## Transformers

URL: https://docs.atlan.com/product/capabilities/build-apps/sdks/application-sdk/references/transformers

> Overview of metadata transformers that convert raw metadata into Atlas-compatible entities for ingestion into Atlan.

daft.DataFrame",
 purpose: "Transforms raw metadata from data sources into Atlas-compatible entities. Must be implemented by all transformer classes. Converts raw metadata DataFrames into properly structured Atlas entities that can be ingested into Atlan.",
 async: false,
 parameters: [
 {
 name: "typename",
 type: "str",
 required: true,
 description: "Type identifier for the metadata (e.g., 'DATABASE', 'SCHEMA', 'TABLE', 'COLUMN')"
 },
 {
 name: "dataframe",
 type: "daft.DataFrame",
 required: true,
 description: "Raw metadata as a daft DataFrame"
 },
 {
 name: "workflow_id",
 type: "str",
 required: true,
 description: "Identifier for the workflow requesting the transformation"
 },
 {
 name: "workflow_run_id",
 type: "str",
 required: true,
 description: "Identifier for the specific workflow run"
 },
 {
 name: "entity_class_definitions",
 type: "Dict[str, Type[Any]] | None",
 required: false,
 description: "Optional mapping of entity types to their class definitions"
 },
 {
 name: "**kwargs",
 type: "Any",
 required: false,
 description: "Additional keyword arguments for specific transformer implementations"
 }
 ],
 returns: {
 type: "daft.DataFrame",
 description: "Transformed metadata as a daft DataFrame with Atlas-compatible structure"
 }
 }
 ]}
/>

## Transformer implementations

The Application SDK provides two concrete implementations of the `TransformerInterface`, each optimized for different transformation approaches. All implementations follow the transformer interface contract, which defines the `transform_metadata` method that converts raw metadata into Atlas-compatible entities.

 Converts metadata into Atlas entities using pyatlan library classes. Uses entity class definitions to create properly structured Atlas entities with relationships and qualified names.

 Transforms metadata using SQL queries defined in YAML templates. Executes SQL transformations on raw dataframes using the daft engine and automatically creates nested structures.

## Common utilities

The transformers module provides utility functions for common operations including text processing, qualified name building, and template path mapping.

See [Common utilities](https://docs.atlan.com/llms/platform/build-apps/common-utilities/llms.txt) for complete reference documentation.

## Usage in workflows

Transformers are typically used in metadata extraction workflows:

```python
from application_sdk.transformers import AtlasTransformer
from application_sdk.activities.metadata_extraction import BaseSQLMetadataExtractionActivities

class MyActivities(BaseSQLMetadataExtractionActivities):
 transformer_class = AtlasTransformer

 def __init__(self):
 super().__init__(transformer_class=AtlasTransformer)
```

The transformer is automatically initialized with:
- `connector_name`: Application name
- `tenant_id`: Tenant identifier
- Additional parameters from workflow configuration

## Entity types

Common entity types supported by transformers:

- `DATABASE`: Database entities
- `SCHEMA`: Schema entities
- `TABLE`: Table entities
- `VIEW`: View entities
- `MATERIALIZED VIEW`: Materialized view entities
- `COLUMN`: Column entities
- `FUNCTION`: Function entities
- `PROCEDURE`: Stored procedure entities
- `TAG_REF`: Tag attachment entities

## See also

- [Common utilities](https://docs.atlan.com/llms/platform/build-apps/common-utilities/llms.txt): Utility functions for text processing, qualified name building, and template path mapping
- [Atlas transformer](https://docs.atlan.com/llms/platform/build-apps/atlas-transformer/llms.txt): Convert metadata into Atlas entities using pyatlan library classes
- [Query-based transformer](https://docs.atlan.com/llms/platform/build-apps/query-based-transformer/llms.txt): Transform metadata using SQL queries defined in YAML templates
- [Application SDK README](https://docs.atlan.com/llms/platform/build-apps/application-sdk/llms.txt): Overview of the Application SDK and its components

_Last updated: 10 August 2026._

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