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Variables make your prompts dynamic and reusable by allowing you to substitute values at runtime. This is perfect for prompts that need customization for different contexts.

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Variable Syntax

PromptRepo uses a double-curly-brace syntax for variables: 
{{variableName}}
Variable names are case-sensitive. {{userName}} and {{username}} are treated as different variables.

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Creating Prompts with Variables

1

Add Variables to Content

When creating or editing a prompt, include variables using the {{variableName}} syntax:
You are a helpful assistant specializing in {{topic}}.
Please help {{userName}} with their question about {{subject}}.
In this example, there are three variables:
  • topic
  • userName
  • subject
2

Save Your Prompt

Save the prompt normally. PromptRepo automatically detects all variables in the content.
3

Access the Resolve Tab

When you view a prompt with variables, a Resolve tab appears automatically in the prompt detail view.

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Resolving Variables

The Resolve tab provides a form to fill in variable values and preview the final output.
1

Open the Resolve Tab

Click the Resolve tab in your prompt detail view.
The Resolve tab only appears if your prompt contains at least one variable.
2

Fill in Variable Values

The system displays an input field for each detected variable. Enter the values you want to substitute:
  • topic: Python programming
  • userName: Alex
  • subject: list comprehensions
3

Preview Resolved Content

As you type, the resolved content updates in real-time below the form, showing:
You are a helpful assistant specializing in Python programming.
Please help Alex with their question about list comprehensions.
4

Copy Resolved Prompt

Click the Copy button to copy the resolved prompt to your clipboard, ready to use in your application or AI tool.

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Saving Variable Snapshots

Snapshots let you save specific variable combinations for reuse.
1

Fill in Variables

In the Resolve tab, enter values for all variables you want to save.
2

Save Snapshot

Click the Save Snapshot button (if available) to store this combination.Snapshots preserve:
  • All variable values
  • The prompt version they were created with
  • A timestamp
3

View Saved Snapshots

Switch to the Snapshots tab to see all saved variable combinations for this prompt.
4

Load a Snapshot

Click on any snapshot to automatically load its values into the Resolve tab.
Use snapshots to save commonly-used variable combinations, like different user personas or test scenarios.

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Variable Naming Best Practices

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Use Descriptive Names

Good: 
{{userRole}}
{{targetAudience}}
{{outputFormat}}
Poor: 
{{x}}
{{temp}}
{{thing}}

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Use Consistent Naming Conventions

Choose a convention and stick to it:
  • camelCase: {{userName}}, {{maxTokens}}
  • snake_case: {{user_name}}, {{max_tokens}}
  • kebab-case: {{user-name}}, {{max-tokens}}
Spaces inside variable names are supported: {{user name}} is valid, but not recommended for clarity.

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Advanced Variable Usage

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Optional Variables

If a variable is not provided when resolving, the original {{variableName}} placeholder remains in the output: 
Input: "Hello {{name}}, welcome to {{location}}!"
Provided: name = "Sam"
Output: "Hello Sam, welcome to {{location}}!"
This behavior allows you to partially resolve prompts and fill in remaining variables later.

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Variables in Context

Variables can appear multiple times in a single prompt: 
Task: Analyze {{topic}}

Please provide:
1. An overview of {{topic}}
2. Common challenges in {{topic}}
3. Best practices for {{topic}}
All instances of {{topic}} will be replaced with the same value.

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Multiline Variables

Variable values can span multiple lines: 
Prompt content:
{{instructions}}

Variable value:
- Step 1: Do this
- Step 2: Do that
- Step 3: Finish

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Using Variables via API

If you’re accessing prompts via the MCP (Model Context Protocol) API: 
curl -X POST https://your-app-url/api/mcp \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "method": "tools/call",
    "params": {
      "name": "resolve_prompt",
      "arguments": {
        "promptId": "abc-123",
        "variables": {
          "topic": "Python",
          "userName": "Alex"
        }
      }
    }
  }'

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Common Variable Use Cases

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User Personalization

Hello {{userName}}, welcome back!
Your role: {{userRole}}

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Template Parameters

Generate a {{contentType}} about {{topic}}
in {{tone}} tone for {{audience}}.

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Dynamic Instructions

Analyze the following {{fileType}} file:
{{fileContent}}

Focus on: {{analysisAspects}}

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Configuration

Model: {{modelName}}
Max tokens: {{maxTokens}}
Temperature: {{temperature}}

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Troubleshooting

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Variables Not Detected

Ensure you’re using the correct syntax with double curly braces:
  • Correct: {{variable}}
  • Incorrect: {variable}, ${variable}, [[variable]]

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Nested Braces

Nested braces are not supported: 
❌ {{ {{nested}} }}
✓ {{outerVariable}}

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Special Characters

Variable names support most characters but avoid using:
  • Closing braces: }}
  • Only whitespace
If you need literal double curly braces in your content, this is currently not supported. Variables will always be parsed.

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