api-security-scan

api-security-scan is a skill for Claude Code, Codex from Quality-Max/free-qa-skills. It costs 53 tokens per session (588 once invoked), scanned A, original, Apache-2.0.

A read-only security review for REST and HTTP APIs, using an OpenAPI description or the code that defines the routes. It checks whether endpoints protect data and actions correctly.

In plain words
What is it for?
Use it to review API endpoints for authentication, authorization, rate limiting, sensitive data in URLs, and information leaked in errors, with findings tied to paths or file lines.
Why use it?
It helps find security gaps before release, such as missing login checks, weak permission checks, unlimited requests, or overly detailed error messages.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions Claude Code.

Good fit Use it to review API endpoints for authentication, authorization, rate limiting, sensitive…

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Install with agentmods
npx agentmods add skills/quality-max/free-qa-skills/api-security-scan
Install

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.

Any agent
npx skills add Quality-Max/free-qa-skills --skill api-security-scan
Clone the repo
git clone --depth 1 https://github.com/Quality-Max/free-qa-skills

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for api-security-scan

README.md
[![agentmods](https://agentmods.dev/badge/skills/quality-max/free-qa-skills/api-security-scan.svg)](https://agentmods.dev/skills/quality-max/free-qa-skills/api-security-scan)
Your own site
<a href="https://agentmods.dev/skills/quality-max/free-qa-skills/api-security-scan"><img src="https://agentmods.dev/badge/skills/quality-max/free-qa-skills/api-security-scan.svg" alt="Measured on agentmods" height="20"></a>
Per session 53 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 588 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00053 $0.00588
Opus 5 $0.00026 $0.00294
Sonnet 5 $0.00011 $0.00118
Haiku 4.5 $0.00005 $0.00059

Measured 6d ago against content hash f9f7f5711961, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

api-security-scan 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 6d 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.

skills/api-security-scan/SKILL.md · 63 lines

How it starts

The opening of the file, as written. The whole thing — 63 lines — stays where its author put it; the contents beside it link to each section on GitHub.

API Security Scan

Find the security holes in your API design before they ship. Read-only: it flags issues with file:line, it doesn't change your code.

Prerequisites

  • None. Pure Claude Code — reads your OpenAPI/Swagger spec or route/handler code directly, no MCP required.

Trigger

  • "Security review my API / OpenAPI spec"
  • "Check my endpoints for missing auth"
  • "API security scan"

Workflow

  1. Locate the API surface: an OpenAPI/Swagger file if present, otherwise the route definitions and handlers.
  2. Review each endpoint against the checks below; report path or file:line, severity, and the fix.

What to flag

Risk What to look for
Missing authentication Endpoints with no auth requirement that expose data or actions
Broken object-level auth (IDOR/BOLA) Resources fetched by ID with no ownership/authorization check
Missing function-level auth Admin/privileged operations reachable by normal users
No rate limiting Auth, search, or expensive endpoints with no throttling (brute-force / DoS)
Verbose errors Stack traces, SQL, or internal details returned to clients
Sensitive data in URLs Tokens, passwords, or PII in query strings (logged everywhere)
Mass assignment Request bodies bound to models without an allowlist of fields
CORS misconfig Wildcard origin combined with credentials
Missing input validation Body/query/path params accepted without schema/type checks
No pagination limits List endpoints that can return unbounded result sets
Secrets in examples Real keys/tokens in spec examples or sample requests
  1. Output a severity-ranked report:
## API Security Scan

**2 high, 1 medium**

### HIGH
- GET /users/{id} — no ownership check; any authenticated user can read any
  record (BOLA). Enforce that the caller owns or may access {id}.
- POST /login — no rate limiting; vulnerable to credential brute-force. Add
  per-IP/per-account throttling and lockout.

### MEDIUM
- GET /search — returns full stack traces on error. Return a generic message;
  log details server-side.

Read the full file on GitHub · 63 lines

Changes

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.

  1. 6d ago First seen · 63 lines · 53 tokens per session scan A f9f7f5711961

Subscribe to this mod's changes

api-security-scan is a skill published in the GitHub repository Quality-Max/free-qa-skills (10 stars, last pushed 13d ago), licensed Apache-2.0. It adds 53 tokens to every session and 588 once invoked, about $0.0003 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.

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