diff --git a/projects/packages/publicize/changelog/update-unify-social-connections-schema b/projects/packages/publicize/changelog/update-unify-social-connections-schema
new file mode 100644
index 0000000000000..feff6a2e9064f
--- /dev/null
+++ b/projects/packages/publicize/changelog/update-unify-social-connections-schema
@@ -0,0 +1,4 @@
+Significance: minor
+Type: changed
+
+Social: Use connections REST endpoint for initial state
diff --git a/projects/packages/publicize/src/class-connections.php b/projects/packages/publicize/src/class-connections.php
new file mode 100644
index 0000000000000..de30d41e264ae
--- /dev/null
+++ b/projects/packages/publicize/src/class-connections.php
@@ -0,0 +1,94 @@
+<?php
+/**
+ * Publicize Connections class.
+ *
+ * @package automattic/jetpack-publicize
+ */
+
+namespace Automattic\Jetpack\Publicize;
+
+use Automattic\Jetpack\Connection;
+use Automattic\Jetpack\Publicize\REST_API\Connections_Controller;
+use Automattic\Jetpack\Status\Host;
+
+/**
+ * Publicize Connections class.
+ */
+class Connections {
+
+	const CONNECTIONS_TRANSIENT = 'jetpack_social_connections_list';
+
+	/**
+	 * Get all connections.
+	 *
+	 * @param array $args Arguments
+	 *                - 'clear_cache': bool Whether to clear the cache.
+	 *                - 'test_connections': bool Whether to run connection tests.
+	 * @return array
+	 */
+	public static function get_all( $args = array() ) {
+
+		$run_tests = $args['test_connections'] ?? false;
+
+		$is_wpcom = ( new Host() )->is_wpcom_simple();
+
+		if ( $is_wpcom ) {
+			$connections = Connections_Controller::get_connections( $run_tests );
+		} else {
+			$connections = self::fetch_and_cache_connections( $run_tests );
+		}
+
+		// Let us add the deprecated fields for now.
+		// TODO: Remove this after https://github.com/Automattic/jetpack/pull/40539 is merged.
+		$connections = self::retain_deprecated_fields( $connections );
+
+		return $connections;
+	}
+
+	/**
+	 * Retain deprecated fields.
+	 *
+	 * @param array $connections Connections.
+	 * @return array
+	 */
+	private static function retain_deprecated_fields( $connections ) {
+		return array_map(
+			function ( $connection ) {
+				$wpcom_user_data = ( new Connection\Manager() )->get_connected_user_data();
+
+				$owns_connection = ! empty( $wpcom_user_data['ID'] ) && $wpcom_user_data['ID'] === $connection['user_id'];
+
+				$connection = array_merge(
+					$connection,
+					array(
+						'external_display' => $connection['display_name'],
+						'can_disconnect'   => current_user_can( 'edit_others_posts' ) || $owns_connection,
+						'label'            => $connection['service_label'],
+					)
+				);
+
+				if ( 'bluesky' === $connection['service_name'] ) {
+					$connection['external_name'] = $connection['external_handle'];
+				}
+
+				return $connection;
+			},
+			$connections
+		);
+	}
+
+	/**
+	 * Fetch connections from the REST API and cache them.
+	 *
+	 * @param bool $run_tests Whether to run connection tests.
+	 *
+	 * @return array
+	 */
+	public static function fetch_and_cache_connections( $run_tests = false ) {
+		$connections = Connections_Controller::get_connections( $run_tests );
+
+		// TODO Implement caching here.
+
+		return $connections;
+	}
+}
diff --git a/projects/packages/publicize/src/class-publicize-base.php b/projects/packages/publicize/src/class-publicize-base.php
index c2e6c044cc5bf..324c233089b25 100644
--- a/projects/packages/publicize/src/class-publicize-base.php
+++ b/projects/packages/publicize/src/class-publicize-base.php
@@ -556,8 +556,8 @@ public function get_profile_link( $service_name, $connection ) {
 	public function get_display_name( $service_name, $connection ) {
 		$cmeta = $this->get_connection_meta( $connection );
 
-		if ( 'mastodon' === $service_name && isset( $cmeta['external_name'] ) ) {
-			return $cmeta['external_name'];
+		if ( 'mastodon' === $service_name && isset( $cmeta['external_display'] ) ) {
+			return $cmeta['external_display'];
 		}
 
 		if ( isset( $cmeta['connection_data']['meta']['display_name'] ) ) {
diff --git a/projects/packages/publicize/src/class-publicize-script-data.php b/projects/packages/publicize/src/class-publicize-script-data.php
index b4e7dded6b62d..63ca3c726944a 100644
--- a/projects/packages/publicize/src/class-publicize-script-data.php
+++ b/projects/packages/publicize/src/class-publicize-script-data.php
@@ -21,8 +21,6 @@
  */
 class Publicize_Script_Data {
 
-	const SERVICES_TRANSIENT = 'jetpack_social_services_list';
-
 	/**
 	 * Get the publicize instance - properly typed
 	 *
@@ -160,8 +158,7 @@ public static function get_store_initial_state() {
 
 		return array(
 			'connectionData' => array(
-				// We do not have this method on WPCOM Publicize class yet.
-				'connections' => ! $is_wpcom ? self::publicize()->get_all_connections_for_user() : array(),
+				'connections' => Connections::get_all(),
 			),
 			'shareStatus'    => $share_status,
 		);
@@ -238,17 +235,24 @@ public static function get_api_paths() {
 
 		$is_simple_site = ( new Host() )->is_wpcom_simple();
 
+		$commom_paths = array(
+			'refreshConnections' => '/wpcom/v2/publicize/connections?test_connections=1',
+		);
+
+		$specific_paths = array();
+
 		if ( $is_simple_site ) {
-			return array(
-				'refreshConnections' => '/wpcom/v2/publicize/connection-test-results',
-				'resharePost'        => '/wpcom/v2/posts/{postId}/publicize',
+
+			$specific_paths = array(
+				'resharePost' => '/wpcom/v2/posts/{postId}/publicize',
+			);
+		} else {
+			$specific_paths = array(
+				'resharePost' => '/jetpack/v4/publicize/{postId}',
 			);
 		}
 
-		return array(
-			'refreshConnections' => '/jetpack/v4/publicize/connections?test_connections=1',
-			'resharePost'        => '/jetpack/v4/publicize/{postId}',
-		);
+		return array_merge( $commom_paths, $specific_paths );
 	}
 
 	/**