diff --git a/lib/ResponseDefinitions.php b/lib/ResponseDefinitions.php
index 4189222dad3..263f3deb244 100644
--- a/lib/ResponseDefinitions.php
+++ b/lib/ResponseDefinitions.php
@@ -67,6 +67,32 @@
  *     statusMessage: ?string,
  * }
  *
+ * @psalm-type TalkRichObjectParameter = array{
+ *     type: string,
+ *     id: string,
+ *     name: string,
+ *     server?: string,
+ *     link?: string,
+ *     'call-type'?: 'one2one'|'group'|'public',
+ *     'icon-url'?: string,
+ *     'message-id'?: string,
+ *     boardname?: string,
+ *     stackname?: string,
+ *     size?: string,
+ *     path?: string,
+ *     mimetype?: string,
+ *     'preview-available'?: 'yes'|'no',
+ *     mtime?: string,
+ *     latitude?: string,
+ *     longitude?: string,
+ *     description?: string,
+ *     thumb?: string,
+ *     website?: string,
+ *     visibility?: '0'|'1',
+ *     assignable?: '0'|'1',
+ *     conversation?: string,
+ * }
+ *
  * @psalm-type TalkChatMessage = array{
  *     actorDisplayName: string,
  *     actorId: string,
@@ -77,7 +103,7 @@
  *     isReplyable: bool,
  *     markdown: bool,
  *     message: string,
- *     messageParameters: array<string, array<string, mixed>>,
+ *     messageParameters: array<string, TalkRichObjectParameter>,
  *     messageType: string,
  *     reactions: array<string, integer>|\stdClass,
  *     referenceId: string,
@@ -97,7 +123,7 @@
  *     actorType: string,
  *     expirationTimestamp: int,
  *     message: string,
- *     messageParameters: array<string, array<string, mixed>>,
+ *     messageParameters: array<string, TalkRichObjectParameter>,
  *     messageType: string,
  *     systemMessage: string,
  * }
diff --git a/openapi-backend-sipbridge.json b/openapi-backend-sipbridge.json
index 109f038f0be..6af28b900b5 100644
--- a/openapi-backend-sipbridge.json
+++ b/openapi-backend-sipbridge.json
@@ -263,10 +263,7 @@
                     "messageParameters": {
                         "type": "object",
                         "additionalProperties": {
-                            "type": "object",
-                            "additionalProperties": {
-                                "type": "object"
-                            }
+                            "$ref": "#/components/schemas/RichObjectParameter"
                         }
                     },
                     "messageType": {
@@ -353,6 +350,102 @@
                     }
                 ]
             },
+            "RichObjectParameter": {
+                "type": "object",
+                "required": [
+                    "type",
+                    "id",
+                    "name"
+                ],
+                "properties": {
+                    "type": {
+                        "type": "string"
+                    },
+                    "id": {
+                        "type": "string"
+                    },
+                    "name": {
+                        "type": "string"
+                    },
+                    "server": {
+                        "type": "string"
+                    },
+                    "link": {
+                        "type": "string"
+                    },
+                    "call-type": {
+                        "type": "string",
+                        "enum": [
+                            "one2one",
+                            "group",
+                            "public"
+                        ]
+                    },
+                    "icon-url": {
+                        "type": "string"
+                    },
+                    "message-id": {
+                        "type": "string"
+                    },
+                    "boardname": {
+                        "type": "string"
+                    },
+                    "stackname": {
+                        "type": "string"
+                    },
+                    "size": {
+                        "type": "string"
+                    },
+                    "path": {
+                        "type": "string"
+                    },
+                    "mimetype": {
+                        "type": "string"
+                    },
+                    "preview-available": {
+                        "type": "string",
+                        "enum": [
+                            "yes",
+                            "no"
+                        ]
+                    },
+                    "mtime": {
+                        "type": "string"
+                    },
+                    "latitude": {
+                        "type": "string"
+                    },
+                    "longitude": {
+                        "type": "string"
+                    },
+                    "description": {
+                        "type": "string"
+                    },
+                    "thumb": {
+                        "type": "string"
+                    },
+                    "website": {
+                        "type": "string"
+                    },
+                    "visibility": {
+                        "type": "string",
+                        "enum": [
+                            "0",
+                            "1"
+                        ]
+                    },
+                    "assignable": {
+                        "type": "string",
+                        "enum": [
+                            "0",
+                            "1"
+                        ]
+                    },
+                    "conversation": {
+                        "type": "string"
+                    }
+                }
+            },
             "Room": {
                 "type": "object",
                 "required": [
@@ -655,10 +748,7 @@
                     "messageParameters": {
                         "type": "object",
                         "additionalProperties": {
-                            "type": "object",
-                            "additionalProperties": {
-                                "type": "object"
-                            }
+                            "$ref": "#/components/schemas/RichObjectParameter"
                         }
                     },
                     "messageType": {
diff --git a/openapi-federation.json b/openapi-federation.json
index 7336aaa20f1..73c52570625 100644
--- a/openapi-federation.json
+++ b/openapi-federation.json
@@ -263,10 +263,7 @@
                     "messageParameters": {
                         "type": "object",
                         "additionalProperties": {
-                            "type": "object",
-                            "additionalProperties": {
-                                "type": "object"
-                            }
+                            "$ref": "#/components/schemas/RichObjectParameter"
                         }
                     },
                     "messageType": {
@@ -407,6 +404,102 @@
                     }
                 ]
             },
+            "RichObjectParameter": {
+                "type": "object",
+                "required": [
+                    "type",
+                    "id",
+                    "name"
+                ],
+                "properties": {
+                    "type": {
+                        "type": "string"
+                    },
+                    "id": {
+                        "type": "string"
+                    },
+                    "name": {
+                        "type": "string"
+                    },
+                    "server": {
+                        "type": "string"
+                    },
+                    "link": {
+                        "type": "string"
+                    },
+                    "call-type": {
+                        "type": "string",
+                        "enum": [
+                            "one2one",
+                            "group",
+                            "public"
+                        ]
+                    },
+                    "icon-url": {
+                        "type": "string"
+                    },
+                    "message-id": {
+                        "type": "string"
+                    },
+                    "boardname": {
+                        "type": "string"
+                    },
+                    "stackname": {
+                        "type": "string"
+                    },
+                    "size": {
+                        "type": "string"
+                    },
+                    "path": {
+                        "type": "string"
+                    },
+                    "mimetype": {
+                        "type": "string"
+                    },
+                    "preview-available": {
+                        "type": "string",
+                        "enum": [
+                            "yes",
+                            "no"
+                        ]
+                    },
+                    "mtime": {
+                        "type": "string"
+                    },
+                    "latitude": {
+                        "type": "string"
+                    },
+                    "longitude": {
+                        "type": "string"
+                    },
+                    "description": {
+                        "type": "string"
+                    },
+                    "thumb": {
+                        "type": "string"
+                    },
+                    "website": {
+                        "type": "string"
+                    },
+                    "visibility": {
+                        "type": "string",
+                        "enum": [
+                            "0",
+                            "1"
+                        ]
+                    },
+                    "assignable": {
+                        "type": "string",
+                        "enum": [
+                            "0",
+                            "1"
+                        ]
+                    },
+                    "conversation": {
+                        "type": "string"
+                    }
+                }
+            },
             "Room": {
                 "type": "object",
                 "required": [
@@ -709,10 +802,7 @@
                     "messageParameters": {
                         "type": "object",
                         "additionalProperties": {
-                            "type": "object",
-                            "additionalProperties": {
-                                "type": "object"
-                            }
+                            "$ref": "#/components/schemas/RichObjectParameter"
                         }
                     },
                     "messageType": {
diff --git a/openapi-full.json b/openapi-full.json
index cef8274f87c..cec04ca5716 100644
--- a/openapi-full.json
+++ b/openapi-full.json
@@ -424,10 +424,7 @@
                     "messageParameters": {
                         "type": "object",
                         "additionalProperties": {
-                            "type": "object",
-                            "additionalProperties": {
-                                "type": "object"
-                            }
+                            "$ref": "#/components/schemas/RichObjectParameter"
                         }
                     },
                     "messageType": {
@@ -872,6 +869,102 @@
                     }
                 }
             },
+            "RichObjectParameter": {
+                "type": "object",
+                "required": [
+                    "type",
+                    "id",
+                    "name"
+                ],
+                "properties": {
+                    "type": {
+                        "type": "string"
+                    },
+                    "id": {
+                        "type": "string"
+                    },
+                    "name": {
+                        "type": "string"
+                    },
+                    "server": {
+                        "type": "string"
+                    },
+                    "link": {
+                        "type": "string"
+                    },
+                    "call-type": {
+                        "type": "string",
+                        "enum": [
+                            "one2one",
+                            "group",
+                            "public"
+                        ]
+                    },
+                    "icon-url": {
+                        "type": "string"
+                    },
+                    "message-id": {
+                        "type": "string"
+                    },
+                    "boardname": {
+                        "type": "string"
+                    },
+                    "stackname": {
+                        "type": "string"
+                    },
+                    "size": {
+                        "type": "string"
+                    },
+                    "path": {
+                        "type": "string"
+                    },
+                    "mimetype": {
+                        "type": "string"
+                    },
+                    "preview-available": {
+                        "type": "string",
+                        "enum": [
+                            "yes",
+                            "no"
+                        ]
+                    },
+                    "mtime": {
+                        "type": "string"
+                    },
+                    "latitude": {
+                        "type": "string"
+                    },
+                    "longitude": {
+                        "type": "string"
+                    },
+                    "description": {
+                        "type": "string"
+                    },
+                    "thumb": {
+                        "type": "string"
+                    },
+                    "website": {
+                        "type": "string"
+                    },
+                    "visibility": {
+                        "type": "string",
+                        "enum": [
+                            "0",
+                            "1"
+                        ]
+                    },
+                    "assignable": {
+                        "type": "string",
+                        "enum": [
+                            "0",
+                            "1"
+                        ]
+                    },
+                    "conversation": {
+                        "type": "string"
+                    }
+                }
+            },
             "Room": {
                 "type": "object",
                 "required": [
@@ -1174,10 +1267,7 @@
                     "messageParameters": {
                         "type": "object",
                         "additionalProperties": {
-                            "type": "object",
-                            "additionalProperties": {
-                                "type": "object"
-                            }
+                            "$ref": "#/components/schemas/RichObjectParameter"
                         }
                     },
                     "messageType": {
diff --git a/openapi.json b/openapi.json
index 9f7862926f8..93fb28bc7bd 100644
--- a/openapi.json
+++ b/openapi.json
@@ -365,10 +365,7 @@
                     "messageParameters": {
                         "type": "object",
                         "additionalProperties": {
-                            "type": "object",
-                            "additionalProperties": {
-                                "type": "object"
-                            }
+                            "$ref": "#/components/schemas/RichObjectParameter"
                         }
                     },
                     "messageType": {
@@ -759,6 +756,102 @@
                     }
                 }
             },
+            "RichObjectParameter": {
+                "type": "object",
+                "required": [
+                    "type",
+                    "id",
+                    "name"
+                ],
+                "properties": {
+                    "type": {
+                        "type": "string"
+                    },
+                    "id": {
+                        "type": "string"
+                    },
+                    "name": {
+                        "type": "string"
+                    },
+                    "server": {
+                        "type": "string"
+                    },
+                    "link": {
+                        "type": "string"
+                    },
+                    "call-type": {
+                        "type": "string",
+                        "enum": [
+                            "one2one",
+                            "group",
+                            "public"
+                        ]
+                    },
+                    "icon-url": {
+                        "type": "string"
+                    },
+                    "message-id": {
+                        "type": "string"
+                    },
+                    "boardname": {
+                        "type": "string"
+                    },
+                    "stackname": {
+                        "type": "string"
+                    },
+                    "size": {
+                        "type": "string"
+                    },
+                    "path": {
+                        "type": "string"
+                    },
+                    "mimetype": {
+                        "type": "string"
+                    },
+                    "preview-available": {
+                        "type": "string",
+                        "enum": [
+                            "yes",
+                            "no"
+                        ]
+                    },
+                    "mtime": {
+                        "type": "string"
+                    },
+                    "latitude": {
+                        "type": "string"
+                    },
+                    "longitude": {
+                        "type": "string"
+                    },
+                    "description": {
+                        "type": "string"
+                    },
+                    "thumb": {
+                        "type": "string"
+                    },
+                    "website": {
+                        "type": "string"
+                    },
+                    "visibility": {
+                        "type": "string",
+                        "enum": [
+                            "0",
+                            "1"
+                        ]
+                    },
+                    "assignable": {
+                        "type": "string",
+                        "enum": [
+                            "0",
+                            "1"
+                        ]
+                    },
+                    "conversation": {
+                        "type": "string"
+                    }
+                }
+            },
             "Room": {
                 "type": "object",
                 "required": [
@@ -1061,10 +1154,7 @@
                     "messageParameters": {
                         "type": "object",
                         "additionalProperties": {
-                            "type": "object",
-                            "additionalProperties": {
-                                "type": "object"
-                            }
+                            "$ref": "#/components/schemas/RichObjectParameter"
                         }
                     },
                     "messageType": {
diff --git a/src/types/openapi/openapi-backend-sipbridge.ts b/src/types/openapi/openapi-backend-sipbridge.ts
index ab8a5879f80..026c7805dc1 100644
--- a/src/types/openapi/openapi-backend-sipbridge.ts
+++ b/src/types/openapi/openapi-backend-sipbridge.ts
@@ -104,9 +104,7 @@ export type components = {
       markdown: boolean;
       message: string;
       messageParameters: {
-        [key: string]: {
-          [key: string]: Record<string, never>;
-        };
+        [key: string]: components["schemas"]["RichObjectParameter"];
       };
       messageType: string;
       reactions: {
@@ -134,6 +132,35 @@ export type components = {
     PublicCapabilities: OneOf<[{
       spreed: components["schemas"]["Capabilities"];
     }, unknown[]]>;
+    RichObjectParameter: {
+      type: string;
+      id: string;
+      name: string;
+      server?: string;
+      link?: string;
+      /** @enum {string} */
+      "call-type"?: "one2one" | "group" | "public";
+      "icon-url"?: string;
+      "message-id"?: string;
+      boardname?: string;
+      stackname?: string;
+      size?: string;
+      path?: string;
+      mimetype?: string;
+      /** @enum {string} */
+      "preview-available"?: "yes" | "no";
+      mtime?: string;
+      latitude?: string;
+      longitude?: string;
+      description?: string;
+      thumb?: string;
+      website?: string;
+      /** @enum {string} */
+      visibility?: "0" | "1";
+      /** @enum {string} */
+      assignable?: "0" | "1";
+      conversation?: string;
+    };
     Room: {
       actorId: string;
       actorType: string;
@@ -228,9 +255,7 @@ export type components = {
       expirationTimestamp: number;
       message: string;
       messageParameters: {
-        [key: string]: {
-          [key: string]: Record<string, never>;
-        };
+        [key: string]: components["schemas"]["RichObjectParameter"];
       };
       messageType: string;
       systemMessage: string;
diff --git a/src/types/openapi/openapi-federation.ts b/src/types/openapi/openapi-federation.ts
index 912d7ee5cdf..ea46a31bb16 100644
--- a/src/types/openapi/openapi-federation.ts
+++ b/src/types/openapi/openapi-federation.ts
@@ -111,9 +111,7 @@ export type components = {
       markdown: boolean;
       message: string;
       messageParameters: {
-        [key: string]: {
-          [key: string]: Record<string, never>;
-        };
+        [key: string]: components["schemas"]["RichObjectParameter"];
       };
       messageType: string;
       reactions: {
@@ -157,6 +155,35 @@ export type components = {
     PublicCapabilities: OneOf<[{
       spreed: components["schemas"]["Capabilities"];
     }, unknown[]]>;
+    RichObjectParameter: {
+      type: string;
+      id: string;
+      name: string;
+      server?: string;
+      link?: string;
+      /** @enum {string} */
+      "call-type"?: "one2one" | "group" | "public";
+      "icon-url"?: string;
+      "message-id"?: string;
+      boardname?: string;
+      stackname?: string;
+      size?: string;
+      path?: string;
+      mimetype?: string;
+      /** @enum {string} */
+      "preview-available"?: "yes" | "no";
+      mtime?: string;
+      latitude?: string;
+      longitude?: string;
+      description?: string;
+      thumb?: string;
+      website?: string;
+      /** @enum {string} */
+      visibility?: "0" | "1";
+      /** @enum {string} */
+      assignable?: "0" | "1";
+      conversation?: string;
+    };
     Room: {
       actorId: string;
       actorType: string;
@@ -251,9 +278,7 @@ export type components = {
       expirationTimestamp: number;
       message: string;
       messageParameters: {
-        [key: string]: {
-          [key: string]: Record<string, never>;
-        };
+        [key: string]: components["schemas"]["RichObjectParameter"];
       };
       messageType: string;
       systemMessage: string;
diff --git a/src/types/openapi/openapi-full.ts b/src/types/openapi/openapi-full.ts
index 02fcb75e689..69a13e521a4 100644
--- a/src/types/openapi/openapi-full.ts
+++ b/src/types/openapi/openapi-full.ts
@@ -627,9 +627,7 @@ export type components = {
       markdown: boolean;
       message: string;
       messageParameters: {
-        [key: string]: {
-          [key: string]: Record<string, never>;
-        };
+        [key: string]: components["schemas"]["RichObjectParameter"];
       };
       messageType: string;
       reactions: {
@@ -761,6 +759,35 @@ export type components = {
       /** Format: int64 */
       timestamp: number;
     };
+    RichObjectParameter: {
+      type: string;
+      id: string;
+      name: string;
+      server?: string;
+      link?: string;
+      /** @enum {string} */
+      "call-type"?: "one2one" | "group" | "public";
+      "icon-url"?: string;
+      "message-id"?: string;
+      boardname?: string;
+      stackname?: string;
+      size?: string;
+      path?: string;
+      mimetype?: string;
+      /** @enum {string} */
+      "preview-available"?: "yes" | "no";
+      mtime?: string;
+      latitude?: string;
+      longitude?: string;
+      description?: string;
+      thumb?: string;
+      website?: string;
+      /** @enum {string} */
+      visibility?: "0" | "1";
+      /** @enum {string} */
+      assignable?: "0" | "1";
+      conversation?: string;
+    };
     Room: {
       actorId: string;
       actorType: string;
@@ -855,9 +882,7 @@ export type components = {
       expirationTimestamp: number;
       message: string;
       messageParameters: {
-        [key: string]: {
-          [key: string]: Record<string, never>;
-        };
+        [key: string]: components["schemas"]["RichObjectParameter"];
       };
       messageType: string;
       systemMessage: string;
diff --git a/src/types/openapi/openapi.ts b/src/types/openapi/openapi.ts
index b58d20e7cf0..ace0b2c0586 100644
--- a/src/types/openapi/openapi.ts
+++ b/src/types/openapi/openapi.ts
@@ -474,9 +474,7 @@ export type components = {
       markdown: boolean;
       message: string;
       messageParameters: {
-        [key: string]: {
-          [key: string]: Record<string, never>;
-        };
+        [key: string]: components["schemas"]["RichObjectParameter"];
       };
       messageType: string;
       reactions: {
@@ -592,6 +590,35 @@ export type components = {
       /** Format: int64 */
       timestamp: number;
     };
+    RichObjectParameter: {
+      type: string;
+      id: string;
+      name: string;
+      server?: string;
+      link?: string;
+      /** @enum {string} */
+      "call-type"?: "one2one" | "group" | "public";
+      "icon-url"?: string;
+      "message-id"?: string;
+      boardname?: string;
+      stackname?: string;
+      size?: string;
+      path?: string;
+      mimetype?: string;
+      /** @enum {string} */
+      "preview-available"?: "yes" | "no";
+      mtime?: string;
+      latitude?: string;
+      longitude?: string;
+      description?: string;
+      thumb?: string;
+      website?: string;
+      /** @enum {string} */
+      visibility?: "0" | "1";
+      /** @enum {string} */
+      assignable?: "0" | "1";
+      conversation?: string;
+    };
     Room: {
       actorId: string;
       actorType: string;
@@ -686,9 +713,7 @@ export type components = {
       expirationTimestamp: number;
       message: string;
       messageParameters: {
-        [key: string]: {
-          [key: string]: Record<string, never>;
-        };
+        [key: string]: components["schemas"]["RichObjectParameter"];
       };
       messageType: string;
       systemMessage: string;