diff --git a/.changeset/good-tigers-lie.md b/.changeset/good-tigers-lie.md
new file mode 100644
index 0000000000000..2a9a13b858af4
--- /dev/null
+++ b/.changeset/good-tigers-lie.md
@@ -0,0 +1,6 @@
+---
+'@rocket.chat/rest-typings': minor
+'@rocket.chat/meteor': minor
+---
+
+Migrated chat.syncThreadMessages old Rest Api strucutre to new typed rest (openAPI) structure
diff --git a/apps/meteor/app/api/server/v1/chat.ts b/apps/meteor/app/api/server/v1/chat.ts
index a00d57e46ae72..ce4f72d67407c 100644
--- a/apps/meteor/app/api/server/v1/chat.ts
+++ b/apps/meteor/app/api/server/v1/chat.ts
@@ -21,12 +21,12 @@ import {
 	isChatGetDeletedMessagesProps,
 	isChatSyncThreadsListProps,
 	isChatGetThreadMessagesProps,
-	isChatSyncThreadMessagesProps,
 	isChatGetStarredMessagesProps,
 	isChatGetDiscussionsProps,
 	validateBadRequestErrorResponse,
 	validateUnauthorizedErrorResponse,
 } from '@rocket.chat/rest-typings';
+import type { PaginatedRequest } from '@rocket.chat/rest-typings';
 import { escapeRegExp } from '@rocket.chat/string-helpers';
 import { Meteor } from 'meteor/meteor';
 
@@ -275,6 +275,85 @@ const isChatPinMessageProps = ajv.compile<ChatPinMessage>(ChatPinMessageSchema);
 
 const isChatUnpinMessageProps = ajv.compile<ChatUnpinMessage>(ChatUnpinMessageSchema);
 
+type ChatSyncThreadMessages = PaginatedRequest<{
+	tmid: string;
+	updatedSince: string;
+}>;
+
+const ChatSyncThreadMessagesSchema = {
+	type: 'object',
+	properties: {
+		tmid: {
+			type: 'string',
+			minLength: 1,
+		},
+		updatedSince: {
+			type: 'string',
+			format: 'iso-date-time',
+		},
+		count: {
+			type: 'number',
+			nullable: true,
+		},
+		offset: {
+			type: 'number',
+			nullable: true,
+		},
+		sort: {
+			type: 'string',
+			nullable: true,
+		},
+		query: {
+			type: 'string',
+			nullable: true,
+		},
+		fields: {
+			type: 'string',
+			nullable: true,
+		},
+	},
+	required: ['tmid', 'updatedSince'],
+	additionalProperties: false,
+};
+
+const isChatSyncThreadMessagesLocalProps = ajv.compile<ChatSyncThreadMessages>(ChatSyncThreadMessagesSchema);
+
+const isSyncThreadMessagesResponse = ajv.compile<{
+	messages: {
+		update: IMessage[];
+		remove: IMessage[];
+	};
+}>({
+	type: 'object',
+	properties: {
+		messages: {
+			type: 'object',
+			properties: {
+				update: {
+					type: 'array',
+					items: {
+						$ref: '#/components/schemas/IMessage',
+					},
+				},
+				remove: {
+					type: 'array',
+					items: {
+						$ref: '#/components/schemas/IMessage',
+					},
+				},
+			},
+			required: ['update', 'remove'],
+			additionalProperties: false,
+		},
+		success: {
+			type: 'boolean',
+			enum: [true],
+		},
+	},
+	required: ['messages', 'success'],
+	additionalProperties: false,
+});
+
 const chatEndpoints = API.v1
 	.post(
 		'chat.pinMessage',
@@ -558,6 +637,51 @@ const chatEndpoints = API.v1
 
 			return API.v1.success();
 		},
+	)
+	.get(
+		'chat.syncThreadMessages',
+		{
+			authRequired: true,
+			query: isChatSyncThreadMessagesLocalProps,
+			response: {
+				400: validateBadRequestErrorResponse,
+				401: validateUnauthorizedErrorResponse,
+				200: isSyncThreadMessagesResponse,
+			},
+		},
+		async function action() {
+			const { tmid } = this.queryParams;
+			const { query, fields, sort } = await this.parseJsonQuery();
+			const { updatedSince } = this.queryParams;
+			let updatedSinceDate;
+			if (!settings.get<boolean>('Threads_enabled')) {
+				throw new Meteor.Error('error-not-allowed', 'Threads Disabled');
+			}
+
+			if (isNaN(Date.parse(updatedSince))) {
+				throw new Meteor.Error('error-updatedSince-param-invalid', 'The "updatedSince" query parameter must be a valid date.');
+			} else {
+				updatedSinceDate = new Date(updatedSince);
+			}
+			const thread = await Messages.findOneById(tmid, { projection: { rid: 1 } });
+			if (!thread?.rid) {
+				throw new Meteor.Error('error-invalid-message', 'Invalid Message');
+			}
+			const [user, room] = await Promise.all([
+				Users.findOneById(this.userId, { projection: { _id: 1 } }),
+				Rooms.findOneById(thread.rid, { projection: { ...roomAccessAttributes, t: 1, _id: 1 } }),
+			]);
+
+			if (!room || !user || !(await canAccessRoomAsync(room, user))) {
+				throw new Meteor.Error('error-not-allowed', 'Not Allowed');
+			}
+			return API.v1.success({
+				messages: {
+					update: await Messages.find({ ...query, tmid, _updatedAt: { $gt: updatedSinceDate } }, { projection: fields, sort }).toArray(),
+					remove: await Messages.trashFindDeletedAfter(updatedSinceDate, { ...query, tmid }, { projection: fields, sort }).toArray(),
+				},
+			});
+		},
 	);
 
 API.v1.addRoute(
@@ -918,45 +1042,6 @@ API.v1.addRoute(
 	},
 );
 
-API.v1.addRoute(
-	'chat.syncThreadMessages',
-	{ authRequired: true, validateParams: isChatSyncThreadMessagesProps },
-	{
-		async get() {
-			const { tmid } = this.queryParams;
-			const { query, fields, sort } = await this.parseJsonQuery();
-			const { updatedSince } = this.queryParams;
-			let updatedSinceDate;
-			if (!settings.get<boolean>('Threads_enabled')) {
-				throw new Meteor.Error('error-not-allowed', 'Threads Disabled');
-			}
-
-			if (isNaN(Date.parse(updatedSince))) {
-				throw new Meteor.Error('error-updatedSince-param-invalid', 'The "updatedSince" query parameter must be a valid date.');
-			} else {
-				updatedSinceDate = new Date(updatedSince);
-			}
-			const thread = await Messages.findOneById(tmid, { projection: { rid: 1 } });
-			if (!thread?.rid) {
-				throw new Meteor.Error('error-invalid-message', 'Invalid Message');
-			}
-			// TODO: promise.all? this.user?
-			const user = await Users.findOneById(this.userId, { projection: { _id: 1 } });
-			const room = await Rooms.findOneById(thread.rid, { projection: { ...roomAccessAttributes, t: 1, _id: 1 } });
-
-			if (!room || !user || !(await canAccessRoomAsync(room, user))) {
-				throw new Meteor.Error('error-not-allowed', 'Not Allowed');
-			}
-			return API.v1.success({
-				messages: {
-					update: await Messages.find({ ...query, tmid, _updatedAt: { $gt: updatedSinceDate } }, { projection: fields, sort }).toArray(),
-					remove: await Messages.trashFindDeletedAfter(updatedSinceDate, { ...query, tmid }, { projection: fields, sort }).toArray(),
-				},
-			});
-		},
-	},
-);
-
 API.v1.addRoute(
 	'chat.getMentionedMessages',
 	{ authRequired: true, validateParams: isChatGetMentionedMessagesProps },
diff --git a/apps/meteor/tests/end-to-end/api/chat.ts b/apps/meteor/tests/end-to-end/api/chat.ts
index 7fd725ed5bfbc..2c3c949ec5aaa 100644
--- a/apps/meteor/tests/end-to-end/api/chat.ts
+++ b/apps/meteor/tests/end-to-end/api/chat.ts
@@ -4568,7 +4568,7 @@ describe('Threads', () => {
 					.expect(400)
 					.expect((res) => {
 						expect(res.body).to.have.property('success', false);
-						expect(res.body).to.have.property('errorType', 'invalid-params');
+						expect(res.body).to.have.property('errorType', 'error-invalid-params');
 					})
 					.end(done);
 			});
@@ -4586,7 +4586,7 @@ describe('Threads', () => {
 					.expect(400)
 					.expect((res) => {
 						expect(res.body).to.have.property('success', false);
-						expect(res.body).to.have.property('errorType', 'invalid-params');
+						expect(res.body).to.have.property('errorType', 'error-invalid-params');
 					})
 					.end(done);
 			});
@@ -4605,7 +4605,7 @@ describe('Threads', () => {
 					.expect(400)
 					.expect((res) => {
 						expect(res.body).to.have.property('success', false);
-						expect(res.body).to.have.property('errorType', 'invalid-params');
+						expect(res.body).to.have.property('errorType', 'error-invalid-params');
 					})
 					.end(done);
 			});
diff --git a/packages/rest-typings/src/v1/chat.ts b/packages/rest-typings/src/v1/chat.ts
index f3a6e61f677b0..96fff08072acb 100644
--- a/packages/rest-typings/src/v1/chat.ts
+++ b/packages/rest-typings/src/v1/chat.ts
@@ -638,41 +638,6 @@ const ChatSyncMessagesSchema = {
 
 export const isChatSyncMessagesProps = ajvQuery.compile<ChatSyncMessages>(ChatSyncMessagesSchema);
 
-type ChatSyncThreadMessages = PaginatedRequest<{
-	tmid: string;
-	updatedSince: string;
-}>;
-
-const ChatSyncThreadMessagesSchema = {
-	type: 'object',
-	properties: {
-		tmid: {
-			type: 'string',
-			minLength: 1,
-		},
-		updatedSince: {
-			type: 'string',
-			format: 'iso-date-time',
-		},
-		count: {
-			type: 'number',
-			nullable: true,
-		},
-		offset: {
-			type: 'number',
-			nullable: true,
-		},
-		sort: {
-			type: 'string',
-			nullable: true,
-		},
-	},
-	required: ['tmid', 'updatedSince'],
-	additionalProperties: false,
-};
-
-export const isChatSyncThreadMessagesProps = ajvQuery.compile<ChatSyncThreadMessages>(ChatSyncThreadMessagesSchema);
-
 type ChatGetThreadMessages = PaginatedRequest<{
 	tmid: string;
 }>;
@@ -989,14 +954,6 @@ export type ChatEndpoints = {
 			message: IMessage;
 		};
 	};
-	'/v1/chat.syncThreadMessages': {
-		GET: (params: ChatSyncThreadMessages) => {
-			messages: {
-				update: IMessage[];
-				remove: IMessage[];
-			};
-		};
-	};
 	'/v1/chat.getThreadMessages': {
 		GET: (params: ChatGetThreadMessages) => {
 			messages: IMessage[];