OpenLedger Backend API

Express.js backend application for managing decentralized applications (Dex) in the OpenLedger ecosystem.

Features

• RESTful API for application management
• PostgreSQL database with Sequelize ORM
• Authentication middleware (wallet-based)
• CORS enabled
• Error handling and logging

Prerequisites

• Node.js (v14 or higher)
• PostgreSQL (v12 or higher)
• npm or yarn

Installation

1. Clone the repository:

git clone <repository-url>
cd open_terminal_backend

2. Install dependencies:

npm install

3. Set up environment variables:

cp .env.example .env

Edit .env file with your database credentials and configuration.

4. Create the database:

# Connect to PostgreSQL
psql -U postgres

# Create database
CREATE DATABASE open_terminal;

Running the Application

Development Mode

npm run dev

Production Mode

npm start

The server will start on http://localhost:3000 (or the port specified in your .env file).

API Endpoints

Health Check

GET /health

Returns the server status.

Create Application

POST /api/create_app

Headers:

• Content-Type: application/json

Request Body:

{
  "name": "My Dex App",
  "wallet": "0x1234567890abcdef...",
  "sign": "signature_string",
  "description": "A decentralized exchange application",
  "networks": ["ethereum", "polygon"],
  "brand_logo": "https://example.com/logo.png",
  "brand_fav_icon": "https://example.com/favicon.ico",
  "user_prompt": "Welcome to my Dex!",
  "design_system_id": "design_123"
}

Required Fields:

• name: Application name
• wallet: Wallet address

Response (Success - 201):

{
  "success": true,
  "data": {
    "uuid": "550e8400-e29b-41d4-a716-446655440000",
    "name": "My Dex App",
    "description": "A decentralized exchange application",
    "brand_logo": "https://example.com/logo.png",
    "brand_fav_icon": "https://example.com/favicon.ico",
    "is_enabled": true,
    "created_at": "2026-01-28T10:30:00.000Z",
    "updated_at": "2026-01-28T10:30:00.000Z"
  }
}

Response (Error - 400):

{
  "success": false,
  "error": "Missing required fields: name and wallet are required"
}

API's

1. Get Chat History

GET /api/chat/:chat_id/history

• Purpose: Fetch complete conversation history for a specific chat
• Returns: All messages (user + AI responses) with metadata
• Example: curl -H "x-wallet-address: emailAddress"
  "http://localhost:4040/api/chat/jALjI5yl2uu/history"

---

2. Get Single Application

GET /api/applications/:uuid

• Purpose: Fetch details of one specific application by UUID
• Returns: Full application details including chat_id, prompts, etc.
• Example: curl -H "x-wallet-address: emailAddress"
  "http://localhost:4040/api/applications/21b4f18f-bea3-440a-9224-dd5b766701b5"

---

3. Get All Applications

GET /api/applications

• Purpose: Fetch all applications for a wallet
• Returns: List of all applications owned by the wallet
• Example: curl -H "x-wallet-address: emailAddress"
  "http://localhost:4040/api/applications"

Database Schema

Applications Table

Field	Type	Nullable	Description
uuid	UUID	No	Primary key
name	STRING	No	Application name
wallet	STRING	No	Wallet address
description	TEXT	Yes	App description
type	STRING	Yes	Application type
networks	ARRAY	Yes	Supported networks
brand_logo	STRING	Yes	Logo URL
brand_fav_icon	STRING	Yes	Favicon URL
system_prompt	TEXT	Yes	System prompt
user_prompt	TEXT	Yes	User prompt
status	STRING	Yes	Application status
vercel_project_id	STRING	Yes	Vercel project ID
wallet_project_id	STRING	Yes	Wallet project ID
design_system_id	STRING	Yes	Design system ID
chat_init_response	TEXT	Yes	Chat initialization
is_enabled	BOOLEAN	No	Enable/disable flag
created_at	TIMESTAMP	No	Creation timestamp
updated_at	TIMESTAMP	No	Update timestamp

Project Structure

open_terminal_backend/
├── config/
│   └── database.js          # Database configuration
├── controllers/
│   └── applicationController.js  # Application logic
├── middleware/
│   └── auth.js              # Authentication middleware
├── models/
│   └── Application.js       # Application model
├── routes/
│   └── applicationRoutes.js # API routes
├── .env.example             # Environment variables template
├── .gitignore              # Git ignore file
├── package.json            # Dependencies
├── server.js               # Application entry point
└── README.md               # Documentation

Authentication

The current implementation includes an authentication middleware that validates all requests. Currently, it returns true for all requests. To implement proper wallet signature verification, modify the middleware/auth.js file.

Error Handling

The application includes comprehensive error handling:

• Input validation errors (400)
• Authentication errors (401)
• Not found errors (404)
• Server errors (500)

Development Notes

• The database will auto-sync on server start in development mode
• Use { alter: true } for development to update tables without data loss
• Never use { force: true } in production as it drops all tables

License

MIT