DocQuery connects Excel workbooks, Google Sheets, or Airtable bases alongside PDFs, contracts, and invoices, then uses AI to extract and link them into relational tables with foreign keys. The resulting data is served over REST, GraphQL, and a Model Context Protocol server compatible with Claude and Cursor. Changes in the source spreadsheet automatically sync back to the API, keeping everything current. Users can filter, paginate, and traverse related rows without writing SQL or managing migrations.