Schema Stitching Config Structure

{
  "title": "Schema Stitching Configuration Structure",
  "description": "Document structure for configuring a GraphQL schema stitching gateway.",
  "type": "object",
  "structure": {
    "subschemas": {
      "type": "array",
      "description": "Array of remote or local GraphQL subschemas to stitch together.",
      "items": {
        "schema": "GraphQL schema SDL or executable schema object",
        "url": "Remote service endpoint URL",
        "batch": "Enable DataLoader-style batching",
        "merge": {
          "TypeName": {
            "selectionSet": "Key fields selection set e.g. { id }",
            "fieldName": "Query field to fetch merged type",
            "argsFromKeys": "Map keys to query args function",
            "key": "Extract merge key from object function"
          }
        },
        "transforms": "Array of schema transforms (rename, filter, wrap)"
      }
    },
    "typeDefs": "Additional GraphQL SDL type extensions",
    "resolvers": "Additional resolver implementations",
    "mergeTypes": "Auto-merge same-named types across subschemas"
  },
  "approaches": {
    "schema_extensions": {
      "description": "Traditional delegation method using extend keyword in typeDefs",
      "use_case": "Adding cross-service fields to existing types"
    },
    "programmatic_type_merging": {
      "description": "Code-based configuration of type merging in subschema config",
      "use_case": "Merging distributed entity types by shared key"
    },
    "directive_type_merging": {
      "description": "SDL-based configuration using @key, @merge, @computed directives",
      "use_case": "Self-describing subservices with gateway-reloadable config"
    }
  },
  "key_packages": {
    "@graphql-tools/stitch": "Core schema stitching package",
    "@graphql-tools/schema": "Schema creation utilities",
    "@graphql-tools/utils": "Shared utilities",
    "@graphql-tools/stitching-directives": "Directive-based stitching SDL support",
    "@graphql-tools/wrap": "Schema wrapping and transforms",
    "@graphql-tools/delegate": "Schema delegation helpers",
    "@graphql-tools/batch-execute": "Batched query execution"
  }
}