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 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())

Alternatively, you can create an instance of the loop manually, using:

loop = uvloop.new_event_loop()
asyncio.set_event_loop(loop)

To build uvloop, you'll need Cython and Python 3.5. The best way is to create a virtual env, so that you'll have cython and python commands pointing to the correct tools.

1. git clone --recursive git@github.com:MagicStack/uvloop.git
2. cd uvloop
3. make
4. make test

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