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Arcanflows

Variables

Store and manage data throughout your workflow

Variables store and manage data throughout your workflow execution.

Variable Types

Input Variables

Data passed to the workflow when it starts:

javascript
// Access trigger input data
{{ input.customer_id }}
{{ input.data.email }}
{{ input.headers['x-custom-header'] }}

Node Output Variables

Results from previous nodes:

javascript
// Access node outputs by node name
{{ nodes.http_request_1.response.body }}
{{ nodes.ai_agent.response.content }}
{{ nodes.database_query.rows[0].name }}

Workflow Variables

Custom variables you define:

javascript
// Set in a Set Variables node
{{ variables.order_total }}
{{ variables.is_premium }}
{{ variables.retry_count }}

System Variables

Built-in variables available everywhere:

javascript
{{ workflow.id }}           // Current workflow ID
{{ workflow.name }}         // Workflow name
{{ execution.id }}          // Current execution ID
{{ execution.started_at }}  // Execution start time
{{ tenant.id }}             // Tenant ID
{{ now() }}                 // Current timestamp

Setting Variables

Set Variables Node

json
{
  "type": "set_variables",
  "variables": {
    "order_total": "{{ nodes.calculate.result.total }}",
    "is_premium": "{{ input.customer.tier == 'premium' }}",
    "items_count": "{{ input.items.length }}",
    "timestamp": "{{ now() }}"
  }
}

Increment/Decrement

json
{
  "type": "set_variables",
  "variables": {
    "retry_count": "{{ variables.retry_count + 1 }}",
    "remaining": "{{ variables.remaining - 1 }}"
  }
}

Conditional Assignment

json
{
  "type": "set_variables",
  "variables": {
    "discount": "{{ input.amount > 1000 ? 0.1 : 0.05 }}",
    "status": "{{ nodes.api.response.success ? 'completed' : 'failed' }}"
  }
}

Variable Scope

Global Scope

Variables available throughout the entire workflow:

[Trigger] → [Set Variables] → [Action 1] → [Action 2]
     │            │                │             │
     └── input    └── variables    └── Both      └── Both

Loop Scope

Variables specific to loop iterations:

javascript
// Inside a loop
{{ loop.item }}        // Current item
{{ loop.index }}       // Current index (0-based)
{{ loop.is_first }}    // True if first iteration
{{ loop.is_last }}     // True if last iteration
{{ loop.length }}      // Total items

Branch Scope

Variables from parallel branches:

javascript
// After a merge node
{{ branches.branch_1.result }}
{{ branches.branch_2.result }}

Expression Syntax

Basic Operations

javascript
// Arithmetic
{{ input.price * input.quantity }}
{{ variables.total + 10 }}
{{ input.amount / 100 }}

// String concatenation
{{ input.first_name + ' ' + input.last_name }}
{{ 'Order #' + input.order_id }}

// Comparisons
{{ input.amount > 100 }}
{{ input.status == 'active' }}
{{ input.email != null }}

Array Operations

javascript
// Access by index
{{ input.items[0] }}
{{ input.items[input.items.length - 1] }}

// Array methods
{{ input.items.length }}
{{ input.items.includes('value') }}
{{ input.tags.join(', ') }}

Object Operations

javascript
// Nested access
{{ input.customer.address.city }}
{{ input.metadata['custom-key'] }}

// Optional chaining
{{ input.customer?.address?.city ?? 'Unknown' }}

Built-in Functions

FunctionDescriptionExample
now()Current timestamp{{ now() }}
uuid()Generate UUID{{ uuid() }}
json()Parse JSON string{{ json(input.data) }}
stringify()Convert to JSON{{ stringify(input.object) }}
format()Format date{{ format(now(), 'YYYY-MM-DD') }}
lower()Lowercase string{{ lower(input.email) }}
upper()Uppercase string{{ upper(input.code) }}
trim()Trim whitespace{{ trim(input.name) }}
split()Split string{{ split(input.tags, ',') }}
round()Round number{{ round(input.price, 2) }}
abs()Absolute value{{ abs(input.difference) }}
min()Minimum value{{ min(input.values) }}
max()Maximum value{{ max(input.values) }}

String Functions

javascript
// Formatting
{{ lower(input.email) }}                    // lowercase
{{ upper(input.code) }}                     // UPPERCASE
{{ capitalize(input.name) }}                // Capitalize
{{ trim(input.value) }}                     // Remove whitespace

// Manipulation
{{ replace(input.text, 'old', 'new') }}    // Replace
{{ substring(input.text, 0, 10) }}          // Substring
{{ split(input.csv, ',') }}                 // Split to array

// Testing
{{ startsWith(input.url, 'https://') }}     // Starts with
{{ endsWith(input.email, '@gmail.com') }}   // Ends with
{{ contains(input.text, 'keyword') }}       // Contains
{{ matches(input.phone, '^\+1') }}          // Regex match

Date Functions

javascript
// Current time
{{ now() }}                                 // ISO timestamp
{{ timestamp() }}                           // Unix timestamp

// Formatting
{{ format(now(), 'YYYY-MM-DD') }}          // 2025-01-15
{{ format(now(), 'HH:mm:ss') }}            // 14:30:00
{{ format(now(), 'MMMM D, YYYY') }}        // January 15, 2025

// Calculations
{{ addDays(now(), 7) }}                    // Add 7 days
{{ addHours(now(), 24) }}                  // Add 24 hours
{{ diffDays(date1, date2) }}               // Days between dates

// Parsing
{{ parseDate(input.date, 'MM/DD/YYYY') }}  // Parse custom format

Conditional Expressions

javascript
// Ternary operator
{{ input.amount > 100 ? 'premium' : 'standard' }}

// Null coalescing
{{ input.name ?? 'Unknown' }}

// Logical operators
{{ input.active && input.verified }}
{{ input.status == 'pending' || input.status == 'review' }}
{{ !input.disabled }}

Data Transformation

Map Transform

json
{
  "type": "transform",
  "operation": "map",
  "source": "{{ input.users }}",
  "transform": {
    "id": "{{ item.id }}",
    "full_name": "{{ item.first_name }} {{ item.last_name }}",
    "email_domain": "{{ split(item.email, '@')[1] }}"
  }
}

Filter Transform

json
{
  "type": "transform",
  "operation": "filter",
  "source": "{{ input.orders }}",
  "condition": "{{ item.total > 100 && item.status == 'pending' }}"
}

Reduce Transform

json
{
  "type": "transform",
  "operation": "reduce",
  "source": "{{ input.items }}",
  "initial": 0,
  "expression": "{{ accumulator + item.price * item.quantity }}"
}

Variable Picker UI

Using the Variable Picker

  1. Click in any input field
  2. Click the {{}} button or press Ctrl/Cmd + Space
  3. Browse available variables by category
  4. Click to insert or type to filter
  5. Press Enter to select

Variable Categories

CategoryIconDescription
Input↓Trigger input data
Nodes◆Previous node outputs
VariablesxWorkflow variables
System⚙System variables
FunctionsfBuilt-in functions

Autocomplete

The variable picker provides:

  • Type hints: Shows expected data types
  • Sample values: Preview of actual data
  • Documentation: Description of each variable
  • Recent: Recently used variables

Best Practices

Naming Conventions

javascript
// Good - descriptive names
{{ variables.order_total }}
{{ variables.customer_email }}
{{ variables.retry_count }}

// Avoid - unclear names
{{ variables.x }}
{{ variables.temp }}
{{ variables.data }}

Null Safety

javascript
// Always handle potential nulls
{{ input.customer?.name ?? 'Guest' }}
{{ input.items?.length ?? 0 }}
{{ input.metadata?.custom ?? {} }}

Type Conversion

javascript
// String to number
{{ parseInt(input.quantity) }}
{{ parseFloat(input.price) }}

// Number to string
{{ String(input.id) }}
{{ input.amount.toString() }}

// Boolean conversion
{{ Boolean(input.value) }}
{{ !!input.enabled }}

Complex Expressions

For complex logic, use Execute Code node:

json
{
  "type": "execute_code",
  "language": "javascript",
  "code": "const items = input.items.filter(i => i.active); const total = items.reduce((sum, i) => sum + i.price, 0); return { items, total, count: items.length };"
}

Debugging Variables

View Variable Values

  1. Run workflow in debug mode
  2. Click on any node
  3. View "Variables" tab in debug panel
  4. See all available variables at that point

Log Variables

json
{
  "type": "execute_code",
  "code": "console.log('Current variables:', { input, variables, nodes }); return input;"
}

Variable Inspector

The debug panel shows:

  • Variable name and path
  • Current value
  • Data type
  • Source (input, node, or set)

Next Steps