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Philip D'Souza
Philip D'Souza

Posted on Originally published at healthexport.dev

The on-device health AI niche has a dozen apps. None ships an agent bridge.

#agents #ai #ios #mcp

A dozen-plus iPhone health apps now answer questions about your Apple Health data on the device, with no cloud round trip. As of October 2026, none of them ships an agent bridge: no bundled MCP server, no config block you can paste into Claude Code or Cursor, no connection page naming the agents it supports.

On-device is the claim everyone makes. Agent access is the one almost nobody has built, and it decides whether your health data ever reaches the tools you actually work in.

Two claims, constantly confused

"On-device" describes where an answer is computed. "Agent-connectable" describes where the data can go afterwards. If the app can tell you something but cannot tell your agent anything, you are reading a summary, not a bridge.

Why the second half gets skipped

An agent bridge is a data contract, and the contract is the hard part. A server has to answer which metrics exist, in what unit, over what range; how fresh the file is; and what HRV means when the export carries a device-specific spelling. There is a business reason too: a bridge makes the app a component, and screen time is what the charts reward.

The five-minute test

  1. Open the app's App Store listing and search the text for MCP, Model Context Protocol, and any agent you use.
  2. Find the developer's docs and look for a config block, not a promise: 
{
  "mcpServers": {
    "health": {
      "command": "npx",
      "args": ["-y", "health-export-mcp"]
    }
  }
}
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  1. Search the developer's site for a connection page that names the clients it supports. A page that lists Claude Code, Cursor and opencode is a bridge. "AI integration coming" is not.
  2. Ask one question: could I paste this config and get a real number back, right now, with no hosted account?

The tell: a bridge always documents its tool names. If the docs never name a tool, the agent was never the customer.

What we built

MetricBridge answers on-device with a provenance card on every answer, and also feeds a zero-dependency MCP server so the same numbers reach your own agent. The server ended up as 16 tools and 22 prompts, including get_mcp_status, get_freshness, list_metrics, get_health_metrics, get_trends, compare_periods, get_workouts, get_sleep_sessions, correlate_metrics and resolve_metric. One $24.99 unlock, no account, no subscription, and no server of ours in the path.

Full post, including the app sweep and the method: https://dub.sh/kthXU3E

MetricBridge describes and computes from your own Apple Health data. It is a wellness tool, not a medical device, and it does not diagnose, treat or monitor any condition.

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