04 / Everyday Life
Keep It Useful.
Build With Care.
The technical foundations of local bill storage and recognition.
Documentation reviewed 8 October 2026. These sources explain capabilities and limits; they do not validate S7's accuracy or warranty eligibility.
01Project documentation
Tesseract.Js Local Recognition
Tesseract.js recognizes text from images in a browser worker. Its worker, core and language-data paths can be set locally. PDFs require a separate parsing or rendering step.
Citation and reading notes
Citation: Tesseract.js contributors. Local Installation, README and FAQ. Project documentation, accessed 8 October 2026.
Material reviewed: Official local-installation instructions, browser examples and PDF limitations.
Scope: OCR can misread text. Recognition confidence does not prove that a date, product or warranty field is correct.
S7 interpretation: Bundle the runtime and English data locally, then let people review editable suggestions before saving.
02Project documentation
PDF.Js Parsing And Rendering
Mozilla's PDF.js provides browser-based PDF parsing and rendering. Selectable text can be extracted, while scanned pages can be rendered into images for recognition.
Citation and reading notes
Citation: Mozilla and PDF.js contributors. PDF.js project homepage and bundled licensed API distribution. Accessed 8 October 2026.
Material reviewed: Official project description and the existing PDF parsing/rendering interfaces used by S7.
Scope: Parsing does not verify a receipt's authenticity or establish warranty coverage. Encrypted or unusual PDFs may require manual entry.
S7 interpretation: Read text when available and recognize scanned pages locally, with limits to protect browser memory.
03Platform documentation
IndexedDB Local Records And Files
IndexedDB supports structured browser data, files and blobs through transactions. Storage is scoped to the website origin and is subject to browser quotas and eviction behavior.
Citation and reading notes
Citation: MDN contributors. IndexedDB API. Accessed 8 October 2026.
Material reviewed: Official API overview, transaction model, origin isolation and storage limitations.
Scope: Local storage is not a managed backup and does not protect data from someone using the same browser profile.
S7 interpretation: Save bills and records together, keep trash recoverable, and provide complete export/import backups.
