> ## Documentation Index
> Fetch the complete documentation index at: https://docs.byul.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# MCP Introduction

> Overview and architecture of @byul/mcp

## What does it provide?

`@byul/mcp` exposes Byul's REST API through MCP tools and resources over stdio.

* **Tool**: `news_fetch` – proxies `GET /news` (filters and pagination)
* **Resource**: `byul://news{?limit,cursor,sinceId,minImportance,q,symbol,startDate,endDate}`
* **Response format**: summary string + original JSON payload

## Requirements

* Node.js 18+
* `BYUL_API_KEY` environment variable (e.g., `byul_api_key`)

## Architecture

<Steps>
  <Step title="Register the MCP server">
    Register `@byul/mcp` in your MCP-compatible client.
  </Step>

  <Step title="Communicate via stdio">
    The client launches the server via stdio and uses JSON-RPC over stdin/stdout.
  </Step>

  <Step title="Proxy to Byul REST API">
    Tool/resource calls are forwarded to Byul endpoints and returned as-is with a summary.
  </Step>
</Steps>