UCP AP2 Mandates Extension

Before writing code

Fetch live spec:

• Web-search site:ucp.dev specification ap2-mandates for the extension schema
• Fetch https://ucp.dev/2026-01-23/documentation/ucp-and-ap2/ for the conceptual relationship
• Web-search site:ap2-protocol.org for the AP2 protocol specification

Conceptual Architecture

What AP2 Enables

AP2 (Agent Payments Protocol) enables fully autonomous agent commerce — the agent can authorize payments cryptographically without requiring real-time human approval for each transaction. The user pre-authorizes spending parameters, and the agent proves authorization via signed credentials.

Two Mandate Artifacts

1. Checkout Mandate (ap2.checkout_mandate): An SD-JWT+kb (Selective Disclosure JWT with Key Binding) credential that proves the user authorized the agent to complete this specific checkout at these specific terms.