ØMQ bindings for Node.js. The goals of this library are:
- Semantically similar to the native ØMQ library, while sticking to JavaScript idioms.
- Use modern JavaScript and Node.js features such as
async/awaitand async iterators. - High performance.
- Fully usable with TypeScript (3+).
- ZeroMQ.js API reference.
- ZeroMQ project documentation.
- Note: The Node.js examples on zeromq.org do not yet reflect the new API, but the Guide in particular is still a good introduction to ZeroMQ for new users.
Install ZeroMQ.js with prebuilt binaries:
npm install zeromqRequirements for using prebuilt binaries:
- Node.js 10.2+ or Electron 3+ (requires a N-API version 3+)
The following platforms have a prebuilt binary available:
- Linux on x86-64 with libstdc++.so.6.0.21+ (glibc++ 3.4.21+), for example:
- Debian 9+ (Stretch or later)
- Ubuntu 16.04+ (Xenial or later)
- CentOS 8+
- Linux on x86-64 with musl, for example:
- Alpine 3.3+
- MacOS 10.9+ on x86-64
- Windows on x86/x86-64
If a prebuilt binary is not available for your platform, installing will attempt to start a build from source.
If a prebuilt binary is unavailable or if you want to pass certain options during build, you can build this package from source.
Make sure you have the following installed before attempting to build from source:
- Node.js 10+ or Electron 3+
- A working C++17 compiler toolchain with make
- Python 3 with Node 12.13+ (or legacy Python 2.7)
- CMake 2.8+
- curl
To install from source, specify build_from_source=true in a .npmrc file
build_from_source=true
When building from source, you can also specify additional build options in a
.npmrc file in your project:
👉🏻 Options
By default libzmq is built with support for Draft patterns (e.g.
server-client, radio-dish, scatter-gather). If you want to build libzmq
without support for Draft, you can specify the following in .npmrc:
zmq_draft=falseIf you want to send/receive on the socket immediately, you can specify the
following in .npmrc:
zmq_no_sync_resolve="true"If you want to link against a shared ZeroMQ library installed on your system,
you can build skip downloading libzmq and link with the installed library
instead by specifying the following in .npmrc:
zmq_shared=trueYou can specify an alternative version or Git revision of libzmq to build
against by specifying the following in .npmrc:
zmq_version="4.3.5"If you want to build libzmq with debug symbols, you can specify the following
in .npmrc:
zmq_build_type="Debug"If you want to cross-compile for a different architecture, you can specify the
following in .npmrc:
arch="arm64"
target_arch="arm64"If you want to specify the MacOS deployment target, you can specify the
following in .npmrc:
macos_deployment_target="10.15"Note: These examples assume the reader is familiar with ZeroMQ. If you are new to ZeroMQ, please start with the ZeroMQ documentation.
More examples can be found in the examples directory.
This example demonstrates how a producer pushes information onto a socket and how a worker pulls information from the socket.
Creates a producer to push information onto a socket.
const zmq = require("zeromq")
async function run() {
const sock = new zmq.Push()
await sock.bind("tcp://127.0.0.1:3000")
console.log("Producer bound to port 3000")
while (true) {
await sock.send("some work")
await new Promise(resolve => {
setTimeout(resolve, 500)
})
}
}
run()Creates a worker to pull information from the socket.
const zmq = require("zeromq")
async function run() {
const sock = new zmq.Pull()
sock.connect("tcp://127.0.0.1:3000")
console.log("Worker connected to port 3000")
for await (const [msg] of sock) {
console.log("work: %s", msg.toString())
}
}
run()This example demonstrates using zeromq in a classic Pub/Sub,
Publisher/Subscriber, application.
Create the publisher which sends messages.
const zmq = require("zeromq")
async function run() {
const sock = new zmq.Publisher()
await sock.bind("tcp://127.0.0.1:3000")
console.log("Publisher bound to port 3000")
while (true) {
console.log("sending a multipart message envelope")
await sock.send(["kitty cats", "meow!"])
await new Promise(resolve => {
setTimeout(resolve, 500)
})
}
}
run()Create a subscriber to connect to a publisher's port to receive messages.
const zmq = require("zeromq")
async function run() {
const sock = new zmq.Subscriber()
sock.connect("tcp://127.0.0.1:3000")
sock.subscribe("kitty cats")
console.log("Subscriber connected to port 3000")
for await (const [topic, msg] of sock) {
console.log(
"received a message related to:",
topic,
"containing message:",
msg,
)
}
}
run()This example illustrates a request from a client and a reply from a server.
const zmq = require("zeromq")
async function run() {
const sock = new zmq.Request()
sock.connect("tcp://127.0.0.1:3000")
console.log("Producer bound to port 3000")
await sock.send("4")
const [result] = await sock.receive()
console.log(result)
}
run()const zmq = require("zeromq")
async function run() {
const sock = new zmq.Reply()
await sock.bind("tcp://127.0.0.1:3000")
for await (const [msg] of sock) {
await sock.send(2 * parseInt(msg, 10))
}
}
run()This library provides typings for TypeScript version 3.0.x and later.
Requirements
- For TypeScript version >= 3:
- For TypeScript version < 3.6:
- either set
compilerOptions.targettoesnextor later (e.g.es2018) - or add the following, or similar, libraries to
compilerOptions.lib(and include their corresponding polyfills if needed):es2015,ESNext.AsyncIterable
- either set
Example Usage
import {Request} from "zeromq"
// or as namespace
import * as zmq from "zeromq"
const reqSock = new Request()
//...
const repSock = new zmq.Reply()More advanced examples can be found in the examples directory of this repository.
Or you can browse the API reference documentation to see all socket types, methods & options as well as more detailed information about how to apply them.
The next generation version of the library features a compatibility layer for ZeroMQ.js versions 4 and 5. This is recommended for users upgrading from previous versions.
Example:
const zmq = require("zeromq/v5-compat")
const pub = zmq.socket("pub")
const sub = zmq.socket("sub")
pub.bind("tcp://*:3456", err => {
if (err) throw err
sub.connect("tcp://127.0.0.1:3456")
pub.send("message")
sub.on("message", msg => {
// Handle received message...
})
})If you are interested in making contributions to this project, please read the following sections.
In order to develop and test the library, you'll need the tools required to build from source (see above).
Additionally, having clang-format is strongly recommended.
Socket and context options can be set at runtime, even if they are not implemented by this library. By design, this requires no recompilation if the built version of ZeroMQ has support for them. This allows library users to test and use options that have been introduced in recent versions of ZeroMQ without having to modify this library. Of course we'd love to include support for new options in an idiomatic way.
Options can be set as follows:
const {Dealer} = require("zeromq")
/* This defines an accessor named 'sendHighWaterMark', which corresponds to
the constant ZMQ_SNDHWM, which is defined as '23' in zmq.h. The option takes
integers. The accessor name has been converted to idiomatic JavaScript.
Of course, this particular option already exists in this library. */
class MyDealer extends Dealer {
get sendHighWaterMark(): number {
return this.getInt32Option(23)
}
set sendHighWaterMark(value: number) {
this.setInt32Option(23, value)
}
}
const sock = new MyDealer({sendHighWaterMark: 456})When submitting pull requests for new socket/context options, please consider the following:
- The option is documented in the TypeScript interface.
- The option is only added to relevant socket types, and if the ZMQ_ constant has a prefix indicating which type it applies to, it is stripped from the name as it is exposed in JavaScript.
- The name as exposed in this library is idiomatic for JavaScript, spelling out
any abbreviations and using proper
camelCasenaming conventions. - The option is a value that can be set on a socket, and you don't think it should actually be a method.
The test suite can be run with:
npm install
npm run build
npm run testThe test suite will validate and fix the coding style, run all unit tests and verify the validity of the included TypeScript type definitions.
Some tests are not enabled by default:
- API Compatibility tests from ZeroMQ 5.x have been disabled by default. You can
include the tests with
INCLUDE_COMPAT_TESTS=1 npm run test - Some transports are not reliable on some older versions of ZeroMQ, the relevant tests will be skipped for those versions automatically.
To publish a new version, run:
npm version <new version>
git push && git push --tagsWait for continuous integration to finish. Prebuilds will be generated for all
supported platforms and attached to a Github release. Documentation is
automatically generated and committed to gh-pages. Finally, a new NPM package
version will be automatically released.
Version 6+ is a complete rewrite of previous versions of ZeroMQ.js in order to
be more reliable, correct, and usable in modern JavaScript & TypeScript code as
first outlined in this issue.
Previous versions of ZeroMQ.js were based on zmq and a fork that included
prebuilt binaries.
See detailed changes in the CHANGELOG.