SQLAlchemy / Google Cloud SQL issue

main.py

from sqlalchemy import create_engine

engine = create_engine('mysql+gaerdbms:///myapp',
                        connect_args={"instance":"instancename"})
connection = engine.connect()

stack trace

(google-cloud-sql-test)smlynch@Sean-Macbook ~/Development/playground/google-cloud-sql-test $ python main.py 
Traceback (most recent call last):
  File "main.py", line 11, in <module>
    connection = engine.connect()
  File "/Users/smlynch/.virtualenvs/google-cloud-sql-test/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 2471, in connect
    return self._connection_cls(self, **kwargs)
  File "/Users/smlynch/.virtualenvs/google-cloud-sql-test/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 878, in __init__
    self.__connection = connection or engine.raw_connection()
  File "/Users/smlynch/.virtualenvs/google-cloud-sql-test/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 2557, in raw_connection
    return self.pool.unique_connection()
  File "/Users/smlynch/.virtualenvs/google-cloud-sql-test/lib/python2.7/site-packages/sqlalchemy/pool.py", line 184, in unique_connection
    return _ConnectionFairy(self).checkout()
  File "/Users/smlynch/.virtualenvs/google-cloud-sql-test/lib/python2.7/site-packages/sqlalchemy/pool.py", line 401, in __init__
    rec = self._connection_record = pool._do_get()
  File "/Users/smlynch/.virtualenvs/google-cloud-sql-test/lib/python2.7/site-packages/sqlalchemy/pool.py", line 822, in _do_get
    return self._create_connection()
  File "/Users/smlynch/.virtualenvs/google-cloud-sql-test/lib/python2.7/site-packages/sqlalchemy/pool.py", line 189, in _create_connection
    return _ConnectionRecord(self)
  File "/Users/smlynch/.virtualenvs/google-cloud-sql-test/lib/python2.7/site-packages/sqlalchemy/pool.py", line 282, in __init__
    self.connection = self.__connect()
  File "/Users/smlynch/.virtualenvs/google-cloud-sql-test/lib/python2.7/site-packages/sqlalchemy/pool.py", line 344, in __connect
    connection = self.__pool._creator()
  File "/Users/smlynch/.virtualenvs/google-cloud-sql-test/lib/python2.7/site-packages/sqlalchemy/engine/strategies.py", line 80, in connect
    return dialect.connect(*cargs, **cparams)
  File "/Users/smlynch/.virtualenvs/google-cloud-sql-test/lib/python2.7/site-packages/sqlalchemy/engine/default.py", line 281, in connect
    return self.dbapi.connect(*cargs, **cparams)
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/api/rdbms.py", line 69, in connect
    password=password)
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/storage/speckle/python/api/rdbms.py", line 745, in __init__
    self.OpenConnection()
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/storage/speckle/python/api/rdbms.py", line 768, in OpenConnection
    response = self.MakeRequest('OpenConnection', request)
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/storage/speckle/python/api/rdbms.py", line 875, in MakeRequest
    response = self.MakeRequestImpl(stub_method, request)
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/storage/speckle/python/api/rdbms_apiproxy.py", line 66, in MakeRequestImpl
    apiproxy_stub_map.MakeSyncCall('rdbms', stub_method, request, response)
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/api/apiproxy_stub_map.py", line 94, in MakeSyncCall
    return stubmap.MakeSyncCall(service, call, request, response)
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/api/apiproxy_stub_map.py", line 313, in MakeSyncCall
    assert stub, 'No api proxy found for service "%s"' % service
sqlalchemy.exc.DBAPIError: (AssertionError) No api proxy found for service "rdbms" None None