DOOM running in ChatGPT and Claude
I made a playable DOOM MCP app that can launch inline inside compatible AI clients like ChatGPT and Claude, and falls back to a browser URL everywhere else.
MCP apps are "interactive UI applications that render inside MCP hosts like Claude Desktop."
The final version is intentionally lean:
There’s something delightful about taking a protocol designed for tools and structured interactions, and asking: “ can it run DOOM? ”
MCP apps are a progressive enhancement. So the app has two jobs:
A lot of the work was not “can I make DOOM run in a browser?” That part is well-trodden territory. The harder part was making the same session work across different clients with different rules around iframes, CSP, and UI rendering.