Variable Assigner

Manage persistent conversation variables in Chatflow applications

The Variable Assigner node manages persistent data in Chatflow applications by writing to conversation variables (Understand the different types of variables here). Unlike regular workflow variables that reset with each execution, conversation variables persist throughout an entire chat session.

Variable Assigner Node Configuration

Conversation Variables vs Workflow Variables

Workflow Variables exist only during a single workflow execution and reset when the workflow completes.

Conversation Variables persist across multiple conversation turns within the same chat session, enabling stateful interactions and contextual memory.

This persistence enables contextual conversations, user personalization, stateful workflows, and progress tracking across multiple user interactions.

Configuration

Configure which conversation variables to update and specify their source data. You can assign multiple variables in a single node.

Variable Assignment Configuration Interface

Variable - Select the conversation variable to write to

Set Variable - Choose the source data from upstream workflow nodes

Operation Mode - Determine how to update the variable (overwrite, append, clear, etc.)

Operation Modes

Different variable types support different operations based on their data structure:

String

• Overwrite - Replace with another string variable

• Clear - Remove the current value

• Set - Manually assign a fixed value

Number

• Overwrite - Replace with another number variable

• Clear - Remove the current value

• Set - Manually assign a fixed value

• Arithmetic - Add, subtract, multiply, or divide the current value by another number

Boolean

• Overwrite - Replace with another boolean variable

• Clear - Remove the current value

• Set - Manually assign a fixed value

Object

• Overwrite - Replace with another object variable

• Clear - Remove the current value

• Set - Manually define the object structure and values

Array

• Overwrite - Replace with another array variable of the same type

• Clear - Remove all elements from the array

• Append - Add a single element to the end of the array

• Extend - Add all elements from another array of the same type

• Remove First/Last - Remove the first or last element from the array

Array operations are particularly powerful for building memory systems, checklists, and conversation histories that grow over time.

Common Implementation Patterns

Smart Memory System

Build chatbots that automatically detect and store important information from conversations:

Smart Memory System Workflow

The system analyzes user input for memorable facts, extracts structured information, and appends it to a persistent memories array for future reference in conversations.

User Preferences Storage

Store user preferences like language settings, notification preferences, or display options:

User Preferences Management

Use Overwrite mode to capture initial preferences from user input, then reference them in all subsequent LLM responses for personalized interactions.

Progressive Checklists

Build guided workflows that track completion status across multiple conversation turns:

Progressive Checklist Implementation

Use array conversation variables to track completed items. The Variable Assigner updates the checklist each turn, while the LLM references it to guide users through remaining tasks.