Gasless Gossip Backend

This repository contains the NestJS backend service for Gasless Gossip, a decentralized messaging platform that integrates seamless cryptocurrency transfers into secure, wallet-to-wallet communication.

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Overview

Gasless Gossip’s backend is built with NestJS, providing REST APIs and WebSocket connections to power our decentralized messaging platform on StarkNet’s Layer 2 scaling solution. The service handles message routing, token transfer integration, and user authentication while maintaining end-to-end encryption for privacy.

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Tech Stack

• Framework: NestJS
• Database: PostgreSQL with Prisma ORM
• API: REST (Express)
• Real-time: WebSockets (Socket.io)
• Blockchain: StarkNet.js
• Authentication: JWT and wallet signature verification

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Prerequisites

• Node.js v20+
• PostgreSQL v13+
• Yarn or npm

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Installation

# Clone the repository
git clone https://github.com/gaslessgossip/backend.git
cd backend

# Install dependencies
npm install
# or yarn install

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Environment Setup

Create a .env file in the project root with the following variables:

# Database
database_url="postgresql://username:password@localhost:5432/gaslessgossip?schema=public"

# JWT
jwt_secret="your-secret-key"
jwt_expiration="24h"

# StarkNet
starknet_provider_url="https://alpha-mainnet.starknet.io"
contract_address="0x..."

# Server
port=3000
node_env=development

# WebSockets
ws_port=3001

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Database Setup

# Generate Prisma client
npx prisma generate

# Create database tables
npx prisma migrate dev --name init

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Running the Application

# Development mode
yarn start:dev

# Production mode
yarn build
yarn start:prod

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API Documentation

Once the server is running, Swagger docs are available at:
http://localhost:3000/api

Endpoints

Authentication

• POST /api/auth/login – Authenticate using wallet signature
• POST /api/auth/verify – Verify JWT token

Users

• GET /api/users – List users
• GET /api/users/:walletAddress – Get user details
• PUT /api/users/:walletAddress – Update user profile

Messages

• GET /api/messages/:chatId – Get chat messages
• POST /api/messages – Send new message
• DELETE /api/messages/:messageId – Delete a message

Chats

• GET /api/chats – List user’s chats
• POST /api/chats – Create new chat
• POST /api/chats/:chatId/members – Add members to chat

Tokens

• GET /api/tokens/balances – Get token balances
• POST /api/tokens/transfer – Initiate token transfer

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WebSocket Endpoints

• Messages: ws://localhost:3001/messages
• Notifications: ws://localhost:3001/notifications

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Core Features

• User Authentication: Wallet-based signature verification
• Messaging: Real-time encrypted delivery
• Token Transfers: StarkNet smart contract integration
• Group Chats: Creation and management of group conversations
• DAO Treasury: Community-driven financial management tools

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Testing

# Unit tests
yarn test

# E2E tests
yarn test:e2e

# Test coverage
yarn test:cov

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Project Structure

src/
├── app.module.ts          # Main application module
├── main.ts                # Entry point
├── auth/                  # Authentication modules & guards
├── common/                # Shared utils & interceptors
├── config/                # Configuration modules
├── controllers/           # REST API controllers
│   ├── messages.controller.ts
│   ├── users.controller.ts
│   └── tokens.controller.ts
├── modules/
│   ├── messages/          # Message handling services
│   ├── users/             # User management
│   ├── tokens/            # Token transfer modules
│   └── groups/            # Group chat functionality
├── prisma/                # Prisma schema & migrations
│   ├── schema.prisma
│   └── migrations/
├── services/              # Business logic
│   ├── messages.service.ts
│   ├── users.service.ts
│   └── tokens.service.ts
└── websockets/            # WebSocket gateways

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Database Schema

model User {
  id            String    @id @default(uuid())
  walletAddress String    @unique
  username      String?
  avatarUrl     String?
  createdAt     DateTime  @default(now())
  updatedAt     DateTime  @updatedAt
  chats         ChatMember[]
  sentMessages  Message[] @relation("SentMessages")
}

model Message {
  id            String        @id @default(uuid())
  content       String
  chatId        String
  senderId      String
  sender        User          @relation("SentMessages", fields: [senderId], references: [id])
  chat          Chat          @relation(fields: [chatId], references: [id])
  createdAt     DateTime      @default(now())
  tokenTransfer TokenTransfer?
}

model Chat {
  id        String      @id @default(uuid())
  name      String?
  isGroup   Boolean     @default(false)
  createdAt DateTime    @default(now())
  updatedAt DateTime    @updatedAt
  messages  Message[]
  members   ChatMember[]
}

model ChatMember {
  id       String   @id @default(uuid())
  chatId   String
  userId   String
  role     String   @default("MEMBER")
  joinedAt DateTime @default(now())
  chat     Chat     @relation(fields: [chatId], references: [id])
  user     User     @relation(fields: [userId], references: [id])

  @@unique([chatId, userId])
}

model TokenTransfer {
  id           String   @id @default(uuid())
  messageId    String   @unique
  message      Message  @relation(fields: [messageId], references: [id])
  tokenAddress String
  amount       String
  tokenType    String
  tokenId      String?
  txHash       String?
  status       String
  createdAt    DateTime @default(now())
}

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Contributing

Please see CONTRIBUTING.md for our code of conduct and pull request guidelines.

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License

This project is licensed under the MIT License. See LICENSE for details.

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Blockchain Integration

Gasless Gossip integrates with StarkNet for gas-efficient token transfers. The backend communicates with Cairo smart contracts to facilitate:

• ERC-20, ERC-721, and ERC-1155 token transfers
• Message signature verification
• DAO treasury management

Check the src/modules/blockchain directory for implementation details.

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Deployment

Deployment and CI/CD instructions are available in DEPLOYMENT.md.