II.
Topic overview
Reference · livetopic:a2a-protocol
Agent-to-Agent (A2A) Protocol overview
Agent-to-Agent (A2A) Protocol as a cross-cutting topic - Google's open protocol for inter-agent communication. A2A enables agents built on different frameworks and by different vendors to discover each other's capabilities (via Agent Cards), negotiate interaction modalities, and exchange structured messages, artifacts, and streaming updates. The protocol defines a JSON-RPC 2.0 transport, task lifecycle management (submitted, working, input-required, completed, failed, canceled), push notifications via webhooks, and SSE-based streaming for long- running tasks. Complementary to MCP (which connects agents to tools), A2A connects agents to other agents across organizational boundaries.
Attributes
displayName
Agent-to-Agent (A2A) Protocol
description
Agent-to-Agent (A2A) Protocol as a cross-cutting topic - Google's open
protocol for inter-agent communication. A2A enables agents built on
different frameworks and by different vendors to discover each other's
capabilities (via Agent Cards), negotiate interaction modalities, and
exchange structured messages, artifacts, and streaming updates. The
protocol defines a JSON-RPC 2.0 transport, task lifecycle management
(submitted, working, input-required, completed, failed, canceled),
push notifications via webhooks, and SSE-based streaming for long-
running tasks. Complementary to MCP (which connects agents to tools),
A2A connects agents to other agents across organizational boundaries.
Outgoing edges
applies_to1
- domain:software-engineering·DomainSoftware Engineering
Incoming edges
contains1
- domain:ml-ai·DomainML/AI
integrates_with2
- channel:a2a-example·ChannelA2A example channel
- framework:google-adk·FrameworkGoogle Agent Development Kit (ADK)
relates_to_topic1
- tool:agent-message-queue·ToolAgent Message Queue