1 files changed, 48 insertions, 0 deletions
diff --git a/packages/trpc/lib/rateLimit.ts b/packages/trpc/lib/rateLimit.ts
new file mode 100644
index 00000000..bf8a8e8b
--- /dev/null
+++ b/packages/trpc/lib/rateLimit.ts
@@ -0,0 +1,48 @@
+import { TRPCError } from "@trpc/server";
+
+import type { RateLimitConfig } from "@karakeep/shared/ratelimiting";
+import serverConfig from "@karakeep/shared/config";
+import { getRateLimitClient } from "@karakeep/shared/ratelimiting";
+
+/**
+ * Create a tRPC middleware for rate limiting
+ * @param config Rate limit configuration
+ * @returns tRPC middleware function
+ */
+export function createRateLimitMiddleware<T>(config: RateLimitConfig) {
+  return async function rateLimitMiddleware(opts: {
+    path: string;
+    ctx: { req: { ip: string | null } };
+    next: () => Promise<T>;
+  }) {
+    if (!serverConfig.rateLimiting.enabled) {
+      return opts.next();
+    }
+
+    const ip = opts.ctx.req.ip;
+
+    if (!ip) {
+      return opts.next();
+    }
+
+    const client = await getRateLimitClient();
+
+    if (!client) {
+      // If no rate limit client is registered, allow the request
+      return opts.next();
+    }
+
+    // Build the rate limiting key from IP and path
+    const key = `${ip}:${opts.path}`;
+    const result = client.checkRateLimit(config, key);
+
+    if (!result.allowed) {
+      throw new TRPCError({
+        code: "TOO_MANY_REQUESTS",
+        message: `Rate limit exceeded. Try again in ${result.resetInSeconds} seconds.`,
+      });
+    }
+
+    return opts.next();
+  };
+}