Fitbit · Renpho · Hevy · Claude AI — no code required
Ask your health data anything.
Connect your fitness devices. See everything on one dashboard. Then open Claude and ask questions in plain language — Why did my HRV drop? Am I recovering enough? Real answers from your real data.
Free forever. No credit card. Open source.
My HRV dropped from 48 to 28 over the last three days. What happened?
I checked your Fitbit vitals, Hevy workouts, and sleep data. Here's what I found:
- •You did deadlifts and squats on back-to-back days for the first time
- •Sleep efficiency dropped 12 points the night after
- •Resting heart rate is still 8 bpm above your baseline
How it works
Up and running in four steps.
Create an account
Sign up with Google or email. Takes 30 seconds.
Connect your devices
Link Fitbit, Renpho, and Hevy. Data flows automatically.
See your dashboard
15+ metrics in one place. Sleep, heart rate, workouts, body composition.
Ask Claude
Open claude.ai, connect TONND, and ask anything. No code needed.
Ask your data
Dashboards show data. Claude explains it.
Connect your TONND account in Claude.ai and ask questions in plain language. Claude pulls from your Fitbit, Renpho, and Hevy data and gives you answers no chart can.
My HRV dropped from 48 to 28. What did I do differently?
What's my sleep like on workout days vs. rest days?
My weight stalled for two weeks. What changed?
Am I gaining weight because I'm training less or sleeping worse?
Two accounts. Zero code.
Works with any Claude plan.
Connect
Bring your devices together.
Link Fitbit, Renpho, Hevy, and FatSecret. Data flows automatically into your dashboard.
Fitbit
Sleep stages, heart rate zones, activity, HRV, SpO₂, VO₂ Max, and 10+ metrics via OAuth.
Renpho Smart Scale
Weight, body fat, muscle mass, BMI, visceral fat, and full body composition.
Hevy
Workout tracking — exercises, sets, reps, volume, and muscle group analysis.
FatSecret
Food diary with calories, macros (carbs, fat, protein, fiber), and per-meal nutrition.
Track
Every metric that matters.
15+ health metrics in a single dashboard. Trends over days, weeks, and months.
Sleep
Stages, efficiency, and duration trends.
Activity
Steps, calories, distance, active zone minutes.
Heart Rate & HRV
Resting HR, zones, and recovery tracking.
Weight & Body Comp
Weight, body fat, muscle mass, BMI.
Workouts
Exercises, volume, muscle heatmap.
Recovery Score
Composite from HRV, sleep, and resting HR.
VO₂ Max & SpO₂
Cardio fitness and blood oxygen.
Nutrition
Calories, macros, and per-meal logs via FatSecret.
AI Analysis
Ask Claude anything about your data.
MCP Server
Connect Claude Desktop or claude.ai to query your data live.
Open source
Your data, your rules.
TONND is fully open source. Use our managed cloud or run it on your own server — you always own your data.
Open Source
AGPL-3.0 licensed. Read every line, contribute, or fork.
Self-Host Option
docker compose up. Run TONND on your own hardware if you prefer.
No Lock-in
Standard PostgreSQL. Export your data anytime.
Privacy
Your health data is personal.
TONND gives you full control. Use our cloud or self-host — either way, your data stays yours.
Privacy first
No tracking, no ads, no third-party data sharing. Your health data never enters a training dataset.
Your data
Standard PostgreSQL. Export or delete anytime.
Open code
AGPL-3.0 licensed. Inspect every line, including the AI server.
Self-host ready
Want full control? Run TONND on any machine with Docker.
From the blog
Latest posts
TONND now sees what you eat. The loop is closed.
I added FatSecret food diary sync to TONND alongside Fitbit, Renpho, and Hevy. Per-meal macros, full micros, and why nutrition was the missing piece.
Your health data can talk now. You just have to ask.
Health apps collect great data but can't answer questions. We connected TONND to Claude via the Model Context Protocol so you can ask your Fitbit, Renpho, and Hevy data anything in plain language.
Your HRV is trying to tell you something. Most people ignore it.
Heart rate variability is the most underused metric on your wrist. Here's what the research says about HRV, training, and recovery — and why I built a dashboard that puts it next to your workout data.
Your health data has stories to tell.
Connect your devices. Ask your questions. Free and open source.