{
  "name": "visa-tap-agent-verification",
  "domain": "AI & Agent Governance",
  "title": "Visa TAP Agent Verification (RFC 9421 Web Bot Auth + Nonce + JWKS Pin)",
  "description": "Four independent verification facts about a caller-captured Visa TAP-shaped agent request: the RFC 9421 Ed25519 Web Bot Auth signature base (art-129), the request's nonce format/freshness/replay-set membership per TAP's 8-minute window (art-593), a caller-pinned SHA-256 digest match against the caller-supplied JWKS directory document (art-609), and the directory's own shape plus keyid resolution (art-130, reused unmodified). Verification only -- zero network, zero key hosting, never a facilitator or transaction-path role.",
  "composer_url": "https://ainumbers.co/chaingraph/chains/visa-tap-agent-verification.html",
  "regulatory_basis_status": "not_assessed",
  "regulatory_basis_decided_by": "BUILD-BOTAUTH-VISATAP-CHAIN-1",
  "regulatory_basis_decided_at": "2026-08-17",
  "steps": [
    {
      "tool_id": "art-129-webbotauth-signature-verifier",
      "handoff": "Ed25519 signature verdict over the RFC 9421 signature base establishes whether the caller-captured request signature is genuine, ahead of the nonce and directory checks below."
    },
    {
      "tool_id": "art-593-webbotauth-nonce-replay-check",
      "handoff": "Nonce format, the TAP created/expires spread, and caller-supplied replay-set membership are assessed next -- a separate fact about the same captured request, independent of the signature verdict above."
    },
    {
      "tool_id": "art-609-jwks-pinned-directory-check",
      "handoff": "The caller-supplied JWKS directory document's canonical digest is checked against the caller's own out-of-band pinned digest before the directory's internal shape is trusted by the next step."
    },
    {
      "tool_id": "art-130-signature-directory-validator",
      "handoff": "Terminal stage: JWKS directory shape and keyid resolution are validated on the same pinned document, completing the four-fact TAP verification surface."
    }
  ]
}