What is MCP (Model Context Protocol)? A plain-language guide

Model Context Protocol (MCP) is an open standard — originally developed by Anthropic — that lets AI assistants connect to external tools and data sources in a consistent way. Instead of every app building custom integrations for ChatGPT, Claude, and Cursor, MCP provides a shared interface.

The problem MCP solves

AI assistants are powerful, but they start each conversation with no memory of your personal data. Connecting them to your bookmarks, notes, or files traditionally required custom plugins, brittle scrapers, or copy-pasting context by hand.

MCP standardizes this: your AI assistant discovers what tools are available, calls them with structured requests, and receives structured responses. Think of it as a USB port for AI — one connector shape that many devices can use.

How MCP works in practice

An MCP setup has three parts:

• Host: The AI application — Claude Desktop, Cursor, or another MCP-compatible client.
• Server: A service that exposes tools and data — for example, your CapturedIt library via the Context Hub.
• Protocol: JSON-RPC messages that define available tools, handle authentication, and return results.

When you ask a question, the host decides whether to call an MCP tool (like “search my library”), sends the request to the server, and incorporates the results into its response.

What you can do with MCP and a knowledge base

• Search your saved links, notes, and files by concept — not just keyword
• Retrieve full content from specific items for deeper analysis
• Save new captures back to your library from within the AI conversation
• Ask synthesis questions across months of accumulated research

MCP vs REST API

MCP is designed for AI-native clients that need to discover and invoke tools dynamically. A REST API (like CapturedIt’s Context Hub) is better when you are building a specific integration — a Custom GPT action, a Slack bot, or your own app. Many workflows use both: REST for structured app integrations, MCP for conversational AI tools like Claude and Cursor.

Getting started

CapturedIt Vault includes MCP access to your library. Setup instructions are in Dashboard → Integrations. For a step-by-step walkthrough of ChatGPT and Claude connections, see our guide on connecting bookmarks to ChatGPT and Claude.