Messaging GitHub Repositories (2026) · Open Source Tools

An observable microservice bus library for .NET, that wraps the underlying message transports in simple Rx based interfaces.

Framework for building Event-Driven Microservices

Parallel Apache Kafka client wrapper with per message ACK, client side queueing, a simpler consumer/producer API with key concurrency and extendable non-blocking IO processing.

Full-feature WAMP v2 router and client written in Go

SmallRye Reactive Messaging

The official .NET client library for Apache Pulsar

The cloud-native configuration driven runtime that helps developers implement composite microservices.

Gem that allows communication between the models.

simple but convenient CLI-based Matrix client app for sending and receiving (in Rust)

Email, SMS & phone-call infrastructure for AI agents — send and receive real email and text messages, and place agent-driven outbound voice calls, all programmatically

MQTT on Pulsar implemented using Pulsar Protocol Handler

Ruby client for NATS, the cloud native messaging system.

IoT Platform Framework

Keep passwords and other sensitive information out of your chat logs and inboxes.

CometChat docs search + implementation bundles: add chat, voice, video & moderation to your app through your AI coding agent.

AMQP on Pulsar protocol handler

Open Source Messaging Framework. Queues, Channels, Events, Transactions, Distributed Cache

An IRC Client for Android

Vonage Server SDK for Java. API support for SMS, Messages, Voice, Text-to-Speech, Numbers, Verify (2FA), Video and more.

An open-source team messenger for groups of up to 30, with spaces, threads, files and voice notes. Built with Next.js and PostgreSQL, deployed on Tofu.