This is a very young project. It’s used and validated mainly by the Python Ethereum client (Trinity) Lahja is alpha state software. Expect bugs.

Lahja is a generic multi process event bus implementation written in Python 3.6+ that enables lightweight inter-process communication, based on non-blocking asyncio.


Lahja is tailored around one primary use case: Enabling event-based communication between different processes in moder Python applications using non-blocking asyncio.


  • Non-blocking APIs based on asyncio
  • Broadcast events within a single process or across multiple processes.
  • Multiple APIs to consume events that adapt to different use cases and styles
  • lightweight and simple (e.g. no IPC pipe management etc)
  • Easy event routing (e.g. route specific events to specific processes or process groups)

Further reading

Here are a couple more useful links to check out.