diff --git a/functions/firebase/main.py b/functions/firebase/main.py
new file mode 100644
index 00000000000..b0f79e76881
--- /dev/null
+++ b/functions/firebase/main.py
@@ -0,0 +1,71 @@
+# Copyright 2018 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the 'License');
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an 'AS IS' BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# [START functions_firebase_rtdb]
+# [START functions_firebase_firestore]
+# [START functions_firebase_auth]
+import json
+# [END functions_firebase_rtdb]
+# [END functions_firebase_firestore]
+# [END functions_firebase_auth]
+
+
+# [START functions_firebase_rtdb]
+def hello_rtdb(data, context):
+    """ Triggered by a change to a Firebase RTDB reference.
+    Args:
+        data (dict): The event payload.
+        context (google.cloud.functions.Context): Metadata for the event.
+    """
+    trigger_resource = context.resource
+
+    print('Function triggered by change to: %s' % trigger_resource)
+    print('Admin?: %s' % data.get("admin", False))
+    print('Delta:')
+    print(json.dumps(data["delta"]))
+# [END functions_firebase_rtdb]
+
+
+# [START functions_firebase_firestore]
+def hello_firestore(data, context):
+    """ Triggered by a change to a Firestore document.
+    Args:
+        data (dict): The event payload.
+        context (google.cloud.functions.Context): Metadata for the event.
+    """
+    trigger_resource = context.resource
+
+    print('Function triggered by change to: %s' % trigger_resource)
+
+    print('\nOld value:')
+    print(json.dumps(data["oldValue"]))
+
+    print('\nNew value:')
+    print(json.dumps(data["value"]))
+# [END functions_firebase_firestore]
+
+
+# [START functions_firebase_auth]
+def hello_auth(data, context):
+    """ Triggered by creation or deletion of a Firebase Auth user object.
+     Args:
+            data (dict): The event payload.
+            context (google.cloud.functions.Context): Metadata for the event.
+    """
+    print('Function triggered by creation/deletion of user: %s' % data["uid"])
+    print('Created at: %s' % data["metadata"]["createdAt"])
+
+    if 'email' in data:
+        print('Email: %s' % data["email"])
+# [END functions_firebase_auth]
diff --git a/functions/firebase/main_test.py b/functions/firebase/main_test.py
new file mode 100644
index 00000000000..df30af46134
--- /dev/null
+++ b/functions/firebase/main_test.py
@@ -0,0 +1,85 @@
+# Copyright 2018 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the 'License');
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an 'AS IS' BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from datetime import datetime
+import json
+
+import uuid
+
+import main
+
+
+class Context(object):
+    pass
+
+
+def test_rtdb(capsys):
+    data_id = str(uuid.uuid4())
+    resource_id = str(uuid.uuid4())
+
+    data = {
+        'admin': True,
+        'delta': {'id': data_id}
+    }
+
+    context = Context()
+    context.resource = resource_id
+
+    main.hello_rtdb(data, context)
+
+    out, _ = capsys.readouterr()
+
+    assert ('Function triggered by change to: %s' % resource_id) in out
+    assert 'Admin?: True' in out
+    assert data_id in out
+
+
+def test_firestore(capsys):
+    resource_id = str(uuid.uuid4())
+
+    context = Context()
+    context.resource = resource_id
+
+    data = {
+        'oldValue': {'uuid': str(uuid.uuid4())},
+        'value': {'uuid': str(uuid.uuid4())}
+    }
+
+    main.hello_firestore(data, context)
+
+    out, _ = capsys.readouterr()
+
+    assert ('Function triggered by change to: %s' % resource_id) in out
+    assert json.dumps(data['oldValue']) in out
+    assert json.dumps(data['value']) in out
+
+
+def test_auth(capsys):
+    user_id = str(uuid.uuid4())
+    date_string = datetime.now().isoformat()
+    email_string = '%s@%s.com' % (uuid.uuid4(), uuid.uuid4())
+
+    data = {
+        'uid': user_id,
+        'metadata': {'createdAt': date_string},
+        'email': email_string
+    }
+
+    main.hello_auth(data, None)
+
+    out, _ = capsys.readouterr()
+
+    assert user_id in out
+    assert date_string in out
+    assert email_string in out