feat(agent): enforce readonly execution mode

crates/agent-gateway/internal/handler/types.go

@@ -137,7 +137,7 @@ func normalizeTrimmedText(value string) string {
 func NormalizeExecutionMode(value string) string {
 	normalized := normalizeTrimmedText(value)
 	switch normalized {
-	case "tools", "agent-dev":
+	case "tools", "agent-dev", "readonly":
 		return normalized
 	default:
 		return "text"

crates/agent-gateway/internal/handler/types_test.go

@@ -11,6 +11,7 @@ func TestNormalizeExecutionMode(t *testing.T) {
 	cases := map[string]string{
 		"":          "text",
 		" text ":    "text",
+		"readonly":  "readonly",
 		"tools":     "tools",
 		"agent-dev": "agent-dev",
 		"unknown":   "text",

crates/agent-gateway/test/webui/web-settings.test.mjs

@@ -1466,3 +1466,15 @@ test("web right dock migrates the legacy tabs shape", () => {
   assert.deepEqual(project.tabOrder, ["sess-1", RIGHT_DOCK_TAB_IDS.fileTree]);
   assert.equal(project.activeTabId, "sess-1");
 });
+
+test("web settings preserve readonly execution mode", () => {
+  installWindow();
+  const defaults = settings.getDefaultSettings();
+  const normalized = settings.normalizeSettings({
+    system: { ...defaults.system, executionMode: "readonly" },
+  });
+
+  assert.equal(normalized.system.executionMode, "readonly");
+  assert.equal(settings.isAgentExecutionMode("readonly"), true);
+  assert.equal(settings.isReadOnlyExecutionMode("readonly"), true);
+});

crates/agent-gateway/web/src/app/GatewayApp.tsx

@@ -66,6 +66,7 @@ import { toModelValue } from "@/lib/providers/llm";
 import {
   type ChatRuntimeControls,
   DEFAULT_WORKSPACE_PROJECT_ID,
+  type ExecutionMode,
   findProviderModelConfig,
   getChatRuntimeReasoningLevelsForProvider,
   getNextTheme,
@@ -92,6 +93,7 @@ import {
   updateRightDockWidth,
   updateSkills,
   updateSshProjectHostIds,
+  updateSystem,
   type WorkspaceProject,
   workspaceProjectPathKey,
 } from "@/lib/settings";
@@ -3397,6 +3399,12 @@ export default function GatewayApp() {
       activeSelectedModel?.model,
     ],
   );
+  const handleExecutionModeChange = useCallback(
+    (executionMode: ExecutionMode) => {
+      setSettings((prev) => updateSystem(prev, { executionMode }));
+    },
+    [setSettings],
+  );
   const isAgentDevExecutionMode = isAgentDevMode(settings.system.executionMode);
 
   const modelOptions = useMemo(
@@ -4226,6 +4234,8 @@ export default function GatewayApp() {
                       workdir={displayedConversationWorkdir}
                       enabledSkills={enabledComposerSkills}
                       isAgentMode={isAgentMode}
+                      executionMode={settings.system.executionMode}
+                      onExecutionModeChange={handleExecutionModeChange}
                       chatRuntimeControls={chatRuntimeControlsForCurrentProvider}
                       reasoningOptions={chatRuntimeReasoningOptions}
                       thinkingAlwaysOn={chatRuntimeThinkingAlwaysOn}

crates/agent-gateway/web/src/i18n/config.ts

@@ -1029,13 +1029,18 @@ export const translations: Record<Locale, Record<string, string>> = {
     "settings.fontSizeLarge": "大",
     "settings.fontSizeXLarge": "特大",
     "settings.executionMode": "执行模式",
+    "settings.executionModeDesc": "选择新对话的默认权限；当前对话也可从输入框切换。",
     "settings.chatMode": "Chat 模式",
     "settings.chatModeDesc": "纯文本对话，模型只输出文本与 Markdown",
+    "settings.readonlyAgentMode": "只读 Agent",
+    "settings.readonlyAgentModeDesc": "可检查项目并委派只读代理，不修改文件或外部系统",
     "settings.agentMode": "Agent 模式",
     "settings.agentModeDesc": "允许调用工具，执行文件与命令行操作",
     "settings.agentDevMode": "Agent dev 模式",
     "settings.agentDevModeDesc":
       "与 Agent 模式一致，但会把当前对话的流式请求与返回逐行写入 ~/.liveagent/debug/<对话ID>.jsonl",
+    "settings.agentTrace": "Agent 调试记录",
+    "settings.agentTraceDesc": "仅在 Agent 模式启用时写入逐行 JSONL 调试记录",
     "settings.workdir": "项目文件夹",
     "settings.workdirRequired": "必填",
     "settings.workdirDesc": "选择这个项目的文件夹。文件工具会在所选项目目录内读写/搜索。",
@@ -2814,13 +2819,20 @@ export const translations: Record<Locale, Record<string, string>> = {
     "settings.fontSizeLarge": "Large",
     "settings.fontSizeXLarge": "Extra Large",
     "settings.executionMode": "Execution Mode",
+    "settings.executionModeDesc":
+      "Choose the default permission for new conversations. The current conversation can also be changed from the main composer.",
     "settings.chatMode": "Chat Mode",
     "settings.chatModeDesc": "Plain text conversation, model outputs text and Markdown only",
+    "settings.readonlyAgentMode": "Read-only Agent",
+    "settings.readonlyAgentModeDesc":
+      "Can inspect the project and delegate read-only agents without modifying files or external systems",
     "settings.agentMode": "Agent Mode",
     "settings.agentModeDesc": "Allows tool calls, file and command-line operations",
     "settings.agentDevMode": "Agent Dev Mode",
     "settings.agentDevModeDesc":
       "Same as Agent mode, but also writes each streaming request and response line-by-line to ~/.liveagent/debug/<conversationId>.jsonl",
+    "settings.agentTrace": "Agent debug trace",
+    "settings.agentTraceDesc": "Writes line-delimited JSONL traces only while Agent mode is active",
     "settings.workdir": "Project Folder",
     "settings.workdirRequired": "Required",
     "settings.workdirDesc":

crates/agent-gateway/web/src/lib/settings/index.ts

@@ -11,7 +11,7 @@ export type { SystemToolId } from "../tools/systemToolOptions";
 
 export type ProviderId = "codex" | "claude_code" | "gemini";
 
-export type ExecutionMode = "text" | "tools" | "agent-dev";
+export type ExecutionMode = "text" | "readonly" | "tools" | "agent-dev";
 
 export type CodexRequestFormat = "openai-completions" | "openai-responses";
 
@@ -408,6 +408,7 @@ export function getBuiltinCustomProviders(): CustomProvider[] {
 function normalizeExecutionMode(input: unknown): ExecutionMode {
   switch (input) {
     case "text":
+    case "readonly":
     case "tools":
     case "agent-dev":
       return input;
@@ -420,6 +421,10 @@ export function isAgentExecutionMode(mode: ExecutionMode): boolean {
   return mode !== "text";
 }
 
+export function isReadOnlyExecutionMode(mode: ExecutionMode): boolean {
+  return mode === "readonly";
+}
+
 export function isAgentDevMode(mode: ExecutionMode): boolean {
   return mode === "agent-dev";
 }

crates/agent-gateway/web/src/pages/chat/ChatComposerBar.tsx

@@ -24,13 +24,16 @@ import {
   Lightbulb,
   LightbulbOff,
   Loader2,
+  MessageSquare,
   Paperclip,
   Play,
   Send,
+  Shield,
   Sparkle,
   Square,
   SquarePen,
   Trash2,
+  Wrench,
   X,
 } from "../../components/icons";
 import { Button } from "../../components/ui/button";
@@ -47,6 +50,7 @@ import type { GitClient } from "../../lib/git/types";
 import {
   type ChatRuntimeControls,
   DEFAULT_CHAT_RUNTIME_CONTROLS,
+  type ExecutionMode,
   type ReasoningLevel,
 } from "../../lib/settings";
 import { cn } from "../../lib/shared/utils";
@@ -115,6 +119,8 @@ export const ChatComposerBar = memo(function ChatComposerBar(props: {
   workdir: string;
   enabledSkills: MentionComposerSkill[];
   isAgentMode: boolean;
+  executionMode: ExecutionMode;
+  onExecutionModeChange: (mode: ExecutionMode) => void;
   chatRuntimeControls: ChatRuntimeControls;
   reasoningOptions: ReasoningLevel[];
   thinkingAlwaysOn: boolean;
@@ -148,6 +154,8 @@ export const ChatComposerBar = memo(function ChatComposerBar(props: {
     workdir,
     enabledSkills,
     isAgentMode,
+    executionMode,
+    onExecutionModeChange,
     chatRuntimeControls,
     reasoningOptions,
     thinkingAlwaysOn,
@@ -187,7 +195,9 @@ export const ChatComposerBar = memo(function ChatComposerBar(props: {
   const [queueScrollbar, setQueueScrollbar] = useState<QueueScrollbarState>(
     DEFAULT_QUEUE_SCROLLBAR_STATE,
   );
-  const uploadDisabled = isInputDisabled || isUploadingFiles || !isAgentMode || !workdir;
+  const visibleExecutionMode = executionMode === "agent-dev" ? "tools" : executionMode;
+  const uploadDisabled =
+    isInputDisabled || isUploadingFiles || visibleExecutionMode !== "tools" || !workdir;
   const controlsDisabled = isInputDisabled;
   const hasSendableDraft = !composerIsEmpty || pendingUploadedFiles.length > 0;
   const thinkingSupported = reasoningOptions.length > 0;
@@ -213,6 +223,18 @@ export const ChatComposerBar = memo(function ChatComposerBar(props: {
     : t("chat.runtime.thinkingTooltip");
   const webSearchTooltip = t("chat.runtime.webSearchTooltip");
   const toggleQueueTooltip = queueCollapsed ? t("chat.queue.expand") : t("chat.queue.collapse");
+  const executionModes: Array<{
+    mode: "text" | "readonly" | "tools";
+    label: string;
+    icon: typeof MessageSquare;
+  }> = [
+    { mode: "text", label: t("settings.chatMode"), icon: MessageSquare },
+    { mode: "readonly", label: t("settings.readonlyAgentMode"), icon: Shield },
+    { mode: "tools", label: t("settings.agentMode"), icon: Wrench },
+  ];
+  const selectedExecutionMode =
+    executionModes.find((option) => option.mode === visibleExecutionMode) ?? executionModes[2];
+  const SelectedExecutionModeIcon = selectedExecutionMode.icon;
 
   const toggleQueueCollapsed = useCallback(() => {
     setQueueCollapsed((current) => !current);
@@ -620,6 +642,50 @@ export const ChatComposerBar = memo(function ChatComposerBar(props: {
 
           <div className="relative flex items-center justify-between gap-2 px-3 pb-2 pt-1">
             <div className="flex min-w-0 flex-1 items-center gap-1">
+              <Select
+                value={visibleExecutionMode}
+                onValueChange={(value) =>
+                  onExecutionModeChange(value as "text" | "readonly" | "tools")
+                }
+                disabled={controlsDisabled}
+              >
+                <SelectTrigger
+                  aria-label={`${t("settings.executionMode")}: ${selectedExecutionMode.label}`}
+                  title={selectedExecutionMode.label}
+                  className={cn(
+                    "mr-1 h-8 w-auto max-w-[7.5rem] shrink-0 gap-1 rounded-full border-black/[0.055] bg-white/45 px-2 py-0 text-xs font-medium shadow-[inset_0_1px_0_rgba(255,255,255,0.6)] outline-hidden transition-colors hover:bg-white/70 disabled:pointer-events-none dark:border-white/[0.08] dark:bg-white/[0.04] dark:hover:bg-white/[0.08] max-sm:mr-0 max-sm:w-8 max-sm:gap-0 max-sm:px-0 max-sm:[&_svg:last-child]:hidden [&_svg:last-child]:h-3 [&_svg:last-child]:w-3 [&_svg:last-child]:shrink-0 [&_svg:last-child]:opacity-45 [&_svg:last-child]:transition-transform [&[data-popup-open]_svg:last-child]:rotate-180",
+                    visibleExecutionMode === "readonly" &&
+                      "border-emerald-500/15 bg-emerald-50/70 text-emerald-700 hover:bg-emerald-50 dark:border-emerald-300/10 dark:bg-emerald-400/[0.10] dark:text-emerald-200 dark:hover:bg-emerald-400/[0.15]",
+                  )}
+                >
+                  <SelectValue>
+                    <span className="flex min-w-0 items-center gap-1.5">
+                      <SelectedExecutionModeIcon className="h-3.5 w-3.5 shrink-0" />
+                      <span className="truncate max-sm:hidden">{selectedExecutionMode.label}</span>
+                    </span>
+                  </SelectValue>
+                </SelectTrigger>
+                <SelectContent className="min-w-40 border-black/[0.08] bg-popover/95 shadow-xl backdrop-blur-xl dark:border-white/[0.10]">
+                  {executionModes.map((option) => {
+                    const Icon = option.icon;
+                    return (
+                      <SelectItem key={option.mode} value={option.mode} className="py-2 pr-8">
+                        <span className="flex items-center gap-2">
+                          <Icon
+                            className={cn(
+                              "h-4 w-4 text-muted-foreground",
+                              option.mode === "readonly" &&
+                                "text-emerald-600 dark:text-emerald-300",
+                            )}
+                          />
+                          <span>{option.label}</span>
+                        </span>
+                      </SelectItem>
+                    );
+                  })}
+                </SelectContent>
+              </Select>
+
               <RuntimeControlTooltip label={uploadTooltip}>
                 <button
                   type="button"