Cuadre: turning Panama's paper receipts into a tax-ready spreadsheet, with Gemma on my laptop

Description and use

Cuadre turns Panamanian paper receipts into a tax‑ready spreadsheet using a local Gemma 4 E2B model, automating manual transcription while preserving privacy.

Problem

Freelancers and small businesses in Panama must manually transcribe paper receipts into spreadsheets to calculate ITBMS tax credits, a tedious process that often involves blurry photos and privacy concerns.

Outcome

Cuadre processes 6 demo receipts in 6–27 s per image on a 16 GB RAM laptop, correctly calculates ITBMS totals, detects duplicates, flags anomalous RUCs and exempt items, and outputs a ready‑to‑use CSV for accountants.

Workflow

• Place receipt photos in a folder
• Run the Cuadre command
• Gemma 4 E2B reads each photo and returns a JSON with merchant, RUC, date, subtotal, ITBMS, total
• Python code validates fields, detects duplicates and anomalies
• Totals are calculated with Decimal math
• Output files: recibos.csv, resumen.md, review list

Evidence

Cuadre does the typing. You put the receipt photos in a folder and run one command. You get: recibos.csv, resumen.md, a short list of the receipts a human should double-check

Source

The photos are read by Gemma, an open-weight model, running on my own laptop. They never leave the machine.

Source

Python standard library only at runtime, 42 tests, and a cache keyed by the photo's hash, so when you add next week's receipts and run it again, only the new photos are read.

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Gemma runs with temperature: 0 and thinking turned off: transcription doesn't need reasoning, and the same photo always gets the same reading.

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