This is the first release of the **Airflow 3.0.0** Python client. It introduces compatibility with the new [Airflow 3.0 REST API](https://airflow.apache.org/docs/apache-airflow/3.0.0/stable-rest-api-ref.html), and includes several **breaking changes** and behavior updates.

Below is a list of important changes. Refer to individual endpoint documentation for full details.

- API v1 (`/api/v1`) has been dropped and replaced with API v2(`/api/v2`).

- **422 Validation Errors (instead of 400)**

The API now returns `422 Unprocessable Entity` for validation errors (e.g. bad payload, path params, or query params), instead of `400 Bad Request`.

- **Partial response support removed (`fields` parameter)**

Endpoints like `GET /dags` no longer support the `fields` query param for partial responses. Full objects are returned by default. This feature may return in a future 3.x release.

- Passing list in query parameters switched from ``form, non exploded`` to ``form, exploded`` i.e before ``?my_list=item1,item2`` now ``?my_list=item1&my_list=item2``

- **`execution_date` has been removed**

The previously deprecated `execution_date` parameter and fields are now fully removed. Use `logical_date` instead.

- **Datetime format updated to RFC3339-compliant**

Datetimes returned are now in [RFC3339](https://datatracker.ietf.org/doc/html/rfc3339) format (e.g. `2024-10-01T13:00:00Z`). Both `Z` and `+00:00` forms are accepted in inputs.

→ This change comes from FastAPI & Pydantic v2 behavior.

[More info](https://github.com/fastapi/fastapi/discussions/7693#discussioncomment-5143311)

- PATCH on ``DagRun`` and ``TaskInstance`` are more generic and allow in addition to update the resource state and the note content.

Therefore, the two legacy dedicated endpoints to update a ``DagRun`` note and ``TaskInstance`` note have been removed.

Same for the set task instance state, it is now handled by the broader PATCH on task instances.

- ``assets/queuedEvent`` endpoints have moved to ``assets/queuedEvents`` for consistency.

- **`dag_parsing` returns 409 for duplicates**

If a `DagPriorityParsingRequest` already exists, `POST /dag_parsing` now returns `409 Conflict` instead of `201 Created`.

- **Default value change in `clearTaskInstances`**

The `reset_dag_runs` field now defaults to `true` instead of `false`.

- **Pool name is no longer editable**

`PATCH /pools/{pool_name}` can no longer be used to rename a pool. Pool names are immutable via the API.

- **`logical_date` is now a required nullable field**

When triggering a DAG run (`POST /dags/{dag_id}/dagRuns`), `logical_date` is now required but can explicitly be set to `null`.