Kingfisher is an open-source secret detection and validation tool developed by MongoDB that scans code repositories for hard-coded credentials and API keys while validating their activity in real-time. Designed for on-premises use, it enhances security by reducing false positives and ensuring that sensitive data remains within the user's infrastructure. Kingfisher integrates seamlessly with CI/CD pipelines and supports various programming languages, making it a versatile solution for developers and security teams.