# StarryLingo

> A full-stack English language learning web application built with Next.js

StarryLingo helps users learn English through reading articles, managing vocabulary (keypoints), and using spaced repetition for review. The app features AI-powered content generation, audio support, and a freemium model with credits system.

## Core Features

- **Article Learning**: Read English articles with sentence-by-sentence translations and audio
- **Vocabulary Management**: Extract and save keypoints (words/phrases) from articles
- **Spaced Repetition**: FSRS-based review system for optimal memorization
- **AI Generation**: Auto-generate articles, translations, and word definitions
- **Audio Support**: Text-to-speech and word pronunciation
- **Collections**: Organize saved vocabulary into custom groups

## Tech Stack

- Framework: Next.js 16.1 (App Router)
- Database: PostgreSQL with Drizzle ORM
- Auth: Better Auth (email OTP)
- AI: Vercel AI SDK with DeepSeek, Google, OpenRouter
- Styling: Tailwind CSS 4 + Shadcn/UI
- Audio: Deepgram SDK
- Payment: Stripe
- Storage: Tencent COS

## Learner Levels

- Elementary
- Intermediate
- Advanced
- Professional

## API Endpoints

### Articles
- GET /api/article - Get single article with sentences
- GET /api/articles - Get user's articles list
- POST /api/article/create - Create article with AI generation
- DELETE /api/article/delete - Delete article

### Keypoints (Vocabulary)
- POST /api/keypoint/create - Create keypoint
- POST /api/keypoint/generate - AI-generate keypoints from article
- GET /api/keypoint/favorites - Get user's favorite keypoints
- POST /api/keypoint/favorites/batch - Batch update favorites
- POST /api/keypoint/[id]/favorite - Toggle favorite status

### Review System
- GET /api/review/due - Get cards due for review
- POST /api/review/grade - Grade review card
- GET /api/review/stats - Get review statistics

### Credits & Activation
- GET /api/credits - Get credit balance and history
- POST /api/activate - Activate trial with code

### Other
- GET /api/word - Get word details from dictionary
- GET /api/lemma-inflections - Get word lemma and inflections
- GET/POST/DELETE /api/collection - Manage collections
- POST /api/stream-translate - Streaming translation

## Browser Extension

StarryLingo includes a Chrome extension for capturing web snippets and sending them to the app for learning.