Web

Request → envelope

Envelope field	From
@web.req.method	HTTP verb
@web.req.url.{full,scheme,path,hostname,port,query.<k>.0,query.raw}	URL parts; query values are arrays
@web.req.headers.<name>	Headers (arrays)
@web.req.cookies.<name>	Parsed cookies
@web.req.body	Body, base64-encoded
@web.req.host / @web.req.proto	Host header / protocol
@rid	From X-Request-ID, or a fresh UUID

Envelope → response

Rules (or ops) shape the response by writing:

• @web.res.status — defaults to 200
• @web.res.headers.<name> — response headers
• @web.res.body — base64; decoded and written raw

With no @web.res.body, the response is the merged envelope as JSON, with _-prefixed fields stripped (the privacy convention).

Streaming: setting @web.res.body in a non-terminal scope locks the status + headers and switches to chunked transfer — each subsequent chunk flushes immediately, with natural backpressure (the processor blocks until the flush completes). HEAD requests and 1xx/204/304 statuses omit body bytes.

Limits and timeouts

• Headers capped at 256 KiB.
• The per-request deadline derives from --op-timeout-max (10m) — deliberately separate from --web-write-timeout (15s), which guards header reads (slowloris), so long-running ops aren’t cut off by the socket timeout.

TLS

Plain HTTP by default — a front proxy terminates TLS. With --web-tls-addr (e.g. :8443) the chassis terminates TLS itself, serving certificates per SNI from its cert manager (ACME DNS-01; requires the dns personality and --acme-email).

Special request signals

Signal	Effect
?_txc.continuation=<id>	Poll a suspended run (continuations)
?_txc.break=N or =stack/N	Breakpoint gate — only with --debug-breakpoints
X-Txco-Mocks: <patterns>	Request-scoped mock patterns — only with --web-mock-header
_txc.admission.* (set by rules)	Denials translate to HTTP status + headers before normal render