diff --git a/src/class_library_client.ts b/src/class_library_client.ts
new file mode 100644
index 0000000..6812ca4
--- /dev/null
+++ b/src/class_library_client.ts
@@ -0,0 +1,83 @@
+// https://gist.github.com/didiercrunch/8fbe1e26595e41817c92bed4efc44bcd
+import {Book} from "./library_server.ts"
+
+class LibraryClient{
+    host: string;
+    constructor(host: string) {
+        this.host = host;
+    }
+
+
+    async getPing(): Promise<void> {
+        const resp = await fetch(this.host + "/ping")
+        const text = await resp.text()
+        console.log(text)
+    }
+
+    extractIsbn(rawResponse: any): string[]{
+        const ret: string[] = [];
+        for(const elm of rawResponse.books){
+            ret.push(elm.isbn)
+        }
+        return ret;
+    }
+
+    async getAllIsbn(): Promise<string[]>{
+        const resp = await fetch(this.host + "/books");
+        const ret = await resp.json();
+        return this.extractIsbn(ret);
+
+    }
+
+    async createBook(isbn: string,
+                              author: string,
+                              title: string,
+                              publicationYear: number): Promise<boolean>{
+        const book = {isbn: isbn, author: author, title: title, publicationYear: publicationYear};
+
+        const resp = await fetch(this.host + "/books", {
+            method: "POST",
+            headers: {
+                "Content-Type": "application/json",
+            },
+            body: JSON.stringify(book),
+        });
+        return resp.status < 300 && resp.status > 199;
+    }
+
+    async createFourBooks(): Promise<void>{
+        await this.createBook("0000", "jk rolling", "harry potter I", 2004);
+        await this.createBook("1111", "jk rolling", "harry potter II", 2005);
+        await this.createBook("2222", "jk rolling", "harry potter III", 2006);
+        await this.createBook("3333", "jk rolling", "harry potter IV", 2007);
+    }
+
+    async getBook(isbn: string): Promise<Book>{
+        const url = this.host + "/books/" + isbn;
+        const resp = await fetch(url);
+        const ret = await resp.json();
+        return ret;
+
+    }
+
+    async  getBookByAuthor(author: string): Promise<string[]>{
+        const urlParams =  new URLSearchParams({
+            author: author,
+        });
+
+        const url = this.host + "/books?" + urlParams;
+        const resp = await fetch(url);
+        const ret = await resp.json();
+        return this.extractIsbn(ret);
+    }
+
+}
+
+
+
+
+const client = new LibraryClient("http://localhost:3000");
+await client.createFourBooks();
+console.log(await client.getBookByAuthor("jk rolling"))
+
+