When working with APIs, it's common to create new objects such as a new user, post, or any other data. After creating the object, you may need to return the unique ID associated with the newly created object for further operations. Here's a simple guide on how to return the ID of an object created in an API.

1. Use a consistent naming convention: When designing your API endpoints, make sure to use a consistent naming convention for the response. For example, you can use 'id' or 'objectId' to represent the unique identifier of the object.

2. Include the ID in the response payload: When the object is successfully created, make sure to include the ID in the response payload. This can be achieved by modifying the API endpoint to include the ID in the response body.

3. Use proper HTTP status codes: It's important to use appropriate HTTP status codes to indicate the success or failure of the object creation. When the object is successfully created, use the status code 201 (Created) along with the returned ID in the response.

4. Provide clear documentation: Ensure that the API documentation clearly states the expectations for returning the ID of the created object. This will help developers understand how to retrieve the ID and use it in subsequent API calls.

5. Test the API endpoint: Before deploying the API to production, thoroughly test the API endpoint to ensure that the ID is returned correctly when an object is created. This will help catch any potential issues or bugs early on.

By following these simple steps, you can easily return the ID of an object created in an API. This will allow for seamless integration with other parts of your application and provide a smooth experience for developers using your API. Remember to keep your API consistent and well-documented, as this will make it easier for developers to work with.