<!-- Canonical: https://www.agentlist.io/systems/a2a -->

# A2A Protocol

[08 agent-communication](https://www.agentlist.io/categories/agent-communication)/[A2A Project](https://www.agentlist.io/ai/a2a-project)/ACTIVE/aka Agent2Agent, A2A

A2A (Agent2Agent) is the open protocol for cross-vendor agent communication — Google-originated, now governed at the Linux Foundation — standardizing Agent Cards for capability discovery plus task-based messaging between agents.

-   [Agent-to-agent protocol](https://www.agentlist.io/capabilities/a2a)
-   [API-native](https://www.agentlist.io/capabilities/api-native)

SEC.01

## What it does

-   01Agent Cards for capability discovery
-   02Task lifecycle and artifacts
-   03Streaming updates
-   04Vendor-neutral governance (Linux Foundation)
-   05Composes with MCP

SEC.02

## Who it's for

Exposing an agent to third-party callers, or wiring agents from different vendors into one workflow without bespoke adapters.

PRICING

## Pricing

Open protocol (free). List prices as checked against the vendor's pricing page on 2026-09-25; plans change often, so confirm before deciding.

caveat · before you adopt

The spec is still moving — most real deployments are intra-org, and several big vendors ship partial support.

ALT

## Other agent communication platforms (12)

[OpenScout / Scout OpenScout · agent-communication cli/api · local · Free (OSS), local](https://www.agentlist.io/systems/scout)

[AGNTCY AGNTCY · agent-communication api · local/cloud · Free (OSS, Apache-2.0)](https://www.agentlist.io/systems/agntcy)

[Agent Network Protocol Community / OSS · agent-communication api · local/cloud · Open protocol (free)](https://www.agentlist.io/systems/anp)

[NANDA NANDA (MIT Media Lab) · agent-communication api · local/cloud · Free (research project)](https://www.agentlist.io/systems/nanda)

[BeeAI IBM · agent-communication api/cli · local/cloud · Free (OSS, Apache-2.0)](https://www.agentlist.io/systems/beeai)

[CrewAI CrewAI · agent-communication api/cli · local/cloud · Free OSS core; CrewAI Enterprise paid (verify)](https://www.agentlist.io/systems/crewai)

[Microsoft Agent Framework Microsoft · agent-communication api · local/cloud · Free OSS (MIT); Azure hosting via Foundry](https://www.agentlist.io/systems/agent-framework)

[LangGraph LangChain · agent-communication api · local/cloud · Free OSS; LangGraph Platform paid tiers](https://www.agentlist.io/systems/langgraph)

[MetaGPT DeepWisdom · agent-communication api/cli · local/cloud · Free OSS; MGX hosted product paid (verify)](https://www.agentlist.io/systems/metagpt)

[CAMEL CAMEL-AI · agent-communication api · local/cloud · Free (OSS, Apache-2.0)](https://www.agentlist.io/systems/camel)

[Agency Swarm VRSEN · agent-communication api · local/cloud · Free (OSS)](https://www.agentlist.io/systems/agency-swarm)

[OpenAI Agents SDK OpenAI · agent-communication api · local/cloud · Free (OSS SDK); model usage metered](https://www.agentlist.io/systems/openai-agents-sdk)

VS

## Head-to-head (1)

-   [→A2A Protocol vs AGNTCY](https://www.agentlist.io/compare/a2a-vs-agntcy)

FAQ

## Frequently asked

### What is A2A Protocol?

A2A (Agent2Agent) is the open protocol for cross-vendor agent communication — Google-originated, now governed at the Linux Foundation — standardizing Agent Cards for capability discovery plus task-based messaging between agents.

### Who is A2A Protocol for?

Exposing an agent to third-party callers, or wiring agents from different vendors into one workflow without bespoke adapters.

### How much does A2A Protocol cost?

Open protocol (free). List prices as checked against the vendor's pricing page on 2026-09-25; plans change often, so confirm before deciding.

### Does A2A Protocol run locally or in the cloud?

A2A Protocol runs locally on your machine and in the vendor's cloud. Its interfaces are an API or protocol.

### What are alternatives to A2A Protocol?

Other agent communication platform entries in the catalog: OpenScout / Scout, AGNTCY, Agent Network Protocol, NANDA, BeeAI, CrewAI, Microsoft Agent Framework, LangGraph, MetaGPT, CAMEL, Agency Swarm, OpenAI Agents SDK. Different categories solve the same problem differently — see the Agent communication & collaboration category page for tradeoffs.

### What should I know before adopting A2A Protocol?

The spec is still moving — most real deployments are intra-org, and several big vendors ship partial support.

Spec sheet

**Name**: A2A Protocol

**Vendor**: [A2A Project](https://www.agentlist.io/ai/a2a-project)

**Category**: [Agent communication & collaboration](https://www.agentlist.io/categories/agent-communication)

**Interfaces**: api

**Hosting**: local · cloud

**Pricing**: Open protocol (free)

**Status**: actively maintained

**Speaks**: -   [A2A (Agent2Agent)](https://www.agentlist.io/transports/a2a)

**Aliases**: Agent2Agent, A2A

**Record ID**: `sys://a2a-project/a2a`

**Verified**: [2026-09-25](https://www.agentlist.io/changelog)

Sources

-   [↗ a2a-protocol.org](https://a2a-protocol.org/)
-   [↗ github.com/a2aproject/A2A](https://github.com/a2aproject/A2A)

Catalog entries are editorial records, not paid placements or endorsements. Pricing and status are approximate as of the seed date.

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Source: [A2A Protocol — AGENT-COMMS by A2A Project | agentlist.io](https://www.agentlist.io/systems/a2a). This is the public page rendered as Markdown; interactive controls require the website.