diff --git a/frontend/server.ts b/frontend/server.ts
index 65e20c0..7dc0ee7 100644
--- a/frontend/server.ts
+++ b/frontend/server.ts
@@ -9,10 +9,12 @@ import { HttpAgent, Middleware, EventType } from "@ag-ui/client";
 import { Observable } from "rxjs";
 import { Hono } from "hono";
 
-const AGENT_URL =
-  process.env.AGENT_URL ?? "http://backend:8000/api/v1/agent/agui";
 const BACKEND_URL =
   process.env.BACKEND_URL ?? "http://localhost:8001";
+// Prod sets AGENT_URL explicitly (compose network); the default derives from
+// BACKEND_URL so local dev reaches the docker backend published on :8001.
+const AGENT_URL =
+  process.env.AGENT_URL ?? `${BACKEND_URL}/api/v1/agent/agui`;
 
 const isProd = process.env.NODE_ENV === "production";
 const PORT = parseInt(process.env.PORT ?? (isProd ? "3000" : "3001"));