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.

I want to update my existing version v0 transformation code to version v1. What do I do?

You cannot update transformation Version: V0 directly to Version: V1. Please create a new transformation with updated code Version: V1. You can then reconnect your destinations with this new transformation that you have created and delete existing Version: V0 transformation.

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.