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Develop with GraphQL

GraphQL is a query language for APIs. A REST API has a separate endpoint for each resource, so you often make several calls to collect related data. A GraphQL API has one endpoint, and you request exactly the fields you need in a single query.

Your GraphQL endpoint is https://tenant-name.is.here.io/here/api/graphql

For example, a REST API might need three calls:

GET /users/123
GET /users/123/posts
GET /posts/456/comments

A GraphQL API needs one query:

query {
    user(id: "123") {
        name
        email
        posts {
            title
            comments {
                text
                author
            }
        }
    }
}
info

This example is generic. It doesn't reflect HERE APIs.

Schema​

The schema defines the queries, mutations, and types that an API supports. Use introspection to read the HERE schema.

Introspection​

Introspection queries ask the API to describe itself: its types, fields, queries, and mutations. Introspection fields begin with two underscores:

  • __schema returns the whole schema.
  • __type(name: String!) returns one type.
  • __typename returns the name of the current object's type.

List every type:

query {
    __schema {
        types {
            name
            kind
            description
        }
    }
}

List the fields of one type:

query {
    __type(name: "User") {
        name
        kind
        fields {
            name
            type {
                name
                kind
            }
            description
        }
    }
}

List every query and its arguments:

query {
    __schema {
        queryType {
            name
            fields {
                name
                args {
                    name
                    type {
                        name
                    }
                }
            }
        }
        mutationType {
            name
        }
        subscriptionType {
            name
        }
    }
}

HERE GraphQL APIs​

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