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

Transport — Agent wire protocols

# A2A (Agent2Agent)

Wire formats between agents, hosts, and tool servers. Cross-vendor agent wire: Agent Cards for discovery, task lifecycle and streaming updates. Google-originated, now Linux Foundation. [a2a-protocol.org ↗](https://a2a-protocol.org/)

Catalog entry: [A2A Protocol](https://www.agentlist.io/systems/a2a)

MIX

## Who speaks it

-   03[agent communication platforms](https://www.agentlist.io/categories/agent-communication)
-   01[bridge protocols](https://www.agentlist.io/categories/bridge)
-   01[agent services](https://www.agentlist.io/categories/agent-services)

BY

## Vendors (5)

-   [A2A Project](https://www.agentlist.io/ai/a2a-project)
-   [Community / OSS](https://www.agentlist.io/ai/community)
-   [Google](https://www.agentlist.io/ai/google)
-   [IBM](https://www.agentlist.io/ai/ibm)
-   [OpenScout](https://www.agentlist.io/ai/openscout)

MATRIX

## Agents on this wire (5)

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

[Instinct Community / OSS · bridge caution api · local · Free (OSS, MIT)](https://www.agentlist.io/systems/instinct)

[A2A Protocol A2A Project · agent-communication api · local/cloud · Open protocol (free)](https://www.agentlist.io/systems/a2a)

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

Extended matrix — 1 more

80/20 preview

TABLE

## Transport table

| Agent | Vendor | Category |
| --- | --- | --- |
| OpenScout / ScoutOpenScout / Scout is a local-first broker that lets addressable agents (Claude Code, Codex, Cursor) send and ask across harnesses on one mesh. | OpenScout | agent-communication |
| InstinctInstinct is a self-learning memory MCP server for coding agents — it observes repeated patterns, scores them by confidence, and promotes mature ones into suggestions it exports back to Claude Code, Cursor, Windsurf, Codex, and CLAUDE.md. | Community / OSS | bridge |
| A2A ProtocolA2A (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. | A2A Project | agent-communication |
| BeeAIBeeAI is IBM's open-source agent platform — run, compose, and observe agents locally or on a cluster, with ACP/A2A-style interop and a web UI for non-technical operators. | IBM | agent-communication |

KIND

## More agent wire protocols

-   [ACP](https://www.agentlist.io/transports/acp)
-   [AG-UI](https://www.agentlist.io/transports/ag-ui)
-   [AGNTCY / SLIM](https://www.agentlist.io/transports/agntcy-slim)
-   [AITP](https://www.agentlist.io/transports/aitp)
-   [ANP (Agent Network Protocol)](https://www.agentlist.io/transports/anp)
-   [MCP (Model Context Protocol)](https://www.agentlist.io/transports/mcp)

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