The difference between using an API and using a bought third-party package is that you can usually continue using the package if the third party discontinues it

The difference between using an API and using a bought third-party package is that you can usually continue using the package if the third party discontinues it or goes out of business. You can also usually choose when to upgrade if your app needs to be modified to handle the upgrade. With an API you're at the third-party's mercy: you can wake up one day to discover that you are out of business because the API changed or went away. If your business has a dependency like this, you'd better be prepared to close sbop without notice or have an insurance policy. The latter could either be many other sources of revenue with different dependencies, an actual insurance policy that will let you take care of your employees and customers and shut down gracefully, or some contract with the API provider that will force them to pay you to do the same.