diff --git a/fulcrm_webhook.install b/fulcrm_webhook.install
index 69f3d9b..8f7bab8 100644
--- a/fulcrm_webhook.install
+++ b/fulcrm_webhook.install
@@ -2,5 +2,41 @@
 
 function fulcrm_webhook_install() {
     $url = fulcrm_uuid_uuid4();
-    variable_set( 'fulcrm_webhook_url', $url );
+    variable_set( 'fulcrm_webhook_url', variable_get( 'fulcrm_webhook_url', $url ) );
+}
+
+function fulcrm_webhook_schema() {
+  $schema[ 'fulcrm_webhook_entity_mapping' ] = array( 'description' => '',
+                                                      'fields' => array( 'entity_type' => array( 'type' => 'varchar',
+                                                                                                 'length' => 128,
+                                                                                                 'not null' => TRUE,
+                                                                                                 ),
+                                                                         'bundle' => array( 'description' => 'The {node_type}.type of this node.',
+                                                                                            'type' => 'varchar',
+                                                                                            'length' => 128,
+                                                                                            'default' => NULL,
+                                                                                            ),
+                                                                         'entity_id' => array( 'type' => 'int',
+                                                                                               'unsigned' => TRUE,
+                                                                                               'not null' => TRUE,
+                                                                                               'description' => 'The entity id this data is attached to',
+                                                                                               ),
+                                                                         'fulcrm_type' => array( 'type' => 'varchar',
+                                                                                                'length' => 128,
+                                                                                                'not null' => TRUE,
+                                                                                                'description' => 'The fulcrm model/type',
+                                                                                                ),
+                                                                         'fulcrm_pk' => array( 'type' => 'int',
+                                                                                               'unsigned' => TRUE,
+                                                                                               'not null' => TRUE,
+                                                                                               'description' => 'The fulcrm model primary key',
+                                                                                               ),
+                                                                         ),
+                                                      'primary key' => array( 'entity_type', 'bundle', 'entity_id' ),
+                                                      'unique keys' => array( 'fulcrm_key' => array( 'fulcrm_type', 'fulcrm_pk' ),
+                                                                              ),
+                                                      'indexes' => array( 'fulcrm_index' => array( 'fulcrm_type', 'fulcrm_pk' ),
+                                                                          ),
+                                                      );
+  return $schema;
 }