diff --git a/extensions/synology-chat/src/channel.test-mocks.ts b/extensions/synology-chat/src/channel.test-mocks.ts
index e743859ea4f..5d103291bdc 100644
--- a/extensions/synology-chat/src/channel.test-mocks.ts
+++ b/extensions/synology-chat/src/channel.test-mocks.ts
@@ -75,7 +75,7 @@ vi.mock("openclaw/plugin-sdk/webhook-ingress", async () => {
 vi.mock("./client.js", () => ({
   sendMessage: vi.fn().mockResolvedValue(true),
   sendFileUrl: vi.fn().mockResolvedValue(true),
-  resolveChatUserId: vi.fn().mockResolvedValue(undefined),
+  resolveLegacyWebhookNameToChatUserId: vi.fn().mockResolvedValue(undefined),
 }));
 
 vi.mock("./runtime.js", () => ({
diff --git a/extensions/synology-chat/src/client.test.ts b/extensions/synology-chat/src/client.test.ts
index 2ae24f42904..d977b08b05f 100644
--- a/extensions/synology-chat/src/client.test.ts
+++ b/extensions/synology-chat/src/client.test.ts
@@ -15,7 +15,8 @@ vi.mock("node:http", () => {
 });
 
 // Import after mocks are set up
-const { sendMessage, sendFileUrl, fetchChatUsers, resolveChatUserId } = await import("./client.js");
+const { sendMessage, sendFileUrl, fetchChatUsers, resolveLegacyWebhookNameToChatUserId } =
+  await import("./client.js");
 const https = await import("node:https");
 let fakeNowMs = 1_700_000_000_000;
 
@@ -109,7 +110,7 @@ describe("sendFileUrl", () => {
   });
 });
 
-// Helper to mock the user_list API response for fetchChatUsers / resolveChatUserId
+// Helper to mock the user_list API response for fetchChatUsers / resolveLegacyWebhookNameToChatUserId
 function mockUserListResponse(
   users: Array<{ user_id: number; username: string; nickname: string }>,
 ) {
@@ -146,7 +147,7 @@ function mockUserListResponseImpl(
   httpsGet.mockImplementation(impl);
 }
 
-describe("resolveChatUserId", () => {
+describe("resolveLegacyWebhookNameToChatUserId", () => {
   const baseUrl =
     "https://nas.example.com/webapi/entry.cgi?api=SYNO.Chat.External&method=chatbot&version=2&token=%22test%22";
   const baseUrl2 =
@@ -169,7 +170,7 @@ describe("resolveChatUserId", () => {
       { user_id: 4, username: "jmn67", nickname: "jmn" },
       { user_id: 7, username: "she67", nickname: "sarah" },
     ]);
-    const result = await resolveChatUserId(baseUrl, "jmn");
+    const result = await resolveLegacyWebhookNameToChatUserId(baseUrl, "jmn");
     expect(result).toBe(4);
   });
 
@@ -181,7 +182,7 @@ describe("resolveChatUserId", () => {
     // Advance time to invalidate cache
     fakeNowMs += 10 * 60 * 1000;
     vi.setSystemTime(fakeNowMs);
-    const result = await resolveChatUserId(baseUrl, "jmn67");
+    const result = await resolveLegacyWebhookNameToChatUserId(baseUrl, "jmn67");
     expect(result).toBe(4);
   });
 
@@ -189,7 +190,7 @@ describe("resolveChatUserId", () => {
     mockUserListResponse([{ user_id: 4, username: "JMN67", nickname: "JMN" }]);
     fakeNowMs += 10 * 60 * 1000;
     vi.setSystemTime(fakeNowMs);
-    const result = await resolveChatUserId(baseUrl, "jmn");
+    const result = await resolveLegacyWebhookNameToChatUserId(baseUrl, "jmn");
     expect(result).toBe(4);
   });
 
@@ -197,7 +198,7 @@ describe("resolveChatUserId", () => {
     mockUserListResponse([{ user_id: 4, username: "jmn67", nickname: "jmn" }]);
     fakeNowMs += 10 * 60 * 1000;
     vi.setSystemTime(fakeNowMs);
-    const result = await resolveChatUserId(baseUrl, "unknown_user");
+    const result = await resolveLegacyWebhookNameToChatUserId(baseUrl, "unknown_user");
     expect(result).toBeUndefined();
   });
 
@@ -205,7 +206,7 @@ describe("resolveChatUserId", () => {
     mockUserListResponse([]);
     fakeNowMs += 10 * 60 * 1000;
     vi.setSystemTime(fakeNowMs);
-    await resolveChatUserId(baseUrl, "anyone");
+    await resolveLegacyWebhookNameToChatUserId(baseUrl, "anyone");
     const httpsGet = vi.mocked((https as any).get);
     expect(httpsGet).toHaveBeenCalledWith(
       expect.stringContaining("method=user_list"),
@@ -218,8 +219,8 @@ describe("resolveChatUserId", () => {
     mockUserListResponseOnce([{ user_id: 4, username: "jmn67", nickname: "jmn" }]);
     mockUserListResponseOnce([{ user_id: 9, username: "jmn67", nickname: "jmn" }]);
 
-    const result1 = await resolveChatUserId(baseUrl, "jmn");
-    const result2 = await resolveChatUserId(baseUrl2, "jmn");
+    const result1 = await resolveLegacyWebhookNameToChatUserId(baseUrl, "jmn");
+    const result2 = await resolveLegacyWebhookNameToChatUserId(baseUrl2, "jmn");
 
     expect(result1).toBe(4);
     expect(result2).toBe(9);
diff --git a/extensions/synology-chat/src/client.ts b/extensions/synology-chat/src/client.ts
index d66f1b720f4..03af80b3765 100644
--- a/extensions/synology-chat/src/client.ts
+++ b/extensions/synology-chat/src/client.ts
@@ -173,25 +173,25 @@ export async function fetchChatUsers(
 }
 
 /**
- * Resolve a webhook username to the correct Chat API user_id.
+ * Resolve a mutable webhook username/nickname to the correct Chat API user_id.
  *
  * Synology Chat outgoing webhooks send a user_id that may NOT match the
  * Chat-internal user_id needed by the chatbot API (method=chatbot).
  * The webhook's "username" field corresponds to the Chat user's "nickname".
  *
  * @param incomingUrl - Bot incoming webhook URL (used to derive user_list URL)
- * @param webhookUsername - The username from the outgoing webhook payload
+ * @param mutableWebhookUsername - The username from the outgoing webhook payload
  * @param allowInsecureSsl - Skip TLS verification
  * @returns The correct Chat user_id, or undefined if not found
  */
-export async function resolveChatUserId(
+export async function resolveLegacyWebhookNameToChatUserId(
   incomingUrl: string,
-  webhookUsername: string,
+  mutableWebhookUsername: string,
   allowInsecureSsl = true,
   log?: { warn: (...args: unknown[]) => void },
 ): Promise<number | undefined> {
   const users = await fetchChatUsers(incomingUrl, allowInsecureSsl, log);
-  const lower = webhookUsername.toLowerCase();
+  const lower = mutableWebhookUsername.toLowerCase();
 
   // Match by nickname first (webhook "username" field = Chat "nickname")
   const byNickname = users.find((u) => u.nickname.toLowerCase() === lower);
diff --git a/extensions/synology-chat/src/webhook-handler.test.ts b/extensions/synology-chat/src/webhook-handler.test.ts
index d7d8123403b..7946a870d6f 100644
--- a/extensions/synology-chat/src/webhook-handler.test.ts
+++ b/extensions/synology-chat/src/webhook-handler.test.ts
@@ -1,5 +1,5 @@
 import { describe, it, expect, vi, beforeEach } from "vitest";
-import { resolveChatUserId, sendMessage } from "./client.js";
+import { resolveLegacyWebhookNameToChatUserId, sendMessage } from "./client.js";
 import { makeFormBody, makeReq, makeRes, makeStalledReq } from "./test-http-utils.js";
 import type { ResolvedSynologyChatAccount } from "./types.js";
 import type { WebhookHandlerDeps } from "./webhook-handler.js";
@@ -8,10 +8,10 @@ import {
   createWebhookHandler,
 } from "./webhook-handler.js";
 
-// Mock sendMessage and resolveChatUserId to prevent real HTTP calls
+// Mock sendMessage and resolveLegacyWebhookNameToChatUserId to prevent real HTTP calls
 vi.mock("./client.js", () => ({
   sendMessage: vi.fn().mockResolvedValue(true),
-  resolveChatUserId: vi.fn().mockResolvedValue(undefined),
+  resolveLegacyWebhookNameToChatUserId: vi.fn().mockResolvedValue(undefined),
 }));
 
 function makeAccount(
@@ -342,7 +342,7 @@ describe("createWebhookHandler", () => {
     await handler(req, res);
 
     expect(res._status).toBe(204);
-    expect(resolveChatUserId).not.toHaveBeenCalled();
+    expect(resolveLegacyWebhookNameToChatUserId).not.toHaveBeenCalled();
     expect(deliver).toHaveBeenCalledWith(
       expect.objectContaining({
         from: "123",
@@ -358,7 +358,7 @@ describe("createWebhookHandler", () => {
   });
 
   it("only resolves reply recipient by username when break-glass mode is enabled", async () => {
-    vi.mocked(resolveChatUserId).mockResolvedValueOnce(456);
+    vi.mocked(resolveLegacyWebhookNameToChatUserId).mockResolvedValueOnce(456);
     const deliver = vi.fn().mockResolvedValue("Bot reply");
     const handler = createWebhookHandler({
       account: makeAccount({
@@ -374,7 +374,7 @@ describe("createWebhookHandler", () => {
     await handler(req, res);
 
     expect(res._status).toBe(204);
-    expect(resolveChatUserId).toHaveBeenCalledWith(
+    expect(resolveLegacyWebhookNameToChatUserId).toHaveBeenCalledWith(
       "https://nas.example.com/incoming",
       "testuser",
       true,
@@ -395,7 +395,7 @@ describe("createWebhookHandler", () => {
   });
 
   it("falls back to payload.user_id when break-glass resolution does not find a match", async () => {
-    vi.mocked(resolveChatUserId).mockResolvedValueOnce(undefined);
+    vi.mocked(resolveLegacyWebhookNameToChatUserId).mockResolvedValueOnce(undefined);
     const deliver = vi.fn().mockResolvedValue("Bot reply");
     const handler = createWebhookHandler({
       account: makeAccount({
@@ -411,7 +411,7 @@ describe("createWebhookHandler", () => {
     await handler(req, res);
 
     expect(res._status).toBe(204);
-    expect(resolveChatUserId).toHaveBeenCalledWith(
+    expect(resolveLegacyWebhookNameToChatUserId).toHaveBeenCalledWith(
       "https://nas.example.com/incoming",
       "testuser",
       true,
diff --git a/extensions/synology-chat/src/webhook-handler.ts b/extensions/synology-chat/src/webhook-handler.ts
index aab77c34bd2..ed1a2db123a 100644
--- a/extensions/synology-chat/src/webhook-handler.ts
+++ b/extensions/synology-chat/src/webhook-handler.ts
@@ -10,7 +10,7 @@ import {
   readRequestBodyWithLimit,
   requestBodyErrorToText,
 } from "openclaw/plugin-sdk/webhook-ingress";
-import { sendMessage, resolveChatUserId } from "./client.js";
+import { sendMessage, resolveLegacyWebhookNameToChatUserId } from "./client.js";
 import { validateToken, authorizeUserForDm, sanitizeInput, RateLimiter } from "./security.js";
 import type { SynologyWebhookPayload, ResolvedSynologyChatAccount } from "./types.js";
 
@@ -369,7 +369,7 @@ async function parseAndAuthorizeSynologyWebhook(params: {
   };
 }
 
-async function resolveSynologyReplyUserId(params: {
+async function resolveSynologyDeliveryUserId(params: {
   account: ResolvedSynologyChatAccount;
   payload: SynologyWebhookPayload;
   log?: WebhookHandlerDeps["log"];
@@ -378,14 +378,14 @@ async function resolveSynologyReplyUserId(params: {
     return params.payload.user_id;
   }
 
-  const chatUserId = await resolveChatUserId(
+  const resolvedChatApiUserId = await resolveLegacyWebhookNameToChatUserId(
     params.account.incomingUrl,
     params.payload.username,
     params.account.allowInsecureSsl,
     params.log,
   );
-  if (chatUserId !== undefined) {
-    return String(chatUserId);
+  if (resolvedChatApiUserId !== undefined) {
+    return String(resolvedChatApiUserId);
   }
   params.log?.warn(
     `Could not resolve Chat API user_id for "${params.payload.username}" — falling back to webhook user_id ${params.payload.user_id}. Reply delivery may fail.`,
@@ -399,9 +399,10 @@ async function processAuthorizedSynologyWebhook(params: {
   log?: WebhookHandlerDeps["log"];
   message: AuthorizedSynologyWebhook;
 }): Promise<void> {
-  let replyUserId = params.message.payload.user_id;
+  const authorizedWebhookUserId = params.message.payload.user_id;
+  let deliveryUserId = authorizedWebhookUserId;
   try {
-    replyUserId = await resolveSynologyReplyUserId({
+    deliveryUserId = await resolveSynologyDeliveryUserId({
       account: params.account,
       payload: params.message.payload,
       log: params.log,
@@ -409,13 +410,13 @@ async function processAuthorizedSynologyWebhook(params: {
 
     const deliverPromise = params.deliver({
       body: params.message.body,
-      from: params.message.payload.user_id,
+      from: authorizedWebhookUserId,
       senderName: params.message.payload.username,
       provider: "synology-chat",
       chatType: "direct",
       accountId: params.account.accountId,
       commandAuthorized: params.message.commandAuthorized,
-      chatUserId: replyUserId,
+      chatUserId: deliveryUserId,
     });
     const timeoutPromise = new Promise<null>((_, reject) =>
       setTimeout(() => reject(new Error("Agent response timeout (120s)")), 120_000),
@@ -428,12 +429,12 @@ async function processAuthorizedSynologyWebhook(params: {
     await sendMessage(
       params.account.incomingUrl,
       reply,
-      replyUserId,
+      deliveryUserId,
       params.account.allowInsecureSsl,
     );
     const replyPreview = reply.length > 100 ? `${reply.slice(0, 100)}...` : reply;
     params.log?.info?.(
-      `Reply sent to ${params.message.payload.username} (${replyUserId}): ${replyPreview}`,
+      `Reply sent to ${params.message.payload.username} (${deliveryUserId}): ${replyPreview}`,
     );
   } catch (err) {
     const errMsg = err instanceof Error ? `${err.message}\n${err.stack}` : String(err);
@@ -443,7 +444,7 @@ async function processAuthorizedSynologyWebhook(params: {
     await sendMessage(
       params.account.incomingUrl,
       "Sorry, an error occurred while processing your message.",
-      replyUserId,
+      deliveryUserId,
       params.account.allowInsecureSsl,
     );
   }