diff --git a/apps/sharebymail/lib/Capabilities.php b/apps/sharebymail/lib/Capabilities.php
index 39d7172bb76a9..8be0ca380cf77 100644
--- a/apps/sharebymail/lib/Capabilities.php
+++ b/apps/sharebymail/lib/Capabilities.php
@@ -45,6 +45,27 @@ public function __construct(IManager $manager,
 		$this->settingsManager = $settingsManager;
 	}
 
+	/**
+	 * @return array{
+	 *     files_sharing: array{
+	 *         sharebymail: array{
+	 *             enabled: bool,
+	 *             send_password_by_mail: bool,
+	 *             upload_files_drop: array{
+	 *                 enabled: bool,
+	 *             },
+	 *             password: array{
+	 *                 enabled: bool,
+	 *                 enforced: bool,
+	 *             },
+	 *             expire_date: array{
+	 *                 enabled: bool,
+	 *                 enforced: bool,
+	 *             },
+	 *         }
+	 *     }
+	 * }
+	 */
 	public function getCapabilities(): array {
 		return [
 			'files_sharing' =>
diff --git a/apps/sharebymail/openapi.json b/apps/sharebymail/openapi.json
new file mode 100644
index 0000000000000..517b8d8bdbaa0
--- /dev/null
+++ b/apps/sharebymail/openapi.json
@@ -0,0 +1,102 @@
+{
+    "openapi": "3.0.3",
+    "info": {
+        "title": "sharebymail",
+        "version": "0.0.1",
+        "description": "Share provider which allows you to share files by mail",
+        "license": {
+            "name": "agpl"
+        }
+    },
+    "components": {
+        "securitySchemes": {
+            "basic_auth": {
+                "type": "http",
+                "scheme": "basic"
+            },
+            "bearer_auth": {
+                "type": "http",
+                "scheme": "bearer"
+            }
+        },
+        "schemas": {
+            "Capabilities": {
+                "type": "object",
+                "required": [
+                    "files_sharing"
+                ],
+                "properties": {
+                    "files_sharing": {
+                        "type": "object",
+                        "required": [
+                            "sharebymail"
+                        ],
+                        "properties": {
+                            "sharebymail": {
+                                "type": "object",
+                                "required": [
+                                    "enabled",
+                                    "send_password_by_mail",
+                                    "upload_files_drop",
+                                    "password",
+                                    "expire_date"
+                                ],
+                                "properties": {
+                                    "enabled": {
+                                        "type": "boolean"
+                                    },
+                                    "send_password_by_mail": {
+                                        "type": "boolean"
+                                    },
+                                    "upload_files_drop": {
+                                        "type": "object",
+                                        "required": [
+                                            "enabled"
+                                        ],
+                                        "properties": {
+                                            "enabled": {
+                                                "type": "boolean"
+                                            }
+                                        }
+                                    },
+                                    "password": {
+                                        "type": "object",
+                                        "required": [
+                                            "enabled",
+                                            "enforced"
+                                        ],
+                                        "properties": {
+                                            "enabled": {
+                                                "type": "boolean"
+                                            },
+                                            "enforced": {
+                                                "type": "boolean"
+                                            }
+                                        }
+                                    },
+                                    "expire_date": {
+                                        "type": "object",
+                                        "required": [
+                                            "enabled",
+                                            "enforced"
+                                        ],
+                                        "properties": {
+                                            "enabled": {
+                                                "type": "boolean"
+                                            },
+                                            "enforced": {
+                                                "type": "boolean"
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    },
+    "paths": [],
+    "tags": []
+}
\ No newline at end of file