Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/briiirussell/cybersecurity-skillsnpx agentmods add rules/briiirussell/cybersecurity-skills/api-auditWrote 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/briiirussell/cybersecurity-skills/api-audit)<a href="https://agentmods.dev/rules/briiirussell/cybersecurity-skills/api-audit"><img src="https://agentmods.dev/badge/rules/briiirussell/cybersecurity-skills/api-audit/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/rules/briiirussell/cybersecurity-skills/api-audit"><img src="https://agentmods.dev/badge/rules/briiirussell/cybersecurity-skills/api-audit.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 | $0.00098 | $0.06168 |
| Opus 5.5 | $0.00039 | $0.02467 |
| Sonnet 5.5 | $0.00020 | $0.01234 |
| Haiku 4.5 | $0.00010 | $0.00617 |
Grade A, and why
api-audit scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured today.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
curl -s -D- -o/dev/null https://TEST-HOST/api/orders/$A_ORDER -H "authorization: Bearer $A_TOKEN" How it starts
The opening of the file, as written. The whole thing — 312 lines — stays where its author put it; the contents beside it link to each section on GitHub.
API Audit — REST / GraphQL / RPC Security Review
Perform a systematic security audit of API endpoints against the OWASP API Security Top 10 (2023). Distinct from owasp-audit — that's category-driven over a whole codebase, this is surface-driven over the API contract.
Use owasp-audit for the codebase as a whole. Use this when you need a focused pass over every endpoint with API-specific bypass patterns. They cross-reference each other where categories overlap.
Cross-references:
owasp-audit— the codebase-wide, category-driven audit; shares this release's verification, coverage, severity and findings machineryweb-pentest"Combined white-box + black-box mode" — pair this source-side audit with live testing of a running instancebusiness-logic-testing— invariant and race-condition testing of API flows (double-spend, TOCTOU on/transfer, coupon/quota races, out-of-order state machines). Hand off multi-step or concurrency-dependent flows there; this skill covers per-endpoint authz and misconfigurationfinding-triage— consumes thefindings.jsonthis skill emits
Authorization
Audit only APIs the user owns or has given you written permission to test; source review needs nothing more. For any live request, confirm the target is a test or staging instance, or that you have explicit authorization for production, and keep requests non-destructive: no writes to real tenants' data, no load. See Boundaries.
Workflow
Run in order. Do not skip to the checklist.
- Scope — auth model, tenancy, sensitive resources, run profile (full vs. diff).
- Recon / inventory — enumerate every entry surface and write the coverage ledger (
coverage.json). See references/recon-and-coverage.md. - Checks — walk the API1–API10 checklist per surface, recording each check in its coverage unit.
- Verify every finding — a per-candidate refutation pass that assigns one verdict:
confirmed|needs_validation|rejected. See references/verification.md. No finding reaches the report unverified. - Coverage critic — before writing anything, look for surfaces nobody mapped, parallel paths nobody checked, and unjustified exclusions.
- findings.json — write and validate the machine-readable findings file. The prose report is rendered from it; prose never changes a verdict, severity, or demonstrated impact.
- Report — render from the validated JSON and coverage ledger.
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.
- today Changed · +135 lines 9585cfaecfee
- 1mo ago First seen · 177 lines · 98 tokens per session scan A 01959aa8802b
api-audit is a cursor rule published in the GitHub repository briiirussell/cybersecurity-skills (435 stars, last pushed today), licensed MIT. It adds 98 tokens to every session and 6,168 once invoked, about $0.0004 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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