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

# PolymarketData API

> Historical Polymarket prices, metrics, and L2 order books for research and backtesting.

PolymarketData stores complete historical market state: minute-level prices, liquidity metrics, and L2 book snapshots. Use it when the public Polymarket API is not enough — that API only returns live state.

Base URL: `https://api.polymarketdata.co`

<Info>
  Every `/v1` endpoint requires an API key in the `X-API-Key` header. Create one in the [dashboard](https://app.polymarketdata.co/register).
</Info>

## What you can query

<Columns cols={2}>
  <Card title="Discovery" icon="search" href="/api-reference/overview">
    Find series, events, markets, and tags. Use the returned market ID or slug on history endpoints.
  </Card>

  <Card title="Prices" icon="chart-line" href="/quickstart">
    Token probabilities from 0.0 to 1.0, aggregated to `1m`, `10m`, `1h`, `6h`, or `1d`.
  </Card>

  <Card title="Metrics" icon="activity" href="/quickstart">
    Volume, liquidity, and spread time series for a market.
  </Card>

  <Card title="Order books" icon="layers" href="/quickstart">
    Historical L2 snapshots as `[price, size]` bid and ask levels.
  </Card>
</Columns>

## Typical workflow

<Steps>
  <Step title="Create an API key">
    Sign in at [app.polymarketdata.co](https://app.polymarketdata.co) and create a key. Send it as `X-API-Key` on every request.
  </Step>

  <Step title="Discover a market">
    Call `GET /v1/markets` (or series and events first). Save the market `id` or `slug`.
  </Step>

  <Step title="Pull history">
    Query `/v1/markets/{id_or_slug}/prices`, `/metrics`, or `/books` with `start_ts`, `end_ts`, and `resolution`.
  </Step>
</Steps>

## Choose your client

<Columns cols={2}>
  <Card title="Quickstart" icon="rocket" href="/quickstart">
    First authenticated request in the Python SDK or raw REST.
  </Card>

  <Card title="Python SDK" icon="code" href="/sdks/python">
    `pip install polymarketdata-sdk` with typed methods and auto-pagination.
  </Card>
</Columns>

<Note>
  Standard coverage starts in August 2025. Earlier history is available on enterprise plans. Plan limits also control resolution, lookback window, and requests per minute — check `GET /v1/usage` if a history call returns `403`.
</Note>