Open Source Messaging Projects
Messaging technology enables people, applications, and devices to exchange text, media, alerts, and other information. It helps coordinate conversations across networks, deliver timely notifications, and connect services that would otherwise operate separately. Messaging systems may prioritize private person-to-person communication, group collaboration, automated updates, or communication between software components.
Open source tools in this area include chat clients and servers, notification services, messaging libraries, bots, and bridges that connect different platforms. When choosing one, consider its security and privacy model, supported protocols, license, maintenance activity, hosting requirements, and compatibility with your existing systems. These tools are useful to individuals, communities, organizations, and developers building communication features or managing messages across multiple services.
3 repositories · updated October 3, 2026

simplex-chat: Private Messaging Without User Identifiers
SimpleX Chat is an end-to-end encrypted messaging platform designed to work without persistent user identifiers. It offers mobile and desktop apps, plus a terminal client, for people who want to reduce exposure of their contacts and messaging metadata.

Notify: A Robust Notification Service in ASP.NET Core
Notify is an advanced notification system built with ASP.NET Core and MongoDB, designed for seamless and efficient sending of synchronous and asynchronous messages. It ensures reliable delivery through integrated checks and supports various notification types like email and SMS, with multi-provider flexibility.

heyoo: An Open-Source Python Wrapper for WhatsApp Cloud API
heyoo is an open-source Python wrapper designed to simplify interactions with the WhatsApp Cloud API. This library enables developers to easily send various message types, including text, media, location, and interactive buttons. It also provides robust features for handling incoming messages via webhooks, making it a comprehensive solution for WhatsApp automation.