> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ascendapi.com/llms.txt
> Use this file to discover all available pages before exploring further.

# API Reference

> Complete reference for all AscendAPI endpoints

Every endpoint requires a **RapidAPI key** for authentication. If you have not set one up yet, head to the [Quickstart](/quickstart) first.

***

## Authentication

All AscendAPI endpoints are authenticated via your RapidAPI key. Pass it as a header with every request.

```bash theme={"system"}
X-RapidAPI-Key: YOUR_RAPIDAPI_KEY
```

<Warning>
  Never expose your RapidAPI key in client-side code or public repositories. Always make API calls from your backend or a secure server environment.
</Warning>

***

## Explore with Scalar

Prefer an interactive API explorer? Each product has a dedicated Scalar docs environment where you can browse endpoints, inspect response schemas, and make live requests directly in the browser.

<Note>
  Scalar docs let you make live API calls directly in the browser. You will still need your RapidAPI key to authenticate requests there.
</Note>

<CardGroup cols={1}>
  <Card title="ExerciseDB V1" icon="database" href="https://v1.exercisedb.dev">
    Interactive Scalar docs for the V1 exercise dataset. 2000+ exercises with GIF animations and structured instructions.
  </Card>

  <Card title="ExerciseDB V2" icon="database" href="https://v2.exercisedb.dev">
    Interactive Scalar docs for the V2 exercise dataset. 11,000+ exercises with images, videos, and multilingual metadata.
  </Card>

  <Card title="Muscle Visualizer" icon="biceps-flexed" href="https://muscle-visualizer.exercisedb.dev/docs">
    Interactive Scalar docs for the Muscle Visualizer API. Dynamic muscle diagrams and heatmap visualizations.
  </Card>
</CardGroup>

***

<Card title="Quickstart Guide" icon="zap" href="/quickstart">
  New here? The Quickstart walks you through getting your key and making your first API call in under 5 minutes.
</Card>