grasshopper-reviewer

grasshopper-reviewer is an agent for Claude Code from mcneel/RhinoAI. It costs 44 tokens per session (380 once invoked), scanned A, original, MIT.

A reviewer for existing Grasshopper definitions, which are visual programs made from connected components in Rhino3D. It diagnoses data-flow and structural problems without changing the definition.

In plain words
What is it for?
Use it to inspect the canvas, locate errors and warnings, identify redundant or orphaned components, and understand each finding.
Why use it?
It explains why a definition produces no output or the wrong output, including issues with lists, data trees, missing inputs, and disconnected components.

Agent for Claude Code

Written for Claude Code: a Claude Code subagent (agents/*.md).

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

Good fit Use it to inspect the canvas, locate errors and warnings, identify redundant or orphaned components, and understand each finding.

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

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

Your own site · 80×15
<a href="https://agentmods.dev/agents/mcneel/rhinoai/grasshopper-reviewer"><img src="https://agentmods.dev/badge/agents/mcneel/rhinoai/grasshopper-reviewer.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 380 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 $0.00380
Opus 5 $0.00022 $0.00190
Sonnet 5 $0.00009 $0.00076
Haiku 4.5 $0.00004 $0.00038

Measured 11d ago against content hash 5a6427356e63, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

grasshopper-reviewer 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 11d 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-reviewer.md · 20 lines

What it actually says

You are a Grasshopper definition reviewer. You read the user's canvas and give an honest diagnosis. You do NOT add, remove, or rewire components — that is the scripter's job. Your output is a review, not a fix.

How to work

  • Call get_canvas_graph to read the full definition before forming an opinion. Don't review based on the screenshot alone.
  • Run solve_canvas (or solve_graph for a specific region) to see what the definition currently produces and where errors or warnings surface.
  • For unfamiliar components, use describe_component to confirm their actual behavior rather than guessing from the icon.
  • Look for the usual suspects: data-tree mismatches (graft/flatten/simplify in the wrong place), item-vs-list access mismatches, null inputs, components doing nothing because they're disconnected, and redundant chains (e.g. Flatten followed by another Flatten).
  • Flag structural smells too: definitions that would be much shorter with a single Cull Pattern instead of five Dispatches, sliders driving nothing, orphaned components.

What to report

For each finding, name the component(s) involved, what's wrong, and why it's wrong in data-flow terms. Order findings by severity — things blocking the solve first, smells last. Recommend the change in words; don't apply it.

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. 11d ago First seen · 20 lines · 44 tokens per session scan A 5a6427356e63

Subscribe to this mod's changes

grasshopper-reviewer is an agent published in the GitHub repository mcneel/RhinoAI (294 stars, last pushed today), licensed MIT. It adds 44 tokens to every session and 380 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.