Crystal

Crystal provided a way to run several Claude Code instances at the same time by leveraging git worktrees for isolation. The tool set up separate worktrees for each AI coding session, allowing users to keep parallel codebases distinct while sharing a common repository. It was packaged for macOS and reached a stable maturity level.

The workflow centered on creating a new worktree for each Claude Code instance, then launching the AI assistant within that isolated environment. This approach let developers switch between sessions without risking cross‑contamination of edits, and it integrated with standard git commands for committing and merging changes.

Although the project is now deprecated as of February 2026, the functionality remains available for those who continue to use it, with the developers recommending migration to the successor platform, Nimbalyst, which builds on the same concepts with additional features.