$ show a2aproject/a2a-python
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.
The LLM identified 3 files worth highlighting for reuse:
Implements RFC 8785 JSON Canonicalization Scheme (JCS) for deterministic JSON serialization. Handles number formatting, Unicode key ordering, and depth‑bounded recursion. Includes comprehensive conformance tests against independent oracles. Self‑contained and extractable for any project requiring reproducible JSON signing or hashing.
A simple decorator wrapper around any TaskStore implementation that deep‑copies all returned Task objects, preventing accidental mutation of shared state. This is a clean, single‑responsibility pattern useful anywhere mutable objects cross boundaries. Requires only the abstract TaskStore interface, making it trivially extractable.
A corpus of 57 RFC 8785 conformance test vectors (47 must‑accept, 10 must‑reject) covering signatures exclusion, key ordering, string/number serialization, and nesting. Each vector references specific spec clauses and was validated against two independent oracles. This artifact is reusable by any A2A implementation or JCS library for testing canonicalization correctness.