Fractal

Build using Architecture, not lines of Code

Fractal decomposes your application into Architecture Design Patterns, allowing you to build apps that AI agents can work with even when they grow large. Use an order of magnitude less tokens, enforcing architecture best practices and clean code, and building in a fraction of the time of a stock coding agent.

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The work board for one change: what it involves, the risks with the lines of code behind them, the plan's steps, and the modules the change reaches
The board, live while the change runs. A question waits for you on the right; the plan stops there until you answer.

The app first, then the change

Every view starts from your app's domains, so you see where a change sits before you read a line of it. The same board is on your phone: answer its questions from anywhere.

The whole app as a graph of domains, each box a domain and each line the references between two of them
The whole app, by domain.
The graph narrowed to the change: the modules it edits and reaches, gold where it writes
Only what the change reaches.
One domain in context: its modules, what uses it and what it uses, with counts of the references
One domain, with what uses it.

A hosted engine, with your hands

The engine runs on our servers and is never shipped. Everything that needs a key or runs your code goes back to your machine, through the agent you already use.

On your machine

  • Every model call goes to your own Claude Code, on your Claude subscription (claude -p). Our servers never hold a model key, and models are never on our bill.
  • Type checks and tests run on your machine, in a copy of your repo, sandboxed if you ask.
  • The finished change is applied to your repo only on your word, with a patch to undo it.

On our servers

  • The engine: the index, the domains, the plan, the checks.
  • The files your client sends for a job, by content hash. They are kept for that job only, 24 hours at most, and deleted when it ends. Never logged, never used for anything else.
  • Your account, your team's seats and your billing (through Stripe).

What we see and keep, exactly

Pricing

Freewhile Fractal is in preview; then $49 per user per month

  • One seat for each person who runs jobs. On your own, you are a team of one.
  • The owner invites people by email; they join with their own sign-in.
  • Add or remove seats at any time, prorated by Stripe, once billing starts.
  • Models run on your own Claude subscription, never through us.
Add it to Claude Code

Install

Fractal is a Claude Code plugin. Its client runs on your machine (Node 20 or later; macOS, Linux, Windows): it carries the engine's model calls to your Claude Code and runs your checks. The engine stays with us.

  1. Add the plugin (in Claude Code)
    /plugin marketplace add macleodlabs-ai/fractal-plugin
    /plugin install fractal@fractal
  2. Connect it to your account (opens a page to sign in with GitHub or email)
    /fractal:connect
  3. Ask for a change, or map a repo
    /fractal:edit <the change, in words>
    /fractal:scan