DOOM MCP vs Recall

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.

Recall is a local-first multimodal semantic search tool that lets you find any file on your computer using natural language — images, PDFs, audio, video, and text — without any manual tagging, folder organization, or metadata. Ask "that invoice from the dentist last spring" or "photo of the whiteboard with the Q3 roadmap" and it surfaces the right file. Under the hood, Recall uses Google's Gemini Embedding 2 to generate semantic embeddings for all your files and stores them in ChromaDB, a local vector database that runs entirely on your machine. Nothing leaves your device. The Raycast extension adds a visual grid UI so you can search from anywhere on macOS without opening a terminal. First-run indexing can take 20-30 minutes for large libraries, but subsequent queries are near-instant. The project is MIT-licensed and built by a solo developer. It's a clear response to the frustration that Spotlight, Find, and Windows Search still rely heavily on filename and metadata matching even in 2026. As Gemini Embedding 2 is free within generous limits, the operating cost is essentially zero for personal use.