This example will not work in browsers or other platforms that don't allow passing an object.

import { WebSocket, ProxyAgent } from 'undici'

const proxyAgent = new ProxyAgent('my.proxy.server')

If you do not need a custom Dispatcher, it's recommended to use the following pattern:

import { WebSocket } from 'undici'

const ws = new WebSocket('wss://echo.websocket.events', ['echo', 'chat'])

This example will not work in browsers or other platforms that don't allow passing an object.

import { Agent } from 'undici'

const agent = new Agent({ allowH2: true })

if (entry.port && entry.port !== port) {

continue // Skip if ports don't match.

}

// Don't proxy if the hostname is equal with the no_proxy host.

if (hostname === entry.hostname) {

return false

}

// Don't proxy if the hostname is the subdomain of the no_proxy host.

// Reference - https://github.com/denoland/deno/blob/6fbce91e40cc07fc6da74068e5cc56fdd40f7b4c/ext/fetch/proxy.rs#L485

if (hostname.slice(-(entry.hostname.length + 1)) === `.${entry.hostname}`) {

return false

}

}

}

const parsed = entry.match(/^(.+):(\d+)$/)

noProxyEntries.push({

// strip leading dot or asterisk with dot

hostname: (parsed ? parsed[1] : entry).replace(/^\*?\./, '').toLowerCase(),

port: parsed ? Number.parseInt(parsed[2], 10) : 0

})

}

// Not modified, re-use the cached value

// https://www.rfc-editor.org/rfc/rfc9111.html#name-handling-304-not-modified

if (statusCode === 304) {

const handle304 = (cachedValue) => {

if (!cachedValue) {

// Do not create a new cache entry, as a 304 won't have a body - so cannot be cached.

return downstreamOnHeaders()

}

// Re-use the cached value: statuscode, statusmessage, headers and body

value.statusCode = cachedValue.statusCode

value.statusMessage = cachedValue.statusMessage

value.etag = cachedValue.etag

value.headers = { ...cachedValue.headers, ...strippedHeaders }

downstreamOnHeaders()

this.#writeStream = this.#store.createWriteStream(this.#cacheKey, value)

if (!this.#writeStream || !cachedValue?.body) {

return

}

if (typeof cachedValue.body.values === 'function') {

const bodyIterator = cachedValue.body.values()

const streamCachedBody = () => {

for (const chunk of bodyIterator) {

const full = this.#writeStream.write(chunk) === false

this.#handler.onResponseData?.(controller, chunk)

// when stream is full stop writing until we get a 'drain' event

if (full) {

break

}

}

}

this.#writeStream

.on('error', function () {

handler.#writeStream = undefined

handler.#store.delete(handler.#cacheKey)

})

.on('drain', () => {

streamCachedBody()

})

.on('close', function () {

if (handler.#writeStream === this) {

handler.#writeStream = undefined

}

})

streamCachedBody()

} else if (typeof cachedValue.body.on === 'function') {

// Readable stream body (e.g. from async/remote cache stores)

cachedValue.body

.on('data', (chunk) => {

this.#writeStream.write(chunk)

this.#handler.onResponseData?.(controller, chunk)

})

.on('end', () => {

this.#writeStream.end()

})

.on('error', () => {

this.#writeStream = undefined

this.#store.delete(this.#cacheKey)

})

this.#writeStream

.on('error', function () {

handler.#writeStream = undefined

handler.#store.delete(handler.#cacheKey)

})

.on('close', function () {

if (handler.#writeStream === this) {

handler.#writeStream = undefined

}

})

}

}

/**

const result = this.#store.get(this.#cacheKey)

if (result && typeof result.then === 'function') {

result.then(handle304)

} else {

handle304(result)

}

} else {

if (typeof resHeaders.etag === 'string' && isEtagUsable(resHeaders.etag)) {

value.etag = resHeaders.etag

// Start background revalidation (fire-and-forget)

queueMicrotask(() => {

const headers = {

...opts.headers,

'if-modified-since': new Date(result.cachedAt).toUTCString()

}

}

if (result.vary) {

for (const key in result.vary) {

if (result.vary[key] != null) {

headers[key] = result.vary[key]

}

}

}

withinStaleIfErrorThreshold = now < (result.staleAt + (staleIfErrorExpiry * 1000))

}

const headers = {

...opts.headers,

'if-modified-since': new Date(result.cachedAt).toUTCString()

}

}

if (result.vary) {

for (const key in result.vary) {

if (result.vary[key] != null) {

headers[key] = result.vary[key]

}

}

}

// Convert to lowercase Set for case-insensitive header exclusion from deduplication key

const excludeHeaderNamesSet = new Set(excludeHeaderNames.map(name => name.toLowerCase()))

/**

return dispatch => {

return (opts, handler) => {

if (!opts.origin || methods.includes(opts.method) === false) {

return dispatch(opts, handler)

}

> undici@7.22.0 build:wasm

> node build/wasm.js --docker

> docker run --rm --platform=linux/x86_64 --user 1001:1001 --mount type=bind,source=/home/runner/work/node/node/deps/undici/src/lib/llhttp,target=/home/node/build/lib/llhttp --mount type=bind,source=/home/runner/work/node/node/deps/undici/src/build,target=/home/node/build/build --mount type=bind,source=/home/runner/work/node/node/deps/undici/src/deps,target=/home/node/build/deps -t ghcr.io/nodejs/wasm-builder@sha256:975f391d907e42a75b8c72eb77c782181e941608687d4d8694c3e9df415a0970 node build/wasm.js

reject(error)

},

onRequestUpgrade (_controller, status, headers, socket) {

// We need to support 200 for websocket over h2 as per RFC-8441

// Absence of session means H1

if ((socket.session != null && status !== 200) || (socket.session == null && status !== 101)) {

return false

}

const headersList = new HeadersList()

for (const [name, value] of Object.entries(headers)) {

if (value == null) {

continue

}

const headerName = name.toLowerCase()

if (Array.isArray(value)) {

for (const entry of value) {

headersList.append(headerName, String(entry), true)

}

} else {

headersList.append(headerName, String(value), true)

}

}

resolve({

status,

statusText: STATUS_CODES[status],

headersList,

socket

})

return true

},

onUpgrade (status, rawHeaders, socket) {

// We need to support 200 for websocket over h2 as per RFC-8441

// Absence of session means H1

function includesCredentials (url) {

// A URL includes credentials if its username or password is not the empty string.

return !!(url.username || url.password)