Authoring Language SDK Tasks (Shared Foundation)

Airflow language SDKs let you implement task logic in a language other than Python while the DAG and its scheduling stay in Python. This skill describes the parts that are identical across every language SDK. Each language has its own companion skill for the native API, build tooling, and runtime — see Per-language skills.

Experimental. The language SDKs are in preview. APIs and artifact coordinates may change.

The model

A DAG is authored in Python as usual. Tasks that should run in another language are declared as stubs routed to a dedicated queue. At runtime, Airflow hands a stub task to a coordinator that launches a short-lived native subprocess for that one task instance, runs your compiled/native code, and shuts the subprocess down.

Consequences that hold for every language SDK:

• One subprocess per task instance — there is no shared in-process state between task instances. Pass data via XCom or an external store.
• The DAG, schedule, retries, and queue routing live in Python. The native side only implements task logic.
• Data crossing the boundary is JSON. See The XCom-as-JSON contract.