diff --git a/.gitignore b/.gitignore
index f03eaec..fb41c10 100644
--- a/.gitignore
+++ b/.gitignore
@@ -15,3 +15,6 @@ node_modules
 
 #!.yarn/cache
 .pnp.*
+
+.env
+.env.*
diff --git a/package.json b/package.json
index d7b04d5..2371128 100644
--- a/package.json
+++ b/package.json
@@ -3,19 +3,21 @@
   "packageManager": "yarn@4.18.0",
   "type": "module",
   "scripts": {
-     "dev": "tsx --watch ./src/index.ts",
-  "start": "node ./dist/index.js",
-  "build": "tsc",
-  "clean": "rm -rf dist",
-  "compile": "yarn clean && yarn build",
-  "script": "tsx"
+    "dev": "tsx --watch ./src/index.ts",
+    "start": "node ./dist/index.js",
+    "build": "tsc",
+    "clean": "rm -rf dist",
+    "compile": "yarn clean && yarn build",
+    "script": "tsx"
   },
   "dependencies": {
     "@jig-software/trest": "2.0.0-beta",
     "@koa/cors": "^5.0.0",
     "@koa/router": "^15.7.0",
+    "dotenv": "^17.4.2",
     "koa": "^3.2.1",
-    "koa-bodyparser": "^4.4.1"
+    "koa-bodyparser": "^4.4.1",
+    "path": "^0.12.7"
   },
   "devDependencies": {
     "@types/koa": "^3.0.3",
diff --git a/src/configs/index.ts b/src/configs/index.ts
new file mode 100644
index 0000000..252cdf9
--- /dev/null
+++ b/src/configs/index.ts
@@ -0,0 +1,13 @@
+import dotenv from 'dotenv';
+import path from 'path';
+
+// 💡 1. 讓 dotenv 去讀取根目錄的 .env 檔案並注入到 process.env
+dotenv.config(); 
+
+// 💡 2. 集中導出一個帶有型別的物件
+export const config = {
+  port: parseInt(process.env.PORT || '3000', 10),
+  //dbUrl: process.env.DB_URL || 'mongodb://localhost:27017/default',
+  //jwtSecret: process.env.JWT_SECRET || 'fallback_secret',
+  //isConfigured: !!process.env.DB_URL
+};
diff --git a/src/controllers/userController.ts b/src/controllers/userController.ts
new file mode 100644
index 0000000..9126a6c
--- /dev/null
+++ b/src/controllers/userController.ts
@@ -0,0 +1,31 @@
+import type { Context } from "koa";
+
+// Simulated database array
+const users = [
+  { id: 1, name: 'Alice' },
+  { id: 2, name: 'Bob' }
+];
+
+export async function getAllUsers(ctx:Context) {
+  ctx.body = { success: true, data: users };
+}
+
+export async function createUser(ctx: Context) {
+  const body = ctx.request.body;
+
+  if (
+    typeof body !== "object" ||
+    body === null ||
+    !("name" in body) ||
+    typeof body.name !== "string" ||
+    body.name.trim() === ""
+  ) {
+    ctx.throw(400, 'Name field is required');
+  }
+
+  const newUser = { id: users.length + 1, name: body.name };
+  users.push(newUser);
+
+  ctx.status = 201;
+  ctx.body = { success: true, data: newUser };
+}
diff --git a/src/index.ts b/src/index.ts
index a1f33ed..97f41e9 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,19 +1,24 @@
 import Koa from 'koa';
 import cors from '@koa/cors';
 import bodyParser from 'koa-bodyparser';
-//import { errorHandler } from './middleware/error';
-//import userRouter from './routes/userRoutes';
+import { errorHandler } from './middleware/error.js';
+import userRouter from './routes/userRoutes.js';
+
+import { config } from './configs/index.js';
 
 const app = new Koa();
-const PORT = 3000;
+const PORT = config.port || 3000;
 
-//app.use(errorHandler);
-app.use(cors());
-app.use(bodyParser());
+// --- Middlewares Stack (Order Matters!) ---
 
-//app.use(userRouter.routes());
-//app.use(userRouter.allowedMethods());
+app.use(errorHandler);                      // 1. Error interceptor (Outer Onion layer)
+app.use(cors());                            // 2. Enable Cross-Origin requests
+app.use(bodyParser());                      // 3. Parse JSON incoming bodies
+
+// --- Routes Registration ---
+app.use(userRouter.routes());
+app.use(userRouter.allowedMethods());       // Handles automatic 405 Method Not Allowed responses
 
 app.listen(PORT, () => {
-  console.log(`🚀 TypeScript Koa server running at http://localhost:${PORT}`);
+  console.log(`🚀 Koa server running smoothly at http://localhost:${PORT}`);
 });
diff --git a/src/routes/userRoutes.ts b/src/routes/userRoutes.ts
new file mode 100644
index 0000000..5839f10
--- /dev/null
+++ b/src/routes/userRoutes.ts
@@ -0,0 +1,9 @@
+import Router from '@koa/router';
+import { getAllUsers, createUser } from '../controllers/userController.js';
+
+const router = new Router({ prefix: '/api/users' });
+
+router.get('/', getAllUsers);
+router.post('/', createUser);
+
+export default router;
diff --git a/yarn.lock b/yarn.lock
index d7a61fd..db5eeea 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -645,6 +645,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"dotenv@npm:^17.4.2":
+  version: 17.4.2
+  resolution: "dotenv@npm:17.4.2"
+  checksum: 10c0/164f8e77a646c8446867d5b588d26ea6005c8ea7c5eb41cf926f6113d23f2191355f6e0cfd95ea9bab98394a5b0a3f1e51a8399711b666fe55cc7b0bd745f942
+  languageName: node
+  linkType: hard
+
 "dunder-proto@npm:^1.0.1":
   version: 1.0.1
   resolution: "dunder-proto@npm:1.0.1"
@@ -1000,6 +1007,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"inherits@npm:2.0.3":
+  version: 2.0.3
+  resolution: "inherits@npm:2.0.3"
+  checksum: 10c0/6e56402373149ea076a434072671f9982f5fad030c7662be0332122fe6c0fa490acb3cc1010d90b6eff8d640b1167d77674add52dfd1bb85d545cf29e80e73e7
+  languageName: node
+  linkType: hard
+
 "inherits@npm:2.0.4, inherits@npm:~2.0.4":
   version: 2.0.4
   resolution: "inherits@npm:2.0.4"
@@ -1286,6 +1300,16 @@ __metadata:
   languageName: node
   linkType: hard
 
+"path@npm:^0.12.7":
+  version: 0.12.7
+  resolution: "path@npm:0.12.7"
+  dependencies:
+    process: "npm:^0.11.1"
+    util: "npm:^0.10.3"
+  checksum: 10c0/f795ce5438a988a590c7b6dfd450ec9baa1c391a8be4c2dea48baa6e0f5b199e56cd83b8c9ebf3991b81bea58236d2c32bdafe2c17a2e70c3a2e4c69891ade59
+  languageName: node
+  linkType: hard
+
 "picomatch@npm:^2.0.4, picomatch@npm:^2.2.1":
   version: 2.3.2
   resolution: "picomatch@npm:2.3.2"
@@ -1307,6 +1331,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"process@npm:^0.11.1":
+  version: 0.11.10
+  resolution: "process@npm:0.11.10"
+  checksum: 10c0/40c3ce4b7e6d4b8c3355479df77aeed46f81b279818ccdc500124e6a5ab882c0cc81ff7ea16384873a95a74c4570b01b120f287abbdd4c877931460eca6084b3
+  languageName: node
+  linkType: hard
+
 "pstree.remy@npm:^1.1.8":
   version: 1.1.8
   resolution: "pstree.remy@npm:1.1.8"
@@ -1450,9 +1481,11 @@ __metadata:
     "@types/koa-bodyparser": "npm:^4"
     "@types/koa__cors": "npm:^5"
     "@types/node": "npm:^26.4.1"
+    dotenv: "npm:^17.4.2"
     koa: "npm:^3.2.1"
     koa-bodyparser: "npm:^4.4.1"
     nodemon: "npm:^3.1.14"
+    path: "npm:^0.12.7"
     tsx: "npm:^4.23.13"
     typescript: "npm:^5.9.3"
   languageName: unknown
@@ -1606,6 +1639,15 @@ __metadata:
   languageName: node
   linkType: hard
 
+"util@npm:^0.10.3":
+  version: 0.10.4
+  resolution: "util@npm:0.10.4"
+  dependencies:
+    inherits: "npm:2.0.3"
+  checksum: 10c0/d29f6893e406b63b088ce9924da03201df89b31490d4d011f1c07a386ea4b3dbe907464c274023c237da470258e1805d806c7e4009a5974cd6b1d474b675852a
+  languageName: node
+  linkType: hard
+
 "vary@npm:^1.1.2":
   version: 1.1.2
   resolution: "vary@npm:1.1.2"