DOOM MCP vs ZeroClaw

Chris Nager built a fully playable DOOM that runs as an MCP (Model Context Protocol) app, rendering inline inside Claude and ChatGPT without a separate browser tab. The architecture uses two MCP tools — create_doom_session for inline-capable hosts and get_doom_launch_url as a browser fallback — combined with cloudflare/doom-wasm for the game runtime and a signed token system that maintains session state across both surfaces. The result is the same session whether you're playing inline or in a tab. The key technical challenge was avoiding iframe and CSP (Content Security Policy) issues. Rather than embedding a browser page inside the MCP iframe, the DOOM canvas runs directly inside the host's iframe — a subtle but critical distinction that resolved a class of rendering and input-handling bugs. The final implementation is intentionally stripped down: no save/load, no persistence adapters, just stable playable DOOM. Beyond the novelty, this project is a concrete demonstration that MCP apps are interactive surfaces, not just tool-calling JSON endpoints. The progressive enhancement pattern — same signed-token foundation serving both inline and browser modes — is a reusable architecture for any game or interactive experience that wants to live inside an AI assistant. Nager open-sourced the implementation and the blog post is a detailed technical breakdown.

ZeroClaw is a high-performance AI agent runtime built in Rust that targets the exact opposite end of the spectrum from OpenClaw's feature-heavy approach: a single static binary under 5MB that starts in under 10 milliseconds and runs anywhere from a Raspberry Pi to a Kubernetes cluster. It achieves this through a modular, trait-based architecture that lets you swap out only the components you actually need — bringing a full vector embedding engine, memory store, and agent harness to hardware that would choke on a Node.js runtime. The project ships with a built-in memory engine (vector embeddings + keyword search, no external dependencies), encrypted secrets management via local key files, and backwards compatibility with OpenClaw's markdown-based identity files through AIEOS (AI Entity Object Specification) support. There's also native WhatsApp integration for messaging-based memory — the kind of feature that signals this was built for real-world deployment, not just benchmarks. At operating costs 98% lower than traditional runtimes and a claimed 400x faster startup than OpenClaw, ZeroClaw is the runtime for builders who want to deploy AI agents on edge hardware, IoT devices, or just a cheap VPS without the overhead. The GitHub repo (github.com/openagen/zeroclaw) is open source and the project positions itself squarely as the "tiny but mighty" alternative in the rapidly expanding OpenClaw ecosystem.