Research
Security News
Threat Actor Exposes Playbook for Exploiting npm to Build Blockchain-Powered Botnets
A threat actor's playbook for exploiting the npm ecosystem was exposed on the dark web, detailing how to build a blockchain-powered botnet.
node-fetch
Advanced tools
The node-fetch package is a light-weight module that brings window.fetch to Node.js. It is designed to provide a fetch-first, URL-friendly way to access resources across the network.
Simple GET Request
This code performs a simple GET request to the GitHub API and logs the response data.
const fetch = require('node-fetch');
fetch('https://api.github.com/users/github')
.then(response => response.json())
.then(data => console.log(data));
POST Request with JSON
This code sends a POST request with a JSON body to httpbin.org and logs the response JSON.
const fetch = require('node-fetch');
fetch('https://httpbin.org/post', {
method: 'post',
body: JSON.stringify({foo: 'bar'}),
headers: { 'Content-Type': 'application/json' },
})
.then(res => res.json())
.then(json => console.log(json));
Handling Network Errors
This code attempts to fetch a resource from an invalid domain and catches network errors.
const fetch = require('node-fetch');
fetch('https://domain.invalid')
.catch(err => console.error('Network error:', err));
Stream Response
This code fetches an image from GitHub and streams it to a file.
const fetch = require('node-fetch');
const fs = require('fs');
fetch('https://assets-cdn.github.com/images/modules/logos_page/Octocat.png')
.then(res => {
const dest = fs.createWriteStream('./octocat.png');
res.body.pipe(dest);
});
Axios is a promise-based HTTP client for the browser and Node.js. It supports interceptors, request/response transformations, and automatic transforms for JSON data. Axios is often considered more feature-rich than node-fetch, with built-in support for interceptors and a wider range of HTTP request methods.
Got is a human-friendly and powerful HTTP request library for Node.js. It provides a simpler and more comprehensive API than node-fetch, with features like retries, pagination, and streams. Got is designed to be a more robust and versatile alternative to node-fetch, with additional convenience methods and options.
Superagent is a small progressive client-side HTTP request library, and Node.js module with the same API, sporting many high-level HTTP client features. Compared to node-fetch, Superagent offers a more fluent and flexible API, with methods for building queries and handling responses in a more expressive way.
Request is a simplified HTTP request client for Node.js, which has been deprecated. It was known for its simplicity and wide adoption but has been replaced by more modern libraries like node-fetch. Despite its deprecation, it was once a popular alternative with a callback-based API.
A light-weight module that brings window.fetch
to Node.js
(We are looking for v2 maintainers and collaborators)
Instead of implementing XMLHttpRequest
in Node.js to run browser-specific Fetch polyfill, why not go from native http
to fetch
API directly? Hence, node-fetch
, minimal code for a window.fetch
compatible API on Node.js runtime.
See Matt Andrews' isomorphic-fetch or Leonardo Quixada's cross-fetch for isomorphic usage (exports node-fetch
for server-side, whatwg-fetch
for client-side).
window.fetch
API.res.text()
and res.json()
) to UTF-8 automatically.window.fetch
offers, feel free to open an issue.Current stable release (2.x
)
$ npm install node-fetch
We suggest you load the module via require
until the stabilization of ES modules in node:
const fetch = require('node-fetch');
If you are using a Promise library other than native, set it through fetch.Promise
:
const Bluebird = require('bluebird');
fetch.Promise = Bluebird;
NOTE: The documentation below is up-to-date with 2.x
releases; see the 1.x
readme, changelog and 2.x upgrade guide for the differences.
fetch('https://github.com/')
.then(res => res.text())
.then(body => console.log(body));
fetch('https://api.github.com/users/github')
.then(res => res.json())
.then(json => console.log(json));
fetch('https://httpbin.org/post', { method: 'POST', body: 'a=1' })
.then(res => res.json()) // expecting a json response
.then(json => console.log(json));
const body = { a: 1 };
fetch('https://httpbin.org/post', {
method: 'post',
body: JSON.stringify(body),
headers: { 'Content-Type': 'application/json' },
})
.then(res => res.json())
.then(json => console.log(json));
URLSearchParams
is available in Node.js as of v7.5.0. See official documentation for more usage methods.
NOTE: The Content-Type
header is only set automatically to x-www-form-urlencoded
when an instance of URLSearchParams
is given as such:
const { URLSearchParams } = require('url');
const params = new URLSearchParams();
params.append('a', 1);
fetch('https://httpbin.org/post', { method: 'POST', body: params })
.then(res => res.json())
.then(json => console.log(json));
NOTE: 3xx-5xx responses are NOT exceptions and should be handled in then()
; see the next section for more information.
Adding a catch to the fetch promise chain will catch all exceptions, such as errors originating from node core libraries, network errors and operational errors, which are instances of FetchError. See the error handling document for more details.
fetch('https://domain.invalid/')
.catch(err => console.error(err));
It is common to create a helper function to check that the response contains no client (4xx) or server (5xx) error responses:
function checkStatus(res) {
if (res.ok) { // res.status >= 200 && res.status < 300
return res;
} else {
throw MyCustomError(res.statusText);
}
}
fetch('https://httpbin.org/status/400')
.then(checkStatus)
.then(res => console.log('will not get here...'))
The "Node.js way" is to use streams when possible:
fetch('https://assets-cdn.github.com/images/modules/logos_page/Octocat.png')
.then(res => {
const dest = fs.createWriteStream('./octocat.png');
res.body.pipe(dest);
});
In Node.js 14 you can also use async iterators to read body
; however, be careful to catch
errors -- the longer a response runs, the more likely it is to encounter an error.
const fetch = require('node-fetch');
const response = await fetch('https://httpbin.org/stream/3');
try {
for await (const chunk of response.body) {
console.dir(JSON.parse(chunk.toString()));
}
} catch (err) {
console.error(err.stack);
}
In Node.js 12 you can also use async iterators to read body
; however, async iterators with streams
did not mature until Node.js 14, so you need to do some extra work to ensure you handle errors
directly from the stream and wait on it response to fully close.
const fetch = require('node-fetch');
const read = async body => {
let error;
body.on('error', err => {
error = err;
});
for await (const chunk of body) {
console.dir(JSON.parse(chunk.toString()));
}
return new Promise((resolve, reject) => {
body.on('close', () => {
error ? reject(error) : resolve();
});
});
};
try {
const response = await fetch('https://httpbin.org/stream/3');
await read(response.body);
} catch (err) {
console.error(err.stack);
}
If you prefer to cache binary data in full, use buffer(). (NOTE: buffer()
is a node-fetch
-only API)
const fileType = require('file-type');
fetch('https://assets-cdn.github.com/images/modules/logos_page/Octocat.png')
.then(res => res.buffer())
.then(buffer => fileType(buffer))
.then(type => { /* ... */ });
fetch('https://github.com/')
.then(res => {
console.log(res.ok);
console.log(res.status);
console.log(res.statusText);
console.log(res.headers.raw());
console.log(res.headers.get('content-type'));
});
Unlike browsers, you can access raw Set-Cookie
headers manually using Headers.raw()
. This is a node-fetch
only API.
fetch(url).then(res => {
// returns an array of values, instead of a string of comma-separated values
console.log(res.headers.raw()['set-cookie']);
});
const { createReadStream } = require('fs');
const stream = createReadStream('input.txt');
fetch('https://httpbin.org/post', { method: 'POST', body: stream })
.then(res => res.json())
.then(json => console.log(json));
const FormData = require('form-data');
const form = new FormData();
form.append('a', 1);
fetch('https://httpbin.org/post', { method: 'POST', body: form })
.then(res => res.json())
.then(json => console.log(json));
// OR, using custom headers
// NOTE: getHeaders() is non-standard API
const form = new FormData();
form.append('a', 1);
const options = {
method: 'POST',
body: form,
headers: form.getHeaders()
}
fetch('https://httpbin.org/post', options)
.then(res => res.json())
.then(json => console.log(json));
NOTE: You may cancel streamed requests only on Node >= v8.0.0
You may cancel requests with AbortController
. A suggested implementation is abort-controller
.
An example of timing out a request after 150ms could be achieved as the following:
import AbortController from 'abort-controller';
const controller = new AbortController();
const timeout = setTimeout(
() => { controller.abort(); },
150,
);
fetch(url, { signal: controller.signal })
.then(res => res.json())
.then(
data => {
useData(data)
},
err => {
if (err.name === 'AbortError') {
// request was aborted
}
},
)
.finally(() => {
clearTimeout(timeout);
});
See test cases for more examples.
url
A string representing the URL for fetchingoptions
Options for the HTTP(S) requestPromise<Response>
Perform an HTTP(S) fetch.
url
should be an absolute url, such as https://example.com/
. A path-relative URL (/file/under/root
) or protocol-relative URL (//can-be-http-or-https.com/
) will result in a rejected Promise
.
The default values are shown after each option key.
{
// These properties are part of the Fetch Standard
method: 'GET',
headers: {}, // request headers. format is the identical to that accepted by the Headers constructor (see below)
body: null, // request body. can be null, a string, a Buffer, a Blob, or a Node.js Readable stream
redirect: 'follow', // set to `manual` to extract redirect headers, `error` to reject redirect
signal: null, // pass an instance of AbortSignal to optionally abort requests
// The following properties are node-fetch extensions
follow: 20, // maximum redirect count. 0 to not follow redirect
timeout: 0, // req/res timeout in ms, it resets on redirect. 0 to disable (OS limit applies). Signal is recommended instead.
compress: true, // support gzip/deflate content encoding. false to disable
size: 0, // maximum response body size in bytes. 0 to disable
agent: null // http(s).Agent instance or function that returns an instance (see below)
}
If no values are set, the following request headers will be sent automatically:
Header | Value |
---|---|
Accept-Encoding | gzip,deflate (when options.compress === true ) |
Accept | */* |
Content-Length | (automatically calculated, if possible) |
Transfer-Encoding | chunked (when req.body is a stream) |
User-Agent | node-fetch/1.0 (+https://github.com/bitinn/node-fetch) |
Note: when body
is a Stream
, Content-Length
is not set automatically.
The agent
option allows you to specify networking related options which are out of the scope of Fetch, including and not limited to the following:
See http.Agent
for more information.
If no agent is specified, the default agent provided by Node.js is used. Note that this changed in Node.js 19 to have keepalive
true by default. If you wish to enable keepalive
in an earlier version of Node.js, you can override the agent as per the following code sample.
In addition, the agent
option accepts a function that returns http
(s).Agent
instance given current URL, this is useful during a redirection chain across HTTP and HTTPS protocol.
const httpAgent = new http.Agent({
keepAlive: true
});
const httpsAgent = new https.Agent({
keepAlive: true
});
const options = {
agent: function (_parsedURL) {
if (_parsedURL.protocol == 'http:') {
return httpAgent;
} else {
return httpsAgent;
}
}
}
An HTTP(S) request containing information about URL, method, headers, and the body. This class implements the Body interface.
Due to the nature of Node.js, the following properties are not implemented at this moment:
type
destination
referrer
referrerPolicy
mode
credentials
cache
integrity
keepalive
The following node-fetch extension properties are provided:
follow
compress
counter
agent
See options for exact meaning of these extensions.
(spec-compliant)
input
A string representing a URL, or another Request
(which will be cloned)options
[Options][#fetch-options] for the HTTP(S) requestConstructs a new Request
object. The constructor is identical to that in the browser.
In most cases, directly fetch(url, options)
is simpler than creating a Request
object.
An HTTP(S) response. This class implements the Body interface.
The following properties are not implemented in node-fetch at this moment:
Response.error()
Response.redirect()
type
trailer
(spec-compliant)
body
A String
or Readable
streamoptions
A ResponseInit
options dictionaryConstructs a new Response
object. The constructor is identical to that in the browser.
Because Node.js does not implement service workers (for which this class was designed), one rarely has to construct a Response
directly.
(spec-compliant)
Convenience property representing if the request ended normally. Will evaluate to true if the response status was greater than or equal to 200 but smaller than 300.
(spec-compliant)
Convenience property representing if the request has been redirected at least once. Will evaluate to true if the internal redirect counter is greater than 0.
This class allows manipulating and iterating over a set of HTTP headers. All methods specified in the Fetch Standard are implemented.
(spec-compliant)
init
Optional argument to pre-fill the Headers
objectConstruct a new Headers
object. init
can be either null
, a Headers
object, an key-value map object or any iterable object.
// Example adapted from https://fetch.spec.whatwg.org/#example-headers-class
const meta = {
'Content-Type': 'text/xml',
'Breaking-Bad': '<3'
};
const headers = new Headers(meta);
// The above is equivalent to
const meta = [
[ 'Content-Type', 'text/xml' ],
[ 'Breaking-Bad', '<3' ]
];
const headers = new Headers(meta);
// You can in fact use any iterable objects, like a Map or even another Headers
const meta = new Map();
meta.set('Content-Type', 'text/xml');
meta.set('Breaking-Bad', '<3');
const headers = new Headers(meta);
const copyOfHeaders = new Headers(headers);
Body
is an abstract interface with methods that are applicable to both Request
and Response
classes.
The following methods are not yet implemented in node-fetch at this moment:
formData()
(deviation from spec)
Readable
streamData are encapsulated in the Body
object. Note that while the Fetch Standard requires the property to always be a WHATWG ReadableStream
, in node-fetch it is a Node.js Readable
stream.
(spec-compliant)
Boolean
A boolean property for if this body has been consumed. Per the specs, a consumed body cannot be used again.
(spec-compliant)
Promise
Consume the body and return a promise that will resolve to one of these formats.
(node-fetch extension)
Promise<Buffer>
Consume the body and return a promise that will resolve to a Buffer.
(node-fetch extension)
Promise<String>
Identical to body.text()
, except instead of always converting to UTF-8, encoding sniffing will be performed and text converted to UTF-8 if possible.
(This API requires an optional dependency of the npm package encoding, which you need to install manually. webpack
users may see a warning message due to this optional dependency.)
(node-fetch extension)
An operational error in the fetching process. See ERROR-HANDLING.md for more info.
(node-fetch extension)
An Error thrown when the request is aborted in response to an AbortSignal
's abort
event. It has a name
property of AbortError
. See ERROR-HANDLING.MD for more info.
Thanks to github/fetch for providing a solid implementation reference.
node-fetch
v1 was maintained by @bitinn; v2 was maintained by @TimothyGu, @bitinn and @jimmywarting; v2 readme is written by @jkantr.
MIT
FAQs
A light-weight module that brings Fetch API to node.js
The npm package node-fetch receives a total of 0 weekly downloads. As such, node-fetch popularity was classified as not popular.
We found that node-fetch demonstrated a not healthy version release cadence and project activity because the last version was released a year ago. It has 5 open source maintainers collaborating on the project.
Did you know?
Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.
Research
Security News
A threat actor's playbook for exploiting the npm ecosystem was exposed on the dark web, detailing how to build a blockchain-powered botnet.
Security News
NVD’s backlog surpasses 20,000 CVEs as analysis slows and NIST announces new system updates to address ongoing delays.
Security News
Research
A malicious npm package disguised as a WhatsApp client is exploiting authentication flows with a remote kill switch to exfiltrate data and destroy files.