This repo is obsolete. The main point of event based IO is less memory for concurrent connections, and pay less time in CPU context switching, thus leading to higher performance benchmarks. But in real the heavy computation remains in ORMs like active record, the saved CPU time is insignificant while the implementation requires complex tweaks.

ニャラ is Not Yet Another Ruby Async web framework and server.

Build Status

  • Very few runtime dependencies, faster than any web framework on rack.
  • Nonblock but no callback hell, very low CPU and memory usage.
  • Simple usage, and you don't have to make everything non-block.
  • Prefork production server, with signal-based management which enables graceful restart.
  • Route actions with scanf-like DSL.
  • Simple request format matcher.
  • Optimized render and layout helpers, easy to stream the view.

Getting started


  • System: BSD/Linux/Mac OS X
  • Interpreter: Ruby 2.0.0 or higher
  • Compiler: GCC or Clang


gem ins --pre nyara

Edit a file, name it nyahaha.rb for example

require 'nyara'
get '/' do
  send_string 'hello world'

And start server

ruby nyahaha.rb




  • Not based on rack.
  • Not compatible with eventmachine. It won't work if you add gems like em-synchrony.
  • Not yet another ruby async framework, some features in a common async IO framework are not implemented.
  • Doesn't and won't work on JRuby or lower versions of Ruby.
  • Doesn't and won't work on Windows.


BSD 3-Clause, see copying