BuildProof in Claude

Five free construction payment calculators, available to Claude as a connector. Ask in plain words, and Claude runs the numbers through BuildProof. The arithmetic is integer-cent math done in code, never estimated by a model.

Add it in three steps

In Claude, open Settings, then Connectors, and choose to add a custom connector.
Paste this address: https://buildproof.com/api/mcp
When asked, sign in with a free BuildProof account (create one if you do not have one). Then ask Claude for any tool below.

The five tools

Retainage calculatorRetainage held on the work done, retainage released, and retainage still owed, from the contract sum, a percent complete or amount billed, and the retainage rate.“My contract is $1,200,000, I'm 40% complete and the retainage is 10%. How much is held, and what is left if $20,000 is released?”

Pay applicationThe nine-line application for payment and its continuation sheet from a schedule of values, with a printable text version.“Build pay app #4 for Elm Street from these lines and this month's progress.”

Change orderItemize a change: priced items (a lump amount, or quantity times unit price), markup, the contract sum after the change and any change in days, as a change order document with the signature lines left blank.“Price a change order for added blocking: $12,400 plus 10% markup, 5 days.”

SOV front-loading checkScreens a schedule of values for lines that carry money early and checks that the lines add up to the contract. It is a list of questions to ask, not a verdict.“Check this schedule of values for front-loading.”

Lien waiver draftA conditional or unconditional, progress or final waiver for a supported state, with a plain explanation of which one to sign and when.“Draft a conditional progress waiver for Texas, through March 31.”

What is and is not verified

Figures are computed in code from the numbers you give Claude. Check them against your own records before you rely on them.
Lien waiver text is an unverified template. It has not been checked against the statute and is not legal advice. A state without a template returns none.
Nothing is signed, notarized, filed or sent for you.

No data saved

The tools do not read or write any BuildProof project, and your inputs and results are not stored. The only thing kept is a usage counter that limits how many times a day a free account can call the tools.

Using it for real jobs

These calculators work on one job at a time and do not keep anything. BuildProof itself tracks the whole requisition: backup, waivers, insurance and what the owner or lender has approved, with a 45-day free trial and no card.

Start your free trial