> ## 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.

# primitives/OpStep

> Auto-generated API documentation

[**@tevm/voltaire**](../index.mdx)

***

[@tevm/voltaire](../index.mdx) / primitives/OpStep

# primitives/OpStep

## Type Aliases

### OpStepType

> **OpStepType** = `object`

Defined in: [src/primitives/OpStep/OpStepType.ts:12](https://github.com/evmts/voltaire/blob/bd6ec34405c15ad8cd51d11579d495dc53813482/src/primitives/OpStep/OpStepType.ts#L12)

Single opcode execution step
Represents the EVM state at a specific instruction

#### See

[https://voltaire.tevm.sh/primitives/op-step](https://voltaire.tevm.sh/primitives/op-step) for OpStep documentation

#### Since

0.0.0

#### Properties

##### \[brand]

> `readonly` **\[brand]**: `"OpStep"`

Defined in: [src/primitives/OpStep/OpStepType.ts:13](https://github.com/evmts/voltaire/blob/bd6ec34405c15ad8cd51d11579d495dc53813482/src/primitives/OpStep/OpStepType.ts#L13)

##### depth

> `readonly` **depth**: `number`

Defined in: [src/primitives/OpStep/OpStepType.ts:23](https://github.com/evmts/voltaire/blob/bd6ec34405c15ad8cd51d11579d495dc53813482/src/primitives/OpStep/OpStepType.ts#L23)

Call depth (0 for top-level call)

##### error?

> `readonly` `optional` **error**: `string`

Defined in: [src/primitives/OpStep/OpStepType.ts:31](https://github.com/evmts/voltaire/blob/bd6ec34405c15ad8cd51d11579d495dc53813482/src/primitives/OpStep/OpStepType.ts#L31)

Error message if step failed

##### gas

> `readonly` **gas**: [`Type`](Uint.mdx#type)

Defined in: [src/primitives/OpStep/OpStepType.ts:19](https://github.com/evmts/voltaire/blob/bd6ec34405c15ad8cd51d11579d495dc53813482/src/primitives/OpStep/OpStepType.ts#L19)

Remaining gas before executing this operation

##### gasCost

> `readonly` **gasCost**: [`Type`](Uint.mdx#type)

Defined in: [src/primitives/OpStep/OpStepType.ts:21](https://github.com/evmts/voltaire/blob/bd6ec34405c15ad8cd51d11579d495dc53813482/src/primitives/OpStep/OpStepType.ts#L21)

Gas cost for this operation

##### memory?

> `readonly` `optional` **memory**: `Uint8Array`

Defined in: [src/primitives/OpStep/OpStepType.ts:27](https://github.com/evmts/voltaire/blob/bd6ec34405c15ad8cd51d11579d495dc53813482/src/primitives/OpStep/OpStepType.ts#L27)

Memory state (raw bytes)

##### op

> `readonly` **op**: [`BrandedOpcode`](Opcode.mdx#brandedopcode)

Defined in: [src/primitives/OpStep/OpStepType.ts:17](https://github.com/evmts/voltaire/blob/bd6ec34405c15ad8cd51d11579d495dc53813482/src/primitives/OpStep/OpStepType.ts#L17)

Opcode number (0x00-0xFF)

##### pc

> `readonly` **pc**: `number`

Defined in: [src/primitives/OpStep/OpStepType.ts:15](https://github.com/evmts/voltaire/blob/bd6ec34405c15ad8cd51d11579d495dc53813482/src/primitives/OpStep/OpStepType.ts#L15)

Program counter (bytecode offset)

##### stack?

> `readonly` `optional` **stack**: readonly [`Type`](Uint.mdx#type)\[]

Defined in: [src/primitives/OpStep/OpStepType.ts:25](https://github.com/evmts/voltaire/blob/bd6ec34405c15ad8cd51d11579d495dc53813482/src/primitives/OpStep/OpStepType.ts#L25)

Stack state (top to bottom)

##### storage?

> `readonly` `optional` **storage**: `Record`\<`string`, [`Type`](Uint.mdx#type)>

Defined in: [src/primitives/OpStep/OpStepType.ts:29](https://github.com/evmts/voltaire/blob/bd6ec34405c15ad8cd51d11579d495dc53813482/src/primitives/OpStep/OpStepType.ts#L29)

Storage changes in this step (key -> value)

## Functions

### \_from()

> **\_from**(`data`): [`OpStepType`](#opsteptype)

Defined in: [src/primitives/OpStep/from.js:21](https://github.com/evmts/voltaire/blob/bd6ec34405c15ad8cd51d11579d495dc53813482/src/primitives/OpStep/from.js#L21)

Creates an OpStep from raw data

#### Parameters

##### data

OpStep data

###### depth

`number`

Call depth

###### error?

`string`

Error message

###### gas

[`Type`](Uint.mdx#type)

Remaining gas

###### gasCost

[`Type`](Uint.mdx#type)

Gas cost

###### memory?

`Uint8Array`\<`ArrayBufferLike`>

Memory state

###### op

[`BrandedOpcode`](Opcode.mdx#brandedopcode)

Opcode

###### pc

`number`

Program counter

###### stack?

readonly [`Type`](Uint.mdx#type)\[]

Stack state

###### storage?

`Record`\<`string`, [`Type`](Uint.mdx#type)>

Storage changes

#### Returns

[`OpStepType`](#opsteptype)

OpStep instance

#### Example

```javascript theme={null}
import { from } from './from.js';
const step = from({ pc: 0, op: 0x60, gas: 1000000n, gasCost: 3n, depth: 0 });
```

***

### \_hasError()

> **\_hasError**(`step`): `boolean`

Defined in: [src/primitives/OpStep/hasError.js:14](https://github.com/evmts/voltaire/blob/bd6ec34405c15ad8cd51d11579d495dc53813482/src/primitives/OpStep/hasError.js#L14)

Checks if an OpStep has an error

#### Parameters

##### step

[`OpStepType`](#opsteptype)

OpStep to check

#### Returns

`boolean`

True if step has an error

#### Example

```javascript theme={null}
import { hasError } from './hasError.js';
if (hasError(step)) {
  console.error(`Error at PC ${step.pc}: ${step.error}`);
}
```

***

### from()

> **from**(`data`): [`OpStepType`](#opsteptype)

Defined in: [src/primitives/OpStep/index.ts:22](https://github.com/evmts/voltaire/blob/bd6ec34405c15ad8cd51d11579d495dc53813482/src/primitives/OpStep/index.ts#L22)

Creates an OpStep from raw data

#### Parameters

##### data

`Omit`\<[`OpStepType`](#opsteptype), `brand`>

OpStep data

#### Returns

[`OpStepType`](#opsteptype)

OpStep instance

#### See

[https://voltaire.tevm.sh/primitives/op-step](https://voltaire.tevm.sh/primitives/op-step) for OpStep documentation

#### Since

0.0.0

#### Example

```typescript theme={null}
import { OpStep } from './primitives/OpStep/index.js';
const step = OpStep.from({ pc: 0, op: 0x60, gas: 1000000n, gasCost: 3n, depth: 0 });
```

***

### hasError()

> **hasError**(`step`): `boolean`

Defined in: [src/primitives/OpStep/index.ts:41](https://github.com/evmts/voltaire/blob/bd6ec34405c15ad8cd51d11579d495dc53813482/src/primitives/OpStep/index.ts#L41)

Checks if an OpStep has an error

#### Parameters

##### step

[`OpStepType`](#opsteptype)

OpStep to check

#### Returns

`boolean`

True if step has an error

#### Example

```typescript theme={null}
import { OpStep } from './primitives/OpStep/index.js';
if (OpStep.hasError(step)) {
  console.error(`Error: ${step.error}`);
}
```