Crystal Alternative: Run Claude Code and Codex Agents in Parallel
Crystal is deprecated: its repository says "Crystal (formerly a multi-session AI code assistant manager) has been deprecated and replaced by Nimbalyst. Deprecated: February 2026." So the question is not whether to move, but where your parallel Claude Code and Codex sessions should run next. This page compares Crystal with Foxpit, says plainly where Crystal or Nimbalyst is the better pick, and gives a four-step move.
Crystal in short
Crystal is a desktop app that runs several agent sessions in separate git worktrees so you can test and compare approaches side by side. Its description: "Run multiple Codex and Claude Code AI sessions in parallel git worktrees. Test, compare approaches & manage AI-assisted development workflows in one desktop app." (github.com/stravu/crystal)
- Interface: one desktop app. Since 0.3.0 a session can also hold multiple agent and terminal panels.
- Operating systems: macOS, Windows and Linux. Install notes cover macOS (Homebrew cask), 0.3.4 added Windows build requirements, and 0.2.0 forced GTK 3 on Linux.
- Agents: Claude Code and Codex. Codex support arrived in 0.3.0.
- Git worktrees: yes, that is the core of the design: one session per worktree, so two attempts do not touch the same files.
- Price and licence: MIT open source. No paid plan price is stated on the pages we checked.
- Latest release: v0.3.5, 26 February 2026 (releases).
The status, in the project's own words: "Crystal (formerly a multi-session AI code assistant manager) has been deprecated and replaced by Nimbalyst. Deprecated: February 2026." The same text adds: "You may continue to use Crystal but it will not be updated in the future." The replacement is linked from the README as nimbalyst.com.
The README says you may keep using it and the source stays readable. What you lose is the future, meaning fixes for new agent versions, new panels and new integrations.
Foxpit vs Crystal at a glance
| Feature | Crystal | Foxpit |
|---|---|---|
| Interface | Desktop app with session panels | Desktop app with a 3D office, rooms and a terminal grid |
| Operating systems | macOS, Windows, Linux | Windows 10/11 (x64), macOS on Apple Silicon, Linux (AppImage) |
| Agents | Claude Code, Codex | Claude Code, Codex CLI, OpenCode, Google Antigravity, built-in Foxpit engine |
| Git worktrees | Yes, one per session | Optional per-agent worktrees |
| Shared memory across agents | Not stated on its site | Yes: one project memory in .foxpit/memory, plain markdown |
| Lead agent that splits work | Not stated on its site | Yes: Fox splits a goal into task cards and hands them to teammates |
| Price / licence | MIT, no paid price stated | 3-day free trial, no card; Pro $5 first month, then $12 a month |
| Status | Deprecated February 2026, replaced by Nimbalyst | Active |
When Crystal is the better choice
Crystal has real strengths, and there are still good reasons to pick it or its successor:
- You want to compare two attempts of the same task. Two sessions in two worktrees, side by side, is exactly what the app was built for. The 0.3.4 "merge and archive" button closes the loop in one action (release notes).
- You want code you can keep. It is MIT licensed and on GitHub. If you only need the worktree-per-session model and nothing else, you can fork it and keep it alive yourself.
- You already have it working. The README says "You may continue to use Crystal but it will not be updated in the future." An app that does its job today does not have to be removed today.
- You want to follow the official successor. Nimbalyst is the replacement named by the project, and Crystal 0.3.4 added a button that opens Nimbalyst with worktree filter support. Treat it as a serious option: read nimbalyst.com and judge it on its own pages, because this article does not cover its features.
When Foxpit fits better
Foxpit is a desktop app that runs Claude Code, Codex, OpenCode and Antigravity as one team, with one room per project.
- Agents share what they learned. Crystal's sessions are parallel but separate. In Foxpit a new session on any agent reads the same project memory, so the decision made in one worktree is visible in the next.
- A lead agent divides the work. Fox breaks a goal into task cards with checklists, assigns them across seats and collects the result, instead of deciding by hand which seat gets which task.
- Long runs need less attention. Approval requests arrive as desktop notifications, and when Claude Code hits its 5-hour limit Fox parks the turn and sends "continue" at the reset.
Moving from Crystal to Foxpit
- Install Foxpit from Getting Started and start the 3-day trial. No card is needed.
- Leave the agent CLIs alone. Claude Code and Codex stay installed and logged in; Foxpit starts them in real terminals rather than replacing them.
- Add the repository as a room. A room is a project with its own team. Your existing branches are already in the repo, so nothing has to be exported.
- Open a worktree per agent before you run two agents at once, then move your open tasks into task cards and let Fox assign them.
Frequently asked questions
Is Crystal still maintained?
No. The repository says "Crystal ... has been deprecated and replaced by Nimbalyst. Deprecated: February 2026." and adds "You may continue to use Crystal but it will not be updated in the future." The last release listed is v0.3.5 from 26 February 2026.
What is Nimbalyst?
Nimbalyst is the replacement Crystal's repository names, and Crystal 0.3.4 added a button that opens Nimbalyst with worktree filter support. Nimbalyst's own features are outside the scope of this page, so check nimbalyst.com before you decide.
Can I keep my Crystal sessions in Foxpit?
Foxpit has no Crystal importer. Add the repository as a room and start the agents there; the branches and commits Crystal created in its worktrees stay in the same git repository, so the work itself is not stranded.
Related: Alternatives and comparison and What an AI coding agent orchestrator does.
Parallel agents are easier when they remember the same project.