What is a purpose of the nodeField?

[SVilgelm]

Hello, I was a bit surprised to see "Node" in the schema. After some research I found this code

gateway/gateway.go

Lines 281 to 294 in 98c7fbe

	var nodeField = &QueryField{
	Name: "node",
	Type: ast.NamedType("Node", &ast.Position{}),
	Arguments: ast.ArgumentDefinitionList{
	&ast.ArgumentDefinition{
	Name: "id",
	Type: ast.NonNullNamedType("ID", &ast.Position{}),
	},
	},
	Resolver: func(ctx context.Context, args map[string]interface{}) (string, error) {
	// pass it to the user
	return args["id"].(string), nil
	},
	}

I see that the nodeField is added to the schema by default here:

gateway/gateway.go

Line 136 in 98c7fbe

queryFields: []*QueryField{nodeField},

My question is - what is it? Why do we have by default and is there a way to remove?

[AlecAivazis]

Hey @SVilgelm!

The node field and corresponding interface is used by the gateway to correlate entities in various backing services. Because of that, it can't really be removed from the gateway without replacing it with some other method of uniquely identifying an entity of a given type.

You can read more about the Node interface and the gateway's approach to schema federation here: https://itnext.io/a-guide-to-graphql-schema-federation-part-1-995b639ac035