OSI is now Apache Ossie (Incubating)

If you've been following the Open Semantic Interchange (OSI) project, the open specification for semantic layer and ontology, there's an important update. The project has been accepted into the Apache Incubator. Along with this transition the name is changing to Apache Ossie (Incubating).

The spec, the community, and the mission haven't changed, but the name, governance home, and long-term trajectory have.

Why the new name?

When work on this initiative was started, it was called the Open Semantic Interchange. This quickly got shortened to OSI, which became the GitHub repo name. Unfortunately this has caused some confusion along the way as the acronym OSI is used frequently to refer to Open Source Initiative.

Now although it might be fun to say OSI OSI (Open Source Initiative Open Semantic Interchange), the community decided it was best to rename the project. Through discussion the community decided on Ossie, and with acceptance into the Apache incubator, it is now Apache Ossie (Incubating). In addition to the rename, a mascot has been chosen, a kangaroo. The Ossie Kangaroo is dedicated to carrying semantic metadata in its pouch from platform to platform. That is, it’s making your data hop.

In short:

• The project is Apache Ossie (Incubating)
• Any reference to "OSI" in the project are historical (and will slowly be removed)
• There is a kangaroo logo

If you've been building on Open Semantic Interchange, nothing breaks. The name changed, but the spec didn't.

What is Ossie?

Ossie is an open specification for both semantic layer and ontology. It defines a vendor-neutral format for expressing business metrics, dimensions, relationships, as well as broader business concepts and rules. It allows any tool or platform in your semantic layer stack to produce and consume semantic definitions without loss of meaning.

The problem it solves is important: it ensures that a given business concept (say, "Monthly Active Users") can be defined, interpreted, and resolved consistently across an organization's CRM, data warehouse, and BI tools. When a human analyst or an AI agent runs a query, they shouldn't have to guess which definition is correct. Ossie provides the shared, machine-readable format that encodes not just the data but the intent and business meaning behind it.

Why the Apache Software Foundation (ASF)?

Incubating Ossie with the Apache Software Foundation ensures that it remains an open standard with no single controlling entity. The goal of Ossie is to provide industry-wide standardization of semantic data, and to that end ensuring that it has a vendor neutral ground to operate in is imperative.

Under incubation, Ossie operates with public mailing lists, GitHub-based development, a formal discussion-and-vote process for spec changes, and committership earned through contribution rather than employer affiliation. Note that as part of this transition, all mailing lists referring to Open Semantic Interchange will be retired; community members should use the ASF-provided project resources that are linked below instead.

Importance of the Ossie community

Ossie didn't start as a single-company project, it has been a community effort. Since the repository opened in November 2025:

• More than 100 commits and 35 merged pull requests have landed from contributors at Snowflake, Salesforce, Databricks, dbt Labs, RelationalAI, GoodData, and Honeydew
• The participating coalition has grown from 17 launch partners to more than 50 organizations
• Three working groups (Metric Language, Catalog, and Ontology) operate with dedicated leads, meetings and public channels
• Implementations including the Ossie-to-dbt Semantic Layer converters and an Apache Polaris™ converter are already merged

What's next

dbt Labs was one of the founding organizations behind Open Semantic Interchange, and we'll continue as an active contributor to the project as it grows under ASF governance.

As with any Apache project, the community will decide the direction together. That said, there are a few areas we're excited about and hope to work with the community to contribute proposals for:

• Deepening the spec's expressiveness to accommodate what real enterprise models demand, including an expression language spec, advanced metric logic, windowing functions and complex relationships
• Building converters for additional platforms and frameworks so that adopting Ossie doesn't require ripping out what you already have
• A standardized semantic query specification that any engine can support
• Integration with Apache Polaris so that semantic models are discoverable directly from the catalog

None of this is predetermined. It will go through the same open discussion-and-vote process as everything else in the project.

Get involved

Ossie is transitioning to ASF infrastructure as part of incubation. Watch for updates on the new project website, join the development mailing list, collaborate on GitHub and join the Ossie Slack workspace.

Whether you're building an AI agent, BI tool, or a query engine that needs to understand business context, Ossie is the community working to make sure you don't have to tackle semantic interoperability alone.