JavaScript
Tiny and elegant HTTP client based on the browser Fetch API

Ky is a tiny and elegant HTTP client based on the browser Fetch API

Ky targets modern browsers. For older browsers, you will need to transpile and use a fetch polyfill. For Node.js, check out Got.

1 KB (minified & gzipped), one file, and no dependencies.

Benefits over plain fetch

• Simpler API
• Method shortcuts (ky.post())
• Treats non-200 status codes as errors
• Retries failed requests
• JSON option
• Timeout support
• Instances with custom defaults

Install

$ npm install ky

Usage

import ky from 'ky';

(async () => {
	const json = await ky.post('https://some-api.com', {json: {foo: true}}).json();

	console.log(json);
	//=> `{data: '🦄'}`
})();

With plain fetch, it would be:

(async () => {
	class HTTPError extends Error {}

	const response = await fetch('https://sindresorhus.com', {
		method: 'POST',
		body: JSON.stringify({foo: true}),
		headers: {
			'content-type': 'application/json'
		}
	});

	if (!response.ok) {
		throw new HTTPError(`Fetch error:`, response.statusText);
	}

	const json = await response.json();

	console.log(json);
	//=> `{data: '🦄'}`
})();

API

ky(input, [options])

The input and options are the same as fetch, with some exceptions:

• The credentials option is same-origin by default, which is the default in the spec too, but not all browsers have caught up yet.
• Adds some more options. See below.

Returns a Response object with Body methods added for convenience. So you can, for example, call ky.json() directly on the Response without having to await it first. Unlike the Body methods of window.Fetch; these will throw an HTTPError if the response status is not in the range 200...299.

options

Type: Object

json

Type: Object

Shortcut for sending JSON. Use this instead of the body option. Accepts a plain object which will be JSON.stringify()'d and the correct header will be set for you.

ky.get(input, [options])

ky.post(input, [options])

ky.put(input, [options])

ky.patch(input, [options])

ky.head(input, [options])

ky.delete(input, [options])

Sets options.method to the method name and makes a request.

retry

Type: number
Default: 2

Retry failed requests made with one of the below methods that result in a network error or one of the below status codes.

Methods: GET PUT HEAD DELETE OPTIONS TRACE
Status codes: 408 413 429 500 502 503 504

timeout

Type: number
Default: 10000

Timeout in milliseconds for getting a response.

ky.extend(defaultOptions)

Create a new ky instance with some defaults overridden with your own.

defaultOptions

Type: Object

ky.HTTPError

Exposed for instanceof checks. The error has a response property with the Response object.

ky.TimeoutError

The error thrown when the request times out.

Tips

Cancelation

Fetch (and hence Ky) has built-in support for request cancelation through the AbortController API. Read more.

Example:

import ky from 'ky';

const controller = new AbortController();
const {signal} = controller;

setTimeout(() => controller.abort(), 5000);

(async () => {
	try {
		console.log(await ky(url, {signal}).text());
	} catch (error) {
		if (error.name === 'AbortError') {
		  console.log('Fetch aborted');
		} else {
		  console.error('Fetch error:', error);
		}
	}
})();

FAQ

How is it different from r2?

See my answer in #10.

Browser support

The latest version of Chrome, Firefox, and Safari.

Related

• got - Simplified HTTP requests for Node.js

License

MIT © Sindre Sorhus