FAQ

Commonly asked questions about RudderStack's Transformations feature.

This document contains some of the commonly asked questions regarding RudderStack's Transformations feature.

Why do I need to use RudderStack's Transformations feature?

RudderStack's Transformations feature lets you transform the events collected from a source into a destination-specific format. Some key benefits of this feature are:

  • These transformations can be applied to your in-transit events, in real-time.

  • You can implement specific use-cases depending on your business requirements using this feature. Some examples include PII masking, event filtering based on specific criteria, aggregating and enriching events, and so on.

  • They're easier to build and manage, and can be reused as well.

Read more about why your data pipeline needs to have an efficient event transformations capability in our blog.

I used to write transformations like function transform(events) {}. Why am I not able to create new transformations this way?

We have changed the way transformations are written. RudderStack now supports writing functions that transform a single event instead of a batch of events. You can now define your transformation in the following manner:

export function transformEvent(event, metadata) {}

I want to write a transformation that can be applied to a small batch of events. Can I not do this anymore?

You can. Simply define your transformation in the following manner:

export function transformBatch(event, metadata) {} .

This can cause a loss of the event metadata that RudderStack uses internally to maintain event ordering for you.

I cannot import libraries into my existing transformations. What do I do?

Previously created transformations shown as Version: V0 don't support libraries. If you want to use libraries, please create a new transformation with Version: V1 that support libraries. You can then reconnect your destinations with this new transformation that you have created.

Contact Us

For more information on transformations and libraries in RudderStack, feel free to contact us. You can also talk to us on our Slack channel.