fix(quizzes): add configurable timeout to AI service fetch

src/config/index.ts

@@ -39,6 +39,7 @@
 
   // AI service (chainlearn-ai) used for quiz generation
   AI_SERVICE_URL: z.string().url().default("http://localhost:8000"),
+  AI_TIMEOUT_MS: z.coerce.number().default(30_000),
 });
 
 export type Env = z.infer<typeof envSchema>;
@@ -88,6 +89,6 @@
 // Lazy config — loadConfig() only runs on first property access, not at import time
 export const config: Env = new Proxy({} as Env, {
   get(_, prop) {
     return (ensureConfig() as any)[prop];
   },
 });

src/modules/quizzes/ai-client.ts

@@ -25,26 +25,40 @@ export interface GenerateQuizFromAIParams {
 export async function generateQuizFromAI(
   params: GenerateQuizFromAIParams
 ): Promise<AiQuizQuestion[]> {
-  const response = await fetch(`${config.AI_SERVICE_URL}/generate-quiz`, {
-    method: "POST",
-    headers: { "Content-Type": "application/json" },
-    body: JSON.stringify({
-      user_id: params.userId,
-      course_id: params.courseId,
-      module_id: params.moduleId,
-      difficulty: params.difficulty,
-      num_questions: params.numQuestions,
-    }),
-  });
-
-  if (!response.ok) {
-    logger.error(
-      { status: response.status },
-      "AI service quiz generation failed"
-    );
-    throw new Error(`AI service returned ${response.status}`);
-  }
+  const controller = new AbortController();
+  const timeout = setTimeout(() => controller.abort(), config.AI_TIMEOUT_MS);
+
+  try {
+    const response = await fetch(`${config.AI_SERVICE_URL}/generate-quiz`, {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify({
+        user_id: params.userId,
+        course_id: params.courseId,
+        module_id: params.moduleId,
+        difficulty: params.difficulty,
+        num_questions: params.numQuestions,
+      }),
+      signal: controller.signal,
+    });
 
-  const data = (await response.json()) as AiQuizResponse;
-  return data.questions;
+    if (!response.ok) {
+      logger.error(
+        { status: response.status },
+        "AI service quiz generation failed"
+      );
+      throw new Error(`AI service returned ${response.status}`);
+    }
+
+    const data = (await response.json()) as AiQuizResponse;
+    return data.questions;
+  } catch (err) {
+    if (err instanceof Error && err.name === "AbortError") {
+      logger.error({ timeout: config.AI_TIMEOUT_MS }, "AI service request timed out");
+      throw new Error(`AI service request timed out after ${config.AI_TIMEOUT_MS}ms`);
+    }
+    throw err;
+  } finally {
+    clearTimeout(timeout);
+  }
 }