VanarChain Indexer

A high-performance blockchain indexer for VanarChain that tracks ERC20, ERC721, and ERC1155 token transfers and contract deployments.

Features

• Token Transfer Tracking: Indexes all ERC20, ERC721, and ERC1155 transfer events
• Contract Deployment Detection: Automatically detects and indexes token contract deployments
• Real-time Monitoring: Live watcher for new events as they happen
• Historical Scanning: Batch processing of historical blocks
• REST API: Query endpoints for transfers and deployments
• Performance Optimized: Batch database operations and parallel processing

Requirements

• Node.js 18+
• PostgreSQL 14+

Quick Setup

1. Clone and install dependencies:

git clone <repository-url>
cd vanar-indexer
npm install

2. Environment setup:

cp .env.example .env
# Edit .env with your configuration

3. Database setup:

npm run prisma:generate
npm run prisma:migrate

4. Start development server:

npm run dev

Environment Variables

Create a .env file with the following variables:

# Required
VANAR_RPC=https://your-vanar-rpc-endpoint
POSTGRES_URL=postgresql://username:password@localhost:5432/database_name
START_BLOCK=12345678
END_BLOCK=12345679

# Optional
PORT=3000
LOG_LEVEL=info
NODE_ENV=development

Scripts

• npm run dev - Start development server with hot reload
• npm run build - Build TypeScript to JavaScript
• npm start - Run production build
• npm run prisma:generate - Generate Prisma client
• npm run prisma:migrate - Run database migrations
• npm run prisma:deploy - Deploy migrations to production

Codebase Structure

Core Files

• src/server.ts - Main application entry point, starts HTTP server and indexers

Configuration (src/config/)

• env.ts - Environment variable validation and configuration
• logger.ts - Pino logger setup with pretty printing for development
• client.ts - Viem blockchain client configuration

Database (src/db/)

• client.ts - Prisma database client singleton

Services (src/services/)

• httpServer.ts - Express REST API server with endpoints for querying data
• blockScanner.ts - Historical block scanning service with batch processing
• liveWatcher.ts - Real-time event monitoring via blockchain subscription

Indexers (src/indexers/)

• erc20.ts - ERC20 transfer event indexing logic
• erc721.ts - ERC721 transfer event indexing logic
• erc1155.ts - ERC1155 transfer event indexing logic
• deployment.ts - Contract deployment detection and indexing with token standard detection

Contracts (src/contracts/abis/)

• erc20.json - ERC20 contract ABI for event decoding
• erc721.json - ERC721 contract ABI for event decoding
• erc1155.json - ERC1155 contract ABI for event decoding

API Endpoints

Transfer Queries

• GET /erc20/:address - Get ERC20 transfers for an address (from/to)
• GET /erc721/:contract - Get ERC721 transfers for a contract
• GET /erc1155/:contract - Get ERC1155 transfers for a contract

Deployment Queries

• GET /deployments/type/:type - Get deployments by token standard (ERC20|ERC721|ERC1155)
• GET /deployments/:address - Get deployment info for a specific contract address

How It Works

1. Historical Scanning

• Scans blocks from START_BLOCK to END_BLOCK
• Fetches blocks in parallel for performance
• Detects contract deployments by checking for creation transactions
• Indexes transfer events using contract ABIs
• Uses batch database operations for efficiency

2. Live Monitoring

• Subscribes to new blocks via polling
• Processes new events in real-time
• Maintains same indexing logic as historical scanner

3. Token Detection

• Uses ERC165 supportsInterface for ERC721/ERC1155 detection
• Uses totalSupply() call for ERC20 detection
• Only indexes contracts that are confirmed token contracts

4. Performance Optimizations

• Batch database inserts using createMany()
• Parallel block fetching
• Parallel token standard detection
• Efficient log filtering by event signatures

Database Schema

Tables

• ERC20Transfer - ERC20 transfer events
• ERC721Transfer - ERC721 transfer events
• ERC1155Transfer - ERC1155 transfer events
• ContractDeployment - Token contract deployments with standard detection

Indexes

All tables have indexes on commonly queried fields:

• Transaction hash
• Block number
• Address fields (from/to/contract)
• Token standard (for deployments)

Development

Prisma Studio

npx prisma studio

Opens database browser at http://localhost:5555

Database Reset

npx prisma migrate reset

⚠️ Warning: This will delete all data

Production Deployment

npm run build
npm run prisma:deploy
npm start

Monitoring

The indexer provides detailed logging:

• Block processing progress
• Event counts per batch
• Error handling with context
• Performance metrics

Check logs for:

• Token deployments processed: count: X
• Logs fetched: count: X
• Any error messages with full context

Troubleshooting

Common Issues

1. "Event not found on ABI" - Ensure ABI files are properly imported
2. "Table does not exist" - Run npm run prisma:migrate
3. Slow performance - Check database indexes and batch sizes
4. Missing deployments - Verify token detection logic and RPC connectivity

Performance Tuning

• Adjust batchSize in scanBlocks() for memory vs speed tradeoff
• Monitor database connection pool size
• Consider using connection pooling for high-volume indexing