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/cofin/flow/security-auditornpx skills add cofin/flow --skill security-auditorgit clone --depth 1 https://github.com/cofin/flowWhat 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 | $0.00043 | $0.00336 |
| Opus 5 | $0.00022 | $0.00168 |
| Sonnet 5 | $0.00009 | $0.00067 |
| Haiku 4.5 | $0.00004 | $0.00034 |
Grade A, and why
security-auditor 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 2d 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
Security Auditor
Review security-sensitive code for realistic exploit paths and proportionate defenses. Use directly or as a security-focused review subagent.
Workflow
- Load the security persona and threat checklist below.
- Inspect the actual entry points, trust boundaries, data flows, and deployed controls.
- Apply every relevant threat category and report evidence-backed findings.
Guardrails
Follow the persona boundaries. Do not inflate theoretical weaknesses, omit realistic attack preconditions, or provide exploit instructions beyond what is needed to explain and remediate the risk.
Output
For each finding, state the category, calibrated severity, realistic attack vector, evidence, and fix. Briefly acknowledge reviewed categories with no finding.
Validation
Confirm severity follows exploitability and impact, and each fix addresses the described attack path.
Example
Report an object-level authorization gap with the attacker precondition, affected resource, severity, and server-side ownership check required.
References
- Persona — security role, severity model, and boundaries.
- Threat checklist — OWASP-oriented evidence checks.
- Critic stance — optional adversarial framing.
What ships with it
3 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.
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.
- 2d ago First seen · 61 lines · 43 tokens per session scan A 71e5a6b396d5
security-auditor is a skill published in the GitHub repository cofin/flow (15 stars, last pushed 3d ago), licensed Apache-2.0. It adds 43 tokens to every session and 336 once invoked, about $0.0002 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 2026-08-30.
Other skills, from other repositories
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Use when executing implementation plans with independent tasks in the current session.
write-documentation
Use when writing or substantially rewriting human-facing prose: documentation, README, guides, blog posts, emails, Slack messages, PR descriptions, release notes, or any text a human will read. Not for code comments, commit messages, or agent-to-agent communication.
document-release
Use when implementation on a branch is complete and it is about to be merged or PR'd — or when finishing-a-development-branch reaches its docs-audit gate — and after code changes are committed, to ensure all project documentation accurately reflects shipped code. Covers README, ARCHITECTURE, CONTRIBUTING, CHANGELOG…
finishing-a-development-branch
Use when implementation is complete, all tests pass, and you need to decide how to integrate the work - guides completion of development work by presenting structured options for merge, PR, or cleanup.
systematic-debugging
Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.
writing-plans
Use when you have a spec or requirements for a multi-step task, before touching code.