diff --git a/inc/activities.php b/inc/activities.php
index 8d12fb6..108e358 100644
--- a/inc/activities.php
+++ b/inc/activities.php
@@ -48,9 +48,18 @@ function persist_activity( $activity ) {
             array( 'status' => 400 )
         );
     }
+    if ( !array_key_exists( 'type', $activity ) ) {
+        return new \WP_Error(
+            'invalid_activity',
+            __( 'Activity must have a "type" field', 'pterotype' ),
+            array( 'status' => 400 )
+        );
+    }
     $activitypub_id = $activity['id'];
+    $type = $activity['type'];
     $wpdb->replace( 'pterotype_activities', array(
             'activitypub_id' => $activitypub_id,
+            'type' => $type,
             'activity' => wp_json_encode( $activity )
     ) );
     return $activity;
@@ -58,6 +67,14 @@ function persist_activity( $activity ) {
 
 function create_local_activity( $activity ) {
     global $wpdb;
+    if ( !array_key_exists( 'type', $activity ) ) {
+        return new \WP_Error(
+            'invalid_activity',
+            __( 'Activity must have a "type" field', 'pterotype' ),
+            array( 'status' => 400 )
+        );
+    }
+    $type = $activity['type'];
     $res = $wpdb->insert( 'pterotype_activities', array(
         'activity' => wp_json_encode( $activity )
     ) );
@@ -74,9 +91,10 @@ function create_local_activity( $activity ) {
         array(
             'id' => $activity_id,
             'activitypub_id' => $activity_url,
-            'activity' => $activity
+            'type' => $type,
+            'activity' => wp_json_encode( $activity ),
         ),
-        array( '%d', '%s', '%s' )
+        array( '%d', '%s', '%s', '%s' )
     );
     if ( !$res ) {
         return new \WP_Error(
diff --git a/inc/migrations.php b/inc/migrations.php
index fe79650..ecea4ee 100644
--- a/inc/migrations.php
+++ b/inc/migrations.php
@@ -4,23 +4,31 @@ Poor man's migration system
 */
 namespace migrations;
 
+$previous_version = get_option( 'pterotype_previously_migrated_version' );
+if ( !$previous_version ) {
+    $previous_version = '0.0.0';
+}
+
 /*
 It's okay to add new queries to this function, but don't ever delete queries.
 */
 function run_migrations() {
-    $previous_version = get_option( 'pterotype_previously_migrated_version' );
-    if ( !$previous_version ) {
-        $previous_version = '0.0.0';
-    }
+    global $previous_version;
     if ( version_compare( $previous_version, PTEROTYPE_VERSION, '>=' ) ) {
         return;
     }
-    if ( version_compare( $previous_version, '0.0.1', '<' ) ) {
-        migration_0_0_1();
-    }
+    apply_migration( '0.0.1', 'migration_0_0_1' );
+    apply_migration( '0.0.2', 'migration_0_0_2' );
     update_option( 'pterotype_previously_migrated_version', PTEROTYPE_VERSION );
 }
 
+function apply_migration( $version, $migration_func ) {
+    global $previous_version;
+    if ( version_compare( $previous_version, $version, '<' ) ) {
+        call_user_func( __NAMESPACE__ . '\\' . $migration_func );
+    }
+}
+
 function migration_0_0_1() {
     global $wpdb;
     $wpdb->query(
@@ -130,4 +138,22 @@ function migration_0_0_1() {
         "
     );
 }
+
+function migration_0_0_2() {
+    global $wpdb;
+    $wpdb->query(
+        "
+        ALTER TABLE pterotype_objects 
+            MODIFY object JSON NOT NULL,
+            ADD type VARCHAR(50) NOT NULL;
+        "
+    );
+    $wpdb->query(
+        "
+        ALTER TABLE pterotype_activities
+            MODIFY activity JSON NOT NULL,
+            ADD type VARCHAR(50) NOT NULL;
+        "
+    );
+}
 ?>
diff --git a/inc/objects.php b/inc/objects.php
index a4f6440..ffd2c5a 100644
--- a/inc/objects.php
+++ b/inc/objects.php
@@ -6,6 +6,13 @@ namespace objects;
 
 function create_local_object( $object ) {
     global $wpdb;
+    if ( !array_key_exists( 'type', $object) ) {
+        return new \WP_Error(
+            'invalid_object',
+            __( 'Object must have a "type" field', 'pterotype' ),
+            array( 'status' => 400 )
+        );
+    }
     $res = $wpdb->insert( 'pterotype_objects', array(
         'object' => wp_json_encode( $object )
     ) );
@@ -15,6 +22,7 @@ function create_local_object( $object ) {
         );
     }
     $object_id = $wpdb->insert_id;
+    $type = $object['type'];
     $object_url = get_rest_url( null, sprintf( '/pterotype/v1/object/%d', $object_id ) );
     $object['id'] = $object_url;
     $res = $wpdb->replace(
@@ -22,9 +30,10 @@ function create_local_object( $object ) {
         array (
             'id' => $object_id,
             'activitypub_id' => $object_url,
+            'type' => $type,
             'object' => wp_json_encode( $object )
         ),
-        array( '%d', '%s', '%s' )
+        array( '%d', '%s', '%s', '%s' )
     );
     if ( !$res ) {
         return new \WP_Error(
@@ -43,6 +52,13 @@ function upsert_object( $object ) {
             array( 'status' => 400 )
         );
     }
+    if ( !array_key_exists( 'type', $object) ) {
+        return new \WP_Error(
+            'invalid_object',
+            __( 'Object must have a "type" field', 'pterotype' ),
+            array( 'status' => 400 )
+        );
+    }
     $row = $wpdb->get_row( $wpdb->prepare(
         'SELECT * FROM pterotype_objects WHERE activitypub_url = %s', $object['id']
     ) );
@@ -52,6 +68,7 @@ function upsert_object( $object ) {
             'pterotype_objects',
             array(
                 'activitypub_id' => $object['id'],
+                'type' => $object['type'],
                 'object' => wp_json_encode( $object )
             )
         );
@@ -61,9 +78,10 @@ function upsert_object( $object ) {
             array(
                 'id' => $row->id,
                 'activitypub_id' => $object['id'],
+                'type' => $object['type'],
                 'object' => wp_json_encode( $object )
             ),
-            array( '%d', '%s', '%s' )
+            array( '%d', '%s', '%s', '%s' )
         );
         $row = new stdClass();
         $row->id = $wpdb->insert_id;
diff --git a/pterotype.php b/pterotype.php
index 93a10f1..c4e911e 100644
--- a/pterotype.php
+++ b/pterotype.php
@@ -4,7 +4,7 @@ Plugin Name: Pterotype
 */
 require_once plugin_dir_path( __FILE__ ) . 'inc/init.php';
 
-define( 'PTEROTYPE_VERSION', '0.0.1' );
+define( 'PTEROTYPE_VERSION', '0.0.2' );
 
 function pterotype_init() {
     do_action( 'pterotype_init' );