> * Method: `withOutputPreProcessor(outputPreProcessor)`
> * Type: `LangServeOutputPreProcessor`
> * Usage:

```tsx
// Example: We check for a number and we format it before returning it to the user a string
const myOutputPreProcessor: LangServeOutputPreProcessor = (output: any) => {
    if (output.value > 1000000000) {
        return 'Too big!';
    }

    return output.value.toString(
        output.base === 2 ? 2 : 10
    );
};

const adapter = createChatAdapter()
    .withUrl('https://<My LangServe Runnable URL>')
    .withOutputPreProcessor(myOutputPreProcessor);
```
