anil.recoil.org
mqtte#
An MQTT protocol library for OCaml with an Eio-based client.
Features#
- MQTT v3.1.1 and v5.0 support - Full protocol implementations for both versions
- Effects-based I/O - Built on Eio for modern OCaml 5+ concurrency
- QoS levels - Support for all three quality of service levels (0, 1, 2)
- Topic wildcards - Full support for single-level (+) and multi-level (#) wildcards
- Connection pooling - Integration with conpool for efficient connection management
- TLS support - Secure connections via tls-eio
- Command-line tools - Cmdliner integration for easy CLI application building
Installation#
opam install mqtte
Usage#
Publisher Example#
open Mqtte_eio.Client
let () =
Eio_main.run @@ fun env ->
Eio.Switch.run @@ fun sw ->
let config = default_config ~client_id:"my-publisher" () in
let client = connect
~sw
~net:(Eio.Stdenv.net env)
~clock:(Eio.Stdenv.clock env)
~config
~host:"127.0.0.1"
~port:1883
()
in
publish ~qos:`At_least_once ~topic:"sensors/temperature" "22.5" client;
disconnect client
Subscriber Example#
open Mqtte_eio.Client
let () =
Eio_main.run @@ fun env ->
Eio.Switch.run @@ fun sw ->
let config = default_config ~client_id:"my-subscriber" () in
let on_message msg =
Printf.printf "Received [%s]: %s\n" msg.topic msg.payload
in
let client = connect
~sw
~net:(Eio.Stdenv.net env)
~clock:(Eio.Stdenv.clock env)
~on_message
~config
~host:"127.0.0.1"
~port:1883
()
in
subscribe ~qos:`At_least_once ["sensors/#"] client;
Eio.Time.sleep (Eio.Stdenv.clock env) 60.0;
disconnect client
Library Structure#
- mqtte - Core protocol types and codecs (no I/O dependencies)
- mqtte.eio - Full client library with Eio-based transport
Documentation#
API documentation is available at: https://tangled.org/@anil.recoil.org/ocaml-mqtte
License#
ISC License. See LICENSE.md for details.