ACP - three different things share this acronym
Disambiguation (checked 2026-10-05)
“ACP” names at least two unrelated open protocols, and an earlier version of this note mixed them up.
| Name | Origin | Connects | Status (2026-10-05) |
|---|---|---|---|
| Agent Communication Protocol | IBM Research / BeeAI, launched March 2025 and donated to the Linux Foundation | agent to agent over REST | Merged into A2A; the merger was announced 2025-09-04 (LF AI & Data blog dated 2025-08-29). ACP no longer evolves separately; BeeAI agents move to A2A via adapters. See a2a-protocol and the historical A2A vs IBM ACP report. |
| Agent Client Protocol | Zed Industries, released 2025 (exact date not confirmed; Gemini CLI reported as an early partner); JetBrains joined as co-developer 2025-10-06 (per zed.dev blog) | code editor/IDE to coding agent (like LSP for agents); JSON-RPC over stdio locally, HTTP/WebSocket remotely | Active as of the sources fetched 2026-10-05. A JetBrains/Zed ACP Registry went live in late January 2026 (per heise; day unconfirmed) (agents listed include Claude Code, Codex CLI, Gemini CLI, GitHub Copilot, OpenCode, Qwen Code, Mistral Vibe). |
| acpx | OpenClaw project (github.com/openclaw/acpx), MIT licence | headless CLI client for Agent Client Protocol sessions: persistent sessions, one-shot runs, permissions, machine-readable output | Active as of 2026-10-05 (repo). Supports Pi, OpenClaw, Codex, Claude Code and custom ACP servers. |
So the “ACP” and “ACP-X” this note was created for (driving Codex or Claude Code sessions from Slack, Discord or a CLI) is the Agent Client Protocol plus the acpx client, not IBM’s agent-to-agent protocol. An earlier claim that ACP standardises agent-to-orchestrator communication for Kubernetes and chat platforms was not confirmed by the acpx or protocol documentation; the docs read do not define Kubernetes or Slack/Discord orchestration.
The 2026 agent-protocol landscape
- Tools and data: model-context-protocol (agent to tool), now under the agentic-ai-foundation.
- Agent to agent: a2a-protocol (absorbed IBM’s ACP; joined AAIF 2026-08-17 per that note).
- Editor to agent: Agent Client Protocol (this note).
- Project instructions: agents-md (AAIF-stewarded).
- Commerce: agent-payments-protocols.
Open items
- Zed’s exact release date for Agent Client Protocol (sources say August 2025) and the registry day (Jan 28 vs Jan 30 2026 in different sources) were not confirmed on a primary page.
- Whether acpx is used for Kubernetes/Slack orchestration in practice: not verified.
Sources (fetched 2026-10-05)
- https://lfaidata.foundation/communityblog/2025/08/29/acp-joins-forces-with-a2a-under-the-linux-foundations-lf-ai-data/
- https://agentclientprotocol.com/overview/introduction
- https://zed.dev/blog/jetbrains-on-acp
- https://www.heise.de/en/news/Integrate-AI-Agents-into-the-Editor-JetBrains-and-Zed-Release-ACP-Registry-11160709.html
- https://github.com/openclaw/acpx