DOOM MCP vs Goose

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.

Goose is an open-source, extensible AI agent originally built by Block (formerly Square) and recently donated to the Agentic AI Foundation (AAIF) under the Linux Foundation. Written in Rust for performance and reliability, it runs locally and automates complex engineering tasks across 15+ LLM providers — including Anthropic, OpenAI, Google, Mistral, and Ollama for fully local operation. It ships with a desktop app (macOS, Linux, Windows), a CLI, and an API. The AAIF donation in early April 2026 put Goose alongside Anthropic's Model Context Protocol (MCP) and OpenAI's AGENTS.md spec as the foundation's inaugural projects — signaling serious intent to create neutral, vendor-independent governance for agentic AI standards. Block's engineering team cited wanting a "neutral home" for the agent as the open-source agent ecosystem matures. For teams that want an AI agent they can actually trust to run on local hardware without phoning home, Goose is the most mature option currently available. Its Rust architecture gives it a reliability and performance edge over Python-based alternatives, and multi-provider support means you're not locked into any one model vendor.