fix(frontend): route agent checks to gateway (#1572)

* fix(frontend): route agent checks to gateway

* fix(frontend): proxy langgraph requests locally

* fix(frontend): keep zh-CN text readable

* fix(frontend): add exact local api rewrites

* fix(frontend): support docker-safe internal rewrites

* Update frontend/src/core/agents/api.ts

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Willem Jiang <willem.jiang@gmail.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

frontend/next.config.js

@@ -4,9 +4,51 @@
  */
 import "./src/env.js";
 
+function getInternalServiceURL(envKey, fallbackURL) {
+  const configured = process.env[envKey]?.trim();
+  return configured && configured.length > 0
+    ? configured.replace(/\/+$/, "")
+    : fallbackURL;
+}
+
 /** @type {import("next").NextConfig} */
 const config = {
   devIndicators: false,
+  async rewrites() {
+    const rewrites = [];
+    const langgraphURL = getInternalServiceURL(
+      "DEER_FLOW_INTERNAL_LANGGRAPH_BASE_URL",
+      "http://127.0.0.1:2024",
+    );
+    const gatewayURL = getInternalServiceURL(
+      "DEER_FLOW_INTERNAL_GATEWAY_BASE_URL",
+      "http://127.0.0.1:8001",
+    );
+
+    if (!process.env.NEXT_PUBLIC_LANGGRAPH_BASE_URL) {
+      rewrites.push({
+        source: "/api/langgraph",
+        destination: langgraphURL,
+      });
+      rewrites.push({
+        source: "/api/langgraph/:path*",
+        destination: `${langgraphURL}/:path*`,
+      });
+    }
+
+    if (!process.env.NEXT_PUBLIC_BACKEND_BASE_URL) {
+      rewrites.push({
+        source: "/api/agents",
+        destination: `${gatewayURL}/api/agents`,
+      });
+      rewrites.push({
+        source: "/api/agents/:path*",
+        destination: `${gatewayURL}/api/agents/:path*`,
+      });
+    }
+
+    return rewrites;
+  },
 };
 
 export default config;