LiquidJS and Functions Unsupported in Reverse ETL Destinations – Twilio Support

Issue

When configuring a destination mapping in Segment Reverse ETL (RETL), you may find that LiquidJS syntax (such as filters like default) and functions (such as coalesce, lower, or uppercase) do not work as expected. The mapping interface only accepts simple field references, and advanced logic is ignored.

Product

Twilio Segment

Environment

Segment Console

Cause

Segment Reverse ETL mappings do not support LiquidJS syntax or functions. The mapping interface for RETL destinations differs from other standard destinations and does not process advanced LiquidJS expressions.

Resolution

To implement fallback logic or advanced transformations for Reverse ETL destinations, handle these requirements directly within your source data warehouse before sending data to Segment:

Perform fallback logic, string formatting, and conditional transformations in your data warehouse using SQL (for example, applying COALESCE or string manipulation functions in Snowflake or BigQuery).
Map the pre-transformed SQL query output fields directly to your Segment RETL destination mapping.

Additional Information

The UI for RETL mappings does not include a function dropdown or support for LiquidJS expressions.
For more details on supported liquid features, refer to the Segment documentation on Liquid Syntax.
For further guidance on data modeling, consult your internal data engineering team or Segment Professional Services.