The Agent2Agent (A2A) Protocol repository defines an open standard for AI agent interoperability. It maintains the canonical Protocol Buffers specification (`a2a.proto`) that defines core data structures (AgentCard, Task, Message, Part, Artifact) and service interfaces for agent communication. The repository includes comprehensive documentation, build scripts for generating JSON Schema and SDK docs, and CI/CD pipelines for validation. Rather than being a runnable application, it serves as a specification foundation for implementing A2A-compliant agents across multiple languages and frameworks. The protocol supports multiple bindings (JSON-RPC, gRPC, HTTP/REST), features like agent discovery via Agent Cards, task-based interaction patterns, streaming, push notifications, and enterprise capabilities including multi-tenancy and modern OAuth 2.0 flows.

This repository implements the Agent-to-Agent (A2A) protocol in Python. It is a comprehensive SDK providing both server and client libraries for building interoperable agent systems. The architecture is modular with abstract interfaces (AgentExecutor, TaskStore, ClientTransport) and supports multiple transports: JSON‑RPC, REST/HTTP+JSON, and gRPC, with a full backward‑compatibility layer for v0.3. Key features include agent card signing/verification (JCS canonicalization), push notifications, event streaming, and database persistence via SQLAlchemy. The codebase is well-structured with extensive automated testing (unit, integration, cross‑version, and conformance), CI/CD pipelines, and release automation. While primarily an SDK for protocol compliance, it also includes a sample agent application and an interop test kit.