# Evm.setBalIndex

Sets the block access index reads resolve at and writes record under.

Index `0` is the pre-execution state, and transaction `i` uses index `i + 1`.

## Imports

:::code-group
```ts [Named]
import { Evm } from 'ox/evm'
```

```ts [Entrypoint]
import * as Evm from 'ox/evm/Evm'
```
:::

## Examples

```ts twoslash
// @noErrors
import { Evm } from 'ox/evm'

Evm.setBalIndex(evm, 1n)
```

## Definition

```ts
function setBalIndex<asynchronous>(
  evm: Evm<asynchronous>,
  index: bigint,
): Awaitable<asynchronous, void>
```

**Source:** [src/evm/Evm.ts](https://github.com/wevm/ox/blob/main/src/evm/Evm.ts#L1061)

## Parameters

### evm

* **Type:** `Evm<asynchronous>`

EVM to position.

#### evm.'~async'

* **Type:** `asynchronous`

#### evm.'~chainId'

* **Type:** `bigint`

#### evm.'~config'

* **Type:** `{ block: Block; specId: "frontier" | "homestead" | "tangerine" | "spuriousDragon" | "byzantium" | "petersburg" | "istanbul" | "berlin" | "london" | "merge" | "shanghai" | "cancun" | "prague" | "osaka" | "amsterdam"; version?: Version; }`

The engine's current execution config.

Held so a setter can replace one half without discarding the other, since
the adapter's operation carries both.

#### evm.'~driver'

* **Type:** `asynchronous extends true ? Driver : undefined`

Drives the asynchronous source, when there is one.

#### evm.'~engine'

* **Type:** `Engine`

#### evm.block

* **Type:** `Block`

#### evm.specId

* **Type:** `"frontier" | "homestead" | "tangerine" | "spuriousDragon" | "byzantium" | "petersburg" | "istanbul" | "berlin" | "london" | "merge" | "shanghai" | "cancun" | "prague" | "osaka" | "amsterdam"`

#### evm.version

* **Type:** `Version`
* **Optional**

### index

* **Type:** `bigint`

Index to use.

## Return Type

`Awaitable<asynchronous, void>`