Our Open Source Philosophy
Krill is free to use with source-available code synced daily to GitHub. Learn what's open, what you can build with it, and how to contribute.
Our Open Source Philosophy
Krill Is Free
Every Krill app — Android, iOS, Desktop, Web, and the Raspberry Pi server — is free to download and use. No subscriptions, no cloud fees, no feature gates. You install it, you own it, and your data never leaves your network.
Source-Available and Transparent
The Krill platform source code is synced daily to our public GitHub repository — the same Kotlin Multiplatform codebase that builds the apps you install. You can read the code, understand how your data flows, audit the security model, and learn from the implementation.
We chose a source-available model rather than a fully permissive license. This means:
- ✅ You can read, learn from, and reference the code
- ✅ You can build integrations, plugins, and automations on top of Krill
- ✅ You can fork and modify for personal use
- ✅ You can report bugs and submit improvements
- ❌ You cannot redistribute Krill or use the source to build a competing product
This lets us keep Krill free for users while sustaining the project long-term.
Fully Open Source Projects
Several parts of Krill are released under permissive open source licenses with no restrictions:
- krill-pi4j — A standalone gRPC service for Raspberry Pi GPIO, PWM, and I2C access via Pi4J. Use it in your own Java/Kotlin projects, even without Krill.
- Python Lambda examples — Ready-to-use scripts for sensors, actuators, CircuitPython boards, and hardware integrations.
- SVG dashboard templates — Diagrams and graphics you can use in your own projects or customize in Inkscape.
- SDK and CLI tools — Build your own custom integrations and automations with the Krill platform.
Contributions to these projects are welcome — fork, improve, and open a pull request.
Built on Open Source
Krill stands on the shoulders of exceptional open source projects, and we’re grateful to every one of them:
| Technology | Role in Krill |
|---|---|
| Kotlin Multiplatform | Shared codebase across all platforms |
| Compose Multiplatform | UI framework for Android, iOS, Desktop, and Web |
| Ktor | Server framework on Raspberry Pi |
| Pi4J | Hardware access for GPIO, I2C, SPI |
| H2 Database | Embedded time-series storage |
| Eclipse Mosquitto | MQTT broker integration |
| Firejail | Sandbox for Python Lambda execution |
When we find bugs or opportunities upstream, we contribute back. The krill-pi4j project itself started as a contribution to the Pi4J ecosystem.
Get Involved
- Browse the source: github.com/bsautner/krill-oss
- Report issues or request features: Issue Tracker
- Join the discussion: Reddit
- Share your build: We’d love to see what you automate with Krill — tag us or open a discussion on GitHub
If there’s a part of Krill you’d like to see fully open sourced, let us know. Our goal is to open as much as we can over time while keeping the project sustainable.
Last verified: 2026-04-07