MCP Server Template

Instructions

Implementation Reference

• src/tools/example.ts:35-53 (handler)

  Handler implementation for 'example-tool' that extracts input, validates with Zod, processes via helper function, and returns the tool result.

  'example-tool': async (request) => {
    try {
      const { input } = request.params.arguments as { input: string }
      const inputSchema = z.object({
        input: z.string().min(1, 'Input must not be empty')
      })
      inputSchema.parse({ input })
      const result = await handleExampleProcess(input)
  
      return {
        toolResult: {
          content: [{ type: 'text', text: result }],
        },
      }
    } catch (error) {
      const errorMessage = error instanceof Error ? error.message : String(error)
      throw new Error(`Failed to process input: ${errorMessage}`)
    }
  }

• src/tools/example.ts:8-22 (schema)

  Tool schema definition for 'example-tool' including name, description, and input schema.

  const EXAMPLE_TOOL: Tool = {
    name: 'example-tool',
    description: 'An example tool that processes input data',
    inputSchema: {
      type: 'object',
      properties: {
        input: {
          type: 'string',
          description: 'Input string to process',
          minLength: 1
        }
      },
      required: ['input']
    }
  }

• src/index.ts:21-22 (registration)

  Combines example tools and handlers into global collections used by the MCP server for tool listing and execution.

  const ALL_TOOLS = [...EXAMPLE_TOOLS]
  const ALL_HANDLERS = { ...EXAMPLE_HANDLERS }

• src/index.ts:31-34 (registration)

  Registers the request handler for listing available tools, which includes 'example-tool' via ALL_TOOLS.

  server.setRequestHandler(ListToolsRequestSchema, async () => {
    log('Received list tools request')
    return { tools: ALL_TOOLS }
  })

• src/tools/example.ts:28-31 (helper)

  Helper function called by the tool handler to process the input string.

  async function handleExampleProcess(input: string): Promise<string> {
    log('Processing input:', input)
    return `Processed: ${input}`
  }