nhttp

HTTP/1.1, HTTP/2, and HTTP/3 server for Erlang/OTP 27+.

Getting started

%% rebar.config
{deps, [nhttp]}.

Minimal server

-module(my_handler).
-behaviour(nhttp_handler).
-export([init/1, handle_request/2]).

init(_Args) ->
    {ok, #{}}.

handle_request(#{method := get, path := <<"/">>}, State) ->
    {reply, nhttp_resp:ok(<<"Hello, World!">>), State};
handle_request(_Req, State) ->
    {reply, nhttp_resp:not_found(), State}.

{ok, Pid} = nhttp:start_link(my_server, #{
    port => 8080,
    handler => my_handler
}).

See the examples/ directory for runnable handler skeletons covering plain HTTP, streaming responses, WebSocket, SSE, CORS, and chunked uploads.

TLS with HTTP/1.1 + HTTP/2 (ALPN)

{ok, Pid} = nhttp:start_link(my_server, #{
    port => 8443,
    versions => [http1_1, http2],
    handler => my_handler,
    tls => #{certfile => "server.pem", keyfile => "server.key"}
}).

HTTP/3 over QUIC

HTTP/3 runs over QUIC on a UDP socket. HTTP/1.1 and HTTP/2 run over TCP on their own socket. List all three versions and a single listener opens both sockets for you, and sets Alt-Svc on the TCP side so clients know where to find HTTP/3.

{ok, Pid} = nhttp:start_link(my_server, #{
    port => 8443,
    versions => [http1_1, http2, http3],
    handler => my_handler,
    tls => #{certfile => "server.pem", keyfile => "server.key"}
}).

%% nhttp:get_ports(Pid) => #{tcp => 8443, quic => 8443}

Features

• HTTP/1.1 (RFC 9112) and HTTP/2 (RFC 9113) with automatic protocol selection via TLS ALPN
• HTTP/3 over QUIC (RFC 9114), in-process nquic library mode
• WebSocket over HTTP/1.1 (RFC 6455), HTTP/2 (RFC 8441), and HTTP/3 (RFC 9220) with one callback set
• Server-Sent Events helpers (W3C SSE)
• CORS preflight and response header helpers (Fetch)
• PROXY protocol v1/v2 for HAProxy and AWS NLB deployments
• SNI with static lookup table and/or dynamic callback
• Streaming responses via producer funs with end-to-end backpressure
• Streaming request bodies with handler-driven backpressure
• Response compression (gzip / deflate) with MIME-aware defaults
• OpenTelemetry spans and metrics (opt-in)
• Graceful shutdown with connection draining
• One process per connection, with HTTP/2 and HTTP/3 streams multiplexed inside it

Documentation

nhttp on HexDocs

License

Apache License 2.0