Claude Desktop and Marrow Health

Cloud MCPLocal MCPServer MCP

Two ways into Claude Desktop: the same connector as the Claude app, or Marrow's free desktop extension, one file you double-click, pointed at your phone or your own server.

Open in Marrow Download on theApp Store

Open in Marrow works on an iPhone with Marrow 1.4.2 or later.

Which way?

Cloud MCP if you want answers any time with nothing to run. Part of Marrow Pro.
Local MCP if the computer running it shares your phone's Wi-Fi or tailnet. Free, and it answers while Marrow is open.
Server MCP if you keep a small server running. Free, and it answers any time.

Cloud MCP: Connector Local MCP Server MCP

Cloud MCP (Connector) Pro

A private copy of your data on Marrow's server. Your AI reads it any time, phone asleep, and every sign-in is approved on your phone. You need: Any Claude plan, Free included.

In Marrow, open Export and tap Claude Desktop. Pick Cloud MCP.
Turn Cloud MCP on (Marrow Pro) and add Claude Desktop to Your connections. Marrow shows your link.
Claude Desktop: Settings, Connectors, Add custom connector, paste your link.
```
https://connect.marrowhealthapp.com/t/<your-id>/mcp
```
Click Connect. Type the code the page shows into Marrow and approve.
Ask: How am I doing today?

Placeholder shown: Marrow fills in your own link.

Local MCP (Desktop extension) Free

A server on your iPhone. It answers while Marrow is open, to apps on the same Wi-Fi or tailnet. Nothing leaves your network. You need: Any plan.

In Marrow, open Export and tap Claude Desktop. Pick Local MCP.
Turn Local MCP on and add Claude Desktop to Your connections. Marrow shows the address and a token made for this connection.
Download marrow.mcpb from the releases page and open it.
Paste the address and token below when it asks.
```
http://<phone-ip>:21212/mcp
Token: <token>
```
Ask: How am I doing today?

Placeholders shown: Marrow fills in your phone's address and the token.

Download marrow.mcpb

Server MCP (Desktop extension) Free

Marrow's open-source server on a computer you keep on (a Pi, a NAS, an old laptop). The phone keeps it current and it answers any time. You need: Any plan.

Run Marrow's server on a computer you keep on and pair it with the app (how).
In Marrow, open Export, tap Claude Desktop and pick Server MCP. Add it to Your connections. Marrow shows the server's address. The token is the mcp token your server printed when it started.
Download marrow.mcpb from the releases page and open it.
Paste the address and token below when it asks.
```
http://<server-ip>:8800/mcp
Token: <token>
```
Ask: How am I doing today?

Placeholders shown: Marrow fills in your server's address. The token is the one your server printed.

Download marrow.mcpb

What it can do

Read. A daily brief scored against your own normal, your baselines, what changed this week, any metric day by day, workouts, lifts set by set, sleep stages and your food diary.
Log. Your AI logs meals, water, weight, workouts, sleep, symptoms and mood when you ask, after you turn on Allow AI write for that way in Marrow. Every entry can be undone.

Try asking

How am I doing today?
What changed in my sleep this week compared with my normal?
Which of my lifts went up this month?
Log a turkey sandwich and an apple for lunch.

If it does not work

In Claude Desktop

The connector says Couldn't reach the MCP server. The connector runs from Anthropic's servers and takes the Cloud MCP link only. For your phone or your own server, use the desktop extension.
Marrow answered 401. The extension's message when the token is wrong or the connection is off in Marrow. Open the extension in Settings, Extensions and enter the address and token again. Each Local MCP connection has its own token.
Could not reach the address. The extension's message when the computer cannot reach the phone or server. Keep Marrow open on the same Wi-Fi, then test the address with the curl line in the Local MCP guide.
The tools do not show up. Restart Claude Desktop. If they still do not, read the logs: ~/Library/Logs/Claude on a Mac and %APPDATA%\Claude\logs on Windows. mcp.log has the connection errors.
Opening marrow.mcpb does nothing. In Settings, Extensions, open Advanced settings and use Install Extension, or drag the file onto that page. If Extensions is missing from Settings, extensions are turned off for your account.

Cloud MCP checks

The sign-in waits in Marrow. The sign-in page shows a 6-character code. Open Marrow, go to Export, type the code and tap Approve. A request expires after ten minutes and three wrong codes deny it. If that happens, start again from your AI.
The page says the link did not match a Marrow. In Marrow, open your AI under Connections, tap Copy your link and paste the whole link.
It worked, then stopped. When Cloud MCP is off, or Marrow Pro has ended, the copy is paused. Switching Cloud MCP off also signs every AI out. Turn it back on, switch this connection on in Your connections and sign in again from your AI.
Approve stops at the limit. Each AI is one connection. Free keeps 1 connection on at a time. Marrow Pro keeps up to 10: AIs, servers and automations together. Turn one off in Your connections, then approve again.
It reads but cannot log. Turn on Allow AI write for Cloud MCP in Marrow. An entry reaches the phone within seconds when notifications are allowed for Marrow, or the next time you open the app.

Local MCP checks

Keep Marrow open. The phone's server answers only while Marrow is open in front. When you switch apps or lock the phone, iOS soon pauses it. Open Marrow again and it answers again.
Same Wi-Fi or tailnet. The computer must be on the phone's Wi-Fi or tailnet, never cellular. Guest Wi-Fi often stops devices reaching each other. Over Tailscale, use the phone's tailnet address (it starts with 100.) in place of its Wi-Fi address, and check the Wi-Fi address again if your router hands out a new one.
401 Unauthorized. The token is wrong, or this connection is off in Marrow. Each connection has its own token, and turning one off locks that app out. Switch it on in Your connections, or copy the token again.
Test from the computer. The curl line in the Local MCP guide shows whether the phone answers, and with which error.

Server MCP checks

Reach the server first. From the computer running your AI, open http://<server-ip>:8800/health. It answers without a token. If it does not, the server is not running or the address is wrong. Then try the curl test on the Server MCP page.
401 from the server. Agents use the mcp token the server printed when it started. It is also in the .mcp-token file in the server's data folder. The phone's pairing token does not work for agents.
Old data, or Not delivering in Marrow. The phone cannot reach the server to push. Check the server is running and that its address in Marrow still works from the phone. For a server on your home network, Marrow needs Local Network access: Settings, Privacy and Security, Local Network.
It reads but cannot log. Turn on Allow AI write for this server in Export, Your connections. Entries wait on the server and land when Marrow next opens or wakes.

More fixes in the guides: Cloud MCP, Local MCP, Server MCP.

More help

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