federation

type EntityFetchSpec struct {
	Subgraph       *Subgraph
	TypeName       string   // entity type, e.g. "User"
	KeyFields      []string // key field names, e.g. ["id"]
	RequiresFields []string // @requires fields to embed in representations beyond key fields
	Selection      string   // the fields to fetch: "reviews {\n  title\n}\n"
	ParentPath     []string // JSON path to the parent in the merged data, e.g. ["user"]
	IsParentList   bool     // true when ParentPath resolves to a list
}

type FetchSpec struct {
	Subgraph  *Subgraph
	Query     string
	Variables []string // variable names from the original operation used here
}

type FieldProjection struct {
	Key      string             // response key (alias or field name)
	Children []*FieldProjection // nil for scalar fields
}

type GraphQLError struct {
	Message    string           `json:"message"`
	Locations  []map[string]int `json:"locations,omitempty"`
	Path       []any            `json:"path,omitempty"`
	Extensions map[string]any   `json:"extensions,omitempty"`
}

type GraphQLRequest struct {
	Query         string         `json:"query"`
	OperationName string         `json:"operationName,omitempty"`
	Variables     map[string]any `json:"variables,omitempty"`
}

type GraphQLResponse struct {
	Data   json.RawMessage `json:"data"`
	Errors []GraphQLError  `json:"errors,omitempty"`
}

type Plan struct {
	// Fetches are the initial per-subgraph queries, safe to run in parallel.
	Fetches []*FetchSpec
	// EntityFetches run after Fetches in order; later steps may depend on earlier ones.
	EntityFetches []*EntityFetchSpec
	// Projection holds the user-requested field tree, used to strip planner-added
	// fields (key fields, __typename, @requires pre-fetch fields) from the final response.
	Projection []*FieldProjection
}

type Subgraph struct {
	EnumName string // join__Graph enum value, e.g. "ACCOUNTS"
	Name     string // human name from @join__graph, e.g. "accounts"
	URL      string // service URL
}

type Supergraph struct {
	// contains filtered or unexported fields
}