mcp-ui vs ext-apps
Interactive MCP tool interfaces compared
mcp-ui and ext-apps help connect interactive web interfaces to MCP tools for rendering in compatible hosts. mcp-ui provides SDKs for multiple server languages and supports MCP Apps alongside legacy MCP-UI resources, while ext-apps defines the MCP Apps protocol and offers a TypeScript SDK and examples.
mcp-ui: Build Interactive Interfaces for MCP Tools
mcp-ui provides SDKs for attaching web interfaces to Model Context Protocol tools and rendering them in compatible hosts. Use it when an MCP server needs interactive, sandboxed UI alongside tool results.
ext-apps: Add Interactive UIs to MCP Tools
MCP Apps is a specification and TypeScript SDK for serving interactive interfaces from MCP servers inside compatible AI chat clients. It helps server and client developers connect tool results to sandboxed, bidirectional UI experiences.
| mcp-ui | ext-apps | |
|---|---|---|
| Language | TypeScript | TypeScript |
| License | Apache-2.0 | NOASSERTION |
| Stars | 5.2k | 2.9k |
| Forks | 400 | 393 |
| Last analyzed | Oct 3, 2026 | Oct 3, 2026 |
Key differences
- mcp-ui includes server SDKs for TypeScript, Ruby, and Python, while ext-apps provides a TypeScript SDK.
- mcp-ui supports MCP Apps and legacy MCP-UI resources with separate rendering options; ext-apps focuses on the MCP Apps protocol and `ui://` resources.
- ext-apps includes React hooks, an app-bridge package, starter templates for several frontend frameworks, and Agent Skills; mcp-ui describes server and client SDKs and host-specific adapters.
- mcp-ui reports an Apache-2.0 license, while ext-apps metadata reports NOASSERTION and its README badge identifies Apache 2.0.
- ext-apps includes a basic reference host for examples, but describes it as unsupported for production; both projects require a compatible host to render interfaces.
- The supplied project facts report 5.2k stars for mcp-ui and 2.9k for ext-apps.
Choose mcp-ui if you…
- need Ruby or Python server SDKs for creating MCP UI resources.
- want to render legacy MCP-UI resources while adopting MCP Apps support.
- are building a compatible host and want TypeScript client components for rendering interfaces.
Choose ext-apps if you…
- want a TypeScript SDK centered on the MCP Apps protocol and bidirectional host-view communication.
- need starter templates for React, Vue, Svelte, Preact, Solid, or vanilla JavaScript.
- want to evaluate MCP Apps using examples and the included basic reference host.
Compare the numbers side by side, or add more projects
This comparison is generated with AI from the OSRepos analyses of both projects. Always check each project's repository and documentation before choosing.