---
title: "Model Context Protocol (MCP): definition | Agent MCP Directory"
description: "Model Context Protocol (MCP): A JSON-RPC 2.0 protocol in which hosts run clients that connect to servers offering tools, resources and prompts."
canonical: https://agentmcpdirectory.com/glossary/model-context-protocol
site: "Agent MCP Directory"
last_updated: 2026-11-04
section: "Glossary"
---

# Model Context Protocol (MCP): definition | Agent MCP Directory

> Model Context Protocol (MCP): A JSON-RPC 2.0 protocol in which hosts run clients that connect to servers offering tools, resources and prompts.

Source: https://agentmcpdirectory.com/glossary/model-context-protocol
Site: Agent MCP Directory
Last reviewed: 2026-11-04

# Model Context Protocol (MCP)

Model Context Protocol (MCP): A JSON-RPC 2.0 protocol in which hosts run clients that connect to servers offering tools, resources and prompts. Example: The current revision is dated 2026-07-28 and its schema lives at schema/2026-07-28/schema.ts. Also in the glossary is mcp-publisher: The CLI that publishes a server.json to the official registry after namespace verification.

## Definition

A JSON-RPC 2.0 protocol in which hosts run clients that connect to servers offering tools, resources and prompts.

## Example, with source

The current revision is dated 2026-07-28 and its schema lives at schema/2026-07-28/schema.ts. ([modelcontextprotocol.io](https://modelcontextprotocol.io/specification/latest), read 4 November 2026)

## Where it appears on this site

-   [MCP](https://agentmcpdirectory.com/standards/mcp/)
-   [Tool descriptions and agent success](https://agentmcpdirectory.com/guides/tool-descriptions-and-agent-success/)

## Neighbouring terms

-   [mcp-publisher](https://agentmcpdirectory.com/glossary/mcp-publisher/): The CLI that publishes a server.json to the official registry after namespace verification.
-   [Multi round-trip request (MRTR)](https://agentmcpdirectory.com/glossary/multi-round-trip-request/): The 2026-07-28 pattern where a server returns input\_required and the client retries the request with the answers.
-   [Namespace verification](https://agentmcpdirectory.com/glossary/namespace-verification/): Proof that a publisher controls a registry name, by GitHub login or OIDC for io.github names and DNS or HTTP for domains.

Edition

4 November 2026

Method

[How rows are verified](https://agentmcpdirectory.com/method/)

Data

[CSV and JSON](https://agentmcpdirectory.com/data/)

Markdown

[This page as markdown](https://agentmcpdirectory.com/glossary/model-context-protocol/index.md)

## Sources

-   [Source for the Model Context Protocol (MCP) example](https://modelcontextprotocol.io/specification/latest), read 4 November 2026

Last reviewed 4 November 2026