Witcher is a NodeJS tool designed to implement and monitor application security controls at scale in GitHub. It supports modules like GHAS, Dependabot, Secret Scanning, CodeQL, IaC, and Workflows. The tool allows users to enable, disable, check the status, and manage alerts for these modules across an organization. It can be installed and run using Docker, requiring environment variables for GitHub authentication and optional integrations. Witcher offers features like daily summaries, mass actions, and integrations with Slack, SIEM, and Jira. Repositories can be excluded from core functions via a configuration file. Common commands include listing GHAS status, enabling/disabling GHAS, and retrieving code scanning vulnerabilities. The daily summary provides a comprehensive overview of security statuses, including GHAS, Dependabot, and Code Scanning. Witcher excludes public, archived, and deprecated repositories from its operations and has a roadmap for future enhancements.