Connect Intervals.icu to Claude

ThresholdLink is a remote MCP server that connects your Intervals.icu account to Claude. Once it is connected, Claude can read your training while you chat and add planned workouts, races and notes to your Intervals.icu calendar. There is nothing to install and no API key to copy, and because it is a remote connector it works in Claude on the web, in the desktop app and in the mobile apps.

What you can ask

Ask the way you would ask a coach who has read every file. For example:

• “How’s my fitness trending before the race on the 23rd?” Claude reads your fitness, fatigue and form (CTL and ATL) and your calendar.
• “Why did Tuesday’s intervals feel so hard?” It compares the session’s power and heart rate with earlier ones and with your HRV, resting heart rate and sleep.
• “How much time did I spend in zone 2 over the last four weeks?” It adds up time in zones across your activities.
• “Has my 20-minute power improved since spring?” It reads your power curve. Runners can ask the same of their pace curve.
• “Build me 4×8 min at threshold for Thursday and put it on my calendar.” It sets targets from your zones and adds the planned workout to Intervals.icu, which syncs it to Garmin, Wahoo, COROS and other devices.
• “Plan next week around my long run on Sunday.” It reads your fitness, recent sessions and calendar, proposes a week and, once you confirm, adds all the workouts in one go.
• “Compare today’s 5×6 min with the last ones.” It lines up every repeat of the session side by side: work pace or power, heart rate and drift.

ThresholdLink reads your activities (including intervals, laps, heart rate, pace, power and time in zones), fitness, fatigue and form, wellness (HRV, resting heart rate, sleep and weight), athlete settings and zones, power and pace curves, and your calendar, and it can compare repeats of the same session. The only things it writes are planned workouts, races and notes on your Intervals.icu calendar: it adds workouts one at a time or up to 14 at once, adds races and notes when you ask, and can change or delete the workouts, races and notes it added itself. It never changes or deletes anything else in your calendar or your activities.

ThresholdLink also offers three ready-made prompts: a weekly review, a plan for next week and a session debrief. In a chat, open the + menu, choose Connectors and then ThresholdLink to pick one.

Set it up

You add ThresholdLink to Claude once, as a custom connector:

1. In Claude, open Customize, then Connectors.
2. Choose + Add, then Add custom connector.
3. Enter ThresholdLink as the name and https://thresholdlink.app/mcp as the remote MCP server URL, then choose Continue.
4. Claude shows the sign-in settings it detected. Keep the recommended options and choose Add.
5. When Claude asks you to sign in, follow the steps in the next section.
6. In a chat, open the + menu, choose Connectors and check that ThresholdLink is switched on. Then ask.

On Team and Enterprise plans, an owner first adds the connector under Organization settings → Connectors. Members then find it under Customize → Connectors and choose Connect.

These steps follow Anthropic’s help article Get started with custom connectors using remote MCP as of November 2026. If Claude’s menus have moved since, the article has the current path.

What happens when you sign in

1. ThresholdLink’s consent page. Claude opens a ThresholdLink page that lists what ThresholdLink reads and what it writes. HRV, resting heart rate, sleep and weight are health data, so it asks for your explicit consent with a checkbox.
2. Intervals.icu. You log in to Intervals.icu and approve access for ThresholdLink there. Your Intervals.icu password stays with Intervals.icu.
3. Back in Claude. The connector shows as connected and Claude can use it. At no point is there an API key to copy.

From then on, ThresholdLink keeps only your Intervals.icu athlete ID and an encrypted access token. Training and health data is fetched live when Claude asks for it, held in memory for at most 15 minutes and never written to disk. The privacy policy has the details.

How to disconnect

• Ask Claude. Say “disconnect ThresholdLink”. ThresholdLink revokes its access at Intervals.icu and deletes your athlete ID and all tokens.
• In Intervals.icu. Revoke ThresholdLink’s access in your Intervals.icu settings. ThresholdLink deletes your connection as soon as it learns of the revocation.
• By email. Write to privacy@thresholdlink.app and we delete it for you.

To remove the connector from Claude as well, open Customize → Connectors and choose Remove or the three-dot menu next to ThresholdLink. Removing it in Claude only stops Claude from using it, so disconnect first if you also want your connection deleted on our side. Connections that have not been used for 12 months are deleted anyway.

More

Using ChatGPT? See Connect Intervals.icu to ChatGPT. Questions about data, limits and cost are answered in the FAQ. If something does not work, see Troubleshooting.