diff --git a/discovery/youtube-v3.json b/discovery/youtube-v3.json
index e1dd1c02017..4df550f3063 100644
--- a/discovery/youtube-v3.json
+++ b/discovery/youtube-v3.json
@@ -3765,7 +3765,7 @@
       }
     }
   },
-  "revision": "20210706",
+  "revision": "20210828",
   "rootUrl": "https://youtube.googleapis.com/",
   "schemas": {
     "AbuseReport": {
@@ -8132,6 +8132,25 @@
       },
       "type": "object"
     },
+    "LiveChatMemberMilestoneChatDetails": {
+      "id": "LiveChatMemberMilestoneChatDetails",
+      "properties": {
+        "memberLevelName": {
+          "description": "The name of the Level at which the viever is a member. The Level names are defined by the YouTube channel offering the Membership. In some situations this field isn't filled.",
+          "type": "string"
+        },
+        "memberMonth": {
+          "description": "The total amount of months (rounded up) the viewer has been a member that granted them this Member Milestone Chat. This is the same number of months as is being displayed to YouTube users.",
+          "format": "uint32",
+          "type": "integer"
+        },
+        "userComment": {
+          "description": "The comment added by the member to this Member Milestone Chat. This field is empty for messages without a comment from the member.",
+          "type": "string"
+        }
+      },
+      "type": "object"
+    },
     "LiveChatMessage": {
       "description": "A *liveChatMessage* resource represents a chat message in a YouTube Live Chat.",
       "id": "LiveChatMessage",
@@ -8266,10 +8285,11 @@
       "type": "object"
     },
     "LiveChatMessageSnippet": {
+      "description": "Next ID: 31",
       "id": "LiveChatMessageSnippet",
       "properties": {
         "authorChannelId": {
-          "description": "The ID of the user that authored this message, this field is not always filled. textMessageEvent - the user that wrote the message fanFundingEvent - the user that funded the broadcast newSponsorEvent - the user that just became a sponsor messageDeletedEvent - the moderator that took the action messageRetractedEvent - the author that retracted their message userBannedEvent - the moderator that took the action superChatEvent - the user that made the purchase",
+          "description": "The ID of the user that authored this message, this field is not always filled. textMessageEvent - the user that wrote the message fanFundingEvent - the user that funded the broadcast newSponsorEvent - the user that just became a sponsor memberMilestoneChatEvent - the member that sent the message messageDeletedEvent - the moderator that took the action messageRetractedEvent - the author that retracted their message userBannedEvent - the moderator that took the action superChatEvent - the user that made the purchase superStickerEvent - the user that made the purchase",
           "type": "string"
         },
         "displayMessage": {
@@ -8287,12 +8307,20 @@
         "liveChatId": {
           "type": "string"
         },
+        "memberMilestoneChatDetails": {
+          "$ref": "LiveChatMemberMilestoneChatDetails",
+          "description": "Details about the Member Milestone Chat event, this is only set if the type is 'memberMilestoneChatEvent'."
+        },
         "messageDeletedDetails": {
           "$ref": "LiveChatMessageDeletedDetails"
         },
         "messageRetractedDetails": {
           "$ref": "LiveChatMessageRetractedDetails"
         },
+        "newSponsorDetails": {
+          "$ref": "LiveChatNewSponsorDetails",
+          "description": "Details about the New Member Announcement event, this is only set if the type is 'newSponsorEvent'. Please note that \"member\" is the new term for \"sponsor\"."
+        },
         "publishedAt": {
           "description": "The date and time when the message was orignally published.",
           "format": "date-time",
@@ -8321,6 +8349,7 @@
             "sponsorOnlyModeStartedEvent",
             "sponsorOnlyModeEndedEvent",
             "newSponsorEvent",
+            "memberMilestoneChatEvent",
             "messageDeletedEvent",
             "messageRetractedEvent",
             "userBannedEvent",
@@ -8340,6 +8369,7 @@
             "",
             "",
             "",
+            "",
             ""
           ],
           "type": "string"
@@ -8433,6 +8463,20 @@
       },
       "type": "object"
     },
+    "LiveChatNewSponsorDetails": {
+      "id": "LiveChatNewSponsorDetails",
+      "properties": {
+        "isUpgrade": {
+          "description": "If the viewer just had upgraded from a lower level. For viewers that were not members at the time of purchase, this field is false.",
+          "type": "boolean"
+        },
+        "memberLevelName": {
+          "description": "The name of the Level that the viewer just had joined. The Level names are defined by the YouTube channel offering the Membership. In some situations this field isn't filled.",
+          "type": "string"
+        }
+      },
+      "type": "object"
+    },
     "LiveChatSuperChatDetails": {
       "id": "LiveChatSuperChatDetails",
       "properties": {
diff --git a/src/apis/youtube/v3.ts b/src/apis/youtube/v3.ts
index 14cc35c5195..0edaf77e04e 100644
--- a/src/apis/youtube/v3.ts
+++ b/src/apis/youtube/v3.ts
@@ -2245,6 +2245,20 @@ export namespace youtube_v3 {
      */
     userComment?: string | null;
   }
+  export interface Schema$LiveChatMemberMilestoneChatDetails {
+    /**
+     * The name of the Level at which the viever is a member. The Level names are defined by the YouTube channel offering the Membership. In some situations this field isn't filled.
+     */
+    memberLevelName?: string | null;
+    /**
+     * The total amount of months (rounded up) the viewer has been a member that granted them this Member Milestone Chat. This is the same number of months as is being displayed to YouTube users.
+     */
+    memberMonth?: number | null;
+    /**
+     * The comment added by the member to this Member Milestone Chat. This field is empty for messages without a comment from the member.
+     */
+    userComment?: string | null;
+  }
   /**
    * A *liveChatMessage* resource represents a chat message in a YouTube Live Chat.
    */
@@ -2343,9 +2357,12 @@ export namespace youtube_v3 {
   export interface Schema$LiveChatMessageRetractedDetails {
     retractedMessageId?: string | null;
   }
+  /**
+   * Next ID: 31
+   */
   export interface Schema$LiveChatMessageSnippet {
     /**
-     * The ID of the user that authored this message, this field is not always filled. textMessageEvent - the user that wrote the message fanFundingEvent - the user that funded the broadcast newSponsorEvent - the user that just became a sponsor messageDeletedEvent - the moderator that took the action messageRetractedEvent - the author that retracted their message userBannedEvent - the moderator that took the action superChatEvent - the user that made the purchase
+     * The ID of the user that authored this message, this field is not always filled. textMessageEvent - the user that wrote the message fanFundingEvent - the user that funded the broadcast newSponsorEvent - the user that just became a sponsor memberMilestoneChatEvent - the member that sent the message messageDeletedEvent - the moderator that took the action messageRetractedEvent - the author that retracted their message userBannedEvent - the moderator that took the action superChatEvent - the user that made the purchase superStickerEvent - the user that made the purchase
      */
     authorChannelId?: string | null;
     /**
@@ -2361,8 +2378,16 @@ export namespace youtube_v3 {
      */
     hasDisplayContent?: boolean | null;
     liveChatId?: string | null;
+    /**
+     * Details about the Member Milestone Chat event, this is only set if the type is 'memberMilestoneChatEvent'.
+     */
+    memberMilestoneChatDetails?: Schema$LiveChatMemberMilestoneChatDetails;
     messageDeletedDetails?: Schema$LiveChatMessageDeletedDetails;
     messageRetractedDetails?: Schema$LiveChatMessageRetractedDetails;
+    /**
+     * Details about the New Member Announcement event, this is only set if the type is 'newSponsorEvent'. Please note that "member" is the new term for "sponsor".
+     */
+    newSponsorDetails?: Schema$LiveChatNewSponsorDetails;
     /**
      * The date and time when the message was orignally published.
      */
@@ -2451,6 +2476,16 @@ export namespace youtube_v3 {
      */
     moderatorDetails?: Schema$ChannelProfileDetails;
   }
+  export interface Schema$LiveChatNewSponsorDetails {
+    /**
+     * If the viewer just had upgraded from a lower level. For viewers that were not members at the time of purchase, this field is false.
+     */
+    isUpgrade?: boolean | null;
+    /**
+     * The name of the Level that the viewer just had joined. The Level names are defined by the YouTube channel offering the Membership. In some situations this field isn't filled.
+     */
+    memberLevelName?: string | null;
+  }
   export interface Schema$LiveChatSuperChatDetails {
     /**
      * A rendered string that displays the fund amount and currency to the user.