diff --git a/app/api/client.ts b/app/api/client.ts
index 92d6e13..338b348 100644
--- a/app/api/client.ts
+++ b/app/api/client.ts
@@ -1,4 +1,4 @@
-interface paths {
+interface get {
   "/item": {
     parameters: {
       query: {
@@ -11,12 +11,56 @@ interface paths {
     parameters: {
       query?: never;
     };
+    return?: Array<Item>;
+  };
+  "/case": {
+    parameters: {
+      query: {
+        uuid: string;
+      };
+    };
+    return: Case;
+  };
+  "/cases": {
+    parameters: {
+      query?: never;
+    };
+    return?: Array<Case>;
+  };
+}
+
+interface post {
+  "/login": {
+    parameters: {
+      query?: never;
+      body: {
+        username: string;
+        password: string;
+      };
+    };
+    return: User;
+  };
+  "/logout": {
+    parameters: {
+      query?: never;
+      body?: never;
+    };
+    return?: never;
+  };
+  "/register": {
+    parameters: {
+      query?: never;
+      body: {
+        username: string;
+        password: string;
+        email: string;
+      };
+    };
     return?: never;
   };
 }
 
 export interface Item {
-  id: number;
   uuid: string;
   name: string;
   rarity: number;
@@ -24,6 +68,18 @@ export interface Item {
   image: string;
 }
 
+export interface Case {
+  uuid: string;
+  name: string;
+  price: number;
+  image: string;
+}
+
+export interface User {
+  uuid: string;
+  username: string;
+}
+
 class Client {
   baseUrl: string;
 
@@ -31,20 +87,44 @@ class Client {
     this.baseUrl = baseUrl;
   }
 
-  GET<T extends keyof paths>(
+  async GET<T extends keyof get>(
     path: T,
-    parameters: paths[T]["parameters"]
-  ): Promise<paths[T]["return"]> {
+    parameters: get[T]["parameters"]
+  ): Promise<[get[T]["return"], number]> {
     let query = parameters["query"]
       ? "?" + new URLSearchParams(parameters["query"])
       : "";
-    return fetch(this.baseUrl + path + query, {
+    let response = await fetch(this.baseUrl + path + query, {
       method: "GET",
       headers: {
         "Content-Type": "application/json",
       },
-      // body: parameters ? JSON.stringify(parameters) : undefined,
-    }).then((response) => response.json());
+    });
+    let data = await response.json();
+    return [data, response.status];
+  }
+
+  async POST<T extends keyof post>(
+    path: T,
+    parameters: post[T]["parameters"]
+  ): Promise<[post[T]["return"], number]> {
+    let query = parameters["query"]
+      ? "?" + new URLSearchParams(parameters["query"])
+      : "";
+    let response = await fetch(this.baseUrl + path + query, {
+      method: "POST",
+      body: JSON.stringify(parameters["body"]),
+      headers: {
+        "Content-Type": "application/json",
+      },
+    });
+    let data;
+    try {
+      data = await response.json();
+    } catch (_) {
+      data = null;
+    }
+    return [data, response.status];
   }
 }