asyncbridge 1.0.0

Simple, reliable async/sync conversion for Python. Call async from sync and vice versa.

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

Situation	Solution
Calling async library from sync script	async_to_sync
Using async ORM in sync framework	async_to_sync
CPU-bound work in async server	sync_to_async
Blocking I/O in async code	sync_to_async

Alternatives Comparison

Package	Deps	Framework-agnostic	Maintained
asyncbridge	0	✅	✅
asgiref	1	Django-focused	✅
nest-asyncio	0	Different purpose	✅

License

MIT