mcp-graphql-enhanced

import { buildClientSchema, getIntrospectionQuery, GraphQLObjectType, GraphQLInterfaceType, GraphQLUnionType, GraphQLEnumType, GraphQLScalarType, GraphQLInputObjectType, GraphQLNamedType, printSchema, } from "graphql"; import { readFile } from "node:fs/promises"; /** * Introspect a GraphQL endpoint and return the schema as the GraphQL SDL * @param endpoint - The endpoint to introspect * @param headers - Optional headers to include in the request * @returns The schema */ export async function introspectEndpoint( endpoint: string, headers?: Record<string, string>, ) { const response = await fetch(endpoint, { method: "POST", headers: { "Content-Type": "application/json", ...headers, }, body: JSON.stringify({ query: getIntrospectionQuery(), }), }); if (!response.ok) { throw new Error(`GraphQL request failed: ${response.statusText}`); } const responseJson = await response.json(); // Transform to a schema object const schema = buildClientSchema((responseJson as any).data); // Print the schema SDL return printSchema(schema); } /** * Introspect a GraphQL schema file hosted at a URL and return the schema as the GraphQL SDL * @param url - The URL to the schema file * @returns The schema */ export async function introspectSchemaFromUrl(url: string) { const response = await fetch(url); if (!response.ok) { throw new Error(`Failed to fetch schema from URL: ${response.statusText}`); } const schema = await response.text(); return schema; } /** * Introspect a local GraphQL schema file and return the schema as the GraphQL SDL * @param path - The path to the local schema file * @returns The schema */ export async function introspectLocalSchema(path: string) { const schema = await readFile(path, "utf8"); return schema; } function isObjectLikeType(type: GraphQLNamedType): type is GraphQLObjectType | GraphQLInterfaceType { return 'getFields' in type; } function isUnionType(type: GraphQLNamedType): type is GraphQLUnionType { return 'getTypes' in type; } function isEnumType(type: GraphQLNamedType): type is GraphQLEnumType { return 'getValues' in type; } function isInputObjectType(type: GraphQLNamedType): type is GraphQLInputObjectType { return 'getFields' in type; } export async function introspectTypes( endpoint: string, headers: Record<string, string> = {}, typeNames: string[] ) { const response = await fetch(endpoint, { method: "POST", headers: { "Content-Type": "application/json", ...headers }, body: JSON.stringify({ query: getIntrospectionQuery() }), }); const data = await response.json(); const schema = buildClientSchema(data.data); const result: Record<string, any> = {}; for (const name of typeNames) { const type = schema.getType(name); if (!type) continue; // Handle object/interface types if (isObjectLikeType(type)) { result[name] = { kind: type instanceof GraphQLObjectType ? "OBJECT" : "INTERFACE", description: type.description, fields: Object.fromEntries( Object.entries(type.getFields()).map(([fieldName, field]) => [ fieldName, { type: field.type.toString(), description: field.description, args: field.args.map(arg => ({ name: arg.name, type: arg.type.toString(), description: arg.description, })) } ]) ) }; } // Handle union types else if (isUnionType(type)) { result[name] = { kind: "UNION", description: type.description, possibleTypes: type.getTypes().map(t => t.name) }; } // Handle enums else if (isEnumType(type)) { result[name] = { kind: "ENUM", description: type.description, values: type.getValues().map(v => ({ name: v.name, description: v.description })) }; } // Handle scalars and input objects else if (isInputObjectType(type)) { result[name] = { kind: "INPUT_OBJECT", description: type.description, fields: Object.fromEntries( Object.entries(type.getFields()).map(([fieldName, field]) => [ fieldName, { type: field.type.toString(), description: field.description } ]) ) }; } else if (type instanceof GraphQLScalarType) { result[name] = { kind: "SCALAR", description: type.description }; } } return JSON.stringify(result, null, 2); }