The conduit library takes care of establishing and listening for TCP and SSL/TLS connections for the Lwt and Async libraries.
The reason this library exists is to provide a degree of abstraction from the precise SSL library used, since there are a variety of ways to bind to a library (e.g. the C FFI, or the Ctypes library), as well as well as which library is used (just OpenSSL for now).
By default, OpenSSL is used as the preferred connection library, but you can force the use of the pure OCaml TLS stack by setting the environment variable CONDUIT_TLS=native when starting your program.
The opam packages available are:
"conduit: the main Conduit moduleconduit-lwt: the portable Lwt implementationconduit-lwt-unix: the Lwt/Unix implementationconduit-async the Jane Street Async implementationconduit-mirage: the MirageOS compatible implementationSome of the Lwt_unix-based modules use a non-empty CONDUIT_DEBUG environment variable to output debugging information to standard error. Just set this variable when running the program to see what URIs are being resolved to.