StackCheck

In India people pay for a flat years before it exists. Every builder has to file a quarterly progress report (QPR) with the state RERA, with photos, percent complete and money figures. Nobody compares one quarter with the next, or the photos with the claims, so gaps go unnoticed. StackCheck is a free web app for homebuyers. You paste public RERA PDF links (one per line or separated by commas) or upload PDFs, site photos or a short site video. It reads each quarter and runs nine checks: the builder's photo against the claimed progress, reused photos, photo dates, progress that goes backwards, copy-pasted quarters, money against progress, arithmetic on the money page, missing quarters, and your own site video against the filing. The design rule is that a wrong accusation is worse than no answer. Floor counts need two independent methods to agree: SAM 3.1 finds repeated rows of windows and balconies, and Muse Spark counts storeys by looking at the photo. If they disagree, the app says "can't verify". The verdicts come from plain code, not from a model's opinion. Models only read facts and propose what to try next, a bounded agent gets at most 3 logged steps, and every finding links to its page or photo. The wording is always: a gap is a question to ask the builder or RERA, not proof of wrongdoing. What it found: on one real Bihar project, the money page shows net amount above collected minus spent in 3 quarters. The app flagged it and it matches the PDF page. On another real filing, the report gives percent complete, not floors. After entering the building's 5 floors, the claim became 4 slabs, the builder's own elevation photo showed 4 counted floor rows with the boxes drawn on it, and the result was OK. Limits, stated plainly: Bihar filings give percent complete, so the user types the floors above ground when the filing does not say. Photo counts for very tall towers come out low and are labelled estimates. Video counts never go above "estimate" and never raise a flag by themselves. Accuracy of filing reading is not fully measured yet. Solo build with Muse Code, hosted on Modal. No account, no card. Project names are anonymised in the public demo.