Glossary
A2A
A2A is defined here as follows. Open protocol, hosted by the Linux Foundation, for agents to discover each other through Agent Cards and collaborate over HTTP. Requests and responses use JSON-RPC 2.0. The directory source for this term is A2A core concepts.
Last verified 2026-10-17
Sources
Listings
Directory listings whose sources describe this mechanism.
| Name | Status | Category | Open source | Mechanism |
|---|---|---|---|---|
| A2A | Live | Protocols | Yes | Open protocol, hosted by the Linux Foundation, for agents to discover each other through Agent Cards and collaborate over HTTP using JSON-RPC. discovery, agent-cards, json-rpc |
| AP2 | Beta | Payment rails | Yes | Open payment extension for A2A and UCP that records checkout and payment authorization as signed mandates. Public samples exist while FIDO continues the standards work. mandates, cards, stablecoins |
| Gensyn | Live | Exchanges and markets | No | Open infrastructure where humans and machines trade compute, data, and information in on-chain markets, with a peer-to-peer layer that carries MCP and A2A. compute, data, information |
| PACT | Beta | Protocols | Yes | Protocol on A2A 1.0 that lets a personal agent sign its requests and act for a user only inside scopes that user approved with a brand. consent, identity, a2a |
| Universal Commerce Protocol | Live | Protocols | Yes | Open commerce protocol so agents, businesses, and payment providers can negotiate checkout and identity linking over REST, MCP, or A2A. commerce, checkout, discovery |
Questions
- What is A2A?
- Open protocol, hosted by the Linux Foundation, for agents to discover each other through Agent Cards and collaborate over HTTP. Requests and responses use JSON-RPC 2.0.
- Which listings use A2A?
- A2A, AP2, Gensyn, PACT, Universal Commerce Protocol.
- When was A2A last verified?
- Last verified 2026-10-17.