What should I use for API security testing?

For API security testing, a good practical stack is:

Core tools

• Burp Suite (great all-around for manual testing, intercepting, fuzzing, auth/session checks)
• OWASP ZAP (good open-source alternative, solid for scanning and proxying)
• Postman or Insomnia (useful for functional testing, but not security tools by themselves)

API-focused testing

• Burp Suite Professional + REST/GraphQL helpers if you’re testing modern APIs
• OWASP ZAP API Scan for automated baseline checks
• Nuclei for fast template-based checks against known issues
• Kiterunner or ffuf for endpoint discovery and parameter fuzzing

If you use GraphQL

• InQL or GraphQL Voyager/GraphQL tools
• Burp extensions for GraphQL introspection/testing

For code/dependency/security pipeline

• Snyk, Dependabot, or Trivy for dependency/container issues
• Semgrep for code-level API security patterns
• GitHub CodeQL for deeper SAST checks

What I’d recommend by use case

• Beginner / free: OWASP ZAP + Postman + Nuclei
• Professional / manual testing: Burp Suite Pro
• Automation in CI/CD: ZAP + Nuclei + Semgrep + Trivy
• GraphQL APIs: Burp + GraphQL-specific tooling

Most important testing areas

When testing APIs, focus on:

• Broken authentication
• Broken object-level authorization (BOLA/IDOR)
• Broken function-level authorization
• Excessive data exposure
• Mass assignment
• Injection flaws
• Rate limiting / abuse controls
• JWT/session issues
• CORS misconfigurations
• Logging/monitoring gaps

If you want, I can recommend a specific toolkit based on your API type:

• REST
• GraphQL
• gRPC
• internal microservices
• public API
• CI/CD automation