Jannik Feuerhahn

I'm a software engineer currently building regulated medical software at Ada Health, with a frontend focus.

I became proficient at software engineering before LLMs. Now I'm learning how to do it again with AI agents.

Projects

keep-mcp

: The most popular open-source Google Keep MCP server by GitHub stars.

human-api

: Can an AI agent find a real person, pay them and get an answer, all on its own? Human API lets agents ask a closed question and pay per answer in USDC over x402.

llm-autobattler

: Two Generals is a medieval autobattler. Buy an army, write your tactics in plain words and watch them fight a friend's. An LLM compiles your orders into a program that runs the whole battle.

yt-sponsor-detect

: Can you fit a language model into a Chrome extension? A prototype that detects and skips sponsored segments on YouTube, entirely on your device.

heron-deterrent

: Built to fend off herons, with occasional friendly fire on magpies. The Reolink camera's on-device animal detection triggers a Home Assistant automation that sends a snapshot to Gemini as an AI Task with a structured verdict. A bird verdict opens a Zigbee water valve for 20 seconds and pushes a notification.

agent-box

: Claude Code and Codex share a container on my home server, and I steer both from my phone through the Claude and ChatGPT apps. When Codex hits its usage limit, a timer resumes the task once usage is available again.

feuer-io

: feuer.io is a multiplayer browser strategy game and my eternal pet project since 2018. I've used it to try different architectures, frameworks and hosting setups.

swift-raytracer

: A raytracer I wrote in Swift in 2021, with an iOS scene editor.

big-pond

: Big Pond is an iOS app for discovering local marine life, built after moving to Taiwan and wondering what was in the water.