3.4.3. Advanced features : Scripting

HAProxy can be built with support for the Lua embedded language, which opens a
wide area of new possibilities related to complex manipulation of requests or
responses, routing decisions, statistics processing and so on. Using Lua it is
even possible to establish parallel connections to other servers to exchange
information. This way it becomes possible (though complex) to develop an
authentication system for example. Please refer to the documentation in the file
"doc/lua-api/index.rst" for more information on how to use Lua.