> For the complete documentation index, see [llms.txt](https://docs.pentaho.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.pentaho.com/pdia-data-integration/9.3-data-integration/pdi-transformation-steps-reference-overview/write-metadata.md).

# Write Metadata

You can use the Write Metadata step to add new metadata to any existing metadata in the Pentaho Data Catalog that is already associated with specific data resources. You can add a description and tags to the data resource. You can also add metadata for any new data resources that your transformation may be adding to Data Catalog.

The Write Metadata step includes options to identify, locate, and append the metadata associated with existing Resource IDs in the Data Catalog.

For more information about accessing Pentaho Data Catalog in PDI, see [PDI and Data Catalog](/pdia-data-integration/9.3-data-integration/advanced-topics-pentaho-data-integration-overview/pdi-and-lumada-data-catalog-ldc.md).

**Note:** This step is supported on the PDI engine but not on the Spark engine. Only CSV text file and Parquet data formats are currently supported. You must have role permissions in Data Catalog to read the data resources.


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