Borrowing it
Nothing to install: this file belongs to QuarkOS/Cairn. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/QuarkOS/Cairn/main/.cursor/skills/verify-cairn/SKILL.mdgit clone --depth 1 https://github.com/QuarkOS/CairnWrote 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/quarkos/cairn/verify-cairn)<a href="https://agentmods.dev/skills/quarkos/cairn/verify-cairn"><img src="https://agentmods.dev/badge/skills/quarkos/cairn/verify-cairn.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 | $0.00055 | $0.01818 |
| Opus 5 | $0.00028 | $0.00909 |
| Sonnet 5 | $0.00011 | $0.00364 |
| Haiku 4.5 | $0.00006 | $0.00182 |
Grade C, and why
verify-cairn scanned grade C with 2 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Downloads and executes remote codehighSupply chain
curl | sh runs whatever the server returns today, which is not necessarily what it returned when this was reviewed.
curl -sf "http://127.0.0.1:${PORT}/api/cairn" | node -e "const b=JSON.parse(require('fs').readFileSync(0,'utf8')); console.log(b.beliefs.filter(x=>x.current.attribute==='verify.marker').length)" Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
**Ready signal:** `curl -sf http://127.0.0.1:14721/api/cairn` returns JSON with `"kind":"recalled"`. The source is not reproduced here
No licence file
A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.
What ships with it
17 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- features/agent-canvas.md 982 B
- features/cli-init-recall.md 2.9 KB
- features/cursor-agent-plugin.md 2.8 KB
- features/desk-agent-api.md 1.2 KB
- features/desk-beliefs-table.md 2.0 KB
- features/http-api-assert-recall.md 1.2 KB
- features/README.md 1.6 KB
- features/retract-fact.md 1.9 KB
- scripts/cleanup.sh 897 B runs code
- scripts/doctor.sh 1.4 KB runs code
- scripts/drive-api-assert-recall.sh 2.9 KB runs code
- scripts/drive-canvas.sh 1.7 KB runs code
- scripts/drive-cli-init.sh 4.3 KB runs code
- scripts/drive-cli-recall.sh 1.4 KB runs code
- scripts/drive-cursor-plugin.sh 3.0 KB runs code
- scripts/drive-retract.sh 2.0 KB runs code
- scripts/launch.sh 1.7 KB runs code
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.
- 3d ago Changed · +2 lines 59f5fa5b2568
- 7d ago First seen · 166 lines · 55 tokens per session scan C fe8164563db6
verify-cairn is a skill published in the GitHub repository QuarkOS/Cairn (1 stars, last pushed 4d ago), with no licence file. It adds 55 tokens to every session and 1,818 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it C with 2 findings (downloads and executes remote code, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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