I’m thrilled to share my recent success in integrating the Sutro water quality monitor into my Home Assistant setup! 
For those who aren’t familiar, Sutro is a device designed to monitor the water quality of hot tubs or pools, providing real-time data on temperature, pH, alkalinity, and chlorine/bromine levels. While Sutro doesn’t natively support Home Assistant integration, I decided to take matters into my own hands and reverse engineer their GraphQL API. 
After some meticulous research and coding, I managed to create a custom Home Assistant component that seamlessly connects Sutro to my smart home ecosystem. The process involved scraping the authentication token from the Sutro app’s network traffic and using it to securely access the device’s data. The best part? The token has a lifespan of approximately 996 years, so I won’t need to worry about refreshing it anytime soon! 
Here’s a glimpse of what I achieved:
I also created some custom gauges to display the water quality metrics in my Lovelace dashboard. While I’m planning to develop a dedicated custom card in the future, these gauges provide a clear and concise overview of my hot tub’s status. 
If you’re interested in replicating this setup, I’ve made the custom component publicly available on GitHub. Feel free to check it out and let me know if you have any questions or feedback! 
GitHub Repository: Home Assistant Sutro Integration
A huge thank you to the Home Assistant community for providing such a flexible and powerful platform that allows projects like this to thrive! 