Work out with your friends, at your own pace.
Fitness companions that level up when you work out, friends who train alongside you, and no pressure to keep a streak alive.
@emily
@robbiekeyz
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@derikTwinsi for AI agents
Your AI agent can join Twinsi for you.
Twinsi is one of the first fitness apps built for AI agents. Paste one line into a chat with Claude, Muse, OpenAI Dot, Gemini, Instinct, Hermes and OpenClaw, and your agent does the rest.
Join Twinsi https://api.twinsi.app/AGENTS.mdSigns you up
Your agent asks for your mobile number and the code we text you. No app, no password, no API key.
Brings in your workouts
It imports your workouts and daily stats from Apple Health, Strava, Garmin and more, or logs the one you just told it about.
Keeps up with your friends
It adds friends, invites the ones not on Twinsi yet, sets up groups, and checks in once a day for anything new.
Challenge your friends
Join a weekly challenge with your friends and see whose Twinsi puts in the work.
Progress you can see
Your Twinsi levels up, dresses up, and shows up differently as your fitness journey unfolds.
Fits into your life
Twinsi plugs into your existing fitness apps and turns your workouts into shareable cards.
Apple Health
and more
Questions
What is Twinsi?
Twinsi is a social, low-pressure fitness app you use with your friends. Each person gets a Twinsi: an avatar built from a selfie that levels up, dresses up and changes as they work out. Twinsi brings in workouts from Apple Health, Strava, Peloton, Garmin and more, turns them into shareable cards, and lets friends see what each other are training. There are two ways to use it: the free iPhone app, or through your AI agent. Twinsi is one of the first fitness apps your AI agent (Claude, Muse, OpenAI Dot, Gemini, Instinct, Hermes and OpenClaw) can join for you: paste one line into a chat and your agent signs you up, imports your workouts and adds your friends.
Can my AI agent use Twinsi?
Yes. Twinsi is built for AI agents as well as people. Tell your agent "Join Twinsi https://api.twinsi.app/AGENTS.md" and it reads the guide, signs you up with your phone number and a text code, builds your Twinsi, imports your workouts and adds your friends, all inside the chat. You never install an app.
Which AI agents work with Twinsi?
Twinsi has been tested with Claude, Muse, OpenAI Dot, Gemini, Instinct, Hermes and OpenClaw. Any agent that can read a web page and make HTTP requests can follow the same guide.
Is Twinsi free?
Yes. The Twinsi app is free to download on the App Store, and joining through your AI agent is free too.
Is Twinsi on Android?
The Twinsi app is on iPhone today, and an Android app is coming soon. Android users can already join through their AI agent, which works from any device.
What apps and devices does Twinsi work with?
Twinsi brings in workouts from Apple Health, Strava, Peloton, Garmin and more, and turns them into shareable cards. If you join through your AI agent, it imports workouts from the apps and devices it can connect to, or logs the ones you tell it about.
Do I have to keep a streak?
No. Twinsi is low-pressure on purpose: there is no streak to keep alive and nobody is judged on how much or how little they move. You work out with your friends, at your own pace.
How is Twinsi different from Strava or other fitness apps?
Most fitness apps are about tracking and competing. Twinsi is about doing it with friends: your progress shows up on an avatar that looks like you, friends join weekly challenges together, and there is no pressure to keep a streak. Twinsi also works alongside Strava rather than replacing it, and it is one of the few fitness apps your AI agent can join and use for you.
Does my agent need an API key to use Twinsi?
No. There is no API key and no password. Your agent asks for your mobile number, you read back the 6-digit code Twinsi texts you, and that is the whole sign-up.