How to Include DCAT 3 Compliant Distribution Metadata in the Catalog?

[albert-lopez]

Currently, the EDC Distribution class (in the catalog SPI) only supports two properties:

• format (the protocol/technology type, e.g., "HttpData")
• dataService (the access endpoint reference)

However, according to the W3C DCAT 3 specification (https://www.w3.org/TR/vocab-dcat-3/#Class:Distribution), a dcat:Distribution should support additional metadata properties such as:

• dcat:byteSize — The size of the distribution in bytes
• dcat:checksum — A checksum value to verify data integrity
• dcat:mediaType — IANA media type
• Other DCAT-compliant properties

Is there a recommended approach within the EDC ecosystem for including DCAT-compliant metadata (byteSize, checksum, etc.) in distributions?

Thanks in advance

[ndr-brt]

EDC is not DCAT3 fully compliant, but it's DSP v2025-1 compliant, I recommend you to check out the specification:
https://eclipse-dataspace-protocol-base.github.io/DataspaceProtocol/2025-1-err1/#ack-catalog

[albert-lopez]

Thank you for the clarification and the pointer to the DSP v2025-1 specification. It makes perfect sense that EDC aligns with the DSP standard.

However, our specific use case requires us to expose some of these DCAT3 metadata fields (such as byteSize or checksum) to our downstream consumers.

What would be the recommended approach to inject or support these custom properties within the EDC ecosystem? Is it possible to achieve this through a custom extension (for example, by plugging into the JSON-LD transformers), or is the Distribution schema strictly locked in the core DSP modules?

If an extension is the right path, could you point me to the relevant SPIs or core components where I should start looking?

Thanks

[ndr-brt]

you can implement your own DistributionResolver service and register it on the runtime through extension