HTTP.jl

HTTP.jl provides HTTP client/server functionality, HTTP/2 support, SSE, and WebSockets on top of Reseau's transport, resolver, and TLS stack. The high-level surface stays familiar while keeping request, response, body, transport, and stream types explicit.

Quick Start

This example starts a local server, sends a request through the client API, and reads the response body:

using HTTP

server = HTTP.serve!("127.0.0.1", 0; listenany = true) do req
    payload = "hello from HTTP.jl docs"
    return HTTP.Response(
        200;
        headers = ["Content-Type" => "text/plain"],
        body = payload,
    )
end

url = "http://127.0.0.1:$(HTTP.port(server))/hello"
resp = HTTP.get(url; proxy = HTTP.ProxyConfig())
HTTP.forceclose(server)
String(resp.body)

What You Get

• Familiar top-level request helpers: HTTP.get, HTTP.post, HTTP.request, HTTP.open
• Explicit client controls: HTTP.Client, HTTP.Transport, HTTP.RetryBucket, HTTP.ProxyConfig, HTTP.HTTP2Settings
• Rich client timeout controls: connect_timeout, request_timeout, response_header_timeout, read_idle_timeout, and write_idle_timeout
• Server entrypoints for request/response and stream-level handlers: HTTP.serve!, HTTP.listen!, HTTP.streamhandler
• Built-in HTTP/2 support in the normal client and server workflows
• Protocol-specific APIs for WebSockets

Documentation Map

• The Client guide covers request construction, streaming, reusable clients, request bodies, and operational knobs.
• The Server guide covers request handlers, stream handlers, lifecycle management, and SSE-oriented server patterns.
• The Protocols guide covers WebSockets and where HTTP/2 fits into the normal client/server APIs.
• The Migration guide calls out the major 1.x to 2.0 shifts.
• The API reference is the canonical home for exported and documented submodule APIs.

Docs for LLMs

The documentation is also published as plain markdown for LLM tooling, following the llms.txt convention:

• llms.txt: a short index of the documentation pages.
• llms-full.txt: every page, with all docstrings expanded, in a single file.

Give either file to an assistant when you ask it about HTTP.jl.

Design Direction

• HTTP.jl owns the HTTP protocol stack; Reseau owns the transport/runtime/TLS substrate.
• Request and response bodies have explicit internal representations while ordinary user-facing calls accept familiar strings, byte vectors, forms, and streams.
• Client/server internals follow a more explicit state-machine design, which makes retries, proxying, streaming, and HTTP/2 behavior easier to reason about.
• Most wire-level HTTP/2 and HPACK details are implementation details rather than part of the documented public API.