GraphQL.JS is the reference implementation to The GraphQL Specification, it’s designed to be simple to use and easy to understand while closely following the Specification.

You can build GraphQL servers, clients, and tools with this library, it’s designed so you can choose which parts you use, for example, you can build your own parser and use the execution/validation from the library. There also a lot of useful utilities for schema-diffing, working with arguments, …

In the following chapters you’ll find out more about the three critical pieces of this library

• The GraphQL language
• Document validation
• GraphQL Execution

You can also code along on a tutorial.