Atelier
Mac app for running parallel Claude Code agents in isolated git worktrees
Overview
A local-first Mac app for running many Claude Code agents at once. Each agent works in its own git worktree, so parallel tasks never collide, and one native window holds the agents, real terminal tabs, and a browser pane for the app being built. Currently in private preview.
Atelier doesn't reimplement the agent. It spawns the user's installed claude CLI headless and streams its JSON output, so new models, tools, and fixes arrive with each CLI update and it runs on the user's own Claude login. What Atelier adds is the layer around it: supervising many agents, isolating their files, rewinding mistakes, and extending the app with plugins. There's no server and no database, so code and data stay on the Mac.
Features
- Parallel Claude Code agents, each in a git worktree Atelier creates and cleans up.
- Rewind that rolls back both the transcript and the files, using hidden git snapshot objects.
- Real terminal tabs and a browser pane on the OS webview, opened beside the agents.
- Tasks board with one-click dispatch, plus notifications when an agent finishes or needs an answer.
- Local MCP server that lets agents call tools provided by the app and its plugins.
- On-device voice dictation with Whisper on the Mac GPU, no cloud API.
- Thirteen plugins, including Mermaid diagrams, a prompt library, test autorun, and a lint pass over every diff, each toggled on or off.
Highlights
- Thin native layer: a Rust and tokio core supervises many long-running claude processes with no Node runtime in the backend. The core has no Tauri dependency, so it's unit-tested on its own.
- Small footprint: Tauri draws the UI through the macOS webview instead of bundling Chromium. 18 MB installed and a 9 MB download on Apple silicon.
- The MCP server (axum) binds to 127.0.0.1 with a token per session.
- State is JSON files written atomically plus a JSONL event journal, and secrets stay in the OS keychain.