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Using Variables

Variables make your requests dynamic, reusable, and environment-independent. This guide covers everything you need to know about using variables in Nidra.

What are Variables?​

Variables are placeholders that get replaced with actual values when a request is sent. They allow you to:

  • Reuse the same request across different environments
  • Avoid hardcoding sensitive values
  • Make requests dynamic based on previous responses
  • Share common values across multiple requests

Variable Syntax​

Reference variables using double curly braces:

{{variableName}}

Examples​

In URLs:

{{baseUrl}}/users/{{userId}}

In Headers:

Authorization: Bearer {{accessToken}}

In Request Bodies:

{
  "email": "{{userEmail}}",
  "environment": "{{env}}"
}

In Query Parameters:

?api_key={{apiKey}}&page={{currentPage}}

Variable Scopes​

Variables exist at different scopes with different precedence levels:

1. Global Variables​

Available everywhere in Nidra.

Use for: App-wide settings, defaults

2. Environment Variables​

Specific to the selected environment.

Use for: Server URLs, environment-specific credentials

3. Collection Variables​

Scoped to a specific collection.

Use for: Collection-wide settings, base paths

4. Conduit Variables​

Temporary variables during conduit execution.

Use for: Extracted response data, intermediate values

5. Request Variables​

Local to a single request (rare).

Use for: Request-specific overrides

Precedence​

When the same variable name exists at multiple scopes:

Request > Conduit > Collection > Environment > Global

The most specific scope wins.

Setting Variables​

In Environments​

  1. Go to Environments
  2. Select or create an environment
  3. Add key-value pairs
  4. Save the environment

In Collections​

  1. Open collection settings
  2. Go to the Variables tab
  3. Add variables
  4. Save

During Conduit Execution​

Variables can be set dynamically:

  • Extracted from responses
  • Calculated in script steps
  • Set explicitly in variable steps

Learn about variable extraction →

Common Variable Patterns​

Base URL​

Most common variable:

baseUrl: https://api.example.com/v1

Used in requests:

{{baseUrl}}/users
{{baseUrl}}/posts

Authentication​

Store credentials as variables:

apiKey: your-api-key-here
bearerToken: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...
username: admin
password: ******** (marked as secret)

Dynamic IDs​

Store resource IDs for reuse:

userId: 12345
orderId: 67890
productId: abc-123

Configuration​

Environment-specific settings:

timeout: 5000
retryCount: 3
debug: true

Dynamic Variables​

Nidra provides built-in dynamic variables:

  • {{$timestamp}}: Current Unix timestamp
  • {{$randomInt}}: Random integer
  • {{$randomUUID}}: Random UUID
  • {{$randomEmail}}: Random email address

Example:

{
  "id": "{{$randomUUID}}",
  "timestamp": "{{$timestamp}}",
  "email": "user-{{$randomInt}}@example.com"
}

Variable References in Assertions​

Use variables in assertions to validate dynamic values:

Response field "userId" equals {{expectedUserId}}

Debugging Variables​

View Active Variables​

See all active variables for the current context:

  1. Open the Variables panel
  2. Select the active environment
  3. View resolved values

Variable Console​

The variable console shows:

  • Which variables are set
  • Their current values
  • Which scope they come from
  • Any unresolved variables (showing as {{varName}})

Common Issues​

Unresolved Variables

If a variable shows as {{varName}} in the response:

  • Check the variable name spelling
  • Verify the variable exists in the active scope
  • Ensure the environment is selected
  • Check variable precedence

Best Practices​

  • Use descriptive names: baseUrl not url, userEmail not e
  • Follow naming conventions: camelCase or snake_case consistently
  • Mark secrets appropriately: Hide sensitive values
  • Don't duplicate: Use parent environments for shared variables
  • Document your variables: Add descriptions in environments
  • Keep it DRY: Don't repeat values, use variables instead

Advanced Patterns​

Chained Variables​

Variables can reference other variables:

domain: example.com
apiUrl: https://api.{{domain}}
authUrl: https://auth.{{domain}}

Conditional Variables​

Different values based on environment:

Development:
  baseUrl: http://localhost:3000
  debug: true

Production:
  baseUrl: https://api.example.com
  debug: false

Computed Values​

Use conduit steps to compute values:

Extract "userId" from response
Set "userProfileUrl" to "{{baseUrl}}/users/{{userId}}/profile"

Real-World Example​

Environment: Production

baseUrl: https://api.example.com/v2
apiKey: prod_1234567890
tenantId: acme-corp
timeout: 10000

Request: Get User

GET {{baseUrl}}/tenants/{{tenantId}}/users/{{userId}}

Headers:
  X-API-Key: {{apiKey}}
  Accept: application/json

The request resolves to:

GET https://api.example.com/v2/tenants/acme-corp/users/42

Headers:
  X-API-Key: prod_1234567890
  Accept: application/json

Next Steps​