The building blocks of Pedestal are not limited to web applications. The interceptor concept is very general and can be used in message-processing or dataflow applications just as well as request/reply web services.
A chain provider invokes a queue of interceptors in response to some
stimulus. The job of a chain provider is to accept incoming stimuli
(requests, messages, events, commands, etc.) set up the
context map and execute a queue of interceptors via
execute.
For HTTP, the servlet interceptor is the chain provider.
