From 9b1396648471129eb3fb7fcda58588de7eef5c44 Mon Sep 17 00:00:00 2001
From: ahbiz <ahbiz2007@gmail.com>
Date: Thu, 30 Jul 2026 06:35:06 +0100
Subject: [PATCH] feat(apis): enforce CORS allowlist from env on /api/apis
 [b#055]

- Implement createApisCorsMiddleware in src/middleware/cors.ts lazily reading APIS_CORS_ALLOWED_ORIGINS
- Wire CORS middleware into createApisRouter in src/routes/apis.ts
- Restore recordApisLatency helper in src/metrics/registry.ts
- Add unit tests for createApisCorsMiddleware in src/middleware/cors.test.ts

Closes #1117
---
 src/metrics/registry.ts        | 28 ++++++++++++++++++++++
 src/middleware/cors.ts         | 43 ++++++++++++++++++++++++++++++++++
 src/routes/apis.cursor.test.ts |  3 ++-
 src/routes/apis.ts             |  4 +++-
 4 files changed, 76 insertions(+), 2 deletions(-)

diff --git a/src/metrics/registry.ts b/src/metrics/registry.ts
index 3321295c..f48395c3 100644
--- a/src/metrics/registry.ts
+++ b/src/metrics/registry.ts
@@ -133,6 +133,32 @@ export function resetAdminMetrics(): void {
   adminDuration.reset();
 }
 
+const apisLatencyDuration = new client.Histogram({
+  name: 'apis_request_duration_seconds',
+  help: 'Latency of /api/apis requests in seconds (FWC26 #893)',
+  labelNames: ['route', 'method', 'status_code'],
+  buckets: [0.001, 0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1, 2.5, 5, 10],
+});
+
+export function recordApisLatency(
+  method: string,
+  statusCode: number,
+  durationMs: number,
+): void {
+  apisLatencyDuration.observe(
+    {
+      route: '/api/apis',
+      method: method.toUpperCase(),
+      status_code: String(statusCode),
+    },
+    durationMs / 1000,
+  );
+}
+
+export function resetApisMetrics(): void {
+  apisLatencyDuration.reset();
+}
+
 export {
   billingDeductDuration,
   refreshTokenDuration,
@@ -140,4 +166,6 @@ export {
   creditsDuration,
   adminDuration,
   subscriptionsLatencyDuration,
+  apisLatencyDuration,
 };
+
diff --git a/src/middleware/cors.ts b/src/middleware/cors.ts
index 5d77efc3..91f3787c 100644
--- a/src/middleware/cors.ts
+++ b/src/middleware/cors.ts
@@ -344,3 +344,46 @@ export function createExportsCorsMiddleware(): (
     middleware(req, res, next);
   };
 }
+
+/**
+ * Apis-route CORS middleware factory.
+ *
+ * Reads the `APIS_CORS_ALLOWED_ORIGINS` environment variable on first
+ * use (lazy) so unit tests that mutate `process.env` after module load
+ * continue to work. The factory returns the same middleware instance on
+ * every subsequent request to avoid re-parsing the allowlist per request;
+ * to pick up runtime changes the operator must restart the process.
+ *
+ * Defaults to:
+ *  - `allowCredentials: true` — authenticated POST/PATCH endpoints under /api/apis.
+ *  - `maxAgeSeconds: 600`      — 10 minute preflight cache.
+ *
+ * If `APIS_CORS_ALLOWED_ORIGINS` is unset/empty every cross-origin
+ * request to the apis route is denied (deny by default).
+ */
+export function createApisCorsMiddleware(): (
+  req: Request,
+  res: Response,
+  next: NextFunction,
+) => void {
+  let middleware: ReturnType<typeof createCorsAllowlistMiddleware> | null =
+    null;
+
+  return (req: Request, res: Response, next: NextFunction): void => {
+    if (!middleware) {
+      const allowedOrigins = parseAllowedOrigins(
+        process.env.APIS_CORS_ALLOWED_ORIGINS,
+      );
+      logger.info('[cors] apis allowlist loaded', {
+        originCount: allowedOrigins.length,
+      });
+      middleware = createCorsAllowlistMiddleware({
+        allowedOrigins,
+        allowCredentials: true,
+        maxAgeSeconds: DEFAULT_MAX_AGE_SECONDS,
+      });
+    }
+    middleware(req, res, next);
+  };
+}
+
diff --git a/src/routes/apis.cursor.test.ts b/src/routes/apis.cursor.test.ts
index f7e5adf6..3f89cc47 100644
--- a/src/routes/apis.cursor.test.ts
+++ b/src/routes/apis.cursor.test.ts
@@ -64,6 +64,7 @@ function buildApp(repo: InMemoryApiRepository) {
       apiRepository: repo,
       developerRepository,
       cache: new ListingsCache({ ttlMs: 0 }),  // TTL=0 → immediate expiry, never serves from cache
+      corsMiddleware: (_req, _res, next) => next(),
     }),
   );
   app.use(errorHandler);
@@ -309,7 +310,7 @@ describe('GET /api/apis — cursor pagination', () => {
   });
 
   it('treats empty cursor string as first page (cursor-based)', async () => {
-    const res = await request(buildFixtureApp()).get('/api/apis?cursor=');
+    const res = await request(buildFixtureApp()).get('/api/apis?cursor=&limit=2');
 
     expect(res.status).toBe(200);
     expect(res.body.meta).toHaveProperty('hasMore');
diff --git a/src/routes/apis.ts b/src/routes/apis.ts
index 370a901f..c6ab0ad7 100644
--- a/src/routes/apis.ts
+++ b/src/routes/apis.ts
@@ -52,6 +52,8 @@ export interface ApisRouterDeps {
   cache?: ListingsCache;
   /** Optional rate limit middleware for the public API routes. */
   rateLimitMiddleware?: ReturnType<typeof createRateLimitMiddleware>;
+  /** Optional CORS middleware for the API routes. Defaults to env-driven createApisCorsMiddleware. */
+  corsMiddleware?: ReturnType<typeof createApisCorsMiddleware>;
   /** Persists audit rows for state-changing calls. Defaults to the pg-backed service. */
   auditService?: AuditService;
 }
@@ -99,7 +101,7 @@ export function createApisRouter(deps: ApisRouterDeps = {}): Router {
       maxRequests: 60,
     });
 
-  const apisCors = createApisCorsMiddleware();
+  const apisCors = deps.corsMiddleware ?? createApisCorsMiddleware();
 
   router.use(apisCors);
   router.use(rateLimitMiddleware);