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Ext-apps Alternatives
Similar projects and alternatives to ext-apps
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claude-code
Claude Code is an agentic coding tool that lives in your terminal, understands your codebase, and helps you code faster by executing routine tasks, explaining complex code, and handling git workflows - all through natural language commands.
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Puter.js
Puter.js - The Backend for AI-Generated Apps. One-shot full-stack apps with your existing AI coding tool. Puter.js gives you Auth, Storage, DB, AI & more, with up to 90% fewer AI tokens than other backend platforms.
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sunpeak
Server-agnostic MCP testing framework and full-stack MCP App framework for ChatGPT Apps, Claude Connectors, and more.
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SaaSHub
SaaSHub - Software Alternatives and Reviews. SaaSHub helps you find the best software and product alternatives
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skybridge
Skybridge is a full-stack TypeScript framework for MCP Apps and ChatGPT Apps. Type-safe. React-powered. Platform-agnostic.
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mcp-agentic-ui
Discontinued Visual interface for AI agents beyond text-only chat [Moved to: https://github.com/Zabaca/pane]
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mcp-app-template
Template ChatGPT app - Designed to be modified by Claude Code or other coding agents
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ext-apps
Official repo for spec & SDK of MCP Apps protocol - standard for UIs embedded AI chatbots, served by MCP servers (by dalenguyen)
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SaaSHub
SaaSHub - Software Alternatives and Reviews. SaaSHub helps you find the best software and product alternatives
NOTE:
The number of mentions on this list indicates mentions on common posts plus user suggested alternatives.
Hence, a higher number means a better ext-apps alternative or higher similarity.
ext-apps discussion
ext-apps reviews and mentions
Posts with mentions or reviews of ext-apps.
We have used some of these posts to build our list of alternatives
and similar projects. The last one was on 2026-04-24.
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I used Ember.js to make an MCP server
The bundle size is larger than desired, but much of that is actually the MCP Apps SDK, which bundles every locale of zod.
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Building MCP Apps with Angular
If you've been building MCP servers, you know the drill: your tool returns JSON, the host renders it as text, and the user squints at a timestamp string. MCP Apps change that — they let your server ship an interactive UI that the host renders in an iframe, right inside the conversation.
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MCP vs Skill: An Evolutionary Perspective
MCP isn't standing still either. MCP Apps is a fascinating development — it extends the protocol to deliver interactive UIs (charts, forms, dashboards) inline in the conversation, with bidirectional communication between the agent and the UI.
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5 Tips for Building MCP Apps That Work
There's a lot that also goes on behind the scenes, such as View hydration, capability negotiation, and CSPs, but this is how it works at a high level. If you're interested in the full implementation of MCP Apps, we highly recommend giving the spec a read.
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sunpeak is all-in on MCP Apps
That changed when OpenAI contributed to and aligned on MCP Apps as the open standard. The rendering model, the iframe sandbox, the UI functionality — all of it became portable. And as of February 2026, the major hosts actually implemented it.
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Show HN: MCP App Template designed for coding agents
Hi, author of the repo speaking here!
When I tried building MCP Apps [1], the official repos (https://github.com/openai/openai-apps-sdk-examples, https://github.com/modelcontextprotocol/ext-apps/tree/main/e...) were great starting points, but they're designed for human developers. When I used them with Claude Code, I ended up in the usual loop: agent writes code → I manually test the app on ChatGPT → describe errors back → repeat. Plus, we didn't know what the best practices are, and struggled to enforce them.
So I built an MCP App template designed for coding agents to work as autonomously as possible on an MCP app.
The key idea: orthogonal testing. 450+ tests parameterized across 12 widget modules that verify infrastructure (protocol compliance, best practices grade, browser rendering), not business logic. Modify widgets, change data, add features — the tests should still pass. Agents iterate freely and get feedback without a human in the loop.
Other features:
- Running a SPA inside ChatGPT using MCP Apps (Step-by-Step Guide)
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Visual UIs Are Now Possible in MCP Servers
The @modelcontextprotocol/ext-apps library lets MCP tools return visual UIs. When you call a tool, instead of just getting text back, you get an interactive iframe rendered inline in the conversation.
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I Reverse Engineered ChatGPT Apps Iframe Sandbox
MCP Apps spec (sandbox proxy section)
- MCP Is a Fad
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A note from our sponsor - Puter.js
developer.puter.com | 20 Jul 2026
Stats
Basic ext-apps repo stats
16
2,591
9.7
4 days ago
modelcontextprotocol/ext-apps is an open source project licensed under GNU General Public License v3.0 or later which is an OSI approved license.
The primary programming language of ext-apps is TypeScript.
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Puter.js - The Backend for AI-Generated Apps
One-shot full-stack apps with your existing AI coding tool. Puter.js gives you Auth, Storage, DB, AI & more, with up to 90% fewer AI tokens than other backend platforms.
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