api-security-testing
Lets your agent test API security. It checks if protections against access and attacks are working well.
What it does
This tool helps test the security of APIs (interfaces that allow programs to communicate), checking if they are protected against unauthorized access, data manipulation, and other attacks. It analyzes how the API handles passwords, permissions, usage limits, and submitted data.
When to use it
- ✓When you need to check if an API is secure against hackers.
- ✓When developing an API and wanting to ensure it has no security flaws.
- ✓To test if the limits on how often someone can use an API are working correctly.
Example of what to ask your AI
“I want to test the security of the API at 'https://example.com/api'. I have written authorization for this.”
Want more? Open the sections below.
How to use
The easiest way: copy the message below and paste it into Claude, ChatGPT, Cursor or any AI. It reads the skill and follows the instructions.
Skill link
Ready-to-paste message
How it works
The tool follows a plan to test different parts of the API. It starts by discovering what the API does, then tests how users authenticate, if permissions are correct, if submitted data is valid, and if usage limits are active.
Installation
Easiest way: copy the skill link and paste it into Claude, ChatGPT or Cursor asking it to follow the instructions.
In the terminal (Claude Code, Codex, Cursor), in your project folder:
npx skills add sickn33/agentic-awesome-skills --skill api-security-testingOr download just the file:
curl -L https://raw.githubusercontent.com/sickn33/agentic-awesome-skills/main/plugins/agentic-awesome-skills-claude/skills/api-security-testing/SKILL.md -o SKILL.mdTechnical content (original SKILL.md)
Original text by the author, straight from 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:
- Ask the user to state the exact target URL, IP, account, or resource.
- Ask the user to confirm written authorization and the permitted scope.
- Show the exact command(s) and explain their expected effect.
- 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 fuzzingscanning-tools- API scanning
Actions
- Enumerate endpoints
- Document API methods
- Identify parameters
- Map data flows
- Review documentation
Copy-Paste Prompts
Use @api-fuzzing-bug-bounty to discover API endpoints
Phase 2: Authentication Testing
Skills to Invoke
broken-authentication- Auth testingapi-security-best-practices- API auth
Actions
- Test API key validation
- Test JWT tokens
- Test OAuth2 flows
- Test token expiration
- Test refresh tokens
Copy-Paste Prompts
Use @broken-authentication to test API authentication
Phase 3: Authorization Testing
Skills to Invoke
idor-testing- IDOR testing
Actions
- Test object-level authorization
- Test function-level authorization
- Test role-based access
- Test privilege escalation
- Test multi-tenant isolation
Copy-Paste Prompts
Use @idor-testing to test API authorization
Phase 4: Input Validation
Skills to Invoke
api-fuzzing-bug-bounty- API fuzzingsql-injection-testing- Injection testing
Actions
- Test parameter validation
- Test SQL injection
- Test NoSQL injection
- Test command injection
- Test XXE injection
Copy-Paste Prompts
Use @api-fuzzing-bug-bounty to fuzz API parameters
Phase 5: Rate Limiting
Skills to Invoke
api-security-best-practices- Rate limiting
Actions
- Test rate limit headers
- Test brute force protection
- Test resource exhaustion
- Test bypass techniques
- Document limitations
Copy-Paste Prompts
Use @api-security-best-practices to test rate limiting
Phase 6: GraphQL Testing
Skills to Invoke
api-fuzzing-bug-bounty- GraphQL fuzzing
Actions
- Test introspection
- Test query depth
- Test query complexity
- Test batch queries
- Test field suggestions
Copy-Paste Prompts
Use @api-fuzzing-bug-bounty to test GraphQL security
Phase 7: Error Handling
Skills to Invoke
api-security-best-practices- Error handling
Actions
- Test error messages
- Check information disclosure
- Test stack traces
- Verify logging
- Document findings
Copy-Paste Prompts
Use @api-security-best-practices to audit API error handling
API Security Checklist
- Authentication working
- Authorization enforced
- Input validated
- Rate limiting active
- Errors sanitized
- Logging enabled
…
FAQ
Do I need permission to use this tool?
Yes, explicit written permission from the system owner is mandatory before using this tool for security testing. Unauthorized use is illegal.
What happens before a test is run?
Before any test that might probe, exploit, or access data, the tool will ask for the exact target URL, confirmation of your written authorization and permitted scope. It will also show the exact command and its expected effect, waiting for your explicit confirmation.
Does this tool test all types of APIs?
It specializes in testing REST and GraphQL APIs, focusing on security aspects like authentication, authorization, input validation, and rate limiting.
Details
Original description by the author
API security testing workflow for REST and GraphQL APIs covering authentication, authorization, rate limiting, input validation, and security best practices.
Popularity
- GitHub stars
- 48k
- Ranking position
- #2166
- License
- MIT
- Updated
- 10/15/2026
Comments
- …
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