Is GlideRecord_Mutation documented?

Hi ServiceNow Team!

Is there any documentation about the GlideRecord API with GraphQL?

It is available under this path: /api/now/graphql

We are able to query data with GlideRecord_Query (a sort of SELECT).

However, we are unable to figure out the syntax for mutations (INSERT, UPDATE, DELETE).

Might you provide a link to the documentation or a simple example of them?

Thanks in advance,

Pablo