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.
AG2 is a production-grade Python framework for building multi-agent AI systems. It provides a unified agent abstraction with support for multiple LLM providers (OpenAI, Anthropic, Gemini, Mistral, Bedrock, Ollama, xAI, Z.AI, DashScope), protocol integrations (A2A, A2UI, MCP, ACP), and sandboxed code execution (Docker, Daytona, local). The architecture is event-driven with a modular middleware pipeline, dependency injection, and a streaming event bus. It includes a full evaluation suite with trace reconstruction, scorers, pairwise comparison, and result persistence. The network layer enables distributed agent coordination via a hub-and-channel model with WAL persistence, identity management, and transport-agnostic envelopes. The framework also supports real-time voice interaction, skills-based toolkits, knowledge stores, and human-in-the-loop workflows. While the surface area is large, the codebase demonstrates high craftsmanship with clean abstractions, protocol-based interfaces, and extensive test coverage across all modules.
The google/adk-go repository is a production-grade, open-source Go framework for building, orchestrating, and deploying multi-agent AI systems. It provides a comprehensive set of abstractions including agents, workflows, tool integrations, model backends (Gemini, OpenAI, Apigee), session management, artifact storage, and human-in-the-loop (HITL) support. The architecture centers around a workflow engine that supports graph-based execution with nodes, edges, retry, concurrency, and dynamic branching. It also implements agent-to-agent (A2A) and Model Context Protocol (MCP) for inter-agent communication. The framework is designed to be deployed via REST API, WebSocket, SSE, or as a console application, and includes launchers for Google Cloud Run and Vertex AI Agent Engine. While primarily an application framework, it also includes telemetry and analytics plugins for observability. The codebase is well-structured with extensive unit and integration tests, but some internal packages and experimental features (e.g., OpenAI model adapter) indicate ongoing development and potential for interface drift.
EvoMap Evolver is a self-evolving AI agent engine built as a Node.js >=22.12 CLI daemon. It runs a genome-evolution loop: scans session memory/logs, extracts signals, selects 'Genes' (prompt/strategy patches) and 'Capsules' (validated skill bundles) from a local JSON/JSONL asset store, generates GEP-framed prompts for coding agents (Claude Code, Codex, Cursor, Gemini CLI, opencode, Kiro), executes those sessions, and records outcomes in a memory graph to adapt future selections. The system solidifies successful patterns into new reusable assets, auto-distills failure patterns and SKILL.md files into Genes/Capsules, and can open PRs or run validation sandboxes against candidate changes. It also ships an LLM proxy (Anthropic/OpenAI/Gemini/Vertex/Ollama routes with trace encryption and token-savings attribution), an ATP (Agent Transaction Protocol) marketplace for buying/completing agent tasks with auto-buyer and auto-deliver, a validation daemon for decentralized task verification, a local Web UI dashboard, and an experiment runner for A/B comparing evolution strategies. Hub synchronization (SSE event delivery, mailbox sync, OAuth device login) connects nodes to the evomap.ai network, but the system is designed to degrade gracefully into fully offline solo mode.
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.
Solace Agent Mesh is a production-grade, full-stack platform for building, deploying, and managing event-driven multi-agent AI systems. It comprises a Python backend (FastAPI, Google ADK, SAC), a React/TypeScript web UI (chat, projects, workflows, prompts, scheduled tasks), a Click-based CLI, and a Docusaurus documentation site. The system uses a microservices-like architecture with separate gateway (HTTP/SSE), platform service (model configuration, storage), and agent components, all communicating via the Solace event broker and the A2A (Agent-to-Agent) protocol. Key entry points include the CLI (`solace-agent-mesh`), the web UI (`/chat`, `/projects`, `/workflows`), and the REST API (`/api/v1`). Data flows involve user requests via SSE, agent orchestration with workflow DAGs, tool execution (built-in, MCP, OpenAPI), artifact storage (S3/GCS/Azure/filesystem), and session persistence in SQL databases (SQLite/PostgreSQL/MySQL). External dependencies include a Solace broker, LLM endpoints (LiteLLM), optional databases, and cloud storage services. The repository is marked as deprecated (Development Status 7 – Inactive), with the new version being a desktop application.