uvloop is a fast, drop-in replacement of the built-in asyncio event loop. uvloop is implemented in Cython and uses libuv under the hood.

The project documentation can be found here. Please also check out the wiki.

uvloop makes asyncio 2-4x faster.

The above chart shows the performance of an echo server with different message sizes. The sockets benchmark uses loop.sock_recv() and loop.sock_sendall() methods; the streams benchmark uses asyncio high-level streams, created by the asyncio.start_server() function; and the protocol benchmark uses loop.create_server() with a simple echo protocol. Read more about uvloop performance.

uvloop requires Python 3.5 or greater and is available on PyPI. Use pip to install it:

$ pip install uvloop

To make asyncio use uvloop, you can install the uvloop event loop policy:

import asyncio
import uvloop

asyncio.set_event_loop_policy(uvloop.EventLoopPolicy())

To build uvloop, you'll need Python 3.5 or greater:

1. Clone the repository:

   $ git clone --recursive git@github.com:MagicStack/uvloop.git
   $ cd uvloop

2. Create a virtual environment and activate it, for example:

   $ python3.7 -m venv uvloop-dev
   $ source uvloop-dev/bin/activate

3. Install development dependencies:

   $ pip install -r requirements.dev.txt

4. Build and run tests:

   $ make && make test

uvloop is dual-licensed under MIT and Apache 2.0 licenses.