Apache Ossie (incubating)

Apache Ossie is a collaborative, open-source effort dedicated to standardizing and streamlining semantic model exchange and utilization across the diverse array of tools and platforms within the data analytics, AI, and BI ecosystem. Our shared vision is to establish a common, vendor-agnostic semantic model specification, promoting unparalleled interoperability, efficiency, and collaboration among all participants. By providing a single, consistent source of truth, this vendor-agnostic standard ensures that your data's definitions and value remain consistent as they are interchanged between AI agents, BI platforms, and all other tools in your ecosystem, eliminating inconsistencies across your different tools.

Apache Ossie was formerly known as Open Semantic Interchange (OSI).

Apache Ossie provides a single JSON- and YAML-based specification that any tool can read and write, addressing the semantic fragmentation common across today's data stack: the same KPI defined differently across tools, teams spending significant effort manually reconciling definitions, and AI agents producing unreliable outputs grounded in inconsistent business logic.

What's in this repository

• bi-sql-examples/ — SQL query shapes generated by BI tools that Ossie aims to support.
• compliance/ — Portability grader and query test cases for the Relational Query Interface.
• core-spec/ — The Ossie core specification (spec.md), the machine-readable schema (spec.yaml, ossie-schema.json), and accompanying documentation.
• dev/ — Development utilities.
• docs/ — Project documentation and overview.
• examples/ — Example semantic models, including a complete TPC-DS model.
• extensions/ — Community registry of dialect and vendor tokens used in extension metadata.
• ontology/ — The ontology specification (ontology.md), its machine-readable schemas (ontology.json, mapping.json), and supporting documentation.
• python/ — Python SDK with Pydantic v2 models for parsing, validating, and serializing Ossie documents.
• scripts/ — Repository tooling, including generation of the spec's type definitions.
• validation/ — Tooling for validating semantic models against the Ossie schema.

Reference converters that translate between Ossie and other semantic formats (e.g., dbt, GoodData, Polaris, Salesforce) live in the apache/ossie-converters repository.

Get involved

• Contribute: See CONTRIBUTING.md for how to propose specification changes, contribute code, and participate in the community.
• Roadmap: See ROADMAP.md for current working groups, future efforts, and planned enhancements informed by community discussion.
• Discuss: Join the conversation on GitHub Discussions and Issues.
• Join the Slack community: Chat directly with contributors on Slack.