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Configuration

Set up the configuration files needed to run your local EVM indexer.

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Dataset Configuration

Create a config.yaml file to define your dataset:
config.yaml
my-devnet:
  kind: evm
  retention_strategy:
    FromBlock:
      number: 0
    # Alternative: retain last N blocks
    # Head: 500
  data_sources:
    - http://hotblocks-service:3000

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Configuration Options

kind
  • Set to evm for Ethereum-compatible chains
retention_strategy Choose one of two strategies:
  • FromBlock: Keep all blocks starting from the specified block number 
    FromBlock:
  number: 0  # Start from genesis
  • Head: Keep only the most recent N blocks (rolling window) 
    Head: 500  # Keep last 500 blocks
data_sources
  • Internal service URL (use http://hotblocks-service:3000 as shown)
  • This connects to the hotblocks-service container

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Docker Compose Configuration

Create a docker-compose.yaml file:
docker-compose.yaml
services:
  # Loads data from RPC and serves full blocks
  hotblocks-service:
    image: subsquid/evm-hotblocks-service:4229b9b2
    environment:
      SQD_INFO: "*"
    command: >
      --http-rpc ${RPC_URL}
      --receipts
      --traces
      --diffs
      --use-debug-api-for-statediffs
      --verify-tx-sender
      --verify-tx-root
      --verify-logs-bloom
      --block-cache-size 10
    # Optional verification flags:
    # --verify-receipts-root
    # --verify-block-hash

  # Loads full blocks from hotblocks-service and provides query API
  hotblocks-db:
    image: subsquid/data-hotblocks:a8e7c369
    environment:
      RUST_LOG: "info"
    command: >
      --datasets /app/config.yaml
      --db /run/db
      --port 8000
    ports:
      - "8000:8000"
    volumes:
      - ./config.yaml:/app/config.yaml
      - db-data:/run/db
    depends_on:
      - hotblocks-service

volumes:
  db-data:

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Service Details

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hotblocks-service

Fetches blockchain data from your RPC endpoint. Key command flags:
  • --http-rpc ${RPC_URL} - Your RPC endpoint (set via environment variable)
  • --receipts - Fetch transaction receipts
  • --traces - Fetch execution traces
  • --diffs - Fetch state diffs
  • --use-debug-api-for-statediffs - Use debug API for state diff extraction
  • --verify-tx-sender - Verify transaction sender addresses
  • --verify-tx-root - Verify transaction root hashes
  • --verify-logs-bloom - Verify logs bloom filters
  • --block-cache-size 10 - Cache 10 blocks in memory
Optional verification flags (commented out by default):
  • --verify-receipts-root - Verify receipts root hash
  • --verify-block-hash - Verify block hash
Enable additional verification flags for maximum data integrity, but note they may increase processing time.

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hotblocks-db

Stores blockchain data and exposes the query API. Configuration:
  • --datasets /app/config.yaml - Path to dataset configuration
  • --db /run/db - Database storage location
  • --port 8000 - API server port
  • Volumes:
    • ./config.yaml:/app/config.yaml - Mounts your config file
    • db-data:/run/db - Persistent storage for blockchain data
Environment:
  • RUST_LOG: "info" - Set logging level (options: error, warn, info, debug, trace)

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Storage Considerations

The db-data volume stores the entire blockchain. Disk space usage grows continuously as new blocks are added.Recommendations:
  • Monitor disk usage regularly
  • Use the Head retention strategy for development/testing
  • Ensure adequate disk space before syncing production chains

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Next Steps

Proceed to the Usage page to start the services and query your data.