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

# Introduction

> Unified prediction market API for Polymarket and Kalshi

Synthesis provides a single API to trade on prediction markets across Polymarket and Kalshi. Create wallets, place orders, stream real-time data, and manage positions — all through one integration.

## Base URL

```
https://synthesis.trade
```

## Quick links

<CardGroup cols={2}>
  <Card title="Getting started" icon="rocket" href="/docs/guides/getting-started">
    Create an account, set up a wallet, and place your first order.
  </Card>

  <Card title="Authentication" icon="lock" href="/docs/guides/authentication/project-api-key">
    Learn about project API keys, session tokens, and account API keys.
  </Card>

  <Card title="Real-time data" icon="bolt" href="/docs/guides/websockets/balance">
    Stream live balances, orderbooks, and trades via WebSockets.
  </Card>

  <Card title="API reference" icon="terminal" href="/docs/api-reference">
    Browse all available endpoints across Projects, Markets, Wallets, and more.
  </Card>
</CardGroup>

## Response format

All API responses use a consistent envelope format.

<CodeGroup>
  ```json Success theme={null}
  {
      "success": true,
      "response": {
          "data": "..."
      }
  }
  ```

  ```json Error theme={null}
  {
      "success": false,
      "response": "Error message"
  }
  ```
</CodeGroup>

## Authentication overview

The API uses three authentication methods depending on the type of request.

| Auth Method     | Header                      | Use Case                     | Routes                                  |
| --------------- | --------------------------- | ---------------------------- | --------------------------------------- |
| Project API Key | `X-PROJECT-API-KEY`         | Backend account management   | `/api/v1/project/*`                     |
| Session Token   | `Authorization: Bearer ...` | Frontend user authentication | `/api/v1/account/*`, `/api/v1/wallet/*` |
| Account API Key | `X-API-KEY`                 | Backend user operations      | `/api/v1/account/*`, `/api/v1/wallet/*` |

<Card title="Learn more about authentication" icon="arrow-right" href="/docs/guides/authentication/project-api-key">
  See detailed examples for each authentication method.
</Card>