npm-search-mcp-server
by btwiuse
#!/usr/bin/env node
import { Server } from '@modelcontextprotocol/sdk/server/index.js';
import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js';
import {
CallToolRequestSchema,
ErrorCode,
ListToolsRequestSchema,
McpError,
} from '@modelcontextprotocol/sdk/types.js';
import { exec } from 'child_process';
import util from 'util';
const execPromise = util.promisify(exec);
const isValidSearchArgs = (args: any): args is { query: string } =>
typeof args === 'object' && args !== null && typeof args.query === 'string';
class NpmSearchServer {
private server: Server;
constructor() {
this.server = new Server(
{
name: 'npm-search-server',
version: '0.1.0',
},
{
capabilities: {
tools: {},
},
}
);
this.setupToolHandlers();
// Error handling
this.server.onerror = (error) => console.error('[MCP Error]', error);
process.on('SIGINT', async () => {
await this.server.close();
process.exit(0);
});
}
private setupToolHandlers() {
this.server.setRequestHandler(ListToolsRequestSchema, async () => ({
tools: [
{
name: 'search_npm_packages', // Unique identifier
description: 'Search for npm packages', // Human-readable description
inputSchema: {
// JSON Schema for parameters
type: 'object',
properties: {
query: {
type: 'string',
description: 'Search query',
},
},
required: ['query'], // Array of required property names
},
},
],
}));
this.server.setRequestHandler(CallToolRequestSchema, async (request) => {
if (request.params.name !== 'search_npm_packages') {
throw new McpError(
ErrorCode.MethodNotFound,
`Unknown tool: ${request.params.name}`
);
}
if (!isValidSearchArgs(request.params.arguments)) {
throw new McpError(
ErrorCode.InvalidParams,
'Invalid search arguments'
);
}
const query = request.params.arguments.query;
try {
const { stdout, stderr } = await execPromise(`npm search ${query}`);
if (stderr) {
throw new McpError(
ErrorCode.InternalError,
`npm search error: ${stderr}`
);
}
return {
content: [
{
type: 'text',
text: stdout,
},
],
};
} catch (error) {
if (error instanceof McpError) {
throw error;
}
if (error instanceof Error) {
throw new McpError(
ErrorCode.InternalError,
`Unexpected error: ${error.message}`
);
}
throw new McpError(
ErrorCode.InternalError,
'Unexpected error occurred'
);
}
});
}
async run() {
const transport = new StdioServerTransport();
await this.server.connect(transport);
console.error('Npm Search MCP server running on stdio');
}
}
const server = new NpmSearchServer();
server.run().catch(console.error);