refactor!: remove per query endpoints and headers (#17)

This opens up the MCP server to lots of security issues by leaking headers and allowing endpoints and headers to be poisoned.

If you need this specific use case of allowing different endpoints and headers per query/introspection then please fork the latest v1.

Thanks @mweidner037 for notifying on this issue.

BREAKING RELEASE: Endpoints and headers input options removed due to inherent security vulnerabilities

Author: blurrah

src/index.ts

@@ -5,7 +5,6 @@ import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js"
 import { parse } from "graphql/language";
 import { z } from "zod";
 import { checkDeprecatedArguments } from "./helpers/deprecation.js";
-import { parseAndMergeHeaders } from "./helpers/headers.js";
 import {
 	introspectEndpoint,
 	introspectLocalSchema,
@@ -18,7 +17,10 @@ checkDeprecatedArguments();
 const EnvSchema = z.object({
 	NAME: z.string().default("mcp-graphql"),
 	ENDPOINT: z.string().url().default("http://localhost:4000/graphql"),
-	ALLOW_MUTATIONS: z.enum(['true', 'false']).transform((value) => value === 'true').default("false"),
+	ALLOW_MUTATIONS: z
+		.enum(["true", "false"])
+		.transform((value) => value === "true")
+		.default("false"),
 	HEADERS: z
 		.string()
 		.default("{}")
@@ -65,30 +67,14 @@ server.resource("graphql-schema", new URL(env.ENDPOINT).href, async (uri) => {
 server.tool(
 	"introspect-schema",
 	"Introspect the GraphQL schema, use this tool before doing a query to get the schema information if you do not have it available as a resource already.",
-	{
-		endpoint: z
-			.string()
-			.url()
-			.optional()
-			.describe(
-				`Optional: Override the default endpoint, the already used endpoint is: ${env.ENDPOINT}`,
-			),
-		headers: z
-			.union([z.record(z.string()), z.string()])
-			.optional()
-			.describe(
-				`Optional: Add additional headers, the already used headers are: ${JSON.stringify(env.HEADERS)}`,
-			),
-	},
-	async ({ endpoint, headers }) => {
+	{},
+	async () => {
 		try {
 			let schema: string;
 			if (env.SCHEMA) {
 				schema = await introspectLocalSchema(env.SCHEMA);
 			} else {
-				const useEndpoint = endpoint || env.ENDPOINT;
-				const useHeaders = parseAndMergeHeaders(env.HEADERS, headers);
-				schema = await introspectEndpoint(useEndpoint, useHeaders);
+				schema = await introspectEndpoint(env.ENDPOINT, env.HEADERS);
 			}
 
 			return {
@@ -111,21 +97,8 @@ server.tool(
 	{
 		query: z.string(),
 		variables: z.string().optional(),
-		endpoint: z
-			.string()
-			.url()
-			.optional()
-			.describe(
-				`Optional: Override the default endpoint, the already used endpoint is: ${env.ENDPOINT}`,
-			),
-		headers: z
-			.union([z.record(z.string()), z.string()])
-			.optional()
-			.describe(
-				`Optional: Add additional headers, the already used headers are: ${JSON.stringify(env.HEADERS)}`,
-			),
 	},
-	async ({ query, variables, endpoint, headers }) => {
+	async ({ query, variables }) => {
 		try {
 			const parsedQuery = parse(query);
 
@@ -159,14 +132,11 @@ server.tool(
 		}
 
 		try {
-			const useEndpoint = endpoint || env.ENDPOINT;
-			const useHeaders = parseAndMergeHeaders(env.HEADERS, headers);
-
-			const response = await fetch(useEndpoint, {
+			const response = await fetch(env.ENDPOINT, {
 				method: "POST",
 				headers: {
 					"Content-Type": "application/json",
-					...useHeaders,
+					...env.HEADERS,
 				},
 				body: JSON.stringify({
 					query,