Can I make my own REST API?

On average, it costs $20,000 to build a relatively simple API. This figure assumes that you’re building a secure, documented, fully-featured API with the services of an experienced API developer based in the United States.

Creating your own RESTful API can be a great way to build a business around data you’ve collected or a service you’ve created , or it can just be a fun personal project that allows you to learn a new skill.16 Nis 2021

How to Design a REST API