api-security-testing

api-security-testing is a skill for Claude Code from sickn33/agentic-awesome-skills. It costs 30 tokens per session (1,250 once invoked), scanned A, original, MIT.

A workflow for testing the security of REST and GraphQL APIs. It covers authentication, which verifies identity, authorization, which controls access, rate limits, input checks, and related weaknesses.

In plain words
What is it for?
Use it to assess API keys, JWTs, OAuth2 flows, token expiry, refresh tokens, rate limiting, input validation, and endpoint access controls.
Why use it?
An API may accept invalid credentials, expose data to the wrong user, or handle abusive requests poorly. This workflow breaks security checks into discovery, authentication, authorization, and other testing stages.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the agentic-awesome-skills plugin — 257 skills shipped together

Good fit Use it to assess API keys, JWTs, OAuth2 flows, token expiry, refresh tokens, rate limiting, input validation, and endpoint access controls.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/sickn33/agentic-awesome-skills/api-security-testing
About the project

AAS Core is a local control plane for coding agents that lets them search a large catalogue of skills, choose a stack, validate it, and create a reproducible plan. It is used to assemble and review agent workflows through its CLI, local MCP server, catalogue, plugins, and Workbench. The catalogue add-ons provide the skills, plugins, bundles, and workflows that AAS Core helps agents select and validate.

sickn33/agentic-awesome-skills · 48,465 stars · on GitHub · aaskills.tech

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 sickn33/agentic-awesome-skills --skill api-security-testing
Clone the repo
git clone --depth 1 https://github.com/sickn33/agentic-awesome-skills

Made for: Claude Code.

Or install agentic-awesome-skills, the plugin that ships this one along with the rest of its 257 skills.

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-testing

README.md
[![agentmods](https://agentmods.dev/badge/skills/sickn33/agentic-awesome-skills/api-security-testing/github.svg)](https://agentmods.dev/skills/sickn33/agentic-awesome-skills/api-security-testing)
Your own site
<a href="https://agentmods.dev/skills/sickn33/agentic-awesome-skills/api-security-testing"><img src="https://agentmods.dev/badge/skills/sickn33/agentic-awesome-skills/api-security-testing/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.

agentmods 80×15 button for api-security-testing

Your own site · 80×15
<a href="https://agentmods.dev/skills/sickn33/agentic-awesome-skills/api-security-testing"><img src="https://agentmods.dev/badge/skills/sickn33/agentic-awesome-skills/api-security-testing.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 30 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,250 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. Third-party audits
  • Socket warn 15 Oct 2026
  • Snyk pass 15 Oct 2026
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00030 $0.01250
Opus 5.5 $0.00012 $0.00500
Sonnet 5.5 $0.00006 $0.00250
Haiku 4.5 $0.00003 $0.00125

Measured 10d ago against content hash d8e3baf73f67, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

api-security-testing 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 10d 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.

Origin

Copies of this mod

8 near-identical copies found in the catalogue:

plugins/agentic-awesome-skills-claude/skills/api-security-testing/SKILL.md · 195 lines

How it starts

The opening of the file, as written. The whole thing — 195 lines — stays where its author put it; the contents beside it link to each section on GitHub.

⚠️ AUTHORIZED USE ONLY This skill is for educational purposes or authorized security assessments only. You must have explicit, written permission from the system owner before using this tool. Misuse of this tool is illegal and strictly prohibited.

Mandatory confirmation gate Before running any command that probes, exploits, changes, persists on, extracts data from, or attempts credential access against a target:

  1. Ask the user to state the exact target URL, IP, account, or resource.
  2. Ask the user to confirm written authorization and the permitted scope.
  3. Show the exact command(s) and explain their expected effect.
  4. Wait for explicit confirmation in the current conversation.

Without that confirmation, remain read-only and provide defensive guidance only. Prefer a sandbox, disposable VM, or controlled lab.

API Security Testing Workflow

Overview

Specialized workflow for testing REST and GraphQL API security including authentication, authorization, rate limiting, input validation, and API-specific vulnerabilities.

When to Use This Workflow

Use this workflow when:

  • Testing REST API security
  • Assessing GraphQL endpoints
  • Validating API authentication
  • Testing API rate limiting
  • Bug bounty API testing

Scope and evidence

Select approved phases and test accounts; do not dispatch every listed skill automatically. Use owned fixtures for destructive methods, injections, brute-force, resource exhaustion and deep/complex GraphQL requests. Define request, concurrency, byte and duration limits, stop conditions and cleanup before testing. Keep third-party systems and real customer data out of tests. Public schemas, missing headers and an HTTP success response alone do not prove an authorization flaw or exploitable limit bypass. Record untested endpoints and observed impact instead of checking “all endpoints tested” by assumption.

Workflow Phases

Phase 1: API Discovery

Skills to Invoke
  • api-fuzzing-bug-bounty - API fuzzing
  • scanning-tools - API scanning

Read the full file on GitHub · 195 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. 10d ago Changed · +18 lines d8e3baf73f67
  2. 1mo ago First seen · 177 lines · 30 tokens per session scan A 5eb0a027aa11

Subscribe to this mod's changes

api-security-testing is a skill published in the GitHub repository sickn33/agentic-awesome-skills (48,465 stars, last pushed yesterday), licensed MIT. It adds 30 tokens to every session and 1,250 once invoked, about $0.0001 per session on Opus 5.5. 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 2026-09-05.