Building Web Applications With Erlang Drmichalore May 2026

start_child() -> Dispatch = cowboy_router:compile([ '_', [ "/", my_handler, [] ] ]), ok, _ = cowboy:start_clear(my_http_listener, [port, 8080], #env => #dispatch => Dispatch ). rebar3 shell Visit http://localhost:8080 4. Adding JSON API Using jiffy (fast C-based JSON):

handle(Req, State) -> Body = jiffy:encode(#status => ok, data => [1,2,3]), Req2 = cowboy_req:reply(200, #<<"content-type">> => <<"application/json">>, Body, Req), ok, Req2, State. Implement cowboy_websocket behavior: Building Web Applications With Erlang Drmichalore

terminate(_Reason, _Req, _State) -> ok. In src/my_web_app_sup.erl , add a child: Dispatch = cowboy_router:compile([ '_'

-behaviour(cowboy_websocket). init(Req, State) -> cowboy_websocket, Req, State. [] ] ])