What it does
Letter Assistant is a native iPhone proof of concept for understanding complex or unfamiliar letters and managing their next steps. It supports English medical and health-insurance letters, bank and credit-card statements, and everyday bills or fee notices. Explanations and calendar text are generated in the selected English or Simplified Chinese app language.
How it works
Photograph a letter, select photos, or import a PDF. The app checks readability locally and keeps the pages in order. When the user taps Analyze document, a Mac-hosted Deno relay sends the images to an operator-configured vision model. The app presents an explanation, relevant facts, actions and dates with source references.
For an applicable action, the user reviews the event title, date, time zone, reminder and notes before adding it to the default iPhone calendar. Date-only deadlines use all-day events; appointments and explicit timed cutoffs use timed events. The app requests write-only calendar permission and displays a save result.
How it was built
The project uses the Devpost Learn Skill Pack with Codex. The repository includes the approved scope.md, prd.md and spec.md, the implementation checklist, and an offline app map tracing capture, analysis and calendar creation. The client uses SwiftUI and Apple camera, Vision, PDFKit and EventKit frameworks. The relay and shared provider/schema validation modules use TypeScript and Deno. Operators supply their own compatible AI provider account and key; no shared project key is included.
Verification and current limits
The core capture/import, fresh analysis and saved-calendar-event journey was checked on an iPhone, including event date, reminder and notes, and the creator confirmed demo readiness. Backend type checking and 38 automated tests passed in the reviewed working tree. These tests do not establish universal AI accuracy or complete real-device edge-case coverage.
AI extraction can be wrong, particularly for conditional actions; important details must be checked against the letter. The prototype requires Xcode installation, a Mac relay and a compatible provider. Photos and analysis are temporary session data; there is no account, archive, chat or synchronization. English input and English/Simplified Chinese output are supported in this version. Additional languages and broader accessibility and notification-delivery validation remain future work.
Development practice
The project separates source facts, scheduling estimates and user-edited calendar values. Verification compares the proposed event with the event actually saved in Calendar. This provides a concrete way to test an end-to-end feature rather than relying on a successful build alone.
Try it
Follow the repository README to configure your own key and relay token, run the Deno relay on your Mac, and install the LetterAssistant-Test scheme on an iPhone with your own signing team. The repository includes the MIT license and fictional test fixtures.
Built With
- codex
- deno
- eventkit
- openai
- openrouter
- pdfkit
- swift
- swiftui
- typescript
- vision
- xcode