Browserless × LangChain

Runnable Python and JS examples for the Browserless MCP server. Browserless is a stateful MCP server: a multi-turn browser agent works in a real ReAct loop over HTTP, not just batched single-call mode.

The hosted endpoint at https://mcp.browserless.io/mcp exposes 10 tools auto-importable via langchain-mcp-adapters — no partner package needed.

	Stateless tools (8)	Stateful tools (2)
	smartscraper, search, map, crawl, export, performance, function, download	agent, skill
Use case	Single-shot scraping, research, data extraction	Multi-turn browser automation, ReAct loops with persistent browser state

Multi-turn agent in Python: bind tools inside async with client.session(...) to keep the same MCP session across calls — see python/README.md. The JS adapter does this automatically.

Python

import os
from langchain_mcp_adapters.client import MultiServerMCPClient

client = MultiServerMCPClient({
    "browserless": {
        "transport": "http",
        "url": "https://mcp.browserless.io/mcp",
        "headers": {"Authorization": f"Bearer {os.environ['BROWSERLESS_TOKEN']}"},
    }
})
tools = await client.get_tools()
print([t.name for t in tools])  # 10 tools

See python/ for full notebooks: quickstart.ipynb, research_agent.ipynb, browser_agent.ipynb.

JS / TypeScript

import { MultiServerMCPClient } from "@langchain/mcp-adapters";

const client = new MultiServerMCPClient({
  mcpServers: {
    browserless: {
      transport: "http",
      url: "https://mcp.browserless.io/mcp",
      headers: { Authorization: `Bearer ${process.env.BROWSERLESS_TOKEN}` },
    },
  },
});
const tools = await client.getTools();
console.log(tools.map((t) => t.name)); // 10 tools

See js/ for full scripts: quickstart.ts, research_agent.ts, browser_agent.ts.

Get a token

account.browserless.io

Links

• Hosted MCP server: mcp.browserless.io
• Python adapter: langchain-mcp-adapters
• JS adapter: @langchain/mcp-adapters