> For the complete documentation index, see [llms.txt](https://docs.envio.dev/llms.txt).

# Local chain - Hardhat

---

A local chain can be used as a data source for your indexer. You simply need to specify it in `config.yaml`.

### Defining Chain Configurations

```yaml
name: IndexerName # Specify indexer name
description: Indexer Description # Include indexer description
chains:
  - id: 31337 # Local Hardhat default chain id
    rpc: http://localhost:8545 # RPC URL for your local Hardhat chain
    start_block: START_BLOCK_NUMBER # Specify the starting block
    contracts:
      - name: ContractName
        address:
          - "0xYourContractAddress1"
          - "0xYourContractAddress2"
        events:
          - event: Event # Specify event
          - event: Event
```

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