asyncbridge

Call async functions from sync code. Call sync functions from async code. No drama.

The Problem

You have an async function but you're in sync code:

async def fetch_user(user_id: int) -> User:
    ...

# This doesn't work in sync code!
user = fetch_user(123)  # Returns coroutine, not User

Or you have sync code but need to call it from async without blocking:

def expensive_computation(data: bytes) -> Result:
    # CPU-intensive, blocks the event loop
    ...

The Solution

from asyncbridge import async_to_sync, sync_to_async

# Async → Sync
fetch_user_sync = async_to_sync(fetch_user)
user = fetch_user_sync(123)  # Just works!

# Sync → Async (runs in thread pool)
compute_async = sync_to_async(expensive_computation)
result = await compute_async(data)  # Doesn't block event loop

Installation

pip install asyncbridge

Features

• Zero dependencies - only stdlib
• Type-safe - full type hints, works with mypy
• Thread-safe - proper event loop handling
• Decorator support - use as decorator or wrapper

API

async_to_sync(func) → sync function

Converts an async function to sync. Handles event loop creation/reuse correctly.

from asyncbridge import async_to_sync

@async_to_sync
async def my_async_func():
    await asyncio.sleep(1)
    return "done"

result = my_async_func()  # Blocks until complete

sync_to_async(func) → async function

Runs sync function in thread pool executor to avoid blocking event loop.

from asyncbridge import sync_to_async

@sync_to_async
def blocking_io():
    time.sleep(1)
    return "done"

result = await blocking_io()  # Runs in thread, doesn't block loop

When to Use

Alternatives Comparison

License

MIT