Mathis Arends mathisarends

Münster, Germany | currently doing my M.Sc. in Information Systems @ FH Münster

Building Python libraries and developer tools for typed APIs, generated clients, and working with coding agents.

Currently building Canon: a FastAPI stack for HTTP contracts, typed SSE, WebSocket RPC, and generated clients.

APIs, Codegen & Developer Tooling

🏛️ canon - One FastAPI workspace for architecture guides, feature composition, typed SSE, and WebSocket RPC; packages remain independently installable
🧱 fastapi-canon - Feature composition, Dishka dependency injection, and typed HTTP success/error contracts
🔌 fastapi-wsrpc - FastAPI-first WebSocket RPC with OpenRPC and generated Python/TypeScript clients; unreleased successor to pyrpckit, whose original repository remains available
🔌 pyrpckit - Define typed Python RPC protocols with schema export and generated clients
🌊 fastapi-streams - Decorate FastAPI SSE endpoints, generate typed TypeScript and Python clients, and catch contract drift in CI
🧩 lit-query-codegen - Generate typed TypeScript clients and TanStack Lit Query options from OpenAPI
🐍 httpxgen - Generate typed async HTTPX clients from OpenAPI
⚒️ smelt - Architecture guardrails for Python: import boundaries, test mirroring, and change-aware checks for reviewing agent changes

🤖 callm - Type-safe Python library for OpenAI, Azure OpenAI and Codex
🔍 retrieverkit - Provider-agnostic RAG building blocks for Python - chunking, dense/lexical retrieval, and rank fusion behind small abstract ports, zero core dependencies
🧰 agenttoolkit - One provider-neutral definition for tools exposed to LLM agents - schema, availability, metadata, and execution logic in one place
💰 tokenary - LLM API cost calculation based on the LiteLLM model catalog

🌐 browsertunnel - Mirrors a real Chromium tab into a web page over a single WebSocket - CDP-driven screencast, full clipboard/tab sync, and imitated input, built on cdpify and pyrpckit
🪐 browserplane - Browser provisioning platform inspired by Browserbase: lease and remotely control real Chromium sessions in a web UI
🧬 cdpify - Type-safe Chrome DevTools Protocol client with Pydantic models, including a codegen tool that generates the client straight from the CDP specification

🧠 cara - Voice/CLI conversational agent with a JSON-RPC gateway and pluggable agent runtime
🗣️ rtvoice - Framework for real-time voice agents on OpenAI's Realtime API
🎤 vocalbin - Typed async adapters for speech-to-text, text-to-speech, realtime transcription, and translation
👂 wakewordkit - Wake word detection built on openWakeWord, with a pluggable audio input API

🔊 sonosify - Sonos control over UPnP and the S2 API, with a Cloud Integration (playback, queue, groups, events)
💡 hueify - Typed async Python client for Philips Hue CLIP v2, with one API for lights, rooms, zones, scenes, and events
🌅 huerise - Philips Hue sunrise alarm with audio, REST API, and an agent-friendly CLI

📚 arxcli - Fast, minimal, script-friendly CLI for researching papers on arXiv, with human-readable tables and JSON/JSONL for agents
🎧 spoti - Go CLI for Spotify, backed by the official Web API via OAuth PKCE, no cookie scraping - agent-friendly JSON output
📊 go-withings - Script-friendly CLI for the Withings API - OAuth, weight & body composition, human-readable or JSON output
⌚ fitbitctl - Read-first Go CLI for Fitbit/Pixel Watch health data via Google Health API v4, OAuth 2.0 + PKCE, JSON output
🔉 elevenfx - Go CLI for generating sound effects with the ElevenLabs API
💡 huego - Go CLI for Philips Hue bridges, talking directly to the local CLIP v2 REST API

🎴 prompster-cli - Generate Hitster-style card decks from natural language prompts and Spotify
🎮 prompster-frontend - Web app for playing with self-made Hitster cards
🎵 spotifyify - Typed async Spotify client for Python

🎬 fh-muenster-slidev-starter - Slidev starter for FH Münster presentations with a component library and style guide in FH corporate design