Start the Unity Catalog OSS server (base URL defaults to http://localhost:8080); the server exposes its REST API at /api/2.1/unity-catalog — no authentication is required in the default OSS configuration but production deployments should add an auth layer
Create a catalog via POST /api/2.1/unity-catalog/catalogs with body {"name": "my_catalog", "comment": "..."}; then create a schema within it via POST /api/2.1/unity-catalog/schemas with {"catalog_name": "my_catalog", "name": "my_schema"}
Register a table via POST /api/2.1/unity-catalog/tables with a payload specifying catalog_name, schema_name, name, table_type (EXTERNAL), data_source_format (DELTA or PARQUET), columns array, and storage_location pointing to the file path
List tables in a schema via GET /api/2.1/unity-catalog/tables?catalog_name=my_catalog&schema_name=my_schema; retrieve a specific table's metadata via GET /api/2.1/unity-catalog/tables/{full_name} where full_name is catalog.schema.table
Connect a query engine that supports Unity Catalog (e.g., Apache Spark with the unitycatalog-spark connector) by pointing its catalog configuration to the UC OSS REST endpoint; engines read table metadata from UC and access data files at the storage_location
Known gotchas
Unity Catalog OSS REST API paths and payloads are still evolving; the project documentation notes that APIs should not be assumed stable — pin your client code to a specific UC release version and review changelog entries before upgrading
The Unity Catalog REST API manages metadata only; it does not proxy queries to underlying storage — you need a separate query engine (Spark, DuckDB with the UC connector, etc.) to actually read or write table data
Unity Catalog OSS uses a three-level namespace (catalog.schema.table) like Databricks Unity Catalog but has no built-in access control in the open-source version; add an external authorization layer before exposing the endpoint outside a trusted network
Give your agent this knowledge — and 200+ more routes
One MCP install gives any agent live access to the full route map, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp