Discovering Schema Information

Using Introspection

Query the below field

__schema

Probing for Introspection

If introspection is enabled, the response returns the names of all available queries.

    #Introspection probe request

    {
        "query": "{__schema{queryType{name}}}"
    }

Running a Full Introspection Query

The example query below returns full details on all queries, mutations, subscriptions, types, and fragments.

 #Full introspection query

    query IntrospectionQuery {
        __schema {
            queryType {
                name
            }
            mutationType {
                name
            }
            subscriptionType {
                name
            }
            types {
             ...FullType
            }
            directives {
                name
                description
                args {
                    ...InputValue
            }
            onOperation  #Often needs to be deleted to run query
            onFragment   #Often needs to be deleted to run query
            onField      #Often needs to be deleted to run query
            }
        }
    }

    fragment FullType on __Type {
        kind
        name
        description
        fields(includeDeprecated: true) {
            name
            description
            args {
                ...InputValue
            }
            type {
                ...TypeRef
            }
            isDeprecated
            deprecationReason
        }
        inputFields {
            ...InputValue
        }
        interfaces {
            ...TypeRef
        }
        enumValues(includeDeprecated: true) {
            name
            description
            isDeprecated
            deprecationReason
        }
        possibleTypes {
            ...TypeRef
        }
    }

    fragment InputValue on __InputValue {
        name
        description
        type {
            ...TypeRef
        }
        defaultValue
    }

    fragment TypeRef on __Type {
        kind
        name
        ofType {
            kind
            name
            ofType {
                kind
                name
                ofType {
                    kind
                    name
                }
            }
        }
    }

Note

If introspection is enabled but the above query doesn't run, try removing the onOperation, onFragment, and onField directives from the query structure. Many endpoints do not accept these directives as part of an introspection query, and you can often have more success with introspection by removing them.

Visualizing Introsepection Results

http://nathanrandal.com/graphql-visualizer/

GraphQL Visualizer

This is an online tool that takes the results of an introspection query and produces a visual representation of the returned data, including the relationships between operations and types.

Suggestions

Even if introspection is entirely disabled, you can sometimes use suggestions to glean information on an API's structure.

Suggestions are a feature of the Apollo GraphQL platform in which the server can suggest query amendments in error messages.

These are generally used where a query is slightly incorrect but still recognizable (for example, There is no entry for 'productInfo'. Did you mean 'productInformation' instead?).

You can potentially glean useful information from this, as the response is effectively giving away valid parts of the schema.

GitHub - nikitastupin/clairvoyance: Obtain GraphQL API schema despite disabled introspection!GitHub

Clairvoyance is a tool that uses suggestions to automatically recover all or part of a GraphQL schema, even when introspection is disabled. This makes it significantly less time consuming to piece together information from suggestion responses.

You cannot disable suggestions directly in Apollo. See this GitHub thread for a workaround.