Template Interpolation Agent, Say Node & Menu Node

Template Interpolation

Text fields (Say, Agent, Menu prompts) use {{expression}} interpolation:

Syntax	Purpose	Example
{{expression}}	Variable lookup or expression	Hello {{name}}, you have {{items.length}} items

• {{expression}} — evaluated by the Expression Engine, matches the next }}

• Simple variable names like {{name}} resolve to a variable lookup

• Complex expressions like {{items.filter(x => x.active).length}} are fully evaluated

• The double-brace delimiter avoids collision with JSON content in system prompts

• Non-printable results (objects, arrays) are JSON-stringified; null/undefined produce empty string

• Errors preserve the original text and log a warning

What Template Interpolation Means in an Agent Node, Say Node and Menu Node

• Configure an Agent Node

• Inside the System Prompt field, you typed: Testing {{

• As soon as {{ is typed, a template helper dropdown appears

• The dropdown lists:

  • Variables (var boolean, var number, var userEndpoint, etc.)

  • Slots from Test (agent node) (example tooltip: Variable – boolean)

  • Built‑in functions (fn $addDays, fn $format, fn $now, etc.)

  • JS native objects/functions (Date, Math, parseInt, String, etc.)

This confirms that the System Prompt supports template interpolation using {{ }} syntax, with access to typed variables and runtime helpers.