Top API pentest tools in 2026 pair OpenAPI-aware scanning, auth testing, fuzzing, and CI/CD integration to find exploitable flaws before attackers do.

Implement OAuth 2.0 safely: use Authorization Code with PKCE, keep secrets server-side, rotate credentials, and never embed client secrets in mobile, SPA, or public code.

Resolve CORS in complex SPAs by aligning API origins, preflight headers, credentials, and proxy rules-then log OPTIONS failures to pinpoint misconfigured gateways.

Backward-compatible REST APIs preserve contracts: add optional fields, avoid changing meanings, version only for breaking changes, and document deprecations with clear timelines.

Fix bottlenecks by mapping vendor quotas, batching calls, adding adaptive retries, and caching repeat requests to keep third-party integrations reliable under rate limits.