Variable Assigner Node

The Variable Assigner node allows you to modify the values of global or loop variables in your workflow, affecting the execution of subsequent nodes. This node provides a flexible way to manage state and data flow throughout your workflow execution.

Use Cases

Typical Applications

State Management - Update global variables to track workflow state
Loop Variable Modification - Modify loop variables during iteration
Counter Management - Increment or decrement counters based on conditions
Data Accumulation - Collect and aggregate data across multiple workflow executions
Conditional Updates - Update variables based on conditional logic
Configuration Updates - Dynamically adjust workflow configuration values
Batch Processing - Track progress and status in batch operations

Node Configuration

Basic Settings (Parameters Panel)

Variable Assignments (items)

Define variable assignments to execute. This is an array parameter where each item represents one variable assignment.

Field Properties:

Array type, can add multiple assignments
Each assignment contains:
- variable - Variable name (required)
- value - Variable value (required, supports expressions)
Assignments execute in order
Defaults to empty array

Variable Types:

Global Variables - Available throughout the entire workflow
Loop Variables - Available only within the loop node scope (when node is inside a loop)

Configuration Examples:

javascript

// Assignment 1: Set a global counter
variable: "counter"
value: 0

// Assignment 2: Update user status
variable: "userStatus"
value: $('HTTP Request').body.status

// Assignment 3: Increment counter using expression
variable: "pageNumber"
value: $('Variable Assigner').pageNumber + 1

// Assignment 4: Set from previous node output
variable: "lastProcessedId"
value: $('Code').lastId

Variable Selection

When selecting a variable, the node automatically detects whether you're inside a loop node:

Inside Loop Node: Shows loop variables from the parent loop node
Outside Loop Node: Shows only global variables

Note: The node displays a hint when assigning to loop variables, showing which loop node the variables belong to.

Value Input

The value field supports both fixed values and expressions:

Fixed Value:

javascript

// String
"Hello World"

// Number
42

// Boolean
true

// Null
null

Expression Mode:

javascript

// Reference upstream node data
$('Chat Trigger').message

// Mathematical operations
$('Code').count * 2

// String concatenation
"User: " + $('HTTP Request').body.username

// Conditional assignment
$('Conditional Branch').isValid ? "valid" : "invalid"

// Array/object operations
$('Code').items.length

Advanced Settings (Settings Panel)

Always Output (alwaysOutput)

Whether to output an empty item when output is empty.

Default: false

Purpose: Prevents workflow from terminating at this node, ensuring subsequent nodes can execute.

Execute Once (executeOnce)

Whether to execute only once using data from the first input item.

Default: false

Purpose:

When upstream nodes return multiple items, assignments execute for each item by default
When enabled, only the first item executes, improving performance for batch operations

Retry on Fail (retryOnFail)

Whether to automatically retry when variable assignment fails.

Default: false

Max Tries (maxTries)

Maximum number of retries after failure.

Default: 3

Prerequisite: retryOnFail must be true

Wait Between Tries (waitBetweenTries)

Wait time between retries (milliseconds).

Default: 1000 (1 second)

Prerequisite: retryOnFail must be true

Error Handling (onError)

How to handle variable assignment failures.

Available Values:

stopWorkflow - Stop entire workflow (default)
continueRegularOutput - Continue with regular output
continueErrorOutput - Continue with error output

Node Description (nodeDescription)

Add custom description for the node.

yaml

nodeDescription: "Update user counter and status"

Output Data

The Variable Assigner node passes through input data unchanged, allowing subsequent nodes to access the updated variables.

javascript

// Input data
{
  userId: "user123",
  message: "Hello"
}

// Output after assignment (same data, but variables updated)
{
  userId: "user123",
  message: "Hello"
}

// Updated variables are available globally
$sys.variables.counter  // Updated value
$sys.variables.userStatus  // Updated value

Accessing Updated Variables:

javascript

// In subsequent nodes, access updated variables
$sys.variables.counter
$sys.variables.userStatus

// Or reference in expressions
$('Variable Assigner').userId  // Still "user123" (unchanged)

Workflow Examples

Example 1: Counter Management

Chat Trigger
  → Variable Assigner
    Assignments:
      - variable: "messageCount"
        value: $sys.variables.messageCount + 1
  → Conditional Branch
    Condition: $sys.variables.messageCount > 10
    → [True] → Answer ("You've sent 10 messages!")
    → [False] → Answer ("Continue chatting...")

Description: Track message count and respond when threshold is reached.

Example 2: Loop Variable Updates

Loop Iterate Node (process items)
  → HTTP Request (process item)
  → Variable Assigner
    Assignments:
      - variable: "processedCount"
        value: $sys.variables.processedCount + 1
      - variable: "lastProcessedId"
        value: $('HTTP Request').body.id
  → Next iteration

Description: Track processing progress within a loop iteration.

Example 3: Conditional State Updates

HTTP Request (fetch user data)
  → Conditional Branch
    Condition: $('HTTP Request').body.status === "active"
    → [True] → Variable Assigner
      Assignments:
        - variable: "activeUserCount"
          value: $sys.variables.activeUserCount + 1
    → [False] → Variable Assigner
      Assignments:
        - variable: "inactiveUserCount"
          value: $sys.variables.inactiveUserCount + 1

Description: Update different counters based on conditional logic.

Example 4: Data Accumulation

Webhook Trigger
  → Variable Assigner
    Assignments:
      - variable: "totalRevenue"
        value: $sys.variables.totalRevenue + $('Webhook Trigger').body.amount
      - variable: "transactionCount"
        value: $sys.variables.transactionCount + 1
  → Answer Node

Description: Accumulate revenue and transaction counts across multiple webhook calls.

Example 5: Dynamic Configuration

Code Node (calculate batch size)
  → Variable Assigner
    Assignments:
      - variable: "batchSize"
        value: $('Code').optimalBatchSize
      - variable: "maxRetries"
        value: $('Code').calculatedRetries
  → Loop Iterate Node
    Uses: $sys.variables.batchSize

Description: Dynamically update configuration variables based on calculations.

Example 6: Reset Variables

Variable Assigner (reset counters)
  Assignments:
    - variable: "counter"
      value: 0
    - variable: "status"
      value: "initialized"
  → Process Workflow

Description: Reset variables to initial state before starting a new process.

Best Practices

1. Variable Naming

Use Descriptive Names

javascript

// Good
variable: "userMessageCount"
variable: "lastProcessedOrderId"
variable: "currentBatchIndex"

// Avoid
variable: "c1"
variable: "temp"
variable: "x"

Follow Naming Conventions

Use camelCase for variable names
Use descriptive names that indicate purpose
Avoid abbreviations unless widely understood

2. Initialize Variables

Set Initial Values

javascript

// At workflow start, initialize variables
Variable Assigner:
  - variable: "counter"
    value: 0
  - variable: "status"
    value: "pending"

3. Use Expressions for Dynamic Updates

Calculate Values Dynamically

javascript

// Instead of hardcoding
variable: "nextPage"
value: $sys.variables.currentPage + 1

// Use conditional logic
variable: "status"
value: $('HTTP Request').statusCode === 200 ? "success" : "failed"

4. Avoid Overwriting Unintentionally

Check Before Updating

javascript

// Use conditional logic to prevent unwanted overwrites
variable: "lastProcessedId"
value: $('HTTP Request').body.id || $sys.variables.lastProcessedId

5. Document Variable Usage

Add Node Descriptions

yaml

nodeDescription: "Update user counter and track last processed message ID"

6. Performance Considerations

Use Execute Once for Batch Operations

yaml

# When processing multiple items, update counter once
settings:
  executeOnce: true

Minimize Variable Updates

Only update variables when necessary
Consider combining multiple updates into single assignments

7. Error Handling

Handle Assignment Failures

yaml

settings:
  onError: continueRegularOutput  # Continue even if assignment fails
  retryOnFail: true
  maxTries: 3

FAQ

Q1: What's the difference between global and loop variables?

Global Variables: Available throughout the entire workflow, persist across all nodes
Loop Variables: Available only within the scope of a loop node, reset for each iteration

Q2: Can I assign to variables that don't exist yet?

A: Yes, assigning to a non-existent variable creates it. However, it's recommended to initialize variables at workflow start for clarity.

Q3: Can I use expressions in variable names?

A: No, variable names must be fixed strings. Only the value supports expressions.

Q4: What happens if I assign to the same variable multiple times in one node?

A: Assignments execute in order, so later assignments overwrite earlier ones for the same variable.

Q5: Can variables be accessed across different workflow executions?

A: Global variables persist during a single workflow execution but are reset between executions. For persistent storage, use external storage systems.

Q6: How do I clear or reset a variable?

A: Assign null or an empty value:

javascript

variable: "myVariable"
value: null  // or "" for strings, 0 for numbers

Q7: Can I use variables in conditional branches?

A: Yes, reference variables using $sys.variables.variableName:

javascript

$sys.variables.counter > 10
$sys.variables.status === "active"

Q8: What happens if assignment fails?

A: Based on onError setting:

stopWorkflow - Workflow stops (default)
continueRegularOutput - Continues with regular output
continueErrorOutput - Continues with error output

Q9: Can I assign complex objects or arrays?

A: Yes, variables can hold any data type:

javascript

variable: "userData"
value: $('HTTP Request').body  // Object

variable: "items"
value: $('Code').items  // Array

Q10: How do I increment a counter?

A: Use expressions to reference the current value:

javascript

variable: "counter"
value: $sys.variables.counter + 1

Next Steps

Loop & Iterate - Learn how to use loop variables
Conditional Branch - Use variables in conditional logic
Code Node - Complex variable calculations
Expression Syntax - Learn how to use expressions in variable values

Working with Nodes - General node usage guide
Editing Nodes - Learn how to configure nodes

Chat Trigger

Variable Assigner Node ​

Use Cases ​

Typical Applications ​

Node Configuration ​

Basic Settings (Parameters Panel) ​

Variable Assignments (items) ​

Variable Selection ​

Value Input ​

Advanced Settings (Settings Panel) ​

Always Output (alwaysOutput) ​

Execute Once (executeOnce) ​

Retry on Fail (retryOnFail) ​

Max Tries (maxTries) ​

Wait Between Tries (waitBetweenTries) ​

Error Handling (onError) ​

Node Description (nodeDescription) ​

Output Data ​

Workflow Examples ​

Example 1: Counter Management ​

Example 2: Loop Variable Updates ​

Example 3: Conditional State Updates ​

Example 4: Data Accumulation ​

Example 5: Dynamic Configuration ​

Example 6: Reset Variables ​

Best Practices ​

1. Variable Naming ​

2. Initialize Variables ​

3. Use Expressions for Dynamic Updates ​

4. Avoid Overwriting Unintentionally ​

5. Document Variable Usage ​

6. Performance Considerations ​

7. Error Handling ​

FAQ ​

Q1: What's the difference between global and loop variables? ​

Q2: Can I assign to variables that don't exist yet? ​

Q3: Can I use expressions in variable names? ​

Q4: What happens if I assign to the same variable multiple times in one node? ​

Q5: Can variables be accessed across different workflow executions? ​

Q6: How do I clear or reset a variable? ​

Q7: Can I use variables in conditional branches? ​

Q8: What happens if assignment fails? ​

Q9: Can I assign complex objects or arrays? ​

Q10: How do I increment a counter? ​

Next Steps ​

Related Resources ​

Variable Assigner Node

Use Cases

Typical Applications

Node Configuration

Basic Settings (Parameters Panel)

Variable Assignments (items)

Variable Selection

Value Input

Advanced Settings (Settings Panel)

Always Output (alwaysOutput)

Execute Once (executeOnce)

Retry on Fail (retryOnFail)

Max Tries (maxTries)

Wait Between Tries (waitBetweenTries)

Error Handling (onError)

Node Description (nodeDescription)

Output Data

Workflow Examples

Example 1: Counter Management

Example 2: Loop Variable Updates

Example 3: Conditional State Updates

Example 4: Data Accumulation

Example 5: Dynamic Configuration

Example 6: Reset Variables

Best Practices

1. Variable Naming

2. Initialize Variables

3. Use Expressions for Dynamic Updates

4. Avoid Overwriting Unintentionally

5. Document Variable Usage

6. Performance Considerations

7. Error Handling

FAQ

Q1: What's the difference between global and loop variables?

Q2: Can I assign to variables that don't exist yet?

Q3: Can I use expressions in variable names?

Q4: What happens if I assign to the same variable multiple times in one node?

Q5: Can variables be accessed across different workflow executions?

Q6: How do I clear or reset a variable?

Q7: Can I use variables in conditional branches?

Q8: What happens if assignment fails?

Q9: Can I assign complex objects or arrays?

Q10: How do I increment a counter?

Next Steps

Related Resources