Directus CMS

Any kind of SQL database may be converted into an API with the help of the Directus Open Data Platform, which is part of the headless CMS.

Using its REST API or GraphQL, Directus, a NodeJS Headless CMS, connects your website or apps to a SQL database.

It is made up of a web app for managing content and an API that enables developers to link that data to a variety of clients, including websites, native applications, kiosks, IoT devices, and other projects that are data-driven.

Storyblok

Storyblok is also a web service, so you only need to register an account to create a project. It is more difficult to use than Contentful, but has more room for customization. In addition to the main entities, here it's possible to make auxiliary ones to use as components of the main entities. Storyblok allows grouping entities and content independently.

Also, this CMS has a unique feature. It can include your code on the frontend to see a preview of the content being created, which is important for content managers.

Of course, Storyblok has some flaws. It's not beginner-friendly, so a bit of learning is required to understand its interface. Then, it is only available in the paid version. Storyblok also has restrictions for entities, content, and files, but they are much wider than in Contentful.

Finally, Storyblok is a good CMS if you have fairly complex data structures in your project and want to fine-tune them.