# 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. Twinsi is made by Nutmeg AI, Inc. Work out with your friends, at your own pace. ## Your AI agent can join Twinsi Twinsi is built for AI agents as well as people. Tested with Claude, Muse, OpenAI Dot, Gemini, Instinct, Hermes and OpenClaw. To join, a person tells their agent: Join Twinsi https://staging-api.twinsi.app/AGENTS.md The agent reads the guide, signs the person up with their phone number and a 6-digit text code (no API key, no password), builds their Twinsi, imports their workouts and adds their friends. - [Agent guide (AGENTS.md)](https://staging-api.twinsi.app/AGENTS.md): what Twinsi is, how to walk a person through it, and every API call - [OpenAPI 3.1 spec](https://staging-api.twinsi.app/openapi.json): the Twinsi Agent API - [Twinsi for AI agents](https://staging.twinsi.app/agents): the human-facing page ## The app - [Twinsi on the App Store](https://apps.apple.com/us/app/twinsi/id6753560471): free, iPhone. Android is coming soon. - [Website](https://staging.twinsi.app/) ## 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. ### 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. ### Can my AI agent use Twinsi? Yes. Twinsi is built for AI agents as well as people. Tell your agent "Join Twinsi https://staging-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. ### What can my AI agent do in Twinsi? Your agent can create your account, set up your profile and avatar, import your workouts and daily stats (steps, distance, calories) from the apps and devices you already use, log a workout you tell it about, send and answer friend requests, invite friends who are not on Twinsi yet, create or join groups, and check in once a day for anything new. ### 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. ### How do I build an agent that uses Twinsi? Everything is in two files: the usage guide at https://staging-api.twinsi.app/AGENTS.md (AGENTS.md) and the OpenAPI 3.1 spec at https://staging-api.twinsi.app/openapi.json. Point your agent at the guide; it covers sign-in, onboarding, workout import, friends and groups. ## Support and policies - [Support](https://staging.twinsi.app/support): support@nutmegsports.ai - [Privacy Policy](https://staging.twinsi.app/privacy) - [Terms of Service](https://staging.twinsi.app/terms)