trade-assistant/backend/app/services/mcp_search_server.py

import asyncio
import json
import logging
import os
import subprocess
from typing import List, Dict
import functools

from mcp.server.fastmcp import FastMCP

logger = logging.getLogger(__name__)
PROJECT_ROOT = os.path.abspath(os.path.join(os.path.dirname(__file__), "..", "..", ".."))
NODE_BIN = "/usr/bin/node"

BATCH_SCRIPT = r"""
const p = require('puppeteer');
(async () => {
  const queries = JSON.parse(process.argv[process.argv.length - 2]);
  const max = parseInt(process.argv[process.argv.length - 1] || '6', 10);
  const sk = ['bing.com','google.com','facebook.com','twitter.com','instagram.com','youtube.com','reddit.com','amazon.com','walmart.com','w3.org','whatsapp.com','wechat.com','qq.com','taobao.com','tmall.com','alipay.com','zhihu.com','baike.baidu.com','sogou.com','163.com','sohu.com','sina.com','iciba.com','cambridge','britannica','sciencedirect','mdpi.com','springer','wiley.com','acm.org','ieee.org','researchgate','semanticscholar','ncbi.nlm.nih','nature.com','oup.com','sagepub','tandfonline','pinterest','ebay','dictionary','translate'];

  try {
    const b = await p.launch({headless:true,args:['--no-sandbox','--disable-setuid-sandbox','--disable-blink-features=AutomationControlled'],timeout:10000});
    const allResults = [];
    const seenUrls = new Set();

    for (const q of queries) {
      try {
        const page = await b.newPage();
        await page.setUserAgent('Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36');
        await page.setExtraHTTPHeaders({'Accept-Language':'en-US,en;q=0.9'});

        const url = 'https://www.bing.com/search?q=' + encodeURIComponent(q) + '&setlang=en-US&cc=US';
        await page.goto(url, {waitUntil:'domcontentloaded',timeout:8000});
        await page.waitForSelector('.b_algo', {timeout:4000}).catch(()=>{});

        const results = await page.evaluate((m, sk) => {
          const found = []; const seen = new Set();
          document.querySelectorAll('li.b_algo').forEach(li => {
            const a = li.querySelector('h2 a'); if (!a) return;
            let url = (a.href || '').replace(/\/$/,'');
            if (!url.startsWith('http') || seen.has(url)) return;
            seen.add(url);
            if (sk.some(d => url.includes(d))) return;
            const hostname = url.replace(/^https?:\/\//,'').split('/')[0];
            if (hostname.endsWith('.edu') || hostname.endsWith('.ac') || hostname.endsWith('.gov')) return;
            const title = (a.textContent||'').trim().substring(0,100);
            const s = li.querySelector('.b_caption p, .b_lineclamp2');
            found.push({title, url, snippet:s?s.textContent.trim().substring(0,200):''});
          });
          return found.slice(0,m);
        }, max, sk);

        for (const r of results) {
          if (!seenUrls.has(r.url)) {
            seenUrls.add(r.url);
            allResults.push(r);
          }
        }
        await page.close();
      } catch(e) { /* skip failed query */ }
    }
    console.log(JSON.stringify(allResults.slice(0, max * queries.length)));
    await b.close();
  } catch(e) { console.log('[]'); }
})();
"""


BATCH_SCRIPT_FILE = os.path.join(os.path.dirname(__file__), "_batch_search.js")
NODE_MODULES = os.path.join(PROJECT_ROOT, "node_modules")


async def search_bing_batch(queries: List[str], max_per_query: int = 6) -> List[Dict[str, str]]:
    loop = asyncio.get_running_loop()
    try:
        with open(BATCH_SCRIPT_FILE, "w") as f:
            f.write(BATCH_SCRIPT)
        env = os.environ.copy()
        env["NODE_PATH"] = NODE_MODULES
        fn = functools.partial(
            subprocess.run,
            [NODE_BIN, BATCH_SCRIPT_FILE, json.dumps(queries), str(max_per_query)],
            capture_output=True, text=True, timeout=120, cwd=PROJECT_ROOT, env=env,
        )
        result = await loop.run_in_executor(None, fn)
        for line in result.stdout.strip().split("\n"):
            line = line.strip()
            if line.startswith("["):
                return json.loads(line)
        return []
    except subprocess.TimeoutExpired:
        logger.warning("Bing batch search timed out")
        return []
    except (json.JSONDecodeError, Exception) as e:
        logger.warning(f"Bing batch search error: {e}")
        return []


async def search_bing(query: str, max_results: int = 10) -> List[Dict[str, str]]:
    return await search_bing_batch([query], max_per_query=max_results)


mcp = FastMCP("trade-search", log_level="WARNING")


@mcp.tool(
    name="web_search",
    description="Search the web for companies, buyers, or business information. Returns title, URL, and snippet for each result. Useful for finding potential customers, researching companies, or gathering market intelligence.",
)
async def web_search(query: str, max_results: int = 10) -> str:
    results = await search_bing(query, max_results)
    if not results:
        return json.dumps({"results": [], "error": None})
    return json.dumps({"results": results, "error": None})


def main():
    asyncio.run(mcp.run_stdio_async())

if __name__ == "__main__":
    main()