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.
npx skills add ondrej-svec/heart-of-gold-toolkit --skill scaffoldgit clone --depth 1 https://github.com/ondrej-svec/heart-of-gold-toolkitWrote 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.
[](https://agentmods.dev/skills/ondrej-svec/heart-of-gold-toolkit/scaffold)<a href="https://agentmods.dev/skills/ondrej-svec/heart-of-gold-toolkit/scaffold"><img src="https://agentmods.dev/badge/skills/ondrej-svec/heart-of-gold-toolkit/scaffold/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.
<a href="https://agentmods.dev/skills/ondrej-svec/heart-of-gold-toolkit/scaffold"><img src="https://agentmods.dev/badge/skills/ondrej-svec/heart-of-gold-toolkit/scaffold.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00051 | $0.01426 |
| Opus 5 | $0.00026 | $0.00713 |
| Sonnet 5 | $0.00010 | $0.00285 |
| Haiku 4.5 | $0.00005 | $0.00143 |
Grade A, and why
scaffold 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 12d 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.
How it starts
The opening of the file, as written. The whole thing — 187 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Scaffold
Prepare a project for development. Creates directories, configs, and installs dependencies — never source or test files.
Boundaries
This skill MAY: create directories, config files, install dependencies, set up tooling. This skill MAY NOT: create source files (*.ts, *.js, *.py, etc.), create test files, write implementation code, write test code.
NEVER create source or test files. Structure and configuration only.
Common Rationalizations
| Shortcut | Why It Fails | The Cost |
|---|---|---|
| "Create a starter file — just a skeleton" | Skeletons become the implementation. Test writers then test the skeleton, not real behavior | Weak tests that pass with stubs |
| "Skip dependency install — implementer can do it" | Missing deps cause confusing errors downstream | Wasted time debugging missing imports |
| "Use default configs — they'll customize later" | Default configs often conflict with project conventions | Config drift → inconsistent behavior |
Step 1: Read Architecture Doc
If $ARCH_PATH is set (pipeline mode):
- Read the architecture doc at
$ARCH_PATH - Extract: dependencies, file structure, external services
- Announce: "Reading architecture: [filename]."
If no env var (standalone mode):
- Use AskUserQuestion (header: "Project", question: "What project are you setting up? Provide an architecture doc path, or describe what you're building.")
- If they provide a path, read it
- If they describe it, gather: language/framework, dependencies, project type
Exit: Know what directories, dependencies, and configs are needed.
Step 2: Assess Project State
Determine if this is greenfield or brownfield:
# Check for existing project indicators
ls package.json pyproject.toml Cargo.toml go.mod 2>/dev/null
ls -d src/ lib/ app/ 2>/dev/null
- Greenfield: No project manifest or source directories exist
- Brownfield: Project exists — verify paths, note discrepancies with architecture doc
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.
- 12d ago First seen · 187 lines · 51 tokens per session scan A b805c7154227
scaffold is a skill published in the GitHub repository ondrej-svec/heart-of-gold-toolkit (19 stars, last pushed 22d ago), licensed MIT. It adds 51 tokens to every session and 1,426 once invoked, about $0.0003 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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