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 skills add paultyng/skill-issue --skill review-api-compatgit clone --depth 1 https://github.com/paultyng/skill-issueWrote 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/paultyng/skill-issue/review-api-compat)<a href="https://agentmods.dev/skills/paultyng/skill-issue/review-api-compat"><img src="https://agentmods.dev/badge/skills/paultyng/skill-issue/review-api-compat/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/paultyng/skill-issue/review-api-compat"><img src="https://agentmods.dev/badge/skills/paultyng/skill-issue/review-api-compat.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 | $0.00069 | $0.02185 |
| Opus 5.5 | $0.00028 | $0.00874 |
| Sonnet 5.5 | $0.00014 | $0.00437 |
| Haiku 4.5 | $0.00007 | $0.00218 |
Grade A, and why
review-api-compat 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 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.
Reads agent configuration directorieslowAgent snooping
.claude/, .codex/, .gemini/ hold keys, settings and other credentials a mod has no legitimate need for.
- Findings must cite probed evidence (`path:line`, grep output, command result), not pattern-matched suspicion. Per `~/.claude/rules/probe-not-assume.md`. Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.
How it starts
The opening of the file, as written. The whole thing — 167 lines — stays where its author put it; the contents beside it link to each section on GitHub.
API Compatibility Review
Structured review of API contract evolution. Detects breaking changes in protobuf services, OpenAPI specs, and (where applicable) GraphQL schemas; classifies them as wire-breaking, behavior-breaking, or policy-breaking; recommends remediation (deprecate-then-remove, version bump, new field).
Out of scope (defer to siblings):
- Internal Go API surface (function signatures, struct fields) —
review-codecovers this through SOLID/coupling lens - New field validation correctness —
review-code/review-security - Protobuf style / lint pass-fail (naming, comments, package layout) —
review-coderunsbuf lint
review-api-compat is the diff-aware counterpart: same proto/OpenAPI files, but compared against a base ref to catch what changed.
Workflow
1. Scope and explore
- Confirm scope with the user: changed files (PR or branch diff — the default), explicit paths to a previous version (e.g. a tag), or full codebase against
main. - Resolve scope. This skill is fundamentally diff-based:
- Default:
base_refismain(or the PR base). Compute changed files viagit diff --name-only --diff-filter=d <base>...HEAD. Filter to API spec files (see below). - PR: use
gh pr view <num> --json baseRefName -q .baseRefNamefor the base,gh pr diff <num> --name-onlyfor changed files. - Tag-vs-tag: user supplies
<from-tag>...<to-tag>; same diff machinery.
- Default:
- If invoked from review-all: receive
file_list,has_changes,base_ref,REVIEW_DIR, andpr_url. Ifhas_changesis false, exit early with status "no API spec changes in scope" — there is nothing to compare.
File classification:
- Protobuf:
*.protofiles; presence ofbuf.yaml/buf.gen.yaml/buf.lockconfirms a buf workspace. - OpenAPI:
openapi.yml,openapi.yaml,openapi.json,swagger.yml,swagger.yaml,swagger.json, files with top-levelopenapi:orswagger:keys. - GraphQL (lighter coverage):
*.graphql,*.gql, files withschema { ... }ortype Query { ... }.
What ships with it
1 file 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.
- 1mo ago First seen · 167 lines · 69 tokens per session scan A 255c27ae45da
review-api-compat is a skill published in the GitHub repository paultyng/skill-issue (8 stars, last pushed 4d ago), licensed MIT. It adds 69 tokens to every session and 2,185 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 1 finding (reads agent configuration directories). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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nodejs-backend
Node.js backend patterns: framework selection, layered architecture, TypeScript, validation, error handling, security, production deployment. Use when building REST APIs, Express/Fastify servers, microservices, or server-side TypeScript.
meta-reviewing-api-reviewing
Backend code review — injection and SSRF, boundary validation, object-level authorization, mass assignment and data exposure, error leakage, N+1 and unbounded queries. Use when a diff touches API routes or handlers, database access, auth middleware, or server code that reads files, starts processes or fetches URLs.
deep-review
Evidence-based deep code review rubric — severity + confidence findings across maintainability, correctness, security, performance, and testing. Push for ambitious structural simplification (code judo), not just local cleanup. Escalate hands-on triage to the code-reviewer agent.
gh-address-comments
Triage and address open GitHub PR review and conversation comments using the gh CLI. Use when the user wants to "address PR comments", "resolve review threads", or "respond to reviewers" on the current branch's pull request.