REMKEY APPLICATION

1. Overview

Remkey is a specialized flashcard application designed to maximize long-term memory retention through an advanced Spaced Repetition System (SRS).

Unlike traditional applications that rely on outdated scheduling models, Remkey integrates the FSRS (Free Spaced Repetition Scheduler) algorithm. This modern mathematical model dynamically predicts your memory's "forgetting curve" and calculates the optimal time to review each card. By focusing on Stability (S), Difficulty (D), and Retrievability ( R), Remkey ensures you spend less time reviewing what you already know and more time mastering new material.

2. System design and work flow

Link: https://drive.google.com/drive/folders/17OF4ZbusdjAeHsf26TgEUdpG-cSS7X6k?hl=vi

3.Tech Stack

Backend

• Java 21
• Spring Boot 4

Database & Storage

• PostgreSQL
• H2 Database
• Redis

AI Integration

• Google Gemini AI: Generate card automatically.

Algorithm

• FSRS (Free Spaced Repetition Scheduler): The core mathematical model for interval scheduling and memory optimization.

Tools & Others

• Maven
• Docker 14.22-trixie

4. Installation & Setup

Prerequisites

• JDK 21 or higher

• Maven 3.6+

• PostgreSQL 14+

• Gemini API Key (Get it from Google AI Studio)

Clone the Repository

• git clone https://github.com/yourusername/remkey-backend.git

Database Configuration

• Create a database named remkey in your PostgreSQL.

Config file application.yaml

Create file src/main/resources/application.yaml (or use Environment Variables):

spring:
application:
 name: remkey
#    connect to db
datasource:
 url: jdbc:postgresql://localhost:5432/remkey
 username: #your username
 password: #your password
 driver-class-name: org.postgresql.Driver
data:
 redis:
   host: localhost
   port: 6379
#      config jpa for postgres
jpa:
 hibernate:
   ddl-auto: none
 show-sql: true
 database-platform: org.hibernate.dialect.PostgreSQLDialect


flyway:
 enabled: true
 locations: classpath:db/migration
 repair-on-migrate: true
 baseline-on-migrate: true

mail:
 host: smtp.gmail.com
 port: 587
 username: #your email
 password: #your password
 properties:
   mail:
     smtp:
       auth: true
       starttls:
         enable: true
         required: true


# json web token
jwt:
secret-key: #your secret key
valid-duration: 5 #day
refreshable:  3 #day


app:
sec:
 otp-verifier:
   valid-duration: 5 #minutes
   refreshable:  1 #minutes
   request-limit: 5 #times per day
 cors:
   endpoint: "*" #your cors enpoint

server:
servlet:
 context-path: /api/v1/remkey
 port: 8080

Run application as a normal spring app

Postman

Link: https://lovankydev.postman.co/workspace/lovankydev's-Workspace~053387a3-a707-44bc-8a9c-9cfdcdad1ce7/collection/46238050-1c1d4b70-bc20-45d4-84ce-d0fd5c5593db?action=share&source=copy-link&creator=46238050

5.Security

• JWT token with hs256 and
• OTP verification with rate limit and expiration
• Bucket4j

Contact

• Email: lovanky.work@gmail.com
• Phone: +8486535996
• Address: Haiphong, Vietnam.