h1spec

HTTP/1.1 conformance testing tool, in the spirit of h2spec.

Point it at any HTTP server to verify RFC 9112/9110 compliance.

Usage

# Run against a server
uvx --from git+https://github.com/dropseed/h1spec h1spec localhost:8000

# Strict mode (includes edge-case tests)
h1spec --strict localhost:8000

# Skip hardening checks
h1spec --no-hardening localhost:8000

# Run specific sections
h1spec --section headers --section body localhost:8000

Test sections

• Request Line (RFC 9112 S3) — method, target forms, version
• Headers (RFC 9112 S5) — Host validation, header syntax
• Body (RFC 9112 S6-7) — chunked encoding, Content-Length, Expect
• Response Semantics (RFC 9110) — HEAD, error delimiting
• Connection (RFC 9112 S9) — keep-alive, pipelining, close
• Hardening — oversized requests, header floods

Credits

Most of this was written by Codex and Claude.