Solair AI vs MetricBridge: On-Device Apple Health Q&A, and the Agent Bridge Only One Ships
Two on-device apps that answer questions about your Apple Health data without sending it to the cloud. One is free. The other costs $24.99 once and gives you something the first never will: a way to hand that same data to your own AI agents.
Quick answer. Solair AI is a free, genuinely private on-device assistant that reads 15+ Apple Health metrics and answers questions on your iPhone. MetricBridge answers the same questions on-device, shows you the exact numbers it used, and then exports 190 metrics to your own agents over a zero-dependency MCP server. If all you want is chat, either works. If you want your health data to power Claude, Cursor, or your own scripts, only MetricBridge gives you the bridge.
What Solair AI does well
Solair (solairai.app) is a local-first AI assistant for iPhone and iPad. It runs 60+ on-device models on Apple's Neural Engine, needs no account, collects nothing, and is free. Its Health Intelligence feature reads Apple HealthKit directly on-device, analyzing 15+ metrics: steps, heart rate, sleep stages, workouts, VO2 max, HRV, exercise time, standing hours, and walking steadiness. There's a Recovery Score and correlation insights too, all computed on the phone. Your health data stays on your phone, which is exactly what you want from a private health AI.
If your bar is "ask my body questions in plain English without uploading anything", Solair clears it. It's a good app, built by one developer who clearly cares about privacy.
What MetricBridge does
MetricBridge is the same idea with a second layer. The Ask and Pro chat answer questions about your Apple Health data on-device, and every answer carries a provenance card that shows the numbers behind it, so you can check the work instead of taking a smooth paragraph on faith. A Weekly Brief summarizes your week from the same local data. Nothing is uploaded, and there's no cloud account.
Then comes the part Solair doesn't have. MetricBridge exports 190 Apple Health metrics to a folder you pick (iCloud Drive, a synced folder, your LAN, or a webhook you run) and points a zero-dependency MCP server at it. Any MCP client (Claude, Cursor, ChatGPT, opencode, and more) can then query those metrics through 14 read-only tools. Your data never transits the MCP server author's infrastructure, and you keep whichever model you already use.
The gap: a chat loop you can't leave
Here's my honest read. Solair's health feature is a closed loop. You ask questions inside Solair, Solair answers, and that's the end of the road. There's no MCP server, no health-data export, and no way to feed your steps or HRV into Claude, Cursor, a Python script, or anything else you run. The moment you want to do something with the data beyond chatting, you hit a wall.
A health AI that can talk to you but not to your tools is a dead end for anyone who actually works with their data. The question isn't whether Solair is good at answering on-device. It's whether you'll ever want your data to power more than one chat box. A lot of people do, the second they start correlating sleep against HRV or asking an agent to diff two months of workouts.
190 metrics vs 15, side by side
| Solair AI | MetricBridge | |
|---|---|---|
| On-device Q&A | Yes, 15+ metrics | Yes, 190 metrics |
| Provenance cards | No | Yes, every answer shows its numbers |
| Weekly summary | Health digests (beta) | Weekly Brief |
| Agent bridge (MCP) | No | Yes, zero-dependency server, 14 read-only tools |
| Works with your own agents | No | Claude, Cursor, ChatGPT, opencode, more |
| Price | Free | One-time $24.99 |
The developer angle matters more than it looks. Suppose tomorrow you want Cursor to write a script over your sleep data, or opencode to compare two months of HRV. With Solair, you start over: export from Apple Health by hand, parse the XML, build your own pipeline. With MetricBridge, the data is already sitting in a folder as clean JSON, and the MCP server is one config block away.
Want the agent bridge? MetricBridge is the on-device health AI whose MCP server is open source and zero-dependency. A one-time $24.99 purchase covers export, MCP, and on-device chat. No subscription, nothing synced to us.
{
"mcpServers": {
"health-export": {
"command": "npx",
"args": ["-y", "health-export-mcp"],
"env": { "HEALTH_DATA_DIR": "~/Library/Mobile Documents/iCloud~ai~healthexport~app/Documents" }
}
}
}Which one should you use?
If you want the fastest free way to ask on-device questions about your health data, and you're happy to keep those answers inside one app, Solair does the job and costs nothing. It's a legitimately good privacy play.
If you already live in Claude, Cursor, or your own scripts, and want your health data to show up there too, Solair leaves you stranded. MetricBridge is the one that ships both halves: private on-device Q&A with provenance, and an open MCP bridge your agents can actually use. You pay once, and the data belongs to your whole setup instead of a single chat.
The deciding question is one sentence: do you want your health data to stay in a chat app, or do you want it to power everything else you run. If it's the second, the choice is already made.
Ask your Apple Health data anything, then put it to work
On-device answers with provenance, plus an open-source MCP server for every agent you run. Local-first, read-only, no accounts.
Frequently asked questions
Is Solair AI free?
Yes. Solair AI is free with no subscription, no account, and no in-app purchases. It is built by one independent developer and runs on-device by default, analyzing 15+ Apple Health metrics including steps, heart rate, sleep stages, workouts, VO2 max, and HRV.
Does Solair AI let you export Apple Health data to your own AI agents?
No. Solair answers questions about your health data inside its own chat, but it has no MCP server and no health-data export, so you cannot feed that same data to Claude, Cursor, or your own scripts. MetricBridge exports 190 metrics that any MCP client can query through a zero-dependency server.
What does MetricBridge do that Solair AI does not?
MetricBridge covers 190 Apple Health metrics versus Solair's 15+, shows a provenance card with the exact numbers behind each answer, and ships a zero-dependency MCP server with 14 read-only tools so your own agents can query the same local data.
Do both apps keep your Apple Health data on your phone?
Yes. Both answer on-device with no upload of your health history. The difference is what you can do with the data: Solair keeps it inside one chat loop, while MetricBridge also lets you point your own AI agents at the same local export.