Marvin

My executive assistant that lets me take actions across my entire ecosystem of productivity apps with one line of written or spoken text.

What It Does

This started in the car. Siri kept hijacking my attempts to add tasks to Praxis so I made a custom executive assistant which can take actions across most of my app ecosystem. It can add or read back to-do items, add projects to the project manager and it has a modular architecture so I can add new abilities as needed.

How it works

The main realization and learning opportunity here was experimenting with some very low-powered AI models to just translate what I said into one of the available tasks with appropriate parameters. I cost compared different models and most of the cheapest ones can do the job fine.

Built with

Built with: Python + FastAPI orchestrating pluggable LLM adapters (Anthropic, Google Gemini, OpenAI-compatible) over a typed action registry, with deterministic date/recurrence normalization and fuzzy entity resolution against the live Praxis API; vanilla-JS single-file web UI plus a SwiftUI/iOS client.
Packaged in Docker and deployed behind Caddy on a Hetzner VPS at marvin.danji.wang, with a Click CLI for side-by-side model evals against a ~75-case dataset.