Ky quick start

Install Ky, send a JSON request with a custom header, and read the JSON response body.

Ky is an HTTP client based on the Fetch API: pass a URL and options, then use a method shortcut and a body method to make a request and read its response.

Prerequisites

Ky targets modern browsers, Node.js, Bun, and Deno. The package requires Node.js 22 or newer.

Install

bash
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npm install ky

Send a JSON request

1. Import the default ky export. Use json for the request body and headers for the custom request header. The post() shortcut sends a POST request; json() reads and parses the response body.

   ts
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   import ky from 'ky';
   
   const main = async (): Promise<void> => {
     const result = await ky.post('https://httpbin.org/anything', {
       json: {name: 'Ada'},
       headers: {
         'x-client': 'ky-quick-start',
       },
     }).json();
   
     console.log(result);
   };
   
   void main();
   

   Inspect result in the console to see the parsed JSON response body. Its type is unknown by default; use a type argument when you know the response shape, or validate the response as described in Send and read JSON.

What you have

Your code sends a POST request with a JSON body and the x-client header, then logs the parsed response body. Ky sets the JSON content type for the json option unless you provide a Content-Type header yourself. A non-2xx response throws an HTTPError by default, and .json() also throws if the response body is empty.

Where to go next

• Send and read JSON for response typing and JSON handling.
• Add request headers for reusable headers.
• How Ky works for the core concepts.