src/mcp-server.ts

import { Server } from '@modelcontextprotocol/sdk/server/index.js';
import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js';
import { CallToolRequestSchema, ListToolsRequestSchema } from '@modelcontextprotocol/sdk/types.js';
import { executeBackendAgentAction, BackendAgentAction } from './runtime.js';

const server = new Server(
  { name: 'sin-backend', version: '2026.03.22' },
  { capabilities: { tools: {} } },
);

server.setRequestHandler(ListToolsRequestSchema, async () => {
  return {
    tools: [
      {
        name: 'sin_backend_health',
        description: 'Check 2026 Elite Backend Architect readiness.',
        inputSchema: { type: 'object', properties: {} },
      },
      {
        name: 'sin_backend_code_generate',
        description: 'Generate Supabase and Agentic Backend architectures.',
        inputSchema: {
          type: 'object',
          properties: {
            prompt: { type: 'string' },
            contextDir: { type: 'string' },
          },
          required: ['prompt'],
        },
      },
      {
        name: 'sin_backend_code_review',
        description: 'Audit existing backends against 2026 standards.',
        inputSchema: {
          type: 'object',
          properties: {
            targetDir: { type: 'string' },
          },
          required: ['targetDir'],
        },
      },
    ],
  };
});

server.setRequestHandler(CallToolRequestSchema, async (request) => {
  try {
    let action: BackendAgentAction;

    if (request.params.name === 'sin_backend_health') {
      action = { action: 'sin.backend.health' };
    } else if (request.params.name === 'sin_backend_code_generate') {
      const args = request.params.arguments as any;
      action = { action: 'sin.backend.code.generate', prompt: args.prompt, contextDir: args.contextDir };
    } else if (request.params.name === 'sin_backend_code_review') {
      const args = request.params.arguments as any;
      action = { action: 'sin.backend.code.review', targetDir: args.targetDir };
    } else {
      throw new Error(`Unknown tool: ${request.params.name}`);
    }

    const result = await executeBackendAgentAction(action);
    return {
      content: [{ type: 'text', text: JSON.stringify(result, null, 2) }],
    };
  } catch (error: any) {
    return {
      content: [{ type: 'text', text: `Error: ${error.message}` }],
      isError: true,
    };
  }
});

export async function runMcpServer() {
  const transport = new StdioServerTransport();
  await server.connect(transport);
  console.error('A2A-SIN-Code-Backend MCP Server running on stdio');
}