Connecting an AI Assistant with an API Key

Not every AI assistant can sign in to the FitnessSyncer MCP Server for you. Many offer only a server address and a place to put a token, and some read their whole configuration out of a file on disk. For those, FitnessSyncer issues an API Key, which is a single long-lived token that stands in for the whole sign-in.

This is how Mistral Vibe connects, and it is also the answer for a self-hosted assistant, a command-line client, an agent framework, or a ChatGPT that offers you a header rather than an OAuth screen. Claude, ChatGPT, Perplexity and Home Assistant each have a sign-in of their own, so prefer their own instructions where they apply.

Before you start

• A FitnessSyncer account with your sources connected. The MCP Server is included with every account, so there is nothing extra to buy; see Getting Started if you are new. A free account reaches back over less history here, exactly as it does everywhere else on the site.
• An assistant that can send an Authorization header, or that calls the same thing a Bearer Token or an API token. If yours can sign in with OAuth instead, that is the better route, because you choose the permissions each time rather than once.

Step 1: Create your API Key on FitnessSyncer

1. Go to the Developer Accounts page.
2. At the bottom of the page, select “MCP: API Key” from the list and click “Create”.
3. FitnessSyncer asks which permissions this key should carry. Select only what you want the assistant to do; for answering questions, the read permissions are enough, and nothing you leave unchecked can be used later without creating a new key.
4. Select Create API Key, and note the API Key on the next page. It is only displayed this once; if you lose it, you can regenerate it, but you will then need to enter it in your assistant again.

  Step 2: Mistral Vibe

With your API Key in hand:

1. From the left menu, select Context and then Connectors.
2. Select Add Connector in the upper right corner of the screen.
3. Select Custom MCP Connector.
4. Enter FitnessSyncer for the Name
5. Enter https://www.fitnesssyncer.com/services/mcp for the Server
6. Select API Token Authentication and paste your API Key into the Bearer Token.

Step 2: Any other assistant with a settings screen

The fields are named differently from one assistant to the next, but there are only ever three:

1. Enter FitnessSyncer for the Name
2. Enter https://www.fitnesssyncer.com/services/mcp for the Server, which some assistants call the Remote MCP server URL
3. Enter your API Key into the Bearer Token field. If the assistant asks for a header instead, the header name is Authorization and its value is the word Bearer, a space, and your API Key.

If the assistant also asks you to choose a transport, select Streamable HTTP. FitnessSyncer does not offer the older SSE transport.

Step 2: An assistant configured from a file

Many command-line and desktop clients read their servers out of a JSON file. The shape varies, so match your own assistant’s documentation, but it usually looks like this:

{
 "mcpServers": {
   "FitnessSyncer": {
     "transport": "http",
     "url": "https://www.fitnesssyncer.com/services/mcp",
     "headers": {
       "Authorization": "Bearer YOUR_TOKEN_HERE"
     }
   }
 }
}

Replace YOUR_TOKEN_HERE with your API Key, keeping the word Bearer and the space in front of it.

Try it

Start a new chat and paste any of these to check that everything is working:

• List all the apps and devices FitnessSyncer is currently connected to for my account and show when they last synced.
• How did I sleep this week compared to last week?
• What has my resting heart rate done over the last month?

There are many more ideas on the MCP Server page.