Klaus Demo ~jonashaag/bjoern / 1.4.1

Tree @1.4.1 (Download .tar.gz)

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

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



Arch Linux
pacman -S libev
apt-get install libev-dev
Fedora, CentOS
yum install libev-devel
Mac OS X (using homebrew)
brew install libev
Your Contribution Here
Fork me and send a pull request


For most users, the easiest way to install bjoern is using pip. Make sure libev is installed and then:

pip install bjoern


# Bind to TCP host/port pair:
bjoern.run(wsgi_application, host, port)

# TCP host/port pair, enabling SO_REUSEPORT if available.
bjoern.run(wsgi_application, host, port, reuseport=True)

# Bind to Unix socket:
bjoern.run(wsgi_application, 'unix:/path/to/socket')

# Bind to abstract Unix socket: (Linux only)
bjoern.run(wsgi_application, '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)

System Message: INFO/1 (<string>, line 72); backlink

Duplicate implicit target name: "libev".