diff --git a/specification/communication/data-plane/Chat/preview/2023-07-01-preview/communicationserviceschat.json b/specification/communication/data-plane/Chat/preview/2023-07-01-preview/communicationserviceschat.json
index fca6a903568d..7ac2b708e4e6 100644
--- a/specification/communication/data-plane/Chat/preview/2023-07-01-preview/communicationserviceschat.json
+++ b/specification/communication/data-plane/Chat/preview/2023-07-01-preview/communicationserviceschat.json
@@ -1354,6 +1354,13 @@
           "description": "Time from which the chat history is shared with the participant. The timestamp is in RFC3339 format: `yyyy-MM-ddTHH:mm:ssZ`.",
           "type": "string",
           "example": "2020-10-30T10:50:50Z"
+        },
+        "metadata": {
+          "description": "Contextual metadata for the chat participant. The metadata consists of name/value pairs. The total size of all metadata pairs can be up to 1KB in size.",
+          "type": "object",
+          "additionalProperties": {
+            "type": "string"
+          }
         }
       }
     },
@@ -1618,6 +1625,13 @@
         },
         "retentionPolicy": {
           "$ref": "#/definitions/ChatRetentionPolicy"
+        },
+        "metadata": {
+          "description": "Contextual metadata for the thread. The metadata consists of name/value pairs. The total size of all metadata pairs can be up to 1KB in size.",
+          "type": "object",
+          "additionalProperties": {
+            "type": "string"
+          }
         }
       }
     },
@@ -1658,6 +1672,13 @@
         },
         "retentionPolicy": {
           "$ref": "#/definitions/ChatRetentionPolicy"
+        },
+        "metadata": {
+          "description": "Contextual metadata for the thread. The metadata consists of name/value pairs. The total size of all metadata pairs can be up to 1KB in size.",
+          "type": "object",
+          "additionalProperties": {
+            "type": "string"
+          }
         }
       }
     },
@@ -1743,6 +1764,13 @@
           "description": "Chat thread topic.",
           "type": "string",
           "example": "Lunch Thread"
+        },
+        "metadata": {
+          "description": "Contextual metadata for the thread. The metadata consists of name/value pairs. The total size of all metadata pairs can be up to 1KB in size.",
+          "type": "object",
+          "additionalProperties": {
+            "type": "string"
+          }
         }
       }
     },