LCPLegal Context Protocol

References

Normative and informative references for the LCP specification.

Normative References

  • [RFC 2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
  • [RFC 8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, May 2017.
  • [RFC 8615] Nottingham, M., "Well-Known Uniform Resource Identifiers (URIs)", RFC 8615, May 2019.

Informative References

  • [RFC 3161] Adams, C., et al., "Internet X.509 Public Key Infrastructure Time-Stamp Protocol (TSP)", RFC 3161, August 2001.
  • [RFC 9421] Backman, A., et al., "HTTP Message Signatures", RFC 9421, February 2024.
  • Fisher, D. and McCormack, B., "Identity, Trust, and the Legal Foundations of Agentic Commerce", March 2026.
  • Ryan, B., Moxey, J., Meagher, T., Weinstein, J., and Kaliski, S., "The 'Payment' HTTP Authentication Scheme" (Machine Payments Protocol), IETF Internet-Draft draft-ryan-httpauth-payment-01, March 2026.
  • Ryan, B., Moxey, J., Sproule, R., and Ragsdale, S., "Service Discovery for HTTP Payment Authentication", Internet-Draft draft-payment-discovery-00, April 2026. Published at paymentauth.org.
  • OpenAI and Stripe, "Agentic Commerce Protocol", version 2026-04-17.
  • Google, "Universal Commerce Protocol", version 2026-04-08, April 2026.
  • Google, "Agent Payments Protocol (AP2)", v0.2, 2026.
  • Google, "Agent-to-Agent Protocol (A2A)", v1.0, March 2026. (Donated to Linux Foundation June 2025; v1.0 released March 2026.)
  • Anthropic, "Model Context Protocol", spec version 2025-11-25.
  • Visa, "Trusted Agent Protocol", October 2025.
  • Mastercard, "Verifiable Intent", 0.1-draft, February 2026.
  • Coinbase, "x402 Protocol", 2025.
  • [EIP-712] Bloemen, R., Logvinov, L., and Evans, J., "Typed structured data hashing and signing", Ethereum Improvement Proposal 712.

Security Considerations

Transport security, document integrity, terms versioning, ephemeral link security, privacy, rate limiting, and agent-side security considerations (prompt injection, autonomous signing, display-versus-signed divergence, replay across versions, signing-key compromise).

Appendix A: Worked Example

A single transaction scenario walked through each of the four trust levels in sequence — from informational to integrated.

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Normative ReferencesInformative References