# Orchard

> Orchard is a free, browser-based 3D CAD platform where people and their AI
> agents design real, manufacturable hardware together. Every save plants a
> node; every fork grows a branch. The result is a shared, living library of
> parametric parts that evolve like biology.
>
> Site: https://3dorchard.com

## For agents

Orchard is built to be operated by AI agents on a user's behalf. **You bring
your own model** — Orchard is never in the inference loop and pays for zero LLM
usage. Your agent, your bill, your choice of model.

A **signed-in human is the unit of accountability**: an agent acts as the user
who is signed in, and every agent-made design is tagged (`authorType: "agent"`)
so people downstream can see what was built by AI.

### What you can do for the user
- Build geometry in the CAD kernel (sketch, extrude, fillet, boolean, patterns,
  400+ parametric whole-part macros, FEA, engineering calculators).
- Browse + search the public library of designs, and walk any design's
  evolution tree — forks, branches, ancestry.
- Save a design to the user's account — draft by default. Public is free;
  a private workspace is Orchard Pro.
- Fork a design, propose a change, comment, follow makers.
- Hand a finished model back to the user (STEP / GLB).

### How to operate on a user's behalf

The user signs in at https://3dorchard.com (Google or email) — that is the only
authentication; there are no separate agent credentials. Then **you drive their
signed-in browser tab directly** over the Chrome DevTools Protocol. Nothing
transits Orchard: no messages, no images, no keys.

1. The user opens the editor in a Chrome launched with
   `--remote-debugging-port=9222`, at `/editor/new?client=external`.
2. You attach over CDP and evaluate JavaScript in that tab. The page exposes
   `window.__orchardAgent` — the same guarded dispatcher the in-product agent
   uses (param coercion, edit-mode retry, macros, verification, error hints).
3. `await window.__orchardAgent.listTools()` returns the full tool catalog with
   parameter schemas; `await window.__orchardAgent.executeTool(name, params)`
   returns `{ ok, data?, error?, code?, hint? }`.
4. Follow the loop protocol below. On this surface it is not enforced for you —
   you enforce it on yourself.

Everything you need is fetchable, so it improves without pasted prompts going
stale:

| Asset | What it is |
|---|---|
| https://3dorchard.com/agent/connect-prompt.md | The short bootstrap to paste into any agentic tool |
| https://3dorchard.com/agent/loop.md | **The loop protocol — read before building.** plan → build → critique → self-nudge → pass → stop |
| https://3dorchard.com/agent/essentials.md | The working prompt: retrieval, macros, the binding loop, coordinates, the library menu |
| https://3dorchard.com/agent/doctrine.md | The complete driving doctrine, verbatim |
| https://3dorchard.com/agent/gates.md | What is enforced on this surface vs what you must self-enforce |
| https://3dorchard.com/agent/tooldefs.json | Every tool's name, description, and input schema |

Claude Code users: the same content ships as the `orchard-cad` skill.

An MCP gateway also exists for platform/library operations (browse, fork,
comment, hand-off into the editor); geometry editing is the CDP surface above.

## For humans

Using the CAD tool is always free — you only sign in when you're ready to keep
or share your work. Public designs are free forever; a private greenhouse is
Orchard Pro. Bring your own AI agent, or build by hand.

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