How to connect a Renpho scale to AI (Claude and ChatGPT)

Start with the honest part, because it is the whole point. There is no direct link between your Renpho scale and Wellness Project, we do not run a Renpho API, and this is not the hobbyist Renpho MCP server that circulates on GitHub. Your Renpho scale talks to the Renpho Health app, and Renpho Health writes those readings into the health hub already built into your phone: Apple Health on iPhone, Google Health Connect on Android.

Wellness Project reads that hub. It takes the weight and body composition Renpho deposited there, structures them into one continuous history, and serves that history to Claude and ChatGPT over a single MCP connection. So the real chain is Renpho Health to Apple Health or Health Connect, then Wellness Project, then Claude or ChatGPT. We never touch Renpho directly, and we do not pretend to.

There is an open-source Renpho MCP server floating around developer forums, and it is a genuinely clever piece of work. It is also built for engineers: you clone a repository, hand it your Renpho credentials, run it yourself, and it hands back raw numbers for one brand of scale. Wellness Project is the opposite tradeoff for people who do not want a side project. It is an app you download, it reads whatever your phone hub already holds, so your Renpho weight sits next to your wearable, your runs, and your logged meals, and when you ask about a trend it draws a live chart in the chat instead of dumping JSON. Same goal, no repo to maintain, nothing to re-authorize by hand.

Routing through Apple Health or Health Connect is not a workaround, it is the sturdier design. The hub is the one place Renpho already maintains a permission to write to, so there is no extra token to babysit and nothing to re-authorize every few weeks. When Renpho ships an app update, your data keeps flowing because the contract is between Renpho and the phone, not between Renpho and us.

It also means every other device you own can join the same history. The Renpho scale reports your morning weight and body composition, an Apple Watch or Oura ring reports the sleep and recovery, and your workouts and meals sit in the same record. Wellness Project reads the whole picture, so your AI coach sees body composition next to training load next to nutrition, instead of one number in isolation.

The setup is short because the phone does the heavy lifting. Name the hub first, let Wellness Project read it, then point Claude or ChatGPT at your account.

That is the entire flow. No Renpho login on our side, no real-time promise we cannot keep. Freshness tracks whenever the Renpho Health app syncs to your hub, and Wellness Project reads it from there.

On iPhone, the Renpho Health app writes weight, body fat percentage, BMI, and lean body mass to Apple Health, and Wellness Project reads them from there. This path is mature and reliable. Some of Renpho's deeper readings (visceral fat, bone mass, and the like) stay inside the Renpho app because Apple Health has no field for them, but the core body-composition set carries over cleanly.

On Android, aim for Health Connect, not Google Fit. Renpho now offers a Health Connect option in the Renpho Health app, and that is the path to pick, because Google is sunsetting the older Google Fit APIs at the end of 2026. A lot of Renpho's own help pages and third-party walkthroughs still say "Google Fit"; treat that as the stale instruction to watch. If you connect through Google Fit only, your scale data can be stranded when those APIs go away, so open the Renpho Health app, look for the Health Connect option, and route through it. Either way you add exactly one connector to Claude or ChatGPT and read everything in one place.