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Variables are the backbone of dynamic prompting in Adaline. They let you build a single prompt template that adapts to countless scenarios — replacing static content with placeholders that can be swapped at runtime. Instead of maintaining separate prompts for different customers, use cases, or contexts, you create one powerful template with variables.

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How variables work

When you type {{variable_name}} anywhere in a prompt message, Adaline automatically detects it and creates a corresponding entry in the Variable Editor panel. You can then set values for each variable before running the prompt in the Playground. Defining variables in the Adaline Editor

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Variable name constraints

Variable names must follow specific rules to ensure compatibility across the platform: Allowed characters:
  • Letters: a-z and A-Z
  • Numbers: 0-9
  • Underscores: _
  • Hyphens: -
ValidInvalid
{{user_question}}{{user question}} (spaces)
{{product_name}}{{user.question}} (period)
{{user-id}}{{user@name}} (special characters)
{{item_123}}{{user/name}} (slash)

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Variable types

Adaline supports three types of variables, each suited to a different content modality:

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Text variables

The most common variable type. Define them directly in your prompt text using the {{variable_name}} syntax. Without variables: 
Write a haiku about nature that captures a peaceful moment.
With variables: 
Write a haiku about {{topic}} that evokes {{emotion}} and includes {{element}}
Set values for text variables in the Variable Editor: Setting variable values in the Variable Editor

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Image variables

Image variables let you dynamically swap visual inputs without changing the prompt structure. To create one:
  1. Click the image button in a message block.
  2. Select From Variable and give it a descriptive name.
  3. In the Variable Editor, attach the actual image (URL, base64, or file upload).
See Use Images in Prompts for detailed setup steps.

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PDF variables

PDF variables work the same way as image variables but for document inputs. To create one:
  1. Click the PDF button in a message block.
  2. Select From Variable and give it a descriptive name.
  3. In the Variable Editor, attach the actual PDF (URL, base64, or file upload).
See Use PDFs in Prompts for detailed setup steps.

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Variable sources

Variables can be powered by different sources depending on your workflow needs: Choosing a variable source
SourceDescriptionUse case
StaticDirect text, image, or PDF content set manually in the Variable Editor.Simple testing with fixed inputs.
APIFetches live data from external HTTP endpoints at runtime.Injecting real-time data like user profiles, product catalogs, or live metrics.
PromptExecutes another prompt and uses its output as the variable value.Building agent-like workflows with prompt chaining.
To change a variable’s source:
1

Create a variable

Add a {{variable_name}} placeholder in your prompt text, or create an image/PDF variable through the respective buttons.
2

Select the source type

In the Variable Editor, click on the variable and select the desired source type: static value, API, or Prompt.Selecting a variable source
For detailed configuration of dynamic sources, see:

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Dynamic sources in datasets

When your variable uses an API or Prompt source and you have a linked dataset, the dynamic source is executed for each row individually. This means:
  • API variables make a unique HTTP request per row, with placeholders like {{userId}} resolved from that row’s data.
  • Prompt variables execute the referenced prompt once per row, passing the row’s context.
  • Results are stored in the dataset cells and can be used for subsequent evaluations.
Dynamic variable sources in Adaline

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Best practices

  • Use descriptive names — Choose names like {{user_purchase_history}} instead of {{var1}} so that team members can understand the prompt at a glance.
  • Keep variables focused — Each variable should represent one piece of data. Avoid packing multiple values into a single variable.
  • Test with linked datasets — Connect a dataset to your variables to efficiently test across many different input combinations.

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Next steps

Use APIs in Prompts

Fetch live data from external endpoints at runtime.

Use Other Prompts in Prompts

Chain prompts together for complex workflows.