The owner's view of the build.
Keystone is project-controls software for owner's representatives and small developers. It checks the contractor's monthly pay application before money moves.
The problem
Every month, someone has to check the contractor's bill.
On a construction project, the owner's representative stands between the owner and the general contractor. Each month the contractor submits a pay application, and the owner's rep confirms the work billed matches the contract, the change orders, the retainage and the lien waivers before the owner pays.
At small firms that review still happens in spreadsheets and email. Tools built for this work are priced for large developers and lenders. A mistake costs real money, and nobody finds it until closeout.
The product
One record of the contract, from first draw to closeout.
Pay-application review
Reconciles the AIA G702 summary against the G703 line items, checks percent complete and retainage, and lists each exception before the owner pays.
Contract and budget control
Tracks the budget, change orders, allowances and forecast, so the contract sum on every draw ties back to an approved change.
Lien waivers and insurance
Tracks conditional and unconditional waivers for the contractor and subcontractors, plus insurance certificates, and warns when one is missing or late.
Owner and lender outputs
Produces the draw package, owner reports and correspondence from the same numbers, so what the owner reads matches what was reviewed.
Built on Claude
AI reads the paperwork. People approve the money.
Keystone uses Claude to read scanned pay applications, flag exceptions in a draw, and draft owner reports and correspondence. These features are built and tested. The app itself was designed and built with Claude Code.
Construction pay applications arrive as scanned PDFs in dozens of layouts. Reading them accurately is the slowest part of an owner's rep's month, and the part where AI helps most.
- Math is deterministic. Every dollar figure is calculated in code, not generated by a model.
- Claude flags, a person decides. No payment is approved by AI.
- AI is opt-in. It is off by default, enabled per project and per user.
- Contractor documents are untrusted input. AI features are hardened against instructions hidden in uploaded files.
Where it stands
Built from scratch and running on a live project.
About
Built in the DC region, for the DC region.
Westover Labs LLC is a Virginia company formed in October 2026 to build software for owner's representatives and small developers. Keystone is its first product.
Contact
For a walkthrough, a pilot on your project, or anything else, email mason@pdg-dev.com.
Prefer to look first? The live demo runs on a fictional sample project.