Fog

Inspiration

I was mid-run in a progression game, alt-tabbed for one craft answer, and the wiki spoiled a boss I hadn't fought. Asking chat made up recipes. I wanted a helper that only knows what I've unlocked.

What it does

Fog is a second-monitor companion for that kind of game. You mark bosses beaten and what you're carrying. An agent talks to the page through WebMCP — craft, housing, what's next. Later stages aren't registered as tools, so it can't pull them.

How it's built

Vite, React, TypeScript. Hosted static on Vercel.

Eleven WebMCP tools via document.modelContext.registerTool. Eight always on. Three flip with your stage (craft list, recipe lookup, hints) using AbortController.

Game data and gating live in the page. Demo scenarios so judges can poke it without owning the game.

Challenges

WebMCP only shows up in the right browser (ChatGPT in-app or Chrome with the flag). The model may still recall the game from training — we only control what the page tools expose. Filming a demo without a live install meant fake scenarios and a stand-in screenshot.

Try it

https://stratagem-opal.vercel.app
https://github.com/sivaratrisrinivas/stratagem

Built With

• react
• typescript
• vercel
• vite
• webmcp