OpenTakeoff: free, open-source tool lets AI agents measure building plans

OpenTakeoff addresses a long-standing gap: there has been no open-source, web-based takeoff canvas available to the construction and flooring trades at all. The tool originated as the takeoff module of a private flooring estimating app, then was extracted, cleaned up, and released as a genuine alternative — including the One-Click Area flood-fill tracer that commercial tools charge $300/month to provide. The measuring engine itself is production-grade, not a simplified demo.

The July 2026 addition of the MCP server is the key innovation for AI adoption. Until now, AI agents could not measure a real building plan the way an estimator does; OpenTakeoff is the first place they can. Because the same engine runs for both people and agents, every measurement carries provenance — the scale, whether it was one-click or hand-drawn, and whether a person or agent made it. This audit trail travels with the number, which matters for construction bids and accountability.

The tool's architecture keeps data local by default: PDFs and takeoffs never leave your machine, stored in browser IndexedDB and localStorage. An optional team cloud mode via Google Drive is available, but it is strictly additive and off by default. This design preserves the security and ownership benefits of a static site for users who want them.