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Assertion Node

Quick Reference

NameDescription
Fleak Eval QueryWrite a FEEL statement to verify data quality and enforce constraints on incoming events. Result must be boolean.

💡 Tip: You can use learn more about FEEL (Fleak EVAL) here.

Overview

The assertion node is a validation component in your ZephFlow pipeline that allows you to verify data quality and enforce constraints on incoming events. It evaluates each event against conditions written in the Fleak Eval Expression Language (FEEL) and explicitly handles validation failures.

If the expression evaluates to true: The event passes validation and continues through the pipeline

If the expression evaluates to anything other than true: An error is generated and the event is routed to error handling (Dead Letter Queue if configured)

Fleak Eval Query

This is the main input field where you define your logic in FEEL (Fleak Eval Expression Language), a standard notation designed to perform data manipulation. For a complete guide on available functions and operators, please refer to the official Fleak FEEL Reference Guide.

  • eval: Transform events using the same expression language
  • filter: Drop events based on specific conditions using FEEL