Appendix B: Comparison to Existing Protocol Standards
How LCP relates to MPP, ACP, UCP, x402, AP2, TAP, Agent Pay, Verifiable Intent, A2A, and MCP.
The following table compares LCP's capabilities against the major agentic commerce and agent infrastructure protocols.
Comparison Table
| Feature | LCP | MPP | ACP | UCP | x402 | AP2 | TAP | Agent Pay | Verifiable Intent | A2A | MCP |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Terms discovery | Yes | No | No | URLs only | No | No | No | No | No | No | No |
| Terms identified by hash | Level 2+ | No | No | No | No | No | No | No | No | No | No |
| Explicit acceptance | Level 3 | No | No | Partial | No | No | No | No | No | No | No |
| Dispute resolution | Level 4 | No | No | No | No | Partial | No | No | No | No | No |
| Payment processing | No | Yes | Yes | Yes | Yes | Yes | Via Visa | Via MC | No | No | No |
| Checkout lifecycle | No | No | Yes | Yes | No | No | No | No | No | No | No |
| Agent identity | No | No | Partial | Partial | No | Partial | Yes | Yes | No | Partial | No |
| Consumer authorization | No | No | No | Partial | No | Yes | Yes | Yes | Yes | No | No |
| Agent-to-agent communication | No | No | No | No | No | No | No | No | No | Yes | No |
| Agent-to-tool connectivity | No | No | No | No | No | No | No | No | No | No | Yes |
Summary
LCP is complementary to all of these protocols. It provides the legal context layer — terms discovery, verification, signed acceptance, and dispute resolution hooks — that every other protocol defers. The authorization protocols (TAP, Agent Pay, Verifiable Intent, AP2) provide the consumer side; LCP provides the merchant side. Together they form a complete agreement. See Protocol Integration for per-protocol integration patterns and Relationship to Authorization Protocols for the relationship to authorization protocols.