---
title: "RFC 9421 Signature Decoder & Web Bot Auth Readiness"
method: POST
path: "/v1/tools/decode_http_message_signature"
tags: ["RFC 9421", "HTTP Message Signatures", "Web Bot Auth", "Ed25519", "Visa Trusted Agent Protocol", "agent identity"]
---

# RFC 9421 Signature Decoder & Web Bot Auth Readiness

`POST /v1/tools/decode_http_message_signature`

## Request

- Base URL: `https://ainumbers.co`
- URL: `https://ainumbers.co/v1/tools/decode_http_message_signature`
- Auth: none declared

Decodes and validates RFC 9421 HTTP Message Signatures (Signature-Input / Signature), lints a Web Bot Auth JWKS directory (Ed25519), and scores Web Bot Auth readiness. This is the signature substrate Visa Trusted Agent Protocol builds on. Reference rules are static and may age — verify against RFC 9421 and the Web Bot Auth draft. Does not perform cryptographic signature verification.

**Tool URL:** https://ainumbers.co/tools/279-rfc9421-signature-webbotauth.html
**AP2/Policy Mandate export:** yes

## Request body

- object
  - `signature_input` string: The Signature-Input header value.
  - `signature` string: The Signature header value.

## Response `200`

Successful tool execution result

- object
  - `parsed` object
  - `findings` unknown[]
    - unknown

---

[API](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite.md) · [All operations](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite/llms.txt) · [OpenAPI document](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite/revisions/b462e4f5bb28?raw)