AP2

This section is advisory.

AP2 is an open protocol (Apache 2.0) created by Google for secure AI-agent-driven payments. It uses W3C Verifiable Digital Credentials (VDCs) implemented as SD-JWT with Key Binding. 100+ partners including Mastercard, PayPal, American Express, and Coinbase.

Three Mandate Types

AP2 defines three mandate types:

• Cart Mandates (human-present) — user signs the exact cart. Includes a merchant cryptographic signature guaranteeing fulfillment and refund conditions.
• Intent Mandates (human-not-present) — user delegates within constraints (spending caps, merchant categories, validity windows).
• Payment Mandates — for the payments ecosystem, carrying authorization through the payment network.

LCP Alongside Mandates

AP2 mandates capture what was authorized — the user approved this cart or delegated this intent. LCP captures what terms govern the authorization — what the merchant offered, what dispute resolution applies, what obligations extend beyond payment. These are complementary:

AP2 Cart Mandate: "User approved purchase of items X, Y, Z for $500"
LCP reference:    "Terms governing this purchase are at hash 0x7f83...,
                   jurisdiction NY, AAA arbitration, 30-day return policy"

The LCP reference SHOULD travel alongside the mandate — either in the A2A transport metadata layer or in an AP2 extension field. When the mandate and the LCP reference are both present, the combination creates a complete record: who authorized what, under what terms.

Intent Mandate Enrichment

For autonomous (human-not-present) mandates, the natural language intent can be paired with machine-readable LCP constraints specifying the legal framework within which the agent may act. This extends the agent's authorization from financial constraints (spending caps, merchant categories) to legal constraints (acceptable jurisdictions, required dispute resolution methods, maximum contract duration).

Dispute Evidence Integration

AP2 defines a dispute evidence framework with liability allocation tables for scenarios including first-party fraud, agent mispicks, merchant non-fulfillment, and account takeover. The LCP contentHash and agreement record provide additional evidence:

• What terms were in effect at transaction time
• Whether the merchant's offer matched the terms at transaction time
• What dispute resolution process was specified

The combination of AP2's liability allocation tables and LCP's terms record creates a complete evidentiary foundation for dispute resolution.