> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sqd.dev/llms.txt
> Use this file to discover all available pages before exploring further.

<AgentInstructions>

## Submitting Feedback

If you encounter incorrect, outdated, or confusing documentation on this page, submit feedback:

POST https://docs.sqd.dev/feedback

```json
{
  "path": "/en/sdk/squid-sdk/reference/frontier",
  "feedback": "Description of the issue"
}
```

Only submit feedback when you have something specific and actionable to report.

</AgentInstructions>

# The frontier package

> Index EVMs running on Substrate (Frontier) with Squid SDK — use the @subsquid/frontier package to decode Frontier-EVM events and contract calls.

# `@subsquid/frontier`

The way the Frontier EVM pallet exposes EVM logs and transaction may change due to runtime upgrades. [`@subsquid/frontier`](https://github.com/subsquid/squid-sdk/tree/master/substrate/frontier) provides helper methods that are aware of the upgrades:

#### `getEvmLog(event: Event): EvmLog`

Extract the EVM log data from `EVM.Log` event.

#### `getTransaction(call: Call): LegacyTransaction | EIP2930Transaction | EIP1559Transaction`

Extract the transaction data from `Ethereum.transact` call with additional fields depending on the EVM transaction type.

#### `getTransactionResult(ethereumExecuted: Event): {from: string, to: string, transactionHash: string, status: 'Succeed' | 'Error' | 'Revert' | 'Fatal', statusReason: string}`

Extract transaction result from an `Ethereum.Executed` event.

See also the [Frontier EVM guide](/en/sdk/squid-sdk/resources/substrate/frontier-evm).

#### Example

```typescript theme={"system"}
const processor = new SubstrateBatchProcessor()
  .setGateway('https://v2.archive.subsquid.io/network/astar-substrate')
  .setRpcEndpoint('https://astar-rpc.dwellir.com')
  .addEthereumTransaction({})
  .addEvmLog({})

processor.run(new TypeormDatabase(), async ctx => {
  for (const block of ctx.blocks) {
    for (const event of block.events) {
      if (event.name === 'EVM.Log') {
        // no need to supply any extra data to determine
        // the runtime version: event has all necessary references
        const {address, data, topics} = getEvmLog(event)

        // process evm log data
      }
    }
    for (const call of block.calls) {
      if (call.name==='Ethereum.transact') {
        const txn = getTransaction(call)
        // process evm txn data
      }   
    }
  }
})
```