Run many agents on one repo without collisions
Send two agents at the same repo and they overwrite each other's work. Here each one gets its own branch and working directory, so they all go at once without the collisions.
Isolated shards use git worktrees to give each agent its own working copy of your repo on a separate branch. Send two agents at the same files and their live edits land in different directories; if both change the same lines, git surfaces that conflict when you integrate the branches.
Hover the shard bar's + and click the worktree row for a fresh branch off your default. Control-click it instead to fork from any branch, a release line or a teammate's work. Parked worktrees reopen any time from the branches button. New to worktrees? Our complete guide to git worktrees with Claude Code covers the manual commands too.
Use split view to watch both agents work side by side in one window. When a shard's work is done, merge it back to main with one click.
Need to script this? The crystl CLI exposes the same worktree spawn as crystl shard create --gem <name> --isolated, so orchestrator agents can fan parallel work out into siblings without the GUI in the loop.
Worktree isolation is not an OS sandbox. For Claude Code and Codex, crystl's hooks deny out-of-worktree paths named by Write, Edit, MultiEdit, NotebookEdit, and apply_patch. Arbitrary Bash writes are not generally path-confined; a narrower guard blocks commands that would destroy the shard's own worktree. Antigravity and generic terminal agents do not currently enforce hook denials. See the write guard documentation for the exact boundary.
Why it matters
Isolated git worktrees
Each isolated shard gets its own branch and working copy, keeping live in-repo edits separate until integration.
Hook-based write guard
Claude Code and Codex structured writes are checked before they run. Shell commands are only narrowly guarded against destroying the current worktree.
Zero-setup workspaces
crystl detects your package manager, installs dependencies, and symlinks .env files automatically.
Split view
Watch two agents work side by side in one window, like split-screen co-op. Compare output in real time.
One-click merge
Rebase onto main, fast-forward merge, and clean up the worktree, all in one click.
shard-tab badges
below a shard's tab, two small badges keep parallel work legible. ↑N counts an isolated shard's commits ready to merge; ⚑N flags files it touched outside its worktree, plus credential reads and writes. both are tinted to the shard's own color, and clicking either takes you straight to the action.
try it yourself
A free account and a download. macOS only, for now.
get startedgetting started guide →Frequently asked questions
- How many isolated shards can I run at once?
- As many as you like, on every plan including the free one. Run as many parallel sessions as your machine can handle.
- Do isolated shards work with any git repo?
- Yes. They use standard git worktrees, so any git repository works.
- What happens if two agents edit the same file?
- They can. Each edits a separate working copy on its own branch, so neither overwrites the other's live file. If they change the same lines, git surfaces a conflict when you integrate the branches.
- What if my project needs a custom setup step?
- Add a setupCommand to .crystl/project.json. crystl runs it after dependency installation.
- What happens to a shard's branch after merging?
- crystl cleans up the worktree and branch automatically after a successful merge.
Crystl's Book of Spells
Master crystl with a grimoire of powerful prompts. Summon heroes, assemble a party, revive shards, and complete epic quests.
open the book →More features
Gems & Shards
Gems, shards, and the crystal rail keep every project one click away.
just-ask control
Ask for what you need and your agent does the clicking: text staged for copying, a button that runs the command, a task added, work booked for tomorrow.
Floating Cards
See what every agent needs from you, the moment it needs it.
Agent Activity Panel
One live view of every agent across all your gems: who's working, who's idle, and where tokens are going.
Schedule Agents
Launch a fresh agent at a set time (once, daily, or weekdays). Pick the gem, agent, model, and prompt; crystl fires it on schedule.
Automation (Sequences)
Automate the work you keep doing by hand. Write the job down once and let a schedule, a file landing, or a watched URL run it for you.
Hero Shards
Summon a single hero as a shard (its own agent, model, and persona) without a quest party.
View Modes
Read a session as a terminal, as a conversation beside it, or as a conversation filling the window. The terminal keeps running either way.
History Navigator
Browse, jump through, and search every session: conversation and tool calls.
Token Tracking
Track token burn per shard, estimate turns left, and reclaim context window by disabling heavy plugins and skills.
Workbench
A slide-out task list in every project, backed by a WORKBENCH.md the agent reads and writes with you.
Markdown Editor
Render and edit any .md in a side panel. Toggle it from the workbench, and let agents open docs for you from the CLI.
Prompt Integration
Facet Inserts give you one-click access to saved prompts, commands, and shortcuts.
Agent File Editor
Create, edit, and manage CLAUDE.md, rules, skills, and agent config files with a block editor, file chooser, and project optimizer.
Project Optimizer
Scan your project for gaps in agent configuration (missing files, incomplete docs, oversized code, and setup issues) with one-click fixes.
Skills Library
Browse and import agentic skills that teach agents like Claude Code or Codex new tricks: code review, testing, deployment, and more.
cavrn terminal
The terminal as structured data: every turn, tool call, result, and table captured as agent-readable metadata. Drawn fast on the GPU with Metal.
Remote Development
Full crystl integration over SSH: approval cards, file relay, and click-to-open on remote machines.
Open Models
Run open models locally or hosted, orchestrate them with frontier agents, and cut token costs.
Agent Orchestration
One agent spawns, supervises, and merges the work of many: a control room for a team of coding agents.
crystl quest
Assemble a party of specialized agents. Each brings unique skills, coordinates in shared chat, and executes in parallel.
Screenshot Bar
Drag recent screenshots into the terminal. Spotlight-powered, always up to date.
Copy Bar
A one-click copy bar under the terminal. Agents stage text, you click Copy. Editable, up to 10 tabs, free.