refactor: dedupe auto-reply lowercase helpers

src/auto-reply/command-detection.ts

@@ -1,5 +1,8 @@
 import type { OpenClawConfig } from "../config/types.js";
-import { normalizeOptionalLowercaseString } from "../shared/string-coerce.js";
+import {
+  normalizeLowercaseStringOrEmpty,
+  normalizeOptionalLowercaseString,
+} from "../shared/string-coerce.js";
 import {
   type CommandNormalizeOptions,
   listChatCommands,
@@ -29,7 +32,7 @@ export function hasControlCommand(
   if (!normalizedBody) {
     return false;
   }
-  const lowered = normalizedBody.toLowerCase();
+  const lowered = normalizeLowercaseStringOrEmpty(normalizedBody);
   const commands = cfg ? listChatCommandsForConfig(cfg) : listChatCommands();
   for (const command of commands) {
     for (const alias of command.textAliases) {

src/auto-reply/commands-args.ts

@@ -1,3 +1,4 @@
+import { normalizeOptionalLowercaseString } from "../shared/string-coerce.js";
 import type { CommandArgValues } from "./commands-registry.types.js";
 
 export type CommandArgsFormatter = (values: CommandArgValues) => string | undefined;
@@ -28,7 +29,7 @@ function formatActionArgs(
     formatKnownAction: (action: string, path: string | undefined) => string | undefined;
   },
 ): string | undefined {
-  const action = normalizeArgValue(values.action)?.toLowerCase();
+  const action = normalizeOptionalLowercaseString(normalizeArgValue(values.action));
   const path = normalizeArgValue(values.path);
   const value = normalizeArgValue(values.value);
   if (!action) {

src/auto-reply/commands-registry.ts

@@ -403,7 +403,7 @@ export function normalizeCommandBody(raw: string, options?: CommandNormalizeOpti
     ? normalized.match(/^\/([^\s@]+)@([^\s]+)(.*)$/)
     : null;
   const commandBody =
-    mentionMatch && mentionMatch[2].toLowerCase() === normalizedBotUsername
+    mentionMatch && normalizeLowercaseStringOrEmpty(mentionMatch[2]) === normalizedBotUsername
       ? `/${mentionMatch[1]}${mentionMatch[3] ?? ""}`
       : normalized;
 
@@ -419,7 +419,7 @@ export function normalizeCommandBody(raw: string, options?: CommandNormalizeOpti
     return commandBody;
   }
   const [, token, rest] = tokenMatch;
-  const tokenKey = `/${token.toLowerCase()}`;
+  const tokenKey = `/${normalizeLowercaseStringOrEmpty(token)}`;
   const tokenSpec = textAliasMap.get(tokenKey);
   if (!tokenSpec) {
     return commandBody;

src/auto-reply/envelope.ts

@@ -8,6 +8,7 @@ import {
   formatZonedTimestamp,
 } from "../infra/format-time/format-datetime.ts";
 import { formatTimeAgo } from "../infra/format-time/format-relative.ts";
+import { normalizeLowercaseStringOrEmpty } from "../shared/string-coerce.js";
 
 export type AgentEnvelopeParams = {
   channel: string;
@@ -88,7 +89,7 @@ function resolveEnvelopeTimezone(options: NormalizedEnvelopeOptions): ResolvedEn
   if (!trimmed) {
     return { mode: "local" };
   }
-  const lowered = trimmed.toLowerCase();
+  const lowered = normalizeLowercaseStringOrEmpty(trimmed);
   if (lowered === "utc" || lowered === "gmt") {
     return { mode: "utc" };
   }

src/auto-reply/media-note.ts

@@ -1,3 +1,4 @@
+import { normalizeLowercaseStringOrEmpty } from "../shared/string-coerce.js";
 import type { MsgContext } from "./templating.js";
 
 function formatMediaAttachedLine(params: {
@@ -37,7 +38,7 @@ function isAudioPath(path: string | undefined): boolean {
   if (!path) {
     return false;
   }
-  const lower = path.toLowerCase();
+  const lower = normalizeLowercaseStringOrEmpty(path);
   for (const ext of AUDIO_EXTENSIONS) {
     if (lower.endsWith(ext)) {
       return true;
@@ -113,7 +114,8 @@ export function buildInboundMediaNote(ctx: MsgContext): string | undefined {
       // Note: Only trust MIME type from per-entry types array, not fallback ctx.MediaType
       // which could misclassify non-audio attachments (greptile review feedback)
       const hasPerEntryType = types !== undefined;
-      const isAudioByMime = hasPerEntryType && entry.type?.toLowerCase().startsWith("audio/");
+      const isAudioByMime =
+        hasPerEntryType && normalizeLowercaseStringOrEmpty(entry.type).startsWith("audio/");
       const isAudioEntry = isAudioPath(entry.path) || isAudioByMime;
       if (!isAudioEntry) {
         return true;

src/auto-reply/model-runtime.ts

@@ -1,4 +1,5 @@
 import type { SessionEntry } from "../config/sessions.js";
+import { normalizeLowercaseStringOrEmpty } from "../shared/string-coerce.js";
 
 export function formatProviderModelRef(providerRaw: string, modelRaw: string): string {
   const provider = String(providerRaw ?? "").trim();
@@ -10,7 +11,7 @@ export function formatProviderModelRef(providerRaw: string, modelRaw: string): s
     return provider;
   }
   const prefix = `${provider}/`;
-  if (model.toLowerCase().startsWith(prefix.toLowerCase())) {
+  if (normalizeLowercaseStringOrEmpty(model).startsWith(normalizeLowercaseStringOrEmpty(prefix))) {
     const normalizedModel = model.slice(prefix.length).trim();
     if (normalizedModel) {
       return `${provider}/${normalizedModel}`;
@@ -31,7 +32,7 @@ function normalizeModelWithinProvider(provider: string, modelRaw: string): strin
     return model;
   }
   const prefix = `${provider}/`;
-  if (model.toLowerCase().startsWith(prefix.toLowerCase())) {
+  if (normalizeLowercaseStringOrEmpty(model).startsWith(normalizeLowercaseStringOrEmpty(prefix))) {
     const withoutPrefix = model.slice(prefix.length).trim();
     if (withoutPrefix) {
       return withoutPrefix;

src/auto-reply/reply/abort-primitives.ts

@@ -1,3 +1,4 @@
+import { normalizeLowercaseStringOrEmpty } from "../../shared/string-coerce.js";
 import { normalizeCommandBody, type CommandNormalizeOptions } from "../commands-registry.js";
 
 const ABORT_TRIGGERS = new Set([
@@ -49,9 +50,7 @@ const ABORT_MEMORY_MAX = 2000;
 const TRAILING_ABORT_PUNCTUATION_RE = /[.!?…,，。;；:：'"’”)\]}]+$/u;
 
 function normalizeAbortTriggerText(text: string): string {
-  return text
-    .trim()
-    .toLowerCase()
+  return normalizeLowercaseStringOrEmpty(text)
     .replace(/[’`]/g, "'")
     .replace(/\s+/g, " ")
     .replace(TRAILING_ABORT_PUNCTUATION_RE, "")
@@ -74,7 +73,7 @@ export function isAbortRequestText(text?: string, options?: CommandNormalizeOpti
   if (!normalized) {
     return false;
   }
-  const normalizedLower = normalized.toLowerCase();
+  const normalizedLower = normalizeLowercaseStringOrEmpty(normalized);
   return (
     normalizedLower === "/stop" ||
     normalizeAbortTriggerText(normalizedLower) === "/stop" ||

src/auto-reply/reply/acp-reset-target.ts

@@ -8,7 +8,10 @@ import { listAcpBindings } from "../../config/bindings.js";
 import type { OpenClawConfig } from "../../config/config.js";
 import { getSessionBindingService } from "../../infra/outbound/session-binding-service.js";
 import { DEFAULT_ACCOUNT_ID, isAcpSessionKey } from "../../routing/session-key.js";
-import { normalizeOptionalString } from "../../shared/string-coerce.js";
+import {
+  normalizeLowercaseStringOrEmpty,
+  normalizeOptionalString,
+} from "../../shared/string-coerce.js";
 
 const acpResetTargetDeps = {
   getSessionBindingService,
@@ -57,7 +60,9 @@ function resolveRawConfiguredAcpSessionKey(params: {
   parentConversationId?: string;
 }): string | undefined {
   for (const binding of acpResetTargetDeps.listAcpBindings(params.cfg)) {
-    const bindingChannel = (normalizeOptionalString(binding.match.channel) ?? "").toLowerCase();
+    const bindingChannel = normalizeLowercaseStringOrEmpty(
+      normalizeOptionalString(binding.match.channel),
+    );
     if (!bindingChannel || bindingChannel !== params.channel) {
       continue;
     }
@@ -111,7 +116,7 @@ export function resolveEffectiveResetTargetSessionKey(params: {
     activeSessionKey && isAcpSessionKey(activeSessionKey) ? activeSessionKey : undefined;
   const activeIsNonAcp = Boolean(activeSessionKey) && !activeAcpSessionKey;
 
-  const channel = (normalizeOptionalString(params.channel) ?? "").toLowerCase();
+  const channel = normalizeLowercaseStringOrEmpty(normalizeOptionalString(params.channel));
   const conversationId = normalizeOptionalString(params.conversationId) ?? "";
   if (!channel || !conversationId) {
     return activeAcpSessionKey;

src/auto-reply/reply/agent-runner-execution.ts

@@ -36,6 +36,7 @@ import { CommandLaneClearedError, GatewayDrainingError } from "../../process/com
 import { defaultRuntime } from "../../runtime.js";
 import {
   hasNonEmptyString,
+  normalizeLowercaseStringOrEmpty,
   normalizeOptionalString,
   readStringValue,
 } from "../../shared/string-coerce.js";
@@ -293,7 +294,7 @@ function isPureTransientRateLimitSummary(err: unknown): boolean {
 }
 
 function isToolResultTurnMismatchError(message: string): boolean {
-  const lower = message.toLowerCase();
+  const lower = normalizeLowercaseStringOrEmpty(message);
   return (
     lower.includes("toolresult") &&
     lower.includes("tooluse") &&

src/auto-reply/reply/agent-runner-reminder-guard.ts

@@ -1,4 +1,5 @@
 import { loadCronStore, resolveCronStorePath } from "../../cron/store.js";
+import { normalizeLowercaseStringOrEmpty } from "../../shared/string-coerce.js";
 import type { ReplyPayload } from "../types.js";
 
 export const UNSCHEDULED_REMINDER_NOTE =
@@ -10,11 +11,11 @@ const REMINDER_COMMITMENT_PATTERNS: RegExp[] = [
 ];
 
 export function hasUnbackedReminderCommitment(text: string): boolean {
-  const normalized = text.toLowerCase();
+  const normalized = normalizeLowercaseStringOrEmpty(text);
   if (!normalized.trim()) {
     return false;
   }
-  if (normalized.includes(UNSCHEDULED_REMINDER_NOTE.toLowerCase())) {
+  if (normalized.includes(normalizeLowercaseStringOrEmpty(UNSCHEDULED_REMINDER_NOTE))) {
     return false;
   }
   return REMINDER_COMMITMENT_PATTERNS.some((pattern) => pattern.test(text));

src/auto-reply/reply/commands-acp/context.ts

@@ -1,4 +1,5 @@
 import { normalizeConversationText } from "../../../acp/conversation-id.js";
+import { normalizeLowercaseStringOrEmpty } from "../../../shared/string-coerce.js";
 import type { HandleCommandsParams } from "../commands-types.js";
 import {
   resolveConversationBindingAccountIdFromMessage,
@@ -9,7 +10,7 @@ import {
 
 export function resolveAcpCommandChannel(params: HandleCommandsParams): string {
   const resolved = resolveConversationBindingChannelFromMessage(params.ctx, params.command.channel);
-  return normalizeConversationText(resolved).toLowerCase();
+  return normalizeLowercaseStringOrEmpty(normalizeConversationText(resolved));
 }
 
 export function resolveAcpCommandAccountId(params: HandleCommandsParams): string {

src/auto-reply/reply/commands-acp/diagnostics.ts

@@ -6,7 +6,10 @@ import { resolveSessionStorePathForAcp } from "../../../acp/runtime/session-meta
 import { loadSessionStore } from "../../../config/sessions.js";
 import type { SessionEntry } from "../../../config/sessions/types.js";
 import { getSessionBindingService } from "../../../infra/outbound/session-binding-service.js";
-import { normalizeOptionalString } from "../../../shared/string-coerce.js";
+import {
+  normalizeLowercaseStringOrEmpty,
+  normalizeOptionalString,
+} from "../../../shared/string-coerce.js";
 import type { CommandHandlerResult, HandleCommandsParams } from "../commands-types.js";
 import { resolveAcpCommandBindingContext } from "./context.js";
 import {
@@ -101,7 +104,7 @@ export async function handleAcpDoctorAction(
     lines.push(formatAcpRuntimeErrorText(acpError));
     lines.push(`next: ${installHint}`);
     lines.push(`next: openclaw config set plugins.entries.${backendId}.enabled true`);
-    if (backendId.toLowerCase() === "acpx") {
+    if (normalizeLowercaseStringOrEmpty(backendId) === "acpx") {
       lines.push("next: verify acpx is installed (`acpx --help`).");
     }
     return stopWithText(lines.join("\n"));

src/auto-reply/reply/commands-acp/runtime-options.ts

@@ -8,6 +8,7 @@ import {
   validateRuntimePermissionProfileInput,
 } from "../../../acp/control-plane/runtime-options.js";
 import { resolveAcpSessionIdentifierLinesFromIdentity } from "../../../acp/runtime/session-identifiers.js";
+import { normalizeLowercaseStringOrEmpty } from "../../../shared/string-coerce.js";
 import { findLatestTaskForRelatedSessionKeyForOwner } from "../../../tasks/task-owner-access.js";
 import { sanitizeTaskStatusText } from "../../../tasks/task-status.js";
 import type { CommandHandlerResult, HandleCommandsParams } from "../commands-types.js";
@@ -230,7 +231,7 @@ export async function handleAcpSetAction(
 
   return await withAcpCommandErrorBoundary({
     run: async () => {
-      const lowerKey = key.toLowerCase();
+      const lowerKey = normalizeLowercaseStringOrEmpty(key);
       if (lowerKey === "cwd") {
         const cwd = validateRuntimeCwdInput(value);
         const options = await getAcpSessionManager().updateSessionRuntimeOptions({

src/auto-reply/reply/commands-approve.ts

@@ -7,6 +7,7 @@ import { logVerbose } from "../../globals.js";
 import { isApprovalNotFoundError } from "../../infra/approval-errors.js";
 import { resolveApprovalCommandAuthorization } from "../../infra/channel-approval-auth.js";
 import { formatErrorMessage } from "../../infra/errors.js";
+import { normalizeLowercaseStringOrEmpty } from "../../shared/string-coerce.js";
 import { GATEWAY_CLIENT_MODES, GATEWAY_CLIENT_NAMES } from "../../utils/message-channel.js";
 import { resolveChannelAccountId } from "./channel-context.js";
 import { requireGatewayClientScopeForInternalChannel } from "./command-gates.js";
@@ -53,8 +54,8 @@ function parseApproveCommand(raw: string): ParsedApproveCommand | null {
     return { ok: false, error: APPROVE_USAGE_TEXT };
   }
 
-  const first = tokens[0].toLowerCase();
-  const second = tokens[1].toLowerCase();
+  const first = normalizeLowercaseStringOrEmpty(tokens[0]);
+  const second = normalizeLowercaseStringOrEmpty(tokens[1]);
 
   if (DECISION_ALIASES[first]) {
     return {

src/auto-reply/reply/commands-compact.ts

@@ -1,6 +1,7 @@
 import type { OpenClawConfig } from "../../config/config.js";
 import { logVerbose } from "../../globals.js";
 import {
+  normalizeLowercaseStringOrEmpty,
   normalizeOptionalLowercaseString,
   normalizeOptionalString,
 } from "../../shared/string-coerce.js";
@@ -22,7 +23,7 @@ function extractCompactInstructions(params: {
   if (!trimmed) {
     return undefined;
   }
-  const lowered = trimmed.toLowerCase();
+  const lowered = normalizeLowercaseStringOrEmpty(trimmed);
   const prefix = lowered.startsWith("/compact") ? "/compact" : null;
   if (!prefix) {
     return undefined;
@@ -50,7 +51,7 @@ function formatCompactionReason(reason?: string): string | undefined {
     return undefined;
   }
 
-  const lower = text.toLowerCase();
+  const lower = normalizeLowercaseStringOrEmpty(text);
   if (lower.includes("nothing to compact")) {
     return "nothing compactable in this session yet";
   }

src/auto-reply/reply/commands-context-report.ts

@@ -8,6 +8,7 @@ import {
   resolveFreshSessionTotalTokens,
   type SessionSystemPromptReport,
 } from "../../config/sessions/types.js";
+import { normalizeLowercaseStringOrEmpty } from "../../shared/string-coerce.js";
 import { estimateTokensFromChars } from "../../utils/cjk-chars.js";
 import type { ReplyPayload } from "../types.js";
 import { resolveCommandsSystemPromptBundle } from "./commands-system-prompt.js";
@@ -76,7 +77,7 @@ async function resolveContextReport(
 
 export async function buildContextReply(params: HandleCommandsParams): Promise<ReplyPayload> {
   const args = parseContextArgs(params.command.commandBodyNormalized);
-  const sub = args.split(/\s+/).filter(Boolean)[0]?.toLowerCase() ?? "";
+  const sub = normalizeLowercaseStringOrEmpty(args.split(/\s+/).filter(Boolean)[0]);
 
   if (!sub || sub === "help") {
     return {

src/auto-reply/reply/commands-models.ts

@@ -11,7 +11,10 @@ import {
 import { getChannelPlugin } from "../../channels/plugins/index.js";
 import type { OpenClawConfig } from "../../config/config.js";
 import type { SessionEntry } from "../../config/sessions.js";
-import { normalizeOptionalString } from "../../shared/string-coerce.js";
+import {
+  normalizeLowercaseStringOrEmpty,
+  normalizeOptionalString,
+} from "../../shared/string-coerce.js";
 import type { ReplyPayload } from "../types.js";
 import { rejectUnauthorizedCommand } from "./command-gates.js";
 import type { CommandHandler } from "./commands-types.js";
@@ -149,7 +152,7 @@ function parseModelsArgs(raw: string): {
   let page = 1;
   let all = false;
   for (const token of tokens.slice(1)) {
-    const lower = token.toLowerCase();
+    const lower = normalizeLowercaseStringOrEmpty(token);
     if (lower === "all" || lower === "--all") {
       all = true;
       continue;
@@ -171,7 +174,7 @@ function parseModelsArgs(raw: string): {
 
   let pageSize = PAGE_SIZE_DEFAULT;
   for (const token of tokens) {
-    const lower = token.toLowerCase();
+    const lower = normalizeLowercaseStringOrEmpty(token);
     if (lower.startsWith("limit=") || lower.startsWith("size=")) {
       const rawValue = lower.slice(lower.indexOf("=") + 1);
       const value = Number.parseInt(rawValue, 10);

src/auto-reply/reply/commands-plugins.ts

@@ -418,7 +418,7 @@ export const handlePluginsCommand: CommandHandler = async (params, allowTextComm
         reply: { text: formatPluginsList(loaded.report) },
       };
     }
-    if (pluginsCommand.name.toLowerCase() === "all") {
+    if (normalizeOptionalLowercaseString(pluginsCommand.name) === "all") {
       return {
         shouldContinue: false,
         reply: {

src/auto-reply/reply/commands-session.ts

@@ -13,6 +13,7 @@ import type { SessionBindingRecord } from "../../infra/outbound/session-binding-
 import { scheduleGatewaySigusr1Restart, triggerOpenClawRestart } from "../../infra/restart.js";
 import { loadCostUsageSummary, loadSessionCostSummary } from "../../infra/session-cost-usage.js";
 import {
+  normalizeLowercaseStringOrEmpty,
   normalizeOptionalLowercaseString,
   normalizeOptionalString,
 } from "../../shared/string-coerce.js";
@@ -262,7 +263,7 @@ export const handleUsageCommand: CommandHandler = async (params, allowTextComman
 
   const rawArgs = normalized === "/usage" ? "" : normalized.slice("/usage".length).trim();
   const requested = rawArgs ? normalizeUsageDisplay(rawArgs) : undefined;
-  if (rawArgs.toLowerCase().startsWith("cost")) {
+  if (normalizeLowercaseStringOrEmpty(rawArgs).startsWith("cost")) {
     const sessionSummary = await loadSessionCostSummary({
       sessionId: params.sessionEntry?.sessionId,
       sessionEntry: params.sessionEntry,
@@ -347,7 +348,7 @@ export const handleFastCommand: CommandHandler = async (params, allowTextCommand
   }
 
   const rawArgs = normalized === "/fast" ? "" : normalized.slice("/fast".length).trim();
-  const rawMode = rawArgs.toLowerCase();
+  const rawMode = normalizeLowercaseStringOrEmpty(rawArgs);
   if (!rawMode || rawMode === "status") {
     const state = resolveFastModeState({
       cfg: params.cfg,
@@ -406,7 +407,7 @@ export const handleSessionCommand: CommandHandler = async (params, allowTextComm
 
   const rest = normalized.slice(SESSION_COMMAND_PREFIX.length).trim();
   const tokens = rest.split(/\s+/).filter(Boolean);
-  const action = tokens[0]?.toLowerCase();
+  const action = normalizeOptionalLowercaseString(tokens[0]);
   if (action !== SESSION_ACTION_IDLE && action !== SESSION_ACTION_MAX_AGE) {
     return {
       shouldContinue: false,

src/auto-reply/reply/commands-subagents/action-log.ts

@@ -1,4 +1,5 @@
 import { callGateway } from "../../../gateway/call.js";
+import { normalizeLowercaseStringOrEmpty } from "../../../shared/string-coerce.js";
 import type { CommandHandlerResult } from "../commands-types.js";
 import { formatRunLabel } from "../subagents-utils.js";
 import {
@@ -19,7 +20,9 @@ export async function handleSubagentsLogAction(
     return stopWithText("📜 Usage: /subagents log <id|#> [limit]");
   }
 
-  const includeTools = restTokens.some((token) => token.toLowerCase() === "tools");
+  const includeTools = restTokens.some(
+    (token) => normalizeLowercaseStringOrEmpty(token) === "tools",
+  );
   const limitToken = restTokens.find((token) => /^\d+$/.test(token));
   const limit = limitToken ? Math.min(200, Math.max(1, Number.parseInt(limitToken, 10))) : 20;
 

src/auto-reply/reply/commands-subagents/shared.ts

@@ -19,7 +19,10 @@ import { formatTimeAgo } from "../../../infra/format-time/format-relative.ts";
 import { parseAgentSessionKey } from "../../../routing/session-key.js";
 import { isSubagentSessionKey } from "../../../routing/session-key.js";
 import { looksLikeSessionId } from "../../../sessions/session-id.js";
-import { normalizeOptionalString } from "../../../shared/string-coerce.js";
+import {
+  normalizeLowercaseStringOrEmpty,
+  normalizeOptionalString,
+} from "../../../shared/string-coerce.js";
 import {
   formatDurationCompact,
   formatTokenUsageDisplay,
@@ -114,7 +117,11 @@ export function formatSubagentListLine(params: {
         ? params.sessionEntry.modelOverride
         : null,
     fallbackModel: params.entry.model,
-  })}, ${runtime}${usageText ? `, ${usageText}` : ""}) ${status}${task.toLowerCase() !== label.toLowerCase() ? ` - ${task}` : ""}`;
+  })}, ${runtime}${usageText ? `, ${usageText}` : ""}) ${status}${
+    normalizeLowercaseStringOrEmpty(task) !== normalizeLowercaseStringOrEmpty(label)
+      ? ` - ${task}`
+      : ""
+  }`;
 }
 
 function formatTimestamp(valueMs?: number) {
@@ -268,7 +275,7 @@ export function resolveSubagentsAction(params: {
 }): SubagentsAction | null {
   if (params.handledPrefix === COMMAND) {
     const [actionRaw] = params.restTokens;
-    const action = (actionRaw?.toLowerCase() || "list") as SubagentsAction;
+    const action = (normalizeLowercaseStringOrEmpty(actionRaw) || "list") as SubagentsAction;
     if (!ACTIONS.has(action)) {
       return null;
     }

src/auto-reply/reply/commands-tts.ts

@@ -47,7 +47,7 @@ function parseTtsCommand(normalized: string): ParsedTtsCommand | null {
     return { action: "status", args: "" };
   }
   const [action, ...tail] = rest.split(/\s+/);
-  return { action: action.toLowerCase(), args: tail.join(" ").trim() };
+  return { action: normalizeOptionalLowercaseString(action) ?? "", args: tail.join(" ").trim() };
 }
 
 function formatAttemptDetails(attempts: TtsAttemptDetail[] | undefined): string | undefined {

src/auto-reply/reply/conversation-binding-input.ts

@@ -2,6 +2,7 @@ import { normalizeConversationText } from "../../acp/conversation-id.js";
 import { resolveConversationBindingContext } from "../../channels/conversation-binding-context.js";
 import type { OpenClawConfig } from "../../config/config.js";
 import { getActivePluginChannelRegistry } from "../../plugins/runtime.js";
+import { normalizeLowercaseStringOrEmpty } from "../../shared/string-coerce.js";
 import type { MsgContext } from "../templating.js";
 import type { HandleCommandsParams } from "./commands-types.js";
 
@@ -25,7 +26,7 @@ type BindingMsgContext = Pick<
 
 function resolveBindingChannel(ctx: BindingMsgContext, commandChannel?: string | null): string {
   const raw = ctx.OriginatingChannel ?? commandChannel ?? ctx.Surface ?? ctx.Provider;
-  return normalizeConversationText(raw).toLowerCase();
+  return normalizeLowercaseStringOrEmpty(normalizeConversationText(raw));
 }
 
 function resolveBindingAccountId(params: {

src/auto-reply/reply/directive-handling.auth.ts

@@ -13,6 +13,7 @@ import {
 import { findNormalizedProviderValue, normalizeProviderId } from "../../agents/model-selection.js";
 import type { OpenClawConfig } from "../../config/config.js";
 import { coerceSecretRef } from "../../config/types.secrets.js";
+import { normalizeLowercaseStringOrEmpty } from "../../shared/string-coerce.js";
 import { shortenHomePath } from "../../utils.js";
 import { maskApiKey } from "../../utils/mask-api-key.js";
 
@@ -196,7 +197,7 @@ export const resolveAuthLabel = async (
   if (envKey) {
     const isOAuthEnv =
       envKey.source.includes("ANTHROPIC_OAUTH_TOKEN") ||
-      envKey.source.toLowerCase().includes("oauth");
+      normalizeLowercaseStringOrEmpty(envKey.source).includes("oauth");
     const label = isOAuthEnv ? "OAuth (env)" : maskApiKey(envKey.apiKey);
     return { label, source: mode === "verbose" ? envKey.source : "" };
   }

src/auto-reply/reply/directive-handling.impl.ts

@@ -7,6 +7,7 @@ import { updateSessionStore } from "../../config/sessions.js";
 import { enqueueSystemEvent } from "../../infra/system-events.js";
 import { applyVerboseOverride } from "../../sessions/level-overrides.js";
 import { applyModelOverrideToSessionEntry } from "../../sessions/model-overrides.js";
+import { normalizeLowercaseStringOrEmpty } from "../../shared/string-coerce.js";
 import { formatThinkingLevels, formatXHighModelHint, supportsXHighThinking } from "../thinking.js";
 import type { ReplyPayload } from "../types.js";
 import { resolveModelSelectionFromDirective } from "./directive-handling.model-selection.js";
@@ -152,7 +153,10 @@ export async function handleDirectiveOnly(
     };
   }
   if (directives.hasFastDirective && directives.fastMode === undefined) {
-    if (!directives.rawFastMode || directives.rawFastMode.toLowerCase() === "status") {
+    if (
+      !directives.rawFastMode ||
+      normalizeLowercaseStringOrEmpty(directives.rawFastMode) === "status"
+    ) {
       const sourceSuffix =
         effectiveFastModeSource === "config"
           ? " (config)"

src/auto-reply/reply/directive-handling.model-picker.ts

@@ -4,7 +4,10 @@ import {
   normalizeProviderId,
 } from "../../agents/model-selection.js";
 import type { OpenClawConfig } from "../../config/config.js";
-import { normalizeOptionalString } from "../../shared/string-coerce.js";
+import {
+  normalizeLowercaseStringOrEmpty,
+  normalizeOptionalString,
+} from "../../shared/string-coerce.js";
 
 export type ModelPickerCatalogEntry = {
   provider: string;
@@ -78,7 +81,9 @@ export function buildModelPickerItems(catalog: ModelPickerCatalogEntry[]): Model
     if (providerOrder !== 0) {
       return providerOrder;
     }
-    return a.model.toLowerCase().localeCompare(b.model.toLowerCase());
+    return normalizeLowercaseStringOrEmpty(a.model).localeCompare(
+      normalizeLowercaseStringOrEmpty(b.model),
+    );
   });
 
   return out;

src/auto-reply/reply/directive-handling.model.ts

@@ -9,7 +9,10 @@ import {
 import { getChannelPlugin } from "../../channels/plugins/index.js";
 import type { OpenClawConfig } from "../../config/config.js";
 import type { SessionEntry } from "../../config/sessions.js";
-import { normalizeOptionalString } from "../../shared/string-coerce.js";
+import {
+  normalizeLowercaseStringOrEmpty,
+  normalizeOptionalString,
+} from "../../shared/string-coerce.js";
 import { shortenHomePath } from "../../utils.js";
 import { resolveSelectedAndActiveModel } from "../model-runtime.js";
 import type { ReplyPayload } from "../types.js";
@@ -207,7 +210,7 @@ export async function maybeHandleModelDirectiveInfo(params: {
   }
 
   const rawDirective = normalizeOptionalString(params.directives.rawModelDirective);
-  const directive = rawDirective?.toLowerCase();
+  const directive = rawDirective ? normalizeLowercaseStringOrEmpty(rawDirective) : undefined;
   const wantsStatus = directive === "status";
   const wantsSummary = !rawDirective;
   const wantsLegacyList = directive === "list";

src/auto-reply/reply/dispatch-acp.ts

@@ -15,6 +15,7 @@ import { generateSecureUuid } from "../../infra/secure-random.js";
 import { prefixSystemMessage } from "../../infra/system-message.js";
 import { resolveAgentIdFromSessionKey } from "../../routing/session-key.js";
 import {
+  normalizeLowercaseStringOrEmpty,
   normalizeOptionalLowercaseString,
   normalizeOptionalString,
 } from "../../shared/string-coerce.js";
@@ -340,10 +341,9 @@ export async function tryDispatchAcpReply(params: {
         normalizeOptionalString(params.cfg.acp?.defaultAgent) ??
         resolveAgentIdFromSessionKey(canonicalSessionKey))
       : resolveAgentIdFromSessionKey(canonicalSessionKey);
-  const normalizedDispatchChannel =
-    normalizeOptionalString(
-      params.ctx.OriginatingChannel ?? params.ctx.Surface ?? params.ctx.Provider,
-    )?.toLowerCase() ?? "";
+  const normalizedDispatchChannel = normalizeOptionalLowercaseString(
+    params.ctx.OriginatingChannel ?? params.ctx.Surface ?? params.ctx.Provider,
+  );
   const explicitDispatchAccountId = normalizeOptionalString(params.ctx.AccountId);
   const effectiveDispatchAccountId =
     explicitDispatchAccountId ??
@@ -382,7 +382,7 @@ export async function tryDispatchAcpReply(params: {
         `acp-dispatch: session=${sessionKey} outcome=error code=${acpResolution.error.code} latencyMs=${Date.now() - acpDispatchStartedAt} queueDepth=${acpStats.turns.queueDepth} activeRuntimes=${acpStats.runtimeCache.activeSessions}`,
       );
       params.recordProcessed("completed", {
-        reason: `acp_error:${acpResolution.error.code.toLowerCase()}`,
+        reason: `acp_error:${normalizeLowercaseStringOrEmpty(acpResolution.error.code)}`,
       });
       params.markIdle("message_completed");
       return { queuedFinal: delivered, counts };
@@ -505,7 +505,7 @@ export async function tryDispatchAcpReply(params: {
       `acp-dispatch: session=${sessionKey} outcome=error code=${acpError.code} latencyMs=${Date.now() - acpDispatchStartedAt} queueDepth=${acpStats.turns.queueDepth} activeRuntimes=${acpStats.runtimeCache.activeSessions}`,
     );
     params.recordProcessed("completed", {
-      reason: `acp_error:${acpError.code.toLowerCase()}`,
+      reason: `acp_error:${normalizeLowercaseStringOrEmpty(acpError.code)}`,
     });
     params.markIdle("message_completed");
     return { queuedFinal, counts };

src/auto-reply/reply/dispatch-from-config.ts

@@ -37,6 +37,7 @@ import {
 } from "../../plugins/conversation-binding.js";
 import { getGlobalHookRunner, getGlobalPluginRegistry } from "../../plugins/hook-runner-global.js";
 import { resolveSendPolicy } from "../../sessions/send-policy.js";
+import { normalizeLowercaseStringOrEmpty } from "../../shared/string-coerce.js";
 import {
   normalizeOptionalLowercaseString,
   normalizeOptionalString,
@@ -205,7 +206,7 @@ export async function dispatchReplyFromConfig(params: {
 }): Promise<DispatchFromConfigResult> {
   const { ctx, cfg, dispatcher } = params;
   const diagnosticsEnabled = isDiagnosticsEnabled(cfg);
-  const channel = String(ctx.Surface ?? ctx.Provider ?? "unknown").toLowerCase();
+  const channel = normalizeLowercaseStringOrEmpty(String(ctx.Surface ?? ctx.Provider ?? "unknown"));
   const chatId = ctx.To ?? ctx.From;
   const messageId = ctx.MessageSid ?? ctx.MessageSidFirst ?? ctx.MessageSidLast;
   const sessionKey = ctx.SessionKey;

src/auto-reply/reply/get-reply-directives.ts

@@ -8,7 +8,10 @@ import type { SkillCommandSpec } from "../../agents/skills.js";
 import type { OpenClawConfig } from "../../config/config.js";
 import type { SessionEntry } from "../../config/sessions.js";
 import { normalizeAgentId } from "../../routing/session-key.js";
-import { normalizeOptionalString } from "../../shared/string-coerce.js";
+import {
+  normalizeLowercaseStringOrEmpty,
+  normalizeOptionalString,
+} from "../../shared/string-coerce.js";
 import { shouldHandleTextCommands } from "../commands-text-routing.js";
 import type { MsgContext, TemplateContext } from "../templating.js";
 import type { ElevatedLevel, ReasoningLevel, ThinkLevel, VerboseLevel } from "../thinking.js";
@@ -83,7 +86,7 @@ function resolveConfiguredDirectiveAliases(params: {
   return Object.values(params.cfg.agents?.defaults?.models ?? {})
     .map((entry) => normalizeOptionalString(entry.alias))
     .filter((alias): alias is string => Boolean(alias))
-    .filter((alias) => !params.reservedCommands.has(alias.toLowerCase()));
+    .filter((alias) => !params.reservedCommands.has(normalizeLowercaseStringOrEmpty(alias)));
 }
 
 export type ReplyDirectiveContinuation = {
@@ -242,7 +245,7 @@ export async function resolveReplyDirectives(params: {
     const { listChatCommands } = await loadCommandsRegistry();
     for (const chatCommand of listChatCommands()) {
       for (const alias of chatCommand.textAliases) {
-        reservedCommands.add(alias.replace(/^\//, "").toLowerCase());
+        reservedCommands.add(normalizeLowercaseStringOrEmpty(alias.replace(/^\//, "")));
       }
     }
   }
@@ -265,11 +268,11 @@ export async function resolveReplyDirectives(params: {
         })
       : [];
   for (const command of skillCommands) {
-    reservedCommands.add(command.name.toLowerCase());
+    reservedCommands.add(normalizeLowercaseStringOrEmpty(command.name));
   }
 
   const configuredAliases = rawAliases.filter(
-    (alias) => !reservedCommands.has(alias.toLowerCase()),
+    (alias) => !reservedCommands.has(normalizeLowercaseStringOrEmpty(alias)),
   );
   const allowStatusDirective = allowTextCommands && command.isAuthorizedSender;
   let parsedDirectives = parseInlineDirectives(commandText, {
@@ -379,10 +382,11 @@ export async function resolveReplyDirectives(params: {
   sessionCtx.Body = cleanedBody;
   sessionCtx.BodyStripped = cleanedBody;
 
-  const messageProviderKey =
-    normalizeOptionalString(sessionCtx.Provider)?.toLowerCase() ??
-    normalizeOptionalString(ctx.Provider)?.toLowerCase() ??
-    "";
+  const messageProviderKey = normalizeOptionalString(sessionCtx.Provider)
+    ? normalizeLowercaseStringOrEmpty(sessionCtx.Provider)
+    : normalizeOptionalString(ctx.Provider)
+      ? normalizeLowercaseStringOrEmpty(ctx.Provider)
+      : "";
   const elevated = resolveElevatedPermissions({
     cfg,
     agentId,
@@ -526,7 +530,7 @@ export async function resolveReplyDirectives(params: {
   const isModelListAlias =
     directives.hasModelDirective &&
     ["status", "list"].includes(
-      normalizeOptionalString(directives.rawModelDirective)?.toLowerCase() ?? "",
+      normalizeLowercaseStringOrEmpty(normalizeOptionalString(directives.rawModelDirective)),
     );
   const effectiveModelDirective = isModelListAlias ? undefined : directives.rawModelDirective;
 

src/auto-reply/reply/mentions.ts

@@ -5,6 +5,7 @@ import type { OpenClawConfig } from "../../config/config.js";
 import { createSubsystemLogger } from "../../logging/subsystem.js";
 import { compileConfigRegexes, type ConfigRegexRejectReason } from "../../security/config-regex.js";
 import {
+  normalizeLowercaseStringOrEmpty,
   normalizeOptionalLowercaseString,
   normalizeOptionalString,
 } from "../../shared/string-coerce.js";
@@ -133,7 +134,9 @@ export function buildMentionRegexes(cfg: OpenClawConfig | undefined, agentId?: s
 }
 
 export function normalizeMentionText(text: string): string {
-  return (text ?? "").replace(/[\u200b-\u200f\u202a-\u202e\u2060-\u206f]/g, "").toLowerCase();
+  return normalizeLowercaseStringOrEmpty(
+    (text ?? "").replace(/[\u200b-\u200f\u202a-\u202e\u2060-\u206f]/g, ""),
+  );
 }
 
 export function matchesMentionPatterns(text: string, mentionRegexes: RegExp[]): boolean {

src/auto-reply/reply/model-selection.ts

@@ -215,8 +215,8 @@ function scoreFuzzyMatch(params: {
   const provider = normalizeProviderId(params.provider);
   const model = params.model;
   const fragment = normalizeLowercaseStringOrEmpty(params.fragment);
-  const providerLower = provider.toLowerCase();
-  const modelLower = model.toLowerCase();
+  const providerLower = normalizeLowercaseStringOrEmpty(provider);
+  const modelLower = normalizeLowercaseStringOrEmpty(model);
   const haystack = `${providerLower}/${modelLower}`;
   const key = modelKey(provider, model);
 
@@ -262,7 +262,7 @@ function scoreFuzzyMatch(params: {
 
   const aliases = params.aliasIndex.byKey.get(key) ?? [];
   for (const alias of aliases) {
-    score += scoreFragment(alias.toLowerCase(), {
+    score += scoreFragment(normalizeLowercaseStringOrEmpty(alias), {
       exact: 140,
       starts: 90,
       includes: 60,
@@ -525,7 +525,7 @@ export function resolveModelDirectiveSelection(params: {
   const { raw, defaultProvider, defaultModel, aliasIndex, allowedModelKeys } = params;
 
   const rawTrimmed = raw.trim();
-  const rawLower = rawTrimmed.toLowerCase();
+  const rawLower = normalizeLowercaseStringOrEmpty(rawTrimmed);
 
   const pickAliasForKey = (provider: string, model: string): string | undefined =>
     aliasIndex.byKey.get(modelKey(provider, model))?.[0];

src/auto-reply/reply/post-compaction-context.ts

@@ -202,7 +202,9 @@ export function extractSections(
 
         if (!inSection) {
           // Check if this is our target section (case-insensitive)
-          if (headingText.toLowerCase() === name.toLowerCase()) {
+          if (
+            normalizeLowercaseStringOrEmpty(headingText) === normalizeLowercaseStringOrEmpty(name)
+          ) {
             inSection = true;
             sectionLevel = level;
             sectionLines = [line];

src/auto-reply/reply/reply-inline.ts

@@ -1,3 +1,4 @@
+import { normalizeLowercaseStringOrEmpty } from "../../shared/string-coerce.js";
 import { collapseInlineHorizontalWhitespace } from "./reply-inline-whitespace.js";
 
 const INLINE_SIMPLE_COMMAND_ALIASES = new Map<string, string>([
@@ -21,7 +22,7 @@ export function extractInlineSimpleCommand(body?: string): {
   if (!match || match.index === undefined) {
     return null;
   }
-  const alias = `/${match[1].toLowerCase()}`;
+  const alias = `/${normalizeLowercaseStringOrEmpty(match[1])}`;
   const command = INLINE_SIMPLE_COMMAND_ALIASES.get(alias);
   if (!command) {
     return null;

src/auto-reply/reply/response-prefix-template.ts

@@ -1,3 +1,5 @@
+import { normalizeLowercaseStringOrEmpty } from "../../shared/string-coerce.js";
+
 /**
  * Template interpolation for response prefix.
  *
@@ -44,7 +46,7 @@ export function resolveResponsePrefixTemplate(
   }
 
   return template.replace(TEMPLATE_VAR_PATTERN, (match, varName: string) => {
-    const normalizedVar = varName.toLowerCase();
+    const normalizedVar = normalizeLowercaseStringOrEmpty(varName);
 
     switch (normalizedVar) {
       case "model":

src/auto-reply/reply/session-delivery.ts

@@ -179,7 +179,7 @@ export function maybeRetireLegacyMainDeliveryRoute(params: {
   const canonicalMainSessionKey = buildAgentMainSessionKey({
     agentId: params.agentId,
     mainKey: params.mainKey,
-  }).toLowerCase();
+  });
   if (params.sessionKey === canonicalMainSessionKey) {
     return undefined;
   }

src/auto-reply/reply/session-system-events.ts

@@ -7,7 +7,10 @@ import {
   resolveTimezone,
 } from "../../infra/format-time/format-datetime.ts";
 import { drainSystemEventEntries } from "../../infra/system-events.js";
-import { normalizeOptionalString } from "../../shared/string-coerce.js";
+import {
+  normalizeLowercaseStringOrEmpty,
+  normalizeOptionalString,
+} from "../../shared/string-coerce.js";
 
 /** Drain queued system events, format as `System:` lines, return the block (or undefined). */
 export async function drainFormattedSystemEvents(params: {
@@ -21,7 +24,7 @@ export async function drainFormattedSystemEvents(params: {
     if (!trimmed) {
       return null;
     }
-    const lower = trimmed.toLowerCase();
+    const lower = normalizeLowercaseStringOrEmpty(trimmed);
     if (lower.includes("reason periodic")) {
       return null;
     }
@@ -44,7 +47,7 @@ export async function drainFormattedSystemEvents(params: {
     if (!raw) {
       return { mode: "local" as const };
     }
-    const lowered = raw.toLowerCase();
+    const lowered = normalizeLowercaseStringOrEmpty(raw);
     if (lowered === "utc" || lowered === "gmt") {
       return { mode: "utc" as const };
     }

src/auto-reply/reply/session.ts

@@ -34,6 +34,7 @@ import { getGlobalHookRunner } from "../../plugins/hook-runner-global.js";
 import type { PluginHookSessionEndReason } from "../../plugins/types.js";
 import { normalizeMainKey } from "../../routing/session-key.js";
 import {
+  normalizeLowercaseStringOrEmpty,
   normalizeOptionalLowercaseString,
   normalizeOptionalString,
 } from "../../shared/string-coerce.js";
@@ -318,8 +319,8 @@ export async function initSessionState(params: {
     : triggerBodyNormalized;
   // Reset triggers are configured as lowercased commands (e.g. "/new"), but users may type
   // "/NEW" etc. Match case-insensitively while keeping the original casing for any stripped body.
-  const trimmedBodyLower = trimmedBody.toLowerCase();
-  const strippedForResetLower = strippedForReset.toLowerCase();
+  const trimmedBodyLower = normalizeLowercaseStringOrEmpty(trimmedBody);
+  const strippedForResetLower = normalizeLowercaseStringOrEmpty(strippedForReset);
   let matchedResetTriggerLower: string | undefined;
 
   for (const trigger of resetTriggers) {
@@ -329,7 +330,7 @@ export async function initSessionState(params: {
     if (!resetAuthorized) {
       break;
     }
-    const triggerLower = trigger.toLowerCase();
+    const triggerLower = normalizeLowercaseStringOrEmpty(trigger);
     if (trimmedBodyLower === triggerLower || strippedForResetLower === triggerLower) {
       isNewSession = true;
       bodyStripped = "";

src/auto-reply/reply/subagents-utils.ts

@@ -1,5 +1,8 @@
 import type { SubagentRunRecord } from "../../agents/subagent-registry.js";
-import { normalizeOptionalString } from "../../shared/string-coerce.js";
+import {
+  normalizeLowercaseStringOrEmpty,
+  normalizeOptionalString,
+} from "../../shared/string-coerce.js";
 import { sanitizeTaskStatusText } from "../../tasks/task-status.js";
 import { truncateUtf16Safe } from "../../utils.js";
 
@@ -92,8 +95,10 @@ export function resolveSubagentTargetFromRuns(params: {
       ? { entry: bySessionKey }
       : { error: params.errors.unknownSession(trimmed) };
   }
-  const lowered = trimmed.toLowerCase();
-  const byExactLabel = deduped.filter((entry) => params.label(entry).toLowerCase() === lowered);
+  const lowered = normalizeLowercaseStringOrEmpty(trimmed);
+  const byExactLabel = deduped.filter(
+    (entry) => normalizeLowercaseStringOrEmpty(params.label(entry)) === lowered,
+  );
   if (byExactLabel.length === 1) {
     return { entry: byExactLabel[0] };
   }
@@ -101,7 +106,7 @@ export function resolveSubagentTargetFromRuns(params: {
     return { error: params.errors.ambiguousLabel(trimmed) };
   }
   const byLabelPrefix = deduped.filter((entry) =>
-    params.label(entry).toLowerCase().startsWith(lowered),
+    normalizeLowercaseStringOrEmpty(params.label(entry)).startsWith(lowered),
   );
   if (byLabelPrefix.length === 1) {
     return { entry: byLabelPrefix[0] };

src/auto-reply/skill-commands-base.ts

@@ -1,5 +1,8 @@
 import type { SkillCommandSpec } from "../agents/skills.js";
-import { normalizeOptionalLowercaseString } from "../shared/string-coerce.js";
+import {
+  normalizeLowercaseStringOrEmpty,
+  normalizeOptionalLowercaseString,
+} from "../shared/string-coerce.js";
 import { getChatCommands } from "./commands-registry.data.js";
 
 export function listReservedChatSlashCommandNames(extraNames: string[] = []): Set<string> {
@@ -13,7 +16,7 @@ export function listReservedChatSlashCommandNames(extraNames: string[] = []): Se
       if (!trimmed.startsWith("/")) {
         continue;
       }
-      reserved.add(trimmed.slice(1).toLowerCase());
+      reserved.add(normalizeLowercaseStringOrEmpty(trimmed.slice(1)));
     }
   }
   for (const name of extraNames) {

src/auto-reply/skill-commands.ts

@@ -9,7 +9,10 @@ import { buildWorkspaceSkillCommandSpecs, type SkillCommandSpec } from "../agent
 import type { OpenClawConfig } from "../config/config.js";
 import { logVerbose } from "../globals.js";
 import { getRemoteSkillEligibility } from "../infra/skills-remote.js";
-import { normalizeOptionalLowercaseString } from "../shared/string-coerce.js";
+import {
+  normalizeLowercaseStringOrEmpty,
+  normalizeOptionalLowercaseString,
+} from "../shared/string-coerce.js";
 import { listReservedChatSlashCommandNames } from "./skill-commands-base.js";
 export {
   listReservedChatSlashCommandNames,
@@ -119,7 +122,7 @@ export function listSkillCommandsForAgents(params: {
       reservedNames: used,
     });
     for (const command of commands) {
-      used.add(command.name.toLowerCase());
+      used.add(normalizeLowercaseStringOrEmpty(command.name));
       entries.push(command);
     }
   }

src/auto-reply/status.ts

@@ -31,7 +31,10 @@ import { resolveCommitHash } from "../infra/git-commit.js";
 import type { MediaUnderstandingDecision } from "../media-understanding/types.js";
 import { listPluginCommands } from "../plugins/commands.js";
 import { resolveAgentIdFromSessionKey } from "../routing/session-key.js";
-import { normalizeOptionalLowercaseString } from "../shared/string-coerce.js";
+import {
+  normalizeLowercaseStringOrEmpty,
+  normalizeOptionalLowercaseString,
+} from "../shared/string-coerce.js";
 import { resolveStatusTtsSnapshot } from "../tts/status-config.js";
 import {
   estimateUsageCost,
@@ -464,12 +467,11 @@ export function buildStatusMessage(args: StatusArgs): string {
       normalizeOptionalLowercaseString(runtimeModelRaw.slice(0, slashIndex)) ?? "";
     const fallbackMatchesRuntimeModel =
       initialFallbackState.active &&
-      runtimeModelRaw.toLowerCase() ===
-        String(entry?.fallbackNoticeActiveModel ?? "")
-          .trim()
-          .toLowerCase();
+      normalizeLowercaseStringOrEmpty(runtimeModelRaw) ===
+        normalizeLowercaseStringOrEmpty(String(entry?.fallbackNoticeActiveModel ?? "").trim());
     const runtimeMatchesSelectedModel =
-      runtimeModelRaw.toLowerCase() === (modelRefs.selected.label || "unknown").toLowerCase();
+      normalizeLowercaseStringOrEmpty(runtimeModelRaw) ===
+      normalizeLowercaseStringOrEmpty(modelRefs.selected.label || "unknown");
     // Legacy fallback sessions can persist provider-qualified runtime ids
     // without a separate modelProvider field. Preserve provider-aware lookup
     // when the stored slash id is the selected model or the active fallback
@@ -477,7 +479,7 @@ export function buildStatusMessage(args: StatusArgs): string {
     // slash ids.
     if (
       (fallbackMatchesRuntimeModel || runtimeMatchesSelectedModel) &&
-      embeddedProvider === activeProvider.toLowerCase()
+      embeddedProvider === normalizeLowercaseStringOrEmpty(activeProvider)
     ) {
       contextLookupProvider = activeProvider;
       contextLookupModel = activeModel;
@@ -998,9 +1000,12 @@ function formatCommandEntry(command: ChatCommandDefinition): string {
   const aliases = command.textAliases
     .map((alias) => alias.trim())
     .filter(Boolean)
-    .filter((alias) => alias.toLowerCase() !== primary.toLowerCase())
+    .filter(
+      (alias) =>
+        normalizeLowercaseStringOrEmpty(alias) !== normalizeLowercaseStringOrEmpty(primary),
+    )
     .filter((alias) => {
-      const key = alias.toLowerCase();
+      const key = normalizeLowercaseStringOrEmpty(alias);
       if (seen.has(key)) {
         return false;
       }
@@ -1079,7 +1084,7 @@ export function buildCommandsMessagePaginated(
   options?: CommandsMessageOptions,
 ): CommandsMessageResult {
   const page = Math.max(1, options?.page ?? 1);
-  const surface = options?.surface?.toLowerCase();
+  const surface = normalizeOptionalLowercaseString(options?.surface);
   const prefersPaginatedList =
     options?.forcePaginatedList === true ||
     Boolean(surface && getChannelPlugin(surface)?.commands?.buildCommandsListChannelData);

src/auto-reply/thinking.shared.ts

@@ -1,4 +1,7 @@
-import { normalizeOptionalLowercaseString } from "../shared/string-coerce.js";
+import {
+  normalizeLowercaseStringOrEmpty,
+  normalizeOptionalLowercaseString,
+} from "../shared/string-coerce.js";
 
 export type ThinkLevel = "off" | "minimal" | "low" | "medium" | "high" | "xhigh" | "adaptive";
 export type VerboseLevel = "off" | "on" | "full";
@@ -140,7 +143,7 @@ export function normalizeUsageDisplay(raw?: string | null): UsageDisplayLevel |
   if (!raw) {
     return undefined;
   }
-  const key = raw.toLowerCase();
+  const key = normalizeLowercaseStringOrEmpty(raw);
   if (["off", "false", "no", "0", "disable", "disabled"].includes(key)) {
     return "off";
   }
@@ -167,7 +170,7 @@ export function normalizeFastMode(raw?: string | boolean | null): boolean | unde
   if (!raw) {
     return undefined;
   }
-  const key = raw.toLowerCase();
+  const key = normalizeLowercaseStringOrEmpty(raw);
   if (["off", "false", "no", "0", "disable", "disabled", "normal"].includes(key)) {
     return false;
   }
@@ -181,7 +184,7 @@ export function normalizeElevatedLevel(raw?: string | null): ElevatedLevel | und
   if (!raw) {
     return undefined;
   }
-  const key = raw.toLowerCase();
+  const key = normalizeLowercaseStringOrEmpty(raw);
   if (["off", "false", "no", "0"].includes(key)) {
     return "off";
   }
@@ -211,7 +214,7 @@ export function normalizeReasoningLevel(raw?: string | null): ReasoningLevel | u
   if (!raw) {
     return undefined;
   }
-  const key = raw.toLowerCase();
+  const key = normalizeLowercaseStringOrEmpty(raw);
   if (["off", "false", "no", "0", "hide", "hidden", "disable", "disabled"].includes(key)) {
     return "off";
   }