I built a desktop app for Meta's Muse Code CLI, and the billing is the whole story

Description and use

Helicon is an open‑source desktop and web client that uses the official Muse Code SDK to communicate with the agent via the Muse Session Protocol, preserving subscription billing and simplifying installation by bundling Node.

Problem

Meta’s Muse Code CLI is terminal‑only and lacks a Windows binary, forcing users to rely on competitors for a desktop experience and risking billing confusion when wrapping the CLI.

Outcome

Helicon delivers a native desktop experience for Muse Code on Windows and other platforms, preserves subscription billing, eliminates terminal scraping bugs, and simplifies installation by bundling Node.

Workflow

• 1. Install Helicon (auto‑signed installer with bundled Node).
• 2. Helicon spawns a "muse serve" daemon per workspace via the SDK.
• 3. The daemon communicates with Muse over the Muse Session Protocol (MSP).
• 4. Approvals, diffs, and session history are received as structured protocol events, not parsed terminal output.
• 5. The UI displays projects, threads, approvals, and a cost view based on API rates.
• 6. On Windows, Helicon runs "wsl -d Ubuntu -- muse serve" and translates paths between Windows and WSL.
• 7. Users interact via a React UI that works both as a Tauri desktop app and a web app.
• 8. Helicon’s bundled Node runtime is isolated from the system PATH to avoid interference with user shells.

Evidence

Muse Code subscriptions only bill through Muse's own harness. If you point a generic OpenAI-compatible client at the API, you are on pay-as-you-go rates instead.

Source

The daemon runs natively on Windows, and when it needs the agent it runs: wsl -d Ubuntu -- muse serve

Source