undici

An HTTP/1.1 client, written from scratch for Node.js.

Undici means eleven in Italian. 1.1 -> 11 -> Eleven -> Undici. It is also a Stranger Things reference.

Install

npm i undici

API

new undici.Client(url, opts)

A basic HTTP/1.1 client, mapped on top a single TCP/TLS connection. Keepalive is enabled by default, and it cannot be turned off.

The url will be used to extract the protocol and the domain/IP address. The path is discarded.

Options:

• timeout, the timeout after which a request will time out, in milliseconds. Default: 30000 milliseconds.

• pipelining, the amount of concurrent requests to be sent over the single TCP/TLS connection according to RFC7230. Default: 1.

client.request(opts, cb(err, data))

Performs an HTTP request.

Options:

• path
• method
• body, it can be a String, a Buffer or a stream.Readable.
• headers, an object with header-value pairs.

Headers are represented by an object like this:

{
  'content-length': '123',
  'content-type': 'text/plain',
  connection: 'keep-alive',
  host: 'mysite.com',
  accept: '*/*'
}

Keys are lowercased. Values are not modified. If you don't specify a host header, it will be derived from the url of the client instance.

The data parameter in the callback is defined as follow:

• statusCode
• headers
• body, a stream.Readable with the body to read. A user must call data.body.resume()

Example:

const { Client } = require('undici')
const client = new Client(`http://localhost:3000`)

client.request({
  path: '/',
  method: 'GET'
}, function (err, data) {
  if (err) {
    // handle this in some way!
    return
  }
  const {
    statusCode,
    headers,
    body
  } = data


  console.log('response received', statusCode)
  console.log('headers', headers)

  body.setEncoding('utf8')
  body.on('data', console.log)

  client.close()
})

Promises and async await are supported as well!

const { statusCode, headers, body } = await client.request({
  path: '/',
  method: 'GET'
})

client.pipelining

Property to set the pipelining factor.

client.full

True if the number of requests waiting to be sent is greater than the pipelining factor. Keeping a client full ensures that once the inflight set of requests finishes there is a full batch ready to go.

client.close()

Close the client as soon as all the enqueued requests are completed

client.destroy(err)

Destroy the client abruptly with the given err. All the current and enqueued requests will error.

Events

• 'drain', emitted when the queue is empty.

undici.Pool

A pool of Client connected to the same upstream target. A pool creates a fixed number of Client

Options:

• connections, the number of clients to create. Default 100.
• pipelining, the pipelining factor. Default 1.
• timeout, the timeout for each request. Default 30000 milliseconds.

pool.request(req, cb)

Calls client.request(req, cb) on one of the clients.

pool.close()

Calls client.close() on all the clients.

pool.destroy()

Calls client.destroy() on all the clients.

License

MIT