Set Variable

The Set Variable node assigns a value to a named variable. The value can be a static string or a computed expression.

Behavior

Parameter	Type	Default	Options	Description
`variableName`	string	`""`	—	Name of the variable to set
`source`	enum	`"static"`	`static`, `expression`	How the value is determined
`value`	string	`""`	—	Static value (used when `source` is `static`)
`expression`	string	`""`	—	Expression to evaluate (used when `source` is `expression`)

Source	Description
`static`	Set the variable to a literal string value
`expression`	Evaluate an expression (e.g., concatenation, arithmetic, or referencing other variables)

Handle	Description
Success	Variable set successfully
Error	Failed to set variable (e.g., invalid expression)

Default values

Set language to "en" at the start of the flow. Override it later based on caller input.

Computed values

Use expression source to combine variables: set greeting to "Hello, " + {{customer_name}}.

Flow state tracking

Set a status variable at different points in the flow (e.g., "verified", "transferred") for use in API calls or logging.