A2A (Agent-to-Agent) is a protocol for agents to discover, communicate and transact with one another. In the payments context it standardizes how one agent pays another for a task or service, forming the settlement layer of multi-agent systems.
Agent-to-Agent (A2A)
A2A projects, ranked
Live from the directory · sorted by GitHub stars. Showing the top 40 of 194.
A local-first AI agent with persistent memory, emotional intelligence, and a peer-to-peer skills economy.
The A2A x402 Extension brings cryptocurrency payments to the Agent-to-Agent (A2A) protocol, enabling agents to monetize their services through on-chain payments. This extension revives the spirit of HTTP 402 "Payment Required" for the decentralized agent ecosystem.
The trust layer for agent-to-agent commerce — natural-language mandates, ERC-7710 delegated permissions, x402 payments, escrow, and dispute resolution as one open, catch-all Agent Skill / Claude Code plugin.
A small, powerful, open-source CLI coding agent that works with open models.
Beacon - agent-to-agent pings with optional RTC value attached (BoTTube/Moltbook/RustChain + UDP bus)
AI agents platform that gives you a workspace with an integrated team of personal assistants that can work behind the scenes to handle daily monotonous tasks.
Lucid Agents Commerce SDK. Bootstrap AI agents in 60 seconds that can pay, sell, and participate in agentic commerce supply chains. Our protocol agnostic SDK provides CLI-generated templates and drop-in adapters for Hono, Express, Next.js, and TanStack, giving you instant access to crypto/fiat payment rails (AP2, A2A, x402, ERC8004).
An operating system built for AI agents — talk to your NixOS server instead of SSH-ing in. Typed, audited tool access with atomic rollback on every change. Research-grade; run it on a disposable box, not production.
A complete TypeScript implementation of the Python x402 payment protocol extension for A2A (Agent-to-Agent) communication. Enable your AI agents to request, verify, and settle crypto payments seamlessly.
Next.js-like framework building AI Agents that are payment-native. Bootstrap your agent with A2A, MCP, x402 payments, and ERC-8004 identity.
Connect AI agents across any network — zero config, encrypted, skill-based routing
The way AI coordinates and transacts. Routing and settlement layer for your agent economy.
Join.cloud lets AI agents work together in real-time rooms. Agents join a room, exchange messages, commit files to shared storage, and optionally review each other's work — all through standard protocols (MCP and A2A).
npx CLI that scaffolds blockchain-registered AI agents with on-chain identity (ERC-8004), A2A communication, MCP tool serving, and optional USDC micropayments across EVM and Solana.
Bidirectional bridge between Claude Code and OpenAI Codex CLI. Built on Claude Code Channels. Two AI agents, one conversation, real-time web UI.
🤖 AI-Mocks is a Kotlin-based toolkit for mocking and testing LLM APIs with real streaming and SSE support. Simulate OpenAI, Anthropic, Gemini, Ollama, and A2A services locally for reliable integration testing.
Skills & plugins for agentic commerce : UCP, ACP, AP2, A2A, WebMCP, Magento 2, BigCommerce, WooCommerce
AI-powered flood intelligence system featuring h2oGPTe Agent + NVIDIA NIM integration (A2A), NAT pipeline with Nemotron 49B, and real-time flood risk assessment. Part of NVIDIA–H2O.ai AI for Good Blueprint for disaster response and monitoring.
A collection of Summoner clients and agents featuring example implementations and reusable templates
Tooling for building applications with x402 payment capabilities. Supports buyer and seller roles.
Drop-in adapters connecting 50+ agent frameworks (LangChain, CrewAI, AutoGen, OpenAI Agents, MCP, A2A, x402) to the Agoragentic marketplace: route a task with execute(), get a receipt, settle in USDC on Base. Monorepo + npm packages for MCP, Micro ECF, and local readiness tooling.
Demo agents showcasing CapiscIO Agent Guard and MCP Guard — trust badges, identity verification, and tool-level authorization for A2A and MCP protocols
A curated list of Agent-to-Agent (A2A) libraries and SDKs, organized by programming language.
The first AI agent marketplace. 5,750+ community, 51+ API endpoints, 85% commission. Powered by CashClaw v1.7.0.
540 security tests for AI agent systems — MCP, A2A, x402/L402, decision governance, benchmark integrity, skill supply chain. AIUC-1 pre-cert, NIST AI 800-2 aligned, MCP tool-poisoning reproduction. v4.9.1
Demos and starter code for building agentic finance apps with Crossmint
Cross-vendor agent-to-agent protocol — Claude, Codex, and Gemini communicate via file-based P2P messaging.
Elixir implementation of the Agent-to-Agent (A2A) protocol (https://a2a-protocol.org).
Demo with multiple AI agents using A2A (agent-to-agent) with the Strands Agents SDK.
AI agent stack that combines A2A messaging + x402 micropayments + ERC‑8004 identity(trustless agent).
AI agent stack that combines A2A messaging + x402 micropayments + ERC‑8004 identity(trustless agent).
AI agent stack that combines A2A messaging + x402 micropayments + ERC‑8004 identity(trustless agent).
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Frequently asked questions
What is Agent-to-Agent (A2A)?
A2A (Agent-to-Agent) is a protocol for agents to discover, communicate and transact with one another. In the payments context it standardizes how one agent pays another for a task or service, forming the settlement layer of multi-agent systems.
How many A2A projects are there?
We track 194 open-source A2A projects, generated live from our ecosystem dataset and ranked by GitHub stars.
Where does A2A fit among agent payment protocols?
A2A is one of several standards in the agentic-payments stack (x402, MPP, A2A, AP2, ACP, L402, MCP). See our agent payment protocols overview for a side-by-side comparison.