Crate unitycatalog_delta_api 

Portable Unity Catalog Delta v1 REST API.

This crate owns the Delta API semantics — the hand-written wire models, the catalog-managed table contract, the commit coordinator, and the updateTable action dispatcher — behind a narrow backend port. Any server can serve the identical /delta/v1 surface by implementing DeltaBackend over its own storage, credential vending, and authorization; all the Delta business logic is shared here, so the behavior is identical by construction.

It depends only on axum, async-trait, serde, uuid, and thiserror — it does not depend on any server crate, so a downstream server (mangrove, lakekeeper, …) takes this single dependency and nothing else.

Examples

Implement DeltaBackend over your own storage, then hand it to get_router to serve the entire /delta/v1 surface. Here the in-memory backend from the testing feature stands in for a real one:

use unitycatalog_delta_api::get_router;
use unitycatalog_delta_api::testing::InMemoryDeltaBackend;

// `InMemoryDeltaBackend` implements `DeltaBackend<()>`, so the context type
// is `()`. A real server uses its own request-context type here.
let router: axum::Router = get_router::<InMemoryDeltaBackend, ()>(InMemoryDeltaBackend::new());

Layout

• models — hand-written serde wire DTOs (kebab-case JSON).
• error — the decoupled error contract (DeltaApiError + DeltaBackendError).
• column — the portable UC column model used by the contract.
• config — getConfig support: capability-driven endpoint list + protocol version negotiation.
• contract — the managed-table contract + Delta↔UC column mapping.
• coordinator — the commit coordinator (arbitration + backfill).
• authz — the DeltaAction vocabulary the handler authorizes with.
• backend — the DeltaBackend port trait + its coordinate/request types.
• handler — the DeltaApiHandler trait + the generic blanket impl.
• router — the axum router mounting all 12 operations.

Re-exports

pub use authz::DeltaAction;

pub use backend::DeltaBackend;

pub use backend::DeltaCapabilities;

pub use error::DeltaApiError;

pub use error::DeltaApiResult;

pub use error::DeltaBackendError;

pub use handler::DeltaApiHandler;

pub use router::get_router;

Modules

authz

The authorization vocabulary the handler speaks to the backend.

backend

The DeltaBackend port: the narrow backend interface the Delta business logic calls.

column

Portable UC column model used by the managed-table contract.

config

getConfig support: the capability-driven endpoint list and protocol-version negotiation.

contract

The UC catalog-managed Delta table contract, the stored-property projection, and the Delta-API ↔ UC column conversion.

coordinator

Delta catalog-managed commit coordinator.

error

The /delta/v1 error contract, decoupled from any server’s internal error.

handler

The DeltaApiHandler trait and its generic implementation over a DeltaBackend.

models

Hand-written serde models for the UC Delta REST API (/delta/v1/...).

router

Axum router for the UC Delta REST API (/delta/v1/...).

testingtesting

An in-memory DeltaBackend for exercising the Delta business logic without a real backend.