Protocol Landscape

The Verifiable Intent (VI) core specification (spec/) is intentionally protocol-agnostic. It defines credential formats, delegation chains, and verification procedures without referencing any particular payment protocol or agent framework.

Protocol versions: The pages in this section are based on the Universal Commerce Protocol (UCP) specification as of 23 January 2026, the Agent Payments Protocol (AP2) specification as of 16 September 2025, and the Agentic Commerce Protocol (ACP) specification as of 30 January 2026.

The Protocol Ecosystem page explains VI's relationship to existing agentic commerce protocols. UCP and ACP handle payment transport; VI handles authorization proof. The page covers specific integration points for each protocol (UCP's AP2 Mandates Extension and ACP's extension mechanism) and why VI credentials ride alongside either without transport-layer changes.

The Cross-Protocol Glossary provides detailed term-by-term mappings across VI, UCP/AP2, and ACP. Tables cover roles, credential layers, execution flows, integrity mechanisms, and all five registered VI constraint types. Recurrence mapping is documented separately as a top-level payment mandate field (not a constraint). Reverse mappings list UCP/AP2 and ACP terms that have no VI equivalent, with explanations of why.

Contributing

To propose an integration mapping for a new protocol:

1. Open an issue describing the target protocol, its relevance to agentic commerce, and the expected audience.
2. Reference the glossary for shared terminology and add new columns for your protocol where applicable.