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

# LogIndex

> Log position in receipt (0-based)

## Overview

LogIndex is a branded `number` type representing a log's position within a transaction receipt. Indices start at 0 for the first log emitted.

```typescript theme={null}
import * as LogIndex from '@tevm/primitives/LogIndex'

const index = LogIndex.from(2)
```

## Type Definition

```typescript theme={null}
type LogIndexType = number & {
  readonly [brand]: "LogIndex";
}
```

## Creating LogIndexes

### from

Create from number or bigint.

```typescript theme={null}
// From number
const idx1 = LogIndex.from(2)

// From bigint
const idx2 = LogIndex.from(2n)

// First log
const first = LogIndex.from(0)
```

**Validation**: Must be non-negative integer.

## Converting LogIndexes

### toNumber

Convert to number (zero-cost).

```typescript theme={null}
const num = LogIndex.toNumber(index)
// 2
```

## Comparing LogIndexes

### equals

Check equality.

```typescript theme={null}
const a = LogIndex.from(2)
const b = LogIndex.from(2)

if (LogIndex.equals(a, b)) {
  console.log('Indexes are equal')
}
```

## Usage in Event Logs

LogIndex appears in event logs to indicate position within a receipt:

```typescript theme={null}
import * as EventLog from '@tevm/primitives/EventLog'

const log = {
  logIndex: LogIndex.from(2),
  address: contractAddress,
  topics: [eventSignature],
  data: eventData
}
```

## Errors

**InvalidLogIndexError**: Invalid value (negative, non-integer, wrong type).

## See Also

* [EventLog](/primitives/eventlog) - Event logs
* [Receipt](/primitives/receipt) - Transaction receipts
* [TransactionIndex](/primitives/transaction-index) - Transaction position