Glossary
| Term | Acronym | Definition | Synonym / Related |
|---|---|---|---|
| Agent Payments Protocol | AP2 | An open protocol designed to enable AI agents to securely interoperate and complete payments autonomously. | |
| 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 involved. | ||
| 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. | ||
| 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 Endpoint | MPP | The entity responsible for constructing and sending the transaction authorization message to the payment ecosystem. | |
| 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. | |
| 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 Contracts | "Mandates" or "Payment Contracts" that capture a user's specific instructions to their agent. Context: Define principles for safe, secure, and high-trust agentic payments. They can be global or transaction-level. | Mandates, Shopping Mandate | |
| 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 Request API (W3C Standard) | A web API that acts as an intermediary between a merchant, user, and payment method provider to streamline the payment experience. | ||
| 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 |
| 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 Credential | VC | 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 Presentation | VP | A presentation of one or more VCs 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. |