firasd14 hours ago
Interesting experiment!
I think tool calling (such as MCP) is really underrated. People think of it as a way to connect to Google Drive etc but the potential for MCP to power actual in-chat apps is very under-explored.
I've been working on something called Liveclip which is like tables in chat: just a few hours ago I implemented a way for ChatGPT (etc) to surface sentences within the US Constitution: https://x.com/firasd/status/2049187034066198658
I've also thought that games are an obvious way to explore chat-native MCP apps. Hangman for example. Also small utilities like a clock. In fact I have a no-auth remote MCP clock that can be added to any client right now deployed straight from https://github.com/firasd/mcpclock to https://mcpclock.firasd.workers.dev/mcp <-- works in Claude .ai, Claude iOS, Claude Code, Codex, etc right now
_pdp_15 hours ago
Cool, but yes you can render whatever you want as long as you register an MCP resource and use it as part of a tool call. It is just html in an iframe.
JambalayaJimbo6 hours ago
This is cool! I'd love if you could explain the issues you had with CSP and serving content.
I was just tinkering around with MCP Apps the other day, and I had a really hard time serving images (this is for rendering in VSCode Copilot). Did you serve static resources through resource endpoints in the mcp server, or via another mechanism?
ghstinda8 hours ago
I remember when this game came out, there was nothing that felt like it, but Shadow Warriors was pretty cool. Doom was special just because it felt right and the rhythm just flowed as you went deeper.
avaer15 hours ago
The title is misleading. This is in ChatGPT but not on ChatGPT. It's not running on AI. It's running on a site that serves an AI chatbot.
Still very cool though.
I suppose most people don't know this, but you can render web resources into chat harnesses via MCP apps [1]. The actual DOOM part of this runs on [2].
[1] https://modelcontextprotocol.io/extensions/apps/overview [2] https://github.com/cloudflare/doom-wasm
dang15 hours ago
Ok, we've switched the title above to a hopefully-clearer phrase from the article's first sentence.
chrisnagerop14 hours ago
Works for me! Thanks for updating.
Title changed from “DOOM runs in ChatGPT and Claude” to “A playable DOOM MCP app”.
kang14 hours ago
somebody did this a month ago https://www.youtube.com/watch?v=fdbXNWkpPMY
i am increasingly going schizo, where every single thing I post/see posted gets copied and karma farmed on social media. further, any novelty I share with an llm gets eaten/absorbed by the harness as a feature.
[deleted]12 hours agocollapsed
nurettin6 hours ago
right? I've had that feeling dozens of times during summer 2025 with the earliest claude cli. It would fail, I'd fix the bug, next session when I ask it to solve the same problem, it would succeed!
gHA514 hours ago
Timestamp?
chrononaut13 hours ago
I am not sure if it aligns to the approach in OP's article but it's the last ~minute or two of the linked video.
phodo15 hours ago
Great work. I wonder what the future "can it run doom ?" Will it be: Can it run AGI on a new quantum processor/ robot / bio-engineered cell. Or will it be Doom all the way down...
alach1115 hours ago
Snake and DOOM were two of our early tests (for filter functions and MCP) when we stood up Open WebUI for internal chat/agent use. Sometimes games are the best way to limit-test new tech.
chrisnagerop15 hours ago
That’s awesome. Yes!
eigenblake14 hours ago
I put Bad Apple in an MCP App two weeks ago https://youtu.be/YFF5H886slQ
david_shi10 hours ago
what interfaces would this work on?
in-app for chatgpt, TUIs (https://www.youtube.com/watch?v=fdbXNWkpPMY, from another comment in the thread), anything else?
neosat14 hours ago
Apart from a cool project, this evolved my perspective on what an MCP is, along with some cool architecture insights and inspiring ideas. Thank you!
chrisnagerop14 hours ago
Glad to hear it! This stuff is fascinating and rapidly evolving. I’ve been learning by doing. Happy hacking.
throwawayk7h14 hours ago
Was a little disappointed that this didn't result in the agent playing Doom itself over MCP.
Still this is very cool! (And if that had been what you'd implemented, my disappointment would have been that it wasn't the reverse. :P Can it do both?)
_oxxa15 hours ago
I was not too surprised to see DOOM running on a pregnancy test before but seeing it on an MCP was really unexpected ;)
2ndorderthought15 hours ago
It's still fun but it feels gross. Like here is this monstrosity of compute running the thing we are running in toothbrushes.
nsxwolf15 hours ago
I read this and I did not understand it. An MCP is synthesizing DOOM frames from a training set? What is this doing
Ethee15 hours ago
It took me a reread and some thinking to realize what was going on. The 'MCP app' he's referring to here is basically a browser front-end replacement like electron. So what he's doing here is running DOOM as apart of that browser run-time and passing it through to the front-end. It's less "playing DOOM through the AI" and more "Playing DOOM while the AI can watch".
munchler14 hours ago
Thank you for this explanation. So the AI can respond based on the DOOM game that it’s watching? E.g. Could you ask the chatbot for advice on what to do next on the current game level?
Ethee13 hours ago
Kind of? Even watching is probably a bit of a stretch here. The point of an MCP server is to be a sort of AI translator for whatever you're inputting. Here we're inputting an iframe that's running a wasm binary. So I imagine in theory all the AI sees is the actual iframe and whatever is in memory currently for the wasm game. Funny enough without some sort of screenshot tool on top of this I'm not sure the AI can actually 'see' the game at all.
nilslice15 hours ago
its basically an iframe embedding doom on a remote webpage
awesome_dude15 hours ago
Best capability test there is
wingi9 days ago
simply great!
chrisnagerop14 hours ago
Appreciate it. I had fun building.
huflungdung15 hours ago
[dead]
ashrodan15 hours ago
Love it! MCP apps is still new and under-utilised and we need to understand it's boundaries and compatibility.
chrisnagerop15 hours ago
For sure.