OneForAll is a comprehensive subdomain enumeration and reconnaissance tool designed for security researchers and penetration testers. It aggregates subdomains from over 60 passive sources (certificate transparency logs, DNS datasets, search engines, threat intelligence feeds, and web crawlers), performs active brute-forcing via massdns, and enriches results with DNS resolution, HTTP probing, CDN detection, wildcard filtering, and subdomain takeover risk assessment. The tool is built as a modular Python CLI application, with each data source implemented as an independent plugin inheriting from base classes in `common/`. Output is stored in a SQLite database and can be exported to CSV, JSON, XLSX, and other formats. While primarily an application, the repository also includes curated data files (subdomain wordlists, CDN CIDR ranges, cloud service fingerprints) that are valuable for security research.