Paperclear

Inspiration

In Japan, important letters from the city office, the pension office, or the tax office arrive in dense, formal Japanese. For foreign residents, and for people helping an elderly parent, the hard part is not the vocabulary. It is one question: what do I need to do, and by when? Translation apps give you every word of the letter and still leave that question unanswered.

What it does

Paperclear is a desktop app. You drop in a photo of a document (or pick a file, or use the camera), and it shows:

• The deadline, large and in red, with the days remaining
• Three steps: what to do, by when, and how
• Era dates converted: a date written as "Reiwa 8" is shown as 2026, with the original kept beside it so you can check
• Plain Japanese or English, switched instantly with one click

If the deadline has already passed, it says so clearly instead of counting down. If the document has no deadline, it says that too, rather than guessing one.

Who it's for

Foreign residents in Japan, and family members who help an elderly parent with official mail.

How I built it

I am a beginner, and I followed the Devpost Learn skill pack with Claude Code: scope, requirements, spec, then build. The planning documents are in the devpost/ folder of the repository.

The app is built with Electron, HTML, CSS, and JavaScript. It reads the photo with Google's Gemini API and asks for a structured result, so the deadline and the steps always appear in the same place. Both languages are prepared in the first read, which is why switching is instant.

Challenges

• The Gemini API was often overloaded during development. I added retries, a timeout, and a fallback model.
• Japanese era dates were first reported as "no deadline found". Fixing the conversion, and an off-by-one-day error, took several rounds.
• An overdue document first showed a negative number of days. It now shows a clear overdue notice.
• Drag and drop from a folder did not work at first.

What I learned

Writing the scope and the spec before any code kept the project small enough to finish. I also learned that the states where the app has nothing to show (no deadline, an overdue date, an API error) need as much design as the main screen.

What's next

• Calendar reminders for the deadline
• More languages
• Tests with real users and more document types

Notes

Paperclear is a proof of concept. Every document shown in the demo is fictional. The API key is stored only on the user's own computer. The narration in the video is an AI-generated voice.

Built With

• claude-code
• electron
• gemini
• javascript
• node.js