Perinci::Access::HTTP::Server is a PSGI application (a set of middlewares in Plack::Middleware::PeriAHS::*, really) to implement Riap::HTTP server. You compose the middlewares, configuring each one and including only the ones you need, in your app.psgi, to create an API service.
A simple command-line utility, peri-htserve, is included. This utility runs a provided PSGI application with the Gepok or Starman PSGI server so you can quickly export some Perl modules/functions as an API service with one line of command.
To get started, currently see the source code for peri-htserve and each middleware's documentation.