Building a multitasking terminal
Crystl is a multitasking terminal for Claude Code (essentaily an AI interface) with a transparent cyrstaline design, branded features like gems, shards, and formations as well as a RPG themed chat interface for talking to multiple agents in a chatroom called Crystl Quest. It can run multiple AI agents in parallel, let them collaborate, and build small websites and apps in a matter of minutes.
Why I built this
I spend most of my day working with Claude Code — across client projects, my own products, and marketing work. The more I leaned into agentic coding, the more I needed to run multiple Claude sessions at the same time. But managing all those terminal windows was chaos. I’d lose track of which agent was waiting for approval, which one had finished, and which project I was even looking at.
I tried using multiple terminal tabs, split panes, and separate windows. None of it scaled. I wanted something purpose-built — a terminal that understood Claude Code and was designed around the way I actually work: many agents, many projects, all at once.
So I built Crystl. It’s a native macOS app written in Swift with Metal GPU rendering, designed from scratch for multi-agent orchestration.
What it does
Gems and shards
Crystl organizes work into gems (projects) and shards (terminal sessions). The Crystal Rail keeps every project one click away, even when you have dozens of sessions running. Each shard is a full terminal — you can use it for any command-line work, not just Claude Code.
Approval panels and notifications
The more agents you run, the harder it is to keep up. Crystl’s floating approval panels, notifications, and session colors let you spot what needs attention immediately — so no agent stalls waiting for you to notice.
Isolated shards
Run multiple Claude instances on the same repo without conflicts. Each isolated shard gets its own git worktree and branch, so agents can work in parallel without stepping on each other.
Conversation history
Every session is preserved. Scroll back through what Claude did, what was approved, and the full context of each conversation — across all your gems. Come back hours or days later and pick up where you left off.
Remote development
SSH into any machine and keep every Crystl feature working. Approval panels, file drag-and-drop, and click-to-open all flow through the tunnel automatically.
Starter templates and skills library
New gems launch with CLAUDE.md, AGENTS.md, skills, and MCP config pre-configured from your template library. Browse and import slash commands that teach Claude new tricks — code review, testing, deployment, and more.
Crystl Quest
Assemble a party of specialized agents — each with unique skills, the ability to coordinate in shared chat, and execute in parallel. Choose from archetypes like Wizard (UI/UX), Ranger (Frontend), Rogue (Backend), and more. Quest brings multi-agent collaboration to life with worktree isolation or shared directories.
See it in action
How it’s built
Crystl is a native macOS application built with Swift and Metal for GPU-accelerated terminal rendering. It uses macOS-specific features like the Keychain for secure API key storage and integrates deeply with Claude Code’s hook system for approval panels and notifications. It also has early support for OpenAI Codex.
- Native Swift app with Metal GPU rendering
- Free plan with 5 gems, 5 shards per gem, and core features
- Guild plan ($85/year) for unlimited gems, shards, prompt library, formations, and priority support
- Git worktree isolation for parallel agents
- MCP server configuration and API key management
- SSH remote development support
- macOS only