Indexa – ERC-20 Token Transfer Indexer

Indexa is a backend indexing service that connects directly to the Base blockchain and indexes real on-chain ERC-20 token transfer data into a PostgreSQL database.
It listens to live events (and historical blocks) from the Base network and stores verified blockchain data exactly as it exists on-chain.

Indexa also includes an AI-powered natural language interface, allowing users to control indexing behavior using simple human-readable commands—without writing SQL queries or modifying code.

🚀 Features

• Indexes real-time ERC-20 Transfer events from the Ethereum blockchain

• Stores from, to, and value fields into a PostgreSQL database

• Supports natural language queries via AI for flexible indexing

• Users can issue commands like:

  • Index transfers for this address

  • Only index the from and value fields

  • Index this particular address from block 2000000

No need to write raw queries or modify code to change indexing target

📁 Folder Structure

backend/
├── env.sample               # Sample environment variables
├── node_modules/            # Installed dependencies
├── package.json             # Project metadata and scripts
├── package-lock.json        # Locked dependency versions
├── tsconfig.json            # TypeScript configuration
├── src/                     # Source code
│   ├── config/              # DB and blockchain config (e.g., Sequelize, provider)
│   ├── models/              # Sequelize models (e.g., Transfer.ts)
│   ├── migrations/          # Sequelize migration files
│   ├── services/            # Logic for indexing, saving to DB
│   ├── utils/               # Helper functions
│   └── index.ts             # App entry point

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⚙️ Getting Started

1. Clone the Repository

git clone https://github.com/dimka90/indexer.git
cd backend

2. Configure Environment Variables Copy the sample .env and configure it:

cp env.sample .env

Update .env with your credentials:

INFURA_URL=https://mainnet.infura.io/v3/YOUR_INFURA_KEY
DB_HOST=localhost
DB_USER=your_user
DB_PASSWORD=your_password
DB_NAME=indexa_db
DB_PORT=5432
OPEN_AI_KEY=

3. Install Dependencies

npm install

4. Create the Database Make sure PostgreSQL is running, then

create your database:

5. Run Migrations Apply your database schema:

npx sequelize-cli db:migrate

6. Start the Indexer

npm run start

🔧 Technologies Used

1. Node.js
2. TypeScript
3. PostgreSQL
4. Sequelize ORM
5. Web3.js
6. dotenv