---
title: Metadata
sidebar_position: 6
description: This guide provides instructions for returning metadata from the provider interface that gets included in the `extra` attribute of the OBBject response.
keywords:
- OpenBB Platform
- metadata
- provider
- results metadata
- fetcher
- AnnotatedResult
- annotations
- develop
---

import HeadTitle from '@site/src/components/General/HeadTitle.tsx';

<HeadTitle title="Metadata - Developer Guides | OpenBB Platform Docs" />

## Overview

When data needs to be included in the output, but should not be included in the serialized results,
it can sent to the `extra` attribute of the [OBBject](obbject) command response by using the `AnnotatedResult` class.

A simple modification to the `transform_data` static method, in the provider's Fetcher class, is all that is required. The steps are outlined below.

## How-To Add Metadata

### Import Statement

- Add an additional import to the provider's model file.

```python
from openbb_core.provider.abstract.annotated_result import AnnotatedResult
```

### Transform Data

- Wrap the output type in the `transform_data` static method with this imported class.

```python
    @staticmethod
    def transform_data(
        query: FredSeriesQueryParams,
        data: List[Dict[str, Any]],
        **kwargs: Any,
    ) -> AnnotatedResult[List[FredSeriesData]]:
        """Transform data."""
```
- Return the `AnnotatedResult` class by initializing it with a dictionary of metadata and the validated data model.

Instead of something like this:

```python
return [FredSeriesData.model_validate(d) for d in data]
```

It will be like this:

```python
return AnnotatedResult(
    result=[FredSeriesData.model_validate(r) for r in records],
    metadata=metadata,
)
```

:::important
`metadata` should be a valid Python dictionary with keys and values that are JSON-serializable.
:::

The example above is a snippet from the [`FredSeries`](/platform/data_models/FredSeries) data model.