ruler

The best way to get AI coding agents to solve hard problems in complex codebases.

(Crystal is now Nimbalyst) Run multiple Codex and Claude Code AI sessions in parallel git worktrees. Test, compare approaches & manage AI-assisted development workflows in one desktop app.

Spec-driven development (SDD) for your team's workflow. Kiro style commands that enforce structured requirements→design→tasks workflow and steering, transforming how you build with AI. Support Claude Code, Codex, Opencode, Cursor, Github Copilot, Gemini CLI and Windsurf.

Run Claude Code, Gemini, Codex — or any coding agent — in a clean, isolated sandbox with sensitive data redaction and observability baked in.