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 agentmods add skills/thettwe/nyann/check-prereqsnpx skills add thettwe/nyann --skill check-prereqsgit clone --depth 1 https://github.com/thettwe/nyannWrote 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/thettwe/nyann/check-prereqs)<a href="https://agentmods.dev/skills/thettwe/nyann/check-prereqs"><img src="https://agentmods.dev/badge/skills/thettwe/nyann/check-prereqs.svg" alt="Measured on agentmods" 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 | $0.00149 | $0.00506 |
| Opus 5 | $0.00075 | $0.00253 |
| Sonnet 5 | $0.00030 | $0.00101 |
| Haiku 4.5 | $0.00015 | $0.00051 |
Grade A, and why
check-prereqs 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 6d 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.
What it actually says
check-prereqs
Read-only environment survey. Never installs anything; never mutates the filesystem. Flow:
- Run
bin/check-prereqs.sh. Default output is a human-readable table showing every prereq nyann touches, classified as hard (nyann exits 1 without it) or soft (feature-gated skip). - If the user passes the word
json/ "machine-readable" / similar, add--jsonso output is structured for scripting. - Exit code from the script is the signal:
0→ all hard prereqs present. Soft misses are informational.1→ at least one hard prereq is missing. Tell the user explicitly that nyann cannot run yet, and point them at the install hint from the table.
What to do after
- Soft misses aren't blockers, but each gates a specific feature. Offer
to explain which feature needs which tool. Don't install anything on
the user's behalf — just read the
hintcolumn back and let them decide. - If the user asks "install these for me", decline politely — nyann
doesn't bulk-install system packages. Direct them to the copy-pasteable
install lines in the
hintcolumn.
When to hand off
- User asks "OK, now bootstrap this repo" → route to the
bootstrap-projectskill. - User asks "what does do in nyann?" → explain the feature(s) it gates (README has a table per soft dep).
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.
- 6d ago First seen · 46 lines · 149 tokens per session scan A fe0c21909807
check-prereqs is a skill published in the GitHub repository thettwe/nyann (6 stars, last pushed 7d ago), licensed MIT. It adds 149 tokens to every session and 506 once invoked, about $0.0007 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 2026-08-31.
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