Opifex

Opifex aims to provide a MQTT server and MQTT client in Typescript to be used with NodeJS, Deno or Bun. It has no third-party dependencies, it only relies on built-in modules.

Compatibility

The following MQTT versions are supported:

| | MQTT 3.1 (v3) | MQTT 3.1.1 (v4) | MQTT 5.0 (v5) | | -------------- | ------------- | --------------- | --------------- | | Packet/encoder | ✅ | ✅ | ✅ | | Client | ✅ | ✅ | ✅ 1 | | Server | ❌ | ✅ | ✅ |

1 The client API fully supports MQTTv5, the CLI only supports a subset

Version 5 support includes:

• Client Topic Alias ✅
• Server Topic Alias ✅
• Subscription Identifiers ✅
• Subscription options (NoLocal, RetainAsPublished, RetainHandling) ✅
• Message expiry interval ✅
• Will delay ✅
• Assigned Client Identifier ✅
• Client receive maximum ✅
• Server receive maximum ✅
• Shared Subscriptions ✅

Transports

The following transports are currently supported:

• plain TCP ✅
• TLS ✅
• WebSockets ✅ 2

2 Deno + Browser only, NodeJS has no native websocket support.

You can add your own transports.

Persistence

Opifex offers pluggable persistence, but one can provide its own persistence. (see Architecture)

The following types are currently provided:

| | Plugable | Memory | Sqlite | | ------ | -------- | ------ | ------ | | Client | ✅ | ✅ | ❌ | | Server | ✅ | ✅ | ✅ |

Usage

The easiest way to use this project is to just use the demo server (demoServer) and/or the demo client (mqtt).

• NodeJS/Bun
• Deno

If you want to change the behaviour of the server and/or the client beyond what can be done with CLI options then the next step is to clone the demo server and/or the client scripts and modify them to your liking.

If you want to port the platform independent client and server libs to other types of transports (e.g. Unix sockets) then it's recommended to clone and modify the platform specific code in /node , /deno or /web as well.

If you want to port the platform independent client and server libs to another platform then the platform specific code in /node or /deno might serve as inspiration.

Bun (as of version 1.2) and Deno are both capable of running the NodeJS version, but for historic reasons /deno still exists.

Example

A simple server example:

import { TcpServer } from "@seriousme/opifex/tcpServer";

const server = new TcpServer({ port: 1883 }, {
  // just an example of how to configure the server
  configuration: {
    context: { maximumConnectPacketSize: 3000 },
  },
});
server.start();
console.log(
  `MQTT server running on port: ${server.port}, address: ${server.address}`,
);

More elaborate examples including client and server, TLS, Websockets and sqlite can be found in the examples folder.

Architecture

1. The basis of Opifex is the MQTT packet module (mqttPacket/mod.ts) which contains all the logic to encode and decode packets.

2. On top of mqttPacket sits the MQTT connection module (mqttConn/mod.ts) that reads packets from a Readable stream and writes them to Writable stream. It will take care of incomplete and/or malformed packets. mqttConn provides an async iterable that can be awaited for new packets.

3. On top of mqttConn live the MQTT server (server/mod.ts) and MQTT client (client/mod.ts) that take care of the MQTT protocol handling like requiring an authentication to be successful before another type of packet will be accepted. Both follow a similar model of implementation where for each packet that is received a handler is invoked which then triggers the next step. Server and client are totally independent of the technical implementation of the connection and only need a socketConn (socket) to be able to work.

4. As the server needs to be able to serve multiple clients at the same time, it maintains a context (server/context.ts) per client to keep track of its state and associated timers.

5. Persistence of data is handled by a pluggable persistence module (persistence) which currently offers single process persistence which you can replace by something more scalable (e.g. redis based clusters etc) This is backed by two storage providers:

   • memory
   • sqlite, based on node:sqlite

   but can be extended with other database backend persistence supported by third-party modules.

6. Server behavior can be customized by passing a ConfigurationInput object via MqttServerOptions.configuration, see the example above.

7. The demo server listens to a platform specific socket and runs the serve() method from the server module on the platform independent streams of every connection.

8. The demo client opens a platform specific socket and passes the resulting platform independent streams to the client module.

Exports

| Export | Description | | ----------------------------- | ------------------------------------------------------------ | | @seriousme/opifex/tcpClient | Exports a MQTT over TCP/TLS client | | @seriousme/opifex/tcpServer | Exports a MQTT over TCP server | | @seriousme/opifex/tlsServer | Exports a MQTT over TLS server | | @seriousme/opifex/wsClient | Exports a MQTT over Websocket client (deno and browser only) | | @seriousme/opifex/wsServer | Exports a MQTT over Websocket server (deno only) | | @seriousme/opifex/server | Exports a transport agnostic MQTT server | | @seriousme/opifex/client | Exports a transport agnostic MQTT client | | @seriousme/opifex/persistence | Exports a Typescript interface for storage persistence | | @seriousme/opifex/mqttConn | Exports MQTT connection handling | | @seriousme/opifex/mqttPacket | Exports MQTT packet handling | | @seriousme/opifex/utils | Exports various utilities |

API docs

The latest API documentation can be found at: https://jsr.io/@seriousme/opifex@latest/doc

Naming

Some MQTT servers have names like:

• Mosquitto
• Mosca
• Aedes

So to stay with the theme: Opifex

License

Licensed under MIT