url), "https://api.openai.com/v1/images/generations");
+    const authorization = new Headers(options.headers).get("authorization") ?? "";
+    assert.equal(authorization, "Bearer single-expired-image-key");
+    return new Response(JSON.stringify({ error: { message: "expired access token" } }), {
+      status: 401,
+      headers: { "content-type": "application/json" },
+    });
+  };
+
+  const response = await imageRoute.POST(
+    new Request("http://localhost/api/v1/images/generations", {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify({ model: "openai/gpt-image-2", prompt: "normalize terminal 401" }),
+    })
+  );
+  const body = (await response.json()) as ErrorResponseBody;
+
+  assert.equal(response.status, 401);
+  assert.deepEqual(body.error, {
+    message: "expired access token",
+    type: "authentication_error",
+    code: "invalid_api_key",
+  });
+});
+
+test("provider-scoped image generation POST normalizes a terminal upstream 401 to the OpenAI-standard error shape", async () => {
+  await seedConnection("openai", { apiKey: "provider-single-expired-key" });
+
+  globalThis.fetch = async (url, options: RequestInit = {}) => {
+    assert.equal(String(url), "https://api.openai.com/v1/images/generations");
+    const authorization = new Headers(options.headers).get("authorization") ?? "";
+    assert.equal(authorization, "Bearer provider-single-expired-key");
+    return new Response(JSON.stringify({ error: { message: "expired provider token" } }), {
+      status: 401,
+      headers: { "content-type": "application/json" },
+    });
+  };
+
+  const response = await providerImageRoute.POST(
+    new Request("http://localhost/api/v1/providers/openai/images/generations", {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify({ model: "gpt-image-2", prompt: "normalize provider terminal 401" }),
+    }),
+    { params: Promise.resolve({ provider: "openai" }) }
+  );
+  const body = (await response.json()) as ErrorResponseBody;
+
+  assert.equal(response.status, 401);
+  assert.deepEqual(body.error, {
+    message: "expired provider token",
+    type: "authentication_error",
+    code: "invalid_api_key",
+  });
+});
+
 test("v1 image generation POST refreshes an expired Antigravity token before dispatch", async () => {
   await seedConnection("antigravity", {
     authType: "oauth",