diff --git a/apps/web/vite.config.ts b/apps/web/vite.config.ts
index ace127e..1d8ae59 100644
--- a/apps/web/vite.config.ts
+++ b/apps/web/vite.config.ts
@@ -1,20 +1,28 @@
-import { fileURLToPath, URL } from 'node:url'
+import { fileURLToPath, URL } from "node:url";
 
-import { defineConfig } from 'vite'
-import vue from '@vitejs/plugin-vue'
-import vueJsx from '@vitejs/plugin-vue-jsx'
-import vueDevTools from 'vite-plugin-vue-devtools'
+import { defineConfig } from "vite";
+import vue from "@vitejs/plugin-vue";
+import vueJsx from "@vitejs/plugin-vue-jsx";
+import vueDevTools from "vite-plugin-vue-devtools";
+
+/** 后端母体端口（与根 .env 的 PORT / AGENTS 约定一致） */
+const API_TARGET = process.env.VITE_API_PROXY_TARGET ?? "http://127.0.0.1:18456";
 
 // https://vite.dev/config/
 export default defineConfig({
-  plugins: [
-    vue(),
-    vueJsx(),
-    vueDevTools(),
-  ],
+  plugins: [vue(), vueJsx(), vueDevTools()],
   resolve: {
     alias: {
-      '@': fileURLToPath(new URL('./src', import.meta.url)),
+      "@": fileURLToPath(new URL("./src", import.meta.url)),
     },
   },
-})
+  server: {
+    proxy: {
+      // 契约：/api/* 专属接口；SPA 路由不进 /api（公共约定 §2）
+      "/api": {
+        target: API_TARGET,
+        changeOrigin: true,
+      },
+    },
+  },
+});