emitix

emitix is a small event bus for Python: no dependencies, fully typed, and happy in both synchronous and asynchronous codebases. It’s on PyPI as emitix.

Why

Most Python projects eventually need a way to decouple “something happened” from “here’s what to do about it.” emitix keeps that simple - a single import, a decorator, and you’re publishing and subscribing to events.

A minimal example

import emitix

@emitix.on("user.created")
def send_welcome_email(user):
    print(f"Welcome, {user}!")

emitix.emit("user.created", "Ada")

What it does

• Passes arbitrary arguments from emit straight through to handlers
• Wildcard pattern matching for subscriptions
• One-shot handlers via once()
• Priority-based handler ordering
• Async handlers through emit_async()
• Unsubscribe with off()
• Thread-safe by design

await bus.emit_async("order.placed", order)

@emitix.on("order.placed", priority=10)   # runs first
def reserve_stock(order): ...

@emitix.on("order.*")                       # wildcard
def audit(event, *args): ...

Install

pip install emitix

Licensed MIT. Source on GitHub.