Hasura is an open source engine that connects to your databases & microservices and auto-generates a production-ready GraphQL backend.
Daptin is a headless CMS server which servers data from MySQL/PostgreSQL/SQLite over JSONAPI.org or GraphQL. With Daptin you can design your data model and have a production ready APIs reliably backed by persistent database online with in hours.
PostgREST is a standalone web server that turns your PostgreSQL database directly into a RESTful API. The structural constraints and permissions in the database determine the API endpoints and operations.