OpenSEO

The monthly subscription fees paid by people who do SEO to Ahrefs and Semrush are not small amounts. OpenSEO is open source under the MIT protocol, and its functions cover keyword research, competitive product analysis, external link query, ranking tracking and site audit. It is basically the core module of these two companies and supports MCP, allowing AI agents to directly call its data for analysis and reporting.

The hosted version is billed on a per-use basis, with paid plans starting at $10 per month; self-hosting is free for those willing to do the work themselves. The coverage of data sources is currently not as good as that of older tools, but it is an option worth trying for independent webmasters with limited budgets, small marketing teams, and developers who want to integrate SEO data into automated processes.