Crystal was a desktop application for running multiple Codex and Claude Code sessions in parallel Git worktrees and comparing their coding work, but it was deprecated in February 2026 and replaced by Nimbalyst. It was intended for developers managing parallel AI-assisted development sessions. The catalogue contains instructions related to the former Crystal workflow.
Borrowing it
Nothing to install: this file belongs to stravu/crystal. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/stravu/crystal/main/CLAUDE.mdgit clone --depth 1 https://github.com/stravu/crystalWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/stravu/crystal/claude-md)<a href="https://agentmods.dev/instructions/stravu/crystal/claude-md"><img src="https://agentmods.dev/badge/instructions/stravu/crystal/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/stravu/crystal/claude-md"><img src="https://agentmods.dev/badge/instructions/stravu/crystal/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.06391 | $0.06391 |
| Opus 5.5 | $0.02556 | $0.02556 |
| Sonnet 5.5 | $0.01278 | $0.01278 |
| Haiku 4.5 | $0.00639 | $0.00639 |
Grade A, and why
crystal CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 522 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Crystal - Multi-Session Claude Code Manager
Created by Stravu
Project Overview
Crystal is a fully-implemented Electron desktop application for managing multiple AI code assistant instances (Claude Code and Codex) against a single directory using git worktrees. It provides a streamlined interface for running parallel AI assistant sessions with different approaches to the same problem.
References
Use these reference pages for more information:
- How to invoke Claude Code through the command line as an SDK: https://docs.anthropic.com/en/docs/claude-code/sdk
- How to run multiple Claude Code instances with Git Worktrees: https://docs.anthropic.com/en/docs/claude-code/tutorials#run-parallel-claude-code-sessions-with-git-worktrees
- Adding New CLI Tools: Guide for extending Crystal to support additional CLI tools beyond Claude Code
- Implementing New CLI Agents: Step-by-step instructions for adding new CLI agent tools with code examples and best practices
- Codex Configuration: Configuration guide for Codex CLI integration
Implementation Status: ✅ COMPLETE
All core features have been successfully implemented with significant enhancements beyond the original requirements.
✅ Implemented Features
Core Session Management
- Multi-session support: Run multiple Claude Code instances simultaneously
- Session templates: Create single or multiple sessions with numbered templates
- Session persistence: SQLite database for persistent sessions across restarts
- Session archiving: Archive sessions instead of permanent deletion
- Conversation continuation: Resume conversations with full history context
- Real-time status tracking: initializing, running, waiting, stopped, error
- Automatic session naming: AI-powered session name generation based on prompts
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 2mo ago First seen · 522 lines · 6,391 tokens per session scan A e00c294ed105
crystal CLAUDE.md is an instructions file published in the GitHub repository stravu/crystal (3,127 stars, last pushed 8mo ago), licensed MIT. It adds 6,391 tokens to every session, about $0.0256 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
crystal CLAUDE.md compared with instructions from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| crystal CLAUDE.mdstravu/crystal | Instructions file | 3.1k | 8mo ago | MIT | A | 6,391 | Claude Code |
| vscode buildNext.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 9,719 | GitHub Copilot |
| next.js AGENTS.mdvercel/next.js | Instructions file | 143k | today | MIT | A | 7,461 | Codex, OpenCode |
| langchain AGENTS.mdlangchain-ai/langchain | Instructions file | 149k | yesterday | MIT | A | 4,680 | Codex, OpenCode |
| vscode oss-third-party-notices.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 5,516 | GitHub Copilot |
| vscode copilot-instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 3,093 | GitHub Copilot |
| deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness | Instructions file | 274k | 2d ago | MIT | A | 4,313 | Codex, OpenCode |