diff --git a/src/channels/allowlist-match.ts b/src/channels/allowlist-match.ts
index 8c105f1e51b..e65f58e3c6b 100644
--- a/src/channels/allowlist-match.ts
+++ b/src/channels/allowlist-match.ts
@@ -1,3 +1,8 @@
+import {
+  normalizeLowercaseStringOrEmpty,
+  normalizeOptionalLowercaseString,
+} from "../shared/string-coerce.js";
+
 export type AllowlistMatchSource =
   | "wildcard"
   | "id"
@@ -37,7 +42,9 @@ export function compileAllowlist(entries: ReadonlyArray<string>): CompiledAllowl
 
 function compileSimpleAllowlist(entries: ReadonlyArray<string | number>): CompiledAllowlist {
   return compileAllowlist(
-    entries.map((entry) => String(entry).trim().toLowerCase()).filter(Boolean),
+    entries
+      .map((entry) => normalizeOptionalLowercaseString(String(entry)))
+      .filter((entry): entry is string => Boolean(entry)),
   );
 }
 
@@ -98,8 +105,8 @@ export function resolveAllowlistMatchSimple(params: {
     return { allowed: true, matchKey: "*", matchSource: "wildcard" };
   }
 
-  const senderId = params.senderId.toLowerCase();
-  const senderName = params.senderName?.toLowerCase();
+  const senderId = normalizeLowercaseStringOrEmpty(params.senderId);
+  const senderName = normalizeOptionalLowercaseString(params.senderName);
   return resolveAllowlistCandidates({
     compiledAllowlist: allowFrom,
     candidates: [
diff --git a/src/channels/allowlists/resolve-utils.ts b/src/channels/allowlists/resolve-utils.ts
index 84a3da97b5e..ded157d20fd 100644
--- a/src/channels/allowlists/resolve-utils.ts
+++ b/src/channels/allowlists/resolve-utils.ts
@@ -1,5 +1,6 @@
 import { mapAllowFromEntries } from "openclaw/plugin-sdk/channel-config-helpers";
 import type { RuntimeEnv } from "../../runtime.js";
+import { normalizeLowercaseStringOrEmpty } from "../../shared/string-coerce.js";
 import { summarizeStringEntries } from "../../shared/string-sample.js";
 
 export type AllowlistUserResolutionLike = {
@@ -16,7 +17,7 @@ function dedupeAllowlistEntries(entries: string[]): string[] {
     if (!normalized) {
       continue;
     }
-    const key = normalized.toLowerCase();
+    const key = normalizeLowercaseStringOrEmpty(normalized);
     if (seen.has(key)) {
       continue;
     }
diff --git a/src/channels/channel-config.ts b/src/channels/channel-config.ts
index e13ecb96837..fd74617c012 100644
--- a/src/channels/channel-config.ts
+++ b/src/channels/channel-config.ts
@@ -1,3 +1,5 @@
+import { normalizeLowercaseStringOrEmpty } from "../shared/string-coerce.js";
+
 export type ChannelMatchSource = "direct" | "parent" | "wildcard";
 
 export type ChannelEntryMatch<T> = {
@@ -32,9 +34,7 @@ export function resolveChannelMatchConfig<
 }
 
 export function normalizeChannelSlug(value: string): string {
-  return value
-    .trim()
-    .toLowerCase()
+  return normalizeLowercaseStringOrEmpty(value)
     .replace(/^#/, "")
     .replace(/[^a-z0-9]+/g, "-")
     .replace(/^-+|-+$/g, "");
diff --git a/src/channels/conversation-binding-context.ts b/src/channels/conversation-binding-context.ts
index a7289f78ba6..ac5509e287d 100644
--- a/src/channels/conversation-binding-context.ts
+++ b/src/channels/conversation-binding-context.ts
@@ -2,6 +2,7 @@ import type { OpenClawConfig } from "../config/config.js";
 import { resolveConversationIdFromTargets } from "../infra/outbound/conversation-id.js";
 import { getActivePluginChannelRegistry } from "../plugins/runtime.js";
 import {
+  normalizeLowercaseStringOrEmpty,
   normalizeOptionalLowercaseString,
   normalizeOptionalString,
 } from "../shared/string-coerce.js";
@@ -78,7 +79,7 @@ function resolveChannelTargetId(params: {
     return undefined;
   }
 
-  const lower = target.toLowerCase();
+  const lower = normalizeLowercaseStringOrEmpty(target);
   const channelPrefix = `${params.channel}:`;
   if (lower.startsWith(channelPrefix)) {
     return resolveChannelTargetId({
diff --git a/src/channels/native-command-session-targets.ts b/src/channels/native-command-session-targets.ts
index 8d50029843b..5850f769e42 100644
--- a/src/channels/native-command-session-targets.ts
+++ b/src/channels/native-command-session-targets.ts
@@ -1,3 +1,5 @@
+import { normalizeLowercaseStringOrEmpty } from "../shared/string-coerce.js";
+
 export type ResolveNativeCommandSessionTargetsParams = {
   agentId: string;
   sessionPrefix: string;
@@ -13,7 +15,9 @@ export function resolveNativeCommandSessionTargets(
   const rawSessionKey =
     params.boundSessionKey ?? `agent:${params.agentId}:${params.sessionPrefix}:${params.userId}`;
   return {
-    sessionKey: params.lowercaseSessionKey ? rawSessionKey.toLowerCase() : rawSessionKey,
+    sessionKey: params.lowercaseSessionKey
+      ? normalizeLowercaseStringOrEmpty(rawSessionKey)
+      : rawSessionKey,
     commandTargetSessionKey: params.boundSessionKey ?? params.targetSessionKey,
   };
 }
diff --git a/src/channels/plugins/acp-configured-binding-consumer.ts b/src/channels/plugins/acp-configured-binding-consumer.ts
index d453726b357..ed2bdfd2a2a 100644
--- a/src/channels/plugins/acp-configured-binding-consumer.ts
+++ b/src/channels/plugins/acp-configured-binding-consumer.ts
@@ -13,6 +13,10 @@ import {
   resolveDefaultAgentId,
 } from "../../agents/agent-scope.js";
 import type { OpenClawConfig } from "../../config/config.js";
+import {
+  normalizeLowercaseStringOrEmpty,
+  normalizeOptionalLowercaseString,
+} from "../../shared/string-coerce.js";
 import type {
   ConfiguredBindingRuleConfig,
   ConfiguredBindingTargetFactory,
@@ -26,8 +30,9 @@ function resolveAgentRuntimeAcpDefaults(params: { cfg: OpenClawConfig; ownerAgen
   cwd?: string;
   backend?: string;
 } {
+  const ownerAgentId = normalizeLowercaseStringOrEmpty(params.ownerAgentId);
   const agent = params.cfg.agents?.list?.find(
-    (entry) => entry.id?.trim().toLowerCase() === params.ownerAgentId.toLowerCase(),
+    (entry) => normalizeOptionalLowercaseString(entry.id) === ownerAgentId,
   );
   if (!agent || agent.runtime?.type !== "acp") {
     return {};
diff --git a/src/channels/plugins/config-writes.ts b/src/channels/plugins/config-writes.ts
index d764555b283..fc9891323ee 100644
--- a/src/channels/plugins/config-writes.ts
+++ b/src/channels/plugins/config-writes.ts
@@ -1,4 +1,5 @@
 import type { OpenClawConfig } from "../../config/config.js";
+import { normalizeLowercaseStringOrEmpty } from "../../shared/string-coerce.js";
 import { isInternalMessageChannel } from "../../utils/message-channel.js";
 import {
   authorizeConfigWriteShared,
@@ -40,7 +41,7 @@ export function resolveExplicitConfigWriteTarget(scope: ConfigWriteScope): Confi
 export function resolveConfigWriteTargetFromPath(path: string[]): ConfigWriteTarget {
   return resolveConfigWriteTargetFromPathShared({
     path,
-    normalizeChannelId: (raw) => raw.trim().toLowerCase() as ChannelId,
+    normalizeChannelId: (raw) => normalizeLowercaseStringOrEmpty(raw) as ChannelId,
   });
 }
 
diff --git a/src/channels/plugins/session-conversation.ts b/src/channels/plugins/session-conversation.ts
index 60146950dcc..f3895c740a2 100644
--- a/src/channels/plugins/session-conversation.ts
+++ b/src/channels/plugins/session-conversation.ts
@@ -5,7 +5,10 @@ import {
   type ParsedThreadSessionSuffix,
   type RawSessionConversationRef,
 } from "../../sessions/session-key-utils.js";
-import { normalizeOptionalString } from "../../shared/string-coerce.js";
+import {
+  normalizeOptionalLowercaseString,
+  normalizeOptionalString,
+} from "../../shared/string-coerce.js";
 import { normalizeChannelId as normalizeChatChannelId } from "../registry.js";
 import { getLoadedChannelPlugin, normalizeChannelId as normalizeAnyChannelId } from "./registry.js";
 
@@ -55,7 +58,8 @@ function normalizeResolvedChannel(channel: string): string {
   return (
     normalizeAnyChannelId(channel) ??
     normalizeChatChannelId(channel) ??
-    channel.trim().toLowerCase()
+    normalizeOptionalLowercaseString(channel) ??
+    ""
   );
 }
 
diff --git a/src/channels/targets.ts b/src/channels/targets.ts
index b07f5a45ddf..d2b7ef941a6 100644
--- a/src/channels/targets.ts
+++ b/src/channels/targets.ts
@@ -1,3 +1,5 @@
+import { normalizeLowercaseStringOrEmpty } from "../shared/string-coerce.js";
+
 export type { DirectoryConfigParams } from "./plugins/directory-types.js";
 export type { ChannelDirectoryEntry } from "./plugins/types.js";
 
@@ -16,7 +18,7 @@ export type MessagingTargetParseOptions = {
 };
 
 export function normalizeTargetId(kind: MessagingTargetKind, id: string): string {
-  return `${kind}:${id}`.toLowerCase();
+  return normalizeLowercaseStringOrEmpty(`${kind}:${id}`);
 }
 
 export function buildMessagingTarget(
diff --git a/src/channels/thread-bindings-policy.ts b/src/channels/thread-bindings-policy.ts
index aade4d61d4a..100bf35e3f6 100644
--- a/src/channels/thread-bindings-policy.ts
+++ b/src/channels/thread-bindings-policy.ts
@@ -1,5 +1,6 @@
 import type { OpenClawConfig } from "../config/config.js";
 import { normalizeAccountId } from "../routing/session-key.js";
+import { normalizeLowercaseStringOrEmpty } from "../shared/string-coerce.js";
 import { getChannelPlugin } from "./plugins/index.js";
 
 const DEFAULT_THREAD_BINDING_IDLE_HOURS = 24;
@@ -28,9 +29,7 @@ export type ThreadBindingSpawnPolicy = {
 };
 
 function normalizeChannelId(value: string | undefined | null): string {
-  return String(value ?? "")
-    .trim()
-    .toLowerCase();
+  return normalizeLowercaseStringOrEmpty(value);
 }
 
 export function supportsAutomaticThreadBindingSpawn(channel: string): boolean {
diff --git a/src/commands/channels/add.ts b/src/commands/channels/add.ts
index 401abf01873..0574db7ddd4 100644
--- a/src/commands/channels/add.ts
+++ b/src/commands/channels/add.ts
@@ -8,6 +8,7 @@ import type { ChannelId, ChannelPlugin, ChannelSetupInput } from "../../channels
 import { replaceConfigFile, type OpenClawConfig } from "../../config/config.js";
 import { DEFAULT_ACCOUNT_ID, normalizeAccountId } from "../../routing/session-key.js";
 import { defaultRuntime, type RuntimeEnv } from "../../runtime.js";
+import { normalizeOptionalLowercaseString } from "../../shared/string-coerce.js";
 import { createClackPrompter } from "../../wizard/clack-prompter.js";
 import { applyAgentBindings, describeBinding } from "../agents.bindings.js";
 import { isCatalogChannelInstalled } from "../channel-setup/discovery.js";
@@ -28,16 +29,18 @@ export type ChannelsAddOptions = {
 } & Omit<ChannelSetupInput, "groupChannels" | "dmAllowlist" | "initialSyncLimit">;
 
 function resolveCatalogChannelEntry(raw: string, cfg: OpenClawConfig | null) {
-  const trimmed = raw.trim().toLowerCase();
+  const trimmed = normalizeOptionalLowercaseString(raw);
   if (!trimmed) {
     return undefined;
   }
   const workspaceDir = cfg ? resolveAgentWorkspaceDir(cfg, resolveDefaultAgentId(cfg)) : undefined;
   return listChannelPluginCatalogEntries({ workspaceDir }).find((entry) => {
-    if (entry.id.toLowerCase() === trimmed) {
+    if (normalizeOptionalLowercaseString(entry.id) === trimmed) {
       return true;
     }
-    return (entry.meta.aliases ?? []).some((alias) => alias.trim().toLowerCase() === trimmed);
+    return (entry.meta.aliases ?? []).some(
+      (alias) => normalizeOptionalLowercaseString(alias) === trimmed,
+    );
   });
 }
 
diff --git a/src/commands/channels/capabilities.ts b/src/commands/channels/capabilities.ts
index 325f6e8513a..f380aaf8888 100644
--- a/src/commands/channels/capabilities.ts
+++ b/src/commands/channels/capabilities.ts
@@ -18,7 +18,10 @@ import {
 import { danger } from "../../globals.js";
 import { formatErrorMessage } from "../../infra/errors.js";
 import { defaultRuntime, type RuntimeEnv, writeRuntimeJson } from "../../runtime.js";
-import { normalizeOptionalString } from "../../shared/string-coerce.js";
+import {
+  normalizeLowercaseStringOrEmpty,
+  normalizeOptionalString,
+} from "../../shared/string-coerce.js";
 import { theme } from "../../terminal/theme.js";
 import { resolveInstallableChannelPlugin } from "../channel-setup/channel-plugin-resolution.js";
 import { formatChannelAccountLabel, requireValidConfig } from "./shared.js";
@@ -220,7 +223,7 @@ export async function channelsCapabilitiesCommand(
   }
   let cfg = loadedCfg;
   const timeoutMs = normalizeTimeout(opts.timeout, 10_000);
-  const rawChannel = typeof opts.channel === "string" ? opts.channel.trim().toLowerCase() : "";
+  const rawChannel = normalizeLowercaseStringOrEmpty(opts.channel);
   const rawTarget = typeof opts.target === "string" ? opts.target.trim() : "";
 
   if (opts.account && (!rawChannel || rawChannel === "all")) {
diff --git a/src/commands/channels/logs.ts b/src/commands/channels/logs.ts
index e3863b9289a..d23af5cd5ad 100644
--- a/src/commands/channels/logs.ts
+++ b/src/commands/channels/logs.ts
@@ -3,6 +3,7 @@ import { listChannelPlugins } from "../../channels/plugins/index.js";
 import { getResolvedLoggerSettings } from "../../logging.js";
 import { parseLogLine } from "../../logging/parse-log-line.js";
 import { defaultRuntime, type RuntimeEnv, writeRuntimeJson } from "../../runtime.js";
+import { normalizeLowercaseStringOrEmpty } from "../../shared/string-coerce.js";
 import { theme } from "../../terminal/theme.js";
 
 export type ChannelsLogsOptions = {
@@ -20,7 +21,7 @@ const getChannelSet = () =>
   new Set<string>([...listChannelPlugins().map((plugin) => plugin.id), "all"]);
 
 function parseChannelFilter(raw?: string) {
-  const trimmed = raw?.trim().toLowerCase();
+  const trimmed = normalizeLowercaseStringOrEmpty(raw);
   if (!trimmed) {
     return "all";
   }
diff --git a/src/commands/channels/resolve.ts b/src/commands/channels/resolve.ts
index c3b7db9faff..4fe5004a6e4 100644
--- a/src/commands/channels/resolve.ts
+++ b/src/commands/channels/resolve.ts
@@ -6,6 +6,10 @@ import { loadConfig, readConfigFileSnapshot, replaceConfigFile } from "../../con
 import { danger } from "../../globals.js";
 import { resolveMessageChannelSelection } from "../../infra/outbound/channel-selection.js";
 import { type RuntimeEnv, writeRuntimeJson } from "../../runtime.js";
+import {
+  normalizeLowercaseStringOrEmpty,
+  normalizeOptionalLowercaseString,
+} from "../../shared/string-coerce.js";
 import { resolveInstallableChannelPlugin } from "../channel-setup/channel-plugin-resolution.js";
 
 export type ChannelsResolveOptions = {
@@ -71,10 +75,10 @@ function detectAutoKindForPlugin(
     return generic;
   }
   const trimmed = input.trim();
-  const lowered = trimmed.toLowerCase();
+  const lowered = normalizeLowercaseStringOrEmpty(trimmed);
   const prefixes = [plugin.id, ...(plugin.meta?.aliases ?? [])]
-    .map((entry) => entry.trim().toLowerCase())
-    .filter(Boolean);
+    .map((entry) => normalizeOptionalLowercaseString(entry))
+    .filter((entry): entry is string => Boolean(entry));
   for (const prefix of prefixes) {
     if (!lowered.startsWith(`${prefix}:`)) {
       continue;