Agent2Agent Protocol (A2A)
Open protocol for agents built on different frameworks and vendors to discover each other and collaborate on tasks.
Reference by Created by Google; contributed to the Linux Foundation
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About
Use cases: agent-orchestration
Reviews
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About the protocol
- Specification
- a2a-protocol.org/latest/specification/
- Current version
- v1.0.1github.com
- Maintainer
- Created by Google; contributed to the Linux Foundationlinuxfoundation.org
- Governance
- Linux Foundation project, listed under the Agentic AI Foundationaaif.io
- Launched
- 2025-04-09developers.googleblog.com
- Launched with support and contributions from more than 50 technology partners. developers.googleblog.com
- Linux Foundation announced the A2A project on 2025-06-23 with Google, SAP, ServiceNow and Cisco among early participants. linuxfoundation.org
Listings that use it
1,123 visible listings declare Agent2Agent Protocol (A2A): 1,099 agents, 15 harnesses & sdks, 7 agent infrastructure, 2 identity, auth & payments.
Agents
- 0.689score
GPT Researcher
GPT Researcher
Open-source research agent that plans questions, searches the web or your documents in parallel and writes a cited report with any LLM.
AgentAFreshness: A★ 30.3K↓ 8.5K/wk - 0.665score
AutoDev
Phodal Huang
Multi-agent development platform built on Kotlin Multiplatform, with IDE plugins, a CLI, desktop, mobile and web targets.
AgentAFreshness: A★ 4.6K - 0.609score
opencrabs
opencrabs
Single Rust binary for an autonomous, self-improving agent with TUI, CLI and daemon modes and connections to many chat channels
AgentAFreshness: A★ 1K - 0.563score
open-instinct
mariagorskikh
Open-source personal agent you text over iMessage, running in its own cloud microVM with app connectors and approval-gated payments.
AgentAFreshness: A★ 397 - 0.453score
AssetFare Route Quotes
AssetFare
AssetFare is a non-custodial service with 100 technically available routes.
AgentCFreshness: C - 0.453score
Agent Reputation
Agent Reputation
Agent Reputation runs the Complaint Bureau: a registry of complaints about paid agent transactions, where entry requires a signature from one of the two…
AgentCFreshness: C
Harnesses & SDKs
- 0.778score
AgentScope Java
Alibaba Tongyi Lab
Java framework for distributed, long-running agents with typed event streams, permission gating, middleware and subagents.
HarnessAFreshness: A★ 6.1K - 0.777score
ADK for TypeScript
Google
TypeScript toolkit for agents with Zod-typed tools, graph and multi-agent workflows, and Node.js or browser runtimes.
HarnessAFreshness: A★ 1.4K↓ 143.5K/wk - 0.757score
atmosphere
Atmosphere
Java runtime for AI agents that streams tokens and tool events over WebSocket, SSE or gRPC, with human approvals.
HarnessAFreshness: A★ 3.8K - 0.752score
PraisonAI
Mervin Praison
Python framework for multi-agent teams and workflows, with a CLI and Docker, MCP and A2A deployment options.
HarnessAFreshness: A★ 9.3K↓ 4.6K/wk - 0.745score
BeeAI Framework
IBM / Linux Foundation
Python and TypeScript framework for multi-agent systems, with MCP and A2A interop, YAML orchestration and OpenTelemetry tracing.
HarnessAFreshness: A★ 3.4K↓ 5.4K/wk - 0.727score
Agno
Agno
Python framework and runtime for building agents, serving them over a REST API and MCP server, and managing them from a web control plane.
HarnessAFreshness: A★ 42.9K↓ 519.4K/wk
Agent infrastructure
- 0.867score
LiteLLM
BerriAI
Open-source AI gateway with a Python SDK that calls 100+ LLM providers through the OpenAI format.
InfrastructureAFreshness: A★ 62Kgateway - 0.860score
Kong AI Gateway
Kong
Cloud-native API, LLM and MCP gateway with multi-LLM routing, AI analytics and an extensible plugin system.
InfrastructureAFreshness: A★ 44.3Kgateway - 0.751score
agentgateway
agentgateway (Linux Foundation)
Open source gateway for HTTP, gRPC, LLM, MCP and agent-to-agent traffic in one data plane.
InfrastructureAFreshness: A★ 5.5Kgateway - 0.742score
ContextForge MCP Gateway
IBM
Open source registry and proxy that federates MCP, A2A and REST/gRPC APIs under central governance.
InfrastructureAFreshness: A★ 4.7Kgateway - 0.596score
LangSmith Deployment
LangChain
Framework-agnostic infrastructure for running long-running agents in production.
InfrastructureAFreshness: Ahosting - 0.585score
Orkes Conductor
Orkes
Platform to make AI agents and workflows durable, deterministic and explainable.
InfrastructureAFreshness: Adurable execution
Signals
- Stars
- 26,282
- Forks
- 2,679
- Open issues
- 222
- Last commit
- Oct 20, 2026 (10 days ago)
- Last release
- May 28, 2026 (5 months ago)
From GitHub (fetched Oct 24, 2026).
Details
- Version
- v1.0.1
- License
- Apache-2.0
- Repository
- github.com/a2aproject/A2A
- Website
- a2a-protocol.org/
- First seen
- Oct 24, 2026
- Last checked
- Oct 24, 2026
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Cite this page
Agent2Agent Protocol (A2A). Agent Mart. https://agentmart.dev/reference/agent2agent-protocol (last updated 2026-10-24)