Borrowing it
Nothing to install: this file belongs to ashishpatill/tell-proof. 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/ashishpatill/tell-proof/master/.cursor/skills/tell-capture-fingerprint/SKILL.mdgit clone --depth 1 https://github.com/ashishpatill/tell-proofWrote 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/ashishpatill/tell-proof/tell-capture-fingerprint)<a href="https://agentmods.dev/skills/ashishpatill/tell-proof/tell-capture-fingerprint"><img src="https://agentmods.dev/badge/skills/ashishpatill/tell-proof/tell-capture-fingerprint/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/ashishpatill/tell-proof/tell-capture-fingerprint"><img src="https://agentmods.dev/badge/skills/ashishpatill/tell-proof/tell-capture-fingerprint.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 | $0.00054 | $0.00562 |
| Opus 5.5 | $0.00022 | $0.00225 |
| Sonnet 5.5 | $0.00011 | $0.00112 |
| Haiku 4.5 | $0.00005 | $0.00056 |
Grade A, and why
tell-capture-fingerprint 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 1mo 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 — 64 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Tell capture and fingerprint
Scope
packages/core/src/capture/— Playwright capture of rendered UIpackages/core/src/fingerprint/— deterministic aggregation toDesignFingerprintpackages/core/src/scripts/capture-fixture.ts— regenerate fixture capturefixtures/reports/capture.json— committed offline capture artifact
Pipeline
- Navigate URL (or local route); wait for network idle
- Full-page screenshot → base64 PNG
- CDP/computed-style walk on curated selectors (~200 nodes max)
- Interactive probes for hover, focus-visible, disabled states
- DOM summary: headings, buttons, centered ratio, emoji in UI chrome
- Emit
CapturePayloadvalidated by@tell/schema
Fingerprint fields
Aggregate fonts, colors, shadows, radii, spacing, type scale, gradient detection, near-duplicate grays, focus-ring coverage, and state coverage. No network or LLM.
Full-page capture (stitched)
When a page is taller than one viewport or uses lazy/sticky stages:
- Prefer Playwright
fullPage: truescreenshot as the primary artifact - Scroll the document once before capture so lazy sections mount
- After fonts and sticky measurements settle, re-measure and capture again if the first pass clipped
- Keep the same URL and viewport width for before/after proof compares
- Never claim a stitched panorama if only the fold was captured — set
metahonestly
Rules
- Capture may use Playwright; unit tests must use committed JSON only
- Keep capture normalization stable between runs
- Any capture schema change requires updating committed
capture.json - Web diagnose subprocess uses
diagnose-url.ts; MCP usescaptureUrldirectly
Commands
pnpm dev:fixture # bland demo app on :3001
pnpm capture:fixture # regenerate capture.json
pnpm diagnose:fixture # full diagnose on fixture
pnpm test # fingerprint/detector golden tests
DoD
- Valid
CapturePayloadfor generic fixture - Fingerprint snapshot fields stable enough for detector golden tests
- Capture completes in demo time budget (< 8s on fixture)
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.
- 1mo ago First seen · 64 lines · 54 tokens per session scan A 1541ab37d5a7
tell-capture-fingerprint is a skill published in the GitHub repository ashishpatill/tell-proof (2 stars, last pushed 22d ago), licensed MIT. It adds 54 tokens to every session and 562 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-09-03.
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