# Agent Communication Protocol vs Agent Connect Protocol (AGNTCY)

Both belong to the Protocols called ACP group on this map. The map lists them as complementary: sites and agents commonly implement both. They share the acronym ACP but sit at different steps and are unrelated. They answer different questions: Agent Communication Protocol is a step 6 (Coordinate) standard, Agent Connect Protocol (AGNTCY) step 5 (Act), so they are not substitutes.

[6 Coordinate](/category/coordinate/) [Agent Communication Protocol](/protocols/agent-communication-protocol/) · [5 Act](/category/act/) [Agent Connect Protocol (AGNTCY)](/protocols/agent-connect-protocol/)

|  | [Agent Communication Protocol](/protocols/agent-communication-protocol/) ACP | [Agent Connect Protocol (AGNTCY)](/protocols/agent-connect-protocol/) ACP |
| --- | --- | --- |
| Lifecycle step | 6 Coordinate: Talk to another agent | 5 Act: Do something for me |
| Answers | How did agents, applications, and people exchange multimodal REST messages before merging into A2A? | How does one agent (or an orchestrator) invoke and configure a remote agent it did not build, over a plain HTTP API? |
| Governed by | Formerly IBM BeeAI; archived, functionality merged into A2A under the Linux Foundation | AGNTCY project (Cisco donated AGNTCY to the Linux Foundation); the acp-spec GitHub repository was archived by its owner (the agntcy GitHub organization) on 2026-04-11 and is now read-only, while the broader AGNTCY project (49 repositories, most recently updated within hours of this check) remains active under Linux Foundation governance, with its discovery/identity work now centered on the 'dir' (Distributed Announce and Discovery) and OASF (Open Agentic Schema Framework) projects rather than acp-spec |
| Status (issuer's words) | "ACP is now part of A2A under the Linux Foundation" (repository banner) | Archived repository (2026-04-11) |
| Phase | deprecated | deprecated |
| Version | v1.0.3 (2025-08-21) | v0.2.3 (OpenAPI 3.1.1) (2025-05-23) |
| Form / transport | endpoint | endpoint |
| Found at | /agents | /agents/search |
| Adoption | unmeasured | unmeasured |
| Evidence | 4 verified, 1 reported | 4 verified, 1 reported |
| Primary use case | Let agents talk to other agents | Let agents talk to other agents |
| Last verified | 2026-10-19 (current) | 2026-10-19 (current) |
| Specification | [https://github.com/i-am-bee/acp](https://github.com/i-am-bee/acp) | [https://github.com/agntcy/acp-spec](https://github.com/agntcy/acp-spec) |

## When to use which

- Choose Agent Communication Protocol when your question is “How did agents, applications, and people exchange multimodal REST messages before merging into A2A?” and you accept its maturity: phase deprecated, adoption unmeasured. It is no longer maintained; prefer its successor.
- Choose Agent Connect Protocol (AGNTCY) when your question is “How does one agent (or an orchestrator) invoke and configure a remote agent it did not build, over a plain HTTP API?” and you accept its maturity: phase deprecated, adoption unmeasured. It is no longer maintained; prefer its successor.

Guidance is derived from the two records (question, phase, adoption, prerequisites, pairings), not from opinion. Each record's page carries its numbered references.

## Read the full articles

- [Agent Communication Protocol](/protocols/agent-communication-protocol/): How did agents, applications, and people exchange multimodal REST messages before merging into A2A?
- [Agent Connect Protocol (AGNTCY)](/protocols/agent-connect-protocol/): How does one agent (or an orchestrator) invoke and configure a remote agent it did not build, over a plain HTTP API?

Ask the MCP server to compare any two: the compare-protocols prompt, or get on both ids. [Connect](/connect/).

[agent-communication-protocol.json](/data/protocols/agent-communication-protocol.json) · [agent-connect-protocol.json](/data/protocols/agent-connect-protocol.json) · [Markdown](/compare/agent-communication-protocol-vs-agent-connect-protocol/index.md)