Here’s an improved version of your guide with clearer explanations and a stronger emphasis on why each prerequisite matters:

Prerequisites

ReAPI’s design interface is fully browser-based and optimized for Chrome. However, certain browser limitations can affect API testing. To ensure smooth testing and full feature access, review the following prerequisites before getting started.

Install ReAPI’s Chrome Extension

• Bypass CORS Restrictions: Chrome enforces strict CORS (Cross-Origin Resource Sharing) policies, which can prevent API calls to servers with restrictive CORS configurations. Installing the ReAPI Chrome extension removes these restrictions, allowing API calls to function as intended.
• Full Header & Cookie Access: Some APIs require access to cookies or full response headers, but Chrome limits this information for cross-origin requests. The extension ensures that all headers and authentication details remain accessible, enabling comprehensive testing.

Without this extension, API calls to certain servers may fail, and response headers may be incomplete, limiting debugging and validation.

Understand JSONata for Expressions

• Why JSONata? ReAPI integrates JSONata as its core expression language for extracting, transforming, and validating API responses.
• When You Need It:
  • For simple extractions: response.data.userId
  • For transformations: Converting response structures, filtering arrays, or performing calculations
  • For assertions: Validating API responses dynamically

While ReAPI provides a no-code experience, understanding JSONata will help unlock advanced testing capabilities. Check the [JSONata guide] for more details.

Browser Limitations in Load Testing

• Performance Constraints: Browsers, including Chrome, are not optimized for high-volume API testing. Running thousands of concurrent requests in the browser can significantly slow down execution.
• Solution: Use the ReAPI CLI (@reapli/cli) to run tests in a background service, ensuring stable and scalable performance for load testing.

For serious load testing, switching to CLI execution is highly recommended. Refer to the [CLI guide] for setup instructions.

By ensuring these prerequisites are in place, you’ll have a smoother and more effective experience across all ReAPI modules.