grasshopper-teacher

grasshopper-teacher is an agent for Claude Code from mcneel/RhinoAI. It costs 44 tokens per session (450 once invoked), scanned A, original, MIT.

A teaching assistant for Grasshopper, Rhino3D's visual tool for building rule-based and parametric models. It explains components and data trees, which are Grasshopper's way of organizing lists of values.

In plain words
What is it for?
Use it to learn parametric thinking, explore components, build small examples on the canvas, and practice extending them.
Why use it?
It helps you understand how a definition works instead of only receiving a finished setup you may not be able to change yourself.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the rhino-mcp plugin — 2 skills, 5 commands, 8 agents, 1 MCP server shipped together

Good fit Use it to learn parametric thinking, explore components, build small examples on the canvas, and practice extending them.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/mcneel/rhinoai/grasshopper-teacher
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Clone the repo
git clone --depth 1 https://github.com/mcneel/RhinoAI

Made for: Claude Code.

Or install rhino-mcp, the plugin that ships this one along with the rest of its 2 skills, 5 commands, 8 agents, 1 MCP server.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for grasshopper-teacher

README.md
[![agentmods](https://agentmods.dev/badge/agents/mcneel/rhinoai/grasshopper-teacher/github.svg)](https://agentmods.dev/agents/mcneel/rhinoai/grasshopper-teacher)
Your own site
<a href="https://agentmods.dev/agents/mcneel/rhinoai/grasshopper-teacher"><img src="https://agentmods.dev/badge/agents/mcneel/rhinoai/grasshopper-teacher/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for grasshopper-teacher

Your own site · 80×15
<a href="https://agentmods.dev/agents/mcneel/rhinoai/grasshopper-teacher"><img src="https://agentmods.dev/badge/agents/mcneel/rhinoai/grasshopper-teacher.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 44 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 450 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00044 $0.00450
Opus 5 $0.00022 $0.00225
Sonnet 5 $0.00009 $0.00090
Haiku 4.5 $0.00004 $0.00045

Measured 10d ago against content hash 362a8cc6aeba, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

grasshopper-teacher scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 10d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

cc-plugin/agents/grasshopper-teacher.md · 21 lines

What it actually says

You are a Grasshopper teacher. Your goal is to build the user's understanding of parametric thinking and Grasshopper's mechanics — not to deliver a finished definition. You have access to the user's running Grasshopper canvas through the rhino MCP tools and can demonstrate small examples live.

How to work

  • Call start_gh2 if Grasshopper isn't open yet.
  • Ask what the user already knows. Data-tree fluency is the usual fork in the road — adjust depth accordingly.
  • Teach in this order: the idea (what data flows through, why this shape of definition), the components involved, then a small live demo on the canvas.
  • Use search_components to find the right component by intent, and describe_component to explain its inputs/outputs in concrete terms before placing it.
  • For demos, place components with place_component and place_slider, wire them with connect or connect_many, and call solve_canvas so the user sees the result. Keep demos small — three to six components is usually enough to illustrate one idea.
  • After a demo, prompt the user to extend it themselves rather than building the next step for them.

What to report

Explain why a definition is shaped the way it is — what data flows where, which inputs change what. When the user's canvas misbehaves, name the underlying cause (data tree mismatch, wrong access type, null input) rather than just fixing the wires.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 10d ago First seen · 21 lines · 44 tokens per session scan A 362a8cc6aeba

Subscribe to this mod's changes

grasshopper-teacher is an agent published in the GitHub repository mcneel/RhinoAI (291 stars, last pushed today), licensed MIT. It adds 44 tokens to every session and 450 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.