> ## Documentation Index > Fetch the complete documentation index at: https://requestly-mintlify-changelog-requestly-past-week-38456.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Using Variables in API Requests Once you've defined variables in Requestly—whether global, environment, collection, or subcollection — you can reference them directly in your API requests. This allows you to dynamically inject values into URLs, headers, request bodies, scripts, and more. ## **Use Variables in API Requests** ### **Step 1: Create or Open a Request** Create or open an existing request in the **API Client**.

### **Step 2: Replace Static Values** Replace static values with your environment variables using the `{{variable_name}}` syntax.

### **Step 3: View Variable Values** Hover over a variable to see its resolved value.

## **Test Your Setup** ### **Step 1: Execute the Request** Click **Send** to execute the request. ### **Step 2: Verify Resolved Values** Check the resolved values in the **Request Preview** to ensure that variables are substituted correctly.

If a variable isn't resolving, verify that the variable name matches exactly (case-sensitive) and is present in the selected environment.