OpenSEO is an open source SEO platform designed as a self-hostable alternative to tools like Ahrefs and Semrush. It offers keyword research, rank tracking, backlink analysis, site audits, and AI search visibility features powered by DataForSEO data. The platform includes Model Context Protocol (MCP) support, allowing AI agents like Claude and Codex to query SEO data and perform research tasks directly. Users can self-host it for free or pay for usage-based access without a fixed monthly subscription.