AWS Security Agent is an AI-powered security tool that provides automated security validation throughout the software development lifecycle. The agent operates across design, development, and deployment phases to identify and report security vulnerabilities. The tool performs three primary functions: design security reviews, code security reviews, and on-demand penetration testing. For design reviews, it analyzes product specifications, architecture documents, and technical designs against AWS best practices and organizational security requirements. During development, it automatically analyzes pull requests for security issues and provides remediation guidance directly in developer workflows. The penetration testing capability executes on-demand tests that discover verified security vulnerabilities through multi-step attack scenarios. Tests are customized to specific application contexts and data flows, providing reproducible proof of vulnerabilities along with implementation-ready fixes. Security teams can centrally define organizational security standards that are automatically validated during reviews across all applications. The agent provides context-aware recommendations based on application-specific requirements and organizational policies. The tool aims to transform periodic security assessments into continuous validation, reducing penetration testing timeframes from weeks to hours. It is designed to scale security expertise across multiple applications and development teams while maintaining consistent security standards.