Keep asyncpg installed by default in the Postgres provider

providers/postgres/README.rst

@@ -60,6 +60,7 @@ PIP package                                 Version required
 ``psycopg2-binary``                         ``>=2.9.10; python_version >= "3.13"``
 ``psycopg[binary]``                         ``>=3.2.9; python_version < "3.14"``
 ``psycopg[binary]``                         ``>=3.3.3; python_version >= "3.14"``
+``asyncpg``                                 ``>=0.30.0``
 ==========================================  ======================================
 
 Optional cross provider package dependencies

providers/postgres/docs/changelog.rst

@@ -34,14 +34,19 @@ Breaking changes
 ~~~~~~~~~~~~~~~~
 
 .. note::
-    The default async metadata-database driver is now ``psycopg`` (psycopg3),
-    which is installed by default in place of ``asyncpg``. As a result, the
-    ``[psycopg]`` optional extra was removed and ``[asyncpg]`` was added.
-
-    Starting with Airflow 3.4.0, the default derived async connection URL changes from
+    On Airflow 3.4.0 and later, the default async metadata-database driver becomes
+    ``psycopg`` (psycopg3): the derived async connection URL changes from
     ``postgresql+asyncpg://`` to ``postgresql+psycopg_async://``, which is safe behind
-    transaction-mode PgBouncer with no extra configuration. To keep using asyncpg, install
-    ``apache-airflow-providers-postgres[asyncpg]`` and set
+    transaction-mode PgBouncer with no extra configuration. ``psycopg[binary]`` is now
+    installed by default to serve it.
+
+    ``asyncpg`` remains installed by default as well. This provider still supports Airflow
+    cores older than 3.4.0, which derive the async URL as ``postgresql+asyncpg://``
+    unconditionally and have no psycopg fallback — so asyncpg must stay present for them to
+    work. It will become opt-in-only (via the existing ``[asyncpg]`` extra) in a future
+    release once the minimum supported Airflow is 3.4.0.
+
+    To keep using asyncpg on Airflow 3.4.0+, set
     ``[database] sql_alchemy_conn_async = postgresql+asyncpg://...`` explicitly.
 
 * ``Switch the default async Postgres driver from asyncpg to psycopg3 (#69089)``

providers/postgres/docs/index.rst

@@ -108,6 +108,7 @@ PIP package                                 Version required
 ``psycopg2-binary``                         ``>=2.9.10; python_version >= "3.13"``
 ``psycopg[binary]``                         ``>=3.2.9; python_version < "3.14"``
 ``psycopg[binary]``                         ``>=3.3.3; python_version >= "3.14"``
+``asyncpg``                                 ``>=0.30.0``
 ==========================================  ======================================
 
 Optional cross provider package dependencies

providers/postgres/pyproject.toml

@@ -68,6 +68,13 @@ dependencies = [
     "psycopg2-binary>=2.9.10; python_version >= '3.13'",
     "psycopg[binary]>=3.2.9; python_version < '3.14'",
     "psycopg[binary]>=3.3.3; python_version >= '3.14'",
+    # asyncpg must stay a default dependency while this provider still supports Airflow
+    # cores older than 3.4.0: those cores derive the async metadata-DB URL as
+    # ``postgresql+asyncpg://`` unconditionally and have no psycopg_async fallback, so
+    # dropping asyncpg breaks their async engine. Make it opt-in-only (via the ``[asyncpg]``
+    # extra) only once the minimum supported Airflow is >= 3.4.0; tracked at
+    # https://github.com/apache/airflow/issues/68453
+    "asyncpg>=0.30.0",
 ]
 
 # The optional dependencies should be modified in place in the generated file