From f3f66ee9248e832cc9e76fa12e70113731ca33f5 Mon Sep 17 00:00:00 2001
From: Henry Li <henry1943@163.com>
Date: Mon, 19 Jan 2026 11:23:40 +0800
Subject: [PATCH] feat: add NEXT_PUBLIC_BACKEND_BASE_URL

---
 frontend/.env.example                |  3 +++
 frontend/src/core/api/api-client.ts  | 10 +++-------
 frontend/src/core/artifacts/utils.ts |  3 ++-
 frontend/src/core/config/index.ts    |  5 +++++
 frontend/src/env.js                  |  8 ++++++--
 5 files changed, 19 insertions(+), 10 deletions(-)
 create mode 100644 frontend/src/core/config/index.ts

diff --git a/frontend/.env.example b/frontend/.env.example
index 3f5fac5..f1d671f 100644
--- a/frontend/.env.example
+++ b/frontend/.env.example
@@ -9,6 +9,9 @@
 # When adding additional environment variables, the schema in "/src/env.js"
 # should be updated accordingly.
 
+# The base URL of DeerFlow's backend service
+NEXT_PUBLIC_BACKEND_BASE_URL="http://localhost:8000"
+
 # Better Auth
 ## Better Auth - Google OAuth
 BETTER_AUTH_GOOGLE_CLIENT_ID=""
diff --git a/frontend/src/core/api/api-client.ts b/frontend/src/core/api/api-client.ts
index e8197a9..0672d10 100644
--- a/frontend/src/core/api/api-client.ts
+++ b/frontend/src/core/api/api-client.ts
@@ -2,16 +2,12 @@
 
 import { Client as LangGraphClient } from "@langchain/langgraph-sdk/client";
 
+import { getBackendBaseURL } from "../config";
+
 let _singleton: LangGraphClient | null = null;
 export function getAPIClient(): LangGraphClient {
-  let url: URL | null = null;
-  if (typeof window === "undefined") {
-    url = new URL("/api/langgraph", "http://localhost:3000");
-  } else {
-    url = new URL("/api/langgraph", window.location.origin);
-  }
   _singleton ??= new LangGraphClient({
-    apiUrl: "http://localhost:2024",
+    apiUrl: getBackendBaseURL(),
   });
   return _singleton;
 }
diff --git a/frontend/src/core/artifacts/utils.ts b/frontend/src/core/artifacts/utils.ts
index 8f1eccd..5dc03e3 100644
--- a/frontend/src/core/artifacts/utils.ts
+++ b/frontend/src/core/artifacts/utils.ts
@@ -1,3 +1,4 @@
+import { getBackendBaseURL } from "../config";
 import type { AgentThread } from "../threads";
 
 export function urlOfArtifact({
@@ -9,7 +10,7 @@ export function urlOfArtifact({
   threadId: string;
   download?: boolean;
 }) {
-  return `http://localhost:8000/api/threads/${threadId}/artifacts${filepath}${download ? "?download=true" : ""}`;
+  return `${getBackendBaseURL()}/api/threads/${threadId}/artifacts${filepath}${download ? "?download=true" : ""}`;
 }
 
 export function extractArtifactsFromThread(thread: AgentThread) {
diff --git a/frontend/src/core/config/index.ts b/frontend/src/core/config/index.ts
new file mode 100644
index 0000000..a9cfba0
--- /dev/null
+++ b/frontend/src/core/config/index.ts
@@ -0,0 +1,5 @@
+import { env } from "@/env";
+
+export function getBackendBaseURL() {
+  return env.NEXT_PUBLIC_BACKEND_BASE_URL ?? "http://localhost:8000";
+}
diff --git a/frontend/src/env.js b/frontend/src/env.js
index 52a4bbe..ebff7e1 100644
--- a/frontend/src/env.js
+++ b/frontend/src/env.js
@@ -24,7 +24,10 @@ export const env = createEnv({
    * `NEXT_PUBLIC_`.
    */
   client: {
-    // NEXT_PUBLIC_CLIENTVAR: z.string(),
+    NEXT_PUBLIC_BACKEND_BASE_URL: z
+      .string()
+      .optional()
+      .default("http://localhost:8000/api"),
   },
 
   /**
@@ -37,7 +40,8 @@ export const env = createEnv({
     BETTER_AUTH_GITHUB_CLIENT_SECRET:
       process.env.BETTER_AUTH_GITHUB_CLIENT_SECRET,
     NODE_ENV: process.env.NODE_ENV,
-    // NEXT_PUBLIC_CLIENTVAR: process.env.NEXT_PUBLIC_CLIENTVAR,
+
+    NEXT_PUBLIC_BACKEND_BASE_URL: process.env.NEXT_PUBLIC_BACKEND_BASE_URL,
   },
   /**
    * Run `build` or `dev` with `SKIP_ENV_VALIDATION` to skip env validation. This is especially