LangChain

install langchain-megalania, then MegalaniaLoader(urls).load() for documents and megalania_tools() for an agent. The key comes from MEG_API_KEY. Blocked pages and errors are free.

Install

Python 3.10 or newer.

pip install langchain-megalania

Documents

MegalaniaLoader reads each URL as Markdown. Each document’s metadata has source, request_id, credits_charged and target_status.

from langchain_megalania import MegalaniaLoader

docs = MegalaniaLoader(["https://docs.megalania.io/"]).load()
print(docs[0].metadata["credits_charged"], docs[0].page_content[:200])

Pass any key of the JSON envelope as a keyword, for example country_code="DE" or response_types="text".

A blocked page raises MegalaniaError with code blocked. With continue_on_failure=True the loader skips it, logs the code and the request id, and goes on.

A whole site

crawl runs a batch from one start page and waits for it. Each document is one page the crawl reached, with source, depth and target_status.

from langchain_megalania import MegalaniaLoader

docs = MegalaniaLoader("https://docs.megalania.io/", crawl={"max_pages": 20, "max_depth": 2}).load()
print(len(docs), [d.metadata["source"] for d in docs][:5])

Tools for an agent

megalania_tools() returns five tools: scrape, extract, map_site, create_batch and get_batch. Their inputs use the same names as the API.

from langchain_megalania import megalania_tools

scrape = megalania_tools()[0]
print(scrape.invoke({"url": "https://docs.megalania.io/"})[:300])

Give them to any LangChain agent:

from langchain.agents import create_agent
from langchain_megalania import megalania_tools

agent = create_agent("openai:gpt-5", tools=megalania_tools())
agent.invoke({"messages": [{"role": "user", "content": "What can the API at https://docs.megalania.io/ do?"}]})

Each page costs at most 128 credits by default. That covers every route, and a residential Chrome page up to about 1.5 MiB. A bigger page comes back cut, with a note that says so. Pass megalania_tools(max_credits=...) (up to 32767) to allow more. max_credits is per page, so a batch can cost up to max_credits times its pages: one create_batch call takes at most 100 pages by default. More URLs are refused, and a crawl stops at 100 pages. Pass megalania_tools(max_pages=...) to allow more. The agent can raise neither. max_chars (default 100,000) cuts what a tool returns, so one page cannot fill the context.

LangChain.js

There is no separate JavaScript package. Connect our MCP server with @langchain/mcp-adapters:

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

const client = new MultiServerMCPClient({
  megalania: { url: "https://mcp.megalania.io/", headers: { Authorization: `Bearer ${process.env.MEG_API_KEY}` } },
});
const tools = await client.getTools();

The code is MIT licensed at https://github.com/megalania/megalania-python.