> Documentation index: https://pmdata.dev/llms.txt. Full docs in one file: https://pmdata.dev/llms-full.txt

# Quick Start

Source: https://pmdata.dev/docs

> Create an API key and download Polymarket or Chainlink historical data.

PMData delivers historical Polymarket and Chainlink data as Parquet files through a simple download API.

## 1. Create an API key

Open the [PMData dashboard](https://pmdata.dev/app) and create an API key.

Send the key in the `api_key` request header. In pandas, pass it through `storage_options` as shown below.

## 2. Choose a dataset

| Dataset | Use it for | File format |
| --- | --- | --- |
| [Polymarket](https://pmdata.dev/docs/historical-data-details/polymarket) | Any Polymarket market recorded from May 1, 2026 | Parquet |
| [Chainlink](https://pmdata.dev/docs/historical-data-details/chainlink) | Chainlink Streams and 30s/60s TWAP | Parquet |

## 3. Download data

### UpDown Markets

```python

series = "btc-5m"  # btc-15m, btc-1h, eth-5m, ...
data_type = "l2"  # trades, onchain_fills
date = "2026/08/08"

url = (
    f"https://api.pmdata.dev/v1/polymarket/{data_type}/"
    f"{date}/{series}.zip"
)

response = requests.get(url, headers={"api_key": "<YOUR_API_KEY>"})
# response.content contains the ZIP file bytes
```

### Any Polymarket market

```python

date_path = "2026/08/08"
market_slug = "will-jd-vance-win-the-2028-us-presidential-election"
data_type = "l2"  # trades, onchain_fills

file_name = f"{market_slug}.parquet"
url = f"https://api.pmdata.dev/v1/polymarket/{data_type}/{date_path}/{file_name}"

df = pd.read_parquet(
    url,
    storage_options={
        "api_key": "<YOUR_API_KEY>",
        "User-Agent": "Mozilla/5.0",
    },
)
print(df.head())
```

Chainlink downloads are available to paid users. See [Chainlink historical data details](https://pmdata.dev/docs/historical-data-details/chainlink) for its URL and supported data types.

## Next steps

- Read the [API Reference](https://pmdata.dev/docs/api-reference) for download endpoints, parameters and responses.
- Read the [Overview](https://pmdata.dev/docs/historical-data-details/overview) under Historical Data Details to choose the correct dataset.
- Open the [Overview](https://pmdata.dev/docs/schemas/overview) under Data Schemas to inspect fields and data types.
- Check [Product Updates](https://pmdata.dev/docs/product-updates) for collection and schema changes.