# DockerfileBuilder.arg

- Module: [Aspire.Hosting](/reference/api/typescript/aspire.hosting.md)
- Defined on: [DockerfileBuilder](/reference/api/typescript/aspire.hosting/dockerfilebuilder.md)
- Version: `13.3.0`
- Kind: `method`

Adds a global ARG statement to the Dockerfile

## Definition

```typescript
interface DockerfileBuilder {
  // ... omitted for brevity
  arg(
      name: string,
      defaultValue?: string): DockerfileBuilder;
}
```

## Signature

```typescript
arg(
    name: string,
    defaultValue?: string): DockerfileBuilder
```

## Parameters

- `name` (`string`)
- `defaultValue` (`string`) `optional`

## Returns

[DockerfileBuilder](/reference/api/typescript/aspire.hosting/dockerfilebuilder.md)

## Defined on

- [DockerfileBuilder](/reference/api/typescript/aspire.hosting/dockerfilebuilder.md) -- `handle`