Variables

Variables allow you to create dynamic, personalized USSD experiences.

Basics

Variables store data during a session and can be used in node content.

Syntax

Use ${variableName} to reference a variable:

Welcome, ${name}!
Your balance is ${balance} GHS.

Creating Variables

Variables are created when:

1. User input - Input nodes store responses in a variable you name
2. Action results - API responses saved to variables
3. Set variable - Explicitly set using an Action node

Variable Types

User Input Variables

When you add an Input node, you specify a variable name. The user's response is stored there.

Example:

• Input prompt: "Enter your name:"
• Variable name: name
• User enters: "John"
• Result: ${name} = "John"

System Variables

Available automatically in every session:

Computed Variables

Use an Action node with "Set Variable" to compute values:

Expressions

Use expressions for dynamic values and conditions.

Arithmetic

String Operations

Comparison

Logical

Using Variables in Nodes

In Menu Titles

Welcome ${name}! Balance: ${balance} GHS

User sees:

Welcome John! Balance: 500 GHS
1. Send Money
2. Check Balance

In Display Messages

Transfer Summary:
Amount: ${amount} GHS
Fee: ${fee} GHS
Total: ${total} GHS
To: ${recipientName}

In Branch Conditions

In API URLs

https://api.example.com/users/${phone}

Working with API Responses

When an Action node makes an HTTP request, the response is stored in a variable.

Accessing Response Data

If your API returns:

{
  "user": {
    "name": "John",
    "balance": 500
  },
  "status": "success"
}

Access nested properties with dot notation:

Array Access

For arrays, use index notation:

Default Values

Provide fallback values for undefined variables:

Formatting

Numbers

Dates

Phone Numbers

Best Practices

Naming Conventions

Use clear, descriptive names:

Validation

Always validate user input. In Input nodes, set validation rules:

Error Handling

Use Branch nodes to check for undefined variables before using them:

Next Steps