Synack API Penetration Testing is a service that provides offensive security testing for API attack surfaces. The service utilizes the Synack Red Team (SRT), a community of security researchers who conduct penetration testing on APIs to identify exploitable vulnerabilities. The platform provides visibility into researcher attack traffic during testing, with coverage analytics that enumerate domains, paths, and API endpoints. Testing can be performed on APIs as part of web application assessments or as standalone headless API testing for endpoints not accessible through web user interfaces. Researchers test for common and critical vulnerabilities including those listed in the OWASP API Top 10. The service delivers vulnerability reports with actionable findings that can be managed through the Synack platform or integrated with existing vulnerability management systems. The platform includes patch verification capabilities, allowing organizations to request retesting after remediation. Direct communication with researchers is available through the platform for clarification on findings. Organizations can generate PDF reports for compliance auditors that detail API security testing coverage, identified vulnerabilities, and remediation efforts. The service addresses the growing attack surface of APIs in web applications and B2B communication technologies.