prepare-prompt

prepare-prompt is a skill for Claude Code, Codex from w1ne/kernelCAD-web. It costs 33 tokens per session (1,244 once invoked), scanned A, original, MIT.

A prompt-planning guide that turns a vague request for a physical object into a written design brief before any geometry is made. The brief records what the reference shows, including scale and unresolved questions.

In plain words
What is it for?
Use it when creating a 3D object from text, photos, or both, especially when scale, material, hidden surfaces, or other important details are uncertain.
Why use it?
It prevents later modelling steps from relying on unclear assumptions. The brief becomes the shared reference for the rest of the build.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/w1ne/kernelcad-web/prepare-prompt
Any agent
npx skills add w1ne/kernelCAD-web --skill prepare-prompt
Clone the repo
git clone --depth 1 https://github.com/w1ne/kernelCAD-web

Made for: Claude Code, Codex.

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 prepare-prompt

README.md
[![agentmods](https://agentmods.dev/badge/skills/w1ne/kernelcad-web/prepare-prompt.svg)](https://agentmods.dev/skills/w1ne/kernelcad-web/prepare-prompt)
Your own site
<a href="https://agentmods.dev/skills/w1ne/kernelcad-web/prepare-prompt"><img src="https://agentmods.dev/badge/skills/w1ne/kernelcad-web/prepare-prompt.svg" alt="Measured on agentmods" height="20"></a>
Per session 33 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,244 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00033 $0.01244
Opus 5 $0.00016 $0.00622
Sonnet 5 $0.00007 $0.00249
Haiku 4.5 $0.00003 $0.00124

Measured 5d ago against content hash 4baf255e62b7, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

prepare-prompt 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 5d 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.

src/agent/skills/kernelcad-from-reference/prepare-prompt/SKILL.md · 138 lines

How it starts

The opening of the file, as written. The whole thing — 138 lines — stays where its author put it; the contents beside it link to each section on GitHub.

prepare-prompt

Purpose

A vague ask — "a wayfarer-style frame", "that bottle", "make the same one" — produces vague geometry. This sub-skill produces a Real Object Brief: a structured, numbered record of everything the reference communicates before any tool call touches the kernel.

The brief is written as a // Real Object Brief block at the top of the .kcad.ts file, before any param() or geometry. It is the source of truth for the entire build. Every downstream sub-skill reads from it.

Inputs

  • The user's ask (text, photo path, or both).
  • The reference photo(s) — can be one image showing one view, or several showing different angles. More views = fewer hidden-side guesses.

Output

A filled-in // Real Object Brief comment block, plus a list of open questions if any critical fact (scale, material, hidden side) cannot be inferred.

The Real Object Brief format

Required sections, in this order:

// Real Object Brief
// Artifact: <human name> — <one-line description of what it is>.
//   Reference: <relative path to the photo>.
// Scale: millimetres. <key dimension 1: name ~N mm>, <key dimension 2: name ~N mm>,
//   <overall bounding box estimate>.
// Visible facts (from reference photo):
//   - <Numbered or bulleted. Each item is a distinct visual element.>
//   - <Separate form (silhouette) from surface (color, texture, gloss).>
//   - <Include relative positions: "A is above B", "C spans the full width".>
// Hidden-side inference:
//   - <What must exist that the photo does not show: case back, internal walls,
//     fastener counterbores, mounting tabs, wire paths.>
//   - <Infer from category: a pocket watch has a case-band, a mug has a handle
//     undercut, a USB dongle has a PCB pocket.>
// Validation focus:
//   - <The 3–5 visual cues you will check against each rendered view.>
//   - <Name the view (front, top, right, iso) + what to check in it.>

Scale discipline

If the reference photo has a known scale object (a hand, a coin, packaging dimensions), record it:

Read the full file on GitHub · 138 lines

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. 5d ago First seen · 138 lines · 33 tokens per session scan A 4baf255e62b7

Subscribe to this mod's changes

prepare-prompt is a skill published in the GitHub repository w1ne/kernelCAD-web (18 stars, last pushed 7d ago), licensed MIT. It adds 33 tokens to every session and 1,244 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.

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