# withTransformClientCertHeader

- Module: [Aspire.Hosting.Yarp](/reference/api/typescript/aspire.hosting.yarp.md)
- Version: `13.4.0`
- Kind: `method`
- Source: [GitHub](https://github.com/microsoft/aspire)

Adds the transform which will set the given header with the Base64 encoded client certificate.

## Definition

```typescript
interface YarpRoute {
  // ... omitted for brevity
  withTransformClientCertHeader(headerName: string): YarpRoute
}
```

## Parameters

- `headerName` (`string`)

## Returns

[YarpRoute](/reference/api/typescript/aspire.hosting.yarp/yarproute.md)

## Applies to

- [YarpRoute](/reference/api/typescript/aspire.hosting.yarp/yarproute.md)