Set up garmlink in ChatGPT

Set up garmlink in

garmlink connects to ChatGPT as a developer-mode connector over the Model Context Protocol (MCP). Once it's linked, ChatGPT answers from your real, synced Garmin history — no copy-pasting, no screenshots.

Before you start You need a garmlink account with your Garmin connected (do that on the Connection screen), and a ChatGPT plan where developer mode exists — Plus, Pro, Business, Enterprise or Education on the web. It is not on the free plan and not in the mobile apps; on a Business, Enterprise or Education workspace an admin has to allow it first.

Connect your Garmin account

On the Connection screen, sign in to Garmin Connect with your email and password (used once, never stored) and complete the verification code if asked. Wait for the status to read Connected.

Enable developer mode in ChatGPT

Go to Settings → Security and login → Developer mode and turn it on. This is what lets you add a custom MCP connector.

Interfaces that haven't been updated yet keep the same switch under Settings → Apps & Connectors → Advanced → Developer mode. If it isn't in one place, look in the other — a missing switch is almost always one of the two paths, not a missing feature.

Fill in the “New connector” dialog

Open chatgpt.com/plugins → +. Older interfaces open the same dialog from Settings → Apps & Connectors → Create. The two fields that trip people up are the URL (must end in /mcp) and Authentication (must be OAuth, not “No authentication”).

The “New connector” dialog, field by field — tap to open full-size.

Name — garmlink — just the label shown in ChatGPT.
Description (optional) — anything, e.g. “My Garmin training, sleep & recovery”.
Connection — choose Server URL (not Tunnel).
MCP server URL — it must end in /mcp:https://api.garmlink.ai/mcp
Authentication — select OAuth. Do NOT pick “No authentication” — garmlink returns a 401 challenge to start the OAuth sign-in, so “no auth” fails with “Error creating connector”.
I understand and want to continue — tick it — ChatGPT shows a generic risk notice for any custom MCP server.
Create — press it. ChatGPT then kicks off the OAuth flow (next step).

Icon (optional)

PNG, 256×256, ≤ 10 KB. The garmlink icon carries its own background, so it stays readable whether the assistant's interface is light or dark.

On a light interface

On a dark interface

Download the icon

Once created, the app appears under Drafts in your app settings — that's expected, it stays private to you.

Approve access (OAuth)

ChatGPT sends you to garmlink. Sign in, then on the Authorize access screen press Authorize. ChatGPT returns you and the connector shows as connected. To cut off access, remove the garmlink connector in ChatGPT; disconnecting Garmin stops the sync from Connection screen.

Ask your first question

In a new chat, make sure the garmlink connector is enabled for the conversation, then try:

“Am I ready for my half marathon in 6 weeks?”
“How has my HRV trended versus my sleep this month?”
“Which of my rides had the highest normalized power?”

Troubleshooting

“Error creating connector.” Almost always one of two things: the URL doesn't end in /mcp, or Authentication is set to “No authentication” instead of OAuth. Fix either and press Create again.
No connector / developer-mode option. Developer mode exists on Plus, Pro, Business, Enterprise and Education, on the web only. On the free plan, in the mobile apps, or on a workspace where an admin hasn't allowed it, the option simply isn't there. Claude is the way round it: Claude takes custom connectors on its Free plan (one connector, which is all you need here).
Data looks empty or stale. Check where the sync stands on the Connection screen.
Reconnect needed. If your Garmin session expired, reconnect from the Connection screen.

Using another assistant? See all four setup guides. Curious what garmlink can read? Browse the tools reference.