# SheetProof

- **Event:** [Meta Global AI Developer Hackathon](https://cerebralvalley.ai/e/meta-ai-developer-hackathon)
- **When:** Oct 26, 12:00 PM – Nov 4, 9:00 PM (EST)
- **Where:** Online
- **Team:** [Jonathan Ream](https://cerebralvalley.ai/u/jon_ai_ctrl)
- **GitHub:** https://github.com/PhantomGuy1/sheetproof
- **Demo video:** https://www.youtube.com/watch?v=2otOEK6WiIU
- **Gallery:** https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery
- **Page:** https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/246

SheetProof

"Just drop in a Pic of your receipt or anything and it uploads to the sheet"

From shoebox to spreadsheet — without touching a keyboard.

SheetProof was built from a real day-job problem: at a print shop, job-tracking rows are hand-typed into spreadsheets from printed paper tickets. That work is slow and error-prone, and it is the same work facing any shop, studio, club, team, creator, author, or household whose records arrive on paper or in messy files.

Drop in a receipt photo or another messy document and SheetProof returns a clean spreadsheet with a complete record of what it changed. Intake covers HEIC and WebP photos,.txt files, PDFs, CSVs, and emails.

Pic drop is free and keyless. Pictures are read through the Front Desk — a small relay that calls Meta's muse-spark-1.3 model server-side — so the person using SheetProof needs no API key and no sign-in for pic drop. This was proven end-to-end on the developer's own PC with his own real receipt photos on 2026-10-31. There is no SheetProof account or sign-in of any kind. The file-based core works offline; the AI reading is the online part.

Two rules govern the product. First, the AI never sources a number: if a figure is not on the document, it does not exist, and nothing is invented to fill a gap. Second, every change SheetProof makes is logged — the change log is the trust feature, so a cleaned sheet can always be checked against the paper it came from.

Accuracy, stated exactly: on a deterministic benchmark, SheetProof scored 335 of 335 fields correct, and 25 of 25 on an adversarial attack set. That benchmark ran with a stub brain (StubBrain), so it measures the deterministic cleaning core — it does not measure live-AI extraction quality, and it is not presented as doing so. The automated test suite stands at 1,538 tests passing in the repository tree.

Spreadsheet delivery, stated exactly: a live write into Google Sheets is proven. For Microsoft Excel, the proven path is the finished-file download. The Excel COM and LibreOffice Calc UNO integrations are built and have been tested against fake transports only; they are not claimed as proven.

SheetProof also has a second door, Second Eyes: glance at a shelf, speak a count, and the confirmed count lands in the same spreadsheet. It was verified live on 2026-10-29: 42 screws, 16 bolts, and 7 tape measures were read exactly; a deliberately wrong spoken count ("18 bolts") was blocked with an exact callout and nothing landed until it was corrected. The total cost of that live test was $0.12.

Two disclosures about the demo film: the demo (v3, 3 minutes 39 seconds) was the best of 3 disclosed extraction takes for its receipt run. And SheetProof does not auto-flag voided entries.

Live verification — Oct 31, 2026: a full live sweep over 49 documents (667 scored cells) scored 96.3% exact match (642/667), with 8 ungrounded invented values after declared grounding; the live auditor probe caught its planted error case (1/1) with no false positives.

## More from Meta Global AI Developer Hackathon

- [The Dealer Social](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/243)
- [86TO88](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/244)
- [Nguyen Quoc Anh](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/245)
- [ReelDirector](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/247)
- [xneo1111](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/248)
- [60-Second Fire Check](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/249)

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