Skip to main content
Apache Ossie (OSI), formerly the Open Semantic Interchange, is a vendor-neutral, open-source specification for portable semantic model definitions. It gives BI tools, AI agents, and warehouses a shared YAML/JSON format for datasets, relationships, fields, and metrics, so the same definitions can travel across tools without manual reconciliation. It is now an incubating project at the Apache Software Foundation. Honeydew is one of the founding partners of Apache Ossie (OSI), alongside Snowflake, Salesforce, and dbt. Portable semantics are core to how Honeydew approaches a semantic layer: the same metric or attribute definition should mean the same thing in every tool that consumes it. See the announcement post for context on why Honeydew joined.
Apache Ossie is an early specification under active development (current draft 0.2.0.dev0). Concepts, field names, and mappings may change before the specification stabilizes.

​
Concept Mapping

Apache Ossie (OSI) and Honeydew model the same problem space, but the granularity differs. The table below maps each Apache Ossie concept to its Honeydew equivalent.

​
Concepts Honeydew Adds Beyond Apache Ossie (OSI)

Apache Ossie defines the portable metadata layer. Honeydew implements that layer and adds the operational machinery a semantic layer needs in production:
  • Query compiler and BI integration — metrics and attributes compile to warehouse SQL exposed through SQL, XMLA, GraphQL, and MCP interfaces, with native integrations on top of those interfaces into Power BI, Tableau, Excel, and other BI tools.
  • AI Context Layer — Apache Ossie carries ai_context metadata on individual objects; Honeydew adds a full context layer above the semantic layer (instructions, analytical skills, external business knowledge, and historical memory) and an agentic AI analysis engine that combines context retrieval with semantic compilation — deep analysis, agents, Slack, and Teams apps.
  • Domains — hierarchical projections of the same semantic model for different audiences (finance vs. marketing, regional sales, an AI agent’s scope). A domain selects entities and fields, applies mandatory filters, and overrides parameters; domains extend and compose other domains, so one model serves many perspectives without duplication.
  • Aggregate awareness — semantic-aware query rewriting to pre-aggregated tables, alongside incremental aggregate updates and entity caching for further performance.
  • Security and access control — row-level security and access control, enforced from the query interface down to the warehouse.
  • Workflow, environments, and deployment — the semantic model is YAML and inherently git-native; Honeydew adds the workflow around it: workspaces, environments, and promotion paths for dev/staging/prod.

​
Converting To and From Apache Ossie (OSI)

Honeydew provides a bidirectional converter between Apache Ossie and the Honeydew workspace format, maintained in the Apache Ossie repository under converters/honeydew:
  • Apache Ossie → Honeydew — import an Apache Ossie semantic model and produce a Honeydew workspace (entities, relations, attributes, metrics, AI metadata). See Import Tools.
  • Honeydew → Apache Ossie — export a Honeydew workspace as an Apache Ossie semantic model for consumption by other tools that support it.
Because Apache Ossie is still evolving, the converter tracks the current draft of the specification and may change as the specification stabilizes.

​
Stay Updated

The Apache Ossie (OSI) specification is evolving. Track progress on the Apache Ossie GitHub repository and working groups.