MCP Server Boilerplate

import { GetPromptRequest } from '@modelcontextprotocol/sdk/types.js'; import { loggingContext, sendProgressNotification } from '@/core/server'; import { Prompt, PromptBuilder, PromptContext, PromptResult, } from '@/prompts/types'; import { EchoPromptInputSchema } from './types'; async function* executeEchoPrompt( request: GetPromptRequest, context: PromptContext ): AsyncGenerator<PromptResult> { const progressToken = context.progressToken; loggingContext.log('info', `Progress token: ${progressToken}`); loggingContext.setContextValue('prompt', 'echo'); try { loggingContext.log('info', 'Sending progress notification', { data: { request }, }); if (context.server) { await sendProgressNotification(context.server, { progressToken, progress: 0, total: 100, message: 'Starting echo prompt', }); } const { name: promptName, arguments: args } = request.params; loggingContext.log('info', 'Executing echo prompt', { data: { promptName, args }, }); // Validate arguments to be of type EchoPromptInput const validatedArgs = EchoPromptInputSchema.parse(args); const { message, repeat, uppercase } = validatedArgs; if (context.server) { await sendProgressNotification(context.server, { progressToken, progress: 100, total: 100, message: 'Echo prompt completed', }); } yield { messages: [ { role: 'user', content: { type: 'text', text: `Echo ${message ?? 'my message'}, repeat ${repeat ?? 1} times, ${uppercase !== '' ? `in uppercase` : ''}`, }, }, ], }; } catch (error) { loggingContext.log('error', 'Echo prompt execution failed', { data: { error: { message: error instanceof Error ? error.message : 'Unknown error occurred', stack: error instanceof Error ? error.stack : undefined, }, }, }); yield { messages: [ { role: 'user', content: { type: 'text', text: `Echo my message`, }, }, ], }; } } export const echoPrompt: Prompt<GetPromptRequest> = new PromptBuilder<GetPromptRequest>('echo') .description( 'Echo a message back with optional transformations, repetition, and structured output support' ) .arguments([ { name: 'message', description: 'The message to echo', required: true, }, { name: 'repeat', description: 'The number of times to repeat the message', required: false, }, { name: 'uppercase', description: 'Whether to convert the message to uppercase', required: false, }, ]) .processImplementation(executeEchoPrompt) .build();