docs: Update public interface documentation for Airflow 3.0+ for metadata direct access change

Author: sunank200

airflow-core/docs/conf.py

@@ -120,7 +120,6 @@
 
 PACKAGES_THAT_WE_SHOULD_ADD_TO_API_DOCS = {
     "hooks",
-    "decorators",
     "example_dags",
     "executors",
     "operators",
@@ -140,15 +139,7 @@
 
 MODELS_THAT_SHOULD_BE_INCLUDED_IN_API_DOCS: set[str] = {
     "baseoperator.py",
-    "connection.py",
-    "dag.py",
-    "dagrun.py",
-    "dagbag.py",
     "param.py",
-    "taskinstance.py",
-    "taskinstancekey.py",
-    "variable.py",
-    "xcom.py",
 }
 
 

airflow-core/docs/core-concepts/params.rst

@@ -32,7 +32,7 @@ If the user-supplied values don't pass validation, Airflow shows a warning inste
 DAG-level Params
 ----------------
 
-To add Params to a :class:`~airflow.models.dag.DAG`, initialize it with the ``params`` kwarg.
+To add Params to a :class:`~airflow.sdk.DAG`, initialize it with the ``params`` kwarg.
 Use a dictionary that maps Param names to either a :class:`~airflow.sdk.definitions.param.Param` or an object indicating the parameter's default value.
 
 .. code-block::

airflow-core/docs/core-concepts/xcoms.rst

@@ -25,6 +25,11 @@ XComs (short for "cross-communications") are a mechanism that let :doc:`tasks` t
 
 An XCom is identified by a ``key`` (essentially its name), as well as the ``task_id`` and ``dag_id`` it came from. They can have any serializable value (including objects that are decorated with ``@dataclass`` or ``@attr.define``, see :ref:`TaskFlow arguments <concepts:arbitrary-arguments>`:), but they are only designed for small amounts of data; do not use them to pass around large values, like dataframes.
 
+.. versionchanged:: 3.0
+
+   In Airflow 3.0+, XCom operations should be performed through the Task Context using
+   :func:`~airflow.sdk.get_current_context`. Direct database access is not possible.
+
 XComs are explicitly "pushed" and "pulled" to/from their storage using the ``xcom_push`` and ``xcom_pull`` methods on Task Instances.
 
 To push a value within a task called **"task-1"** that will be used by another task:
@@ -73,8 +78,27 @@ An example of pushing multiple XComs and pulling them individually:
         # Pulling entire xcom data from push_multiple task
         data = context["ti"].xcom_pull(task_ids="push_multiple", key="return_value")
 
+.. versionchanged:: 3.0
+
+   In Airflow 3.0+, you can also use the Task Context directly for XCom operations:
+
+   .. code-block:: python
+
+       from airflow.sdk import get_current_context
 
 
+       @task
+       def example_task():
+           context = get_current_context()
+           ti = context["ti"]
+
+           # Push XCom
+           ti.xcom_push(key="my_key", value="my_value")
+
+           # Pull XCom
+           value = ti.xcom_pull(task_ids="previous_task", key="my_key")
+           return value
+
 .. note::
 
   If the first task run is not succeeded then on every retry task XComs will be cleared to make the task run idempotent.
@@ -91,7 +115,12 @@ Custom XCom Backends
 
 The XCom system has interchangeable backends, and you can set which backend is being used via the ``xcom_backend`` configuration option.
 
-If you want to implement your own backend, you should subclass :class:`~airflow.models.xcom.BaseXCom`, and override the ``serialize_value`` and ``deserialize_value`` methods.
+If you want to implement your own backend, you should subclass :class:`~airflow.sdk.execution_time.xcom.XCom`, and override the ``serialize_value`` and ``deserialize_value`` methods.
+
+.. versionchanged:: 3.0
+
+   The base class for custom XCom backends is now :class:`~airflow.sdk.execution_time.xcom.XCom`
+   from the airflow.sdk namespace.
 
 You can override the ``purge`` method in the ``BaseXCom`` class to have control over purging the xcom data from the custom backend. This will be called as part of ``delete``.
 
@@ -104,6 +133,6 @@ If you can exec into a terminal in an Airflow container, you can then print out
 
 .. code-block:: python
 
-    from airflow.models.xcom import XCom
+    from airflow.sdk.execution_time.xcom import XCom
 
     print(XCom.__name__)