---
title: "What is ACP, the Agent Client Protocol?"
url: https://helicon.sh/glossary/acp
description: "ACP is a general protocol that lets editors talk to any conforming coding agent. How it differs from a Muse Code specific protocol, and what gets lost in the bridge."
updated: 2026-09-19
site: Helicon
---

# What is ACP, the Agent Client Protocol?

The Agent Client Protocol is a general interface that lets an editor drive any conforming coding agent, so Zed or a JetBrains IDE can use several agents through one integration. Bridges expose Muse Code over ACP. Anything ACP has no vocabulary for, such as Muse Code specific usage reporting, has to be approximated.

## The tradeoff

|  | General protocol (ACP) | Native protocol (MSP) |
| --- | --- | --- |
| Agents supported | Many | Muse Code |
| Editor integration | Write once for all agents | Per agent |
| Feature fidelity | Lowest common denominator | Everything the agent exposes |
| New agent capability | Waits for the protocol to grow | Available when the SDK has it |

## When each is right

If you want one editor panel that can drive whichever agent you are paying for this month, a general protocol is exactly right. If you want a client that surfaces one agent completely, including its approval modes and its usage reporting, a native protocol client is the one that can do it.

## Frequently asked questions

### Does Helicon use ACP?

No. Helicon is a Muse Code Session Protocol client and talks to muse serve directly.

### Can I use an ACP editor and Helicon together?

Yes. They share the same CLI and login, and sessions are discoverable either way.

### Is one protocol better?

They answer different questions. Breadth across agents, or depth on one.

## Related

- [the Muse Code Session Protocol](https://helicon.sh/glossary/msp): MSP is the JSON-RPC protocol that applications use to drive a Muse Code session over stdio, instead of parsing terminal output. What it carries and why it matters.
- [Zed with ACP](https://helicon.sh/compare/zed-acp): Running Muse Code inside Zed through an Agent Client Protocol bridge, compared with a standalone Muse Code desktop app. Editor native versus session native.
- [JetBrains IDEs](https://helicon.sh/compare/jetbrains-acp): Muse Code inside IntelliJ, PyCharm, GoLand or WebStorm through an Agent Client Protocol plugin, compared with a standalone Muse Code desktop app.

---

Helicon is a free, MIT licensed, unofficial community client for Meta's Muse Code CLI. Not made, sponsored or endorsed by Meta. Source: https://helicon.sh/. Machine readable index: https://helicon.sh/llms.txt