Key takeaways
- Open-source MIT-licensed alternative to Conductor for multi-agent development
- Uses git worktrees to isolate parallel AI sessions, preventing code conflicts
- Supports both Claude Code and OpenAI Codex in the same workflow
FAQ
What is Crystal for Claude Code?
Crystal is an open-source macOS desktop app that lets developers run multiple Claude Code or Codex AI sessions in parallel using isolated git worktrees.
How much does Crystal cost?
Crystal is completely free and open-source under the MIT license.
Who makes Crystal?
Crystal is developed by Stravu, a software company focused on AI development tools.
Executive Summary
Crystal is an open-source desktop application that enables developers to run multiple Claude Code and Codex AI sessions simultaneously in isolated git worktrees. Built by Stravu, Crystal solves the parallelization problem that developers face when waiting for AI agents to complete tasks—instead of sequential work, developers can test multiple approaches concurrently and merge the best results.
| Attribute | Value |
|---|---|
| Company | Stravu |
| Founded | 2025 |
| Funding | Undisclosed |
| Employees | ~5-10 (estimated) |
| Headquarters | United States |
Product Overview
Crystal addresses a fundamental workflow limitation in AI-assisted development: waiting for agents to finish before starting new work. By leveraging git worktrees—a git feature that allows multiple working directories from a single repository—Crystal isolates each AI session in its own environment. Developers can launch multiple sessions with different prompts, compare the results, and selectively merge the best approaches back to main.
The application wraps both Claude Code (Anthropic's CLI agent) and OpenAI Codex, providing a unified interface for managing parallel AI development workflows. Each session gets its own worktree, history, and context, eliminating the risk of agents interfering with each other's changes.
Key Capabilities
| Capability | Description |
|---|---|
| Parallel Sessions | Run unlimited Claude Code or Codex sessions simultaneously |
| Git Worktrees | Each session operates in an isolated git worktree |
| Rich Output | Visual interface showing agent progress and outputs |
| Diff Viewer | Review all changes before merging to main |
| Run Scripts | Test code within Crystal before committing |
| Squash & Merge | Clean commit history when finalizing changes |
Product Surfaces
| Surface | Description | Availability |
|---|---|---|
| macOS App | Native desktop application | GA |
| Windows | Supported via build from source | Beta |
| Linux | AppImage available | Beta |
| Homebrew | brew install --cask stravu-crystal | GA |
Technical Architecture
Crystal is an Electron-based desktop application that orchestrates multiple CLI agent processes. When a developer creates a session, Crystal:
- Creates a new git worktree from the current branch
- Launches the selected AI agent (Claude Code or Codex) in that worktree
- Captures and displays the agent's output in real-time
- Tracks all changes and commits within the isolated worktree
- Provides diff viewing and selective merge capabilities
Key Technical Details
| Aspect | Detail |
|---|---|
| Deployment | Local desktop application |
| Model(s) | Claude Code (Anthropic), Codex (OpenAI) |
| Integrations | Git, GitHub, Amazon Bedrock (via Claude Code settings) |
| Open Source | Yes (MIT License) |
Strengths
- Zero cost barrier — Completely free and open-source under MIT license, with no premium tiers or hidden features
- True parallelization — Git worktree isolation means sessions never conflict, unlike running multiple terminals manually
- Model flexibility — Supports both Claude Code and Codex, allowing developers to compare approaches across providers
- Clean git history — Squash and rebase workflow produces clean commit history without merge conflicts
- Third-party deployment support — Works with Amazon Bedrock and other Claude Code deployment options
Cautions
- Agent dependency — Requires Claude Code or Codex to be separately installed and authenticated
- macOS-first — While cross-platform in theory, Windows/Linux require building from source and have less testing
- Disk space — Each worktree is a full copy of the repository, which can be expensive for large repos
- No cloud sync — Sessions and state are local-only; no team collaboration features
- Early-stage project — Active development may mean breaking changes between versions
Pricing & Licensing
| Tier | Price | Includes |
|---|---|---|
| Open Source | Free | All features |
Licensing model: MIT License (permissive open source)
Hidden costs: Users must pay for their own Claude Code or Codex subscriptions/API usage. Crystal itself adds no cost.
Competitive Positioning
Direct Competitors
| Competitor | Differentiation |
|---|---|
| Conductor | Crystal is free/open-source; Conductor is paid SaaS |
| Tembo | Tembo offers enterprise orchestration; Crystal is developer-focused |
| Maestro | Maestro focuses on autonomous long-running tasks; Crystal emphasizes comparison workflows |
When to Choose Crystal Over Alternatives
- Choose Crystal when: You want free, open-source multi-agent workflows with git worktree isolation
- Choose Conductor when: You need a polished commercial product with support
- Choose Tembo when: You need enterprise-scale agent orchestration with team features
- Choose Maestro when: You want autonomous long-running agent sessions with mobile monitoring
Ideal Customer Profile
Best fit:
- Individual developers using Claude Code or Codex
- Teams wanting to evaluate open-source multi-agent tools
- Developers who frequently compare different AI approaches
- macOS users comfortable with early-stage software
Poor fit:
- Enterprise teams needing collaboration and access control
- Windows/Linux users who can't build from source
- Developers who prefer fully autonomous agents over comparison workflows
Viability Assessment
| Factor | Assessment |
|---|---|
| Financial Health | N/A (open source) |
| Market Position | Challenger |
| Innovation Pace | Rapid |
| Community/Ecosystem | Growing |
| Long-term Outlook | Positive |
Crystal is backed by Stravu and has an active development community on Discord. As an open-source project, its longevity depends on community adoption and continued company sponsorship. The project is still early-stage but shows consistent releases and feature development.
Bottom Line
Crystal fills an important gap in the AI coding tools ecosystem as a free, open-source option for parallel agent development. Its git worktree approach is technically elegant and solves real workflow problems for developers who want to compare multiple AI approaches.
Recommended for: Individual developers and small teams using Claude Code or Codex who want to parallelize their AI-assisted development without paying for commercial tools.
Not recommended for: Enterprise teams needing collaboration features, or developers requiring polished cross-platform support.
Outlook: Crystal has strong fundamentals as a free alternative to Conductor. If Stravu continues development and the community grows, it could become the default open-source choice for multi-agent orchestration.
Research by Ry Walker Research • methodology