Grafana UI MCP Server

/** * Request handler setup for the Model Context Protocol (MCP) server. * * This file configures how the server responds to various MCP requests by setting up * handlers for resources, resource templates, tools, and prompts. */ import { CallToolRequestSchema, ListResourcesRequestSchema, ListResourceTemplatesRequestSchema, ReadResourceRequestSchema, ListToolsRequestSchema, GetPromptRequestSchema, ListPromptsRequestSchema, ErrorCode, McpError, } from "@modelcontextprotocol/sdk/types.js"; import { type Server } from "@modelcontextprotocol/sdk/server/index.js"; import { resourceHandlers, resources } from "./resources.js"; import { promptHandlers, prompts } from "./prompts.js"; import { toolHandlers, tools, unifiedToolSchema } from "./tools.js"; import { getResourceTemplate, resourceTemplates, } from "./resource-templates.js"; import { z } from "zod"; /** * Sets up all request handlers for the MCP server * @param server - The MCP server instance */ export const setupHandlers = (server: Server): void => { // List available resources when clients request them server.setRequestHandler(ListResourcesRequestSchema, () => ({ resources })); // Resource Templates server.setRequestHandler(ListResourceTemplatesRequestSchema, () => ({ resourceTemplates, })); // List available tools server.setRequestHandler(ListToolsRequestSchema, async () => ({ tools: Object.values(tools), })); // Return resource content when clients request it server.setRequestHandler(ReadResourceRequestSchema, async (request) => { const { uri } = request.params ?? {}; try { // Check if this is a static resource const resourceHandler = resourceHandlers[uri as keyof typeof resourceHandlers]; if (resourceHandler) { const result = await Promise.resolve(resourceHandler()); // Ensure we're returning the expected structure with contents array // Format as text content with a resource-like uri return { contentType: result.contentType, contents: [ { uri: uri, // Use the requested URI text: result.content, // Use text field for plain content }, ], }; } // Check if this is a generated resource from a template const resourceTemplateHandler = getResourceTemplate(uri); if (resourceTemplateHandler) { const result = await Promise.resolve(resourceTemplateHandler()); // Ensure we're returning the expected structure with contents array return { contentType: result.contentType, contents: [ { uri: uri, // Use the requested URI text: result.content, // Use text field for plain content }, ], }; } throw new McpError(ErrorCode.InvalidParams, `Resource not found: ${uri}`); } catch (error) { if (error instanceof McpError) throw error; throw new McpError( ErrorCode.InternalError, `Error processing resource: ${error instanceof Error ? error.message : String(error)}`, ); } }); // List available prompts server.setRequestHandler(ListPromptsRequestSchema, () => ({ prompts: Object.values(prompts), })); // Get specific prompt content with optional arguments server.setRequestHandler(GetPromptRequestSchema, (request) => { const { name, arguments: args } = request.params; const promptHandler = promptHandlers[name as keyof typeof promptHandlers]; if (promptHandler) return promptHandler(args as any); throw new McpError(ErrorCode.InvalidParams, `Prompt not found: ${name}`); }); // Tool request Handler - executes the requested tool with provided parameters server.setRequestHandler(CallToolRequestSchema, async (request) => { const { name, arguments: params } = request.params ?? {}; if (!name || typeof name !== "string") { throw new McpError(ErrorCode.InvalidParams, "Tool name is required"); } const handler = toolHandlers[name as keyof typeof toolHandlers]; if (!handler) { throw new McpError(ErrorCode.InvalidParams, `Tool not found: ${name}`); } try { // Validate tool input with Zod if applicable const toolSchema = getToolSchema(name); let validatedParams = params || {}; // Ensure params is never undefined if (toolSchema) { try { validatedParams = toolSchema.parse(validatedParams); } catch (validationError) { if (validationError instanceof z.ZodError) { const errorMessages = validationError.errors .map((err) => `${err.path.join(".")}: ${err.message}`) .join(", "); throw new McpError( ErrorCode.InvalidParams, `Invalid parameters: ${errorMessages}`, ); } throw validationError; } } // Ensure handler returns a Promise const result = await Promise.resolve(handler(validatedParams as any)); return result; } catch (error) { if (error instanceof McpError) throw error; throw new McpError( ErrorCode.InternalError, `Error executing tool: ${error instanceof Error ? error.message : String(error)}`, ); } }); // Add global error handler server.onerror = (error) => { console.error("[MCP Server Error]", error); }; }; /** * Get Zod schema for tool validation if available * @param toolName Name of the tool * @returns Zod schema or undefined */ function getToolSchema(toolName: string): z.ZodType | undefined { try { switch (toolName) { case "grafana_ui": return unifiedToolSchema; default: return undefined; } } catch (error) { console.error("Error getting schema:", error); return undefined; } }