nhttpc

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

Getting started

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

One-shot requests

{ok, #{status := 200, body := Body}} =
    nhttpc:get(<<"https://api.example.com/users/42">>).

{ok, Resp} = nhttpc:post(
    <<"https://api.example.com/users">>,
    <<"{\"name\":\"alice\"}">>,
    #{headers => [{<<"content-type">>, <<"application/json">>}]}).

Connection pools

{ok, _} = nhttpc:start_link(api_pool, #{
    host => <<"api.example.com">>,
    port => 443,
    versions => [http2, http1_1]
}).

{ok, Resp} = nhttpc:get(<<"https://api.example.com/users">>,
                        #{via => {pool, api_pool}}).

Async requests

Every async surface delivers {nhttpc, Handle, Event} to its owner. cancel/1 returns only after draining those events from the mailbox.

{ok, Req} = nhttpc:url(get, <<"https://api.example.com/users/42">>),
{ok, H} = nhttpc:send(Req),
{ok, Resp} = nhttpc:await(H, 5_000).

Features

• HTTP/1.1 (RFC 9112) and HTTP/2 (RFC 9113) with protocol selection via TLS ALPN
• HTTP/3 over QUIC (RFC 9114)
• WebSocket (RFC 6455) on the same handle protocol as async requests
• Three dispatch modes: one-shot, pooled, or on a caller-owned connection, selected by via
• Connection pools that pack HTTP/2 and HTTP/3 streams onto warm connections and grow on stream slots and send credit
• Streaming downloads and uploads with explicit consumer backpressure
• Retries with backoff, method-aware and off by default
• Redirects with a hop cap and credential stripping across origins
• Cookie jar (RFC 6265) on ETS
• Secure defaults: TLS peer verification against the system CAs
• Sealed error taxonomy: every public spec returns {error, nhttpc:error()}
• Telemetry events and OpenTelemetry metrics (opt-in)

Documentation

nhttpc on HexDocs

License

Apache License 2.0