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 rules/ashishpatill/tell-proof/tell-core-enginegit 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/rules/ashishpatill/tell-proof/tell-core-engine)<a href="https://agentmods.dev/rules/ashishpatill/tell-proof/tell-core-engine"><img src="https://agentmods.dev/badge/rules/ashishpatill/tell-proof/tell-core-engine.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 | $0.00000 | $0.00201 |
| Opus 5 | $0.00000 | $0.00101 |
| Sonnet 5 | $0.00000 | $0.00040 |
| Haiku 4.5 | $0.00000 | $0.00020 |
Grade A, and why
tell-core-engine 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 4d 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
Core engine rules
packages/schemais the contract source. Edit schemas first, export inferred TS types, and parse at boundaries.packages/corehas no LLM/API/model calls. Playwright is only for capture; tests use committed JSON.diagnose.tsmay import@tell/redesignonly for deterministic measured reconciliation data.- Detectors are pure:
(fingerprint, capture) => Finding[]. - Emit deterministic
factsandevidence; the taste layer judges final verdicts. - Keep all 14 detectors in
packages/core/src/detectorsunless a real split is needed. - Detector changes require golden coverage against
fixtures/reports/capture.json. - Use
@tell/core-engineersubagent for new schemas, capture, fingerprint, or detectors.
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.
- 4d ago First seen · 17 lines · 0 tokens per session scan A e11447d4d042
tell-core-engine is a cursor rule published in the GitHub repository ashishpatill/tell-proof (1 stars, last pushed 9d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 201 tokens. 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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