Bitcoin Custodial Wallet App

The Bitcoin Custodial Wallet App is a custodial wallet application designed to facilitate the purchase of Bitcoin using fiat currency. It consists of a Node.js backend API and a React.js frontend interface, integrated with Plaid for secure bank account linking and a local regtest Bitcoin node for simulating Bitcoin transactions.

Project Overview

The app’s backend manages user authentication, bank account linking, and bitcoin transactions, while the frontend provides a user-friendly interface for seamless interaction. Both components are configured for local development, with options to simulate transactions using regtest mode on Bitcoin Core.

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Technologies Used

Backend

• Node.js: JavaScript runtime for server-side scripting.
• Express: Minimal, flexible framework for building backend APIs.
• Bitcoin Core: Full node implementation of the Bitcoin protocol (using regtest mode for transaction simulations).
• Plaid: API for securely linking user bank accounts in a sandbox environment.
• SQLite3: Lightweight SQL database for development and testing.
• Sequelize: ORM for interacting with SQLite.

Frontend

• React.js: Frontend framework for building user interfaces.
• Nuxt.js: Modern web application framework.
• Plaid Link: Plaid’s integration for securely linking user bank accounts.
• Material-UI: UI framework for responsive design and React components.

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Backend Setup

Environment Variables

Create a .env file in the backend folder with the following variables:

BASE_URL=http://localhost:3000
PORT=8080

DATABASE_DIALECT=sqlite
DATABASE_FILE_PATH=database/sqlite/database.db

PLAID_ENV=sandbox
PLAID_CLIENT_ID=YOUR_PLAID_CLIENT_ID
PLAID_SECRET=YOUR_PLAID_SECRET
PLAID_PRODUCTS=auth,transactions
PLAID_REDIRECT_URL=http://localhost:3000/api/plaid/callback

BITCOIN_PORT=18443
BITCOIN_NETWORK=regtest
BITCOIN_RPC_USERNAME=YOUR_BITCOIN_RPC_USERNAME
BITCOIN_RPC_PASSWORD=YOUR_BITCOIN_RPC_PASSWORD
BITCOIN_CLI_PATH=/path/to/your/bitcoin-cli

JWT_SECRET=YOUR_JWT_SECRET
JWT_EXPIRES=1h

Configure Database

Create the database.db file:

touch backend/database/sqlite/database.db

Run DB migrations:

sequelize db:migrate --config src/config/db.config.json --migrations-path database/migrations

Getting Started

1. Navigate to the backend folder:

   cd backend

2. Install dependencies:

   npm install

3. Run the development server:

   npm run dev

4. Access the backend API at http://localhost:8080.

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Frontend Setup

Environment Variables

Create a .env file in the frontend folder with the following variable:

NEXT_PUBLIC_API_BASE=http://localhost:8080

Getting Started

1. Navigate to the frontend folder:

   cd frontend

2. Install dependencies:

   npm install

3. Run the development server:

   npm run dev

4. Access the app at http://localhost:3000.

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Features

Main Features

• User Authentication:

  • Secure email and password login.
  • Session management to keep users logged in.

• Bank Account Linking:

  • Plaid Link integration for secure bank account connections.
  • Utilizes Plaid’s sandbox for testing.

• Bitcoin Purchase Flow:

  • Allows users to buy bitcoin with fiat.
  • Simulates transactions via a local Bitcoin node.

• Responsive UI:

  • Material-UI for optimal UX on desktop and mobile.
  • Intuitive navigation and components.

Bonus Features

• Bank Account Balance Check: Prevents transactions when funds are insufficient.
• Multiple Bank Account Support: Allows users to manage and select from multiple bank accounts.

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Additional Commands

Linting

Run linting for backend or frontend:

npm run lint
npm run lint:fix

Tests

Run backend or frontend tests:

npm run test

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License

This project is licensed under the MIT License.