DOOM MCP vs fff.nvim

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.

fff.nvim (Freakin Fast Fuzzy File Finder) is a high-performance fuzzy search plugin for Neovim that takes the standard file-search experience and rebuilds it for the era of AI coding agents. Beyond fast fuzzy matching, it ships with a built-in MCP server that lets Claude Code, Codex, and other agents call it directly — reducing token waste from repeated file glob patterns and directory listings. The token-efficiency angle is the differentiator. Every time an AI agent needs to find a file, it typically burns tokens on recursive directory listings or blind glob patterns. fff.nvim's frecency scoring (blending frequency + recency) and git-status awareness mean the agent gets the most relevant files in the first response, not after three rounds of narrowing. Prebuilt binaries in Rust make cold-start negligible even on large repos. The plugin supports three grep modes — plain, regex, and fuzzy — plus multi-select, configurable thread counts, and telescope-compatible keybindings. It's currently trending on GitHub with 3,700+ stars after a weekend Show HN that focused heavily on the agent-aware angle. The MCP integration is the hook that makes this more than a Telescope/fzf replacement.