Glossary

Term	Acronym	Definition	Synonym / Related
Action Authorization		A process where a Verifier challenges an Agent to provide proof that it is authorized to perform an action on behalf of a User.
Agent Payments Protocol	AP2	An open protocol designed to enable AI agents to securely interoperate and complete payments autonomously.
Agent Provider		An entity that provides the Agent to the User. Can also be a trusted party for Verifiers to construct Mandates directly.
Agent2Agent Protocol	A2A	An open standard for secure, collaborative communication and task management between diverse AI agents, regardless of their underlying frameworks. Context: AP2 can be implemented as an extension of A2A to facilitate financial transactions, with a focus on high-trust agentic payments.
Agentic payments		Payment flows in which autonomous AI Agents are facilitating the payment.
Checkout Mandate		A Mandate used for authorizing the completion of a checkout.
Closed Mandate		A Mandate that is bound to a particular action with a Verifier to authorize the agent to perform an action.
Credentials Provider	CP	A secure entity, like a digital wallet, responsible for managing and executing the user's payment and identity credentials.
Deterministic cryptographical proof		A unique mathematical proof that could be linked to a hardware device.
Dynamic Linking		A core requirement for Strong Customer Authentication (SCA), involving the inclusion of specific transaction details within a Payment Credential to link the SCA to that transaction. Context: Ensures the payer explicitly consents to transaction details like amount and payee.
Mandate Content		The specific payload of a Mandate created by the Shopping Agent and rendered to the User, detailing actions the agent handles.
Mandate Delegation		A process where a User authorizes an Agent to perform an action on their behalf.
Mandate Receipt		A Verifier-signed JWT indicating the result of the action authorization.
Merchant Endpoint (Or Remote Endpoint)	ME, RE	The web interface or AI agent representing the seller, showcasing products and negotiating the cart.
Merchant Payment Processor	MPP	The entity responsible for constructing and sending the transaction authorization message to the payment ecosystem.	Merchant PSP
Model Context Protocol	MCP	A protocol standardizing how AI models and agents connect to and interact with external resources like tools, APIs, and data sources.
Open Mandate		A Mandate that has not yet been bound to a particular action. It possesses constraints to be applied to a closed mandate to ensure it's validity.
Payee		A person or entity who is the intended recipient of funds from a payment transaction. Context: Can request attestations along with payment confirmation.	Merchant, Creditor Name
Payer		A person or entity who holds a payment account, allows a payment order from that account. Context: Initiates payment orders.	User, Holder
Payment Agent		A proposed key role in agent payments responsible for selecting the ideal payment method, validating payment details, and handling errors. Context: A Payment Agent is not a necessary requirement to participate in the protocol. MCP-based endpoints can also play similar roles.
Payment Credential		A credential or instrument (or reference to one) which can be charged towards a payment.	Electronic Attestation of Attributes (EAA), Payment Wallet Attestation (PWA), Digital Payment Credentials (DPC), Payment Means Attestation, SPC Credential
Payment Initiation Service Provider	PISP	A service provider that initiates payments on behalf of the user.
Payment Mandate		A Mandate used for authorizing the payment for a particular checkout.
Strong Customer Authentication	SCA	A process required by regulatory frameworks for online identification and transaction initiation in financial services. Context: Central to the Payments Rulebook, ensuring security and dynamic linking of transactions.	Strong User Authentication, Integrated SCA
Trusted Surface		A secure, non-agentic interface that renders Mandate Content to the User for authorization and consent. The result of which is a Mandate.
Universal Commerce Protocol (UCP)		A protocol providing a Checkout Object standard when used with the Checkout Mandate.
User		The human initiating the task and providing financial authority.
User Agent a.k.a. Shopping Agent	UA, SA	The AI surface interacts directly with the user, understanding their needs, and coordinating the purchase.
Verifiable digital credential	VDC	An Issuer-signed credential (i.e., a set of Claims) whose authenticity can be verified. Context: Typically bound to a cryptographic key and used in the issuer-holder-verifier model.	Digital credential, Verifiable Credential
Verifiable Presentation	VP	A presentation of one or more VDCs that includes a cryptographic proof of holder binding, created in response to a request from a Verifier. Context: Allows a Verifier to confirm that the Holder intended the presentation for them and may reveal only a subset of claims.