cfloop

An asyncio event loop on macOS’s CFRunLoop, so coroutines, Carbon events, and main-queue delegates share the main thread.

import asyncio, cfloop

async def main():
    await asyncio.sleep(1)  # Carbon events and main-queue callbacks keep dispatching meanwhile

# the asyncio.run twin, which must own the main thread
cfloop.run(main())
# or compose it yourself (also asyncio.Runner)
asyncio.run(main(), loop_factory=cfloop.new_event_loop)

That is the whole API. The loop is a stock asyncio.SelectorEventLoop whose selector waits inside a Carbon event pump instead of a bare kqueue. So whenever asyncio is idle, Carbon events dispatch (hotkeys included), CFRunLoop timers and sources fire, and the main dispatch queue drains. Everything asyncio provides is inherited, not reimplemented: tasks, subprocesses, signal handling, debug mode’s slow-callback warnings. macOS only, Python 3.12+.

The substrate is a small pyo3 module:

• pump: manual ReceiveNextEvent dispatch, the part macOS won’t do for you (DEV.md has the probe history)
• FdWatch: a CFSocket source that wakes the pump when a registered file descriptor becomes ready
• post_wake: post a no-op Carbon event from any thread, to break the pump out of its wait
• call_later: a CFRunLoopTimer that calls back into Python
• run_app/quit_app: for callers who want Carbon’s own RunApplicationEventLoop to own the thread instead

Development

pip install -e .[dev]
maturin develop && pytest -q

Build

ship-rs-build

Release

maturin develop && pytest -q
ship-release

ship-release tags the Cargo version, leaves wheel publication to GitHub Actions, then bumps the project.