Expression Language is a special syntax used in Blue Relay to dynamically evaluate and manipulate data at runtime.

In the context of Workflows and Events - it utilizes Spring Expression Language (SpEL)

In the context of Form questions - it utilizes Angular Expressions.


This article will mostly cover SpEL.



It allows you to:

  • Inject values into fields
  • Access object properties
  • Query and retrieve data
  • Apply logic and conditions
  • Transform or combine values

It is commonly used across:

  • Events (triggers and actions)
  • Workflows and tasks
  • Forms (including question rules)
  • Filters and conditions

In simple terms, Expression Language lets you make the rules of an automation dynamic instead of static.

Key Concept

Expressions are evaluated when the system runs, not when they are written.

For example:

(( #file.title ))

This will resolve to the actual file title at runtime, depending on the current context.

Types of Available Data

Expression Language works with three main types of data:

  • Always Available Data
    (e.g., #user, #company, #item)

  • Helper / Utility Functions
    (e.g., #expr, #list, #map)

  • Contextual Data
    (depends on where the expression is used)



See <> for more details