The protocol that lets many AI agents from different vendors work in parallel on the same repository without stepping on each other. Path claims, inboxes, handoffs and signed events instead of guesswork — in plain files that git already understands. No server, no cloud, no telemetry.
Teams now run agents from several vendors at once: one writes code, another tests, a third documentation. Each has its own log and its own session memory. None of them knows what the others are doing right now — so they overwrite each other’s files, duplicate work and lose context at every handover.
MACP gives them a shared language and a shared memory: who holds what, who finished what, who handed what to whom. Recorded in the repository so it can be read in code review and checked after the fact.
.coord/Agent cards, claims, event log, inboxes, handoffs, decisions — plain YAML, JSONL and Markdown inside the repository. No daemon, no database, no central server.
The MACP server exposes 60+ typed coordination tools. The same server serves Claude Code, Codex, Gemini CLI, opencode, Warp and clients that do not exist yet. About 4k tokens instead of a 40k prompt.
A log entry carries the identity [agent:session:model] and an ed25519 signature. From the same log MACP rebuilds the workspace state at any past instant.
There is no central hub to scale. Agents talk to each other through files; every instance — including many sessions of the same model — has its own identity and its own key. Adding an agent means adding a card in .coord/agents/.
The cost of entry does not grow with the number of agents: MCP tools are shared and a per‑agent adapter weighs a few dozen tokens. While building MACP itself, agents from four vendors worked in parallel on one repository — without a single file ownership conflict.
▸ click the agent counter in the diagram above — and watch what happens to the log
The whole protocol lives inside the repository directory. No hosted service, no telemetry, no vendor account.
Agent identity on ed25519 keys the organisation keeps. Signed releases, SBOM, build provenance.
Adapters for local models — Ollama, llama.cpp, vLLM, LM Studio — for tasks that cannot leave the organisation’s network.
> Specification: handbook v1.0 (22 sections) as the single source of truth; reference implementation in TypeScript — seven packages, CLI, MCP server, terminal dashboard and a macOS app.
> Sovereignty Pack at release‑candidate stage (v1.12).
MACP is a standalone product, developed independently of Coord Control. It runs without it — in the terminal, with a text dashboard and a macOS app. Coord Control is the local operations layer on top of MACP workspaces: oversight, decision gates and the evidence pack. War Room was built entirely by agents working over MACP.
Delivery covers initialising .coord/ in the client’s repository, wiring adapters to the agents in use, and handing the team the handbook and the signing policy.
A way of binding the events of many agents into one verifiable evidence chain — signature, order, reproducibility.
Every protocol change is a signed entry: postmortem, proposal, vote, ratification. The history of the spec is itself an evidence chain.
The Coord Control patent application. MACP supplies the event layer on which that proof is built.
> The “MACP chain of custody” family remains in preparation — number and priority date will follow filing.
> Filing an application does not equal a grant of protection.