diff --git a/surfsense_web/lib/apis/chat-comments-api.service.ts b/surfsense_web/lib/apis/chat-comments-api.service.ts
new file mode 100644
index 000000000..8fa683e1c
--- /dev/null
+++ b/surfsense_web/lib/apis/chat-comments-api.service.ts
@@ -0,0 +1,168 @@
+import {
+	type CreateCommentRequest,
+	type CreateReplyRequest,
+	type DeleteCommentRequest,
+	type GetCommentsRequest,
+	type GetMentionsRequest,
+	type MarkMentionReadRequest,
+	type UpdateCommentRequest,
+	createCommentRequest,
+	createCommentResponse,
+	createReplyRequest,
+	createReplyResponse,
+	deleteCommentRequest,
+	deleteCommentResponse,
+	getCommentsRequest,
+	getCommentsResponse,
+	getMentionsRequest,
+	getMentionsResponse,
+	markAllMentionsReadResponse,
+	markMentionReadRequest,
+	markMentionReadResponse,
+	updateCommentRequest,
+	updateCommentResponse,
+} from "@/contracts/types/chat-comments.types";
+import { ValidationError } from "@/lib/error";
+import { baseApiService } from "./base-api.service";
+
+class ChatCommentsApiService {
+	/**
+	 * Get comments for a message
+	 */
+	getComments = async (request: GetCommentsRequest) => {
+		const parsed = getCommentsRequest.safeParse(request);
+
+		if (!parsed.success) {
+			const errorMessage = parsed.error.issues.map((issue) => issue.message).join(", ");
+			throw new ValidationError(`Invalid request: ${errorMessage}`);
+		}
+
+		return baseApiService.get(
+			`/api/v1/messages/${parsed.data.message_id}/comments`,
+			getCommentsResponse
+		);
+	};
+
+	/**
+	 * Create a top-level comment
+	 */
+	createComment = async (request: CreateCommentRequest) => {
+		const parsed = createCommentRequest.safeParse(request);
+
+		if (!parsed.success) {
+			const errorMessage = parsed.error.issues.map((issue) => issue.message).join(", ");
+			throw new ValidationError(`Invalid request: ${errorMessage}`);
+		}
+
+		return baseApiService.post(
+			`/api/v1/messages/${parsed.data.message_id}/comments`,
+			createCommentResponse,
+			{ body: { content: parsed.data.content } }
+		);
+	};
+
+	/**
+	 * Create a reply to a comment
+	 */
+	createReply = async (request: CreateReplyRequest) => {
+		const parsed = createReplyRequest.safeParse(request);
+
+		if (!parsed.success) {
+			const errorMessage = parsed.error.issues.map((issue) => issue.message).join(", ");
+			throw new ValidationError(`Invalid request: ${errorMessage}`);
+		}
+
+		return baseApiService.post(
+			`/api/v1/comments/${parsed.data.comment_id}/replies`,
+			createReplyResponse,
+			{ body: { content: parsed.data.content } }
+		);
+	};
+
+	/**
+	 * Update a comment
+	 */
+	updateComment = async (request: UpdateCommentRequest) => {
+		const parsed = updateCommentRequest.safeParse(request);
+
+		if (!parsed.success) {
+			const errorMessage = parsed.error.issues.map((issue) => issue.message).join(", ");
+			throw new ValidationError(`Invalid request: ${errorMessage}`);
+		}
+
+		return baseApiService.put(
+			`/api/v1/comments/${parsed.data.comment_id}`,
+			updateCommentResponse,
+			{ body: { content: parsed.data.content } }
+		);
+	};
+
+	/**
+	 * Delete a comment
+	 */
+	deleteComment = async (request: DeleteCommentRequest) => {
+		const parsed = deleteCommentRequest.safeParse(request);
+
+		if (!parsed.success) {
+			const errorMessage = parsed.error.issues.map((issue) => issue.message).join(", ");
+			throw new ValidationError(`Invalid request: ${errorMessage}`);
+		}
+
+		return baseApiService.delete(
+			`/api/v1/comments/${parsed.data.comment_id}`,
+			deleteCommentResponse
+		);
+	};
+
+	/**
+	 * Get mentions for current user
+	 */
+	getMentions = async (request?: GetMentionsRequest) => {
+		const parsed = getMentionsRequest.safeParse(request ?? {});
+
+		if (!parsed.success) {
+			const errorMessage = parsed.error.issues.map((issue) => issue.message).join(", ");
+			throw new ValidationError(`Invalid request: ${errorMessage}`);
+		}
+
+		const params = new URLSearchParams();
+		if (parsed.data.search_space_id !== undefined) {
+			params.set("search_space_id", String(parsed.data.search_space_id));
+		}
+		if (parsed.data.unread_only !== undefined) {
+			params.set("unread_only", String(parsed.data.unread_only));
+		}
+
+		const queryString = params.toString();
+		const url = queryString ? `/api/v1/mentions?${queryString}` : "/api/v1/mentions";
+
+		return baseApiService.get(url, getMentionsResponse);
+	};
+
+	/**
+	 * Mark a mention as read
+	 */
+	markMentionRead = async (request: MarkMentionReadRequest) => {
+		const parsed = markMentionReadRequest.safeParse(request);
+
+		if (!parsed.success) {
+			const errorMessage = parsed.error.issues.map((issue) => issue.message).join(", ");
+			throw new ValidationError(`Invalid request: ${errorMessage}`);
+		}
+
+		return baseApiService.put(
+			`/api/v1/mentions/${parsed.data.mention_id}/read`,
+			markMentionReadResponse
+		);
+	};
+
+	/**
+	 * Mark all mentions as read
+	 */
+	markAllMentionsRead = async () => {
+		return baseApiService.put("/api/v1/mentions/read-all", markAllMentionsReadResponse);
+	};
+}
+
+export const chatCommentsApiService = new ChatCommentsApiService();
+