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A screamingly fast Python WSGI server written in C.
C Python Makefile Other
Latest commit 25adb4c @jonashaag Switch to setuptools


bjoern: Fast And Ultra-Lightweight HTTP/1.1 WSGI Server

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A screamingly fast, ultra-lightweight WSGI server for CPython, written in C using Marc Lehmann's high performance libev event loop and Ryan Dahl's http-parser.

Why It's Cool

bjoern is the fastest, smallest and most lightweight WSGI server out there, featuring

  • ~ 1000 lines of C code
  • Memory footprint ~ 600KB
  • Single-threaded and without coroutines or other crap
  • Can bind to TCP host:port addresses and Unix sockets (thanks @k3d3!)
  • Full persistent connection ("keep-alive") support in both HTTP/1.0 and 1.1, including support for HTTP/1.1 chunked responses


pip install bjoern. See wiki for details.


# Bind to TCP host/port pair:, host, port)

# TCP host/port pair, enabling SO_REUSEPORT if available., host, port, reuse_port=True)

# Bind to Unix socket:, 'unix:/path/to/socket')

# Bind to abstract Unix socket: (Linux only), 'unix:@socket_name')

Alternatively, the mainloop can be run separately:

bjoern.listen(wsgi_application, host, port)

You can also simply pass a Python socket(-like) object. Note that you are responsible for initializing and cleaning up the socket in that case.

bjoern.server_run(socket_object, wsgi_application)
bjoern.server_run(filedescriptor_as_integer, wsgi_application)
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