diff --git a/extensions/irc/src/accounts.test.ts b/extensions/irc/src/accounts.test.ts
index 1d8ab275af0..676ead48181 100644
--- a/extensions/irc/src/accounts.test.ts
+++ b/extensions/irc/src/accounts.test.ts
@@ -152,4 +152,33 @@ describe("resolveIrcAccount", () => {
     expect(account.passwordSource).toBe("none");
     fs.rmSync(dir, { recursive: true, force: true });
   });
+
+  it("preserves shared NickServ config when an account overrides one NickServ field", () => {
+    const account = resolveIrcAccount({
+      cfg: asConfig({
+        channels: {
+          irc: {
+            host: "irc.example.com",
+            nick: "claw",
+            nickserv: {
+              service: "NickServ",
+            },
+            accounts: {
+              work: {
+                nickserv: {
+                  registerEmail: "work@example.com",
+                },
+              },
+            },
+          },
+        },
+      }),
+      accountId: "work",
+    });
+
+    expect(account.config.nickserv).toEqual({
+      service: "NickServ",
+      registerEmail: "work@example.com",
+    });
+  });
 });
diff --git a/extensions/irc/src/accounts.ts b/extensions/irc/src/accounts.ts
index d33290d0310..71630eb6158 100644
--- a/extensions/irc/src/accounts.ts
+++ b/extensions/irc/src/accounts.ts
@@ -1,6 +1,6 @@
-import { createAccountListHelpers, mergeAccountConfig } from "openclaw/plugin-sdk/account-helpers";
+import { createAccountListHelpers } from "openclaw/plugin-sdk/account-helpers";
 import { DEFAULT_ACCOUNT_ID, normalizeAccountId } from "openclaw/plugin-sdk/account-id";
-import { resolveNormalizedAccountEntry } from "openclaw/plugin-sdk/account-resolution";
+import { resolveMergedAccountConfig } from "openclaw/plugin-sdk/account-resolution";
 import { parseOptionalDelimitedEntries } from "openclaw/plugin-sdk/core";
 import { tryReadSecretFileSync } from "openclaw/plugin-sdk/infra-runtime";
 import { normalizeResolvedSecretInputString } from "openclaw/plugin-sdk/secret-input";
@@ -46,29 +46,15 @@ const { listAccountIds: listIrcAccountIds, resolveDefaultAccountId: resolveDefau
   createAccountListHelpers("irc", { normalizeAccountId });
 export { listIrcAccountIds, resolveDefaultIrcAccountId };
 
-function resolveAccountConfig(cfg: CoreConfig, accountId: string): IrcAccountConfig | undefined {
-  return resolveNormalizedAccountEntry(
-    cfg.channels?.irc?.accounts as Record<string, IrcAccountConfig> | undefined,
-    accountId,
-    normalizeAccountId,
-  );
-}
-
 function mergeIrcAccountConfig(cfg: CoreConfig, accountId: string): IrcAccountConfig {
-  const account = resolveAccountConfig(cfg, accountId) ?? {};
-  const merged: IrcAccountConfig = mergeAccountConfig<IrcAccountConfig>({
+  return resolveMergedAccountConfig<IrcAccountConfig>({
     channelConfig: cfg.channels?.irc as IrcAccountConfig | undefined,
-    accountConfig: account,
+    accounts: cfg.channels?.irc?.accounts as Record<string, Partial<IrcAccountConfig>> | undefined,
+    accountId,
     omitKeys: ["defaultAccount"],
+    normalizeAccountId,
+    nestedObjectKeys: ["nickserv"],
   });
-  const baseNickServ = (cfg.channels?.irc as IrcAccountConfig | undefined)?.nickserv;
-  if (baseNickServ || account.nickserv) {
-    merged.nickserv = {
-      ...baseNickServ,
-      ...account.nickserv,
-    };
-  }
-  return merged;
 }
 
 function resolvePassword(accountId: string, merged: IrcAccountConfig) {
diff --git a/extensions/matrix/src/matrix/accounts.test.ts b/extensions/matrix/src/matrix/accounts.test.ts
index 9b098f47b87..c004da93d82 100644
--- a/extensions/matrix/src/matrix/accounts.test.ts
+++ b/extensions/matrix/src/matrix/accounts.test.ts
@@ -267,4 +267,47 @@ describe("resolveMatrixAccount", () => {
       "@ops:example.org",
     ]);
   });
+
+  it("preserves shared nested dm and actions config when an account overrides one field", () => {
+    const account = resolveMatrixAccount({
+      cfg: {
+        channels: {
+          matrix: {
+            homeserver: "https://matrix.example.org",
+            accessToken: "main-token",
+            dm: {
+              enabled: true,
+              policy: "pairing",
+            },
+            actions: {
+              reactions: true,
+              messages: true,
+            },
+            accounts: {
+              ops: {
+                accessToken: "ops-token",
+                dm: {
+                  allowFrom: ["@ops:example.org"],
+                },
+                actions: {
+                  messages: false,
+                },
+              },
+            },
+          },
+        },
+      },
+      accountId: "ops",
+    });
+
+    expect(account.config.dm).toEqual({
+      enabled: true,
+      policy: "pairing",
+      allowFrom: ["@ops:example.org"],
+    });
+    expect(account.config.actions).toEqual({
+      reactions: true,
+      messages: false,
+    });
+  });
 });
diff --git a/extensions/matrix/src/matrix/accounts.ts b/extensions/matrix/src/matrix/accounts.ts
index 8e0fdaa5a5a..e63b0402a61 100644
--- a/extensions/matrix/src/matrix/accounts.ts
+++ b/extensions/matrix/src/matrix/accounts.ts
@@ -1,3 +1,4 @@
+import { resolveMergedAccountConfig } from "openclaw/plugin-sdk/account-resolution";
 import {
   resolveConfiguredMatrixAccountIds,
   resolveMatrixDefaultOrOnlyAccountId,
@@ -8,26 +9,10 @@ import {
   normalizeAccountId,
 } from "../runtime-api.js";
 import type { CoreConfig, MatrixConfig } from "../types.js";
-import { findMatrixAccountConfig, resolveMatrixBaseConfig } from "./account-config.js";
+import { resolveMatrixBaseConfig } from "./account-config.js";
 import { resolveMatrixConfigForAccount } from "./client.js";
 import { credentialsMatchConfig, loadMatrixCredentials } from "./credentials-read.js";
 
-/** Merge account config with top-level defaults, preserving nested objects. */
-function mergeAccountConfig(base: MatrixConfig, account: MatrixConfig): MatrixConfig {
-  const merged = { ...base, ...account };
-  // Deep-merge known nested objects so partial overrides inherit base fields
-  for (const key of ["dm", "actions"] as const) {
-    const b = base[key];
-    const o = account[key];
-    if (typeof b === "object" && b != null && typeof o === "object" && o != null) {
-      (merged as Record<string, unknown>)[key] = { ...b, ...o };
-    }
-  }
-  // Don't propagate the accounts map into the merged per-account config
-  delete (merged as Record<string, unknown>).accounts;
-  return merged;
-}
-
 export type ResolvedMatrixAccount = {
   accountId: string;
   enabled: boolean;
@@ -145,12 +130,13 @@ export function resolveMatrixAccountConfig(params: {
   accountId?: string | null;
 }): MatrixConfig {
   const accountId = normalizeAccountId(params.accountId);
-  const matrixBase = resolveMatrixBaseConfig(params.cfg);
-  const accountConfig = findMatrixAccountConfig(params.cfg, accountId);
-  if (!accountConfig) {
-    return matrixBase;
-  }
-  // Merge account-specific config with top-level defaults so settings like
-  // groupPolicy and blockStreaming inherit when not overridden.
-  return mergeAccountConfig(matrixBase, accountConfig);
+  return resolveMergedAccountConfig<MatrixConfig>({
+    channelConfig: resolveMatrixBaseConfig(params.cfg),
+    accounts: params.cfg.channels?.matrix?.accounts as
+      | Record<string, Partial<MatrixConfig>>
+      | undefined,
+    accountId,
+    normalizeAccountId,
+    nestedObjectKeys: ["dm", "actions"],
+  });
 }
diff --git a/extensions/mattermost/src/mattermost/accounts.test.ts b/extensions/mattermost/src/mattermost/accounts.test.ts
index 097836b8a68..00f18cc6864 100644
--- a/extensions/mattermost/src/mattermost/accounts.test.ts
+++ b/extensions/mattermost/src/mattermost/accounts.test.ts
@@ -87,4 +87,31 @@ describe("resolveMattermostReplyToMode", () => {
     const account = resolveMattermostAccount({ cfg: {}, accountId: "default" });
     expect(resolveMattermostReplyToMode(account, "channel")).toBe("off");
   });
+
+  it("preserves shared commands config when an account overrides one commands field", () => {
+    const account = resolveMattermostAccount({
+      cfg: {
+        channels: {
+          mattermost: {
+            commands: {
+              native: true,
+            },
+            accounts: {
+              work: {
+                commands: {
+                  callbackPath: "/hooks/work",
+                },
+              },
+            },
+          },
+        },
+      },
+      accountId: "work",
+    });
+
+    expect(account.config.commands).toEqual({
+      native: true,
+      callbackPath: "/hooks/work",
+    });
+  });
 });
diff --git a/extensions/mattermost/src/mattermost/accounts.ts b/extensions/mattermost/src/mattermost/accounts.ts
index c919eeeaa8f..c4b97c8f650 100644
--- a/extensions/mattermost/src/mattermost/accounts.ts
+++ b/extensions/mattermost/src/mattermost/accounts.ts
@@ -1,8 +1,5 @@
 import { DEFAULT_ACCOUNT_ID, normalizeAccountId } from "openclaw/plugin-sdk/account-id";
-import {
-  resolveAccountEntry,
-  resolveMergedAccountConfig,
-} from "openclaw/plugin-sdk/account-resolution";
+import { resolveMergedAccountConfig } from "openclaw/plugin-sdk/account-resolution";
 import { createAccountListHelpers, type OpenClawConfig } from "../runtime-api.js";
 import { normalizeResolvedSecretInputString, normalizeSecretInputString } from "../secret-input.js";
 import type {
@@ -39,39 +36,19 @@ const {
 } = createAccountListHelpers("mattermost");
 export { listMattermostAccountIds, resolveDefaultMattermostAccountId };
 
-function resolveAccountConfig(
-  cfg: OpenClawConfig,
-  accountId: string,
-): MattermostAccountConfig | undefined {
-  return resolveAccountEntry(cfg.channels?.mattermost?.accounts, accountId);
-}
-
 function mergeMattermostAccountConfig(
   cfg: OpenClawConfig,
   accountId: string,
 ): MattermostAccountConfig {
-  const account = resolveAccountConfig(cfg, accountId) ?? {};
-  const merged = resolveMergedAccountConfig<MattermostAccountConfig>({
+  return resolveMergedAccountConfig<MattermostAccountConfig>({
     channelConfig: cfg.channels?.mattermost as MattermostAccountConfig | undefined,
     accounts: cfg.channels?.mattermost?.accounts as
       | Record<string, Partial<MattermostAccountConfig>>
       | undefined,
     accountId,
     omitKeys: ["defaultAccount"],
+    nestedObjectKeys: ["commands"],
   });
-
-  // Shallow merging is fine for most keys, but `commands` should be merged
-  // so that account-specific overrides (callbackPath/callbackUrl) do not
-  // accidentally reset global settings like `native: true`.
-  const mergedCommands = {
-    ...((cfg.channels?.mattermost as MattermostAccountConfig | undefined)?.commands ?? {}),
-    ...(account.commands ?? {}),
-  };
-  if (Object.keys(mergedCommands).length > 0) {
-    merged.commands = mergedCommands;
-  }
-
-  return merged;
 }
 
 function resolveMattermostRequireMention(config: MattermostAccountConfig): boolean | undefined {
diff --git a/extensions/nextcloud-talk/src/accounts.ts b/extensions/nextcloud-talk/src/accounts.ts
index 27e3178c84c..f3721ebf719 100644
--- a/extensions/nextcloud-talk/src/accounts.ts
+++ b/extensions/nextcloud-talk/src/accounts.ts
@@ -1,7 +1,4 @@
-import {
-  mergeAccountConfig,
-  resolveNormalizedAccountEntry,
-} from "openclaw/plugin-sdk/account-resolution";
+import { resolveMergedAccountConfig } from "openclaw/plugin-sdk/account-resolution";
 import { tryReadSecretFileSync } from "openclaw/plugin-sdk/infra-runtime";
 import {
   createAccountListHelpers,
@@ -47,27 +44,18 @@ export function listNextcloudTalkAccountIds(cfg: CoreConfig): string[] {
   return ids;
 }
 
-function resolveAccountConfig(
-  cfg: CoreConfig,
-  accountId: string,
-): NextcloudTalkAccountConfig | undefined {
-  return resolveNormalizedAccountEntry(
-    cfg.channels?.["nextcloud-talk"]?.accounts as
-      | Record<string, NextcloudTalkAccountConfig>
-      | undefined,
-    accountId,
-    normalizeAccountId,
-  );
-}
-
 function mergeNextcloudTalkAccountConfig(
   cfg: CoreConfig,
   accountId: string,
 ): NextcloudTalkAccountConfig {
-  return mergeAccountConfig<NextcloudTalkAccountConfig>({
+  return resolveMergedAccountConfig<NextcloudTalkAccountConfig>({
     channelConfig: cfg.channels?.["nextcloud-talk"] as NextcloudTalkAccountConfig | undefined,
-    accountConfig: resolveAccountConfig(cfg, accountId),
+    accounts: cfg.channels?.["nextcloud-talk"]?.accounts as
+      | Record<string, Partial<NextcloudTalkAccountConfig>>
+      | undefined,
+    accountId,
     omitKeys: ["defaultAccount"],
+    normalizeAccountId,
   });
 }
 
diff --git a/src/channels/plugins/account-helpers.test.ts b/src/channels/plugins/account-helpers.test.ts
index 8ee5805a93d..02d9d26c503 100644
--- a/src/channels/plugins/account-helpers.test.ts
+++ b/src/channels/plugins/account-helpers.test.ts
@@ -239,6 +239,31 @@ describe("mergeAccountConfig", () => {
       name: "Work",
     });
   });
+
+  it("deep-merges selected nested object keys", () => {
+    const merged = mergeAccountConfig<{
+      commands?: { native?: boolean; callbackPath?: string };
+    }>({
+      channelConfig: {
+        commands: {
+          native: true,
+        },
+      },
+      accountConfig: {
+        commands: {
+          callbackPath: "/work",
+        },
+      },
+      nestedObjectKeys: ["commands"],
+    });
+
+    expect(merged).toEqual({
+      commands: {
+        native: true,
+        callbackPath: "/work",
+      },
+    });
+  });
 });
 
 describe("resolveMergedAccountConfig", () => {
@@ -286,4 +311,32 @@ describe("resolveMergedAccountConfig", () => {
       name: "Router",
     });
   });
+
+  it("deep-merges selected nested object keys after resolving the account", () => {
+    const merged = resolveMergedAccountConfig<{
+      nickserv?: { service?: string; registerEmail?: string };
+    }>({
+      channelConfig: {
+        nickserv: {
+          service: "NickServ",
+        },
+      },
+      accounts: {
+        work: {
+          nickserv: {
+            registerEmail: "work@example.com",
+          },
+        },
+      },
+      accountId: "work",
+      nestedObjectKeys: ["nickserv"],
+    });
+
+    expect(merged).toEqual({
+      nickserv: {
+        service: "NickServ",
+        registerEmail: "work@example.com",
+      },
+    });
+  });
 });
diff --git a/src/channels/plugins/account-helpers.ts b/src/channels/plugins/account-helpers.ts
index fde09b2ca37..a137f0baf4f 100644
--- a/src/channels/plugins/account-helpers.ts
+++ b/src/channels/plugins/account-helpers.ts
@@ -123,6 +123,7 @@ export function mergeAccountConfig<TConfig extends Record<string, unknown>>(para
   channelConfig: TConfig | undefined;
   accountConfig: Partial<TConfig> | undefined;
   omitKeys?: string[];
+  nestedObjectKeys?: string[];
 }): TConfig {
   const omitKeys = new Set(["accounts", ...(params.omitKeys ?? [])]);
   const base = Object.fromEntries(
@@ -130,10 +131,28 @@ export function mergeAccountConfig<TConfig extends Record<string, unknown>>(para
       ([key]) => !omitKeys.has(key),
     ),
   ) as TConfig;
-  return {
+  const merged = {
     ...base,
     ...params.accountConfig,
   };
+  for (const key of params.nestedObjectKeys ?? []) {
+    const baseValue = base[key as keyof TConfig];
+    const accountValue = params.accountConfig?.[key as keyof TConfig];
+    if (
+      typeof baseValue === "object" &&
+      baseValue != null &&
+      !Array.isArray(baseValue) &&
+      typeof accountValue === "object" &&
+      accountValue != null &&
+      !Array.isArray(accountValue)
+    ) {
+      (merged as Record<string, unknown>)[key] = {
+        ...(baseValue as Record<string, unknown>),
+        ...(accountValue as Record<string, unknown>),
+      };
+    }
+  }
+  return merged;
 }
 
 export function resolveMergedAccountConfig<TConfig extends Record<string, unknown>>(params: {
@@ -142,6 +161,7 @@ export function resolveMergedAccountConfig<TConfig extends Record<string, unknow
   accountId: string;
   omitKeys?: string[];
   normalizeAccountId?: (accountId: string) => string;
+  nestedObjectKeys?: string[];
 }): TConfig {
   const accountConfig = params.normalizeAccountId
     ? resolveNormalizedAccountEntry(params.accounts, params.accountId, params.normalizeAccountId)
@@ -150,5 +170,6 @@ export function resolveMergedAccountConfig<TConfig extends Record<string, unknow
     channelConfig: params.channelConfig,
     accountConfig,
     omitKeys: params.omitKeys,
+    nestedObjectKeys: params.nestedObjectKeys,
   });
 }