Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add ondrej-svec/heart-of-gold-toolkit/plugin install marvinWrote 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/compound)<a href="https://agentmods.dev/skills/ondrej-svec/heart-of-gold-toolkit/compound"><img src="https://agentmods.dev/badge/skills/ondrej-svec/heart-of-gold-toolkit/compound/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/compound"><img src="https://agentmods.dev/badge/skills/ondrej-svec/heart-of-gold-toolkit/compound.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00078 | $0.02079 |
| Opus 5 | $0.00039 | $0.01040 |
| Sonnet 5 | $0.00016 | $0.00416 |
| Haiku 4.5 | $0.00008 | $0.00208 |
Grade A, and why
compound 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.
How it starts
The opening of the file, as written. The whole thing — 235 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Compound
Capture knowledge while context is fresh. Solutions, context docs, learnings — whatever you just discovered, structure it so it's findable and useful next time.
Boundaries
This skill MAY: read code/docs for context, write knowledge documents (solutions, context docs, learnings), update CLAUDE.md. This skill MAY NOT: edit application code, run tests, deploy, fix bugs. Knowledge capture only.
Common Rationalizations
| Shortcut | Why It Fails | The Cost |
|---|---|---|
| "Skip duplicate check — I'll write a new doc" | Parallel docs drift and eventually contradict | Knowledge drift → wrong fix applied next time |
| "Skip frontmatter — it's just metadata" | Frontmatter IS the search index. Without it, the solution is unfindable. | Captured but never surfaced → wasted effort |
| "Good enough — I'll refine later" | You won't. Context is freshest NOW. | Incomplete doc → next person can't reproduce the fix |
| "Too trivial to document" | The "trivial" fix that took 30 minutes will take someone else 30 minutes too | Repeated debugging of known problems |
Phase 0: Detect What to Capture
Entry: User invoked /compound — possibly after a fix, with a topic, or with no context.
Auto-detect capture type:
| Context | Capture Type | Output Location |
|---|---|---|
| Just fixed a bug, resolved an error | Solution | docs/solutions/{domain}/{topic}.md |
| Need to create/update AI context | Context doc | CLAUDE.md, ${CLAUDE_PLUGIN_ROOT}/knowledge/{topic}.md, or docs/ |
| Discovered a pattern or principle | Learning | CLAUDE.md or memory files |
If invoked after a fix: Scan conversation for what broke, what was investigated, what fixed it.
If invoked with a topic (e.g., /compound auth token refresh): Use as hint.
If unclear: Use AskUserQuestion with:
- question: "What knowledge do you want to capture?"
- header: "Type"
- options:
- label: "Solution", description: "Problem → root cause → fix → prevention (for docs/solutions/)"
- label: "Context doc", description: "AI context, onboarding, or decision record"
- label: "Learning", description: "Pattern, preference, or principle for CLAUDE.md or memory"
- multiSelect: false
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.
- 11d ago First seen · 235 lines · 78 tokens per session scan A 20153053b88d
compound is a skill published in the GitHub repository ondrej-svec/heart-of-gold-toolkit (19 stars, last pushed 22d ago), licensed MIT. It adds 78 tokens to every session and 2,079 once invoked, about $0.0004 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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