Module http/client

Async HTTP client — fetch and fetch_with, shaped like JavaScript's fetch and configured like reqwest.

fetch(url, io) is a GET with defaults; fetch_with(url, opts, io) takes a FetchOptions carrying the method, headers, body, redirect cap, response ceiling and a deadline for the WHOLE exchange. Both speak plaintext over TcpStream and TLS over TlsStream (https is real TLS, not a stub), and both buffer the entire response into memory — which is why max_response_bytes exists and defaults to 64 MiB rather than being unlimited.

Each call is a fresh connection, and a Connection: close request header says so on the wire: there is no pool yet (see ## Stability). Failures throw IoExn carrying an HttpError (D1); a deadline that wins the race throws HttpError.Timeout and aborts the in-flight task, so a hung server cannot pin a caller forever.

{ fetch } :: import("std/http");
{ IoExn } :: import("std/error");

resp := io.await(fetch(`http://example.com/api/data`, io), IoExn(io : io, exn : exn));
println(resp.body);

Stability

unstable — the connection model is going to change. Every request sets Connection: close and reads through read_http_message, the framing form that DISCARDS whatever the peer sent past the message, so nothing here can reuse a connection today; the reusable framing landed in ./wire.yo on 2026-09-10 and the pool is the remaining piece. Its intended shape is decided — an HttpClient object that OWNS its idle connections (Rust's reqwest::Client), with an explicit lifetime and a Dispose that closes the idle set, rather than a module-global — and the free fetch/fetch_with are meant to keep their one-shot behaviour when it arrives, so this file grows a type rather than changing these two.

A second, smaller shape is open: a plaintext request connects to the FIRST address lookup_host returns and does not fall back to the next on failure, so a host whose IPv6 route is dead fails instead of reaching its IPv4 address (no happy-eyeballs, and the resolver order decides). That sits behind std/net/dns's own open questions.