The Fabric family

Fabric Runway is one vertical in the Fabric product family. It owns a single domain — governed Databricks delivery — and delegates everything else to the product that owns it. The boundary is deliberate: Runway implements no mutation engine, no Databricks deploy SDK, and no evaluation platform of its own.

Fabric Platform — the law

Every externally meaningful state change is a registered action executed through Platform's governed mutation pipeline (createGovernedActionHost()). Platform creates the durable invocation before execution, evaluates policy, validates state transitions, records adapter attempts, and appends the audit events. Runway consumes this pipeline; it does not own one.

Fabric Harness — builds and ships them

Harness owns the Databricks transport surface: Unity Catalog Volume upload and streaming, content and tree digests, databricks bundle validate/deploy, Databricks App snapshot activation, workspace identity helpers, and typed secret authoring. Runway calls these public APIs at its single Databricks adapter boundary — it never shells out to databricks itself.

Fabric Experiments — judges them

Experiments owns versioned datasets, evaluation runs, BDD, live workspace certification, and release evidence. Runway requests a run through the typed API client and accepts a gate verdict only when it comes from the trusted system actor and matches the exact requested run.

The invariant

• Harness tools and agents may request Runway actions, but they never write Runway business state directly — they go through the same governed pipeline as everyone else.
• Experiments may certify a release, but it is never itself a production mutation path.

This is what lets Runway stay thin while still being the single, audited front door to Databricks production.