Glossary
Agent Payments Protocol (AP2)
The Agent Payments Protocol (AP2) is Google's specification for cryptographic proof of payment authorization — who approved a purchase, spending limits, and which merchants are allowed — kept separate from what was ordered. It plugs into UCP.
AP2 v0.2.0 added “Human Not Present” payments, letting an agent purchase autonomously within pre-set rules, and Google donated the protocol to the FIDO Alliance to move governance to a neutral standards body.