Questions and answers
What is ThresholdLink?
ThresholdLink is a remote MCP server that connects your Intervals.icu account to Claude and ChatGPT. Your assistant can then read your activities, fitness, wellness, zones and calendar while you chat, compare repeats of the same session, and add planned workouts (one at a time or a whole week at once), races and notes to your Intervals.icu calendar. MCP, the Model Context Protocol, is the open standard both assistants use for connectors.
Can I use it today?
Yes. ThresholdLink is open to everyone with an Intervals.icu account, and it is free. The setup guides for Claude and ChatGPT show how to connect it.
Is it safe? What do you store?
We store only your Intervals.icu athlete ID and an encrypted access token, plus the tokens your assistant uses to call ThresholdLink. Your training and health data is fetched live from Intervals.icu when your assistant asks for it, held in memory for at most 15 minutes and never written to disk or a database.
Server logs contain no request or response content and are deleted after 14 days. There are no analytics, tracking or ads. ThresholdLink runs on a server at Hetzner in Germany, behind Cloudflare. The privacy policy has the full details.
Why not just use an Intervals.icu API key?
With an API key you copy a long-lived secret for your whole Intervals.icu account into a config file or tool, and keeping it safe is up to you. ThresholdLink uses Intervals.icu’s own sign-in instead: you approve access on Intervals.icu, there is no key to copy, and you can revoke access in your Intervals.icu settings at any time.
How is it different from running an open-source Intervals.icu MCP server myself?
Open-source Intervals.icu MCP servers are a good choice if you like running your own tools: you usually install one on your computer, give it your API key and connect it to a desktop app. ThresholdLink is the same idea as a hosted service. There is nothing to install and no API key, and because it is a remote connector it also works in Claude in the browser and in Claude’s mobile apps, and in ChatGPT, which needs a server it can reach over the internet.
Does it work with Garmin, Zwift, COROS, Wahoo and Strava?
ThresholdLink works with the data in your Intervals.icu account, wherever it came from: Garmin, Zwift, Wahoo, COROS, file uploads and more. When data was recorded on a Garmin device, your assistant credits Garmin, as Garmin requires.
Strava is the exception. Strava’s API terms do not let Intervals.icu pass activities it imported from Strava on to other apps, so those activities are not available to ThresholdLink. Connect your device or platform to Intervals.icu directly to get the full picture.
Which Claude and ChatGPT plans can use it?
ThresholdLink itself is free, but you need your own Claude or ChatGPT account. Anthropic and OpenAI decide which of their plans can add custom MCP connectors, and both have changed this over time. Anthropic’s help article on custom connectors lists the current Claude plans. For ChatGPT it depends on your plan and workspace settings.
Is there a limit to how much I can ask?
Intervals.icu allows apps like ThresholdLink 100 API requests per user per day. To make them go further, ThresholdLink answers identical requests made within 15 minutes from memory, and asks your assistant to prefer one well-scoped request over many small ones.
Can it change or delete things in my Intervals.icu account?
It adds planned workouts to your Intervals.icu calendar, one at a time or up to 14 at once, and Intervals.icu syncs them to Garmin, Wahoo, COROS and other devices like any other planned workout. It can also add races and notes. It can change or delete only the workouts, races and notes it added itself, and never changes or deletes anything else in your calendar or your activities. Your activities, wellness data and settings are only read.
How do I disconnect and delete my data?
Ask your assistant to disconnect ThresholdLink, revoke its access in your Intervals.icu settings, or email privacy@thresholdlink.app. Disconnecting revokes ThresholdLink’s access at Intervals.icu and deletes your athlete ID and all tokens. If you revoke access in Intervals.icu instead, ThresholdLink deletes them as soon as it learns of the revocation. Connections that have not been used for 12 months are deleted automatically.
Your training data itself stays in Intervals.icu, where you can view, change or delete it.
Is it free? How is it funded?
Yes, ThresholdLink is free, with no paid plans and no ads, and your data is never for sale. It runs on donations: if it earns a place in your training, you can support it on Ko-fi.
Who makes it? Is it affiliated with Intervals.icu, Anthropic or OpenAI?
ThresholdLink is made by Kaspar Birk in Denmark. It is independent and not affiliated with Intervals.icu, Anthropic or OpenAI. Questions or ideas: hello@thresholdlink.app.
How do I report a security issue?
Email hello@thresholdlink.app with what you found and how to reproduce it. The details are in our security.txt file.
Sign-in fails or keeps looping. What should I do?
Remove the ThresholdLink connector in your assistant and add it again to start a fresh sign-in. Check that you are logged in to the right Intervals.icu account, because ThresholdLink connects to the account you approve. On ThresholdLink’s consent page, tick the consent checkbox before you choose Continue to Intervals.icu. A sign-in must be finished within 10 minutes; after that, start again from your assistant.
What does “daily limit reached” mean?
Intervals.icu allows ThresholdLink 100 requests per user per day, and today’s have been used. Try again tomorrow. Identical requests repeated within 15 minutes are answered from memory and do not use up more of the limit, and asking for one well-scoped thing instead of many small ones makes the requests go further.
Why are some of my activities missing?
Activities that Intervals.icu imported from Strava are not available to ThresholdLink; the answer to “Does it work with Garmin, Zwift, COROS, Wahoo and Strava?” explains why. Anything else missing is not in your Intervals.icu account yet, so check it there first.
Why does it say an entry was “not created by ThresholdLink”?
ThresholdLink can change or delete only the workouts, races and notes it added itself. Entries you added in Intervals.icu, entries from other apps and entries it added before it started marking them are refused. Change or delete those in Intervals.icu.
New features are not showing after an update. What should I do?
Your assistant may keep the list of tools it saw when it connected. Remove the connector and add it again, or start a new chat. In ChatGPT, open the connector in settings and refresh it.
What does “result too large” mean?
A request, such as a long stretch of activities, returned more than ThresholdLink passes on at once. Ask for a shorter date range or fewer items, or split the question into parts.
Still stuck?
Email hello@thresholdlink.app with what you asked and what happened, and we will help.