# Compose an HTTP request signature base

Build-time release reference. Runtime readiness, deployment, payment settlement and external indexing are not evaluated here. Prices are proposed; this file cannot authorize execution or payment.

Compose inert ASCII RFC 9421 request signature-base and Signature-Input artifacts from ordered, supplied non-secret field examples and explicit context. Does not sign, verify, authorize or send requests.

Release: 0.29.0. Built: 2026-10-06T15:38:00Z.

## Choose for
- Build an inert signature-base example from supplied request context and ordered ASCII field lines
- Compare raw and binary-wrapped field boundaries before using an external signer

## Outside this profile
- Signing, verification, keys, credentials, authentication, authorization, payment, or live HTTP requests
- Responses, trailers, CONNECT, query-parameter selection, Structured Field parsing, Unicode or obs-text fields
- Secret or production request payloads, including secrets in targets, free text or key identifiers

Proposed nominal USD 0.006 per successful call; payer fees excluded. No verified runtime availability.

- [Exact release contract](/reference/services/http-signature-base-compose.json)
- [Input schema](/reference/schemas/http-signature-base-compose.input.json)
- [Output schema](/reference/schemas/http-signature-base-compose.output.json)
- [Fixed example](/reference/examples/http-signature-base-compose.json)
- [Complete HTML reference](/discover/tools/http-signature-base-compose)