diff --git a/tests/charms/layers/native-ci/layer.yaml b/tests/charms/layers/native-ci/layer.yaml
index edc8839..138d9d3 100644
--- a/tests/charms/layers/native-ci/layer.yaml
+++ b/tests/charms/layers/native-ci/layer.yaml
@@ -1,4 +1,7 @@
-includes: ['layer:basic']
+includes:
+    - 'layer:basic'
+    - 'interface:mysql'
+    
 options:
     basic:
         use_venv: false
diff --git a/tests/charms/layers/native-ci/metadata.yaml b/tests/charms/layers/native-ci/metadata.yaml
index 6acf296..0460e48 100644
--- a/tests/charms/layers/native-ci/metadata.yaml
+++ b/tests/charms/layers/native-ci/metadata.yaml
@@ -4,3 +4,9 @@
 maintainer: Adam Israel <adam.israel@canonical.com>
 subordinate: false
 series: ['xenial']
+provides:
+    db:
+        interface: mysql
+requires:
+    app:
+        interface: mysql
diff --git a/tests/charms/layers/native-ci/reactive/native-ci.py b/tests/charms/layers/native-ci/reactive/native-ci.py
index 17bf5f4..9e5fe67 100644
--- a/tests/charms/layers/native-ci/reactive/native-ci.py
+++ b/tests/charms/layers/native-ci/reactive/native-ci.py
@@ -42,3 +42,21 @@
         action_set({'output': intval})
     finally:
         clear_flag('actions.testint')
+
+
+@when('db.joined')
+def provides_db(db):
+    """Simulate providing database credentials."""
+    db.configure(
+        database="mydb",
+        user="myuser",
+        password="mypassword",
+        host="myhost",
+        slave="myslave",
+    )
+
+
+@when('db.available')
+def requires_db(db):
+    """Simulate receiving database credentials."""
+    pass
diff --git a/tests/charms/layers/proxy-ci/metadata.yaml b/tests/charms/layers/proxy-ci/metadata.yaml
index b96abe4..bb00a03 100644
--- a/tests/charms/layers/proxy-ci/metadata.yaml
+++ b/tests/charms/layers/proxy-ci/metadata.yaml
@@ -10,3 +10,9 @@
 subordinate: false
 series:
   - xenial
+provides:
+    db:
+        interface: mysql
+requires:
+    app:
+        interface: mysql
diff --git a/tests/charms/layers/proxy-ci/reactive/proxy_ci.py b/tests/charms/layers/proxy-ci/reactive/proxy_ci.py
index 98b7f96..9c0136e 100644
--- a/tests/charms/layers/proxy-ci/reactive/proxy_ci.py
+++ b/tests/charms/layers/proxy-ci/reactive/proxy_ci.py
@@ -32,3 +32,21 @@
         action_set({'output': result})
     finally:
         clear_flag('actions.test')
+
+
+@when('db.joined')
+def provides_db(db):
+    """Simulate providing database credentials."""
+    db.configure(
+        database="mydb",
+        user="myuser",
+        password="mypassword",
+        host="myhost",
+        slave="myslave",
+    )
+
+
+@when('db.available')
+def requires_db(db):
+    """Simulate receiving database credentials."""
+    pass