openSquat is a production-grade CLI tool for detecting domain squatting threats including typosquatting, IDN homograph attacks, doppelganger domains, and phishing. It operates in three modes: Community (free NRD feed with local Levenshtein detection), Premium Feed (paid feed with same local pipeline), and Premium API (server-side lookalike detection per keyword). The tool downloads daily newly registered domain feeds, compares user-defined keywords using an optimized native Levenshtein algorithm with early exit, and supports post-processing filters such as Quad9 DNS reputation, VirusTotal checks, certificate transparency log analysis, phishing database cross-referencing, and port scanning. Output is available in TXT, JSON, or CSV formats. The architecture is modular with clear separation of concerns: feed management, detection engine, API client, DNS validation, homograph detection, and output formatting. The codebase demonstrates strong engineering practices including type hints, dataclasses, thread-safe rate limiting, connection pooling, and security-conscious header handling. It is actively maintained with a detailed changelog and a comprehensive test suite covering key modules.