---
title: "MCP Apps"
canonical: "https://canmyagentuse.com/specs/mcp-apps"
contentKind: "specification"
locale: "en"
description: "Stable MCP extension for interactive interfaces returned by tools and rendered by compatible hosts."
llmSummary: "MCP Apps is an MCP extension for ui resources and sandboxed interactive interfaces. A host can support MCP tools without supporting MCP Apps."
publishedAt: "2026-08-28T00:00:00.000Z"
updatedAt: "2026-08-28T00:00:00.000Z"
verifiedAt: null
tags: ["mcp","ui","apps","protocol"]
---

# MCP Apps

MCP Apps is an MCP extension for ui resources and sandboxed interactive interfaces. A host can support MCP tools without supporting MCP Apps.

- HTML: https://canmyagentuse.com/specs/mcp-apps
- JSON: https://canmyagentuse.com/api/v1/specs/mcp-apps.json
- Markdown: https://canmyagentuse.com/specs/mcp-apps.md

MCP Apps defines an interactive UI layer on top of MCP. The host discovers a declared UI resource, renders it in an isolated frame, and mediates communication with the tool and host.

Tool calling and app rendering remain separate catalog capabilities. Host listing, plan availability, developer-mode access, sandbox behavior, and extension revision should remain visible in the evidence.

## Revision identity

- Authority: MCP project
- Revision: 2026-01-26
- Maturity: stable extension
- Structure: MCP extension, ui resource, and sandboxed frame
- Canonical specification: https://modelcontextprotocol.io/extensions/apps/specification
- Roles: host, server, app