mcp-crewd-rs MCP server

mcp-crewd-rs

crewd is a cell fabric daemon for AI agents: it lets one AI session (Claude Code, Codex CLI, or any MCP client) spawn, coordinate and message other AI worker sessions — cells — through a single MCP server. Rust, one static binary per component, no network listener: everything runs over a local Unix socket.

Part of the mcp-*-rs family of Rust MCP servers.

┌────────────┐  MCP stdio   ┌──────┐   UDS (NDJSON)   ┌───────┐  spawns   ┌─────────────────┐
│ Claude Code│─────────────▶│ crew │─────────────────▶│ crewd │──────────▶│ engine processes│
│ / Codex CLI│  cell_* tools│ shim │  0600 socket     │daemon │           │ claude / codex  │
└────────────┘              └──────┘                  └───────┘           │ / pi workers    │
                                                                          └─────────────────┘

Components

MCP tools

Mounted per-cell via crew mcp:

cellsendtask, cellstatus, cellresult, cellcancel, celllist

• Fabric — cell_spawn (launch a worker cell: engine + profile + task),

(ask ticket + long-poll reply), cellreply, cellbroadcast, cell_inbox

• Bus — cellsend (fire-and-forget), cellask / cell_await

Worker cells get the same shim with --worker-mode, which hides the spawn surface (no uncontrolled nested fan-out).

Engines

Claude profiles select where the engine gets its credentials. max (the default) uses the host's own Claude credentials and needs no extra config. Additional profiles route the engine to an Anthropic-compatible endpoint, reading that profile's bearer token from keysenvpath (never from crewd.toml, argv or logs); the built-in ones are defined in the engine-claude adapter.

A cell's identity is its working directory: the spawned engine loads whatever CLAUDE.md, .mcp.json, memory and skills live in the cwd you pass to cell_spawn. One daemon can therefore serve several "personas" by spawning cells in different project roots.

Install

Prebuilt binaries (recommended) — download the archive for your platform from the latest release and extract; it contains crewd, crew and the shim/ directory:

tar xzf mcp-crewd-rs-x86_64-unknown-linux-gnu.tar.gz
install -m755 mcp-crewd-rs-*/crewd mcp-crewd-rs-*/crew ~/.local/bin/

Prebuilt targets (Linux + Android): x8664-unknown-linux-gnu, x8664-unknown-linux-musl, aarch64-unknown-linux-gnu, aarch64-unknown-linux-musl (edge / ARM), aarch64-linux-android (Termux).

Shortened. The full README is on GitHub.