Adding upstream version 5.28.2+dfsg1+~cs23.11.12.3.upstream/5.28.2+dfsg1+_cs23.11.12.3upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

27 files changed, 3961 insertions, 0 deletions

diff --git a/docs/api/Agent.md b/docs/api/Agent.md
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+# Agent
+
+Extends: `undici.Dispatcher`
+
+Agent allow dispatching requests against multiple different origins.
+
+Requests are not guaranteed to be dispatched in order of invocation.
+
+## `new undici.Agent([options])`
+
+Arguments:
+
+* **options** `AgentOptions` (optional)
+
+Returns: `Agent`
+
+### Parameter: `AgentOptions`
+
+Extends: [`PoolOptions`](Pool.md#parameter-pooloptions)
+
+* **factory** `(origin: URL, opts: Object) => Dispatcher` - Default: `(origin, opts) => new Pool(origin, opts)`
+* **maxRedirections** `Integer` - Default: `0`. The number of HTTP redirection to follow unless otherwise specified in `DispatchOptions`.
+* **interceptors** `{ Agent: DispatchInterceptor[] }` - Default: `[RedirectInterceptor]` - A list of interceptors that are applied to the dispatch method. Additional logic can be applied (such as, but not limited to: 302 status code handling, authentication, cookies, compression and caching). Note that the behavior of interceptors is Experimental and might change at any given time.
+
+## Instance Properties
+
+### `Agent.closed`
+
+Implements [Client.closed](Client.md#clientclosed)
+
+### `Agent.destroyed`
+
+Implements [Client.destroyed](Client.md#clientdestroyed)
+
+## Instance Methods
+
+### `Agent.close([callback])`
+
+Implements [`Dispatcher.close([callback])`](Dispatcher.md#dispatcherclosecallback-promise).
+
+### `Agent.destroy([error, callback])`
+
+Implements [`Dispatcher.destroy([error, callback])`](Dispatcher.md#dispatcherdestroyerror-callback-promise).
+
+### `Agent.dispatch(options, handler: AgentDispatchOptions)`
+
+Implements [`Dispatcher.dispatch(options, handler)`](Dispatcher.md#dispatcherdispatchoptions-handler).
+
+#### Parameter: `AgentDispatchOptions`
+
+Extends: [`DispatchOptions`](Dispatcher.md#parameter-dispatchoptions)
+
+* **origin** `string | URL`
+* **maxRedirections** `Integer`.
+
+Implements [`Dispatcher.destroy([error, callback])`](Dispatcher.md#dispatcherdestroyerror-callback-promise).
+
+### `Agent.connect(options[, callback])`
+
+See [`Dispatcher.connect(options[, callback])`](Dispatcher.md#dispatcherconnectoptions-callback).
+
+### `Agent.dispatch(options, handler)`
+
+Implements [`Dispatcher.dispatch(options, handler)`](Dispatcher.md#dispatcherdispatchoptions-handler).
+
+### `Agent.pipeline(options, handler)`
+
+See [`Dispatcher.pipeline(options, handler)`](Dispatcher.md#dispatcherpipelineoptions-handler).
+
+### `Agent.request(options[, callback])`
+
+See [`Dispatcher.request(options [, callback])`](Dispatcher.md#dispatcherrequestoptions-callback).
+
+### `Agent.stream(options, factory[, callback])`
+
+See [`Dispatcher.stream(options, factory[, callback])`](Dispatcher.md#dispatcherstreamoptions-factory-callback).
+
+### `Agent.upgrade(options[, callback])`
+
+See [`Dispatcher.upgrade(options[, callback])`](Dispatcher.md#dispatcherupgradeoptions-callback).
diff --git a/docs/api/BalancedPool.md b/docs/api/BalancedPool.md
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+++ b/docs/api/BalancedPool.md
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+# Class: BalancedPool
+
+Extends: `undici.Dispatcher`
+
+A pool of [Pool](Pool.md) instances connected to multiple upstreams.
+
+Requests are not guaranteed to be dispatched in order of invocation.
+
+## `new BalancedPool(upstreams [, options])`
+
+Arguments:
+
+* **upstreams** `URL | string | string[]` - It should only include the **protocol, hostname, and port**.
+* **options** `BalancedPoolOptions` (optional)
+
+### Parameter: `BalancedPoolOptions`
+
+Extends: [`PoolOptions`](Pool.md#parameter-pooloptions)
+
+* **factory** `(origin: URL, opts: Object) => Dispatcher` - Default: `(origin, opts) => new Pool(origin, opts)`
+
+The `PoolOptions` are passed to each of the `Pool` instances being created.
+## Instance Properties
+
+### `BalancedPool.upstreams`
+
+Returns an array of upstreams that were previously added.
+
+### `BalancedPool.closed`
+
+Implements [Client.closed](Client.md#clientclosed)
+
+### `BalancedPool.destroyed`
+
+Implements [Client.destroyed](Client.md#clientdestroyed)
+
+### `Pool.stats`
+
+Returns [`PoolStats`](PoolStats.md) instance for this pool.
+
+## Instance Methods
+
+### `BalancedPool.addUpstream(upstream)`
+
+Add an upstream.
+
+Arguments:
+
+* **upstream** `string` - It should only include the **protocol, hostname, and port**.
+
+### `BalancedPool.removeUpstream(upstream)`
+
+Removes an upstream that was previously addded.
+
+### `BalancedPool.close([callback])`
+
+Implements [`Dispatcher.close([callback])`](Dispatcher.md#dispatcherclosecallback-promise).
+
+### `BalancedPool.destroy([error, callback])`
+
+Implements [`Dispatcher.destroy([error, callback])`](Dispatcher.md#dispatcherdestroyerror-callback-promise).
+
+### `BalancedPool.connect(options[, callback])`
+
+See [`Dispatcher.connect(options[, callback])`](Dispatcher.md#dispatcherconnectoptions-callback).
+
+### `BalancedPool.dispatch(options, handlers)`
+
+Implements [`Dispatcher.dispatch(options, handlers)`](Dispatcher.md#dispatcherdispatchoptions-handler).
+
+### `BalancedPool.pipeline(options, handler)`
+
+See [`Dispatcher.pipeline(options, handler)`](Dispatcher.md#dispatcherpipelineoptions-handler).
+
+### `BalancedPool.request(options[, callback])`
+
+See [`Dispatcher.request(options [, callback])`](Dispatcher.md#dispatcherrequestoptions-callback).
+
+### `BalancedPool.stream(options, factory[, callback])`
+
+See [`Dispatcher.stream(options, factory[, callback])`](Dispatcher.md#dispatcherstreamoptions-factory-callback).
+
+### `BalancedPool.upgrade(options[, callback])`
+
+See [`Dispatcher.upgrade(options[, callback])`](Dispatcher.md#dispatcherupgradeoptions-callback).
+
+## Instance Events
+
+### Event: `'connect'`
+
+See [Dispatcher Event: `'connect'`](Dispatcher.md#event-connect).
+
+### Event: `'disconnect'`
+
+See [Dispatcher Event: `'disconnect'`](Dispatcher.md#event-disconnect).
+
+### Event: `'drain'`
+
+See [Dispatcher Event: `'drain'`](Dispatcher.md#event-drain).
diff --git a/docs/api/CacheStorage.md b/docs/api/CacheStorage.md
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+# CacheStorage
+
+Undici exposes a W3C spec-compliant implementation of [CacheStorage](https://developer.mozilla.org/en-US/docs/Web/API/CacheStorage) and [Cache](https://developer.mozilla.org/en-US/docs/Web/API/Cache).
+
+## Opening a Cache
+
+Undici exports a top-level CacheStorage instance. You can open a new Cache, or duplicate a Cache with an existing name, by using `CacheStorage.prototype.open`. If you open a Cache with the same name as an already-existing Cache, its list of cached Responses will be shared between both instances.
+
+```mjs
+import { caches } from 'undici'
+
+const cache_1 = await caches.open('v1')
+const cache_2 = await caches.open('v1')
+
+// Although .open() creates a new instance,
+assert(cache_1 !== cache_2)
+// The same Response is matched in both.
+assert.deepStrictEqual(await cache_1.match('/req'), await cache_2.match('/req'))
+```
+
+## Deleting a Cache
+
+If a Cache is deleted, the cached Responses/Requests can still be used.
+
+```mjs
+const response = await cache_1.match('/req')
+await caches.delete('v1')
+
+await response.text() // the Response's body
+```
diff --git a/docs/api/Client.md b/docs/api/Client.md
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+++ b/docs/api/Client.md
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+# Class: Client
+
+Extends: `undici.Dispatcher`
+
+A basic HTTP/1.1 client, mapped on top a single TCP/TLS connection. Pipelining is disabled by default.
+
+Requests are not guaranteed to be dispatched in order of invocation.
+
+## `new Client(url[, options])`
+
+Arguments:
+
+* **url** `URL | string` - Should only include the **protocol, hostname, and port**.
+* **options** `ClientOptions` (optional)
+
+Returns: `Client`
+
+### Parameter: `ClientOptions`
+
+> ⚠️ Warning: The `H2` support is experimental.
+
+* **bodyTimeout** `number | null` (optional) - Default: `300e3` - The timeout after which a request will time out, in milliseconds. Monitors time between receiving body data. Use `0` to disable it entirely. Defaults to 300 seconds.
+* **headersTimeout** `number | null` (optional) - Default: `300e3` - The amount of time, in milliseconds, the parser will wait to receive the complete HTTP headers while not sending the request. Defaults to 300 seconds.
+* **keepAliveMaxTimeout** `number | null` (optional) - Default: `600e3` - The maximum allowed `keepAliveTimeout`, in milliseconds, when overridden by *keep-alive* hints from the server. Defaults to 10 minutes.
+* **keepAliveTimeout** `number | null` (optional) - Default: `4e3` - The timeout, in milliseconds, after which a socket without active requests will time out. Monitors time between activity on a connected socket. This value may be overridden by *keep-alive* hints from the server. See [MDN: HTTP - Headers - Keep-Alive directives](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Keep-Alive#directives) for more details. Defaults to 4 seconds.
+* **keepAliveTimeoutThreshold** `number | null` (optional) - Default: `1e3` - A number of milliseconds subtracted from server *keep-alive* hints when overriding `keepAliveTimeout` to account for timing inaccuracies caused by e.g. transport latency. Defaults to 1 second.
+* **maxHeaderSize** `number | null` (optional) - Default: `--max-http-header-size` or `16384` - The maximum length of request headers in bytes. Defaults to Node.js' --max-http-header-size or 16KiB.
+* **maxResponseSize** `number | null` (optional) - Default: `-1` - The maximum length of response body in bytes. Set to `-1` to disable.
+* **pipelining** `number | null` (optional) - Default: `1` - The amount of concurrent requests to be sent over the single TCP/TLS connection according to [RFC7230](https://tools.ietf.org/html/rfc7230#section-6.3.2). Carefully consider your workload and environment before enabling concurrent requests as pipelining may reduce performance if used incorrectly. Pipelining is sensitive to network stack settings as well as head of line blocking caused by e.g. long running requests. Set to `0` to disable keep-alive connections.
+* **connect** `ConnectOptions | Function | null` (optional) - Default: `null`.
+* **strictContentLength** `Boolean` (optional) - Default: `true` - Whether to treat request content length mismatches as errors. If true, an error is thrown when the request content-length header doesn't match the length of the request body.
+* **interceptors** `{ Client: DispatchInterceptor[] }` - Default: `[RedirectInterceptor]` - A list of interceptors that are applied to the dispatch method. Additional logic can be applied (such as, but not limited to: 302 status code handling, authentication, cookies, compression and caching). Note that the behavior of interceptors is Experimental and might change at any given time.
+* **autoSelectFamily**: `boolean` (optional) - Default: depends on local Node version, on Node 18.13.0 and above is `false`. Enables a family autodetection algorithm that loosely implements section 5 of [RFC 8305](https://tools.ietf.org/html/rfc8305#section-5). See [here](https://nodejs.org/api/net.html#socketconnectoptions-connectlistener) for more details. This option is ignored if not supported by the current Node version.
+* **autoSelectFamilyAttemptTimeout**: `number` - Default: depends on local Node version, on Node 18.13.0 and above is `250`. The amount of time in milliseconds to wait for a connection attempt to finish before trying the next address when using the `autoSelectFamily` option. See [here](https://nodejs.org/api/net.html#socketconnectoptions-connectlistener) for more details.
+* **allowH2**: `boolean` - Default: `false`. Enables support for H2 if the server has assigned bigger priority to it through ALPN negotiation.
+* **maxConcurrentStreams**: `number` - Default: `100`. Dictates the maximum number of concurrent streams for a single H2 session. It can be overridden by a SETTINGS remote frame.
+
+#### Parameter: `ConnectOptions`
+
+Every Tls option, see [here](https://nodejs.org/api/tls.html#tls_tls_connect_options_callback).
+Furthermore, the following options can be passed:
+
+* **socketPath** `string | null` (optional) - Default: `null` - An IPC endpoint, either Unix domain socket or Windows named pipe.
+* **maxCachedSessions** `number | null` (optional) - Default: `100` - Maximum number of TLS cached sessions. Use 0 to disable TLS session caching. Default: 100.
+* **timeout** `number | null` (optional) -  In milliseconds, Default `10e3`.
+* **servername** `string | null` (optional)
+* **keepAlive** `boolean | null` (optional) - Default: `true` - TCP keep-alive enabled
+* **keepAliveInitialDelay** `number | null` (optional) - Default: `60000` - TCP keep-alive interval for the socket in milliseconds
+
+### Example - Basic Client instantiation
+
+This will instantiate the undici Client, but it will not connect to the origin until something is queued. Consider using `client.connect` to prematurely connect to the origin, or just call `client.request`.
+
+```js
+'use strict'
+import { Client } from 'undici'
+
+const client = new Client('http://localhost:3000')
+```
+
+### Example - Custom connector
+
+This will allow you to perform some additional check on the socket that will be used for the next request.
+
+```js
+'use strict'
+import { Client, buildConnector } from 'undici'
+
+const connector = buildConnector({ rejectUnauthorized: false })
+const client = new Client('https://localhost:3000', {
+  connect (opts, cb) {
+    connector(opts, (err, socket) => {
+      if (err) {
+        cb(err)
+      } else if (/* assertion */) {
+        socket.destroy()
+        cb(new Error('kaboom'))
+      } else {
+        cb(null, socket)
+      }
+    })
+  }
+})
+```
+
+## Instance Methods
+
+### `Client.close([callback])`
+
+Implements [`Dispatcher.close([callback])`](Dispatcher.md#dispatcherclosecallback-promise).
+
+### `Client.destroy([error, callback])`
+
+Implements [`Dispatcher.destroy([error, callback])`](Dispatcher.md#dispatcherdestroyerror-callback-promise).
+
+Waits until socket is closed before invoking the callback (or returning a promise if no callback is provided).
+
+### `Client.connect(options[, callback])`
+
+See [`Dispatcher.connect(options[, callback])`](Dispatcher.md#dispatcherconnectoptions-callback).
+
+### `Client.dispatch(options, handlers)`
+
+Implements [`Dispatcher.dispatch(options, handlers)`](Dispatcher.md#dispatcherdispatchoptions-handler).
+
+### `Client.pipeline(options, handler)`
+
+See [`Dispatcher.pipeline(options, handler)`](Dispatcher.md#dispatcherpipelineoptions-handler).
+
+### `Client.request(options[, callback])`
+
+See [`Dispatcher.request(options [, callback])`](Dispatcher.md#dispatcherrequestoptions-callback).
+
+### `Client.stream(options, factory[, callback])`
+
+See [`Dispatcher.stream(options, factory[, callback])`](Dispatcher.md#dispatcherstreamoptions-factory-callback).
+
+### `Client.upgrade(options[, callback])`
+
+See [`Dispatcher.upgrade(options[, callback])`](Dispatcher.md#dispatcherupgradeoptions-callback).
+
+## Instance Properties
+
+### `Client.closed`
+
+* `boolean`
+
+`true` after `client.close()` has been called.
+
+### `Client.destroyed`
+
+* `boolean`
+
+`true` after `client.destroyed()` has been called or `client.close()` has been called and the client shutdown has completed.
+
+### `Client.pipelining`
+
+* `number`
+
+Property to get and set the pipelining factor.
+
+## Instance Events
+
+### Event: `'connect'`
+
+See [Dispatcher Event: `'connect'`](Dispatcher.md#event-connect).
+
+Parameters:
+
+* **origin** `URL`
+* **targets** `Array<Dispatcher>`
+
+Emitted when a socket has been created and connected. The client will connect once `client.size > 0`.
+
+#### Example - Client connect event
+
+```js
+import { createServer } from 'http'
+import { Client } from 'undici'
+import { once } from 'events'
+
+const server = createServer((request, response) => {
+  response.end('Hello, World!')
+}).listen()
+
+await once(server, 'listening')
+
+const client = new Client(`http://localhost:${server.address().port}`)
+
+client.on('connect', (origin) => {
+  console.log(`Connected to ${origin}`) // should print before the request body statement
+})
+
+try {
+  const { body } = await client.request({
+    path: '/',
+    method: 'GET'
+  })
+  body.setEncoding('utf-8')
+  body.on('data', console.log)
+  client.close()
+  server.close()
+} catch (error) {
+  console.error(error)
+  client.close()
+  server.close()
+}
+```
+
+### Event: `'disconnect'`
+
+See [Dispatcher Event: `'disconnect'`](Dispatcher.md#event-disconnect).
+
+Parameters:
+
+* **origin** `URL`
+* **targets** `Array<Dispatcher>`
+* **error** `Error`
+
+Emitted when socket has disconnected. The error argument of the event is the error which caused the socket to disconnect. The client will reconnect if or once `client.size > 0`.
+
+#### Example - Client disconnect event
+
+```js
+import { createServer } from 'http'
+import { Client } from 'undici'
+import { once } from 'events'
+
+const server = createServer((request, response) => {
+  response.destroy()
+}).listen()
+
+await once(server, 'listening')
+
+const client = new Client(`http://localhost:${server.address().port}`)
+
+client.on('disconnect', (origin) => {
+  console.log(`Disconnected from ${origin}`)
+})
+
+try {
+  await client.request({
+    path: '/',
+    method: 'GET'
+  })
+} catch (error) {
+  console.error(error.message)
+  client.close()
+  server.close()
+}
+```
+
+### Event: `'drain'`
+
+Emitted when pipeline is no longer busy.
+
+See [Dispatcher Event: `'drain'`](Dispatcher.md#event-drain).
+
+#### Example - Client drain event
+
+```js
+import { createServer } from 'http'
+import { Client } from 'undici'
+import { once } from 'events'
+
+const server = createServer((request, response) => {
+  response.end('Hello, World!')
+}).listen()
+
+await once(server, 'listening')
+
+const client = new Client(`http://localhost:${server.address().port}`)
+
+client.on('drain', () => {
+  console.log('drain event')
+  client.close()
+  server.close()
+})
+
+const requests = [
+  client.request({ path: '/', method: 'GET' }),
+  client.request({ path: '/', method: 'GET' }),
+  client.request({ path: '/', method: 'GET' })
+]
+
+await Promise.all(requests)
+
+console.log('requests completed')
+```
+
+### Event: `'error'`
+
+Invoked for users errors such as throwing in the `onError` handler.
diff --git a/docs/api/Connector.md b/docs/api/Connector.md
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+++ b/docs/api/Connector.md
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+# Connector
+
+Undici creates the underlying socket via the connector builder.
+Normally, this happens automatically and you don't need to care about this,
+but if you need to perform some additional check over the currently used socket,
+this is the right place.
+
+If you want to create a custom connector, you must import the `buildConnector` utility.
+
+#### Parameter: `buildConnector.BuildOptions`
+
+Every Tls option, see [here](https://nodejs.org/api/tls.html#tls_tls_connect_options_callback).
+Furthermore, the following options can be passed:
+
+* **socketPath** `string | null` (optional) - Default: `null` - An IPC endpoint, either Unix domain socket or Windows named pipe.
+* **maxCachedSessions** `number | null` (optional) - Default: `100` - Maximum number of TLS cached sessions. Use 0 to disable TLS session caching. Default: `100`.
+* **timeout** `number | null` (optional) -  In milliseconds. Default `10e3`.
+* **servername** `string | null` (optional)
+
+Once you call `buildConnector`, it will return a connector function, which takes the following parameters.
+
+#### Parameter: `connector.Options`
+
+* **hostname** `string` (required)
+* **host** `string` (optional)
+* **protocol** `string` (required)
+* **port** `string` (required)
+* **servername** `string` (optional)
+* **localAddress** `string | null` (optional) Local address the socket should connect from.
+* **httpSocket** `Socket` (optional) Establish secure connection on a given socket rather than creating a new socket. It can only be sent on TLS update.
+
+### Basic example
+
+```js
+'use strict'
+
+import { Client, buildConnector } from 'undici'
+
+const connector = buildConnector({ rejectUnauthorized: false })
+const client = new Client('https://localhost:3000', {
+  connect (opts, cb) {
+    connector(opts, (err, socket) => {
+      if (err) {
+        cb(err)
+      } else if (/* assertion */) {
+        socket.destroy()
+        cb(new Error('kaboom'))
+      } else {
+        cb(null, socket)
+      }
+    })
+  }
+})
+```
+
+### Example: validate the CA fingerprint
+
+```js
+'use strict'
+
+import { Client, buildConnector } from 'undici'
+
+const caFingerprint = 'FO:OB:AR'
+const connector = buildConnector({ rejectUnauthorized: false })
+const client = new Client('https://localhost:3000', {
+  connect (opts, cb) {
+    connector(opts, (err, socket) => {
+      if (err) {
+        cb(err)
+      } else if (getIssuerCertificate(socket).fingerprint256 !== caFingerprint) {
+        socket.destroy()
+        cb(new Error('Fingerprint does not match or malformed certificate'))
+      } else {
+        cb(null, socket)
+      }
+    })
+  }
+})
+
+client.request({
+  path: '/',
+  method: 'GET'
+}, (err, data) => {
+  if (err) throw err
+
+  const bufs = []
+  data.body.on('data', (buf) => {
+    bufs.push(buf)
+  })
+  data.body.on('end', () => {
+    console.log(Buffer.concat(bufs).toString('utf8'))
+    client.close()
+  })
+})
+
+function getIssuerCertificate (socket) {
+  let certificate = socket.getPeerCertificate(true)
+  while (certificate && Object.keys(certificate).length > 0) {
+    // invalid certificate
+    if (certificate.issuerCertificate == null) {
+      return null
+    }
+
+    // We have reached the root certificate.
+    // In case of self-signed certificates, `issuerCertificate` may be a circular reference.
+    if (certificate.fingerprint256 === certificate.issuerCertificate.fingerprint256) {
+      break
+    }
+
+    // continue the loop
+    certificate = certificate.issuerCertificate
+  }
+  return certificate
+}
+```
diff --git a/docs/api/ContentType.md b/docs/api/ContentType.md
new file mode 100644
index 0000000..2bcc9f7
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+++ b/docs/api/ContentType.md
@@ -0,0 +1,57 @@
+# MIME Type Parsing
+
+## `MIMEType` interface
+
+* **type** `string`
+* **subtype** `string`
+* **parameters** `Map<string, string>`
+* **essence** `string`
+
+## `parseMIMEType(input)`
+
+Implements [parse a MIME type](https://mimesniff.spec.whatwg.org/#parse-a-mime-type).
+
+Parses a MIME type, returning its type, subtype, and any associated parameters. If the parser can't parse an input it returns the string literal `'failure'`.
+
+```js
+import { parseMIMEType } from 'undici'
+
+parseMIMEType('text/html; charset=gbk')
+// {
+//   type: 'text',
+//   subtype: 'html',
+//   parameters: Map(1) { 'charset' => 'gbk' },
+//   essence: 'text/html'
+// }
+```
+
+Arguments:
+
+* **input** `string`
+
+Returns: `MIMEType|'failure'`
+
+## `serializeAMimeType(input)`
+
+Implements [serialize a MIME type](https://mimesniff.spec.whatwg.org/#serialize-a-mime-type).
+
+Serializes a MIMEType object.
+
+```js
+import { serializeAMimeType } from 'undici'
+
+serializeAMimeType({
+  type: 'text',
+  subtype: 'html',
+  parameters: new Map([['charset', 'gbk']]),
+  essence: 'text/html'
+})
+// text/html;charset=gbk
+
+```
+
+Arguments:
+
+* **mimeType** `MIMEType`
+
+Returns: `string`
diff --git a/docs/api/Cookies.md b/docs/api/Cookies.md
new file mode 100644
index 0000000..0cad379
--- /dev/null
+++ b/docs/api/Cookies.md
@@ -0,0 +1,101 @@
+# Cookie Handling
+
+## `Cookie` interface
+
+* **name** `string`
+* **value** `string`
+* **expires** `Date|number` (optional)
+* **maxAge** `number` (optional)
+* **domain** `string` (optional)
+* **path** `string` (optional)
+* **secure** `boolean` (optional)
+* **httpOnly** `boolean` (optional)
+* **sameSite** `'String'|'Lax'|'None'` (optional)
+* **unparsed** `string[]` (optional) Left over attributes that weren't parsed.
+
+## `deleteCookie(headers, name[, attributes])`
+
+Sets the expiry time of the cookie to the unix epoch, causing browsers to delete it when received.
+
+```js
+import { deleteCookie, Headers } from 'undici'
+
+const headers = new Headers()
+deleteCookie(headers, 'name')
+
+console.log(headers.get('set-cookie')) // name=; Expires=Thu, 01 Jan 1970 00:00:00 GMT
+```
+
+Arguments:
+
+* **headers** `Headers`
+* **name** `string`
+* **attributes** `{ path?: string, domain?: string }` (optional)
+
+Returns: `void`
+
+## `getCookies(headers)`
+
+Parses the `Cookie` header and returns a list of attributes and values.
+
+```js
+import { getCookies, Headers } from 'undici'
+
+const headers = new Headers({
+  cookie: 'get=cookies; and=attributes'
+})
+
+console.log(getCookies(headers)) // { get: 'cookies', and: 'attributes' }
+```
+
+Arguments:
+
+* **headers** `Headers`
+
+Returns: `Record<string, string>`
+
+## `getSetCookies(headers)`
+
+Parses all `Set-Cookie` headers.
+
+```js
+import { getSetCookies, Headers } from 'undici'
+
+const headers = new Headers({ 'set-cookie': 'undici=getSetCookies; Secure' })
+
+console.log(getSetCookies(headers))
+// [
+//   {
+//     name: 'undici',
+//     value: 'getSetCookies',
+//     secure: true
+//   }
+// ]
+
+```
+
+Arguments:
+
+* **headers** `Headers`
+
+Returns: `Cookie[]`
+
+## `setCookie(headers, cookie)`
+
+Appends a cookie to the `Set-Cookie` header.
+
+```js
+import { setCookie, Headers } from 'undici'
+
+const headers = new Headers()
+setCookie(headers, { name: 'undici', value: 'setCookie' })
+
+console.log(headers.get('Set-Cookie')) // undici=setCookie
+```
+
+Arguments:
+
+* **headers** `Headers`
+* **cookie** `Cookie`
+
+Returns: `void`
diff --git a/docs/api/DiagnosticsChannel.md b/docs/api/DiagnosticsChannel.md
new file mode 100644
index 0000000..0aa0b9a
--- /dev/null
+++ b/docs/api/DiagnosticsChannel.md
@@ -0,0 +1,204 @@
+# Diagnostics Channel Support
+
+Stability: Experimental.
+
+Undici supports the [`diagnostics_channel`](https://nodejs.org/api/diagnostics_channel.html) (currently available only on Node.js v16+).
+It is the preferred way to instrument Undici and retrieve internal information.
+
+The channels available are the following.
+
+## `undici:request:create`
+
+This message is published when a new outgoing request is created.
+
+```js
+import diagnosticsChannel from 'diagnostics_channel'
+
+diagnosticsChannel.channel('undici:request:create').subscribe(({ request }) => {
+  console.log('origin', request.origin)
+  console.log('completed', request.completed)
+  console.log('method', request.method)
+  console.log('path', request.path)
+  console.log('headers') // raw text, e.g: 'bar: bar\r\n'
+  request.addHeader('hello', 'world')
+  console.log('headers', request.headers) // e.g. 'bar: bar\r\nhello: world\r\n'
+})
+```
+
+Note: a request is only loosely completed to a given socket.
+
+
+## `undici:request:bodySent`
+
+```js
+import diagnosticsChannel from 'diagnostics_channel'
+
+diagnosticsChannel.channel('undici:request:bodySent').subscribe(({ request }) => {
+  // request is the same object undici:request:create
+})
+```
+
+## `undici:request:headers`
+
+This message is published after the response headers have been received, i.e. the response has been completed.
+
+```js
+import diagnosticsChannel from 'diagnostics_channel'
+
+diagnosticsChannel.channel('undici:request:headers').subscribe(({ request, response }) => {
+  // request is the same object undici:request:create
+  console.log('statusCode', response.statusCode)
+  console.log(response.statusText)
+  // response.headers are buffers.
+  console.log(response.headers.map((x) => x.toString()))
+})
+```
+
+## `undici:request:trailers`
+
+This message is published after the response body and trailers have been received, i.e. the response has been completed.
+
+```js
+import diagnosticsChannel from 'diagnostics_channel'
+
+diagnosticsChannel.channel('undici:request:trailers').subscribe(({ request, trailers }) => {
+  // request is the same object undici:request:create
+  console.log('completed', request.completed)
+  // trailers are buffers.
+  console.log(trailers.map((x) => x.toString()))
+})
+```
+
+## `undici:request:error`
+
+This message is published if the request is going to error, but it has not errored yet.
+
+```js
+import diagnosticsChannel from 'diagnostics_channel'
+
+diagnosticsChannel.channel('undici:request:error').subscribe(({ request, error }) => {
+  // request is the same object undici:request:create
+})
+```
+
+## `undici:client:sendHeaders`
+
+This message is published right before the first byte of the request is written to the socket.
+
+*Note*: It will publish the exact headers that will be sent to the server in raw format.
+
+```js
+import diagnosticsChannel from 'diagnostics_channel'
+
+diagnosticsChannel.channel('undici:client:sendHeaders').subscribe(({ request, headers, socket }) => {
+  // request is the same object undici:request:create
+  console.log(`Full headers list ${headers.split('\r\n')}`);
+})
+```
+
+## `undici:client:beforeConnect`
+
+This message is published before creating a new connection for **any** request.
+You can not assume that this event is related to any specific request.
+
+```js
+import diagnosticsChannel from 'diagnostics_channel'
+
+diagnosticsChannel.channel('undici:client:beforeConnect').subscribe(({ connectParams, connector }) => {
+  // const { host, hostname, protocol, port, servername } = connectParams
+  // connector is a function that creates the socket
+})
+```
+
+## `undici:client:connected`
+
+This message is published after a connection is established.
+
+```js
+import diagnosticsChannel from 'diagnostics_channel'
+
+diagnosticsChannel.channel('undici:client:connected').subscribe(({ socket, connectParams, connector }) => {
+  // const { host, hostname, protocol, port, servername } = connectParams
+ // connector is a function that creates the socket
+})
+```
+
+## `undici:client:connectError`
+
+This message is published if it did not succeed to create new connection
+
+```js
+import diagnosticsChannel from 'diagnostics_channel'
+
+diagnosticsChannel.channel('undici:client:connectError').subscribe(({ error, socket, connectParams, connector }) => {
+  // const { host, hostname, protocol, port, servername } = connectParams
+  // connector is a function that creates the socket
+  console.log(`Connect failed with ${error.message}`)
+})
+```
+
+## `undici:websocket:open`
+
+This message is published after the client has successfully connected to a server.
+
+```js
+import diagnosticsChannel from 'diagnostics_channel'
+
+diagnosticsChannel.channel('undici:websocket:open').subscribe(({ address, protocol, extensions }) => {
+  console.log(address) // address, family, and port
+  console.log(protocol) // negotiated subprotocols
+  console.log(extensions) // negotiated extensions
+})
+```
+
+## `undici:websocket:close`
+
+This message is published after the connection has closed.
+
+```js
+import diagnosticsChannel from 'diagnostics_channel'
+
+diagnosticsChannel.channel('undici:websocket:close').subscribe(({ websocket, code, reason }) => {
+  console.log(websocket) // the WebSocket object
+  console.log(code) // the closing status code
+  console.log(reason) // the closing reason
+})
+```
+
+## `undici:websocket:socket_error`
+
+This message is published if the socket experiences an error.
+
+```js
+import diagnosticsChannel from 'diagnostics_channel'
+
+diagnosticsChannel.channel('undici:websocket:socket_error').subscribe((error) => {
+  console.log(error)
+})
+```
+
+## `undici:websocket:ping`
+
+This message is published after the client receives a ping frame, if the connection is not closing.
+
+```js
+import diagnosticsChannel from 'diagnostics_channel'
+
+diagnosticsChannel.channel('undici:websocket:ping').subscribe(({ payload }) => {
+  // a Buffer or undefined, containing the optional application data of the frame
+  console.log(payload)
+})
+```
+
+## `undici:websocket:pong`
+
+This message is published after the client receives a pong frame.
+
+```js
+import diagnosticsChannel from 'diagnostics_channel'
+
+diagnosticsChannel.channel('undici:websocket:pong').subscribe(({ payload }) => {
+  // a Buffer or undefined, containing the optional application data of the frame
+  console.log(payload)
+})
+```
diff --git a/docs/api/DispatchInterceptor.md b/docs/api/DispatchInterceptor.md
new file mode 100644
index 0000000..7dfc260
--- /dev/null
+++ b/docs/api/DispatchInterceptor.md
@@ -0,0 +1,60 @@
+# Interface: DispatchInterceptor
+
+Extends: `Function`
+
+A function that can be applied to the `Dispatcher.Dispatch` function before it is invoked with a dispatch request.
+
+This allows one to write logic to intercept both the outgoing request, and the incoming response.
+
+### Parameter: `Dispatcher.Dispatch`
+
+The base dispatch function you are decorating.
+
+### ReturnType: `Dispatcher.Dispatch`
+
+A dispatch function that has been altered to provide additional logic
+
+### Basic Example
+
+Here is an example of an interceptor being used to provide a JWT bearer token
+
+```js
+'use strict'
+
+const insertHeaderInterceptor = dispatch => {
+  return function InterceptedDispatch(opts, handler){
+    opts.headers.push('Authorization', 'Bearer [Some token]')
+    return dispatch(opts, handler)
+  }
+}
+
+const client = new Client('https://localhost:3000', {
+  interceptors: { Client: [insertHeaderInterceptor] }
+})
+
+```
+
+### Basic Example 2
+
+Here is a contrived example of an interceptor stripping the headers from a response.
+
+```js
+'use strict'
+
+const clearHeadersInterceptor = dispatch => {
+  const { DecoratorHandler } = require('undici')
+  class ResultInterceptor extends DecoratorHandler {
+    onHeaders (statusCode, headers, resume) {
+      return super.onHeaders(statusCode, [], resume)
+    }
+  }
+  return function InterceptedDispatch(opts, handler){
+    return dispatch(opts, new ResultInterceptor(handler))
+  }
+}
+
+const client = new Client('https://localhost:3000', {
+  interceptors: { Client: [clearHeadersInterceptor] }
+})
+
+```
diff --git a/docs/api/Dispatcher.md b/docs/api/Dispatcher.md
new file mode 100644
index 0000000..fd463bf
--- /dev/null
+++ b/docs/api/Dispatcher.md
@@ -0,0 +1,887 @@
+# Dispatcher
+
+Extends: `events.EventEmitter`
+
+Dispatcher is the core API used to dispatch requests.
+
+Requests are not guaranteed to be dispatched in order of invocation.
+
+## Instance Methods
+
+### `Dispatcher.close([callback]): Promise`
+
+Closes the dispatcher and gracefully waits for enqueued requests to complete before resolving.
+
+Arguments:
+
+* **callback** `(error: Error | null, data: null) => void` (optional)
+
+Returns: `void | Promise<null>` - Only returns a `Promise` if no `callback` argument was passed
+
+```js
+dispatcher.close() // -> Promise
+dispatcher.close(() => {}) // -> void
+```
+
+#### Example - Request resolves before Client closes
+
+```js
+import { createServer } from 'http'
+import { Client } from 'undici'
+import { once } from 'events'
+
+const server = createServer((request, response) => {
+  response.end('undici')
+}).listen()
+
+await once(server, 'listening')
+
+const client = new Client(`http://localhost:${server.address().port}`)
+
+try {
+  const { body } = await client.request({
+      path: '/',
+      method: 'GET'
+  })
+  body.setEncoding('utf8')
+  body.on('data', console.log)
+} catch (error) {}
+
+await client.close()
+
+console.log('Client closed')
+server.close()
+```
+
+### `Dispatcher.connect(options[, callback])`
+
+Starts two-way communications with the requested resource using [HTTP CONNECT](https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/CONNECT).
+
+Arguments:
+
+* **options** `ConnectOptions`
+* **callback** `(err: Error | null, data: ConnectData | null) => void` (optional)
+
+Returns: `void | Promise<ConnectData>` - Only returns a `Promise` if no `callback` argument was passed
+
+#### Parameter: `ConnectOptions`
+
+* **path** `string`
+* **headers** `UndiciHeaders` (optional) - Default: `null`
+* **signal** `AbortSignal | events.EventEmitter | null` (optional) - Default: `null`
+* **opaque** `unknown` (optional) - This argument parameter is passed through to `ConnectData`
+
+#### Parameter: `ConnectData`
+
+* **statusCode** `number`
+* **headers** `Record<string, string | string[] | undefined>`
+* **socket** `stream.Duplex`
+* **opaque** `unknown`
+
+#### Example - Connect request with echo
+
+```js
+import { createServer } from 'http'
+import { Client } from 'undici'
+import { once } from 'events'
+
+const server = createServer((request, response) => {
+  throw Error('should never get here')
+}).listen()
+
+server.on('connect', (req, socket, head) => {
+  socket.write('HTTP/1.1 200 Connection established\r\n\r\n')
+
+  let data = head.toString()
+  socket.on('data', (buf) => {
+    data += buf.toString()
+  })
+
+  socket.on('end', () => {
+    socket.end(data)
+  })
+})
+
+await once(server, 'listening')
+
+const client = new Client(`http://localhost:${server.address().port}`)
+
+try {
+  const { socket } = await client.connect({
+    path: '/'
+  })
+  const wanted = 'Body'
+  let data = ''
+  socket.on('data', d => { data += d })
+  socket.on('end', () => {
+    console.log(`Data received: ${data.toString()} | Data wanted: ${wanted}`)
+    client.close()
+    server.close()
+  })
+  socket.write(wanted)
+  socket.end()
+} catch (error) { }
+```
+
+### `Dispatcher.destroy([error, callback]): Promise`
+
+Destroy the dispatcher abruptly with the given error. All the pending and running requests will be asynchronously aborted and error. Since this operation is asynchronously dispatched there might still be some progress on dispatched requests.
+
+Both arguments are optional; the method can be called in four different ways:
+
+Arguments:
+
+* **error** `Error | null` (optional)
+* **callback** `(error: Error | null, data: null) => void` (optional)
+
+Returns: `void | Promise<void>` - Only returns a `Promise` if no `callback` argument was passed
+
+```js
+dispatcher.destroy() // -> Promise
+dispatcher.destroy(new Error()) // -> Promise
+dispatcher.destroy(() => {}) // -> void
+dispatcher.destroy(new Error(), () => {}) // -> void
+```
+
+#### Example - Request is aborted when Client is destroyed
+
+```js
+import { createServer } from 'http'
+import { Client } from 'undici'
+import { once } from 'events'
+
+const server = createServer((request, response) => {
+  response.end()
+}).listen()
+
+await once(server, 'listening')
+
+const client = new Client(`http://localhost:${server.address().port}`)
+
+try {
+  const request = client.request({
+    path: '/',
+    method: 'GET'
+  })
+  client.destroy()
+    .then(() => {
+      console.log('Client destroyed')
+      server.close()
+    })
+  await request
+} catch (error) {
+  console.error(error)
+}
+```
+
+### `Dispatcher.dispatch(options, handler)`
+
+This is the low level API which all the preceding APIs are implemented on top of.
+This API is expected to evolve through semver-major versions and is less stable than the preceding higher level APIs.
+It is primarily intended for library developers who implement higher level APIs on top of this.
+
+Arguments:
+
+* **options** `DispatchOptions`
+* **handler** `DispatchHandler`
+
+Returns: `Boolean` - `false` if dispatcher is busy and further dispatch calls won't make any progress until the `'drain'` event has been emitted.
+
+#### Parameter: `DispatchOptions`
+
+* **origin** `string | URL`
+* **path** `string`
+* **method** `string`
+* **reset** `boolean` (optional) - Default: `false` - If `false`, the request will attempt to create a long-living connection by sending the `connection: keep-alive` header,otherwise will attempt to close it immediately after response by sending `connection: close` within the request and closing the socket afterwards.
+* **body** `string | Buffer | Uint8Array | stream.Readable | Iterable | AsyncIterable | null` (optional) - Default: `null`
+* **headers** `UndiciHeaders | string[]` (optional) - Default: `null`.
+* **query** `Record<string, any> | null` (optional) - Default: `null` - Query string params to be embedded in the request URL. Note that both keys and values of query are encoded using `encodeURIComponent`. If for some reason you need to send them unencoded, embed query params into path directly instead.
+* **idempotent** `boolean` (optional) - Default: `true` if `method` is `'HEAD'` or `'GET'` - Whether the requests can be safely retried or not. If `false` the request won't be sent until all preceding requests in the pipeline has completed.
+* **blocking** `boolean` (optional) - Default: `false` - Whether the response is expected to take a long time and would end up blocking the pipeline. When this is set to `true` further pipelining will be avoided on the same connection until headers have been received.
+* **upgrade** `string | null` (optional) - Default: `null` - Upgrade the request. Should be used to specify the kind of upgrade i.e. `'Websocket'`.
+* **bodyTimeout** `number | null` (optional) - The timeout after which a request will time out, in milliseconds. Monitors time between receiving body data. Use `0` to disable it entirely. Defaults to 300 seconds.
+* **headersTimeout** `number | null` (optional) - The amount of time, in milliseconds, the parser will wait to receive the complete HTTP headers while not sending the request. Defaults to 300 seconds.
+* **throwOnError** `boolean` (optional) - Default: `false` - Whether Undici should throw an error upon receiving a 4xx or 5xx response from the server.
+* **expectContinue** `boolean` (optional) - Default: `false` - For H2, it appends the expect: 100-continue header, and halts the request body until a 100-continue is received from the remote server
+
+#### Parameter: `DispatchHandler`
+
+* **onConnect** `(abort: () => void, context: object) => void` - Invoked before request is dispatched on socket. May be invoked multiple times when a request is retried when the request at the head of the pipeline fails.
+* **onError** `(error: Error) => void` - Invoked when an error has occurred. May not throw.
+* **onUpgrade** `(statusCode: number, headers: Buffer[], socket: Duplex) => void` (optional) - Invoked when request is upgraded. Required if `DispatchOptions.upgrade` is defined or `DispatchOptions.method === 'CONNECT'`.
+* **onHeaders** `(statusCode: number, headers: Buffer[], resume: () => void, statusText: string) => boolean` - Invoked when statusCode and headers have been received. May be invoked multiple times due to 1xx informational headers. Not required for `upgrade` requests.
+* **onData** `(chunk: Buffer) => boolean` - Invoked when response payload data is received. Not required for `upgrade` requests.
+* **onComplete** `(trailers: Buffer[]) => void` - Invoked when response payload and trailers have been received and the request has completed. Not required for `upgrade` requests.
+* **onBodySent** `(chunk: string | Buffer | Uint8Array) => void` - Invoked when a body chunk is sent to the server. Not required. For a stream or iterable body this will be invoked for every chunk. For other body types, it will be invoked once after the body is sent.
+
+#### Example 1 - Dispatch GET request
+
+```js
+import { createServer } from 'http'
+import { Client } from 'undici'
+import { once } from 'events'
+
+const server = createServer((request, response) => {
+  response.end('Hello, World!')
+}).listen()
+
+await once(server, 'listening')
+
+const client = new Client(`http://localhost:${server.address().port}`)
+
+const data = []
+
+client.dispatch({
+  path: '/',
+  method: 'GET',
+  headers: {
+    'x-foo': 'bar'
+  }
+}, {
+  onConnect: () => {
+    console.log('Connected!')
+  },
+  onError: (error) => {
+    console.error(error)
+  },
+  onHeaders: (statusCode, headers) => {
+    console.log(`onHeaders | statusCode: ${statusCode} | headers: ${headers}`)
+  },
+  onData: (chunk) => {
+    console.log('onData: chunk received')
+    data.push(chunk)
+  },
+  onComplete: (trailers) => {
+    console.log(`onComplete | trailers: ${trailers}`)
+    const res = Buffer.concat(data).toString('utf8')
+    console.log(`Data: ${res}`)
+    client.close()
+    server.close()
+  }
+})
+```
+
+#### Example 2 - Dispatch Upgrade Request
+
+```js
+import { createServer } from 'http'
+import { Client } from 'undici'
+import { once } from 'events'
+
+const server = createServer((request, response) => {
+  response.end()
+}).listen()
+
+await once(server, 'listening')
+
+server.on('upgrade', (request, socket, head) => {
+  console.log('Node.js Server - upgrade event')
+  socket.write('HTTP/1.1 101 Web Socket Protocol Handshake\r\n')
+  socket.write('Upgrade: WebSocket\r\n')
+  socket.write('Connection: Upgrade\r\n')
+  socket.write('\r\n')
+  socket.end()
+})
+
+const client = new Client(`http://localhost:${server.address().port}`)
+
+client.dispatch({
+  path: '/',
+  method: 'GET',
+  upgrade: 'websocket'
+}, {
+  onConnect: () => {
+    console.log('Undici Client - onConnect')
+  },
+  onError: (error) => {
+    console.log('onError') // shouldn't print
+  },
+  onUpgrade: (statusCode, headers, socket) => {
+    console.log('Undici Client - onUpgrade')
+    console.log(`onUpgrade Headers: ${headers}`)
+    socket.on('data', buffer => {
+      console.log(buffer.toString('utf8'))
+    })
+    socket.on('end', () => {
+      client.close()
+      server.close()
+    })
+    socket.end()
+  }
+})
+```
+
+#### Example 3 - Dispatch POST request
+
+```js
+import { createServer } from 'http'
+import { Client } from 'undici'
+import { once } from 'events'
+
+const server = createServer((request, response) => {
+  request.on('data', (data) => {
+    console.log(`Request Data: ${data.toString('utf8')}`)
+    const body = JSON.parse(data)
+    body.message = 'World'
+    response.end(JSON.stringify(body))
+  })
+}).listen()
+
+await once(server, 'listening')
+
+const client = new Client(`http://localhost:${server.address().port}`)
+
+const data = []
+
+client.dispatch({
+  path: '/',
+  method: 'POST',
+  headers: {
+    'content-type': 'application/json'
+  },
+  body: JSON.stringify({ message: 'Hello' })
+}, {
+  onConnect: () => {
+    console.log('Connected!')
+  },
+  onError: (error) => {
+    console.error(error)
+  },
+  onHeaders: (statusCode, headers) => {
+    console.log(`onHeaders | statusCode: ${statusCode} | headers: ${headers}`)
+  },
+  onData: (chunk) => {
+    console.log('onData: chunk received')
+    data.push(chunk)
+  },
+  onComplete: (trailers) => {
+    console.log(`onComplete | trailers: ${trailers}`)
+    const res = Buffer.concat(data).toString('utf8')
+    console.log(`Response Data: ${res}`)
+    client.close()
+    server.close()
+  }
+})
+```
+
+### `Dispatcher.pipeline(options, handler)`
+
+For easy use with [stream.pipeline](https://nodejs.org/api/stream.html#stream_stream_pipeline_source_transforms_destination_callback). The `handler` argument should return a `Readable` from which the result will be read. Usually it should just return the `body` argument unless some kind of transformation needs to be performed based on e.g. `headers` or `statusCode`. The `handler` should validate the response and save any required state. If there is an error, it should be thrown. The function returns a `Duplex` which writes to the request and reads from the response.
+
+Arguments:
+
+* **options** `PipelineOptions`
+* **handler** `(data: PipelineHandlerData) => stream.Readable`
+
+Returns: `stream.Duplex`
+
+#### Parameter: PipelineOptions
+
+Extends: [`RequestOptions`](#parameter-requestoptions)
+
+* **objectMode** `boolean` (optional) - Default: `false` - Set to `true` if the `handler` will return an object stream.
+
+#### Parameter: PipelineHandlerData
+
+* **statusCode** `number`
+* **headers** `Record<string, string | string[] | undefined>`
+* **opaque** `unknown`
+* **body** `stream.Readable`
+* **context** `object`
+* **onInfo** `({statusCode: number, headers: Record<string, string | string[]>}) => void | null` (optional) - Default: `null` - Callback collecting all the info headers (HTTP 100-199) received.
+
+#### Example 1 - Pipeline Echo
+
+```js
+import { Readable, Writable, PassThrough, pipeline } from 'stream'
+import { createServer } from 'http'
+import { Client } from 'undici'
+import { once } from 'events'
+
+const server = createServer((request, response) => {
+  request.pipe(response)
+}).listen()
+
+await once(server, 'listening')
+
+const client = new Client(`http://localhost:${server.address().port}`)
+
+let res = ''
+
+pipeline(
+  new Readable({
+    read () {
+      this.push(Buffer.from('undici'))
+      this.push(null)
+    }
+  }),
+  client.pipeline({
+    path: '/',
+    method: 'GET'
+  }, ({ statusCode, headers, body }) => {
+    console.log(`response received ${statusCode}`)
+    console.log('headers', headers)
+    return pipeline(body, new PassThrough(), () => {})
+  }),
+  new Writable({
+    write (chunk, _, callback) {
+      res += chunk.toString()
+      callback()
+    },
+    final (callback) {
+      console.log(`Response pipelined to writable: ${res}`)
+      callback()
+    }
+  }),
+  error => {
+    if (error) {
+      console.error(error)
+    }
+
+    client.close()
+    server.close()
+  }
+)
+```
+
+### `Dispatcher.request(options[, callback])`
+
+Performs a HTTP request.
+
+Non-idempotent requests will not be pipelined in order
+to avoid indirect failures.
+
+Idempotent requests will be automatically retried if
+they fail due to indirect failure from the request
+at the head of the pipeline. This does not apply to
+idempotent requests with a stream request body.
+
+All response bodies must always be fully consumed or destroyed.
+
+Arguments:
+
+* **options** `RequestOptions`
+* **callback** `(error: Error | null, data: ResponseData) => void` (optional)
+
+Returns: `void | Promise<ResponseData>` - Only returns a `Promise` if no `callback` argument was passed.
+
+#### Parameter: `RequestOptions`
+
+Extends: [`DispatchOptions`](#parameter-dispatchoptions)
+
+* **opaque** `unknown` (optional) - Default: `null` - Used for passing through context to `ResponseData`.
+* **signal** `AbortSignal | events.EventEmitter | null` (optional) - Default: `null`.
+* **onInfo** `({statusCode: number, headers: Record<string, string | string[]>}) => void | null` (optional) - Default: `null` - Callback collecting all the info headers (HTTP 100-199) received.
+
+The `RequestOptions.method` property should not be value `'CONNECT'`.
+
+#### Parameter: `ResponseData`
+
+* **statusCode** `number`
+* **headers** `Record<string, string | string[]>` - Note that all header keys are lower-cased, e. g. `content-type`.
+* **body** `stream.Readable` which also implements [the body mixin from the Fetch Standard](https://fetch.spec.whatwg.org/#body-mixin).
+* **trailers** `Record<string, string>` - This object starts out
+  as empty and will be mutated to contain trailers after `body` has emitted `'end'`.
+* **opaque** `unknown`
+* **context** `object`
+
+`body` contains the following additional [body mixin](https://fetch.spec.whatwg.org/#body-mixin) methods and properties:
+
+- `text()`
+- `json()`
+- `arrayBuffer()`
+- `body`
+- `bodyUsed`
+
+`body` can not be consumed twice. For example, calling `text()` after `json()` throws `TypeError`.
+
+`body` contains the following additional extensions:
+
+- `dump({ limit: Integer })`, dump the response by reading up to `limit` bytes without killing the socket (optional) - Default: 262144.
+
+Note that body will still be a `Readable` even if it is empty, but attempting to deserialize it with `json()` will result in an exception. Recommended way to ensure there is a body to deserialize is to check if status code is not 204, and `content-type` header starts with `application/json`.
+
+#### Example 1 - Basic GET Request
+
+```js
+import { createServer } from 'http'
+import { Client } from 'undici'
+import { once } from 'events'
+
+const server = createServer((request, response) => {
+  response.end('Hello, World!')
+}).listen()
+
+await once(server, 'listening')
+
+const client = new Client(`http://localhost:${server.address().port}`)
+
+try {
+  const { body, headers, statusCode, trailers } = await client.request({
+    path: '/',
+    method: 'GET'
+  })
+  console.log(`response received ${statusCode}`)
+  console.log('headers', headers)
+  body.setEncoding('utf8')
+  body.on('data', console.log)
+  body.on('end', () => {
+    console.log('trailers', trailers)
+  })
+
+  client.close()
+  server.close()
+} catch (error) {
+  console.error(error)
+}
+```
+
+#### Example 2 - Aborting a request
+
+> Node.js v15+ is required to run this example
+
+```js
+import { createServer } from 'http'
+import { Client } from 'undici'
+import { once } from 'events'
+
+const server = createServer((request, response) => {
+  response.end('Hello, World!')
+}).listen()
+
+await once(server, 'listening')
+
+const client = new Client(`http://localhost:${server.address().port}`)
+const abortController = new AbortController()
+
+try {
+  client.request({
+    path: '/',
+    method: 'GET',
+    signal: abortController.signal
+  })
+} catch (error) {
+  console.error(error) // should print an RequestAbortedError
+  client.close()
+  server.close()
+}
+
+abortController.abort()
+```
+
+Alternatively, any `EventEmitter` that emits an `'abort'` event may be used as an abort controller:
+
+```js
+import { createServer } from 'http'
+import { Client } from 'undici'
+import EventEmitter, { once } from 'events'
+
+const server = createServer((request, response) => {
+  response.end('Hello, World!')
+}).listen()
+
+await once(server, 'listening')
+
+const client = new Client(`http://localhost:${server.address().port}`)
+const ee = new EventEmitter()
+
+try {
+  client.request({
+    path: '/',
+    method: 'GET',
+    signal: ee
+  })
+} catch (error) {
+  console.error(error) // should print an RequestAbortedError
+  client.close()
+  server.close()
+}
+
+ee.emit('abort')
+```
+
+Destroying the request or response body will have the same effect.
+
+```js
+import { createServer } from 'http'
+import { Client } from 'undici'
+import { once } from 'events'
+
+const server = createServer((request, response) => {
+  response.end('Hello, World!')
+}).listen()
+
+await once(server, 'listening')
+
+const client = new Client(`http://localhost:${server.address().port}`)
+
+try {
+  const { body } = await client.request({
+    path: '/',
+    method: 'GET'
+  })
+  body.destroy()
+} catch (error) {
+  console.error(error) // should print an RequestAbortedError
+  client.close()
+  server.close()
+}
+```
+
+### `Dispatcher.stream(options, factory[, callback])`
+
+A faster version of `Dispatcher.request`. This method expects the second argument `factory` to return a [`stream.Writable`](https://nodejs.org/api/stream.html#stream_class_stream_writable) stream which the response will be written to. This improves performance by avoiding creating an intermediate [`stream.Readable`](https://nodejs.org/api/stream.html#stream_readable_streams) stream when the user expects to directly pipe the response body to a [`stream.Writable`](https://nodejs.org/api/stream.html#stream_class_stream_writable) stream.
+
+As demonstrated in [Example 1 - Basic GET stream request](#example-1---basic-get-stream-request), it is recommended to use the `option.opaque` property to avoid creating a closure for the `factory` method. This pattern works well with Node.js Web Frameworks such as [Fastify](https://fastify.io). See [Example 2 - Stream to Fastify Response](#example-2---stream-to-fastify-response) for more details.
+
+Arguments:
+
+* **options** `RequestOptions`
+* **factory** `(data: StreamFactoryData) => stream.Writable`
+* **callback** `(error: Error | null, data: StreamData) => void` (optional)
+
+Returns: `void | Promise<StreamData>` - Only returns a `Promise` if no `callback` argument was passed
+
+#### Parameter: `StreamFactoryData`
+
+* **statusCode** `number`
+* **headers** `Record<string, string | string[] | undefined>`
+* **opaque** `unknown`
+* **onInfo** `({statusCode: number, headers: Record<string, string | string[]>}) => void | null` (optional) - Default: `null` - Callback collecting all the info headers (HTTP 100-199) received.
+
+#### Parameter: `StreamData`
+
+* **opaque** `unknown`
+* **trailers** `Record<string, string>`
+* **context** `object`
+
+#### Example 1 - Basic GET stream request
+
+```js
+import { createServer } from 'http'
+import { Client } from 'undici'
+import { once } from 'events'
+import { Writable } from 'stream'
+
+const server = createServer((request, response) => {
+  response.end('Hello, World!')
+}).listen()
+
+await once(server, 'listening')
+
+const client = new Client(`http://localhost:${server.address().port}`)
+
+const bufs = []
+
+try {
+  await client.stream({
+    path: '/',
+    method: 'GET',
+    opaque: { bufs }
+  }, ({ statusCode, headers, opaque: { bufs } }) => {
+    console.log(`response received ${statusCode}`)
+    console.log('headers', headers)
+    return new Writable({
+      write (chunk, encoding, callback) {
+        bufs.push(chunk)
+        callback()
+      }
+    })
+  })
+
+  console.log(Buffer.concat(bufs).toString('utf-8'))
+
+  client.close()
+  server.close()
+} catch (error) {
+  console.error(error)
+}
+```
+
+#### Example 2 - Stream to Fastify Response
+
+In this example, a (fake) request is made to the fastify server using `fastify.inject()`. This request then executes the fastify route handler which makes a subsequent request to the raw Node.js http server using `undici.dispatcher.stream()`. The fastify response is passed to the `opaque` option so that undici can tap into the underlying writable stream using `response.raw`. This methodology demonstrates how one could use undici and fastify together to create fast-as-possible requests from one backend server to another.
+
+```js
+import { createServer } from 'http'
+import { Client } from 'undici'
+import { once } from 'events'
+import fastify from 'fastify'
+
+const nodeServer = createServer((request, response) => {
+  response.end('Hello, World! From Node.js HTTP Server')
+}).listen()
+
+await once(nodeServer, 'listening')
+
+console.log('Node Server listening')
+
+const nodeServerUndiciClient = new Client(`http://localhost:${nodeServer.address().port}`)
+
+const fastifyServer = fastify()
+
+fastifyServer.route({
+  url: '/',
+  method: 'GET',
+  handler: (request, response) => {
+    nodeServerUndiciClient.stream({
+      path: '/',
+      method: 'GET',
+      opaque: response
+    }, ({ opaque }) => opaque.raw)
+  }
+})
+
+await fastifyServer.listen()
+
+console.log('Fastify Server listening')
+
+const fastifyServerUndiciClient = new Client(`http://localhost:${fastifyServer.server.address().port}`)
+
+try {
+  const { statusCode, body } = await fastifyServerUndiciClient.request({
+    path: '/',
+    method: 'GET'
+  })
+
+  console.log(`response received ${statusCode}`)
+  body.setEncoding('utf8')
+  body.on('data', console.log)
+
+  nodeServerUndiciClient.close()
+  fastifyServerUndiciClient.close()
+  fastifyServer.close()
+  nodeServer.close()
+} catch (error) { }
+```
+
+### `Dispatcher.upgrade(options[, callback])`
+
+Upgrade to a different protocol. Visit [MDN - HTTP - Protocol upgrade mechanism](https://developer.mozilla.org/en-US/docs/Web/HTTP/Protocol_upgrade_mechanism) for more details.
+
+Arguments:
+
+* **options** `UpgradeOptions`
+
+* **callback** `(error: Error | null, data: UpgradeData) => void` (optional)
+
+Returns: `void | Promise<UpgradeData>` - Only returns a `Promise` if no `callback` argument was passed
+
+#### Parameter: `UpgradeOptions`
+
+* **path** `string`
+* **method** `string` (optional) - Default: `'GET'`
+* **headers** `UndiciHeaders` (optional) - Default: `null`
+* **protocol** `string` (optional) - Default: `'Websocket'` - A string of comma separated protocols, in descending preference order.
+* **signal** `AbortSignal | EventEmitter | null` (optional) - Default: `null`
+
+#### Parameter: `UpgradeData`
+
+* **headers** `http.IncomingHeaders`
+* **socket** `stream.Duplex`
+* **opaque** `unknown`
+
+#### Example 1 - Basic Upgrade Request
+
+```js
+import { createServer } from 'http'
+import { Client } from 'undici'
+import { once } from 'events'
+
+const server = createServer((request, response) => {
+  response.statusCode = 101
+  response.setHeader('connection', 'upgrade')
+  response.setHeader('upgrade', request.headers.upgrade)
+  response.end()
+}).listen()
+
+await once(server, 'listening')
+
+const client = new Client(`http://localhost:${server.address().port}`)
+
+try {
+  const { headers, socket } = await client.upgrade({
+    path: '/',
+  })
+  socket.on('end', () => {
+    console.log(`upgrade: ${headers.upgrade}`) // upgrade: Websocket
+    client.close()
+    server.close()
+  })
+  socket.end()
+} catch (error) {
+  console.error(error)
+  client.close()
+  server.close()
+}
+```
+
+## Instance Events
+
+### Event: `'connect'`
+
+Parameters:
+
+* **origin** `URL`
+* **targets** `Array<Dispatcher>`
+
+### Event: `'disconnect'`
+
+Parameters:
+
+* **origin** `URL`
+* **targets** `Array<Dispatcher>`
+* **error** `Error`
+
+### Event: `'connectionError'`
+
+Parameters:
+
+* **origin** `URL`
+* **targets** `Array<Dispatcher>`
+* **error** `Error`
+
+Emitted when dispatcher fails to connect to
+origin.
+
+### Event: `'drain'`
+
+Parameters:
+
+* **origin** `URL`
+
+Emitted when dispatcher is no longer busy.
+
+## Parameter: `UndiciHeaders`
+
+* `Record<string, string | string[] | undefined> | string[] | null`
+
+Header arguments such as `options.headers` in [`Client.dispatch`](Client.md#clientdispatchoptions-handlers) can be specified in two forms; either as an object specified by the `Record<string, string | string[] | undefined>` (`IncomingHttpHeaders`) type, or an array of strings. An array representation of a header list must have an even length or an `InvalidArgumentError` will be thrown.
+
+Keys are lowercase and values are not modified.
+
+Response headers will derive a `host` from the `url` of the [Client](Client.md#class-client) instance if no `host` header was previously specified.
+
+### Example 1 - Object
+
+```js
+{
+  'content-length': '123',
+  'content-type': 'text/plain',
+  connection: 'keep-alive',
+  host: 'mysite.com',
+  accept: '*/*'
+}
+```
+
+### Example 2 - Array
+
+```js
+[
+  'content-length', '123',
+  'content-type', 'text/plain',
+  'connection', 'keep-alive',
+  'host', 'mysite.com',
+  'accept', '*/*'
+]
+```
diff --git a/docs/api/Errors.md b/docs/api/Errors.md
new file mode 100644
index 0000000..917e45d
--- /dev/null
+++ b/docs/api/Errors.md
@@ -0,0 +1,47 @@
+# Errors
+
+Undici exposes a variety of error objects that you can use to enhance your error handling.
+You can find all the error objects inside the `errors` key.
+
+```js
+import { errors } from 'undici'
+```
+
+| Error                                | Error Codes                           | Description                                                               |
+| ------------------------------------ | ------------------------------------- | ------------------------------------------------------------------------- |
+| `UndiciError`                        | `UND_ERR`                             | all errors below are extended from `UndiciError`.                         |
+| `ConnectTimeoutError`                | `UND_ERR_CONNECT_TIMEOUT`             | socket is destroyed due to connect timeout.                               |
+| `HeadersTimeoutError`                | `UND_ERR_HEADERS_TIMEOUT`             | socket is destroyed due to headers timeout.                               |
+| `HeadersOverflowError`               | `UND_ERR_HEADERS_OVERFLOW`            | socket is destroyed due to headers' max size being exceeded.              |
+| `BodyTimeoutError`                   | `UND_ERR_BODY_TIMEOUT`                | socket is destroyed due to body timeout.                                  |
+| `ResponseStatusCodeError`            | `UND_ERR_RESPONSE_STATUS_CODE`        | an error is thrown when `throwOnError` is `true` for status codes >= 400. |
+| `InvalidArgumentError`               | `UND_ERR_INVALID_ARG`                 | passed an invalid argument.                                               |
+| `InvalidReturnValueError`            | `UND_ERR_INVALID_RETURN_VALUE`        | returned an invalid value.                                                |
+| `RequestAbortedError`                | `UND_ERR_ABORTED`                     | the request has been aborted by the user                                  |
+| `ClientDestroyedError`               | `UND_ERR_DESTROYED`                   | trying to use a destroyed client.                                         |
+| `ClientClosedError`                  | `UND_ERR_CLOSED`                      | trying to use a closed client.                                            |
+| `SocketError`                        | `UND_ERR_SOCKET`                      | there is an error with the socket.                                        |
+| `NotSupportedError`                  | `UND_ERR_NOT_SUPPORTED`               | encountered unsupported functionality.                                    |
+| `RequestContentLengthMismatchError`  | `UND_ERR_REQ_CONTENT_LENGTH_MISMATCH` | request body does not match content-length header                         |
+| `ResponseContentLengthMismatchError` | `UND_ERR_RES_CONTENT_LENGTH_MISMATCH` | response body does not match content-length header                        |
+| `InformationalError`                 | `UND_ERR_INFO`                        | expected error with reason                                                |
+| `ResponseExceededMaxSizeError`       | `UND_ERR_RES_EXCEEDED_MAX_SIZE`       | response body exceed the max size allowed                                 |
+
+### `SocketError`
+
+The `SocketError` has a `.socket` property which holds socket metadata:
+
+```ts
+interface SocketInfo {
+  localAddress?: string
+  localPort?: number
+  remoteAddress?: string
+  remotePort?: number
+  remoteFamily?: string
+  timeout?: number
+  bytesWritten?: number
+  bytesRead?: number
+}
+```
+
+Be aware that in some cases the `.socket` property can be `null`.
diff --git a/docs/api/Fetch.md b/docs/api/Fetch.md
new file mode 100644
index 0000000..b5a6242
--- /dev/null
+++ b/docs/api/Fetch.md
@@ -0,0 +1,27 @@
+# Fetch
+
+Undici exposes a fetch() method starts the process of fetching a resource from the network.
+
+Documentation and examples can be found on [MDN](https://developer.mozilla.org/en-US/docs/Web/API/fetch).
+
+## File
+
+This API is implemented as per the standard, you can find documentation on [MDN](https://developer.mozilla.org/en-US/docs/Web/API/File)
+
+In Node versions v18.13.0 and above and v19.2.0 and above, undici will default to using Node's [File](https://nodejs.org/api/buffer.html#class-file) class. In versions where it's not available, it will default to the undici one.
+
+## FormData
+
+This API is implemented as per the standard, you can find documentation on [MDN](https://developer.mozilla.org/en-US/docs/Web/API/FormData)
+
+## Response
+
+This API is implemented as per the standard, you can find documentation on [MDN](https://developer.mozilla.org/en-US/docs/Web/API/Response)
+
+## Request
+
+This API is implemented as per the standard, you can find documentation on [MDN](https://developer.mozilla.org/en-US/docs/Web/API/Request)
+
+## Header
+
+This API is implemented as per the standard, you can find documentation on [MDN](https://developer.mozilla.org/en-US/docs/Web/API/Headers)
diff --git a/docs/api/MockAgent.md b/docs/api/MockAgent.md
new file mode 100644
index 0000000..85ae690
--- /dev/null
+++ b/docs/api/MockAgent.md
@@ -0,0 +1,540 @@
+# Class: MockAgent
+
+Extends: `undici.Dispatcher`
+
+A mocked Agent class that implements the Agent API. It allows one to intercept HTTP requests made through undici and return mocked responses instead.
+
+## `new MockAgent([options])`
+
+Arguments:
+
+* **options** `MockAgentOptions` (optional) - It extends the `Agent` options.
+
+Returns: `MockAgent`
+
+### Parameter: `MockAgentOptions`
+
+Extends: [`AgentOptions`](Agent.md#parameter-agentoptions)
+
+* **agent** `Agent` (optional) - Default: `new Agent([options])` - a custom agent encapsulated by the MockAgent.
+
+### Example - Basic MockAgent instantiation
+
+This will instantiate the MockAgent. It will not do anything until registered as the agent to use with requests and mock interceptions are added.
+
+```js
+import { MockAgent } from 'undici'
+
+const mockAgent = new MockAgent()
+```
+
+### Example - Basic MockAgent instantiation with custom agent
+
+```js
+import { Agent, MockAgent } from 'undici'
+
+const agent = new Agent()
+
+const mockAgent = new MockAgent({ agent })
+```
+
+## Instance Methods
+
+### `MockAgent.get(origin)`
+
+This method creates and retrieves MockPool or MockClient instances which can then be used to intercept HTTP requests. If the number of connections on the mock agent is set to 1, a MockClient instance is returned. Otherwise a MockPool instance is returned.
+
+For subsequent `MockAgent.get` calls on the same origin, the same mock instance will be returned.
+
+Arguments:
+
+* **origin** `string | RegExp | (value) => boolean` - a matcher for the pool origin to be retrieved from the MockAgent.
+
+| Matcher type | Condition to pass          |
+|:------------:| -------------------------- |
+| `string`     | Exact match against string |
+| `RegExp`     | Regex must pass            |
+| `Function`   | Function must return true  |
+
+Returns: `MockClient | MockPool`.
+
+| `MockAgentOptions`   | Mock instance returned |
+| -------------------- | ---------------------- |
+| `connections === 1`  | `MockClient`           |
+| `connections` > `1`  | `MockPool`             |
+
+#### Example - Basic Mocked Request
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+const mockPool = mockAgent.get('http://localhost:3000')
+mockPool.intercept({ path: '/foo' }).reply(200, 'foo')
+
+const { statusCode, body } = await request('http://localhost:3000/foo')
+
+console.log('response received', statusCode) // response received 200
+
+for await (const data of body) {
+  console.log('data', data.toString('utf8')) // data foo
+}
+```
+
+#### Example - Basic Mocked Request with local mock agent dispatcher
+
+```js
+import { MockAgent, request } from 'undici'
+
+const mockAgent = new MockAgent()
+
+const mockPool = mockAgent.get('http://localhost:3000')
+mockPool.intercept({ path: '/foo' }).reply(200, 'foo')
+
+const {
+  statusCode,
+  body
+} = await request('http://localhost:3000/foo', { dispatcher: mockAgent })
+
+console.log('response received', statusCode) // response received 200
+
+for await (const data of body) {
+  console.log('data', data.toString('utf8')) // data foo
+}
+```
+
+#### Example - Basic Mocked Request with local mock pool dispatcher
+
+```js
+import { MockAgent, request } from 'undici'
+
+const mockAgent = new MockAgent()
+
+const mockPool = mockAgent.get('http://localhost:3000')
+mockPool.intercept({ path: '/foo' }).reply(200, 'foo')
+
+const {
+  statusCode,
+  body
+} = await request('http://localhost:3000/foo', { dispatcher: mockPool })
+
+console.log('response received', statusCode) // response received 200
+
+for await (const data of body) {
+  console.log('data', data.toString('utf8')) // data foo
+}
+```
+
+#### Example - Basic Mocked Request with local mock client dispatcher
+
+```js
+import { MockAgent, request } from 'undici'
+
+const mockAgent = new MockAgent({ connections: 1 })
+
+const mockClient = mockAgent.get('http://localhost:3000')
+mockClient.intercept({ path: '/foo' }).reply(200, 'foo')
+
+const {
+  statusCode,
+  body
+} = await request('http://localhost:3000/foo', { dispatcher: mockClient })
+
+console.log('response received', statusCode) // response received 200
+
+for await (const data of body) {
+  console.log('data', data.toString('utf8')) // data foo
+}
+```
+
+#### Example - Basic Mocked requests with multiple intercepts
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+const mockPool = mockAgent.get('http://localhost:3000')
+mockPool.intercept({ path: '/foo' }).reply(200, 'foo')
+mockPool.intercept({ path: '/hello'}).reply(200, 'hello')
+
+const result1 = await request('http://localhost:3000/foo')
+
+console.log('response received', result1.statusCode) // response received 200
+
+for await (const data of result1.body) {
+  console.log('data', data.toString('utf8')) // data foo
+}
+
+const result2 = await request('http://localhost:3000/hello')
+
+console.log('response received', result2.statusCode) // response received 200
+
+for await (const data of result2.body) {
+  console.log('data', data.toString('utf8')) // data hello
+}
+```
+#### Example - Mock different requests within the same file
+```js
+const { MockAgent, setGlobalDispatcher } = require('undici');
+const agent = new MockAgent();
+agent.disableNetConnect();
+setGlobalDispatcher(agent);
+describe('Test', () => {
+  it('200', async () => {
+    const mockAgent = agent.get('http://test.com');
+    // your test
+  });
+  it('200', async () => {
+    const mockAgent = agent.get('http://testing.com');
+    // your test
+  });
+});
+```
+
+#### Example - Mocked request with query body, headers and trailers
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+const mockPool = mockAgent.get('http://localhost:3000')
+
+mockPool.intercept({
+  path: '/foo?hello=there&see=ya',
+  method: 'POST',
+  body: 'form1=data1&form2=data2'
+}).reply(200, { foo: 'bar' }, {
+  headers: { 'content-type': 'application/json' },
+  trailers: { 'Content-MD5': 'test' }
+})
+
+const {
+  statusCode,
+  headers,
+  trailers,
+  body
+} = await request('http://localhost:3000/foo?hello=there&see=ya', {
+  method: 'POST',
+  body: 'form1=data1&form2=data2'
+})
+
+console.log('response received', statusCode) // response received 200
+console.log('headers', headers) // { 'content-type': 'application/json' }
+
+for await (const data of body) {
+  console.log('data', data.toString('utf8')) // '{"foo":"bar"}'
+}
+
+console.log('trailers', trailers) // { 'content-md5': 'test' }
+```
+
+#### Example - Mocked request with origin regex
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+const mockPool = mockAgent.get(new RegExp('http://localhost:3000'))
+mockPool.intercept({ path: '/foo' }).reply(200, 'foo')
+
+const {
+  statusCode,
+  body
+} = await request('http://localhost:3000/foo')
+
+console.log('response received', statusCode) // response received 200
+
+for await (const data of body) {
+  console.log('data', data.toString('utf8')) // data foo
+}
+```
+
+#### Example - Mocked request with origin function
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+const mockPool = mockAgent.get((origin) => origin === 'http://localhost:3000')
+mockPool.intercept({ path: '/foo' }).reply(200, 'foo')
+
+const {
+  statusCode,
+  body
+} = await request('http://localhost:3000/foo')
+
+console.log('response received', statusCode) // response received 200
+
+for await (const data of body) {
+  console.log('data', data.toString('utf8')) // data foo
+}
+```
+
+### `MockAgent.close()`
+
+Closes the mock agent and waits for registered mock pools and clients to also close before resolving.
+
+Returns: `Promise<void>`
+
+#### Example - clean up after tests are complete
+
+```js
+import { MockAgent, setGlobalDispatcher } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+await mockAgent.close()
+```
+
+### `MockAgent.dispatch(options, handlers)`
+
+Implements [`Agent.dispatch(options, handlers)`](Agent.md#parameter-agentdispatchoptions).
+
+### `MockAgent.request(options[, callback])`
+
+See [`Dispatcher.request(options [, callback])`](Dispatcher.md#dispatcherrequestoptions-callback).
+
+#### Example - MockAgent request
+
+```js
+import { MockAgent } from 'undici'
+
+const mockAgent = new MockAgent()
+
+const mockPool = mockAgent.get('http://localhost:3000')
+mockPool.intercept({ path: '/foo' }).reply(200, 'foo')
+
+const {
+  statusCode,
+  body
+} = await mockAgent.request({
+  origin: 'http://localhost:3000',
+  path: '/foo',
+  method: 'GET'
+})
+
+console.log('response received', statusCode) // response received 200
+
+for await (const data of body) {
+  console.log('data', data.toString('utf8')) // data foo
+}
+```
+
+### `MockAgent.deactivate()`
+
+This method disables mocking in MockAgent.
+
+Returns: `void`
+
+#### Example - Deactivate Mocking
+
+```js
+import { MockAgent, setGlobalDispatcher } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+mockAgent.deactivate()
+```
+
+### `MockAgent.activate()`
+
+This method enables mocking in a MockAgent instance. When instantiated, a MockAgent is automatically activated. Therefore, this method is only effective after `MockAgent.deactivate` has been called.
+
+Returns: `void`
+
+#### Example - Activate Mocking
+
+```js
+import { MockAgent, setGlobalDispatcher } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+mockAgent.deactivate()
+// No mocking will occur
+
+// Later
+mockAgent.activate()
+```
+
+### `MockAgent.enableNetConnect([host])`
+
+When requests are not matched in a MockAgent intercept, a real HTTP request is attempted. We can control this further through the use of `enableNetConnect`. This is achieved by defining host matchers so only matching requests will be attempted.
+
+When using a string, it should only include the **hostname and optionally, the port**. In addition, calling this method multiple times with a string will allow all HTTP requests that match these values.
+
+Arguments:
+
+* **host** `string | RegExp | (value) => boolean` - (optional)
+
+Returns: `void`
+
+#### Example - Allow all non-matching urls to be dispatched in a real HTTP request
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+mockAgent.enableNetConnect()
+
+await request('http://example.com')
+// A real request is made
+```
+
+#### Example - Allow requests matching a host string to make real requests
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+mockAgent.enableNetConnect('example-1.com')
+mockAgent.enableNetConnect('example-2.com:8080')
+
+await request('http://example-1.com')
+// A real request is made
+
+await request('http://example-2.com:8080')
+// A real request is made
+
+await request('http://example-3.com')
+// Will throw
+```
+
+#### Example - Allow requests matching a host regex to make real requests
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+mockAgent.enableNetConnect(new RegExp('example.com'))
+
+await request('http://example.com')
+// A real request is made
+```
+
+#### Example - Allow requests matching a host function to make real requests
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+mockAgent.enableNetConnect((value) => value === 'example.com')
+
+await request('http://example.com')
+// A real request is made
+```
+
+### `MockAgent.disableNetConnect()`
+
+This method causes all requests to throw when requests are not matched in a MockAgent intercept.
+
+Returns: `void`
+
+#### Example - Disable all non-matching requests by throwing an error for each
+
+```js
+import { MockAgent, request } from 'undici'
+
+const mockAgent = new MockAgent()
+
+mockAgent.disableNetConnect()
+
+await request('http://example.com')
+// Will throw
+```
+
+### `MockAgent.pendingInterceptors()`
+
+This method returns any pending interceptors registered on a mock agent. A pending interceptor meets one of the following criteria:
+
+- Is registered with neither `.times(<number>)` nor `.persist()`, and has not been invoked;
+- Is persistent (i.e., registered with `.persist()`) and has not been invoked;
+- Is registered with `.times(<number>)` and has not been invoked `<number>` of times.
+
+Returns: `PendingInterceptor[]` (where `PendingInterceptor` is a `MockDispatch` with an additional `origin: string`)
+
+#### Example - List all pending inteceptors
+
+```js
+const agent = new MockAgent()
+agent.disableNetConnect()
+
+agent
+  .get('https://example.com')
+  .intercept({ method: 'GET', path: '/' })
+  .reply(200)
+
+const pendingInterceptors = agent.pendingInterceptors()
+// Returns [
+//   {
+//     timesInvoked: 0,
+//     times: 1,
+//     persist: false,
+//     consumed: false,
+//     pending: true,
+//     path: '/',
+//     method: 'GET',
+//     body: undefined,
+//     headers: undefined,
+//     data: {
+//       error: null,
+//       statusCode: 200,
+//       data: '',
+//       headers: {},
+//       trailers: {}
+//     },
+//     origin: 'https://example.com'
+//   }
+// ]
+```
+
+### `MockAgent.assertNoPendingInterceptors([options])`
+
+This method throws if the mock agent has any pending interceptors. A pending interceptor meets one of the following criteria:
+
+- Is registered with neither `.times(<number>)` nor `.persist()`, and has not been invoked;
+- Is persistent (i.e., registered with `.persist()`) and has not been invoked;
+- Is registered with `.times(<number>)` and has not been invoked `<number>` of times.
+
+#### Example - Check that there are no pending interceptors
+
+```js
+const agent = new MockAgent()
+agent.disableNetConnect()
+
+agent
+  .get('https://example.com')
+  .intercept({ method: 'GET', path: '/' })
+  .reply(200)
+
+agent.assertNoPendingInterceptors()
+// Throws an UndiciError with the following message:
+//
+// 1 interceptor is pending:
+//
+// ┌─────────┬────────┬───────────────────────┬──────┬─────────────┬────────────┬─────────────┬───────────┐
+// │ (index) │ Method │        Origin         │ Path │ Status code │ Persistent │ Invocations │ Remaining │
+// ├─────────┼────────┼───────────────────────┼──────┼─────────────┼────────────┼─────────────┼───────────┤
+// │    0    │ 'GET'  │ 'https://example.com' │ '/'  │     200     │    '❌'    │      0      │     1     │
+// └─────────┴────────┴───────────────────────┴──────┴─────────────┴────────────┴─────────────┴───────────┘
+```
diff --git a/docs/api/MockClient.md b/docs/api/MockClient.md
new file mode 100644
index 0000000..ac54691
--- /dev/null
+++ b/docs/api/MockClient.md
@@ -0,0 +1,77 @@
+# Class: MockClient
+
+Extends: `undici.Client`
+
+A mock client class that implements the same api as [MockPool](MockPool.md).
+
+## `new MockClient(origin, [options])`
+
+Arguments:
+
+* **origin** `string` - It should only include the **protocol, hostname, and port**.
+* **options** `MockClientOptions` - It extends the `Client` options.
+
+Returns: `MockClient`
+
+### Parameter: `MockClientOptions`
+
+Extends: `ClientOptions`
+
+* **agent** `Agent` - the agent to associate this MockClient with.
+
+### Example - Basic MockClient instantiation
+
+We can use MockAgent to instantiate a MockClient ready to be used to intercept specified requests. It will not do anything until registered as the agent to use and any mock request are registered.
+
+```js
+import { MockAgent } from 'undici'
+
+// Connections must be set to 1 to return a MockClient instance
+const mockAgent = new MockAgent({ connections: 1 })
+
+const mockClient = mockAgent.get('http://localhost:3000')
+```
+
+## Instance Methods
+
+### `MockClient.intercept(options)`
+
+Implements: [`MockPool.intercept(options)`](MockPool.md#mockpoolinterceptoptions)
+
+### `MockClient.close()`
+
+Implements: [`MockPool.close()`](MockPool.md#mockpoolclose)
+
+### `MockClient.dispatch(options, handlers)`
+
+Implements [`Dispatcher.dispatch(options, handlers)`](Dispatcher.md#dispatcherdispatchoptions-handler).
+
+### `MockClient.request(options[, callback])`
+
+See [`Dispatcher.request(options [, callback])`](Dispatcher.md#dispatcherrequestoptions-callback).
+
+#### Example - MockClient request
+
+```js
+import { MockAgent } from 'undici'
+
+const mockAgent = new MockAgent({ connections: 1 })
+
+const mockClient = mockAgent.get('http://localhost:3000')
+mockClient.intercept({ path: '/foo' }).reply(200, 'foo')
+
+const {
+  statusCode,
+  body
+} = await mockClient.request({
+  origin: 'http://localhost:3000',
+  path: '/foo',
+  method: 'GET'
+})
+
+console.log('response received', statusCode) // response received 200
+
+for await (const data of body) {
+  console.log('data', data.toString('utf8')) // data foo
+}
+```
diff --git a/docs/api/MockErrors.md b/docs/api/MockErrors.md
new file mode 100644
index 0000000..c1aa3db
--- /dev/null
+++ b/docs/api/MockErrors.md
@@ -0,0 +1,12 @@
+# MockErrors
+
+Undici exposes a variety of mock error objects that you can use to enhance your mock error handling.
+You can find all the mock error objects inside the `mockErrors` key.
+
+```js
+import { mockErrors } from 'undici'
+```
+
+| Mock Error            | Mock Error Codes                | Description                                                |
+| --------------------- | ------------------------------- | ---------------------------------------------------------- |
+| `MockNotMatchedError` | `UND_MOCK_ERR_MOCK_NOT_MATCHED` | The request does not match any registered mock dispatches. |
diff --git a/docs/api/MockPool.md b/docs/api/MockPool.md
new file mode 100644
index 0000000..96a986f
--- /dev/null
+++ b/docs/api/MockPool.md
@@ -0,0 +1,547 @@
+# Class: MockPool
+
+Extends: `undici.Pool`
+
+A mock Pool class that implements the Pool API and is used by MockAgent to intercept real requests and return mocked responses.
+
+## `new MockPool(origin, [options])`
+
+Arguments:
+
+* **origin** `string` - It should only include the **protocol, hostname, and port**.
+* **options** `MockPoolOptions` - It extends the `Pool` options.
+
+Returns: `MockPool`
+
+### Parameter: `MockPoolOptions`
+
+Extends: `PoolOptions`
+
+* **agent** `Agent` - the agent to associate this MockPool with.
+
+### Example - Basic MockPool instantiation
+
+We can use MockAgent to instantiate a MockPool ready to be used to intercept specified requests. It will not do anything until registered as the agent to use and any mock request are registered.
+
+```js
+import { MockAgent } from 'undici'
+
+const mockAgent = new MockAgent()
+
+const mockPool = mockAgent.get('http://localhost:3000')
+```
+
+## Instance Methods
+
+### `MockPool.intercept(options)`
+
+This method defines the interception rules for matching against requests for a MockPool or MockPool. We can intercept multiple times on a single instance, but each intercept is only used once. For example if you expect to make 2 requests inside a test, you need to call `intercept()` twice. Assuming you use `disableNetConnect()` you will get `MockNotMatchedError` on the second request when you only call `intercept()` once.
+
+When defining interception rules, all the rules must pass for a request to be intercepted. If a request is not intercepted, a real request will be attempted.
+
+| Matcher type | Condition to pass          |
+|:------------:| -------------------------- |
+| `string`     | Exact match against string |
+| `RegExp`     | Regex must pass            |
+| `Function`   | Function must return true  |
+
+Arguments:
+
+* **options** `MockPoolInterceptOptions` - Interception options.
+
+Returns: `MockInterceptor` corresponding to the input options.
+
+### Parameter: `MockPoolInterceptOptions`
+
+* **path** `string | RegExp | (path: string) => boolean` - a matcher for the HTTP request path. When a `RegExp` or callback is used, it will match against the request path including all query parameters in alphabetical order. When a `string` is provided, the query parameters can be conveniently specified through the `MockPoolInterceptOptions.query` setting.
+* **method** `string | RegExp | (method: string) => boolean` - (optional) - a matcher for the HTTP request method. Defaults to `GET`.
+* **body** `string | RegExp | (body: string) => boolean` - (optional) - a matcher for the HTTP request body.
+* **headers** `Record<string, string | RegExp | (body: string) => boolean`> - (optional) - a matcher for the HTTP request headers. To be intercepted, a request must match all defined headers. Extra headers not defined here may (or may not) be included in the request and do not affect the interception in any way.
+* **query** `Record<string, any> | null` - (optional) - a matcher for the HTTP request query string params. Only applies when a `string` was provided for `MockPoolInterceptOptions.path`.
+
+### Return: `MockInterceptor`
+
+We can define the behaviour of an intercepted request with the following options.
+
+* **reply** `(statusCode: number, replyData: string | Buffer | object | MockInterceptor.MockResponseDataHandler, responseOptions?: MockResponseOptions) => MockScope` - define a reply for a matching request. You can define the replyData as a callback to read incoming request data. Default for `responseOptions` is `{}`.
+* **reply** `(callback: MockInterceptor.MockReplyOptionsCallback) => MockScope` - define a reply for a matching request, allowing dynamic mocking of all reply options rather than just the data.
+* **replyWithError** `(error: Error) => MockScope` - define an error for a matching request to throw.
+* **defaultReplyHeaders** `(headers: Record<string, string>) => MockInterceptor` - define default headers to be included in subsequent replies. These are in addition to headers on a specific reply.
+* **defaultReplyTrailers** `(trailers: Record<string, string>) => MockInterceptor` - define default trailers to be included in subsequent replies. These are in addition to trailers on a specific reply.
+* **replyContentLength** `() => MockInterceptor` - define automatically calculated `content-length` headers to be included in subsequent replies.
+
+The reply data of an intercepted request may either be a string, buffer, or JavaScript object. Objects are converted to JSON while strings and buffers are sent as-is.
+
+By default, `reply` and `replyWithError` define the behaviour for the first matching request only. Subsequent requests will not be affected (this can be changed using the returned `MockScope`).
+
+### Parameter: `MockResponseOptions`
+
+* **headers** `Record<string, string>` - headers to be included on the mocked reply.
+* **trailers** `Record<string, string>` - trailers to be included on the mocked reply.
+
+### Return: `MockScope`
+
+A `MockScope` is associated with a single `MockInterceptor`. With this, we can configure the default behaviour of a intercepted reply.
+
+* **delay** `(waitInMs: number) => MockScope` - delay the associated reply by a set amount in ms.
+* **persist** `() => MockScope` - any matching request will always reply with the defined response indefinitely.
+* **times** `(repeatTimes: number) => MockScope` - any matching request will reply with the defined response a fixed amount of times. This is overridden by **persist**.
+
+#### Example - Basic Mocked Request
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+// MockPool
+const mockPool = mockAgent.get('http://localhost:3000')
+mockPool.intercept({ path: '/foo' }).reply(200, 'foo')
+
+const {
+  statusCode,
+  body
+} = await request('http://localhost:3000/foo')
+
+console.log('response received', statusCode) // response received 200
+
+for await (const data of body) {
+  console.log('data', data.toString('utf8')) // data foo
+}
+```
+
+#### Example - Mocked request using reply data callbacks
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+const mockPool = mockAgent.get('http://localhost:3000')
+
+mockPool.intercept({
+  path: '/echo',
+  method: 'GET',
+  headers: {
+    'User-Agent': 'undici',
+    Host: 'example.com'
+  }
+}).reply(200, ({ headers }) => ({ message: headers.get('message') }))
+
+const { statusCode, body, headers } = await request('http://localhost:3000', {
+  headers: {
+    message: 'hello world!'
+  }
+})
+
+console.log('response received', statusCode) // response received 200
+console.log('headers', headers) // { 'content-type': 'application/json' }
+
+for await (const data of body) {
+  console.log('data', data.toString('utf8')) // { "message":"hello world!" }
+}
+```
+
+#### Example - Mocked request using reply options callback
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+const mockPool = mockAgent.get('http://localhost:3000')
+
+mockPool.intercept({
+  path: '/echo',
+  method: 'GET',
+  headers: {
+    'User-Agent': 'undici',
+    Host: 'example.com'
+  }
+}).reply(({ headers }) => ({ statusCode: 200, data: { message: headers.get('message') }})))
+
+const { statusCode, body, headers } = await request('http://localhost:3000', {
+  headers: {
+    message: 'hello world!'
+  }
+})
+
+console.log('response received', statusCode) // response received 200
+console.log('headers', headers) // { 'content-type': 'application/json' }
+
+for await (const data of body) {
+  console.log('data', data.toString('utf8')) // { "message":"hello world!" }
+}
+```
+
+#### Example - Basic Mocked requests with multiple intercepts
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+const mockPool = mockAgent.get('http://localhost:3000')
+
+mockPool.intercept({
+  path: '/foo',
+  method: 'GET'
+}).reply(200, 'foo')
+
+mockPool.intercept({
+  path: '/hello',
+  method: 'GET',
+}).reply(200, 'hello')
+
+const result1 = await request('http://localhost:3000/foo')
+
+console.log('response received', result1.statusCode) // response received 200
+
+for await (const data of result1.body) {
+  console.log('data', data.toString('utf8')) // data foo
+}
+
+const result2 = await request('http://localhost:3000/hello')
+
+console.log('response received', result2.statusCode) // response received 200
+
+for await (const data of result2.body) {
+  console.log('data', data.toString('utf8')) // data hello
+}
+```
+
+#### Example - Mocked request with query body, request headers and response headers and trailers
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+const mockPool = mockAgent.get('http://localhost:3000')
+
+mockPool.intercept({
+  path: '/foo?hello=there&see=ya',
+  method: 'POST',
+  body: 'form1=data1&form2=data2',
+  headers: {
+    'User-Agent': 'undici',
+    Host: 'example.com'
+  }
+}).reply(200, { foo: 'bar' }, {
+  headers: { 'content-type': 'application/json' },
+  trailers: { 'Content-MD5': 'test' }
+})
+
+const {
+  statusCode,
+  headers,
+  trailers,
+  body
+} = await request('http://localhost:3000/foo?hello=there&see=ya', {
+    method: 'POST',
+    body: 'form1=data1&form2=data2',
+    headers: {
+      foo: 'bar',
+      'User-Agent': 'undici',
+      Host: 'example.com'
+    }
+  })
+
+console.log('response received', statusCode) // response received 200
+console.log('headers', headers) // { 'content-type': 'application/json' }
+
+for await (const data of body) {
+  console.log('data', data.toString('utf8')) // '{"foo":"bar"}'
+}
+
+console.log('trailers', trailers) // { 'content-md5': 'test' }
+```
+
+#### Example - Mocked request using different matchers
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+const mockPool = mockAgent.get('http://localhost:3000')
+
+mockPool.intercept({
+  path: '/foo',
+  method: /^GET$/,
+  body: (value) => value === 'form=data',
+  headers: {
+    'User-Agent': 'undici',
+    Host: /^example.com$/
+  }
+}).reply(200, 'foo')
+
+const {
+  statusCode,
+  body
+} = await request('http://localhost:3000/foo', {
+  method: 'GET',
+  body: 'form=data',
+  headers: {
+    foo: 'bar',
+    'User-Agent': 'undici',
+    Host: 'example.com'
+  }
+})
+
+console.log('response received', statusCode) // response received 200
+
+for await (const data of body) {
+  console.log('data', data.toString('utf8')) // data foo
+}
+```
+
+#### Example - Mocked request with reply with a defined error
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+const mockPool = mockAgent.get('http://localhost:3000')
+
+mockPool.intercept({
+  path: '/foo',
+  method: 'GET'
+}).replyWithError(new Error('kaboom'))
+
+try {
+  await request('http://localhost:3000/foo', {
+    method: 'GET'
+  })
+} catch (error) {
+  console.error(error) // Error: kaboom
+}
+```
+
+#### Example - Mocked request with defaultReplyHeaders
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+const mockPool = mockAgent.get('http://localhost:3000')
+
+mockPool.intercept({
+  path: '/foo',
+  method: 'GET'
+}).defaultReplyHeaders({ foo: 'bar' })
+  .reply(200, 'foo')
+
+const { headers } = await request('http://localhost:3000/foo')
+
+console.log('headers', headers) // headers { foo: 'bar' }
+```
+
+#### Example - Mocked request with defaultReplyTrailers
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+const mockPool = mockAgent.get('http://localhost:3000')
+
+mockPool.intercept({
+  path: '/foo',
+  method: 'GET'
+}).defaultReplyTrailers({ foo: 'bar' })
+  .reply(200, 'foo')
+
+const { trailers } = await request('http://localhost:3000/foo')
+
+console.log('trailers', trailers) // trailers { foo: 'bar' }
+```
+
+#### Example - Mocked request with automatic content-length calculation
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+const mockPool = mockAgent.get('http://localhost:3000')
+
+mockPool.intercept({
+  path: '/foo',
+  method: 'GET'
+}).replyContentLength().reply(200, 'foo')
+
+const { headers } = await request('http://localhost:3000/foo')
+
+console.log('headers', headers) // headers { 'content-length': '3' }
+```
+
+#### Example - Mocked request with automatic content-length calculation on an object
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+const mockPool = mockAgent.get('http://localhost:3000')
+
+mockPool.intercept({
+  path: '/foo',
+  method: 'GET'
+}).replyContentLength().reply(200, { foo: 'bar' })
+
+const { headers } = await request('http://localhost:3000/foo')
+
+console.log('headers', headers) // headers { 'content-length': '13' }
+```
+
+#### Example - Mocked request with persist enabled
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+const mockPool = mockAgent.get('http://localhost:3000')
+
+mockPool.intercept({
+  path: '/foo',
+  method: 'GET'
+}).reply(200, 'foo').persist()
+
+const result1 = await request('http://localhost:3000/foo')
+// Will match and return mocked data
+
+const result2 = await request('http://localhost:3000/foo')
+// Will match and return mocked data
+
+// Etc
+```
+
+#### Example - Mocked request with times enabled
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+const mockPool = mockAgent.get('http://localhost:3000')
+
+mockPool.intercept({
+  path: '/foo',
+  method: 'GET'
+}).reply(200, 'foo').times(2)
+
+const result1 = await request('http://localhost:3000/foo')
+// Will match and return mocked data
+
+const result2 = await request('http://localhost:3000/foo')
+// Will match and return mocked data
+
+const result3 = await request('http://localhost:3000/foo')
+// Will not match and make attempt a real request
+```
+
+#### Example - Mocked request with path callback
+
+```js
+import { MockAgent, setGlobalDispatcher, request } from 'undici'
+import querystring from 'querystring'
+
+const mockAgent = new MockAgent()
+setGlobalDispatcher(mockAgent)
+
+const mockPool = mockAgent.get('http://localhost:3000')
+
+const matchPath = requestPath => {
+  const [pathname, search] = requestPath.split('?')
+  const requestQuery = querystring.parse(search)
+
+  if (!pathname.startsWith('/foo')) {
+    return false
+  }
+
+  if (!Object.keys(requestQuery).includes('foo') || requestQuery.foo !== 'bar') {
+    return false
+  }
+
+  return true
+}
+
+mockPool.intercept({
+  path: matchPath,
+  method: 'GET'
+}).reply(200, 'foo')
+
+const result = await request('http://localhost:3000/foo?foo=bar')
+// Will match and return mocked data
+```
+
+### `MockPool.close()`
+
+Closes the mock pool and de-registers from associated MockAgent.
+
+Returns: `Promise<void>`
+
+#### Example - clean up after tests are complete
+
+```js
+import { MockAgent } from 'undici'
+
+const mockAgent = new MockAgent()
+const mockPool = mockAgent.get('http://localhost:3000')
+
+await mockPool.close()
+```
+
+### `MockPool.dispatch(options, handlers)`
+
+Implements [`Dispatcher.dispatch(options, handlers)`](Dispatcher.md#dispatcherdispatchoptions-handler).
+
+### `MockPool.request(options[, callback])`
+
+See [`Dispatcher.request(options [, callback])`](Dispatcher.md#dispatcherrequestoptions-callback).
+
+#### Example - MockPool request
+
+```js
+import { MockAgent } from 'undici'
+
+const mockAgent = new MockAgent()
+
+const mockPool = mockAgent.get('http://localhost:3000')
+mockPool.intercept({
+  path: '/foo',
+  method: 'GET',
+}).reply(200, 'foo')
+
+const {
+  statusCode,
+  body
+} = await mockPool.request({
+  origin: 'http://localhost:3000',
+  path: '/foo',
+  method: 'GET'
+})
+
+console.log('response received', statusCode) // response received 200
+
+for await (const data of body) {
+  console.log('data', data.toString('utf8')) // data foo
+}
+```
diff --git a/docs/api/Pool.md b/docs/api/Pool.md
new file mode 100644
index 0000000..8fcabac
--- /dev/null
+++ b/docs/api/Pool.md
@@ -0,0 +1,84 @@
+# Class: Pool
+
+Extends: `undici.Dispatcher`
+
+A pool of [Client](Client.md) instances connected to the same upstream target.
+
+Requests are not guaranteed to be dispatched in order of invocation.
+
+## `new Pool(url[, options])`
+
+Arguments:
+
+* **url** `URL | string` - It should only include the **protocol, hostname, and port**.
+* **options** `PoolOptions` (optional)
+
+### Parameter: `PoolOptions`
+
+Extends: [`ClientOptions`](Client.md#parameter-clientoptions)
+
+* **factory** `(origin: URL, opts: Object) => Dispatcher` - Default: `(origin, opts) => new Client(origin, opts)`
+* **connections** `number | null` (optional) - Default: `null` - The number of `Client` instances to create. When set to `null`, the `Pool` instance will create an unlimited amount of `Client` instances.
+* **interceptors** `{ Pool: DispatchInterceptor[] } }` - Default: `{ Pool: [] }` - A list of interceptors that are applied to the dispatch method. Additional logic can be applied (such as, but not limited to: 302 status code handling, authentication, cookies, compression and caching).
+
+## Instance Properties
+
+### `Pool.closed`
+
+Implements [Client.closed](Client.md#clientclosed)
+
+### `Pool.destroyed`
+
+Implements [Client.destroyed](Client.md#clientdestroyed)
+
+### `Pool.stats`
+
+Returns [`PoolStats`](PoolStats.md) instance for this pool.
+
+## Instance Methods
+
+### `Pool.close([callback])`
+
+Implements [`Dispatcher.close([callback])`](Dispatcher.md#dispatcherclosecallback-promise).
+
+### `Pool.destroy([error, callback])`
+
+Implements [`Dispatcher.destroy([error, callback])`](Dispatcher.md#dispatcherdestroyerror-callback-promise).
+
+### `Pool.connect(options[, callback])`
+
+See [`Dispatcher.connect(options[, callback])`](Dispatcher.md#dispatcherconnectoptions-callback).
+
+### `Pool.dispatch(options, handler)`
+
+Implements [`Dispatcher.dispatch(options, handler)`](Dispatcher.md#dispatcherdispatchoptions-handler).
+
+### `Pool.pipeline(options, handler)`
+
+See [`Dispatcher.pipeline(options, handler)`](Dispatcher.md#dispatcherpipelineoptions-handler).
+
+### `Pool.request(options[, callback])`
+
+See [`Dispatcher.request(options [, callback])`](Dispatcher.md#dispatcherrequestoptions-callback).
+
+### `Pool.stream(options, factory[, callback])`
+
+See [`Dispatcher.stream(options, factory[, callback])`](Dispatcher.md#dispatcherstreamoptions-factory-callback).
+
+### `Pool.upgrade(options[, callback])`
+
+See [`Dispatcher.upgrade(options[, callback])`](Dispatcher.md#dispatcherupgradeoptions-callback).
+
+## Instance Events
+
+### Event: `'connect'`
+
+See [Dispatcher Event: `'connect'`](Dispatcher.md#event-connect).
+
+### Event: `'disconnect'`
+
+See [Dispatcher Event: `'disconnect'`](Dispatcher.md#event-disconnect).
+
+### Event: `'drain'`
+
+See [Dispatcher Event: `'drain'`](Dispatcher.md#event-drain).
diff --git a/docs/api/PoolStats.md b/docs/api/PoolStats.md
new file mode 100644
index 0000000..16b6dc2
--- /dev/null
+++ b/docs/api/PoolStats.md
@@ -0,0 +1,35 @@
+# Class: PoolStats
+
+Aggregate stats for a [Pool](Pool.md) or [BalancedPool](BalancedPool.md).
+
+## `new PoolStats(pool)`
+
+Arguments:
+
+* **pool** `Pool` - Pool or BalancedPool from which to return stats.
+
+## Instance Properties
+
+### `PoolStats.connected`
+
+Number of open socket connections in this pool.
+
+### `PoolStats.free`
+
+Number of open socket connections in this pool that do not have an active request.
+
+### `PoolStats.pending`
+
+Number of pending requests across all clients in this pool.
+
+### `PoolStats.queued`
+
+Number of queued requests across all clients in this pool.
+
+### `PoolStats.running`
+
+Number of currently active requests across all clients in this pool.
+
+### `PoolStats.size`
+
+Number of active, pending, or queued requests across all clients in this pool.
diff --git a/docs/api/ProxyAgent.md b/docs/api/ProxyAgent.md
new file mode 100644
index 0000000..cebfe68
--- /dev/null
+++ b/docs/api/ProxyAgent.md
@@ -0,0 +1,126 @@
+# Class: ProxyAgent
+
+Extends: `undici.Dispatcher`
+
+A Proxy Agent class that implements the Agent API. It allows the connection through proxy in a simple way.
+
+## `new ProxyAgent([options])`
+
+Arguments:
+
+* **options** `ProxyAgentOptions` (required) - It extends the `Agent` options.
+
+Returns: `ProxyAgent`
+
+### Parameter: `ProxyAgentOptions`
+
+Extends: [`AgentOptions`](Agent.md#parameter-agentoptions)
+
+* **uri** `string` (required) - It can be passed either by a string or a object containing `uri` as string.
+* **token** `string` (optional) - It can be passed by a string of token for authentication.
+* **auth** `string` (**deprecated**) - Use token.
+* **clientFactory** `(origin: URL, opts: Object) => Dispatcher` (optional) - Default: `(origin, opts) => new Pool(origin, opts)`
+* **requestTls** `BuildOptions` (optional) - Options object passed when creating the underlying socket via the connector builder for the request. See [TLS](https://nodejs.org/api/tls.html#tlsconnectoptions-callback).
+* **proxyTls** `BuildOptions` (optional) - Options object passed when creating the underlying socket via the connector builder for the proxy server. See [TLS](https://nodejs.org/api/tls.html#tlsconnectoptions-callback).
+
+Examples:
+
+```js
+import { ProxyAgent } from 'undici'
+
+const proxyAgent = new ProxyAgent('my.proxy.server')
+// or
+const proxyAgent = new ProxyAgent({ uri: 'my.proxy.server' })
+```
+
+#### Example - Basic ProxyAgent instantiation
+
+This will instantiate the ProxyAgent. It will not do anything until registered as the agent to use with requests.
+
+```js
+import { ProxyAgent } from 'undici'
+
+const proxyAgent = new ProxyAgent('my.proxy.server')
+```
+
+#### Example - Basic Proxy Request with global agent dispatcher
+
+```js
+import { setGlobalDispatcher, request, ProxyAgent } from 'undici'
+
+const proxyAgent = new ProxyAgent('my.proxy.server')
+setGlobalDispatcher(proxyAgent)
+
+const { statusCode, body } = await request('http://localhost:3000/foo')
+
+console.log('response received', statusCode) // response received 200
+
+for await (const data of body) {
+  console.log('data', data.toString('utf8')) // data foo
+}
+```
+
+#### Example - Basic Proxy Request with local agent dispatcher
+
+```js
+import { ProxyAgent, request } from 'undici'
+
+const proxyAgent = new ProxyAgent('my.proxy.server')
+
+const {
+  statusCode,
+  body
+} = await request('http://localhost:3000/foo', { dispatcher: proxyAgent })
+
+console.log('response received', statusCode) // response received 200
+
+for await (const data of body) {
+  console.log('data', data.toString('utf8')) // data foo
+}
+```
+
+#### Example - Basic Proxy Request with authentication
+
+```js
+import { setGlobalDispatcher, request, ProxyAgent } from 'undici';
+
+const proxyAgent = new ProxyAgent({
+  uri: 'my.proxy.server',
+  // token: 'Bearer xxxx'
+  token: `Basic ${Buffer.from('username:password').toString('base64')}`
+});
+setGlobalDispatcher(proxyAgent);
+
+const { statusCode, body } = await request('http://localhost:3000/foo');
+
+console.log('response received', statusCode); // response received 200
+
+for await (const data of body) {
+  console.log('data', data.toString('utf8')); // data foo
+}
+```
+
+### `ProxyAgent.close()`
+
+Closes the proxy agent and waits for registered pools and clients to also close before resolving.
+
+Returns: `Promise<void>`
+
+#### Example - clean up after tests are complete
+
+```js
+import { ProxyAgent, setGlobalDispatcher } from 'undici'
+
+const proxyAgent = new ProxyAgent('my.proxy.server')
+setGlobalDispatcher(proxyAgent)
+
+await proxyAgent.close()
+```
+
+### `ProxyAgent.dispatch(options, handlers)`
+
+Implements [`Agent.dispatch(options, handlers)`](Agent.md#parameter-agentdispatchoptions).
+
+### `ProxyAgent.request(options[, callback])`
+
+See [`Dispatcher.request(options [, callback])`](Dispatcher.md#dispatcherrequestoptions-callback).
diff --git a/docs/api/RetryHandler.md b/docs/api/RetryHandler.md
new file mode 100644
index 0000000..2323ce4
--- /dev/null
+++ b/docs/api/RetryHandler.md
@@ -0,0 +1,108 @@
+# Class: RetryHandler
+
+Extends: `undici.DispatcherHandlers`
+
+A handler class that implements the retry logic for a request.
+
+## `new RetryHandler(dispatchOptions, retryHandlers, [retryOptions])`
+
+Arguments:
+
+- **options** `Dispatch.DispatchOptions & RetryOptions` (required) - It is an intersection of `Dispatcher.DispatchOptions` and `RetryOptions`.
+- **retryHandlers** `RetryHandlers` (required) - Object containing the `dispatch` to be used on every retry, and `handler` for handling the `dispatch` lifecycle.
+
+Returns: `retryHandler`
+
+### Parameter: `Dispatch.DispatchOptions & RetryOptions`
+
+Extends: [`Dispatch.DispatchOptions`](Dispatcher.md#parameter-dispatchoptions).
+
+#### `RetryOptions`
+
+- **retry** `(err: Error, context: RetryContext, callback: (err?: Error | null) => void) => void` (optional) - Function to be called after every retry. It should pass error if no more retries should be performed.
+- **maxRetries** `number` (optional) - Maximum number of retries. Default: `5`
+- **maxTimeout** `number` (optional) - Maximum number of milliseconds to wait before retrying. Default: `30000` (30 seconds)
+- **minTimeout** `number` (optional) - Minimum number of milliseconds to wait before retrying. Default: `500` (half a second)
+- **timeoutFactor** `number` (optional) - Factor to multiply the timeout by for each retry attempt. Default: `2`
+- **retryAfter** `boolean` (optional) - It enables automatic retry after the `Retry-After` header is received. Default: `true`
+-
+- **methods** `string[]` (optional) - Array of HTTP methods to retry. Default: `['GET', 'PUT', 'HEAD', 'OPTIONS', 'DELETE']`
+- **statusCodes** `number[]` (optional) - Array of HTTP status codes to retry. Default: `[429, 500, 502, 503, 504]`
+- **errorCodes** `string[]` (optional) - Array of Error codes to retry. Default: `['ECONNRESET', 'ECONNREFUSED', 'ENOTFOUND', 'ENETDOWN','ENETUNREACH', 'EHOSTDOWN',
+
+**`RetryContext`**
+
+- `state`: `RetryState` - Current retry state. It can be mutated.
+- `opts`: `Dispatch.DispatchOptions & RetryOptions` - Options passed to the retry handler.
+
+### Parameter `RetryHandlers`
+
+- **dispatch** `(options: Dispatch.DispatchOptions, handlers: Dispatch.DispatchHandlers) => Promise<Dispatch.DispatchResponse>` (required) - Dispatch function to be called after every retry.
+- **handler** Extends [`Dispatch.DispatchHandlers`](Dispatcher.md#dispatcherdispatchoptions-handler) (required) - Handler function to be called after the request is successful or the retries are exhausted.
+
+Examples:
+
+```js
+const client = new Client(`http://localhost:${server.address().port}`);
+const chunks = [];
+const handler = new RetryHandler(
+  {
+    ...dispatchOptions,
+    retryOptions: {
+      // custom retry function
+      retry: function (err, state, callback) {
+        counter++;
+
+        if (err.code && err.code === "UND_ERR_DESTROYED") {
+          callback(err);
+          return;
+        }
+
+        if (err.statusCode === 206) {
+          callback(err);
+          return;
+        }
+
+        setTimeout(() => callback(null), 1000);
+      },
+    },
+  },
+  {
+    dispatch: (...args) => {
+      return client.dispatch(...args);
+    },
+    handler: {
+      onConnect() {},
+      onBodySent() {},
+      onHeaders(status, _rawHeaders, resume, _statusMessage) {
+        // do something with headers
+      },
+      onData(chunk) {
+        chunks.push(chunk);
+        return true;
+      },
+      onComplete() {},
+      onError() {
+        // handle error properly
+      },
+    },
+  }
+);
+```
+
+#### Example - Basic RetryHandler with defaults
+
+```js
+const client = new Client(`http://localhost:${server.address().port}`);
+const handler = new RetryHandler(dispatchOptions, {
+  dispatch: client.dispatch.bind(client),
+  handler: {
+    onConnect() {},
+    onBodySent() {},
+    onHeaders(status, _rawHeaders, resume, _statusMessage) {},
+    onData(chunk) {},
+    onComplete() {},
+    onError(err) {},
+  },
+});
+```
diff --git a/docs/api/WebSocket.md b/docs/api/WebSocket.md
new file mode 100644
index 0000000..9d374f4
--- /dev/null
+++ b/docs/api/WebSocket.md
@@ -0,0 +1,43 @@
+# Class: WebSocket
+
+> ⚠️ Warning: the WebSocket API is experimental.
+
+Extends: [`EventTarget`](https://developer.mozilla.org/en-US/docs/Web/API/EventTarget)
+
+The WebSocket object provides a way to manage a WebSocket connection to a server, allowing bidirectional communication. The API follows the [WebSocket spec](https://developer.mozilla.org/en-US/docs/Web/API/WebSocket) and [RFC 6455](https://datatracker.ietf.org/doc/html/rfc6455).
+
+## `new WebSocket(url[, protocol])`
+
+Arguments:
+
+* **url** `URL | string` - The url's protocol *must* be `ws` or `wss`.
+* **protocol** `string | string[] | WebSocketInit` (optional) - Subprotocol(s) to request the server use, or a [`Dispatcher`](./Dispatcher.md).
+
+### Example:
+
+This example will not work in browsers or other platforms that don't allow passing an object.
+
+```mjs
+import { WebSocket, ProxyAgent } from 'undici'
+
+const proxyAgent = new ProxyAgent('my.proxy.server')
+
+const ws = new WebSocket('wss://echo.websocket.events', {
+  dispatcher: proxyAgent,
+  protocols: ['echo', 'chat']
+})
+```
+
+If you do not need a custom Dispatcher, it's recommended to use the following pattern:
+
+```mjs
+import { WebSocket } from 'undici'
+
+const ws = new WebSocket('wss://echo.websocket.events', ['echo', 'chat'])
+```
+
+## Read More
+
+- [MDN - WebSocket](https://developer.mozilla.org/en-US/docs/Web/API/WebSocket)
+- [The WebSocket Specification](https://www.rfc-editor.org/rfc/rfc6455)
+- [The WHATWG WebSocket Specification](https://websockets.spec.whatwg.org/)
diff --git a/docs/api/api-lifecycle.md b/docs/api/api-lifecycle.md
new file mode 100644
index 0000000..d158126
--- /dev/null
+++ b/docs/api/api-lifecycle.md
@@ -0,0 +1,62 @@
+# Client Lifecycle
+
+An Undici [Client](Client.md) can be best described as a state machine. The following list is a summary of the various state transitions the `Client` will go through in its lifecycle. This document also contains detailed breakdowns of each state.
+
+> This diagram is not a perfect representation of the undici Client. Since the Client class is not actually implemented as a state-machine, actual execution may deviate slightly from what is described below. Consider this as a general resource for understanding the inner workings of the Undici client rather than some kind of formal specification.
+
+## State Transition Overview
+
+* A `Client` begins in the **idle** state with no socket connection and no requests in queue.
+  * The *connect* event transitions the `Client` to the **pending** state where requests can be queued prior to processing.
+  * The *close* and *destroy* events transition the `Client` to the **destroyed** state. Since there are no requests in the queue, the *close* event immediately transitions to the **destroyed** state.
+* The **pending** state indicates the underlying socket connection has been successfully established and requests are queueing.
+  * The *process* event transitions the `Client` to the **processing** state where requests are processed.
+  * If requests are queued, the *close* event transitions to the **processing** state; otherwise, it transitions to the **destroyed** state.
+  * The *destroy* event transitions to the **destroyed** state.
+* The **processing** state initializes to the **processing.running** state.
+  * If the current request requires draining, the *needDrain* event transitions the `Client` into the **processing.busy** state which will return to the **processing.running** state with the *drainComplete* event.
+  * After all queued requests are completed, the *keepalive* event transitions the `Client` back to the **pending** state. If no requests are queued during the timeout, the **close** event transitions the `Client` to the **destroyed** state.
+  * If the *close* event is fired while the `Client` still has queued requests, the `Client` transitions to the **process.closing** state where it will complete all existing requests before firing the *done* event.
+  * The *done* event gracefully transitions the `Client` to the **destroyed** state.
+  * At any point in time, the *destroy* event will transition the `Client` from the **processing** state to the **destroyed** state, destroying any queued requests.
+* The **destroyed** state is a final state and the `Client` is no longer functional.
+
+![A state diagram representing an Undici Client instance](../assets/lifecycle-diagram.png)
+
+> The diagram was generated using Mermaid.js Live Editor. Modify the state diagram [here](https://mermaid-js.github.io/mermaid-live-editor/#/edit/eyJjb2RlIjoic3RhdGVEaWFncmFtLXYyXG4gICAgWypdIC0tPiBpZGxlXG4gICAgaWRsZSAtLT4gcGVuZGluZyA6IGNvbm5lY3RcbiAgICBpZGxlIC0tPiBkZXN0cm95ZWQgOiBkZXN0cm95L2Nsb3NlXG4gICAgXG4gICAgcGVuZGluZyAtLT4gaWRsZSA6IHRpbWVvdXRcbiAgICBwZW5kaW5nIC0tPiBkZXN0cm95ZWQgOiBkZXN0cm95XG5cbiAgICBzdGF0ZSBjbG9zZV9mb3JrIDw8Zm9yaz4-XG4gICAgcGVuZGluZyAtLT4gY2xvc2VfZm9yayA6IGNsb3NlXG4gICAgY2xvc2VfZm9yayAtLT4gcHJvY2Vzc2luZ1xuICAgIGNsb3NlX2ZvcmsgLS0-IGRlc3Ryb3llZFxuXG4gICAgcGVuZGluZyAtLT4gcHJvY2Vzc2luZyA6IHByb2Nlc3NcblxuICAgIHByb2Nlc3NpbmcgLS0-IHBlbmRpbmcgOiBrZWVwYWxpdmVcbiAgICBwcm9jZXNzaW5nIC0tPiBkZXN0cm95ZWQgOiBkb25lXG4gICAgcHJvY2Vzc2luZyAtLT4gZGVzdHJveWVkIDogZGVzdHJveVxuXG4gICAgc3RhdGUgcHJvY2Vzc2luZyB7XG4gICAgICAgIHJ1bm5pbmcgLS0-IGJ1c3kgOiBuZWVkRHJhaW5cbiAgICAgICAgYnVzeSAtLT4gcnVubmluZyA6IGRyYWluQ29tcGxldGVcbiAgICAgICAgcnVubmluZyAtLT4gWypdIDoga2VlcGFsaXZlXG4gICAgICAgIHJ1bm5pbmcgLS0-IGNsb3NpbmcgOiBjbG9zZVxuICAgICAgICBjbG9zaW5nIC0tPiBbKl0gOiBkb25lXG4gICAgICAgIFsqXSAtLT4gcnVubmluZ1xuICAgIH1cbiAgICAiLCJtZXJtYWlkIjp7InRoZW1lIjoiYmFzZSJ9LCJ1cGRhdGVFZGl0b3IiOmZhbHNlfQ)
+
+## State details
+
+### idle
+
+The **idle** state is the initial state of a `Client` instance. While an `origin` is required for instantiating a `Client` instance, the underlying socket connection will not be established until a request is queued using [`Client.dispatch()`](Client.md#clientdispatchoptions-handlers). By calling `Client.dispatch()` directly or using one of the multiple implementations ([`Client.connect()`](Client.md#clientconnectoptions-callback), [`Client.pipeline()`](Client.md#clientpipelineoptions-handler), [`Client.request()`](Client.md#clientrequestoptions-callback), [`Client.stream()`](Client.md#clientstreamoptions-factory-callback), and [`Client.upgrade()`](Client.md#clientupgradeoptions-callback)), the `Client` instance will transition from **idle** to [**pending**](#pending) and then most likely directly to [**processing**](#processing).
+
+Calling [`Client.close()`](Client.md#clientclosecallback) or [`Client.destroy()`](Client.md#clientdestroyerror-callback) transitions directly to the [**destroyed**](#destroyed) state since the `Client` instance will have no queued requests in this state.
+
+### pending
+
+The **pending** state signifies a non-processing `Client`. Upon entering this state, the `Client` establishes a socket connection and emits the [`'connect'`](Client.md#event-connect) event signalling a connection was successfully established with the `origin` provided during `Client` instantiation. The internal queue is initially empty, and requests can start queueing.
+
+Calling [`Client.close()`](Client.md#clientclosecallback) with queued requests, transitions the `Client` to the [**processing**](#processing) state. Without queued requests, it transitions to the [**destroyed**](#destroyed) state.
+
+Calling [`Client.destroy()`](Client.md#clientdestroyerror-callback) transitions directly to the [**destroyed**](#destroyed) state regardless of existing requests.
+
+### processing
+
+The **processing** state is a state machine within itself. It initializes to the [**processing.running**](#running) state. The [`Client.dispatch()`](Client.md#clientdispatchoptions-handlers), [`Client.close()`](Client.md#clientclosecallback), and [`Client.destroy()`](Client.md#clientdestroyerror-callback) can be called at any time while the `Client` is in this state. `Client.dispatch()` will add more requests to the queue while existing requests continue to be processed. `Client.close()` will transition to the [**processing.closing**](#closing) state. And `Client.destroy()` will transition to [**destroyed**](#destroyed).
+
+#### running
+
+In the **processing.running** sub-state, queued requests are being processed in a FIFO order. If a request body requires draining, the *needDrain* event transitions to the [**processing.busy**](#busy) sub-state. The *close* event transitions the Client to the [**process.closing**](#closing) sub-state. If all queued requests are processed and neither [`Client.close()`](Client.md#clientclosecallback) nor [`Client.destroy()`](Client.md#clientdestroyerror-callback) are called, then the [**processing**](#processing) machine will trigger a *keepalive* event transitioning the `Client` back to the [**pending**](#pending) state. During this time, the `Client` is waiting for the socket connection to timeout, and once it does, it triggers the *timeout* event and transitions to the [**idle**](#idle) state.
+
+#### busy
+
+This sub-state is only entered when a request body is an instance of [Stream](https://nodejs.org/api/stream.html) and requires draining. The `Client` cannot process additional requests while in this state and must wait until the currently processing request body is completely drained before transitioning back to [**processing.running**](#running).
+
+#### closing
+
+This sub-state is only entered when a `Client` instance has queued requests and the [`Client.close()`](Client.md#clientclosecallback) method is called. In this state, the `Client` instance continues to process requests as usual, with the one exception that no additional requests can be queued. Once all of the queued requests are processed, the `Client` will trigger the *done* event gracefully entering the [**destroyed**](#destroyed) state without an error.
+
+### destroyed
+
+The **destroyed** state is a final state for the `Client` instance. Once in this state, a `Client` is nonfunctional. Calling any other `Client` methods will result in an `ClientDestroyedError`.
diff --git a/docs/assets/lifecycle-diagram.png b/docs/assets/lifecycle-diagram.png
new file mode 100644
index 0000000..4ef17b5
--- /dev/null
+++ b/docs/assets/lifecycle-diagram.png
diff --git a/docs/best-practices/client-certificate.md b/docs/best-practices/client-certificate.md
new file mode 100644
index 0000000..4fc84ec
--- /dev/null
+++ b/docs/best-practices/client-certificate.md
@@ -0,0 +1,64 @@
+# Client certificate
+
+Client certificate authentication can be configured with the `Client`, the required options are passed along through the `connect` option.
+
+The client certificates must be signed by a trusted CA. The Node.js default is to trust the well-known CAs curated by Mozilla.
+
+Setting the server option `requestCert: true` tells the server to request the client certificate.
+
+The server option `rejectUnauthorized: false` allows us to handle any invalid certificate errors in client code. The `authorized` property on the socket of the incoming request will show if the client certificate was valid. The `authorizationError` property will give the reason if the certificate was not valid.
+
+### Client Certificate Authentication
+
+```js
+const { readFileSync } = require('fs')
+const { join } = require('path')
+const { createServer } = require('https')
+const { Client } = require('undici')
+
+const serverOptions = {
+  ca: [
+    readFileSync(join(__dirname, 'client-ca-crt.pem'), 'utf8')
+  ],
+  key: readFileSync(join(__dirname, 'server-key.pem'), 'utf8'),
+  cert: readFileSync(join(__dirname, 'server-crt.pem'), 'utf8'),
+  requestCert: true,
+  rejectUnauthorized: false
+}
+
+const server = createServer(serverOptions, (req, res) => {
+  // true if client cert is valid
+  if(req.client.authorized === true) {
+    console.log('valid')
+  } else {
+    console.error(req.client.authorizationError)
+  }
+  res.end()
+})
+
+server.listen(0, function () {
+  const tls = {
+    ca: [
+      readFileSync(join(__dirname, 'server-ca-crt.pem'), 'utf8')
+    ],
+    key: readFileSync(join(__dirname, 'client-key.pem'), 'utf8'),
+    cert: readFileSync(join(__dirname, 'client-crt.pem'), 'utf8'),
+    rejectUnauthorized: false,
+    servername: 'agent1'
+  }
+  const client = new Client(`https://localhost:${server.address().port}`, {
+    connect: tls
+  })
+
+  client.request({
+    path: '/',
+    method: 'GET'
+  }, (err, { body }) => {
+    body.on('data', (buf) => {})
+    body.on('end', () => {
+      client.close()
+      server.close()
+    })
+  })
+})
+```
diff --git a/docs/best-practices/mocking-request.md b/docs/best-practices/mocking-request.md
new file mode 100644
index 0000000..6954392
--- /dev/null
+++ b/docs/best-practices/mocking-request.md
@@ -0,0 +1,136 @@
+# Mocking Request
+
+Undici has its own mocking [utility](../api/MockAgent.md). It allow us to intercept undici HTTP requests and return mocked values instead. It can be useful for testing purposes.
+
+Example:
+
+```js
+// bank.mjs
+import { request } from 'undici'
+
+export async function bankTransfer(recipient, amount) {
+  const { body } = await request('http://localhost:3000/bank-transfer',
+    {
+      method: 'POST',
+      headers: {
+        'X-TOKEN-SECRET': 'SuperSecretToken',
+      },
+      body: JSON.stringify({
+        recipient,
+        amount
+      })
+    }
+  )
+  return await body.json()
+}
+```
+
+And this is what the test file looks like:
+
+```js
+// index.test.mjs
+import { strict as assert } from 'assert'
+import { MockAgent, setGlobalDispatcher, } from 'undici'
+import { bankTransfer } from './bank.mjs'
+
+const mockAgent = new MockAgent();
+
+setGlobalDispatcher(mockAgent);
+
+// Provide the base url to the request
+const mockPool = mockAgent.get('http://localhost:3000');
+
+// intercept the request
+mockPool.intercept({
+  path: '/bank-transfer',
+  method: 'POST',
+  headers: {
+    'X-TOKEN-SECRET': 'SuperSecretToken',
+  },
+  body: JSON.stringify({
+    recipient: '1234567890',
+    amount: '100'
+  })
+}).reply(200, {
+  message: 'transaction processed'
+})
+
+const success = await bankTransfer('1234567890', '100')
+
+assert.deepEqual(success, { message: 'transaction processed' })
+
+// if you dont want to check whether the body or the headers contain the same value
+// just remove it from interceptor
+mockPool.intercept({
+  path: '/bank-transfer',
+  method: 'POST',
+}).reply(400, {
+  message: 'bank account not found'
+})
+
+const badRequest = await bankTransfer('1234567890', '100')
+
+assert.deepEqual(badRequest, { message: 'bank account not found' })
+```
+
+Explore other MockAgent functionality [here](../api/MockAgent.md)
+
+## Debug Mock Value
+
+When the interceptor and the request options are not the same, undici will automatically make a real HTTP request. To prevent real requests from being made, use `mockAgent.disableNetConnect()`:
+
+```js
+const mockAgent = new MockAgent();
+
+setGlobalDispatcher(mockAgent);
+mockAgent.disableNetConnect()
+
+// Provide the base url to the request
+const mockPool = mockAgent.get('http://localhost:3000');
+
+mockPool.intercept({
+  path: '/bank-transfer',
+  method: 'POST',
+}).reply(200, {
+  message: 'transaction processed'
+})
+
+const badRequest = await bankTransfer('1234567890', '100')
+// Will throw an error
+// MockNotMatchedError: Mock dispatch not matched for path '/bank-transfer':
+// subsequent request to origin http://localhost:3000 was not allowed (net.connect disabled)
+```
+
+## Reply with data based on request
+
+If the mocked response needs to be dynamically derived from the request parameters, you can provide a function instead of an object to `reply`:
+
+```js
+mockPool.intercept({
+  path: '/bank-transfer',
+  method: 'POST',
+  headers: {
+    'X-TOKEN-SECRET': 'SuperSecretToken',
+  },
+  body: JSON.stringify({
+    recipient: '1234567890',
+    amount: '100'
+  })
+}).reply(200, (opts) => {
+  // do something with opts
+
+  return { message: 'transaction processed' }
+})
+```
+
+in this case opts will be
+
+```
+{
+  method: 'POST',
+  headers: { 'X-TOKEN-SECRET': 'SuperSecretToken' },
+  body: '{"recipient":"1234567890","amount":"100"}',
+  origin: 'http://localhost:3000',
+  path: '/bank-transfer'
+}
+```
diff --git a/docs/best-practices/proxy.md b/docs/best-practices/proxy.md
new file mode 100644
index 0000000..bf10295
--- /dev/null
+++ b/docs/best-practices/proxy.md
@@ -0,0 +1,127 @@
+# Connecting through a proxy
+
+Connecting through a proxy is possible by:
+
+- Using [AgentProxy](../api/ProxyAgent.md).
+- Configuring `Client` or `Pool` constructor.
+
+The proxy url should be passed to the `Client` or `Pool` constructor, while the upstream server url
+should be added to every request call in the `path`.
+For instance, if you need to send a request to the `/hello` route of your upstream server,
+the `path` should be `path: 'http://upstream.server:port/hello?foo=bar'`.
+
+If you proxy requires basic authentication, you can send it via the `proxy-authorization` header.
+
+### Connect without authentication
+
+```js
+import { Client } from 'undici'
+import { createServer } from 'http'
+import proxy from 'proxy'
+
+const server = await buildServer()
+const proxyServer = await buildProxy()
+
+const serverUrl = `http://localhost:${server.address().port}`
+const proxyUrl = `http://localhost:${proxyServer.address().port}`
+
+server.on('request', (req, res) => {
+  console.log(req.url) // '/hello?foo=bar'
+  res.setHeader('content-type', 'application/json')
+  res.end(JSON.stringify({ hello: 'world' }))
+})
+
+const client = new Client(proxyUrl)
+
+const response = await client.request({
+  method: 'GET',
+  path: serverUrl + '/hello?foo=bar'
+})
+
+response.body.setEncoding('utf8')
+let data = ''
+for await (const chunk of response.body) {
+  data += chunk
+}
+console.log(response.statusCode) // 200
+console.log(JSON.parse(data)) // { hello: 'world' }
+
+server.close()
+proxyServer.close()
+client.close()
+
+function buildServer () {
+  return new Promise((resolve, reject) => {
+    const server = createServer()
+    server.listen(0, () => resolve(server))
+  })
+}
+
+function buildProxy () {
+  return new Promise((resolve, reject) => {
+    const server = proxy(createServer())
+    server.listen(0, () => resolve(server))
+  })
+}
+```
+
+### Connect with authentication
+
+```js
+import { Client } from 'undici'
+import { createServer } from 'http'
+import proxy from 'proxy'
+
+const server = await buildServer()
+const proxyServer = await buildProxy()
+
+const serverUrl = `http://localhost:${server.address().port}`
+const proxyUrl = `http://localhost:${proxyServer.address().port}`
+
+proxyServer.authenticate = function (req, fn) {
+  fn(null, req.headers['proxy-authorization'] === `Basic ${Buffer.from('user:pass').toString('base64')}`)
+}
+
+server.on('request', (req, res) => {
+  console.log(req.url) // '/hello?foo=bar'
+  res.setHeader('content-type', 'application/json')
+  res.end(JSON.stringify({ hello: 'world' }))
+})
+
+const client = new Client(proxyUrl)
+
+const response = await client.request({
+  method: 'GET',
+  path: serverUrl + '/hello?foo=bar',
+  headers: {
+    'proxy-authorization': `Basic ${Buffer.from('user:pass').toString('base64')}`
+  }
+})
+
+response.body.setEncoding('utf8')
+let data = ''
+for await (const chunk of response.body) {
+  data += chunk
+}
+console.log(response.statusCode) // 200
+console.log(JSON.parse(data)) // { hello: 'world' }
+
+server.close()
+proxyServer.close()
+client.close()
+
+function buildServer () {
+  return new Promise((resolve, reject) => {
+    const server = createServer()
+    server.listen(0, () => resolve(server))
+  })
+}
+
+function buildProxy () {
+  return new Promise((resolve, reject) => {
+    const server = proxy(createServer())
+    server.listen(0, () => resolve(server))
+  })
+}
+```
+
diff --git a/docs/best-practices/writing-tests.md b/docs/best-practices/writing-tests.md
new file mode 100644
index 0000000..57549de
--- /dev/null
+++ b/docs/best-practices/writing-tests.md
@@ -0,0 +1,20 @@
+# Writing tests
+
+Undici is tuned for a production use case and its default will keep
+a socket open for a few seconds after an HTTP request is completed to
+remove the overhead of opening up a new socket. These settings that makes
+Undici shine in production are not a good fit for using Undici in automated
+tests, as it will result in longer execution times.
+
+The following are good defaults that will keep the socket open for only 10ms:
+
+```js
+import { request, setGlobalDispatcher, Agent } from 'undici'
+
+const agent = new Agent({
+  keepAliveTimeout: 10, // milliseconds
+  keepAliveMaxTimeout: 10 // milliseconds
+})
+
+setGlobalDispatcher(agent)
+```