Add bidirectional OpenMetadata semantic model converter (converters/openmetadata)

[daniyarndh]

OpenMetadata has emerged as a widely adopted, enterprise-grade unified metadata catalog. It supports rich business glossaries, metrics definitions, and lineage tracking. However, there is currently no standardized way to serialize these cataloged assets into a vendor-neutral, developer-friendly, and version-controlled format that BI engines and AI agents can consume.

By building a bidirectional converter, we bridge OpenMetadata's central governance platform with Apache Ossie's declarative semantic standard, turning OpenMetadata into a first-class participant in the Ossie ecosystem.

Proposed Design & Mapping

The converter will be written in Python, matching the structure of existing converters like converters/dbt and converters/databricks.
Attributes specific to OpenMetadata that are not representable in the core Ossie specification (e.g., column-level tags, owners, tiers, and domain classifications) will be preserved in a custom_extensions block using the OPENMETADATA vendor namespace:

custom_extensions:
  - vendor_name: OPENMETADATA
    data:
      owner: "finance_team"
      tier: "Tier1"
      tags: ["PII.Sensitive", "Finance.Reporting"]

The converter package may also ship a CLI, e.g.:

# Export OpenMetadata to Ossie YAML
osi-openmetadata import --api-url http://localhost:8585 --jwt-token <token> --glossary "Finance" -o finance_semantic_model.yaml

# Ingest Ossie YAML back into OpenMetadata
osi-openmetadata export -i finance_semantic_model.yaml --api-url http://localhost:8585 --jwt-token <token>

[benvdh]

Perhaps good to mention that the specification of a metric definition in OpenMetadata can be found here:
https://openmetadatastandards.org/governance/metric/#schema-specifications

[jpvilla5454]

@daniyarndh I am actually actively looking for a solution like this right now..having a bidirectional converter between OpenMetadata and Ossie would solve a real gap for our team.

Also noticed the converters seem to be split out into their own repo now. I’ve subscribed here to track progress, but if anyone starts kicking off work or has updates, please keep me in the loop!

[benvdh]

@jpvilla5454 There is a similar discussion going on in the openmetadata community (more about support of OpenMetadata for Ossie), where I've documented some of my findings (quick summary: Collate - the company behind OpenMetadata joined the Open Semantic Interchange consortium (the predecessor of Apache Ossie) in February 2025, in the 2.0 release blog post they mentioned OSI again, but I could not find any concrete documentation, PRs or issues on the matter):

open-metadata/OpenMetadata#31238

Just linking it here as well so that the two threads cross-reference.

[jbonofre]

It sounds super interesting. Let me know if you need my help to create a converter for OpenMetadata.