diff --git a/catDataMocking/src/app.ts b/catDataMocking/src/app.ts
index 8736715..e9d358a 100644
--- a/catDataMocking/src/app.ts
+++ b/catDataMocking/src/app.ts
@@ -8,29 +8,63 @@ const port: number = 8000;
 
 app.use(cors());
 
-// 전체 적용
+// * Logging Middleware
 app.use((req, res, next) => {
   console.log(req.rawHeaders[1]);
   next();
 });
 
-// 특정 REST 엔드포인트 적용
-app.get("/cats/blue", (req, res) => {
-  console.log("This is /cats/blue GET middleware");
-});
+// * json middleware
+app.use(express.json());
 
-app.get("/", (req: express.Request, res: express.Response) => {
-  res.send({ cats: Cat });
+// * C
+app.post("/cats", (req, res) => {
+  try {
+    const data = req.body;
+    Cat.push(data);
+    res.status(200).send({
+      success: true,
+      data: { data },
+    });
+  } catch (error) {}
 });
 
-app.get("/cats/blue", (req, res) => {
-  res.send({ blue: Cat[0] });
+// * R
+app.get("/cats", (req, res) => {
+  try {
+    const cats = Cat;
+    res.status(200).send({
+      success: true,
+      data: { cats },
+    });
+  } catch (error) {
+    res.status(400).send({
+      success: false,
+      error: error.message,
+    });
+  }
 });
-app.get("/cats/som", (req, res) => {
-  res.send({ som: Cat[1] });
+
+app.get("/cats/:id", (req, res) => {
+  try {
+    const params = req.params;
+    const cats = Cat.find((cat) => {
+      return cat.id === params.id;
+    });
+    if (!cats) throw new Error("no matched data");
+    res.status(200).send({
+      success: true,
+      data: { cats },
+    });
+  } catch (error) {
+    res.status(400).send({
+      success: false,
+      error: error.message,
+    });
+  }
 });
 
-// not found
+// * 404 middleware
 app.use((req, res, next) => {
   console.log(req.rawHeaders[1]);
   console.log("This is 404 middleware");