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

# Fetch API Explorer Data

> Import series from any connected external data provider — central banks, statistics offices and international organizations.

The **Fetch API Explorer Data** step imports series directly from an external data provider, without going through an Alphacast dataset first. It covers the same 30+ connectors documented in [Data providers](/concepts/data-providers) — central banks, national statistics offices, market data sources and international organizations.

## Configuration

| Field         | Description                                                                                                                                     |
| ------------- | ----------------------------------------------------------------------------------------------------------------------------------------------- |
| Provider      | The external provider to pull from. One provider per step.                                                                                      |
| Series        | The series to fetch from that provider. Each entry carries the provider's own series identifier.                                                |
| Output format | **Wide** gives one column per series. **Long** stacks them with `Provider` and `Series` columns alongside the provider's own entity dimensions. |

## Wide vs long

In **long** format the output carries `Date`, `Provider`, `Series`, any entity dimensions the provider returns, and `Value`. This is the better choice when you are fetching many series from one provider and want to filter or group them downstream.

In **wide** format each series becomes its own column, joined on date.

<Note>
  Some providers require an API key. Keys are stored per user, not per pipeline — see [Data providers](/concepts/data-providers) for how to save one, and [Provider tools](/mcp/tools/providers) for managing them through an agent.
</Note>

<Warning>
  The step fails if no provider or no series is configured, if a series returns no data, or if a configured series is missing its identifier.
</Warning>

<Tip>
  To find the right provider and series identifier before building the step, browse the catalog through the [API](/api/providers/list) or ask an agent using the [provider tools](/mcp/tools/providers).
</Tip>

## Next steps

<CardGroup cols={2}>
  <Card title="Data providers" icon="globe" href="/concepts/data-providers">
    The full catalog of connected providers.
  </Card>

  <Card title="Publish to Dataset" icon="upload" href="/steps/publish">
    Turn the fetched series into an auto-updating dataset.
  </Card>
</CardGroup>