Derny

Créez, modifiez et organisez des entraînements structurés pour votre vélo d’intérieur, tapis de course ou vélo elliptique en discutant avec Claude ou ChatGPT. Les entraînements se synchronisent avec l’application Derny (iOS et Android), qui les exécute sur l’appareil et peut les adapter à votre fréquence cardiaque. Connexion OAuth avec un compte Derny.

Voir sur derny.app

Serveur MCP hébergé

npx add-mcp 'https://mcp.derny.app/mcp'

S’installe dans Claude Code, Codex, Cursor et plus

Documentation

A training app that listens to your heart rate.

Derny connects over Bluetooth to your machine and a heart-rate monitor. During a workout it sets the effort for you, the watts on a smart trainer or the belt speed on a treadmill, and changes it as your heart rate responds. Writing workouts with AI is one part of it. You can also use Derny without any AI at all.

Your machine

Trainers, treadmills, ellipticals

Works with FTMS smart trainers and a growing list of treadmills and ellipticals. Trainers · Treadmills · Ellipticals

Heart-rate rules

Workouts that react

A workout can include rules like “if my heart rate stays above 165 for 10 seconds, drop the power by 5 watts.” Derny applies them as you go.

Ready-made

Adaptive workouts built in

Zone 2, threshold and VO2 max sessions that set the effort from your heart rate. See the workouts →

Where AI fits

Your AI writes, Derny runs

Claude or ChatGPT builds the workout in your library. You do the workout in the Derny app, which controls your machine.

Talk about the session, not the file format.

“Make me a 60-minute sweet-spot ride that backs off when my heart rate climbs above 165.”

“Build a 40-minute treadmill run: easy warm-up, then four hard intervals with easy jogs between them.”

“Take my Tuesday intervals and make every recovery a minute longer.”

Your AI can create, list, read, edit and delete the workouts in your Derny library. It can’t see your recorded rides, and it can’t control your trainer or treadmill. You ride the workout in the Derny app like any other.

Connect once, in about a minute.

You need a Derny account (sign in from the Derny app, since your workouts sync to it) and a paid Claude or ChatGPT plan. The connector address is the same in both:

https://mcp.derny.app/mcp

In Claude

  1. Open Customize → Connectors.
  2. Click Add (top right), then Add custom connector.
  3. Name it Derny, paste the URL above, and click Continue.
  4. Under OAuth client, choose Register automatically, then click Add.
  5. Click Connect, sign in to Derny, and approve the connection.
  6. In a chat, turn Derny on from the connectors menu and ask for a workout.

In ChatGPT

  1. Open Plugins in the sidebar, then click Add and Add custom MCP server.
  2. Name it Derny and paste the URL above. Keep Authentication on OAuth.
  3. Tick I understand and want to continue, then click Create as a plugin.
  4. Sign in to Derny when prompted, and approve the connection.
  5. In a chat, type @Derny and ask for a workout.

If ChatGPT says Derny’s tools aren’t available right after you add it, open the plugin’s settings and click Refresh tools.

Once Derny is listed in Claude’s and ChatGPT’s directories, you can also find it there and connect with one click instead of pasting the URL. The menu names above can shift as those apps change; the URL stays the same. The URL is also in the Derny app under Settings → Connected Apps. Whichever you use, the new workout shows up in your Derny library.

Six tools: two read, four change things.

  • List workouts (read). Shows the workouts in your library.
  • Get workout (read). Opens one workout so your AI can read its sections and rules.
  • Create workout (changes your library). Adds a new workout.
  • Update workout (changes your library). Edits a workout you already have.
  • Delete workout (changes your library). Removes a workout.
  • Send feedback (sends us a message). Passes a note about Derny or the connector to the developer.

To try every tool: ask for a workout, ask for your list, ask to see one, ask to change it, send a bit of feedback, then ask to delete it. Your AI should ask before it edits or deletes anything.

You stay in charge of what it can touch.

The connection uses OAuth: you approve it on a Derny sign-in screen, and your AI never sees your password. Every connected app is listed in Settings → Connected Apps. Disconnecting one revokes its access immediately.

AI questions

What is Derny?

Derny is an indoor training app for iPhone and Android. It connects to a smart trainer, treadmill or elliptical and a heart-rate monitor, and adjusts the workout from your heart rate as you go. It is free while in beta.

Can ChatGPT or Claude create workouts for my smart trainer?

Yes, through Derny. Add Derny as a custom connector in Claude or ChatGPT using https://mcp.derny.app/mcp, sign in to approve it, then ask for a workout. It appears in your Derny library, ready to ride on a smart trainer, treadmill or elliptical.

What can the AI see in my Derny account?

Only your workouts. It can create, list, read, edit and delete them. It can’t see your recorded rides and can’t control your machine.

Do I need a paid AI plan?

Custom connectors need a paid plan: Claude Pro, Max, Team or Enterprise, or a paid ChatGPT plan. Derny itself is free while in beta, and will be a one-time purchase after launch.

How do I disconnect my AI from Derny?

Open Settings → Connected Apps in Derny and disconnect it. Its access is revoked immediately.

Stuck? Email us.

Write to [email protected] and a person will reply. Read how we handle your data in the privacy policy and the rules for using Derny in the terms of service.

Free while in beta, on iPhone and Android.

When Derny launches, it will be a one-time purchase, not a subscription.

The beta is live on iPhone through TestFlight and on Android through Google Play. Your invite arrives by email.