diff --git a/projects/packages/jetpack-mu-wpcom/.phan/baseline.php b/projects/packages/jetpack-mu-wpcom/.phan/baseline.php
index bb58e6850074b..f8dea226fcd09 100644
--- a/projects/packages/jetpack-mu-wpcom/.phan/baseline.php
+++ b/projects/packages/jetpack-mu-wpcom/.phan/baseline.php
@@ -79,6 +79,7 @@
         'src/features/verbum-comments/class-verbum-comments.php' => ['PhanImpossibleTypeComparison', 'PhanNoopNew', 'PhanParamTooMany', 'PhanTypeMismatchArgumentProbablyReal', 'PhanUndeclaredFunction'],
         'src/features/wpcom-endpoints/class-wpcom-rest-api-v2-endpoint-launchpad.php' => ['PhanPluginDuplicateConditionalNullCoalescing'],
         'src/features/wpcom-endpoints/class-wpcom-rest-api-v2-endpoint-site-migration-migrate-guru-key.php' => ['PhanUndeclaredClassMethod'],
+        'src/features/wpcom-endpoints/class-wpcom-rest-api-v2-endpoint-site-migration-wpcom-migration-key.php' => ['PhanUndeclaredClassMethod'],
         'tests/lib/functions-wordpress.php' => ['PhanRedefineFunction'],
         'tests/php/features/block-patterns/class-wpcom-block-patterns-from-api-test.php' => ['PhanDeprecatedFunction'],
         'tests/php/features/coming-soon/class-coming-soon-test.php' => ['PhanTypeMismatchArgument', 'PhanTypeMismatchArgumentProbablyReal'],
diff --git a/projects/packages/jetpack-mu-wpcom/changelog/add-wpcom-key-endpoint b/projects/packages/jetpack-mu-wpcom/changelog/add-wpcom-key-endpoint
new file mode 100644
index 0000000000000..e92c25acdebd4
--- /dev/null
+++ b/projects/packages/jetpack-mu-wpcom/changelog/add-wpcom-key-endpoint
@@ -0,0 +1,4 @@
+Significance: minor
+Type: added
+
+Add new wpcom-migration-key endpoint.
diff --git a/projects/packages/jetpack-mu-wpcom/src/features/wpcom-endpoints/class-wpcom-rest-api-v2-endpoint-site-migration-wpcom-migration-key.php b/projects/packages/jetpack-mu-wpcom/src/features/wpcom-endpoints/class-wpcom-rest-api-v2-endpoint-site-migration-wpcom-migration-key.php
new file mode 100644
index 0000000000000..955e839d2da66
--- /dev/null
+++ b/projects/packages/jetpack-mu-wpcom/src/features/wpcom-endpoints/class-wpcom-rest-api-v2-endpoint-site-migration-wpcom-migration-key.php
@@ -0,0 +1,109 @@
+<?php
+/**
+ * Allow us to access the Migrate Guru site migration key via API.
+ *
+ * @package automattic/jetpack
+ */
+
+/**
+ * WARNING: This file is distributed verbatim in Jetpack.
+ * There should be nothing WordPress.com specific in this file.
+ *
+ * @hide-in-jetpack
+ */
+class WPCOM_REST_API_V2_Endpoint_Site_Migration_WPCOM_Migration_Key extends WP_REST_Controller {
+	/**
+	 * Option name that tracks wether the key has been read or not.
+	 * The only possible value for the option is 'read'.
+	 *
+	 * @var string
+	 */
+	protected $key_is_read_option_name = 'wpcom_site_migration_wpcom_migration_key_read';
+
+	/**
+	 * Class constructor
+	 */
+	public function __construct() {
+		$this->namespace = 'wpcom/v2';
+		$this->rest_base = 'atomic-migration-status/wpcom-migration-key';
+
+		add_action( 'rest_api_init', array( $this, 'register_routes' ) );
+	}
+
+	/**
+	 * Register our routes.
+	 */
+	public function register_routes() {
+		register_rest_route(
+			$this->namespace,
+			$this->rest_base,
+			array(
+				array(
+					'methods'             => WP_REST_Server::READABLE,
+					'callback'            => array( $this, 'get_data' ),
+					'permission_callback' => array( $this, 'can_access' ),
+				),
+			)
+		);
+	}
+
+	/**
+	 * Permission callback for the REST route.
+	 *
+	 * @return boolean
+	 */
+	public function can_access() {
+		if ( ! class_exists( 'Automattic\Jetpack\Status\Host' ) ) {
+			return false;
+		}
+
+		if ( ! ( new Automattic\Jetpack\Status\Host() )->is_woa_site() ) {
+			return false;
+		}
+
+		if ( ! current_user_can( 'manage_options' ) ) {
+			return false;
+		}
+
+		if ( ! is_plugin_active( 'wpcom-migration/wpcom_migration.php' ) ) {
+			return false;
+		}
+
+		if ( ! class_exists( 'WPCOMWPSettings' ) || ! class_exists( 'WPCOMInfo' ) ) {
+			return false;
+		}
+
+		if ( 'read' === get_option( $this->key_is_read_option_name, false ) ) {
+			return false;
+		}
+
+		return true;
+	}
+
+	/**
+	 * Returns the migration key.
+	 *
+	 * @return string
+	 */
+	private function get_migration_key() {
+		$wpcom_migration_settings = new WPCOMWPSettings();
+		$wpcom_migration_info     = new WPCOMInfo( $wpcom_migration_settings );
+
+		update_option( $this->key_is_read_option_name, 'read' );
+
+		return $wpcom_migration_info->getConnectionKey();
+	}
+
+	/**
+	 * Returns migration key.
+	 *
+	 * @return array Associative array with `migration_key`.
+	 */
+	public function get_data() {
+		return array(
+			'migration_key' => $this->get_migration_key(),
+		);
+	}
+}
+
+wpcom_rest_api_v2_load_plugin( 'WPCOM_REST_API_V2_Endpoint_Site_Migration_WPCOM_Migration_Key' );