Proxy Contract Example

This example demonstrates how to properly index events from a proxy contract pattern, specifically using Compound's Comptroller contract as an example.

Key Components

1. Entity Generation

The example uses solidity-events-to-typeorm to automatically generate TypeORM entities from contract ABIs. This is configured in scripts/generate.ts:

export const config: Config = {
  output: {
    path: outputPath,
    entities: path.resolve(outputPath, './entities/'),
    abis: path.resolve(outputPath, './abi/'),
  },
  migrations: {
    path: path.resolve(outputPath, './migrations/'),
    migrationName: 'InitialSchema',
    schemaName: 'SQL_SCHEMA',
    schemaVariable: true,
  },
  docs: {
    path: path.resolve(outputPath, './docs/'),
  },
  contracts: {
    ComptrollerProxy: {
      abi: ComptrollerImplementation,
    },
  },
};

This generates:

• Entity classes for each event in the ABI (e.g., DistributedSupplierCompEntity_2de01bb4)
• Database migrations for creating the tables
• API documentation for the generated entities

2. ABI Merging

The example shows how to handle proxy contracts by merging the ABIs:

abi: mergeEventAbis(proxyAbi, implementationAbi);

How It Works

1. Entity Generation Process:

   • Run pnpm generate-entities to process the ABIs
   • Creates TypeORM entities in src/output/entities/
   • Generates migrations in src/output/migrations/
   • All generated entities extend BlockchainEventEntity for common fields

2. Generated Entities Include:

   • DistributedSupplierCompEntity_2de01bb4
   • DistributedBorrowerCompEntity_8bcf5026
   • Other event entities from the Comptroller contract

3. Auto-Generated Fields: Each entity automatically includes blockchain event fields like:

   • uniqueEventId
   • blockNumber
   • transactionHash
   • blockTimestamp
   • Event-specific fields from the ABI

Setup and Usage

1. Generate entities from ABIs:

pnpm generate-entities

2. Copy .env.example file to .env file and set up environment variables:

NODE_RPC_URL=<your-ethereum-node-url>
CHAIN_ID=1

3. Install dependencies:

pnpm install

4. Run the indexer:

pnpm start

The generated entities require no additional code to index events - they're automatically populated when matching events are found on-chain.