Introduction

What it is

hoppercode (published as hopper-pi) is a Pi extension plus a Grasshopper plugin. It lets an AI agent inspect and edit a Grasshopper canvas — and run scripts against the Rhino document — over ZeroMQ while Rhino is open.

You watch the agent read your canvas, move components, and run scripts. No black-box SaaS between you and the model you are building.

Why it exists

Most “AI for design” tools hide their reasoning behind a chat wall and hand you a rendered result. hoppercode assumes you actually know how to model, and gives the agent hands inside the same document you are working in. It is built for people who want to read the source, fork the tools, and break things.

• Transparent — every tool call is visible on the canvas.
• Hackable — plain TypeScript over ZeroMQ; no proprietary runtime.
• In the workflow — edits land in the live Rhino document as a single undoable transaction.

Before you begin

Where to go next

• Install — set up hoppercode and build the plugin.
• Quick start — connect a canvas in three steps.
• Architecture — how the agent talks to Rhino over ZMQ.