diff --git a/.gitignore b/.gitignore
index d8421de..893cde7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,3 +5,4 @@ dist/
 !.env.example
 *.log
 .DS_Store
+.idea/
diff --git a/package.json b/package.json
index a3698f3..86c686a 100644
--- a/package.json
+++ b/package.json
@@ -7,7 +7,7 @@
   "scripts": {
     "dev": "tsx watch src/index.ts",
     "build": "tsc",
-    "start": "node dist/index.js",
+    "start": "node --env-file=.env dist/index.js",
     "test": "vitest run",
     "typecheck": "tsc --noEmit"
   },
diff --git a/src/index.ts b/src/index.ts
index ca6093f..938aa64 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,6 +1,26 @@
+import { readFileSync } from "node:fs";
+import { fileURLToPath } from "node:url";
+import { dirname, resolve } from "node:path";
 import Fastify from "fastify";
 import { aiRoutes } from "./routes/ai.js";
 
+// ===== 加载 .env（零依赖，兼容 dev/start 两种启动方式）=====
+const __dirname = dirname(fileURLToPath(import.meta.url));
+const envPath = resolve(__dirname, "..", ".env");
+try {
+  for (const line of readFileSync(envPath, "utf-8").split(/\r?\n/)) {
+    const trimmed = line.trim();
+    if (!trimmed || trimmed.startsWith("#")) continue;
+    const eq = trimmed.indexOf("=");
+    if (eq === -1) continue;
+    const k = trimmed.slice(0, eq).trim();
+    const v = trimmed.slice(eq + 1).trim();
+    if (k && !(k in process.env)) process.env[k] = v;
+  }
+} catch {
+  // .env not found, use system environment
+}
+
 const app = Fastify({
   logger: {
     level: "info",