A developer is building an application that will use an Amazon API Gateway API with...

To give the frontend team immediate access to stable endpoints without waiting for a real backend implementation, the simplest approach is to use API Gateway MOCK integration. A MOCK integration lets API Gateway generate a response directly, without invoking Lambda or any other backend. This is ideal for early UI development because you can return consistent, predefined payloads and status codes for each method.

With MOCK integration, you configure an integration request (often using a static mapping template) to produce a dummy request payload that triggers a response, and then you configure integration responses to return specific HTTP status codes (such as 200, 400, 500) along with predefined JSON bodies. You can also set response headers (for example, Content-Type: application/json) and use mapping templates to shape the returned JSON. This satisfies the requirement to “return predefined HTTP status codes and JSON responses” while minimizing development effort and avoiding the need to deploy placeholder Lambda functions.

Option A (AWS_PROXY with Lambda) can work, but it requires creating and deploying Lambda functions and IAM permissions just to return static data—more effort than necessary. Option C (HTTP PROXY) depends on an external placeholder service, which adds another system to build and maintain. Option D is incorrect because HTTP status codes are not defined in the method request; they are defined through method responses and realized through integration responses in API Gateway’s integration configuration.

Therefore, B is the best solution: MOCK integration with integration request/response mappings provides quick, code-free stubs that unblock frontend development.