[Home](./index.md) > [@datashaper/schema](./schema.md) > [BasicInput](./schema.basicinput.md)
## BasicInput interface
Single-input, single-output step I/O
Signature:
```typescript
export interface BasicInput
```
## Properties
| Property | Modifiers | Type | Description |
| --- | --- | --- | --- |
| [input?](./schema.basicinput.input.md) | | [WorkflowStepId](./schema.workflowstepid.md) \| { source: [WorkflowInput](./schema.workflowinput.md); } | (Optional) Standard step input; single source with default name "source".
If undefined, the default output of the previous step will be used (if available). If no previous step is available, this will remain undefined
|