HTTP method used to make the request.

Internally, the standard methods (`GET`, `POST`, `PUT`, `PATCH`, `HEAD` and `DELETE`) are uppercased in order to avoid server errors due to case sensitivity.

HTTP headers used to make the request.

You can pass a `Headers` instance or a plain object.

You can remove a header with `.extend()` by passing the header with an `undefined` value.

Shortcut for sending JSON. Use this instead of the body option.

Accepts any plain object or value, which will be `JSON.stringify()`'d and sent in the body with the correct header set.

User-defined JSON-parsing function.

Use-cases:
1. Parse JSON via the [`bourne` package](https://github.com/hapijs/bourne) to protect from prototype pollution.
2. Parse JSON with [`reviver` option of `JSON.parse()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse).

Search parameters to include in the request URL. Setting this will override all existing search parameters in the input URL.

Accepts any value supported by [`URLSearchParams()`](https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams/URLSearchParams).

A prefix to prepend to the input URL when making the request. It can be any valid URL, either relative or absolute. A trailing slash / is optional and will be added automatically, if needed, when it is joined with input. Only takes effect when input is a string. The input argument cannot start with a slash / when using this option.

Useful when used with [`ky.extend()`](#kyextenddefaultoptions) to create niche-specific Ky-instances.

Notes:
 - After `prefixUrl` and `input` are joined, the result is resolved against the [base URL](https://developer.mozilla.org/en-US/docs/Web/API/Node/baseURI) of the page (if any).
 - Leading slashes in `input` are disallowed when using this option to enforce consistency and avoid confusion about how the `input` URL is handled, given that `input` will not follow the normal URL resolution rules when `prefixUrl` is being used, which changes the meaning of a leading slash.

An object representing limit, methods, statusCodes and maxRetryAfter fields for maximum retry count, allowed methods, allowed status codes and maximum Retry-After time.

If `retry` is a number, it will be used as `limit` and other defaults will remain in place.

If `maxRetryAfter` is set to `undefined`, it will use `options.timeout`. If [`Retry-After`](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Retry-After) header is greater than `maxRetryAfter`, it will cancel the request.

Delays between retries is calculated with the function `0.3(2 ** (retry - 1)) * 1000`, where `retry` is the attempt number (starts from 1).

Retries are not triggered following a timeout.

Timeout in milliseconds for getting a response, including any retries. Can not be greater than 2147483647. If set to false, there will be no timeout.

Hooks allow modifications during the request lifecycle. Hook functions may be async and are run serially.

Throw an HTTPError when, after following redirects, the response has a non-2xx status code. To also throw for redirects instead of following them, set the redirect option to 'manual'.

Setting this to `false` may be useful if you are checking for resource availability and are expecting error responses.

Note: If `false`, error responses are considered successful and the request will not be retried.

Download progress event handler.

User-defined fetch function. Has to be fully compatible with the Fetch API standard.

Use-cases:
1. Use custom `fetch` implementations like [`isomorphic-unfetch`](https://www.npmjs.com/package/isomorphic-unfetch).
2. Use the `fetch` wrapper function provided by some frameworks that use server-side rendering (SSR).