Variables

Learn how to properly leverage variables in your AI Workflows

Variables in MindStudio are dynamic placeholders that store data during workflow execution. They allow you to pass information between blocks and workflows seamlessly.

Example:

  • Variable Name: userName

  • Usage: "Hello, {{userName}}! Welcome to our app."

Creating Variables

Variables are created automatically in MindStudio whenever:

  • A User Input collects data.

  • A block generates an output (e.g., Generate Text Block, Analyze Image Block).

  • You manually define them in the Start Block.

Types of Variables

Launch Variables

These are defined in the Start Block of your workflow. Values for these variables are passed in as arguments when a workflow is run via API or via the Run Workflow block.

Runtime Variables

Some blocks, such as Generate Text Blocks or User Input Blocks, assign values for the variable while the workflow is running. For Example, after performing a Google Search, the block can store the results in a variable called google_result.

Calling Variables

To use a variable in any block or prompt, reference it by enclosing the variable name in double curly braces: {{variable_name}}.

Example Calling Variables in a Generate Text Block:

Summarize the article titled "{{articleTitle}}". 

In the summary, make sure to write about the following topic: 
{{topic}}

Extracting a Value from a JSON Structure

MindStudio provides tools for extracting specific values from JSON objects using the JSON Path syntax and the get helper. This allows workflows to handle and manipulate structured data with precision, making them more dynamic and adaptable.

get Helper - Query JSON Variables

The get helper allows you to query JSON variables for specific values using JSON Path expressions. This feature is especially useful when working with nested or complex JSON structures.

Syntax:

{{get myVariable "$.path.to.value"}}

Example 1: Extract a Nested Value:

Given the following JSON assigned to myJsonVariable:

{
    "user": {
        "name": "Alice",
        "details": {
            "email": "alice@example.com"
        }
    }
}

Use this to extract the email address:

{{get myJsonVariable "$.user.details.email"}}

Output: alice@example.com

Example 2: Extract the First Item in an Array:

Given the following JSON:

{
    "items": [
        {"id": 1, "name": "Foo"},
        {"id": 2, "name": "Bar"}
    ]
}

Use this to extract the name of the first item:

{{get myJsonVariable "$.items[0].name"}}

Output: Foo

Example 3: Extract Multiple Values:

JSON Path also allows for querying multiple elements. Given the following JSON:

{
    "items": [
        {"id": 1, "name": "Foo"},
        {"id": 2, "name": "Bar"}
    ]
}
{{get myJsonVariable "$.items[*].name"}}

Output: ["Foo", "Bar"]

Best Practices When Extracting JSON

  1. Use a JSON Path Tester: Tools like JSONPath Online Evaluator can help you refine and test your JSON Path queries.

  2. Validate JSON Structure: Ensure your variable contains valid JSON data before attempting to extract values.

  3. Handle Missing Values: Include fallback logic in your workflow to handle cases where the expected path does not exist in the JSON.

Using Handlebars Templating

MindStudio leverages the Handlebars templating language to make working with variables intuitive and powerful. Handlebars allows you to include, manipulate, and conditionally render data directly in your prompts, outputs, and logic.

Conditional Logic

Handlebars supports if-else logic for dynamic outputs:

{{#if userName}}
Hello, {{userName}}! How can we assist you today?
{{else}}
Hello! Please log in to get started.
{{/if}}

For a full list of expressions, see Handlebars Documentation.

Special Handlebars Methods in MindStudio

In addition to standard Handlebars features, MindStudio introduces two special methods for advanced functionality:

{{json varName}}

Converts a JSON object into a string format.

Example:

If userProfile contains:

{
    "name": "John",
    "age": 30
}

Usage:

{{json userProfile}}

Output:

{"name":"John","age":30}

{{sample varName number token}}

Extracts a portion of the variable's content based on specified parameters.

  • Parameters:

    • varName: The variable to sample.

    • number: The number of items (e.g., lines, words, or letters). If negative, starts from the end.

    • token: The type of unit to extract (line, word, or letter).

  • Examples:

    • Extract the first 5 words:

      {{sample textVar 5 word}}

    • Extract the last 3 lines:

      {{sample textVar -3 line}}

    • Extract the first 10 letters:

      {{sample textVar 10 letter}}

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