Borrowing it
Nothing to install: this file belongs to theMobiusStrip/agentpay-guard. 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/theMobiusStrip/agentpay-guard/main/.claude/skills/adversarial-review/SKILL.mdgit clone --depth 1 https://github.com/theMobiusStrip/agentpay-guardWrote 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/themobiusstrip/agentpay-guard/adversarial-review)<a href="https://agentmods.dev/skills/themobiusstrip/agentpay-guard/adversarial-review"><img src="https://agentmods.dev/badge/skills/themobiusstrip/agentpay-guard/adversarial-review/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/themobiusstrip/agentpay-guard/adversarial-review"><img src="https://agentmods.dev/badge/skills/themobiusstrip/agentpay-guard/adversarial-review.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 | $0.00143 | $0.00989 |
| Opus 5 | $0.00072 | $0.00495 |
| Sonnet 5 | $0.00029 | $0.00198 |
| Haiku 4.5 | $0.00014 | $0.00099 |
Grade A, and why
adversarial-review 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 9d 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 — 76 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Adversarial review — custody spine
The writing context does not get to grade its own work: it shares its own blind spots, which is exactly how a real overspend or fail-open slips through. The reviewer MUST be a separate subagent with fresh context.
Scope = the custody spine: the files in AGENTS.md → Security (the atomic
store, evaluate.ts, guard.ts, policy/*.ts, and the
x402-idempotency-middleware). If the diff doesn't touch those, say so and stop —
a broad code review is a different tool (/code-review).
1. Scope the diff
Collect the diff for the custody-spine files from the merge-base with the default branch to HEAD (or the working-tree diff if uncommitted). If none of those files changed, report "no custody-spine changes" and stop.
2. Independent review (Agent tool — a subagent that did NOT write this code)
Spawn a reviewer subagent. Give it: SECURITY.md, the AGENTS.md → Security
invariant table, the diff, and the files it touches. Instruct it to attack like a
staff custody/security engineer, not to confirm. For each hunk, find a concrete
way this change either widens an item in SECURITY.md's "Honest limitations" or
breaks a Security-table invariant. Hunt specifically for:
- Cap overspend / double-count in any interleaving — window-slide (pending reservation stops holding cap before terminal), settled spend dropped or double-counted, aggregate/per-payee accounting wrong.
- Early release —
releaseExpiredfreeing a still-settleable reservation; skew applied in the wrong direction;safeReleaseAtnot covering the signedvalidBefore. - Fail-open — a guard hook path that returns
void/undefined(⇒ allow) on error instead of{ abort: true }; an envelope/intent/dedup check bypassable. - Lifecycle mis-correlation —
onFailurereleasing a signed authorization's hold; ignoredtransition()CAS returns; nonce/FIFO correlation crossing concurrent identical payments. - Replay — the middleware keying on the client-supplied payment-identifier instead of the payer-signed authorization; a crash permanently stranding a payment; a stale worker overwriting a fresh grant.
- Honest-scope overclaim — a doc/comment claiming a guarantee the code doesn't provide, or relabeling arm A as "documented", or dropping a DrainBench fairness disclosure.
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.
- 9d ago First seen · 76 lines · 143 tokens per session scan A 9bf65decc07d
adversarial-review is a skill published in the GitHub repository theMobiusStrip/agentpay-guard (2 stars, last pushed 1mo ago), licensed MIT. It adds 143 tokens to every session and 989 once invoked, about $0.0007 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 2026-08-31.
Other skills, from other repositories
code-review
Paranoid architect review of code changes for bugs, security, missing tests, and undocumented assumptions. Works on local git diffs OR a GitHub pull request (e.g. owner/repo N). For PRs, can post findings as line-level review comments.
parallel-pr-review
Use when asked to "review the open PRs", review a batch or stack of pull requests, or run a recurring PR-review pass on a repo — especially with many PRs, stacked branches, conflicts, or security-sensitive changes. Covers grouping, fan-out to review subagents, verdict synthesis, and posting.
qa-review
QA review for code changes — test coverage analysis, edge case identification, test plan generation, regression detection, test health tracking over time.
security-review
Security audit for code changes and PRs — OWASP top 10, auth flows, data handling, secrets exposure, supply chain risks. Writes findings as actionable items.
review-readiness
PR readiness dashboard — tracks which reviews have been completed per branch and gates merge decisions. Shows code review, tests, security, QA, and linting status.
review-checklist
Pre-merge review checklist based on recurring AI reviewer feedback patterns.