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Beast is a C++ header-only library serving as a foundation for writing interoperable networking libraries by providing low-level HTTP/1, WebSocket, and networking protocol vocabulary types and algorithms using the consistent asynchronous model of Boost.Asio.

This library is designed for:

This library is not a client or server, but it can be used to build those things. Many examples are provided, including clients and servers, which may be used as a starting point for writing your own program.


Beast empowers users to create their own libraries, clients, and servers using HTTP/1 and WebSocket. Code will be easier and faster to implement, understand, and maintain, because Beast takes care of the low-level protocol details. The HTTP and WebSocket protocols drive most of the World Wide Web. Every web browser implements these protocols to load webpages and to enable client side programs (often written in JavaScript) to communicate interactively. C++ benefits greatly from having a standardized implementation of these protocols.

[Important] Important

This library is for programmers familiar with Boost.Asio. Users who wish to use asynchronous interfaces should already know how to create concurrent network programs using callbacks or coroutines.

Beast requires:

  • C++11: Robust support for most language features.
  • Boost: Beast only works with Boost, not stand-alone Asio
  • OpenSSL: Optional, for using TLS/Secure sockets.

Supported compilers: msvc-14+, gcc 4.8+, clang 3.6+

Sources are header-only. To link a program using Beast successfully, add the Boost.System library to your build scripts. If you use coroutines you'll also need the Boost.Coroutine library. Please visit the Boost documentation for instructions on how to do this for your particular build system.

To report bugs or get help using Beast, GitHub issues are preferred. Please visit to ask a question, report a defect, or request a feature. If you prefer to keep your issue or question confidential please email the author at


Boost.Asio is the inspiration behind which all of the interfaces and implementation strategies are built. Some parts of the documentation are written to closely resemble the wording and presentation of Boost.Asio documentation. Credit goes to Christopher Kohlhoff for his wonderful Asio library and the ideas in C++ Extensions for Networking which power Beast.

Beast would not be possible without the support of Ripple during the library's early development, or the ideas, time and patience contributed by David Schwartz, Edward Hennis, Howard Hinnant, Miguel Portilla, Nik Bougalis, Scott Determan and Scott Schurr. Many thanks to Agustín Bergé, Glen Fernandes, and Peter Dimov for tirelessly answering questions on Cpplang-Slack.

Thanks to Damian Jarek for his generous participation and source code contributions.