// biome-ignore-all assist/source/organizeImports: ANT-ONLY import markers must not be reordered
import { feature } from 'bun:bundle'
import { readFile, stat } from 'fs/promises'
import { dirname } from 'path'
import {
  downloadUserSettings,
  redownloadUserSettings,
} from 'src/services/settingsSync/index.js'
import { waitForRemoteManagedSettingsToLoad } from 'src/services/remoteManagedSettings/index.js'
import { StructuredIO } from 'src/cli/structuredIO.js'
import { RemoteIO } from 'src/cli/remoteIO.js'
import {
  type Command,
  formatDescriptionWithSource,
  getCommandName,
} from 'src/commands.js'
import { createStreamlinedTransformer } from 'src/utils/streamlinedTransform.js'
import { installStreamJsonStdoutGuard } from 'src/utils/streamJsonStdoutGuard.js'
import type { ToolPermissionContext } from 'src/Tool.js'
import type { ThinkingConfig } from 'src/utils/thinking.js'
import { assembleToolPool, filterToolsByDenyRules } from 'src/tools.js'
import uniqBy from 'lodash-es/uniqBy.js'
import { uniq } from 'src/utils/array.js'
import { mergeAndFilterTools } from 'src/utils/toolPool.js'
import {
  logEvent,
  type AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
} from 'src/services/analytics/index.js'
import { getFeatureValue_CACHED_MAY_BE_STALE } from 'src/services/analytics/growthbook.js'
import { logForDebugging } from 'src/utils/debug.js'
import {
  logForDiagnosticsNoPII,
  withDiagnosticsTiming,
} from 'src/utils/diagLogs.js'
import { toolMatchesName, type Tool, type Tools } from 'src/Tool.js'
import {
  type AgentDefinition,
  isBuiltInAgent,
  parseAgentsFromJson,
} from 'src/tools/AgentTool/loadAgentsDir.js'
import type { Message, NormalizedUserMessage } from 'src/types/message.js'
import type { QueuedCommand } from 'src/types/textInputTypes.js'
import {
  dequeue,
  dequeueAllMatching,
  enqueue,
  hasCommandsInQueue,
  peek,
  subscribeToCommandQueue,
  getCommandsByMaxPriority,
} from 'src/utils/messageQueueManager.js'
import { notifyCommandLifecycle } from 'src/utils/commandLifecycle.js'
import {
  getSessionState,
  notifySessionStateChanged,
  notifySessionMetadataChanged,
  setPermissionModeChangedListener,
  type RequiresActionDetails,
  type SessionExternalMetadata,
} from 'src/utils/sessionState.js'
import { externalMetadataToAppState } from 'src/state/onChangeAppState.js'
import { getInMemoryErrors, logError, logMCPDebug } from 'src/utils/log.js'
import {
  writeToStdout,
  registerProcessOutputErrorHandlers,
} from 'src/utils/process.js'
import type { Stream } from 'src/utils/stream.js'
import { EMPTY_USAGE } from 'src/services/api/logging.js'
import {
  loadConversationForResume,
  type TurnInterruptionState,
} from 'src/utils/conversationRecovery.js'
import type {
  MCPServerConnection,
  McpSdkServerConfig,
  ScopedMcpServerConfig,
} from 'src/services/mcp/types.js'
import {
  ChannelMessageNotificationSchema,
  gateChannelServer,
  wrapChannelMessage,
  findChannelEntry,
} from 'src/services/mcp/channelNotification.js'
import {
  isChannelAllowlisted,
  isChannelsEnabled,
} from 'src/services/mcp/channelAllowlist.js'
import { parsePluginIdentifier } from 'src/utils/plugins/pluginIdentifier.js'
import { validateUuid } from 'src/utils/uuid.js'
import { fromArray } from 'src/utils/generators.js'
import { ask } from 'src/QueryEngine.js'
import type { PermissionPromptTool } from 'src/utils/queryHelpers.js'
import {
  createFileStateCacheWithSizeLimit,
  mergeFileStateCaches,
  READ_FILE_STATE_CACHE_SIZE,
} from 'src/utils/fileStateCache.js'
import { expandPath } from 'src/utils/path.js'
import { extractReadFilesFromMessages } from 'src/utils/queryHelpers.js'
import { registerHookEventHandler } from 'src/utils/hooks/hookEvents.js'
import { executeFilePersistence } from 'src/utils/filePersistence/filePersistence.js'
import { finalizePendingAsyncHooks } from 'src/utils/hooks/AsyncHookRegistry.js'
import {
  gracefulShutdown,
  gracefulShutdownSync,
  isShuttingDown,
} from 'src/utils/gracefulShutdown.js'
import { registerCleanup } from 'src/utils/cleanupRegistry.js'
import { createIdleTimeoutManager } from 'src/utils/idleTimeout.js'
import type {
  SDKStatus,
  ModelInfo,
  SDKMessage,
  SDKUserMessage,
  SDKUserMessageReplay,
  PermissionResult,
  McpServerConfigForProcessTransport,
  McpServerStatus,
  RewindFilesResult,
} from 'src/entrypoints/agentSdkTypes.js'
import type {
  StdoutMessage,
  SDKControlInitializeRequest,
  SDKControlInitializeResponse,
  SDKControlRequest,
  SDKControlResponse,
  SDKControlMcpSetServersResponse,
  SDKControlReloadPluginsResponse,
} from 'src/entrypoints/sdk/controlTypes.js'
import type { PermissionMode } from '@anthropic-ai/claude-agent-sdk'
import type { PermissionMode as InternalPermissionMode } from 'src/types/permissions.js'
import { cwd } from 'process'
import { getCwd } from 'src/utils/cwd.js'
import omit from 'lodash-es/omit.js'
import reject from 'lodash-es/reject.js'
import { isPolicyAllowed } from 'src/services/policyLimits/index.js'
import type { ReplBridgeHandle } from 'src/bridge/replBridge.js'
import { getRemoteSessionUrl } from 'src/constants/product.js'
import { buildBridgeConnectUrl } from 'src/bridge/bridgeStatusUtil.js'
import { extractInboundMessageFields } from 'src/bridge/inboundMessages.js'
import { resolveAndPrepend } from 'src/bridge/inboundAttachments.js'
import type { CanUseToolFn } from 'src/hooks/useCanUseTool.js'
import { hasPermissionsToUseTool } from 'src/utils/permissions/permissions.js'
import { safeParseJSON } from 'src/utils/json.js'
import {
  outputSchema as permissionToolOutputSchema,
  permissionPromptToolResultToPermissionDecision,
} from 'src/utils/permissions/PermissionPromptToolResultSchema.js'
import { createAbortController } from 'src/utils/abortController.js'
import { createCombinedAbortSignal } from 'src/utils/combinedAbortSignal.js'
import { generateSessionTitle } from 'src/utils/sessionTitle.js'
import { buildSideQuestionFallbackParams } from 'src/utils/queryContext.js'
import { runSideQuestion } from 'src/utils/sideQuestion.js'
import {
  processSessionStartHooks,
  processSetupHooks,
  takeInitialUserMessage,
} from 'src/utils/sessionStart.js'
import {
  DEFAULT_OUTPUT_STYLE_NAME,
  getAllOutputStyles,
} from 'src/constants/outputStyles.js'
import { TEAMMATE_MESSAGE_TAG, TICK_TAG } from 'src/constants/xml.js'
import {
  getSettings_DEPRECATED,
  getSettingsWithSources,
} from 'src/utils/settings/settings.js'
import { settingsChangeDetector } from 'src/utils/settings/changeDetector.js'
import { applySettingsChange } from 'src/utils/settings/applySettingsChange.js'
import {
  isFastModeAvailable,
  isFastModeEnabled,
  isFastModeSupportedByModel,
  getFastModeState,
} from 'src/utils/fastMode.js'
import {
  isAutoModeGateEnabled,
  getAutoModeUnavailableNotification,
  getAutoModeUnavailableReason,
  isBypassPermissionsModeDisabled,
  transitionPermissionMode,
} from 'src/utils/permissions/permissionSetup.js'
import {
  tryGenerateSuggestion,
  logSuggestionOutcome,
  logSuggestionSuppressed,
  type PromptVariant,
} from 'src/services/PromptSuggestion/promptSuggestion.js'
import { getLastCacheSafeParams } from 'src/utils/forkedAgent.js'
import { getAccountInformation } from 'src/utils/auth.js'
import { OAuthService } from 'src/services/oauth/index.js'
import { installOAuthTokens } from 'src/cli/handlers/auth.js'
import { getAPIProvider } from 'src/utils/model/providers.js'
import type { HookCallbackMatcher } from 'src/types/hooks.js'
import { AwsAuthStatusManager } from 'src/utils/awsAuthStatusManager.js'
import type { HookEvent } from 'src/entrypoints/agentSdkTypes.js'
import {
  registerHookCallbacks,
  setInitJsonSchema,
  getInitJsonSchema,
  setSdkAgentProgressSummariesEnabled,
} from 'src/bootstrap/state.js'
import { createSyntheticOutputTool } from 'src/tools/SyntheticOutputTool/SyntheticOutputTool.js'
import { parseSessionIdentifier } from 'src/utils/sessionUrl.js'
import {
  hydrateRemoteSession,
  hydrateFromCCRv2InternalEvents,
  resetSessionFilePointer,
  doesMessageExistInSession,
  findUnresolvedToolUse,
  recordAttributionSnapshot,
  saveAgentSetting,
  saveMode,
  saveAiGeneratedTitle,
  restoreSessionMetadata,
} from 'src/utils/sessionStorage.js'
import { incrementPromptCount } from 'src/utils/commitAttribution.js'
import {
  setupSdkMcpClients,
  connectToServer,
  clearServerCache,
  fetchToolsForClient,
  areMcpConfigsEqual,
  reconnectMcpServerImpl,
} from 'src/services/mcp/client.js'
import {
  filterMcpServersByPolicy,
  getMcpConfigByName,
  isMcpServerDisabled,
  setMcpServerEnabled,
} from 'src/services/mcp/config.js'
import {
  performMCPOAuthFlow,
  revokeServerTokens,
} from 'src/services/mcp/auth.js'
import {
  runElicitationHooks,
  runElicitationResultHooks,
} from 'src/services/mcp/elicitationHandler.js'
import { executeNotificationHooks } from 'src/utils/hooks.js'
import {
  ElicitRequestSchema,
  ElicitationCompleteNotificationSchema,
} from '@modelcontextprotocol/sdk/types.js'
import { getMcpPrefix } from 'src/services/mcp/mcpStringUtils.js'
import {
  commandBelongsToServer,
  filterToolsByServer,
} from 'src/services/mcp/utils.js'
import { setupVscodeSdkMcp } from 'src/services/mcp/vscodeSdkMcp.js'
import { getAllMcpConfigs } from 'src/services/mcp/config.js'
import {
  isQualifiedForGrove,
  checkGroveForNonInteractive,
} from 'src/services/api/grove.js'
import {
  toInternalMessages,
  toSDKRateLimitInfo,
} from 'src/utils/messages/mappers.js'
import { createModelSwitchBreadcrumbs } from 'src/utils/messages.js'
import { collectContextData } from 'src/commands/context/context-noninteractive.js'
import { LOCAL_COMMAND_STDOUT_TAG } from 'src/constants/xml.js'
import {
  statusListeners,
  type ClaudeAILimits,
} from 'src/services/claudeAiLimits.js'
import {
  getDefaultMainLoopModel,
  getMainLoopModel,
  modelDisplayString,
  parseUserSpecifiedModel,
} from 'src/utils/model/model.js'
import { getModelOptions } from 'src/utils/model/modelOptions.js'
import {
  modelSupportsEffort,
  modelSupportsMaxEffort,
  EFFORT_LEVELS,
  resolveAppliedEffort,
} from 'src/utils/effort.js'
import { modelSupportsAdaptiveThinking } from 'src/utils/thinking.js'
import { modelSupportsAutoMode } from 'src/utils/betas.js'
import { ensureModelStringsInitialized } from 'src/utils/model/modelStrings.js'
import {
  getSessionId,
  setMainLoopModelOverride,
  setMainThreadAgentType,
  switchSession,
  isSessionPersistenceDisabled,
  getIsRemoteMode,
  getFlagSettingsInline,
  setFlagSettingsInline,
  getMainThreadAgentType,
  getAllowedChannels,
  setAllowedChannels,
  type ChannelEntry,
} from 'src/bootstrap/state.js'
import { runWithWorkload, WORKLOAD_CRON } from 'src/utils/workloadContext.js'
import type { UUID } from 'crypto'
import { randomUUID } from 'crypto'
import type { ContentBlockParam } from '@anthropic-ai/sdk/resources/messages.mjs'
import type { AppState } from 'src/state/AppStateStore.js'
import {
  fileHistoryRewind,
  fileHistoryCanRestore,
  fileHistoryEnabled,
  fileHistoryGetDiffStats,
} from 'src/utils/fileHistory.js'
import {
  restoreAgentFromSession,
  restoreSessionStateFromLog,
} from 'src/utils/sessionRestore.js'
import { SandboxManager } from 'src/utils/sandbox/sandbox-adapter.js'
import {
  headlessProfilerStartTurn,
  headlessProfilerCheckpoint,
  logHeadlessProfilerTurn,
} from 'src/utils/headlessProfiler.js'
import {
  startQueryProfile,
  logQueryProfileReport,
} from 'src/utils/queryProfiler.js'
import { asSessionId } from 'src/types/ids.js'
import { jsonStringify } from '../utils/slowOperations.js'
import { skillChangeDetector } from '../utils/skills/skillChangeDetector.js'
import { getCommands, clearCommandsCache } from '../commands.js'
import {
  isBareMode,
  isEnvTruthy,
  isEnvDefinedFalsy,
} from '../utils/envUtils.js'
import { installPluginsForHeadless } from '../utils/plugins/headlessPluginInstall.js'
import { refreshActivePlugins } from '../utils/plugins/refresh.js'
import { loadAllPluginsCacheOnly } from '../utils/plugins/pluginLoader.js'
import {
  isTeamLead,
  hasActiveInProcessTeammates,
  hasWorkingInProcessTeammates,
  waitForTeammatesToBecomeIdle,
} from '../utils/teammate.js'
import {
  readUnreadMessages,
  markMessagesAsRead,
  isShutdownApproved,
} from '../utils/teammateMailbox.js'
import { removeTeammateFromTeamFile } from '../utils/swarm/teamHelpers.js'
import { unassignTeammateTasks } from '../utils/tasks.js'
import { getRunningTasks } from '../utils/task/framework.js'
import { isBackgroundTask } from '../tasks/types.js'
import { stopTask } from '../tasks/stopTask.js'
import { drainSdkEvents } from '../utils/sdkEventQueue.js'
import { initializeGrowthBook } from '../services/analytics/growthbook.js'
import { errorMessage, toError } from '../utils/errors.js'
import { sleep } from '../utils/sleep.js'
import { isExtractModeActive } from '../memdir/paths.js'

// Dead code elimination: conditional imports
/* eslint-disable @typescript-eslint/no-require-imports */
const coordinatorModeModule = feature('COORDINATOR_MODE')
  ? (require('../coordinator/coordinatorMode.js') as typeof import('../coordinator/coordinatorMode.js'))
  : null
const proactiveModule =
  feature('PROACTIVE') || feature('KAIROS')
    ? (require('../proactive/index.js') as typeof import('../proactive/index.js'))
    : null
const cronSchedulerModule = feature('AGENT_TRIGGERS')
  ? (require('../utils/cronScheduler.js') as typeof import('../utils/cronScheduler.js'))
  : null
const cronJitterConfigModule = feature('AGENT_TRIGGERS')
  ? (require('../utils/cronJitterConfig.js') as typeof import('../utils/cronJitterConfig.js'))
  : null
const cronGate = feature('AGENT_TRIGGERS')
  ? (require('../tools/ScheduleCronTool/prompt.js') as typeof import('../tools/ScheduleCronTool/prompt.js'))
  : null
const extractMemoriesModule = feature('EXTRACT_MEMORIES')
  ? (require('../services/extractMemories/extractMemories.js') as typeof import('../services/extractMemories/extractMemories.js'))
  : null
/* eslint-enable @typescript-eslint/no-require-imports */

const SHUTDOWN_TEAM_PROMPT = `<system-reminder>
You are running in non-interactive mode and cannot return a response to the user until your team is shut down.

You MUST shut down your team before preparing your final response:
1. Use requestShutdown to ask each team member to shut down gracefully
2. Wait for shutdown approvals
3. Use the cleanup operation to clean up the team
4. Only then provide your final response to the user

The user cannot receive your response until the team is completely shut down.
</system-reminder>

Shut down your team and prepare your final response for the user.`

// Track message UUIDs received during the current session runtime
const MAX_RECEIVED_UUIDS = 10_000
const receivedMessageUuids = new Set<UUID>()
const receivedMessageUuidsOrder: UUID[] = []

function trackReceivedMessageUuid(uuid: UUID): boolean {
  if (receivedMessageUuids.has(uuid)) {
    return false // duplicate
  }
  receivedMessageUuids.add(uuid)
  receivedMessageUuidsOrder.push(uuid)
  // Evict oldest entries when at capacity
  if (receivedMessageUuidsOrder.length > MAX_RECEIVED_UUIDS) {
    const toEvict = receivedMessageUuidsOrder.splice(
      0,
      receivedMessageUuidsOrder.length - MAX_RECEIVED_UUIDS,
    )
    for (const old of toEvict) {
      receivedMessageUuids.delete(old)
    }
  }
  return true // new UUID
}

type PromptValue = string | ContentBlockParam[]

function toBlocks(v: PromptValue): ContentBlockParam[] {
  return typeof v === 'string' ? [{ type: 'text', text: v }] : v
}

/**
 * Join prompt values from multiple queued commands into one. Strings are
 * newline-joined; if any value is a block array, all values are normalized
 * to blocks and concatenated.
 */
export function joinPromptValues(values: PromptValue[]): PromptValue {
  if (values.length === 1) return values[0]!
  if (values.every(v => typeof v === 'string')) {
    return values.join('\n')
  }
  return values.flatMap(toBlocks)
}

/**
 * Whether `next` can be batched into the same ask() call as `head`. Only
 * prompt-mode commands batch, and only when the workload tag matches (so the
 * combined turn is attributed correctly) and the isMeta flag matches (so a
 * proactive tick can't merge into a user prompt and lose its hidden-in-
 * transcript marking when the head is spread over the merged command).
 */
export function canBatchWith(
  head: QueuedCommand,
  next: QueuedCommand | undefined,
): boolean {
  return (
    next !== undefined &&
    next.mode === 'prompt' &&
    next.workload === head.workload &&
    next.isMeta === head.isMeta
  )
}

export async function runHeadless(
  inputPrompt: string | AsyncIterable<string>,
  getAppState: () => AppState,
  setAppState: (f: (prev: AppState) => AppState) => void,
  commands: Command[],
  tools: Tools,
  sdkMcpConfigs: Record<string, McpSdkServerConfig>,
  agents: AgentDefinition[],
  options: {
    continue: boolean | undefined
    resume: string | boolean | undefined
    resumeSessionAt: string | undefined
    verbose: boolean | undefined
    outputFormat: string | undefined
    jsonSchema: Record<string, unknown> | undefined
    permissionPromptToolName: string | undefined
    allowedTools: string[] | undefined
    thinkingConfig: ThinkingConfig | undefined
    maxTurns: number | undefined
    maxBudgetUsd: number | undefined
    taskBudget: { total: number } | undefined
    systemPrompt: string | undefined
    appendSystemPrompt: string | undefined
    userSpecifiedModel: string | undefined
    fallbackModel: string | undefined
    teleport: string | true | null | undefined
    sdkUrl: string | undefined
    replayUserMessages: boolean | undefined
    includePartialMessages: boolean | undefined
    forkSession: boolean | undefined
    rewindFiles: string | undefined
    enableAuthStatus: boolean | undefined
    agent: string | undefined
    workload: string | undefined
    setupTrigger?: 'init' | 'maintenance' | undefined
    sessionStartHooksPromise?: ReturnType<typeof processSessionStartHooks>
    setSDKStatus?: (status: SDKStatus) => void
  },
): Promise<void> {
  if (
    process.env.USER_TYPE === 'ant' &&
    isEnvTruthy(process.env.CLAUDE_CODE_EXIT_AFTER_FIRST_RENDER)
  ) {
    process.stderr.write(
      `\nStartup time: ${Math.round(process.uptime() * 1000)}ms\n`,
    )
    // eslint-disable-next-line custom-rules/no-process-exit
    process.exit(0)
  }

  // Fire user settings download now so it overlaps with the MCP/tool setup
  // below. Managed settings already started in main.tsx preAction; this gives
  // user settings a similar head start. The cached promise is joined in
  // installPluginsAndApplyMcpInBackground before plugin install reads
  // enabledPlugins.
  if (
    feature('DOWNLOAD_USER_SETTINGS') &&
    (isEnvTruthy(process.env.CLAUDE_CODE_REMOTE) || getIsRemoteMode())
  ) {
    void downloadUserSettings()
  }

  // In headless mode there is no React tree, so the useSettingsChange hook
  // never runs. Subscribe directly so that settings changes (including
  // managed-settings / policy updates) are fully applied.
  settingsChangeDetector.subscribe(source => {
    applySettingsChange(source, setAppState)

    // In headless mode, also sync the denormalized fastMode field from
    // settings. The TUI manages fastMode via the UI so it skips this.
    if (isFastModeEnabled()) {
      setAppState(prev => {
        const s = prev.settings as Record<string, unknown>
        const fastMode = s.fastMode === true && !s.fastModePerSessionOptIn
        return { ...prev, fastMode }
      })
    }
  })

  // Proactive activation is now handled in main.tsx before getTools() so
  // SleepTool passes isEnabled() filtering. This fallback covers the case
  // where CLAUDE_CODE_PROACTIVE is set but main.tsx's check didn't fire
  // (e.g. env was injected by the SDK transport after argv parsing).
  if (
    (feature('PROACTIVE') || feature('KAIROS')) &&
    proactiveModule &&
    !proactiveModule.isProactiveActive() &&
    isEnvTruthy(process.env.CLAUDE_CODE_PROACTIVE)
  ) {
    proactiveModule.activateProactive('command')
  }

  // Headless sessions can run for a long time, but forcing a full GC every
  // second burns CPU even when memory is healthy. Poll less often and only
  // collect aggressively once the heap is actually elevated, unless the user
  // explicitly opts into the old behavior for profiling/debugging.
  if (typeof Bun !== 'undefined') {
    const GC_INTERVAL_MS = 15_000
    const GC_HEAP_THRESHOLD_BYTES = 768 * 1024 * 1024
    const gcTimer = setInterval(() => {
      if (
        isEnvTruthy(process.env.CLAUDE_CODE_FORCE_PERIODIC_GC) ||
        process.memoryUsage().heapUsed >= GC_HEAP_THRESHOLD_BYTES
      ) {
        Bun.gc(true)
      }
    }, GC_INTERVAL_MS)
    gcTimer.unref()
  }

  // Start headless profiler for first turn
  headlessProfilerStartTurn()
  headlessProfilerCheckpoint('runHeadless_entry')

  // Check Grove requirements for non-interactive consumer subscribers
  if (await isQualifiedForGrove()) {
    await checkGroveForNonInteractive()
  }
  headlessProfilerCheckpoint('after_grove_check')

  // Initialize GrowthBook so feature flags take effect in headless mode.
  // Without this, the disk cache is empty and all flags fall back to defaults.
  void initializeGrowthBook()

  if (options.resumeSessionAt && !options.resume) {
    process.stderr.write(`Error: --resume-session-at requires --resume\n`)
    gracefulShutdownSync(1)
    return
  }

  if (options.rewindFiles && !options.resume) {
    process.stderr.write(`Error: --rewind-files requires --resume\n`)
    gracefulShutdownSync(1)
    return
  }

  if (options.rewindFiles && inputPrompt) {
    process.stderr.write(
      `Error: --rewind-files is a standalone operation and cannot be used with a prompt\n`,
    )
    gracefulShutdownSync(1)
    return
  }

  const structuredIO = getStructuredIO(inputPrompt, options)

  // When emitting NDJSON for SDK clients, any stray write to stdout (debug
  // prints, dependency console.log, library banners) breaks the client's
  // line-by-line JSON parser. Install a guard that diverts non-JSON lines to
  // stderr so the stream stays clean. Must run before the first
  // structuredIO.write below.
  if (options.outputFormat === 'stream-json') {
    installStreamJsonStdoutGuard()
  }

  // #34044: if user explicitly set sandbox.enabled=true but deps are missing,
  // isSandboxingEnabled() returns false silently. Surface the reason so users
  // know their security config isn't being enforced.
  const sandboxUnavailableReason = SandboxManager.getSandboxUnavailableReason()
  if (sandboxUnavailableReason) {
    if (SandboxManager.isSandboxRequired()) {
      process.stderr.write(
        `\nError: sandbox required but unavailable: ${sandboxUnavailableReason}\n` +
          `  sandbox.failIfUnavailable is set — refusing to start without a working sandbox.\n\n`,
      )
      gracefulShutdownSync(1)
      return
    }
    process.stderr.write(
      `\n⚠ Sandbox disabled: ${sandboxUnavailableReason}\n` +
        `  Commands will run WITHOUT sandboxing. Network and filesystem restrictions will NOT be enforced.\n\n`,
    )
  } else if (SandboxManager.isSandboxingEnabled()) {
    // Initialize sandbox with a callback that forwards network permission
    // requests to the SDK host via the can_use_tool control_request protocol.
    // This must happen after structuredIO is created so we can send requests.
    try {
      await SandboxManager.initialize(structuredIO.createSandboxAskCallback())
    } catch (err) {
      process.stderr.write(`\n❌ Sandbox Error: ${errorMessage(err)}\n`)
      gracefulShutdownSync(1, 'other')
      return
    }
  }

  if (options.outputFormat === 'stream-json' && options.verbose) {
    registerHookEventHandler(event => {
      const message: StdoutMessage = (() => {
        switch (event.type) {
          case 'started':
            return {
              type: 'system' as const,
              subtype: 'hook_started' as const,
              hook_id: event.hookId,
              hook_name: event.hookName,
              hook_event: event.hookEvent,
              uuid: randomUUID(),
              session_id: getSessionId(),
            }
          case 'progress':
            return {
              type: 'system' as const,
              subtype: 'hook_progress' as const,
              hook_id: event.hookId,
              hook_name: event.hookName,
              hook_event: event.hookEvent,
              stdout: event.stdout,
              stderr: event.stderr,
              output: event.output,
              uuid: randomUUID(),
              session_id: getSessionId(),
            }
          case 'response':
            return {
              type: 'system' as const,
              subtype: 'hook_response' as const,
              hook_id: event.hookId,
              hook_name: event.hookName,
              hook_event: event.hookEvent,
              output: event.output,
              stdout: event.stdout,
              stderr: event.stderr,
              exit_code: event.exitCode,
              outcome: event.outcome,
              uuid: randomUUID(),
              session_id: getSessionId(),
            }
        }
      })()
      void structuredIO.write(message)
    })
  }

  if (options.setupTrigger) {
    await processSetupHooks(options.setupTrigger)
  }

  headlessProfilerCheckpoint('before_loadInitialMessages')
  const appState = getAppState()
  const {
    messages: initialMessages,
    turnInterruptionState,
    agentSetting: resumedAgentSetting,
  } = await loadInitialMessages(setAppState, {
    continue: options.continue,
    teleport: options.teleport,
    resume: options.resume,
    resumeSessionAt: options.resumeSessionAt,
    forkSession: options.forkSession,
    outputFormat: options.outputFormat,
    sessionStartHooksPromise: options.sessionStartHooksPromise,
    restoredWorkerState: structuredIO.restoredWorkerState,
  })

  // SessionStart hooks can emit initialUserMessage — the first user turn for
  // headless orchestrator sessions where stdin is empty and additionalContext
  // alone (an attachment, not a turn) would leave the REPL with nothing to
  // respond to. The hook promise is awaited inside loadInitialMessages, so the
  // module-level pending value is set by the time we get here.
  const hookInitialUserMessage = takeInitialUserMessage()
  if (hookInitialUserMessage) {
    structuredIO.prependUserMessage(hookInitialUserMessage)
  }

  // Restore agent setting from the resumed session (if not overridden by current --agent flag
  // or settings-based agent, which would already have set mainThreadAgentType in main.tsx)
  if (!options.agent && !getMainThreadAgentType() && resumedAgentSetting) {
    const { agentDefinition: restoredAgent } = restoreAgentFromSession(
      resumedAgentSetting,
      undefined,
      { activeAgents: agents, allAgents: agents },
    )
    if (restoredAgent) {
      setAppState(prev => ({ ...prev, agent: restoredAgent.agentType }))
      // Apply the agent's system prompt for non-built-in agents (mirrors main.tsx initial --agent path)
      if (!options.systemPrompt && !isBuiltInAgent(restoredAgent)) {
        const agentSystemPrompt = restoredAgent.getSystemPrompt()
        if (agentSystemPrompt) {
          options.systemPrompt = agentSystemPrompt
        }
      }
      // Re-persist agent setting so future resumes maintain the agent
      saveAgentSetting(restoredAgent.agentType)
    }
  }

  // gracefulShutdownSync schedules an async shutdown and sets process.exitCode.
  // If a loadInitialMessages error path triggered it, bail early to avoid
  // unnecessary work while the process winds down.
  if (initialMessages.length === 0 && process.exitCode !== undefined) {
    return
  }

  // Handle --rewind-files: restore filesystem and exit immediately
  if (options.rewindFiles) {
    // File history snapshots are only created for user messages,
    // so we require the target to be a user message
    const targetMessage = initialMessages.find(
      m => m.uuid === options.rewindFiles,
    )

    if (!targetMessage || targetMessage.type !== 'user') {
      process.stderr.write(
        `Error: --rewind-files requires a user message UUID, but ${options.rewindFiles} is not a user message in this session\n`,
      )
      gracefulShutdownSync(1)
      return
    }

    const currentAppState = getAppState()
    const result = await handleRewindFiles(
      options.rewindFiles as UUID,
      currentAppState,
      setAppState,
      false,
    )
    if (!result.canRewind) {
      process.stderr.write(`Error: ${result.error || 'Unexpected error'}\n`)
      gracefulShutdownSync(1)
      return
    }

    // Rewind complete - exit successfully
    process.stdout.write(
      `Files rewound to state at message ${options.rewindFiles}\n`,
    )
    gracefulShutdownSync(0)
    return
  }

  // Check if we need input prompt - skip if we're resuming with a valid session ID/JSONL file or using SDK URL
  const hasValidResumeSessionId =
    typeof options.resume === 'string' &&
    (Boolean(validateUuid(options.resume)) || options.resume.endsWith('.jsonl'))
  const isUsingSdkUrl = Boolean(options.sdkUrl)

  if (!inputPrompt && !hasValidResumeSessionId && !isUsingSdkUrl) {
    process.stderr.write(
      `Error: Input must be provided either through stdin or as a prompt argument when using --print\n`,
    )
    gracefulShutdownSync(1)
    return
  }

  if (options.outputFormat === 'stream-json' && !options.verbose) {
    process.stderr.write(
      'Error: When using --print, --output-format=stream-json requires --verbose\n',
    )
    gracefulShutdownSync(1)
    return
  }

  // Filter out MCP tools that are in the deny list
  const allowedMcpTools = filterToolsByDenyRules(
    appState.mcp.tools,
    appState.toolPermissionContext,
  )
  let filteredTools = [...tools, ...allowedMcpTools]

  // When using SDK URL, always use stdio permission prompting to delegate to the SDK
  const effectivePermissionPromptToolName = options.sdkUrl
    ? 'stdio'
    : options.permissionPromptToolName

  // Callback for when a permission prompt is shown
  const onPermissionPrompt = (details: RequiresActionDetails) => {
    if (feature('COMMIT_ATTRIBUTION')) {
      setAppState(prev => ({
        ...prev,
        attribution: {
          ...prev.attribution,
          permissionPromptCount: prev.attribution.permissionPromptCount + 1,
        },
      }))
    }
    notifySessionStateChanged('requires_action', details)
  }

  const canUseTool = getCanUseToolFn(
    effectivePermissionPromptToolName,
    structuredIO,
    () => getAppState().mcp.tools,
    onPermissionPrompt,
  )
  if (options.permissionPromptToolName) {
    // Remove the permission prompt tool from the list of available tools.
    filteredTools = filteredTools.filter(
      tool => !toolMatchesName(tool, options.permissionPromptToolName!),
    )
  }

  // Install errors handlers to gracefully handle broken pipes (e.g., when parent process dies)
  registerProcessOutputErrorHandlers()

  headlessProfilerCheckpoint('after_loadInitialMessages')

  // Ensure model strings are initialized before generating model options.
  // For Bedrock users, this waits for the profile fetch to get correct region strings.
  await ensureModelStringsInitialized()
  headlessProfilerCheckpoint('after_modelStrings')

  // UDS inbox store registration is deferred until after `run` is defined
  // so we can pass `run` as the onEnqueue callback (see below).

  // Only `json` + `verbose` needs the full array (jsonStringify(messages) below).
  // For stream-json (SDK/CCR) and default text output, only the last message is
  // read for the exit code / final result. Avoid accumulating every message in
  // memory for the entire session.
  const needsFullArray = options.outputFormat === 'json' && options.verbose
  const messages: SDKMessage[] = []
  let lastMessage: SDKMessage | undefined
  // Streamlined mode transforms messages when CLAUDE_CODE_STREAMLINED_OUTPUT=true and using stream-json
  // Build flag gates this out of external builds; env var is the runtime opt-in for ant builds
  const transformToStreamlined =
    feature('STREAMLINED_OUTPUT') &&
    isEnvTruthy(process.env.CLAUDE_CODE_STREAMLINED_OUTPUT) &&
    options.outputFormat === 'stream-json'
      ? createStreamlinedTransformer()
      : null

  headlessProfilerCheckpoint('before_runHeadlessStreaming')
  for await (const message of runHeadlessStreaming(
    structuredIO,
    appState.mcp.clients,
    [...commands, ...appState.mcp.commands],
    filteredTools,
    initialMessages,
    canUseTool,
    sdkMcpConfigs,
    getAppState,
    setAppState,
    agents,
    options,
    turnInterruptionState,
  )) {
    if (transformToStreamlined) {
      // Streamlined mode: transform messages and stream immediately
      const transformed = transformToStreamlined(message)
      if (transformed) {
        await structuredIO.write(transformed)
      }
    } else if (options.outputFormat === 'stream-json' && options.verbose) {
      await structuredIO.write(message)
    }
    // Should not be getting control messages or stream events in non-stream mode.
    // Also filter out streamlined types since they're only produced by the transformer.
    // SDK-only system events are excluded so lastMessage stays at the result
    // (session_state_changed(idle) and any late task_notification drain after
    // result in the finally block).
    if (
      message.type !== 'control_response' &&
      message.type !== 'control_request' &&
      message.type !== 'control_cancel_request' &&
      !(
        message.type === 'system' &&
        (message.subtype === 'session_state_changed' ||
          message.subtype === 'task_notification' ||
          message.subtype === 'task_started' ||
          message.subtype === 'task_progress' ||
          message.subtype === 'post_turn_summary')
      ) &&
      message.type !== 'stream_event' &&
      message.type !== 'keep_alive' &&
      message.type !== 'streamlined_text' &&
      message.type !== 'streamlined_tool_use_summary' &&
      message.type !== 'prompt_suggestion'
    ) {
      if (needsFullArray) {
        messages.push(message)
      }
      lastMessage = message
    }
  }

  switch (options.outputFormat) {
    case 'json':
      if (!lastMessage || lastMessage.type !== 'result') {
        throw new Error('No messages returned')
      }
      if (options.verbose) {
        writeToStdout(jsonStringify(messages) + '\n')
        break
      }
      writeToStdout(jsonStringify(lastMessage) + '\n')
      break
    case 'stream-json':
      // already logged above
      break
    default:
      if (!lastMessage || lastMessage.type !== 'result') {
        throw new Error('No messages returned')
      }
      switch (lastMessage.subtype) {
        case 'success':
          writeToStdout(
            lastMessage.result.endsWith('\n')
              ? lastMessage.result
              : lastMessage.result + '\n',
          )
          break
        case 'error_during_execution':
          writeToStdout(`Execution error`)
          break
        case 'error_max_turns':
          writeToStdout(`Error: Reached max turns (${options.maxTurns})`)
          break
        case 'error_max_budget_usd':
          writeToStdout(`Error: Exceeded USD budget (${options.maxBudgetUsd})`)
          break
        case 'error_max_structured_output_retries':
          writeToStdout(
            `Error: Failed to provide valid structured output after maximum retries`,
          )
      }
  }

  // Log headless latency metrics for the final turn
  logHeadlessProfilerTurn()

  // Drain any in-flight memory extraction before shutdown. The response is
  // already flushed above, so this adds no user-visible latency — it just
  // delays process exit so gracefulShutdownSync's 5s failsafe doesn't kill
  // the forked agent mid-flight. Gated by isExtractModeActive so the
  // tengu_slate_thimble flag controls non-interactive extraction end-to-end.
  if (feature('EXTRACT_MEMORIES') && isExtractModeActive()) {
    await extractMemoriesModule!.drainPendingExtraction()
  }

  gracefulShutdownSync(
    lastMessage?.type === 'result' && lastMessage?.is_error ? 1 : 0,
  )
}

function runHeadlessStreaming(
  structuredIO: StructuredIO,
  mcpClients: MCPServerConnection[],
  commands: Command[],
  tools: Tools,
  initialMessages: Message[],
  canUseTool: CanUseToolFn,
  sdkMcpConfigs: Record<string, McpSdkServerConfig>,
  getAppState: () => AppState,
  setAppState: (f: (prev: AppState) => AppState) => void,
  agents: AgentDefinition[],
  options: {
    verbose: boolean | undefined
    jsonSchema: Record<string, unknown> | undefined
    permissionPromptToolName: string | undefined
    allowedTools: string[] | undefined
    thinkingConfig: ThinkingConfig | undefined
    maxTurns: number | undefined
    maxBudgetUsd: number | undefined
    taskBudget: { total: number } | undefined
    systemPrompt: string | undefined
    appendSystemPrompt: string | undefined
    userSpecifiedModel: string | undefined
    fallbackModel: string | undefined
    replayUserMessages?: boolean | undefined
    includePartialMessages?: boolean | undefined
    enableAuthStatus?: boolean | undefined
    agent?: string | undefined
    setSDKStatus?: (status: SDKStatus) => void
    promptSuggestions?: boolean | undefined
    workload?: string | undefined
  },
  turnInterruptionState?: TurnInterruptionState,
): AsyncIterable<StdoutMessage> {
  let running = false
  let runPhase:
    | 'draining_commands'
    | 'waiting_for_agents'
    | 'finally_flush'
    | 'finally_post_flush'
    | undefined
  let inputClosed = false
  let shutdownPromptInjected = false
  let heldBackResult: StdoutMessage | null = null
  let abortController: AbortController | undefined
  // Same queue sendRequest() enqueues to — one FIFO for everything.
  const output = structuredIO.outbound

  // Ctrl+C in -p mode: abort the in-flight query, then shut down gracefully.
  // gracefulShutdown persists session state and flushes analytics, with a
  // failsafe timer that force-exits if cleanup hangs.
  const sigintHandler = () => {
    logForDiagnosticsNoPII('info', 'shutdown_signal', { signal: 'SIGINT' })
    if (abortController && !abortController.signal.aborted) {
      abortController.abort()
    }
    void gracefulShutdown(0)
  }
  process.on('SIGINT', sigintHandler)

  // Dump run()'s state at SIGTERM so a stuck session's healthsweep can name
  // the do/while(waitingForAgents) poll without reading the transcript.
  registerCleanup(async () => {
    const bg: Record<string, number> = {}
    for (const t of getRunningTasks(getAppState())) {
      if (isBackgroundTask(t)) bg[t.type] = (bg[t.type] ?? 0) + 1
    }
    logForDiagnosticsNoPII('info', 'run_state_at_shutdown', {
      run_active: running,
      run_phase: runPhase,
      worker_status: getSessionState(),
      internal_events_pending: structuredIO.internalEventsPending,
      bg_tasks: bg,
    })
  })

  // Wire the central onChangeAppState mode-diff hook to the SDK output stream.
  // This fires whenever ANY code path mutates toolPermissionContext.mode —
  // Shift+Tab, ExitPlanMode dialog, /plan slash command, rewind, bridge
  // set_permission_mode, the query loop, stop_task — rather than the two
  // paths that previously went through a bespoke wrapper.
  // The wrapper's body was fully redundant (it enqueued here AND called
  // notifySessionMetadataChanged, both of which onChangeAppState now covers);
  // keeping it would double-emit status messages.
  setPermissionModeChangedListener(newMode => {
    // Only emit for SDK-exposed modes.
    if (
      newMode === 'default' ||
      newMode === 'acceptEdits' ||
      newMode === 'bypassPermissions' ||
      newMode === 'plan' ||
      newMode === (feature('TRANSCRIPT_CLASSIFIER') && 'auto') ||
      newMode === 'dontAsk'
    ) {
      output.enqueue({
        type: 'system',
        subtype: 'status',
        status: null,
        permissionMode: newMode as PermissionMode,
        uuid: randomUUID(),
        session_id: getSessionId(),
      })
    }
  })

  // Prompt suggestion tracking (push model)
  const suggestionState: {
    abortController: AbortController | null
    inflightPromise: Promise<void> | null
    lastEmitted: {
      text: string
      emittedAt: number
      promptId: PromptVariant
      generationRequestId: string | null
    } | null
    pendingSuggestion: {
      type: 'prompt_suggestion'
      suggestion: string
      uuid: UUID
      session_id: string
    } | null
    pendingLastEmittedEntry: {
      text: string
      promptId: PromptVariant
      generationRequestId: string | null
    } | null
  } = {
    abortController: null,
    inflightPromise: null,
    lastEmitted: null,
    pendingSuggestion: null,
    pendingLastEmittedEntry: null,
  }

  // Set up AWS auth status listener if enabled
  let unsubscribeAuthStatus: (() => void) | undefined
  if (options.enableAuthStatus) {
    const authStatusManager = AwsAuthStatusManager.getInstance()
    unsubscribeAuthStatus = authStatusManager.subscribe(status => {
      output.enqueue({
        type: 'auth_status',
        isAuthenticating: status.isAuthenticating,
        output: status.output,
        error: status.error,
        uuid: randomUUID(),
        session_id: getSessionId(),
      })
    })
  }

  // Set up rate limit status listener to emit SDKRateLimitEvent for all status changes.
  // Emitting for all statuses (including 'allowed') ensures consumers can clear warnings
  // when rate limits reset. The upstream emitStatusChange already deduplicates via isEqual.
  const rateLimitListener = (limits: ClaudeAILimits) => {
    const rateLimitInfo = toSDKRateLimitInfo(limits)
    if (rateLimitInfo) {
      output.enqueue({
        type: 'rate_limit_event',
        rate_limit_info: rateLimitInfo,
        uuid: randomUUID(),
        session_id: getSessionId(),
      })
    }
  }
  statusListeners.add(rateLimitListener)

  // Messages for internal tracking, directly mutated by ask(). These messages
  // include Assistant, User, Attachment, and Progress messages.
  // TODO: Clean up this code to avoid passing around a mutable array.
  const mutableMessages: Message[] = initialMessages

  // Seed the readFileState cache from the transcript (content the model saw,
  // with message timestamps) so getChangedFiles can detect external edits.
  // This cache instance must persist across ask() calls, since the edit tool
  // relies on this as a global state.
  let readFileState = extractReadFilesFromMessages(
    initialMessages,
    cwd(),
    READ_FILE_STATE_CACHE_SIZE,
  )

  // Client-supplied readFileState seeds (via seed_read_state control request).
  // The stdin IIFE runs concurrently with ask() — a seed arriving mid-turn
  // would be lost to ask()'s clone-then-replace (QueryEngine.ts finally block)
  // if written directly into readFileState. Instead, seeds land here, merge
  // into getReadFileCache's view (readFileState-wins-ties: seeds fill gaps),
  // and are re-applied then CLEARED in setReadFileCache. One-shot: each seed
  // survives exactly one clone-replace cycle, then becomes a regular
  // readFileState entry subject to compact's clear like everything else.
  const pendingSeeds = createFileStateCacheWithSizeLimit(
    READ_FILE_STATE_CACHE_SIZE,
  )

  // Auto-resume interrupted turns on restart so CC continues from where it
  // left off without requiring the SDK to re-send the prompt.
  const resumeInterruptedTurnEnv =
    process.env.CLAUDE_CODE_RESUME_INTERRUPTED_TURN
  if (
    turnInterruptionState &&
    turnInterruptionState.kind !== 'none' &&
    resumeInterruptedTurnEnv
  ) {
    logForDebugging(
      `[print.ts] Auto-resuming interrupted turn (kind: ${turnInterruptionState.kind})`,
    )

    // Remove the interrupted message and its sentinel, then re-enqueue so
    // the model sees it exactly once. For mid-turn interruptions, the
    // deserialization layer transforms them into interrupted_prompt by
    // appending a synthetic "Continue from where you left off." message.
    removeInterruptedMessage(mutableMessages, turnInterruptionState.message)
    enqueue({
      mode: 'prompt',
      value: turnInterruptionState.message.message.content,
      uuid: randomUUID(),
    })
  }

  const modelOptions = getModelOptions()
  const modelInfos = modelOptions.map(option => {
    const modelId = option.value === null ? 'default' : option.value
    const resolvedModel =
      modelId === 'default'
        ? getDefaultMainLoopModel()
        : parseUserSpecifiedModel(modelId)
    const hasEffort = modelSupportsEffort(resolvedModel)
    const hasAdaptiveThinking = modelSupportsAdaptiveThinking(resolvedModel)
    const hasFastMode = isFastModeSupportedByModel(option.value)
    const hasAutoMode = modelSupportsAutoMode(resolvedModel)
    return {
      value: modelId,
      displayName: option.label,
      description: option.description,
      ...(hasEffort && {
        supportsEffort: true,
        supportedEffortLevels: modelSupportsMaxEffort(resolvedModel)
          ? [...EFFORT_LEVELS]
          : EFFORT_LEVELS.filter(l => l !== 'max'),
      }),
      ...(hasAdaptiveThinking && { supportsAdaptiveThinking: true }),
      ...(hasFastMode && { supportsFastMode: true }),
      ...(hasAutoMode && { supportsAutoMode: true }),
    }
  })
  let activeUserSpecifiedModel = options.userSpecifiedModel

  function injectModelSwitchBreadcrumbs(
    modelArg: string,
    resolvedModel: string,
  ): void {
    const breadcrumbs = createModelSwitchBreadcrumbs(
      modelArg,
      modelDisplayString(resolvedModel),
    )
    mutableMessages.push(...breadcrumbs)
    for (const crumb of breadcrumbs) {
      if (
        typeof crumb.message.content === 'string' &&
        crumb.message.content.includes(`<${LOCAL_COMMAND_STDOUT_TAG}>`)
      ) {
        output.enqueue({
          type: 'user',
          message: crumb.message,
          session_id: getSessionId(),
          parent_tool_use_id: null,
          uuid: crumb.uuid,
          timestamp: crumb.timestamp,
          isReplay: true,
        } satisfies SDKUserMessageReplay)
      }
    }
  }

  // Cache SDK MCP clients to avoid reconnecting on each run
  let sdkClients: MCPServerConnection[] = []
  let sdkTools: Tools = []

  // Track which MCP clients have had elicitation handlers registered
  const elicitationRegistered = new Set<string>()

  /**
   * Register elicitation request/completion handlers on connected MCP clients
   * that haven't been registered yet. SDK MCP servers are excluded because they
   * route through SdkControlClientTransport. Hooks run first (matching REPL
   * behavior); if no hook responds, the request is forwarded to the SDK
   * consumer via the control protocol.
   */
  function registerElicitationHandlers(clients: MCPServerConnection[]): void {
    for (const connection of clients) {
      if (
        connection.type !== 'connected' ||
        elicitationRegistered.has(connection.name)
      ) {
        continue
      }
      // Skip SDK MCP servers — elicitation flows through SdkControlClientTransport
      if (connection.config.type === 'sdk') {
        continue
      }
      const serverName = connection.name

      // Wrapped in try/catch because setRequestHandler throws if the client wasn't
      // created with elicitation capability declared (e.g., SDK-created clients).
      try {
        connection.client.setRequestHandler(
          ElicitRequestSchema,
          async (request, extra) => {
            logMCPDebug(
              serverName,
              `Elicitation request received in print mode: ${jsonStringify(request)}`,
            )

            const mode = request.params.mode === 'url' ? 'url' : 'form'

            logEvent('tengu_mcp_elicitation_shown', {
              mode: mode as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
            })

            // Run elicitation hooks first — they can provide a response programmatically
            const hookResponse = await runElicitationHooks(
              serverName,
              request.params,
              extra.signal,
            )
            if (hookResponse) {
              logMCPDebug(
                serverName,
                `Elicitation resolved by hook: ${jsonStringify(hookResponse)}`,
              )
              logEvent('tengu_mcp_elicitation_response', {
                mode: mode as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
                action:
                  hookResponse.action as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
              })
              return hookResponse
            }

            // Delegate to SDK consumer via control protocol
            const url =
              'url' in request.params
                ? (request.params.url as string)
                : undefined
            const requestedSchema =
              'requestedSchema' in request.params
                ? (request.params.requestedSchema as
                    | Record<string, unknown>
                    | undefined)
                : undefined

            const elicitationId =
              'elicitationId' in request.params
                ? (request.params.elicitationId as string | undefined)
                : undefined

            const rawResult = await structuredIO.handleElicitation(
              serverName,
              request.params.message,
              requestedSchema,
              extra.signal,
              mode,
              url,
              elicitationId,
            )

            const result = await runElicitationResultHooks(
              serverName,
              rawResult,
              extra.signal,
              mode,
              elicitationId,
            )

            logEvent('tengu_mcp_elicitation_response', {
              mode: mode as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
              action:
                result.action as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
            })
            return result
          },
        )

        // Surface completion notifications to SDK consumers (URL mode)
        connection.client.setNotificationHandler(
          ElicitationCompleteNotificationSchema,
          notification => {
            const { elicitationId } = notification.params
            logMCPDebug(
              serverName,
              `Elicitation completion notification: ${elicitationId}`,
            )
            void executeNotificationHooks({
              message: `MCP server "${serverName}" confirmed elicitation ${elicitationId} complete`,
              notificationType: 'elicitation_complete',
            })
            output.enqueue({
              type: 'system',
              subtype: 'elicitation_complete',
              mcp_server_name: serverName,
              elicitation_id: elicitationId,
              uuid: randomUUID(),
              session_id: getSessionId(),
            })
          },
        )

        elicitationRegistered.add(serverName)
      } catch {
        // setRequestHandler throws if the client wasn't created with
        // elicitation capability — skip silently
      }
    }
  }

  async function updateSdkMcp() {
    // Check if SDK MCP servers need to be updated (new servers added or removed)
    const currentServerNames = new Set(Object.keys(sdkMcpConfigs))
    const connectedServerNames = new Set(sdkClients.map(c => c.name))

    // Check if there are any differences (additions or removals)
    const hasNewServers = Array.from(currentServerNames).some(
      name => !connectedServerNames.has(name),
    )
    const hasRemovedServers = Array.from(connectedServerNames).some(
      name => !currentServerNames.has(name),
    )
    // Check if any SDK clients are pending and need to be upgraded
    const hasPendingSdkClients = sdkClients.some(c => c.type === 'pending')
    // Check if any SDK clients failed their handshake and need to be retried.
    // Without this, a client that lands in 'failed' (e.g. handshake timeout on
    // a WS reconnect race) stays failed forever — its name satisfies the
    // connectedServerNames diff but it contributes zero tools.
    const hasFailedSdkClients = sdkClients.some(c => c.type === 'failed')

    const haveServersChanged =
      hasNewServers ||
      hasRemovedServers ||
      hasPendingSdkClients ||
      hasFailedSdkClients

    if (haveServersChanged) {
      // Clean up removed servers
      for (const client of sdkClients) {
        if (!currentServerNames.has(client.name)) {
          if (client.type === 'connected') {
            await client.cleanup()
          }
        }
      }

      // Re-initialize all SDK MCP servers with current config
      const sdkSetup = await setupSdkMcpClients(
        sdkMcpConfigs,
        (serverName, message) =>
          structuredIO.sendMcpMessage(serverName, message),
      )
      sdkClients = sdkSetup.clients
      sdkTools = sdkSetup.tools

      // Store SDK MCP tools in appState so subagents can access them via
      // assembleToolPool. Only tools are stored here — SDK clients are already
      // merged separately in the query loop (allMcpClients) and mcp_status handler.
      // Use both old (connectedServerNames) and new (currentServerNames) to remove
      // stale SDK tools when servers are added or removed.
      const allSdkNames = uniq([...connectedServerNames, ...currentServerNames])
      setAppState(prev => ({
        ...prev,
        mcp: {
          ...prev.mcp,
          tools: [
            ...prev.mcp.tools.filter(
              t =>
                !allSdkNames.some(name =>
                  t.name.startsWith(getMcpPrefix(name)),
                ),
            ),
            ...sdkTools,
          ],
        },
      }))

      // Set up the special internal VSCode MCP server if necessary.
      setupVscodeSdkMcp(sdkClients)
    }
  }

  void updateSdkMcp()

  // State for dynamically added MCP servers (via mcp_set_servers control message)
  // These are separate from SDK MCP servers and support all transport types
  let dynamicMcpState: DynamicMcpState = {
    clients: [],
    tools: [],
    configs: {},
  }

  // Shared tool assembly for ask() and the get_context_usage control request.
  // Closes over the mutable sdkTools/dynamicMcpState bindings so both call
  // sites see late-connecting servers.
  const buildAllTools = (appState: AppState): Tools => {
    const assembledTools = assembleToolPool(
      appState.toolPermissionContext,
      appState.mcp.tools,
    )
    let allTools = uniqBy(
      mergeAndFilterTools(
        [...tools, ...sdkTools, ...dynamicMcpState.tools],
        assembledTools,
        appState.toolPermissionContext.mode,
      ),
      'name',
    )
    if (options.permissionPromptToolName) {
      allTools = allTools.filter(
        tool => !toolMatchesName(tool, options.permissionPromptToolName!),
      )
    }
    const initJsonSchema = getInitJsonSchema()
    if (initJsonSchema && !options.jsonSchema) {
      const syntheticOutputResult = createSyntheticOutputTool(initJsonSchema)
      if ('tool' in syntheticOutputResult) {
        allTools = [...allTools, syntheticOutputResult.tool]
      }
    }
    return allTools
  }

  // Bridge handle for remote-control (SDK control message).
  // Mirrors the REPL's useReplBridge hook: the handle is created when
  // `remote_control` is enabled and torn down when disabled.
  let bridgeHandle: ReplBridgeHandle | null = null
  // Cursor into mutableMessages — tracks how far we've forwarded.
  // Same index-based diff as useReplBridge's lastWrittenIndexRef.
  let bridgeLastForwardedIndex = 0

  // Forward new messages from mutableMessages to the bridge.
  // Called incrementally during each turn (so claude.ai sees progress
  // and stays alive during permission waits) and again after the turn.
  //
  // writeMessages has its own UUID-based dedup (initialMessageUUIDs,
  // recentPostedUUIDs) — the index cursor here is a pre-filter to avoid
  // O(n) re-scanning of already-sent messages on every call.
  function forwardMessagesToBridge(): void {
    if (!bridgeHandle) return
    // Guard against mutableMessages shrinking (compaction truncates it).
    const startIndex = Math.min(
      bridgeLastForwardedIndex,
      mutableMessages.length,
    )
    const newMessages = mutableMessages
      .slice(startIndex)
      .filter(m => m.type === 'user' || m.type === 'assistant')
    bridgeLastForwardedIndex = mutableMessages.length
    if (newMessages.length > 0) {
      bridgeHandle.writeMessages(newMessages)
    }
  }

  // Helper to apply MCP server changes - used by both mcp_set_servers control message
  // and background plugin installation.
  // NOTE: Nested function required - mutates closure state (sdkMcpConfigs, sdkClients, etc.)
  let mcpChangesPromise: Promise<{
    response: SDKControlMcpSetServersResponse
    sdkServersChanged: boolean
  }> = Promise.resolve({
    response: {
      added: [] as string[],
      removed: [] as string[],
      errors: {} as Record<string, string>,
    },
    sdkServersChanged: false,
  })

  function applyMcpServerChanges(
    servers: Record<string, McpServerConfigForProcessTransport>,
  ): Promise<{
    response: SDKControlMcpSetServersResponse
    sdkServersChanged: boolean
  }> {
    // Serialize calls to prevent race conditions between concurrent callers
    // (background plugin install and mcp_set_servers control messages)
    const doWork = async (): Promise<{
      response: SDKControlMcpSetServersResponse
      sdkServersChanged: boolean
    }> => {
      const oldSdkClientNames = new Set(sdkClients.map(c => c.name))

      const result = await handleMcpSetServers(
        servers,
        { configs: sdkMcpConfigs, clients: sdkClients, tools: sdkTools },
        dynamicMcpState,
        setAppState,
      )

      // Update SDK state (need to mutate sdkMcpConfigs since it's shared)
      for (const key of Object.keys(sdkMcpConfigs)) {
        delete sdkMcpConfigs[key]
      }
      Object.assign(sdkMcpConfigs, result.newSdkState.configs)
      sdkClients = result.newSdkState.clients
      sdkTools = result.newSdkState.tools
      dynamicMcpState = result.newDynamicState

      // Keep appState.mcp.tools in sync so subagents can see SDK MCP tools.
      // Use both old and new SDK client names to remove stale tools.
      if (result.sdkServersChanged) {
        const newSdkClientNames = new Set(sdkClients.map(c => c.name))
        const allSdkNames = uniq([...oldSdkClientNames, ...newSdkClientNames])
        setAppState(prev => ({
          ...prev,
          mcp: {
            ...prev.mcp,
            tools: [
              ...prev.mcp.tools.filter(
                t =>
                  !allSdkNames.some(name =>
                    t.name.startsWith(getMcpPrefix(name)),
                  ),
              ),
              ...sdkTools,
            ],
          },
        }))
      }

      return {
        response: result.response,
        sdkServersChanged: result.sdkServersChanged,
      }
    }

    mcpChangesPromise = mcpChangesPromise.then(doWork, doWork)
    return mcpChangesPromise
  }

  // Build McpServerStatus[] for control responses. Shared by mcp_status and
  // reload_plugins handlers. Reads closure state: sdkClients, dynamicMcpState.
  function buildMcpServerStatuses(): McpServerStatus[] {
    const currentAppState = getAppState()
    const currentMcpClients = currentAppState.mcp.clients
    const allMcpTools = uniqBy(
      [...currentAppState.mcp.tools, ...dynamicMcpState.tools],
      'name',
    )
    const existingNames = new Set([
      ...currentMcpClients.map(c => c.name),
      ...sdkClients.map(c => c.name),
    ])
    return [
      ...currentMcpClients,
      ...sdkClients,
      ...dynamicMcpState.clients.filter(c => !existingNames.has(c.name)),
    ].map(connection => {
      let config
      if (
        connection.config.type === 'sse' ||
        connection.config.type === 'http'
      ) {
        config = {
          type: connection.config.type,
          url: connection.config.url,
          headers: connection.config.headers,
          oauth: connection.config.oauth,
        }
      } else if (connection.config.type === 'claudeai-proxy') {
        config = {
          type: 'claudeai-proxy' as const,
          url: connection.config.url,
          id: connection.config.id,
        }
      } else if (
        connection.config.type === 'stdio' ||
        connection.config.type === undefined
      ) {
        config = {
          type: 'stdio' as const,
          command: connection.config.command,
          args: connection.config.args,
        }
      }
      const serverTools =
        connection.type === 'connected'
          ? filterToolsByServer(allMcpTools, connection.name).map(tool => ({
              name: tool.mcpInfo?.toolName ?? tool.name,
              annotations: {
                readOnly: tool.isReadOnly({}) || undefined,
                destructive: tool.isDestructive?.({}) || undefined,
                openWorld: tool.isOpenWorld?.({}) || undefined,
              },
            }))
          : undefined
      // Capabilities passthrough with allowlist pre-filter. The IDE reads
      // experimental['claude/channel'] to decide whether to show the
      // Enable-channel prompt — only echo it if channel_enable would
      // actually pass the allowlist. Not a security boundary (the
      // handler re-runs the full gate); just avoids dead buttons.
      let capabilities: { experimental?: Record<string, unknown> } | undefined
      if (
        (feature('KAIROS') || feature('KAIROS_CHANNELS')) &&
        connection.type === 'connected' &&
        connection.capabilities.experimental
      ) {
        const exp = { ...connection.capabilities.experimental }
        if (
          exp['claude/channel'] &&
          (!isChannelsEnabled() ||
            !isChannelAllowlisted(connection.config.pluginSource))
        ) {
          delete exp['claude/channel']
        }
        if (Object.keys(exp).length > 0) {
          capabilities = { experimental: exp }
        }
      }
      return {
        name: connection.name,
        status: connection.type,
        serverInfo:
          connection.type === 'connected' ? connection.serverInfo : undefined,
        error: connection.type === 'failed' ? connection.error : undefined,
        config,
        scope: connection.config.scope,
        tools: serverTools,
        capabilities,
      }
    })
  }

  // NOTE: Nested function required - needs closure access to applyMcpServerChanges and updateSdkMcp
  async function installPluginsAndApplyMcpInBackground(): Promise<void> {
    try {
      // Join point for user settings (fired at runHeadless entry) and managed
      // settings (fired in main.tsx preAction). downloadUserSettings() caches
      // its promise so this awaits the same in-flight request.
      await Promise.all([
        feature('DOWNLOAD_USER_SETTINGS') &&
        (isEnvTruthy(process.env.CLAUDE_CODE_REMOTE) || getIsRemoteMode())
          ? withDiagnosticsTiming('headless_user_settings_download', () =>
              downloadUserSettings(),
            )
          : Promise.resolve(),
        withDiagnosticsTiming('headless_managed_settings_wait', () =>
          waitForRemoteManagedSettingsToLoad(),
        ),
      ])

      const pluginsInstalled = await installPluginsForHeadless()

      if (pluginsInstalled) {
        await applyPluginMcpDiff()
      }
    } catch (error) {
      logError(error)
    }
  }

  // Background plugin installation for all headless users
  // Installs marketplaces from extraKnownMarketplaces and missing enabled plugins
  // CLAUDE_CODE_SYNC_PLUGIN_INSTALL=true: resolved in run() before the first
  // query so plugins are guaranteed available on the first ask().
  let pluginInstallPromise: Promise<void> | null = null
  // --bare / SIMPLE: skip plugin install. Scripted calls don't add plugins
  // mid-session; the next interactive run reconciles.
  if (!isBareMode()) {
    if (isEnvTruthy(process.env.CLAUDE_CODE_SYNC_PLUGIN_INSTALL)) {
      pluginInstallPromise = installPluginsAndApplyMcpInBackground()
    } else {
      void installPluginsAndApplyMcpInBackground()
    }
  }

  // Idle timeout management
  const idleTimeout = createIdleTimeoutManager(() => !running)

  // Mutable commands and agents for hot reloading
  let currentCommands = commands
  let currentAgents = agents

  // Clear all plugin-related caches, reload commands/agents/hooks.
  // Called after CLAUDE_CODE_SYNC_PLUGIN_INSTALL completes (before first query)
  // and after non-sync background install finishes.
  // refreshActivePlugins calls clearAllCaches() which is required because
  // loadAllPlugins() may have run during main.tsx startup BEFORE managed
  // settings were fetched. Without clearing, getCommands() would rebuild
  // from a stale plugin list.
  async function refreshPluginState(): Promise<void> {
    // refreshActivePlugins handles the full cache sweep (clearAllCaches),
    // reloads all plugin component loaders, writes AppState.plugins +
    // AppState.agentDefinitions, registers hooks, and bumps mcp.pluginReconnectKey.
    const { agentDefinitions: freshAgentDefs } =
      await refreshActivePlugins(setAppState)

    // Headless-specific: currentCommands/currentAgents are local mutable refs
    // captured by the query loop (REPL uses AppState instead). getCommands is
    // fresh because refreshActivePlugins cleared its cache.
    currentCommands = await getCommands(cwd())

    // Preserve SDK-provided agents (--agents CLI flag or SDK initialize
    // control_request) — both inject via parseAgentsFromJson with
    // source='flagSettings'. loadMarkdownFilesForSubdir never assigns this
    // source, so it cleanly discriminates "injected, not disk-loadable".
    //
    // The previous filter used a negative set-diff (!freshAgentTypes.has(a))
    // which also matched plugin agents that were in the poisoned initial
    // currentAgents but correctly excluded from freshAgentDefs after managed
    // settings applied — leaking policy-blocked agents into the init message.
    // See gh-23085: isBridgeEnabled() at Commander-definition time poisoned
    // the settings cache before setEligibility(true) ran.
    const sdkAgents = currentAgents.filter(a => a.source === 'flagSettings')
    currentAgents = [...freshAgentDefs.allAgents, ...sdkAgents]
  }

  // Re-diff MCP configs after plugin state changes. Filters to
  // process-transport-supported types and carries SDK-mode servers through
  // so applyMcpServerChanges' diff doesn't close their transports.
  // Nested: needs closure access to sdkMcpConfigs, applyMcpServerChanges,
  // updateSdkMcp.
  async function applyPluginMcpDiff(): Promise<void> {
    const { servers: newConfigs } = await getAllMcpConfigs()
    const supportedConfigs: Record<string, McpServerConfigForProcessTransport> =
      {}
    for (const [name, config] of Object.entries(newConfigs)) {
      const type = config.type
      if (
        type === undefined ||
        type === 'stdio' ||
        type === 'sse' ||
        type === 'http' ||
        type === 'sdk'
      ) {
        supportedConfigs[name] = config
      }
    }
    for (const [name, config] of Object.entries(sdkMcpConfigs)) {
      if (config.type === 'sdk' && !(name in supportedConfigs)) {
        supportedConfigs[name] = config
      }
    }
    const { response, sdkServersChanged } =
      await applyMcpServerChanges(supportedConfigs)
    if (sdkServersChanged) {
      void updateSdkMcp()
    }
    logForDebugging(
      `Headless MCP refresh: added=${response.added.length}, removed=${response.removed.length}`,
    )
  }

  // Subscribe to skill changes for hot reloading
  const unsubscribeSkillChanges = skillChangeDetector.subscribe(() => {
    clearCommandsCache()
    void getCommands(cwd()).then(newCommands => {
      currentCommands = newCommands
    })
  })

  // Proactive mode: schedule a tick to keep the model looping autonomously.
  // setTimeout(0) yields to the event loop so pending stdin messages
  // (interrupts, user messages) are processed before the tick fires.
  const scheduleProactiveTick =
    feature('PROACTIVE') || feature('KAIROS')
      ? () => {
          setTimeout(() => {
            if (
              !proactiveModule?.isProactiveActive() ||
              proactiveModule.isProactivePaused() ||
              inputClosed
            ) {
              return
            }
            const tickContent = `<${TICK_TAG}>${new Date().toLocaleTimeString()}</${TICK_TAG}>`
            enqueue({
              mode: 'prompt' as const,
              value: tickContent,
              uuid: randomUUID(),
              priority: 'later',
              isMeta: true,
            })
            void run()
          }, 0)
        }
      : undefined

  // Abort the current operation when a 'now' priority message arrives.
  subscribeToCommandQueue(() => {
    if (abortController && getCommandsByMaxPriority('now').length > 0) {
      abortController.abort('interrupt')
    }
  })

  const run = async () => {
    if (running) {
      return
    }

    running = true
    runPhase = undefined
    notifySessionStateChanged('running')
    idleTimeout.stop()

    headlessProfilerCheckpoint('run_entry')
    // TODO(custom-tool-refactor): Should move to the init message, like browser

    await updateSdkMcp()
    headlessProfilerCheckpoint('after_updateSdkMcp')

    // Resolve deferred plugin installation (CLAUDE_CODE_SYNC_PLUGIN_INSTALL).
    // The promise was started eagerly so installation overlaps with other init.
    // Awaiting here guarantees plugins are available before the first ask().
    // If CLAUDE_CODE_SYNC_PLUGIN_INSTALL_TIMEOUT_MS is set, races against that
    // deadline and proceeds without plugins on timeout (logging an error).
    if (pluginInstallPromise) {
      const timeoutMs = parseInt(
        process.env.CLAUDE_CODE_SYNC_PLUGIN_INSTALL_TIMEOUT_MS || '',
        10,
      )
      if (timeoutMs > 0) {
        const timeout = sleep(timeoutMs).then(() => 'timeout' as const)
        const result = await Promise.race([pluginInstallPromise, timeout])
        if (result === 'timeout') {
          logError(
            new Error(
              `CLAUDE_CODE_SYNC_PLUGIN_INSTALL: plugin installation timed out after ${timeoutMs}ms`,
            ),
          )
          logEvent('tengu_sync_plugin_install_timeout', {
            timeout_ms: timeoutMs,
          })
        }
      } else {
        await pluginInstallPromise
      }
      pluginInstallPromise = null

      // Refresh commands, agents, and hooks now that plugins are installed
      await refreshPluginState()

      // Set up hot-reload for plugin hooks now that the initial install is done.
      // In sync-install mode, setup.ts skips this to avoid racing with the install.
      const { setupPluginHookHotReload } = await import(
        '../utils/plugins/loadPluginHooks.js'
      )
      setupPluginHookHotReload()
    }

    // Only main-thread commands (agentId===undefined) — subagent
    // notifications are drained by the subagent's mid-turn gate in query.ts.
    // Defined outside the try block so it's accessible in the post-finally
    // queue re-checks at the bottom of run().
    const isMainThread = (cmd: QueuedCommand) => cmd.agentId === undefined

    try {
      let command: QueuedCommand | undefined
      let waitingForAgents = false

      // Extract command processing into a named function for the do-while pattern.
      // Drains the queue, batching consecutive prompt-mode commands into one
      // ask() call so messages that queued up during a long turn coalesce
      // into a single follow-up turn instead of N separate turns.
      const drainCommandQueue = async () => {
        while ((command = dequeue(isMainThread))) {
          if (
            command.mode !== 'prompt' &&
            command.mode !== 'orphaned-permission' &&
            command.mode !== 'task-notification'
          ) {
            throw new Error(
              'only prompt commands are supported in streaming mode',
            )
          }

          // Non-prompt commands (task-notification, orphaned-permission) carry
          // side effects or orphanedPermission state, so they process singly.
          // Prompt commands greedily collect followers with matching workload.
          const batch: QueuedCommand[] = [command]
          if (command.mode === 'prompt') {
            while (canBatchWith(command, peek(isMainThread))) {
              batch.push(dequeue(isMainThread)!)
            }
            if (batch.length > 1) {
              command = {
                ...command,
                value: joinPromptValues(batch.map(c => c.value)),
                uuid: batch.findLast(c => c.uuid)?.uuid ?? command.uuid,
              }
            }
          }
          const batchUuids = batch.map(c => c.uuid).filter(u => u !== undefined)

          // QueryEngine will emit a replay for command.uuid (the last uuid in
          // the batch) via its messagesToAck path. Emit replays here for the
          // rest so consumers that track per-uuid delivery (clank's
          // asyncMessages footer, CCR) see an ack for every message they sent,
          // not just the one that survived the merge.
          if (options.replayUserMessages && batch.length > 1) {
            for (const c of batch) {
              if (c.uuid && c.uuid !== command.uuid) {
                output.enqueue({
                  type: 'user',
                  message: { role: 'user', content: c.value },
                  session_id: getSessionId(),
                  parent_tool_use_id: null,
                  uuid: c.uuid,
                  isReplay: true,
                } satisfies SDKUserMessageReplay)
              }
            }
          }

          // Combine all MCP clients. appState.mcp is populated incrementally
          // per-server by main.tsx (mirrors useManageMCPConnections). Reading
          // fresh per-command means late-connecting servers are visible on the
          // next turn. registerElicitationHandlers is idempotent (tracking set).
          const appState = getAppState()
          const allMcpClients = [
            ...appState.mcp.clients,
            ...sdkClients,
            ...dynamicMcpState.clients,
          ]
          registerElicitationHandlers(allMcpClients)
          // Channel handlers for servers allowlisted via --channels at
          // construction time (or enableChannel() mid-session). Runs every
          // turn like registerElicitationHandlers — idempotent per-client
          // (setNotificationHandler replaces, not stacks) and no-ops for
          // non-allowlisted servers (one feature-flag check).
          for (const client of allMcpClients) {
            reregisterChannelHandlerAfterReconnect(client)
          }

          const allTools = buildAllTools(appState)

          for (const uuid of batchUuids) {
            notifyCommandLifecycle(uuid, 'started')
          }

          // Task notifications arrive when background agents complete.
          // Emit an SDK system event for SDK consumers, then fall through
          // to ask() so the model sees the agent result and can act on it.
          // This matches TUI behavior where useQueueProcessor always feeds
          // notifications to the model regardless of coordinator mode.
          if (command.mode === 'task-notification') {
            const notificationText =
              typeof command.value === 'string' ? command.value : ''
            // Parse the XML-formatted notification
            const taskIdMatch = notificationText.match(
              /<task-id>([^<]+)<\/task-id>/,
            )
            const toolUseIdMatch = notificationText.match(
              /<tool-use-id>([^<]+)<\/tool-use-id>/,
            )
            const outputFileMatch = notificationText.match(
              /<output-file>([^<]+)<\/output-file>/,
            )
            const statusMatch = notificationText.match(
              /<status>([^<]+)<\/status>/,
            )
            const summaryMatch = notificationText.match(
              /<summary>([^<]+)<\/summary>/,
            )

            const isValidStatus = (
              s: string | undefined,
            ): s is 'completed' | 'failed' | 'stopped' | 'killed' =>
              s === 'completed' ||
              s === 'failed' ||
              s === 'stopped' ||
              s === 'killed'
            const rawStatus = statusMatch?.[1]
            const status = isValidStatus(rawStatus)
              ? rawStatus === 'killed'
                ? 'stopped'
                : rawStatus
              : 'completed'

            const usageMatch = notificationText.match(
              /<usage>([\s\S]*?)<\/usage>/,
            )
            const usageContent = usageMatch?.[1] ?? ''
            const totalTokensMatch = usageContent.match(
              /<total_tokens>(\d+)<\/total_tokens>/,
            )
            const toolUsesMatch = usageContent.match(
              /<tool_uses>(\d+)<\/tool_uses>/,
            )
            const durationMsMatch = usageContent.match(
              /<duration_ms>(\d+)<\/duration_ms>/,
            )

            // Only emit a task_notification SDK event when a <status> tag is
            // present — that means this is a terminal notification (completed/
            // failed/stopped). Stream events from enqueueStreamEvent carry no
            // <status> (they're progress pings); emitting them here would
            // default to 'completed' and falsely close the task for SDK
            // consumers. Terminal bookends are now emitted directly via
            // emitTaskTerminatedSdk, so skipping statusless events is safe.
            if (statusMatch) {
              output.enqueue({
                type: 'system',
                subtype: 'task_notification',
                task_id: taskIdMatch?.[1] ?? '',
                tool_use_id: toolUseIdMatch?.[1],
                status,
                output_file: outputFileMatch?.[1] ?? '',
                summary: summaryMatch?.[1] ?? '',
                usage:
                  totalTokensMatch && toolUsesMatch
                    ? {
                        total_tokens: parseInt(totalTokensMatch[1]!, 10),
                        tool_uses: parseInt(toolUsesMatch[1]!, 10),
                        duration_ms: durationMsMatch
                          ? parseInt(durationMsMatch[1]!, 10)
                          : 0,
                      }
                    : undefined,
                session_id: getSessionId(),
                uuid: randomUUID(),
              })
            }
            // No continue -- fall through to ask() so the model processes the result
          }

          const input = command.value

          if (structuredIO instanceof RemoteIO && command.mode === 'prompt') {
            logEvent('tengu_bridge_message_received', {
              is_repl: false,
            })
          }

          // Abort any in-flight suggestion generation and track acceptance
          suggestionState.abortController?.abort()
          suggestionState.abortController = null
          suggestionState.pendingSuggestion = null
          suggestionState.pendingLastEmittedEntry = null
          if (suggestionState.lastEmitted) {
            if (command.mode === 'prompt') {
              // SDK user messages enqueue ContentBlockParam[], not a plain string
              const inputText =
                typeof input === 'string'
                  ? input
                  : (
                      input.find(b => b.type === 'text') as
                        | { type: 'text'; text: string }
                        | undefined
                    )?.text
              if (typeof inputText === 'string') {
                logSuggestionOutcome(
                  suggestionState.lastEmitted.text,
                  inputText,
                  suggestionState.lastEmitted.emittedAt,
                  suggestionState.lastEmitted.promptId,
                  suggestionState.lastEmitted.generationRequestId,
                )
              }
              suggestionState.lastEmitted = null
            }
          }

          abortController = createAbortController()
          const turnStartTime = feature('FILE_PERSISTENCE')
            ? Date.now()
            : undefined

          headlessProfilerCheckpoint('before_ask')
          startQueryProfile()
          // Per-iteration ALS context so bg agents spawned inside ask()
          // inherit workload across their detached awaits. In-process cron
          // stamps cmd.workload; the SDK --workload flag is options.workload.
          // const-capture: TS loses `while ((command = dequeue()))` narrowing
          // inside the closure.
          const cmd = command
          await runWithWorkload(cmd.workload ?? options.workload, async () => {
            for await (const message of ask({
              commands: uniqBy(
                [...currentCommands, ...appState.mcp.commands],
                'name',
              ),
              prompt: input,
              promptUuid: cmd.uuid,
              isMeta: cmd.isMeta,
              cwd: cwd(),
              tools: allTools,
              verbose: options.verbose,
              mcpClients: allMcpClients,
              thinkingConfig: options.thinkingConfig,
              maxTurns: options.maxTurns,
              maxBudgetUsd: options.maxBudgetUsd,
              taskBudget: options.taskBudget,
              canUseTool,
              userSpecifiedModel: activeUserSpecifiedModel,
              fallbackModel: options.fallbackModel,
              jsonSchema: getInitJsonSchema() ?? options.jsonSchema,
              mutableMessages,
              getReadFileCache: () =>
                pendingSeeds.size === 0
                  ? readFileState
                  : mergeFileStateCaches(readFileState, pendingSeeds),
              setReadFileCache: cache => {
                readFileState = cache
                for (const [path, seed] of pendingSeeds.entries()) {
                  const existing = readFileState.get(path)
                  if (!existing || seed.timestamp > existing.timestamp) {
                    readFileState.set(path, seed)
                  }
                }
                pendingSeeds.clear()
              },
              customSystemPrompt: options.systemPrompt,
              appendSystemPrompt: options.appendSystemPrompt,
              getAppState,
              setAppState,
              abortController,
              replayUserMessages: options.replayUserMessages,
              includePartialMessages: options.includePartialMessages,
              handleElicitation: (serverName, params, elicitSignal) =>
                structuredIO.handleElicitation(
                  serverName,
                  params.message,
                  undefined,
                  elicitSignal,
                  params.mode,
                  params.url,
                  'elicitationId' in params ? params.elicitationId : undefined,
                ),
              agents: currentAgents,
              orphanedPermission: cmd.orphanedPermission,
              setSDKStatus: status => {
                output.enqueue({
                  type: 'system',
                  subtype: 'status',
                  status,
                  session_id: getSessionId(),
                  uuid: randomUUID(),
                })
              },
            })) {
              // Forward messages to bridge incrementally (mid-turn) so
              // claude.ai sees progress and the connection stays alive
              // while blocked on permission requests.
              forwardMessagesToBridge()

              if (message.type === 'result') {
                // Flush pending SDK events so they appear before result on the stream.
                for (const event of drainSdkEvents()) {
                  output.enqueue(event)
                }

                // Hold-back: don't emit result while background agents are running
                const currentState = getAppState()
                if (
                  getRunningTasks(currentState).some(
                    t =>
                      (t.type === 'local_agent' ||
                        t.type === 'local_workflow') &&
                      isBackgroundTask(t),
                  )
                ) {
                  heldBackResult = message
                } else {
                  heldBackResult = null
                  output.enqueue(message)
                }
              } else {
                // Flush SDK events (task_started, task_progress) so background
                // agent progress is streamed in real-time, not batched until result.
                for (const event of drainSdkEvents()) {
                  output.enqueue(event)
                }
                output.enqueue(message)
              }
            }
          }) // end runWithWorkload

          for (const uuid of batchUuids) {
            notifyCommandLifecycle(uuid, 'completed')
          }

          // Forward messages to bridge after each turn
          forwardMessagesToBridge()
          bridgeHandle?.sendResult()

          if (feature('FILE_PERSISTENCE') && turnStartTime !== undefined) {
            void executeFilePersistence(
              turnStartTime,
              abortController.signal,
              result => {
                output.enqueue({
                  type: 'system' as const,
                  subtype: 'files_persisted' as const,
                  files: result.files,
                  failed: result.failed,
                  processed_at: new Date().toISOString(),
                  uuid: randomUUID(),
                  session_id: getSessionId(),
                })
              },
            )
          }

          // Generate and emit prompt suggestion for SDK consumers
          if (
            options.promptSuggestions &&
            !isEnvDefinedFalsy(process.env.CLAUDE_CODE_ENABLE_PROMPT_SUGGESTION)
          ) {
            // TS narrows suggestionState to never in the while loop body;
            // cast via unknown to reset narrowing.
            const state = suggestionState as unknown as typeof suggestionState
            state.abortController?.abort()
            const localAbort = new AbortController()
            suggestionState.abortController = localAbort

            const cacheSafeParams = getLastCacheSafeParams()
            if (!cacheSafeParams) {
              logSuggestionSuppressed(
                'sdk_no_params',
                undefined,
                undefined,
                'sdk',
              )
            } else {
              // Use a ref object so the IIFE's finally can compare against its own
              // promise without a self-reference (which upsets TypeScript's flow analysis).
              const ref: { promise: Promise<void> | null } = { promise: null }
              ref.promise = (async () => {
                try {
                  const result = await tryGenerateSuggestion(
                    localAbort,
                    mutableMessages,
                    getAppState,
                    cacheSafeParams,
                    'sdk',
                  )
                  if (!result || localAbort.signal.aborted) return
                  const suggestionMsg = {
                    type: 'prompt_suggestion' as const,
                    suggestion: result.suggestion,
                    uuid: randomUUID(),
                    session_id: getSessionId(),
                  }
                  const lastEmittedEntry = {
                    text: result.suggestion,
                    emittedAt: Date.now(),
                    promptId: result.promptId,
                    generationRequestId: result.generationRequestId,
                  }
                  // Defer emission if the result is being held for background agents,
                  // so that prompt_suggestion always arrives after result.
                  // Only set lastEmitted when the suggestion is actually delivered
                  // to the consumer; deferred suggestions may be discarded before
                  // delivery if a new command arrives first.
                  if (heldBackResult) {
                    suggestionState.pendingSuggestion = suggestionMsg
                    suggestionState.pendingLastEmittedEntry = {
                      text: lastEmittedEntry.text,
                      promptId: lastEmittedEntry.promptId,
                      generationRequestId: lastEmittedEntry.generationRequestId,
                    }
                  } else {
                    suggestionState.lastEmitted = lastEmittedEntry
                    output.enqueue(suggestionMsg)
                  }
                } catch (error) {
                  if (
                    error instanceof Error &&
                    (error.name === 'AbortError' ||
                      error.name === 'APIUserAbortError')
                  ) {
                    logSuggestionSuppressed(
                      'aborted',
                      undefined,
                      undefined,
                      'sdk',
                    )
                    return
                  }
                  logError(toError(error))
                } finally {
                  if (suggestionState.inflightPromise === ref.promise) {
                    suggestionState.inflightPromise = null
                  }
                }
              })()
              suggestionState.inflightPromise = ref.promise
            }
          }

          // Log headless profiler metrics for this turn and start next turn
          logHeadlessProfilerTurn()
          logQueryProfileReport()
          headlessProfilerStartTurn()
        }
      }

      // Use a do-while loop to drain commands and then wait for any
      // background agents that are still running. When agents complete,
      // their notifications are enqueued and the loop re-drains.
      do {
        // Drain SDK events (task_started, task_progress) before command queue
        // so progress events precede task_notification on the stream.
        for (const event of drainSdkEvents()) {
          output.enqueue(event)
        }

        runPhase = 'draining_commands'
        await drainCommandQueue()

        // Check for running background tasks before exiting.
        // Exclude in_process_teammate — teammates are long-lived by design
        // (status: 'running' for their whole lifetime, cleaned up by the
        // shutdown protocol, not by transitioning to 'completed'). Waiting
        // on them here loops forever (gh-30008). Same exclusion already
        // exists at useBackgroundTaskNavigation.ts:55 for the same reason;
        // L1839 above is already narrower (type === 'local_agent') so it
        // doesn't hit this.
        waitingForAgents = false
        {
          const state = getAppState()
          const hasRunningBg = getRunningTasks(state).some(
            t => isBackgroundTask(t) && t.type !== 'in_process_teammate',
          )
          const hasMainThreadQueued = peek(isMainThread) !== undefined
          if (hasRunningBg || hasMainThreadQueued) {
            waitingForAgents = true
            if (!hasMainThreadQueued) {
              runPhase = 'waiting_for_agents'
              // No commands ready yet, wait for tasks to complete
              await sleep(100)
            }
            // Loop back to drain any newly queued commands
          }
        }
      } while (waitingForAgents)

      if (heldBackResult) {
        output.enqueue(heldBackResult)
        heldBackResult = null
        if (suggestionState.pendingSuggestion) {
          output.enqueue(suggestionState.pendingSuggestion)
          // Now that the suggestion is actually delivered, record it for acceptance tracking
          if (suggestionState.pendingLastEmittedEntry) {
            suggestionState.lastEmitted = {
              ...suggestionState.pendingLastEmittedEntry,
              emittedAt: Date.now(),
            }
            suggestionState.pendingLastEmittedEntry = null
          }
          suggestionState.pendingSuggestion = null
        }
      }
    } catch (error) {
      // Emit error result message before shutting down
      // Write directly to structuredIO to ensure immediate delivery
      try {
        await structuredIO.write({
          type: 'result',
          subtype: 'error_during_execution',
          duration_ms: 0,
          duration_api_ms: 0,
          is_error: true,
          num_turns: 0,
          stop_reason: null,
          session_id: getSessionId(),
          total_cost_usd: 0,
          usage: EMPTY_USAGE,
          modelUsage: {},
          permission_denials: [],
          uuid: randomUUID(),
          errors: [
            errorMessage(error),
            ...getInMemoryErrors().map(_ => _.error),
          ],
        })
      } catch {
        // If we can't emit the error result, continue with shutdown anyway
      }
      suggestionState.abortController?.abort()
      gracefulShutdownSync(1)
      return
    } finally {
      runPhase = 'finally_flush'
      // Flush pending internal events before going idle
      await structuredIO.flushInternalEvents()
      runPhase = 'finally_post_flush'
      if (!isShuttingDown()) {
        notifySessionStateChanged('idle')
        // Drain so the idle session_state_changed SDK event (plus any
        // terminal task_notification bookends emitted during bg-agent
        // teardown) reach the output stream before we block on the next
        // command. The do-while drain above only runs while
        // waitingForAgents; once we're here the next drain would be the
        // top of the next run(), which won't come if input is idle.
        for (const event of drainSdkEvents()) {
          output.enqueue(event)
        }
      }
      running = false
      // Start idle timer when we finish processing and are waiting for input
      idleTimeout.start()
    }

    // Proactive tick: if proactive is active and queue is empty, inject a tick
    if (
      (feature('PROACTIVE') || feature('KAIROS')) &&
      proactiveModule?.isProactiveActive() &&
      !proactiveModule.isProactivePaused()
    ) {
      if (peek(isMainThread) === undefined && !inputClosed) {
        scheduleProactiveTick!()
        return
      }
    }

    // Re-check the queue after releasing the mutex. A message may have
    // arrived (and called run()) between the last dequeue() returning
    // undefined and `running = false` above. In that case the caller
    // saw `running === true` and returned immediately, leaving the
    // message stranded in the queue with no one to process it.
    if (peek(isMainThread) !== undefined) {
      void run()
      return
    }

    // Check for unread teammate messages and process them
    // This mirrors what useInboxPoller does in interactive REPL mode
    // Poll until no more messages (teammates may still be working)
    {
      const currentAppState = getAppState()
      const teamContext = currentAppState.teamContext

      if (teamContext && isTeamLead(teamContext)) {
        const agentName = 'team-lead'

        // Poll for messages while teammates are active
        // This is needed because teammates may send messages while we're waiting
        // Keep polling until the team is shut down
        const POLL_INTERVAL_MS = 500

        while (true) {
          // Check if teammates are still active
          const refreshedState = getAppState()
          const hasActiveTeammates =
            hasActiveInProcessTeammates(refreshedState) ||
            (refreshedState.teamContext &&
              Object.keys(refreshedState.teamContext.teammates).length > 0)

          if (!hasActiveTeammates) {
            logForDebugging(
              '[print.ts] No more active teammates, stopping poll',
            )
            break
          }

          const unread = await readUnreadMessages(
            agentName,
            refreshedState.teamContext?.teamName,
          )

          if (unread.length > 0) {
            logForDebugging(
              `[print.ts] Team-lead found ${unread.length} unread messages`,
            )

            // Mark as read immediately to avoid duplicate processing
            await markMessagesAsRead(
              agentName,
              refreshedState.teamContext?.teamName,
            )

            // Process shutdown_approved messages - remove teammates from team file
            // This mirrors what useInboxPoller does in interactive mode (lines 546-606)
            const teamName = refreshedState.teamContext?.teamName
            for (const m of unread) {
              const shutdownApproval = isShutdownApproved(m.text)
              if (shutdownApproval && teamName) {
                const teammateToRemove = shutdownApproval.from
                logForDebugging(
                  `[print.ts] Processing shutdown_approved from ${teammateToRemove}`,
                )

                // Find the teammate ID by name
                const teammateId = refreshedState.teamContext?.teammates
                  ? Object.entries(refreshedState.teamContext.teammates).find(
                      ([, t]) => t.name === teammateToRemove,
                    )?.[0]
                  : undefined

                if (teammateId) {
                  // Remove from team file
                  removeTeammateFromTeamFile(teamName, {
                    agentId: teammateId,
                    name: teammateToRemove,
                  })
                  logForDebugging(
                    `[print.ts] Removed ${teammateToRemove} from team file`,
                  )

                  // Unassign tasks owned by this teammate
                  await unassignTeammateTasks(
                    teamName,
                    teammateId,
                    teammateToRemove,
                    'shutdown',
                  )

                  // Remove from teamContext in AppState
                  setAppState(prev => {
                    if (!prev.teamContext?.teammates) return prev
                    if (!(teammateId in prev.teamContext.teammates)) return prev
                    const { [teammateId]: _, ...remainingTeammates } =
                      prev.teamContext.teammates
                    return {
                      ...prev,
                      teamContext: {
                        ...prev.teamContext,
                        teammates: remainingTeammates,
                      },
                    }
                  })
                }
              }
            }

            // Format messages same as useInboxPoller
            const formatted = unread
              .map(
                (m: { from: string; text: string; color?: string }) =>
                  `<${TEAMMATE_MESSAGE_TAG} teammate_id="${m.from}"${m.color ? ` color="${m.color}"` : ''}>\n${m.text}\n</${TEAMMATE_MESSAGE_TAG}>`,
              )
              .join('\n\n')

            // Enqueue and process
            enqueue({
              mode: 'prompt',
              value: formatted,
              uuid: randomUUID(),
            })
            void run()
            return // run() will come back here after processing
          }

          // No messages - check if we need to prompt for shutdown
          // If input is closed and teammates are active, inject shutdown prompt once
          if (inputClosed && !shutdownPromptInjected) {
            shutdownPromptInjected = true
            logForDebugging(
              '[print.ts] Input closed with active teammates, injecting shutdown prompt',
            )
            enqueue({
              mode: 'prompt',
              value: SHUTDOWN_TEAM_PROMPT,
              uuid: randomUUID(),
            })
            void run()
            return // run() will come back here after processing
          }

          // Wait and check again
          await sleep(POLL_INTERVAL_MS)
        }
      }
    }

    if (inputClosed) {
      // Check for active swarm that needs shutdown
      const hasActiveSwarm = await (async () => {
        // Wait for any working in-process team members to finish
        const currentAppState = getAppState()
        if (hasWorkingInProcessTeammates(currentAppState)) {
          await waitForTeammatesToBecomeIdle(setAppState, currentAppState)
        }

        // Re-fetch state after potential wait
        const refreshedAppState = getAppState()
        const refreshedTeamContext = refreshedAppState.teamContext
        const hasTeamMembersNotCleanedUp =
          refreshedTeamContext &&
          Object.keys(refreshedTeamContext.teammates).length > 0

        return (
          hasTeamMembersNotCleanedUp ||
          hasActiveInProcessTeammates(refreshedAppState)
        )
      })()

      if (hasActiveSwarm) {
        // Team members are idle or pane-based - inject prompt to shut down team
        enqueue({
          mode: 'prompt',
          value: SHUTDOWN_TEAM_PROMPT,
          uuid: randomUUID(),
        })
        void run()
      } else {
        // Wait for any in-flight push suggestion before closing the output stream.
        if (suggestionState.inflightPromise) {
          await Promise.race([suggestionState.inflightPromise, sleep(5000)])
        }
        suggestionState.abortController?.abort()
        suggestionState.abortController = null
        await finalizePendingAsyncHooks()
        unsubscribeSkillChanges()
        unsubscribeAuthStatus?.()
        statusListeners.delete(rateLimitListener)
        output.done()
      }
    }
  }

  // Set up UDS inbox callback so the query loop is kicked off
  // when a message arrives via the UDS socket in headless mode.
  if (feature('UDS_INBOX')) {
    /* eslint-disable @typescript-eslint/no-require-imports */
    const { setOnEnqueue } = require('../utils/udsMessaging.js')
    /* eslint-enable @typescript-eslint/no-require-imports */
    setOnEnqueue(() => {
      if (!inputClosed) {
        void run()
      }
    })
  }

  // Cron scheduler: runs scheduled_tasks.json tasks in SDK/-p mode.
  // Mirrors REPL's useScheduledTasks hook. Fired prompts enqueue + kick
  // off run() directly — unlike REPL, there's no queue subscriber here
  // that drains on enqueue while idle. The run() mutex makes this safe
  // during an active turn: the call no-ops and the post-run recheck at
  // the end of run() picks up the queued command.
  let cronScheduler: import('../utils/cronScheduler.js').CronScheduler | null =
    null
  if (
    feature('AGENT_TRIGGERS') &&
    cronSchedulerModule &&
    cronGate?.isKairosCronEnabled()
  ) {
    cronScheduler = cronSchedulerModule.createCronScheduler({
      onFire: prompt => {
        if (inputClosed) return
        enqueue({
          mode: 'prompt',
          value: prompt,
          uuid: randomUUID(),
          priority: 'later',
          // System-generated — matches useScheduledTasks.ts REPL equivalent.
          // Without this, messages.ts metaProp eval is {} → prompt leaks
          // into visible transcript when cron fires mid-turn in -p mode.
          isMeta: true,
          // Threaded to cc_workload= in the billing-header attribution block
          // so the API can serve cron requests at lower QoS. drainCommandQueue
          // reads this per-iteration and hoists it into bootstrap state for
          // the ask() call.
          workload: WORKLOAD_CRON,
        })
        void run()
      },
      isLoading: () => running || inputClosed,
      getJitterConfig: cronJitterConfigModule?.getCronJitterConfig,
      isKilled: () => !cronGate?.isKairosCronEnabled(),
    })
    cronScheduler.start()
  }

  const sendControlResponseSuccess = function (
    message: SDKControlRequest,
    response?: Record<string, unknown>,
  ) {
    output.enqueue({
      type: 'control_response',
      response: {
        subtype: 'success',
        request_id: message.request_id,
        response: response,
      },
    })
  }

  const sendControlResponseError = function (
    message: SDKControlRequest,
    errorMessage: string,
  ) {
    output.enqueue({
      type: 'control_response',
      response: {
        subtype: 'error',
        request_id: message.request_id,
        error: errorMessage,
      },
    })
  }

  // Handle unexpected permission responses by looking up the unresolved tool
  // call in the transcript and executing it
  const handledOrphanedToolUseIds = new Set<string>()
  structuredIO.setUnexpectedResponseCallback(async message => {
    await handleOrphanedPermissionResponse({
      message,
      setAppState,
      handledToolUseIds: handledOrphanedToolUseIds,
      onEnqueued: () => {
        // The first message of a session might be the orphaned permission
        // check rather than a user prompt, so kick off the loop.
        void run()
      },
    })
  })

  // Track active OAuth flows per server so we can abort a previous flow
  // when a new mcp_authenticate request arrives for the same server.
  const activeOAuthFlows = new Map<string, AbortController>()
  // Track manual callback URL submit functions for active OAuth flows.
  // Used when localhost is not reachable (e.g., browser-based IDEs).
  const oauthCallbackSubmitters = new Map<
    string,
    (callbackUrl: string) => void
  >()
  // Track servers where the manual callback was actually invoked (so the
  // automatic reconnect path knows to skip — the extension will reconnect).
  const oauthManualCallbackUsed = new Set<string>()
  // Track OAuth auth-only promises so mcp_oauth_callback_url can await
  // token exchange completion. Reconnect is handled separately by the
  // extension via handleAuthDone → mcp_reconnect.
  const oauthAuthPromises = new Map<string, Promise<void>>()

  // In-flight Anthropic OAuth flow (claude_authenticate). Single-slot: a
  // second authenticate request cleans up the first. The service holds the
  // PKCE verifier + localhost listener; the promise settles after
  // installOAuthTokens — after it resolves, the in-process memoized token
  // cache is already cleared and the next API call picks up the new creds.
  let claudeOAuth: {
    service: OAuthService
    flow: Promise<void>
  } | null = null

  // This is essentially spawning a parallel async task- we have two
  // running in parallel- one reading from stdin and adding to the
  // queue to be processed and another reading from the queue,
  // processing and returning the result of the generation.
  // The process is complete when the input stream completes and
  // the last generation of the queue has complete.
  void (async () => {
    let initialized = false
    logForDiagnosticsNoPII('info', 'cli_message_loop_started')
    for await (const message of structuredIO.structuredInput) {
      // Non-user events are handled inline (no queue). started→completed in
      // the same tick carries no information, so only fire completed.
      // control_response is reported by StructuredIO.processLine (which also
      // sees orphans that never yield here).
      const eventId = 'uuid' in message ? message.uuid : undefined
      if (
        eventId &&
        message.type !== 'user' &&
        message.type !== 'control_response'
      ) {
        notifyCommandLifecycle(eventId, 'completed')
      }

      if (message.type === 'control_request') {
        if (message.request.subtype === 'interrupt') {
          // Track escapes for attribution (ant-only feature)
          if (feature('COMMIT_ATTRIBUTION')) {
            setAppState(prev => ({
              ...prev,
              attribution: {
                ...prev.attribution,
                escapeCount: prev.attribution.escapeCount + 1,
              },
            }))
          }
          if (abortController) {
            abortController.abort()
          }
          suggestionState.abortController?.abort()
          suggestionState.abortController = null
          suggestionState.lastEmitted = null
          suggestionState.pendingSuggestion = null
          sendControlResponseSuccess(message)
        } else if (message.request.subtype === 'end_session') {
          logForDebugging(
            `[print.ts] end_session received, reason=${message.request.reason ?? 'unspecified'}`,
          )
          if (abortController) {
            abortController.abort()
          }
          suggestionState.abortController?.abort()
          suggestionState.abortController = null
          suggestionState.lastEmitted = null
          suggestionState.pendingSuggestion = null
          sendControlResponseSuccess(message)
          break // exits for-await → falls through to inputClosed=true drain below
        } else if (message.request.subtype === 'initialize') {
          // SDK MCP server names from the initialize message
          // Populated by both browser and ProcessTransport sessions
          if (
            message.request.sdkMcpServers &&
            message.request.sdkMcpServers.length > 0
          ) {
            for (const serverName of message.request.sdkMcpServers) {
              // Create placeholder config for SDK MCP servers
              // The actual server connection is managed by the SDK Query class
              sdkMcpConfigs[serverName] = {
                type: 'sdk',
                name: serverName,
              }
            }
          }

          await handleInitializeRequest(
            message.request,
            message.request_id,
            initialized,
            output,
            commands,
            modelInfos,
            structuredIO,
            !!options.enableAuthStatus,
            options,
            agents,
            getAppState,
          )

          // Enable prompt suggestions in AppState when SDK consumer opts in.
          // shouldEnablePromptSuggestion() returns false for non-interactive
          // sessions, but the SDK consumer explicitly requested suggestions.
          if (message.request.promptSuggestions) {
            setAppState(prev => {
              if (prev.promptSuggestionEnabled) return prev
              return { ...prev, promptSuggestionEnabled: true }
            })
          }

          if (
            message.request.agentProgressSummaries &&
            getFeatureValue_CACHED_MAY_BE_STALE('tengu_slate_prism', true)
          ) {
            setSdkAgentProgressSummariesEnabled(true)
          }

          initialized = true

          // If the auto-resume logic pre-enqueued a command, drain it now
          // that initialize has set up systemPrompt, agents, hooks, etc.
          if (hasCommandsInQueue()) {
            void run()
          }
        } else if (message.request.subtype === 'set_permission_mode') {
          const m = message.request // for typescript (TODO: use readonly types to avoid this)
          setAppState(prev => ({
            ...prev,
            toolPermissionContext: handleSetPermissionMode(
              m,
              message.request_id,
              prev.toolPermissionContext,
              output,
            ),
            isUltraplanMode: m.ultraplan ?? prev.isUltraplanMode,
          }))
          // handleSetPermissionMode sends the control_response; the
          // notifySessionMetadataChanged that used to follow here is
          // now fired by onChangeAppState (with externalized mode name).
        } else if (message.request.subtype === 'set_model') {
          const requestedModel = message.request.model ?? 'default'
          const model =
            requestedModel === 'default'
              ? getDefaultMainLoopModel()
              : requestedModel
          activeUserSpecifiedModel = model
          setMainLoopModelOverride(model)
          notifySessionMetadataChanged({ model })
          injectModelSwitchBreadcrumbs(requestedModel, model)

          sendControlResponseSuccess(message)
        } else if (message.request.subtype === 'set_max_thinking_tokens') {
          if (message.request.max_thinking_tokens === null) {
            options.thinkingConfig = undefined
          } else if (message.request.max_thinking_tokens === 0) {
            options.thinkingConfig = { type: 'disabled' }
          } else {
            options.thinkingConfig = {
              type: 'enabled',
              budgetTokens: message.request.max_thinking_tokens,
            }
          }
          sendControlResponseSuccess(message)
        } else if (message.request.subtype === 'mcp_status') {
          sendControlResponseSuccess(message, {
            mcpServers: buildMcpServerStatuses(),
          })
        } else if (message.request.subtype === 'get_context_usage') {
          try {
            const appState = getAppState()
            const data = await collectContextData({
              messages: mutableMessages,
              getAppState,
              options: {
                mainLoopModel: getMainLoopModel(),
                tools: buildAllTools(appState),
                agentDefinitions: appState.agentDefinitions,
                customSystemPrompt: options.systemPrompt,
                appendSystemPrompt: options.appendSystemPrompt,
              },
            })
            sendControlResponseSuccess(message, { ...data })
          } catch (error) {
            sendControlResponseError(message, errorMessage(error))
          }
        } else if (message.request.subtype === 'mcp_message') {
          // Handle MCP notifications from SDK servers
          const mcpRequest = message.request
          const sdkClient = sdkClients.find(
            client => client.name === mcpRequest.server_name,
          )
          // Check client exists - dynamically added SDK servers may have
          // placeholder clients with null client until updateSdkMcp() runs
          if (
            sdkClient &&
            sdkClient.type === 'connected' &&
            sdkClient.client?.transport?.onmessage
          ) {
            sdkClient.client.transport.onmessage(mcpRequest.message)
          }
          sendControlResponseSuccess(message)
        } else if (message.request.subtype === 'rewind_files') {
          const appState = getAppState()
          const result = await handleRewindFiles(
            message.request.user_message_id as UUID,
            appState,
            setAppState,
            message.request.dry_run ?? false,
          )
          if (result.canRewind || message.request.dry_run) {
            sendControlResponseSuccess(message, result)
          } else {
            sendControlResponseError(
              message,
              result.error ?? 'Unexpected error',
            )
          }
        } else if (message.request.subtype === 'cancel_async_message') {
          const targetUuid = message.request.message_uuid
          const removed = dequeueAllMatching(cmd => cmd.uuid === targetUuid)
          sendControlResponseSuccess(message, {
            cancelled: removed.length > 0,
          })
        } else if (message.request.subtype === 'seed_read_state') {
          // Client observed a Read that was later removed from context (e.g.
          // by snip), so transcript-based seeding missed it. Queued into
          // pendingSeeds; applied at the next clone-replace boundary.
          try {
            // expandPath: all other readFileState writers normalize (~, relative,
            // session cwd vs process cwd). FileEditTool looks up by expandPath'd
            // key — a verbatim client path would miss.
            const normalizedPath = expandPath(message.request.path)
            // Check disk mtime before reading content. If the file changed
            // since the client's observation, readFile would return C_current
            // but we'd store it with the client's M_observed — getChangedFiles
            // then sees disk > cache.timestamp, re-reads, diffs C_current vs
            // C_current = empty, emits no attachment, and the model is never
            // told about the C_observed → C_current change. Skipping the seed
            // makes Edit fail "file not read yet" → forces a fresh Read.
            // Math.floor matches FileReadTool and getFileModificationTime.
            const diskMtime = Math.floor((await stat(normalizedPath)).mtimeMs)
            if (diskMtime <= message.request.mtime) {
              const raw = await readFile(normalizedPath, 'utf-8')
              // Strip BOM + normalize CRLF→LF to match readFileInRange and
              // readFileSyncWithMetadata. FileEditTool's content-compare
              // fallback (for Windows mtime bumps without content change)
              // compares against LF-normalized disk reads.
              const content = (
                raw.charCodeAt(0) === 0xfeff ? raw.slice(1) : raw
              ).replaceAll('\r\n', '\n')
              pendingSeeds.set(normalizedPath, {
                content,
                timestamp: diskMtime,
                offset: undefined,
                limit: undefined,
              })
            }
          } catch {
            // ENOENT etc — skip seeding but still succeed
          }
          sendControlResponseSuccess(message)
        } else if (message.request.subtype === 'mcp_set_servers') {
          const { response, sdkServersChanged } = await applyMcpServerChanges(
            message.request.servers,
          )
          sendControlResponseSuccess(message, response)

          // Connect SDK servers AFTER response to avoid deadlock
          if (sdkServersChanged) {
            void updateSdkMcp()
          }
        } else if (message.request.subtype === 'reload_plugins') {
          try {
            if (
              feature('DOWNLOAD_USER_SETTINGS') &&
              (isEnvTruthy(process.env.CLAUDE_CODE_REMOTE) || getIsRemoteMode())
            ) {
              // Re-pull user settings so enabledPlugins pushed from the
              // user's local CLI take effect before the cache sweep.
              const applied = await redownloadUserSettings()
              if (applied) {
                settingsChangeDetector.notifyChange('userSettings')
              }
            }

            const r = await refreshActivePlugins(setAppState)

            const sdkAgents = currentAgents.filter(
              a => a.source === 'flagSettings',
            )
            currentAgents = [...r.agentDefinitions.allAgents, ...sdkAgents]

            // Reload succeeded — gather response data best-effort so a
            // read failure doesn't mask the successful state change.
            // allSettled so one failure doesn't discard the others.
            let plugins: SDKControlReloadPluginsResponse['plugins'] = []
            const [cmdsR, mcpR, pluginsR] = await Promise.allSettled([
              getCommands(cwd()),
              applyPluginMcpDiff(),
              loadAllPluginsCacheOnly(),
            ])
            if (cmdsR.status === 'fulfilled') {
              currentCommands = cmdsR.value
            } else {
              logError(cmdsR.reason)
            }
            if (mcpR.status === 'rejected') {
              logError(mcpR.reason)
            }
            if (pluginsR.status === 'fulfilled') {
              plugins = pluginsR.value.enabled.map(p => ({
                name: p.name,
                path: p.path,
                source: p.source,
              }))
            } else {
              logError(pluginsR.reason)
            }

            sendControlResponseSuccess(message, {
              commands: currentCommands
                .filter(cmd => cmd.userInvocable !== false)
                .map(cmd => ({
                  name: getCommandName(cmd),
                  description: formatDescriptionWithSource(cmd),
                  argumentHint: cmd.argumentHint || '',
                })),
              agents: currentAgents.map(a => ({
                name: a.agentType,
                description: a.whenToUse,
                model: a.model === 'inherit' ? undefined : a.model,
              })),
              plugins,
              mcpServers: buildMcpServerStatuses(),
              error_count: r.error_count,
            } satisfies SDKControlReloadPluginsResponse)
          } catch (error) {
            sendControlResponseError(message, errorMessage(error))
          }
        } else if (message.request.subtype === 'mcp_reconnect') {
          const currentAppState = getAppState()
          const { serverName } = message.request
          elicitationRegistered.delete(serverName)
          // Config-existence gate must cover the SAME sources as the
          // operations below. SDK-injected servers (query({mcpServers:{...}}))
          // and dynamically-added servers were missing here, so
          // toggleMcpServer/reconnect returned "Server not found" even though
          // the disconnect/reconnect would have worked (gh-31339 / CC-314).
          const config =
            getMcpConfigByName(serverName) ??
            mcpClients.find(c => c.name === serverName)?.config ??
            sdkClients.find(c => c.name === serverName)?.config ??
            dynamicMcpState.clients.find(c => c.name === serverName)?.config ??
            currentAppState.mcp.clients.find(c => c.name === serverName)
              ?.config ??
            null
          if (!config) {
            sendControlResponseError(message, `Server not found: ${serverName}`)
          } else {
            const result = await reconnectMcpServerImpl(serverName, config)
            // Update appState.mcp with the new client, tools, commands, and resources
            const prefix = getMcpPrefix(serverName)
            setAppState(prev => ({
              ...prev,
              mcp: {
                ...prev.mcp,
                clients: prev.mcp.clients.map(c =>
                  c.name === serverName ? result.client : c,
                ),
                tools: [
                  ...reject(prev.mcp.tools, t => t.name?.startsWith(prefix)),
                  ...result.tools,
                ],
                commands: [
                  ...reject(prev.mcp.commands, c =>
                    commandBelongsToServer(c, serverName),
                  ),
                  ...result.commands,
                ],
                resources:
                  result.resources && result.resources.length > 0
                    ? { ...prev.mcp.resources, [serverName]: result.resources }
                    : omit(prev.mcp.resources, serverName),
              },
            }))
            // Also update dynamicMcpState so run() picks up the new tools
            // on the next turn (run() reads dynamicMcpState, not appState)
            dynamicMcpState = {
              ...dynamicMcpState,
              clients: [
                ...dynamicMcpState.clients.filter(c => c.name !== serverName),
                result.client,
              ],
              tools: [
                ...dynamicMcpState.tools.filter(
                  t => !t.name?.startsWith(prefix),
                ),
                ...result.tools,
              ],
            }
            if (result.client.type === 'connected') {
              registerElicitationHandlers([result.client])
              reregisterChannelHandlerAfterReconnect(result.client)
              sendControlResponseSuccess(message)
            } else {
              const errorMessage =
                result.client.type === 'failed'
                  ? (result.client.error ?? 'Connection failed')
                  : `Server status: ${result.client.type}`
              sendControlResponseError(message, errorMessage)
            }
          }
        } else if (message.request.subtype === 'mcp_toggle') {
          const currentAppState = getAppState()
          const { serverName, enabled } = message.request
          elicitationRegistered.delete(serverName)
          // Gate must match the client-lookup spread below (which
          // includes sdkClients and dynamicMcpState.clients). Same fix as
          // mcp_reconnect above (gh-31339 / CC-314).
          const config =
            getMcpConfigByName(serverName) ??
            mcpClients.find(c => c.name === serverName)?.config ??
            sdkClients.find(c => c.name === serverName)?.config ??
            dynamicMcpState.clients.find(c => c.name === serverName)?.config ??
            currentAppState.mcp.clients.find(c => c.name === serverName)
              ?.config ??
            null

          if (!config) {
            sendControlResponseError(message, `Server not found: ${serverName}`)
          } else if (!enabled) {
            // Disabling: persist + disconnect (matches TUI toggleMcpServer behavior)
            setMcpServerEnabled(serverName, false)
            const client = [
              ...mcpClients,
              ...sdkClients,
              ...dynamicMcpState.clients,
              ...currentAppState.mcp.clients,
            ].find(c => c.name === serverName)
            if (client && client.type === 'connected') {
              await clearServerCache(serverName, config)
            }
            // Update appState.mcp to reflect disabled status and remove tools/commands/resources
            const prefix = getMcpPrefix(serverName)
            setAppState(prev => ({
              ...prev,
              mcp: {
                ...prev.mcp,
                clients: prev.mcp.clients.map(c =>
                  c.name === serverName
                    ? { name: serverName, type: 'disabled' as const, config }
                    : c,
                ),
                tools: reject(prev.mcp.tools, t => t.name?.startsWith(prefix)),
                commands: reject(prev.mcp.commands, c =>
                  commandBelongsToServer(c, serverName),
                ),
                resources: omit(prev.mcp.resources, serverName),
              },
            }))
            sendControlResponseSuccess(message)
          } else {
            // Enabling: persist + reconnect
            setMcpServerEnabled(serverName, true)
            const result = await reconnectMcpServerImpl(serverName, config)
            // Update appState.mcp with the new client, tools, commands, and resources
            // This ensures the LLM sees updated tools after enabling the server
            const prefix = getMcpPrefix(serverName)
            setAppState(prev => ({
              ...prev,
              mcp: {
                ...prev.mcp,
                clients: prev.mcp.clients.map(c =>
                  c.name === serverName ? result.client : c,
                ),
                tools: [
                  ...reject(prev.mcp.tools, t => t.name?.startsWith(prefix)),
                  ...result.tools,
                ],
                commands: [
                  ...reject(prev.mcp.commands, c =>
                    commandBelongsToServer(c, serverName),
                  ),
                  ...result.commands,
                ],
                resources:
                  result.resources && result.resources.length > 0
                    ? { ...prev.mcp.resources, [serverName]: result.resources }
                    : omit(prev.mcp.resources, serverName),
              },
            }))
            if (result.client.type === 'connected') {
              registerElicitationHandlers([result.client])
              reregisterChannelHandlerAfterReconnect(result.client)
              sendControlResponseSuccess(message)
            } else {
              const errorMessage =
                result.client.type === 'failed'
                  ? (result.client.error ?? 'Connection failed')
                  : `Server status: ${result.client.type}`
              sendControlResponseError(message, errorMessage)
            }
          }
        } else if (message.request.subtype === 'channel_enable') {
          const currentAppState = getAppState()
          handleChannelEnable(
            message.request_id,
            message.request.serverName,
            // Pool spread matches mcp_status — all three client sources.
            [
              ...currentAppState.mcp.clients,
              ...sdkClients,
              ...dynamicMcpState.clients,
            ],
            output,
          )
        } else if (message.request.subtype === 'mcp_authenticate') {
          const { serverName } = message.request
          const currentAppState = getAppState()
          const config =
            getMcpConfigByName(serverName) ??
            mcpClients.find(c => c.name === serverName)?.config ??
            currentAppState.mcp.clients.find(c => c.name === serverName)
              ?.config ??
            null
          if (!config) {
            sendControlResponseError(message, `Server not found: ${serverName}`)
          } else if (config.type !== 'sse' && config.type !== 'http') {
            sendControlResponseError(
              message,
              `Server type "${config.type}" does not support OAuth authentication`,
            )
          } else {
            try {
              // Abort any previous in-flight OAuth flow for this server
              activeOAuthFlows.get(serverName)?.abort()
              const controller = new AbortController()
              activeOAuthFlows.set(serverName, controller)

              // Capture the auth URL from the callback
              let resolveAuthUrl: (url: string) => void
              const authUrlPromise = new Promise<string>(resolve => {
                resolveAuthUrl = resolve
              })

              // Start the OAuth flow in the background
              const oauthPromise = performMCPOAuthFlow(
                serverName,
                config,
                url => resolveAuthUrl!(url),
                controller.signal,
                {
                  skipBrowserOpen: true,
                  onWaitingForCallback: submit => {
                    oauthCallbackSubmitters.set(serverName, submit)
                  },
                },
              )

              // Wait for the auth URL (or the flow to complete without needing redirect)
              const authUrl = await Promise.race([
                authUrlPromise,
                oauthPromise.then(() => null as string | null),
              ])

              if (authUrl) {
                sendControlResponseSuccess(message, {
                  authUrl,
                  requiresUserAction: true,
                })
              } else {
                sendControlResponseSuccess(message, {
                  requiresUserAction: false,
                })
              }

              // Store auth-only promise for mcp_oauth_callback_url handler.
              // Don't swallow errors — the callback handler needs to detect
              // auth failures and report them to the caller.
              oauthAuthPromises.set(serverName, oauthPromise)

              // Handle background completion — reconnect after auth.
              // When manual callback is used, skip the reconnect here;
              // the extension's handleAuthDone → mcp_reconnect handles it
              // (which also updates dynamicMcpState for tool registration).
              const fullFlowPromise = oauthPromise
                .then(async () => {
                  // Don't reconnect if the server was disabled during the OAuth flow
                  if (isMcpServerDisabled(serverName)) {
                    return
                  }
                  // Skip reconnect if the manual callback path was used —
                  // handleAuthDone will do it via mcp_reconnect (which
                  // updates dynamicMcpState for tool registration).
                  if (oauthManualCallbackUsed.has(serverName)) {
                    return
                  }
                  // Reconnect the server after successful auth
                  const result = await reconnectMcpServerImpl(
                    serverName,
                    config,
                  )
                  const prefix = getMcpPrefix(serverName)
                  setAppState(prev => ({
                    ...prev,
                    mcp: {
                      ...prev.mcp,
                      clients: prev.mcp.clients.map(c =>
                        c.name === serverName ? result.client : c,
                      ),
                      tools: [
                        ...reject(prev.mcp.tools, t =>
                          t.name?.startsWith(prefix),
                        ),
                        ...result.tools,
                      ],
                      commands: [
                        ...reject(prev.mcp.commands, c =>
                          commandBelongsToServer(c, serverName),
                        ),
                        ...result.commands,
                      ],
                      resources:
                        result.resources && result.resources.length > 0
                          ? {
                              ...prev.mcp.resources,
                              [serverName]: result.resources,
                            }
                          : omit(prev.mcp.resources, serverName),
                    },
                  }))
                  // Also update dynamicMcpState so run() picks up the new tools
                  // on the next turn (run() reads dynamicMcpState, not appState)
                  dynamicMcpState = {
                    ...dynamicMcpState,
                    clients: [
                      ...dynamicMcpState.clients.filter(
                        c => c.name !== serverName,
                      ),
                      result.client,
                    ],
                    tools: [
                      ...dynamicMcpState.tools.filter(
                        t => !t.name?.startsWith(prefix),
                      ),
                      ...result.tools,
                    ],
                  }
                })
                .catch(error => {
                  logForDebugging(
                    `MCP OAuth failed for ${serverName}: ${error}`,
                    { level: 'error' },
                  )
                })
                .finally(() => {
                  // Clean up only if this is still the active flow
                  if (activeOAuthFlows.get(serverName) === controller) {
                    activeOAuthFlows.delete(serverName)
                    oauthCallbackSubmitters.delete(serverName)
                    oauthManualCallbackUsed.delete(serverName)
                    oauthAuthPromises.delete(serverName)
                  }
                })
              void fullFlowPromise
            } catch (error) {
              sendControlResponseError(message, errorMessage(error))
            }
          }
        } else if (message.request.subtype === 'mcp_oauth_callback_url') {
          const { serverName, callbackUrl } = message.request
          const submit = oauthCallbackSubmitters.get(serverName)
          if (submit) {
            // Validate the callback URL before submitting. The submit
            // callback in auth.ts silently ignores URLs missing a code
            // param, which would leave the auth promise unresolved and
            // block the control message loop until timeout.
            let hasCodeOrError = false
            try {
              const parsed = new URL(callbackUrl)
              hasCodeOrError =
                parsed.searchParams.has('code') ||
                parsed.searchParams.has('error')
            } catch {
              // Invalid URL
            }
            if (!hasCodeOrError) {
              sendControlResponseError(
                message,
                'Invalid callback URL: missing authorization code. Please paste the full redirect URL including the code parameter.',
              )
            } else {
              oauthManualCallbackUsed.add(serverName)
              submit(callbackUrl)
              // Wait for auth (token exchange) to complete before responding.
              // Reconnect is handled by the extension via handleAuthDone →
              // mcp_reconnect (which updates dynamicMcpState for tools).
              const authPromise = oauthAuthPromises.get(serverName)
              if (authPromise) {
                try {
                  await authPromise
                  sendControlResponseSuccess(message)
                } catch (error) {
                  sendControlResponseError(
                    message,
                    error instanceof Error
                      ? error.message
                      : 'OAuth authentication failed',
                  )
                }
              } else {
                sendControlResponseSuccess(message)
              }
            }
          } else {
            sendControlResponseError(
              message,
              `No active OAuth flow for server: ${serverName}`,
            )
          }
        } else if (message.request.subtype === 'claude_authenticate') {
          // Anthropic OAuth over the control channel. The SDK client owns
          // the user's browser (we're headless in -p mode); we hand back
          // both URLs and wait. Automatic URL → localhost listener catches
          // the redirect if the browser is on this host; manual URL → the
          // success page shows "code#state" for claude_oauth_callback.
          const { loginWithClaudeAi } = message.request

          // Clean up any prior flow. cleanup() closes the localhost listener
          // and nulls the manual resolver. The prior `flow` promise is left
          // pending (AuthCodeListener.close() does not reject) but its object
          // graph becomes unreachable once the server handle is released and
          // is GC'd — no fd or port is held.
          claudeOAuth?.service.cleanup()

          logEvent('tengu_oauth_flow_start', {
            loginWithClaudeAi: loginWithClaudeAi ?? true,
          })

          const service = new OAuthService()
          let urlResolver!: (urls: {
            manualUrl: string
            automaticUrl: string
          }) => void
          const urlPromise = new Promise<{
            manualUrl: string
            automaticUrl: string
          }>(resolve => {
            urlResolver = resolve
          })

          const flow = service
            .startOAuthFlow(
              async (manualUrl, automaticUrl) => {
                // automaticUrl is always defined when skipBrowserOpen is set;
                // the signature is optional only for the existing single-arg callers.
                urlResolver({ manualUrl, automaticUrl: automaticUrl! })
              },
              {
                loginWithClaudeAi: loginWithClaudeAi ?? true,
                skipBrowserOpen: true,
              },
            )
            .then(async tokens => {
              // installOAuthTokens: performLogout (clear stale state) →
              // store profile → saveOAuthTokensIfNeeded → clearOAuthTokenCache
              // → clearAuthRelatedCaches. After this resolves, the memoized
              // getClaudeAIOAuthTokens in this process is invalidated; the
              // next API call re-reads keychain/file and works. No respawn.
              await installOAuthTokens(tokens)
              logEvent('tengu_oauth_success', {
                loginWithClaudeAi: loginWithClaudeAi ?? true,
              })
            })
            .finally(() => {
              service.cleanup()
              if (claudeOAuth?.service === service) {
                claudeOAuth = null
              }
            })

          claudeOAuth = { service, flow }

          // Attach the rejection handler before awaiting so a synchronous
          // startOAuthFlow failure doesn't surface as an unhandled rejection.
          // The claude_oauth_callback handler re-awaits flow for the manual
          // path and surfaces the real error to the client.
          void flow.catch(err =>
            logForDebugging(`claude_authenticate flow ended: ${err}`, {
              level: 'info',
            }),
          )

          try {
            // Race against flow: if startOAuthFlow rejects before calling
            // the authURLHandler (e.g. AuthCodeListener.start() fails with
            // EACCES or fd exhaustion), urlPromise would pend forever and
            // wedge the stdin loop. flow resolving first is unreachable in
            // practice (it's suspended on the same urls we're waiting for).
            const { manualUrl, automaticUrl } = await Promise.race([
              urlPromise,
              flow.then(() => {
                throw new Error(
                  'OAuth flow completed without producing auth URLs',
                )
              }),
            ])
            sendControlResponseSuccess(message, {
              manualUrl,
              automaticUrl,
            })
          } catch (error) {
            sendControlResponseError(message, errorMessage(error))
          }
        } else if (
          message.request.subtype === 'claude_oauth_callback' ||
          message.request.subtype === 'claude_oauth_wait_for_completion'
        ) {
          if (!claudeOAuth) {
            sendControlResponseError(
              message,
              'No active claude_authenticate flow',
            )
          } else {
            // Inject the manual code synchronously — must happen in stdin
            // message order so a subsequent claude_authenticate doesn't
            // replace the service before this code lands.
            if (message.request.subtype === 'claude_oauth_callback') {
              claudeOAuth.service.handleManualAuthCodeInput({
                authorizationCode: message.request.authorizationCode,
                state: message.request.state,
              })
            }
            // Detach the await — the stdin reader is serial and blocking
            // here deadlocks claude_oauth_wait_for_completion: flow may
            // only resolve via a future claude_oauth_callback on stdin,
            // which can't be read while we're parked. Capture the binding;
            // claudeOAuth is nulled in flow's own .finally.
            const { flow } = claudeOAuth
            void flow.then(
              () => {
                const accountInfo = getAccountInformation()
                sendControlResponseSuccess(message, {
                  account: {
                    email: accountInfo?.email,
                    organization: accountInfo?.organization,
                    subscriptionType: accountInfo?.subscription,
                    tokenSource: accountInfo?.tokenSource,
                    apiKeySource: accountInfo?.apiKeySource,
                    apiProvider: getAPIProvider(),
                  },
                })
              },
              (error: unknown) =>
                sendControlResponseError(message, errorMessage(error)),
            )
          }
        } else if (message.request.subtype === 'mcp_clear_auth') {
          const { serverName } = message.request
          const currentAppState = getAppState()
          const config =
            getMcpConfigByName(serverName) ??
            mcpClients.find(c => c.name === serverName)?.config ??
            currentAppState.mcp.clients.find(c => c.name === serverName)
              ?.config ??
            null
          if (!config) {
            sendControlResponseError(message, `Server not found: ${serverName}`)
          } else if (config.type !== 'sse' && config.type !== 'http') {
            sendControlResponseError(
              message,
              `Cannot clear auth for server type "${config.type}"`,
            )
          } else {
            await revokeServerTokens(serverName, config)
            const result = await reconnectMcpServerImpl(serverName, config)
            const prefix = getMcpPrefix(serverName)
            setAppState(prev => ({
              ...prev,
              mcp: {
                ...prev.mcp,
                clients: prev.mcp.clients.map(c =>
                  c.name === serverName ? result.client : c,
                ),
                tools: [
                  ...reject(prev.mcp.tools, t => t.name?.startsWith(prefix)),
                  ...result.tools,
                ],
                commands: [
                  ...reject(prev.mcp.commands, c =>
                    commandBelongsToServer(c, serverName),
                  ),
                  ...result.commands,
                ],
                resources:
                  result.resources && result.resources.length > 0
                    ? {
                        ...prev.mcp.resources,
                        [serverName]: result.resources,
                      }
                    : omit(prev.mcp.resources, serverName),
              },
            }))
            sendControlResponseSuccess(message, {})
          }
        } else if (message.request.subtype === 'apply_flag_settings') {
          // Snapshot the current model before applying — we need to detect
          // model switches so we can inject breadcrumbs and notify listeners.
          const prevModel = getMainLoopModel()

          // Merge the provided settings into the in-memory flag settings
          const existing = getFlagSettingsInline() ?? {}
          const incoming = message.request.settings
          // Shallow-merge top-level keys; getSettingsForSource handles
          // the deep merge with file-based flag settings via mergeWith.
          // JSON serialization drops `undefined`, so callers use `null`
          // to signal "clear this key". Convert nulls to deletions so
          // SettingsSchema().safeParse() doesn't reject the whole object
          // (z.string().optional() accepts string | undefined, not null).
          const merged = { ...existing, ...incoming }
          for (const key of Object.keys(merged)) {
            if (merged[key as keyof typeof merged] === null) {
              delete merged[key as keyof typeof merged]
            }
          }
          setFlagSettingsInline(merged)
          // Route through notifyChange so fanOut() resets the settings cache
          // before listeners run. The subscriber at :392 calls
          // applySettingsChange for us. Pre-#20625 this was a direct
          // applySettingsChange() call that relied on its own internal reset —
          // now that the reset is centralized in fanOut, a direct call here
          // would read stale cached settings and silently drop the update.
          // Bonus: going through notifyChange also tells the other subscribers
          // (loadPluginHooks, sandbox-adapter) about the change, which the
          // previous direct call skipped.
          settingsChangeDetector.notifyChange('flagSettings')

          // If the incoming settings include a model change, update the
          // override so getMainLoopModel() reflects it. The override has
          // higher priority than the settings cascade in
          // getUserSpecifiedModelSetting(), so without this update,
          // getMainLoopModel() returns the stale override and the model
          // change is silently ignored (matching set_model at :2811).
          if ('model' in incoming) {
            if (incoming.model != null) {
              setMainLoopModelOverride(String(incoming.model))
            } else {
              setMainLoopModelOverride(undefined)
            }
          }

          // If the model changed, inject breadcrumbs so the model sees the
          // mid-conversation switch, and notify metadata listeners (CCR).
          const newModel = getMainLoopModel()
          if (newModel !== prevModel) {
            activeUserSpecifiedModel = newModel
            const modelArg = incoming.model ? String(incoming.model) : 'default'
            notifySessionMetadataChanged({ model: newModel })
            injectModelSwitchBreadcrumbs(modelArg, newModel)
          }

          sendControlResponseSuccess(message)
        } else if (message.request.subtype === 'get_settings') {
          const currentAppState = getAppState()
          const model = getMainLoopModel()
          // modelSupportsEffort gate matches claude.ts — applied.effort must
          // mirror what actually goes to the API, not just what's configured.
          const effort = modelSupportsEffort(model)
            ? resolveAppliedEffort(model, currentAppState.effortValue)
            : undefined
          sendControlResponseSuccess(message, {
            ...getSettingsWithSources(),
            applied: {
              model,
              // Numeric effort (ant-only) → null; SDK schema is string-level only.
              effort: typeof effort === 'string' ? effort : null,
            },
          })
        } else if (message.request.subtype === 'stop_task') {
          const { task_id: taskId } = message.request
          try {
            await stopTask(taskId, {
              getAppState,
              setAppState,
            })
            sendControlResponseSuccess(message, {})
          } catch (error) {
            sendControlResponseError(message, errorMessage(error))
          }
        } else if (message.request.subtype === 'generate_session_title') {
          // Fire-and-forget so the Haiku call does not block the stdin loop
          // (which would delay processing of subsequent user messages /
          // interrupts for the duration of the API roundtrip).
          const { description, persist } = message.request
          // Reuse the live controller only if it has not already been aborted
          // (e.g. by interrupt()); an aborted signal would cause queryHaiku to
          // immediately throw APIUserAbortError → {title: null}.
          const titleSignal = (
            abortController && !abortController.signal.aborted
              ? abortController
              : createAbortController()
          ).signal
          void (async () => {
            try {
              const title = await generateSessionTitle(description, titleSignal)
              if (title && persist) {
                try {
                  saveAiGeneratedTitle(getSessionId() as UUID, title)
                } catch (e) {
                  logError(e)
                }
              }
              sendControlResponseSuccess(message, { title })
            } catch (e) {
              // Unreachable in practice — generateSessionTitle wraps its
              // own body and returns null, saveAiGeneratedTitle is wrapped
              // above. Propagate (not swallow) so unexpected failures are
              // visible to the SDK caller (hostComms.ts catches and logs).
              sendControlResponseError(message, errorMessage(e))
            }
          })()
        } else if (message.request.subtype === 'side_question') {
          // Same fire-and-forget pattern as generate_session_title above —
          // the forked agent's API roundtrip must not block the stdin loop.
          //
          // The snapshot captured by stopHooks (for querySource === 'sdk')
          // holds the exact systemPrompt/userContext/systemContext/messages
          // sent on the last main-thread turn. Reusing them gives a byte-
          // identical prefix → prompt cache hit.
          //
          // Fallback (resume before first turn completes — no snapshot yet):
          // rebuild from scratch. buildSideQuestionFallbackParams mirrors
          // QueryEngine.ts:ask()'s system prompt assembly (including
          // --system-prompt / --append-system-prompt) so the rebuilt prefix
          // matches in the common case. May still miss the cache for
          // coordinator mode or memory-mechanics extras — acceptable, the
          // alternative is the side question failing entirely.
          const { question } = message.request
          void (async () => {
            try {
              const saved = getLastCacheSafeParams()
              const cacheSafeParams = saved
                ? {
                    ...saved,
                    // If the last turn was interrupted, the snapshot holds an
                    // already-aborted controller; createChildAbortController in
                    // createSubagentContext would propagate it and the fork
                    // would die before sending a request. The controller is
                    // not part of the cache key — swapping in a fresh one is
                    // safe. Same guard as generate_session_title above.
                    toolUseContext: {
                      ...saved.toolUseContext,
                      abortController: createAbortController(),
                    },
                  }
                : await buildSideQuestionFallbackParams({
                    tools: buildAllTools(getAppState()),
                    commands: currentCommands,
                    mcpClients: [
                      ...getAppState().mcp.clients,
                      ...sdkClients,
                      ...dynamicMcpState.clients,
                    ],
                    messages: mutableMessages,
                    readFileState,
                    getAppState,
                    setAppState,
                    customSystemPrompt: options.systemPrompt,
                    appendSystemPrompt: options.appendSystemPrompt,
                    thinkingConfig: options.thinkingConfig,
                    agents: currentAgents,
                  })
              const result = await runSideQuestion({
                question,
                cacheSafeParams,
              })
              sendControlResponseSuccess(message, { response: result.response })
            } catch (e) {
              sendControlResponseError(message, errorMessage(e))
            }
          })()
        } else if (
          (feature('PROACTIVE') || feature('KAIROS')) &&
          (message.request as { subtype: string }).subtype === 'set_proactive'
        ) {
          const req = message.request as unknown as {
            subtype: string
            enabled: boolean
          }
          if (req.enabled) {
            if (!proactiveModule!.isProactiveActive()) {
              proactiveModule!.activateProactive('command')
              scheduleProactiveTick!()
            }
          } else {
            proactiveModule!.deactivateProactive()
          }
          sendControlResponseSuccess(message)
        } else if (message.request.subtype === 'remote_control') {
          if (message.request.enabled) {
            if (bridgeHandle) {
              // Already connected
              sendControlResponseSuccess(message, {
                session_url: getRemoteSessionUrl(
                  bridgeHandle.bridgeSessionId,
                  bridgeHandle.sessionIngressUrl,
                ),
                connect_url: buildBridgeConnectUrl(
                  bridgeHandle.environmentId,
                  bridgeHandle.sessionIngressUrl,
                ),
                environment_id: bridgeHandle.environmentId,
              })
            } else {
              // initReplBridge surfaces gate-failure reasons via
              // onStateChange('failed', detail) before returning null.
              // Capture so the control-response error is actionable
              // ("/login", "disabled by your organization's policy", etc.)
              // instead of a generic "initialization failed".
              let bridgeFailureDetail: string | undefined
              try {
                const { initReplBridge } = await import(
                  'src/bridge/initReplBridge.js'
                )
                const handle = await initReplBridge({
                  onInboundMessage(msg) {
                    const fields = extractInboundMessageFields(msg)
                    if (!fields) return
                    const { content, uuid } = fields
                    enqueue({
                      value: content,
                      mode: 'prompt' as const,
                      uuid,
                      skipSlashCommands: true,
                    })
                    void run()
                  },
                  onPermissionResponse(response) {
                    // Forward bridge permission responses into the
                    // stdin processing loop so they resolve pending
                    // permission requests from the SDK consumer.
                    structuredIO.injectControlResponse(response)
                  },
                  onInterrupt() {
                    abortController?.abort()
                  },
                  onSetModel(model) {
                    const resolved =
                      model === 'default' ? getDefaultMainLoopModel() : model
                    activeUserSpecifiedModel = resolved
                    setMainLoopModelOverride(resolved)
                  },
                  onSetMaxThinkingTokens(maxTokens) {
                    if (maxTokens === null) {
                      options.thinkingConfig = undefined
                    } else if (maxTokens === 0) {
                      options.thinkingConfig = { type: 'disabled' }
                    } else {
                      options.thinkingConfig = {
                        type: 'enabled',
                        budgetTokens: maxTokens,
                      }
                    }
                  },
                  onStateChange(state, detail) {
                    if (state === 'failed') {
                      bridgeFailureDetail = detail
                    }
                    logForDebugging(
                      `[bridge:sdk] State change: ${state}${detail ? ` — ${detail}` : ''}`,
                    )
                    output.enqueue({
                      type: 'system' as StdoutMessage['type'],
                      subtype: 'bridge_state' as string,
                      state,
                      detail,
                      uuid: randomUUID(),
                      session_id: getSessionId(),
                    } as StdoutMessage)
                  },
                  initialMessages:
                    mutableMessages.length > 0 ? mutableMessages : undefined,
                })
                if (!handle) {
                  sendControlResponseError(
                    message,
                    bridgeFailureDetail ??
                      'Remote Control initialization failed',
                  )
                } else {
                  bridgeHandle = handle
                  bridgeLastForwardedIndex = mutableMessages.length
                  // Forward permission requests to the bridge
                  structuredIO.setOnControlRequestSent(request => {
                    handle.sendControlRequest(request)
                  })
                  // Cancel stale bridge permission prompts when the SDK
                  // consumer resolves a can_use_tool request first.
                  structuredIO.setOnControlRequestResolved(requestId => {
                    handle.sendControlCancelRequest(requestId)
                  })
                  sendControlResponseSuccess(message, {
                    session_url: getRemoteSessionUrl(
                      handle.bridgeSessionId,
                      handle.sessionIngressUrl,
                    ),
                    connect_url: buildBridgeConnectUrl(
                      handle.environmentId,
                      handle.sessionIngressUrl,
                    ),
                    environment_id: handle.environmentId,
                  })
                }
              } catch (err) {
                sendControlResponseError(message, errorMessage(err))
              }
            }
          } else {
            // Disable
            if (bridgeHandle) {
              structuredIO.setOnControlRequestSent(undefined)
              structuredIO.setOnControlRequestResolved(undefined)
              await bridgeHandle.teardown()
              bridgeHandle = null
            }
            sendControlResponseSuccess(message)
          }
        } else {
          // Unknown control request subtype — send an error response so
          // the caller doesn't hang waiting for a reply that never comes.
          sendControlResponseError(
            message,
            `Unsupported control request subtype: ${(message.request as { subtype: string }).subtype}`,
          )
        }
        continue
      } else if (message.type === 'control_response') {
        // Replay control_response messages when replay mode is enabled
        if (options.replayUserMessages) {
          output.enqueue(message)
        }
        continue
      } else if (message.type === 'keep_alive') {
        // Silently ignore keep-alive messages
        continue
      } else if (message.type === 'update_environment_variables') {
        // Handled in structuredIO.ts, but TypeScript needs the type guard
        continue
      } else if (message.type === 'assistant' || message.type === 'system') {
        // History replay from bridge: inject into mutableMessages as
        // conversation context so the model sees prior turns.
        const internalMsgs = toInternalMessages([message])
        mutableMessages.push(...internalMsgs)
        // Echo assistant messages back so CCR displays them
        if (message.type === 'assistant' && options.replayUserMessages) {
          output.enqueue(message)
        }
        continue
      }
      // After handling control, keep-alive, env-var, assistant, and system
      // messages above, only user messages should remain.
      if (message.type !== 'user') {
        continue
      }

      // First prompt message implicitly initializes if not already done.
      initialized = true

      // Check for duplicate user message - skip if already processed
      if (message.uuid) {
        const sessionId = getSessionId() as UUID
        const existsInSession = await doesMessageExistInSession(
          sessionId,
          message.uuid,
        )

        // Check both historical duplicates (from file) and runtime duplicates (this session)
        if (existsInSession || receivedMessageUuids.has(message.uuid)) {
          logForDebugging(`Skipping duplicate user message: ${message.uuid}`)
          // Send acknowledgment for duplicate message if replay mode is enabled
          if (options.replayUserMessages) {
            logForDebugging(
              `Sending acknowledgment for duplicate user message: ${message.uuid}`,
            )
            output.enqueue({
              type: 'user',
              message: message.message,
              session_id: sessionId,
              parent_tool_use_id: null,
              uuid: message.uuid,
              timestamp: message.timestamp,
              isReplay: true,
            } as SDKUserMessageReplay)
          }
          // Historical dup = transcript already has this turn's output, so it
          // ran but its lifecycle was never closed (interrupted before ack).
          // Runtime dups don't need this — the original enqueue path closes them.
          if (existsInSession) {
            notifyCommandLifecycle(message.uuid, 'completed')
          }
          // Don't enqueue duplicate messages for execution
          continue
        }

        // Track this UUID to prevent runtime duplicates
        trackReceivedMessageUuid(message.uuid)
      }

      enqueue({
        mode: 'prompt' as const,
        // file_attachments rides the protobuf catchall from the web composer.
        // Same-ref no-op when absent (no 'file_attachments' key).
        value: await resolveAndPrepend(message, message.message.content),
        uuid: message.uuid,
        priority: message.priority,
      })
      // Increment prompt count for attribution tracking and save snapshot
      // The snapshot persists promptCount so it survives compaction
      if (feature('COMMIT_ATTRIBUTION')) {
        setAppState(prev => ({
          ...prev,
          attribution: incrementPromptCount(prev.attribution, snapshot => {
            void recordAttributionSnapshot(snapshot).catch(error => {
              logForDebugging(`Attribution: Failed to save snapshot: ${error}`)
            })
          }),
        }))
      }
      void run()
    }
    inputClosed = true
    cronScheduler?.stop()
    if (!running) {
      // If a push-suggestion is in-flight, wait for it to emit before closing
      // the output stream (5 s safety timeout to prevent hanging).
      if (suggestionState.inflightPromise) {
        await Promise.race([suggestionState.inflightPromise, sleep(5000)])
      }
      suggestionState.abortController?.abort()
      suggestionState.abortController = null
      await finalizePendingAsyncHooks()
      unsubscribeSkillChanges()
      unsubscribeAuthStatus?.()
      statusListeners.delete(rateLimitListener)
      output.done()
    }
  })()

  return output
}

/**
 * Creates a CanUseToolFn that incorporates a custom permission prompt tool.
 * This function converts the permissionPromptTool into a CanUseToolFn that can be used in ask.tsx
 */
export function createCanUseToolWithPermissionPrompt(
  permissionPromptTool: PermissionPromptTool,
): CanUseToolFn {
  const canUseTool: CanUseToolFn = async (
    tool,
    input,
    toolUseContext,
    assistantMessage,
    toolUseId,
    forceDecision,
  ) => {
    const mainPermissionResult =
      forceDecision ??
      (await hasPermissionsToUseTool(
        tool,
        input,
        toolUseContext,
        assistantMessage,
        toolUseId,
      ))

    // If the tool is allowed or denied, return the result
    if (
      mainPermissionResult.behavior === 'allow' ||
      mainPermissionResult.behavior === 'deny'
    ) {
      return mainPermissionResult
    }

    // Race the permission prompt tool against the abort signal.
    //
    // Why we need this: The permission prompt tool may block indefinitely waiting
    // for user input (e.g., via stdin or a UI dialog). If the user triggers an
    // interrupt (Ctrl+C), we need to detect it even while the tool is blocked.
    // Without this race, the abort check would only run AFTER the tool completes,
    // which may never happen if the tool is waiting for input that will never come.
    //
    // The second check (combinedSignal.aborted) handles a race condition where
    // abort fires after Promise.race resolves but before we reach this check.
    const { signal: combinedSignal, cleanup: cleanupAbortListener } =
      createCombinedAbortSignal(toolUseContext.abortController.signal)

    // Check if already aborted before starting the race
    if (combinedSignal.aborted) {
      cleanupAbortListener()
      return {
        behavior: 'deny',
        message: 'Permission prompt was aborted.',
        decisionReason: {
          type: 'permissionPromptTool' as const,
          permissionPromptToolName: tool.name,
          toolResult: undefined,
        },
      }
    }

    const abortPromise = new Promise<'aborted'>(resolve => {
      combinedSignal.addEventListener('abort', () => resolve('aborted'), {
        once: true,
      })
    })

    const toolCallPromise = permissionPromptTool.call(
      {
        tool_name: tool.name,
        input,
        tool_use_id: toolUseId,
      },
      toolUseContext,
      canUseTool,
      assistantMessage,
    )

    const raceResult = await Promise.race([toolCallPromise, abortPromise])
    cleanupAbortListener()

    if (raceResult === 'aborted' || combinedSignal.aborted) {
      return {
        behavior: 'deny',
        message: 'Permission prompt was aborted.',
        decisionReason: {
          type: 'permissionPromptTool' as const,
          permissionPromptToolName: tool.name,
          toolResult: undefined,
        },
      }
    }

    // TypeScript narrowing: after the abort check, raceResult must be ToolResult
    const result = raceResult as Awaited<typeof toolCallPromise>

    const permissionToolResultBlockParam =
      permissionPromptTool.mapToolResultToToolResultBlockParam(result.data, '1')
    if (
      !permissionToolResultBlockParam.content ||
      !Array.isArray(permissionToolResultBlockParam.content) ||
      !permissionToolResultBlockParam.content[0] ||
      permissionToolResultBlockParam.content[0].type !== 'text' ||
      typeof permissionToolResultBlockParam.content[0].text !== 'string'
    ) {
      throw new Error(
        'Permission prompt tool returned an invalid result. Expected a single text block param with type="text" and a string text value.',
      )
    }
    return permissionPromptToolResultToPermissionDecision(
      permissionToolOutputSchema().parse(
        safeParseJSON(permissionToolResultBlockParam.content[0].text),
      ),
      permissionPromptTool,
      input,
      toolUseContext,
    )
  }
  return canUseTool
}

// Exported for testing — regression: this used to crash at construction when
// getMcpTools() was empty (before per-server connects populated appState).
export function getCanUseToolFn(
  permissionPromptToolName: string | undefined,
  structuredIO: StructuredIO,
  getMcpTools: () => Tool[],
  onPermissionPrompt?: (details: RequiresActionDetails) => void,
): CanUseToolFn {
  if (permissionPromptToolName === 'stdio') {
    return structuredIO.createCanUseTool(onPermissionPrompt)
  }
  if (!permissionPromptToolName) {
    return async (
      tool,
      input,
      toolUseContext,
      assistantMessage,
      toolUseId,
      forceDecision,
    ) =>
      forceDecision ??
      (await hasPermissionsToUseTool(
        tool,
        input,
        toolUseContext,
        assistantMessage,
        toolUseId,
      ))
  }
  // Lazy lookup: MCP connects are per-server incremental in print mode, so
  // the tool may not be in appState yet at init time. Resolve on first call
  // (first permission prompt), by which point connects have had time to finish.
  let resolved: CanUseToolFn | null = null
  return async (
    tool,
    input,
    toolUseContext,
    assistantMessage,
    toolUseId,
    forceDecision,
  ) => {
    if (!resolved) {
      const mcpTools = getMcpTools()
      const permissionPromptTool = mcpTools.find(t =>
        toolMatchesName(t, permissionPromptToolName),
      ) as PermissionPromptTool | undefined
      if (!permissionPromptTool) {
        const error = `Error: MCP tool ${permissionPromptToolName} (passed via --permission-prompt-tool) not found. Available MCP tools: ${mcpTools.map(t => t.name).join(', ') || 'none'}`
        process.stderr.write(`${error}\n`)
        gracefulShutdownSync(1)
        throw new Error(error)
      }
      if (!permissionPromptTool.inputJSONSchema) {
        const error = `Error: tool ${permissionPromptToolName} (passed via --permission-prompt-tool) must be an MCP tool`
        process.stderr.write(`${error}\n`)
        gracefulShutdownSync(1)
        throw new Error(error)
      }
      resolved = createCanUseToolWithPermissionPrompt(permissionPromptTool)
    }
    return resolved(
      tool,
      input,
      toolUseContext,
      assistantMessage,
      toolUseId,
      forceDecision,
    )
  }
}

async function handleInitializeRequest(
  request: SDKControlInitializeRequest,
  requestId: string,
  initialized: boolean,
  output: Stream<StdoutMessage>,
  commands: Command[],
  modelInfos: ModelInfo[],
  structuredIO: StructuredIO,
  enableAuthStatus: boolean,
  options: {
    systemPrompt: string | undefined
    appendSystemPrompt: string | undefined
    agent?: string | undefined
    userSpecifiedModel?: string | undefined
    [key: string]: unknown
  },
  agents: AgentDefinition[],
  getAppState: () => AppState,
): Promise<void> {
  if (initialized) {
    output.enqueue({
      type: 'control_response',
      response: {
        subtype: 'error',
        error: 'Already initialized',
        request_id: requestId,
        pending_permission_requests:
          structuredIO.getPendingPermissionRequests(),
      },
    })
    return
  }

  // Apply systemPrompt/appendSystemPrompt from stdin to avoid ARG_MAX limits
  if (request.systemPrompt !== undefined) {
    options.systemPrompt = request.systemPrompt
  }
  if (request.appendSystemPrompt !== undefined) {
    options.appendSystemPrompt = request.appendSystemPrompt
  }
  if (request.promptSuggestions !== undefined) {
    options.promptSuggestions = request.promptSuggestions
  }

  // Merge agents from stdin to avoid ARG_MAX limits
  if (request.agents) {
    const stdinAgents = parseAgentsFromJson(request.agents, 'flagSettings')
    agents.push(...stdinAgents)
  }

  // Re-evaluate main thread agent after SDK agents are merged
  // This allows --agent to reference agents defined via SDK
  if (options.agent) {
    // If main.tsx already found this agent (filesystem-defined), it already
    // applied systemPrompt/model/initialPrompt. Skip to avoid double-apply.
    const alreadyResolved = getMainThreadAgentType() === options.agent
    const mainThreadAgent = agents.find(a => a.agentType === options.agent)
    if (mainThreadAgent && !alreadyResolved) {
      // Update the main thread agent type in bootstrap state
      setMainThreadAgentType(mainThreadAgent.agentType)

      // Apply the agent's system prompt if user hasn't specified a custom one
      // SDK agents are always custom agents (not built-in), so getSystemPrompt() takes no args
      if (!options.systemPrompt && !isBuiltInAgent(mainThreadAgent)) {
        const agentSystemPrompt = mainThreadAgent.getSystemPrompt()
        if (agentSystemPrompt) {
          options.systemPrompt = agentSystemPrompt
        }
      }

      // Apply the agent's model if user didn't specify one and agent has a model
      if (
        !options.userSpecifiedModel &&
        mainThreadAgent.model &&
        mainThreadAgent.model !== 'inherit'
      ) {
        const agentModel = parseUserSpecifiedModel(mainThreadAgent.model)
        setMainLoopModelOverride(agentModel)
      }

      // SDK-defined agents arrive via init, so main.tsx's lookup missed them.
      if (mainThreadAgent.initialPrompt) {
        structuredIO.prependUserMessage(mainThreadAgent.initialPrompt)
      }
    } else if (mainThreadAgent?.initialPrompt) {
      // Filesystem-defined agent (alreadyResolved by main.tsx). main.tsx
      // handles initialPrompt for the string inputPrompt case, but when
      // inputPrompt is an AsyncIterable (SDK stream-json), it can't
      // concatenate — fall back to prependUserMessage here.
      structuredIO.prependUserMessage(mainThreadAgent.initialPrompt)
    }
  }

  const settings = getSettings_DEPRECATED()
  const outputStyle = settings?.outputStyle || DEFAULT_OUTPUT_STYLE_NAME
  const availableOutputStyles = await getAllOutputStyles(getCwd())

  // Get account information
  const accountInfo = getAccountInformation()
  if (request.hooks) {
    const hooks: Partial<Record<HookEvent, HookCallbackMatcher[]>> = {}
    for (const [event, matchers] of Object.entries(request.hooks)) {
      hooks[event as HookEvent] = matchers.map(matcher => {
        const callbacks = matcher.hookCallbackIds.map(callbackId => {
          return structuredIO.createHookCallback(callbackId, matcher.timeout)
        })
        return {
          matcher: matcher.matcher,
          hooks: callbacks,
        }
      })
    }
    registerHookCallbacks(hooks)
  }
  if (request.jsonSchema) {
    setInitJsonSchema(request.jsonSchema)
  }
  const initResponse: SDKControlInitializeResponse = {
    commands: commands
      .filter(cmd => cmd.userInvocable !== false)
      .map(cmd => ({
        name: getCommandName(cmd),
        description: formatDescriptionWithSource(cmd),
        argumentHint: cmd.argumentHint || '',
      })),
    agents: agents.map(agent => ({
      name: agent.agentType,
      description: agent.whenToUse,
      // 'inherit' is an internal sentinel; normalize to undefined for the public API
      model: agent.model === 'inherit' ? undefined : agent.model,
    })),
    output_style: outputStyle,
    available_output_styles: Object.keys(availableOutputStyles),
    models: modelInfos,
    account: {
      email: accountInfo?.email,
      organization: accountInfo?.organization,
      subscriptionType: accountInfo?.subscription,
      tokenSource: accountInfo?.tokenSource,
      apiKeySource: accountInfo?.apiKeySource,
      // getAccountInformation() returns undefined under 3P providers, so the
      // other fields are all absent. apiProvider disambiguates "not logged
      // in" (firstParty + tokenSource:none) from "3P, login not applicable".
      apiProvider: getAPIProvider(),
    },
    pid: process.pid,
  }

  if (isFastModeEnabled() && isFastModeAvailable()) {
    const appState = getAppState()
    initResponse.fast_mode_state = getFastModeState(
      options.userSpecifiedModel ?? null,
      appState.fastMode,
    )
  }

  output.enqueue({
    type: 'control_response',
    response: {
      subtype: 'success',
      request_id: requestId,
      response: initResponse,
    },
  })

  // After the initialize message, check the auth status-
  // This will get notified of changes, but we also want to send the
  // initial state.
  if (enableAuthStatus) {
    const authStatusManager = AwsAuthStatusManager.getInstance()
    const status = authStatusManager.getStatus()
    if (status) {
      output.enqueue({
        type: 'auth_status',
        isAuthenticating: status.isAuthenticating,
        output: status.output,
        error: status.error,
        uuid: randomUUID(),
        session_id: getSessionId(),
      })
    }
  }
}

async function handleRewindFiles(
  userMessageId: UUID,
  appState: AppState,
  setAppState: (updater: (prev: AppState) => AppState) => void,
  dryRun: boolean,
): Promise<RewindFilesResult> {
  if (!fileHistoryEnabled()) {
    return { canRewind: false, error: 'File rewinding is not enabled.' }
  }
  if (!fileHistoryCanRestore(appState.fileHistory, userMessageId)) {
    return {
      canRewind: false,
      error: 'No file checkpoint found for this message.',
    }
  }

  if (dryRun) {
    const diffStats = await fileHistoryGetDiffStats(
      appState.fileHistory,
      userMessageId,
    )
    return {
      canRewind: true,
      filesChanged: diffStats?.filesChanged,
      insertions: diffStats?.insertions,
      deletions: diffStats?.deletions,
    }
  }

  try {
    await fileHistoryRewind(
      updater =>
        setAppState(prev => ({
          ...prev,
          fileHistory: updater(prev.fileHistory),
        })),
      userMessageId,
    )
  } catch (error) {
    return {
      canRewind: false,
      error: `Failed to rewind: ${errorMessage(error)}`,
    }
  }

  return { canRewind: true }
}

function handleSetPermissionMode(
  request: { mode: InternalPermissionMode },
  requestId: string,
  toolPermissionContext: ToolPermissionContext,
  output: Stream<StdoutMessage>,
): ToolPermissionContext {
  // Check if trying to switch to bypassPermissions mode
  if (request.mode === 'bypassPermissions') {
    if (isBypassPermissionsModeDisabled()) {
      output.enqueue({
        type: 'control_response',
        response: {
          subtype: 'error',
          request_id: requestId,
          error:
            'Cannot set permission mode to bypassPermissions because it is disabled by settings or configuration',
        },
      })
      return toolPermissionContext
    }
    if (!toolPermissionContext.isBypassPermissionsModeAvailable) {
      output.enqueue({
        type: 'control_response',
        response: {
          subtype: 'error',
          request_id: requestId,
          error:
            'Cannot set permission mode to bypassPermissions because the session was not launched with --dangerously-skip-permissions',
        },
      })
      return toolPermissionContext
    }
  }

  // Check if trying to switch to auto mode without the classifier gate
  if (
    feature('TRANSCRIPT_CLASSIFIER') &&
    request.mode === 'auto' &&
    !isAutoModeGateEnabled()
  ) {
    const reason = getAutoModeUnavailableReason()
    output.enqueue({
      type: 'control_response',
      response: {
        subtype: 'error',
        request_id: requestId,
        error: reason
          ? `Cannot set permission mode to auto: ${getAutoModeUnavailableNotification(reason)}`
          : 'Cannot set permission mode to auto',
      },
    })
    return toolPermissionContext
  }

  // Allow the mode switch
  output.enqueue({
    type: 'control_response',
    response: {
      subtype: 'success',
      request_id: requestId,
      response: {
        mode: request.mode,
      },
    },
  })

  return {
    ...transitionPermissionMode(
      toolPermissionContext.mode,
      request.mode,
      toolPermissionContext,
    ),
    mode: request.mode,
  }
}

/**
 * IDE-triggered channel enable. Derives the ChannelEntry from the connection's
 * pluginSource (IDE can't spoof kind/marketplace — we only take the server
 * name), appends it to session allowedChannels, and runs the full gate. On
 * gate failure, rolls back the append. On success, registers a notification
 * handler that enqueues channel messages at priority:'next' — drainCommandQueue
 * picks them up between turns.
 *
 * Intentionally does NOT register the claude/channel/permission handler that
 * useManageMCPConnections sets up for interactive mode. That handler resolves
 * a pending dialog inside handleInteractivePermission — but print.ts never
 * calls handleInteractivePermission. When SDK permission lands on 'ask', it
 * goes to the consumer's canUseTool callback over stdio; there is no CLI-side
 * dialog for a remote "yes tbxkq" to resolve. If an IDE wants channel-relayed
 * tool approval, that's IDE-side plumbing against its own pending-map. (Also
 * gated separately by tengu_harbor_permissions — not yet shipping on
 * interactive either.)
 */
function handleChannelEnable(
  requestId: string,
  serverName: string,
  connectionPool: readonly MCPServerConnection[],
  output: Stream<StdoutMessage>,
): void {
  const respondError = (error: string) =>
    output.enqueue({
      type: 'control_response',
      response: { subtype: 'error', request_id: requestId, error },
    })

  if (!(feature('KAIROS') || feature('KAIROS_CHANNELS'))) {
    return respondError('channels feature not available in this build')
  }

  // Only a 'connected' client has .capabilities and .client to register the
  // handler on. The pool spread at the call site matches mcp_status.
  const connection = connectionPool.find(
    c => c.name === serverName && c.type === 'connected',
  )
  if (!connection || connection.type !== 'connected') {
    return respondError(`server ${serverName} is not connected`)
  }

  const pluginSource = connection.config.pluginSource
  const parsed = pluginSource ? parsePluginIdentifier(pluginSource) : undefined
  if (!parsed?.marketplace) {
    // No pluginSource or @-less source — can never pass the {plugin,
    // marketplace}-keyed allowlist. Short-circuit with the same reason the
    // gate would produce.
    return respondError(
      `server ${serverName} is not plugin-sourced; channel_enable requires a marketplace plugin`,
    )
  }

  const entry: ChannelEntry = {
    kind: 'plugin',
    name: parsed.name,
    marketplace: parsed.marketplace,
  }
  // Idempotency: don't double-append on repeat enable.
  const prior = getAllowedChannels()
  const already = prior.some(
    e =>
      e.kind === 'plugin' &&
      e.name === entry.name &&
      e.marketplace === entry.marketplace,
  )
  if (!already) setAllowedChannels([...prior, entry])

  const gate = gateChannelServer(
    serverName,
    connection.capabilities,
    pluginSource,
  )
  if (gate.action === 'skip') {
    // Rollback — only remove the entry we appended.
    if (!already) setAllowedChannels(prior)
    return respondError(gate.reason)
  }

  const pluginId =
    `${entry.name}@${entry.marketplace}` as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS
  logMCPDebug(serverName, 'Channel notifications registered')
  logEvent('tengu_mcp_channel_enable', { plugin: pluginId })

  // Identical enqueue shape to the interactive register block in
  // useManageMCPConnections. drainCommandQueue processes it between turns —
  // channel messages queue at priority 'next' and are seen by the model on
  // the turn after they arrive.
  connection.client.setNotificationHandler(
    ChannelMessageNotificationSchema(),
    async notification => {
      const { content, meta } = notification.params
      logMCPDebug(
        serverName,
        `notifications/claude/channel: ${content.slice(0, 80)}`,
      )
      logEvent('tengu_mcp_channel_message', {
        content_length: content.length,
        meta_key_count: Object.keys(meta ?? {}).length,
        entry_kind:
          'plugin' as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
        is_dev: false,
        plugin: pluginId,
      })
      enqueue({
        mode: 'prompt',
        value: wrapChannelMessage(serverName, content, meta),
        priority: 'next',
        isMeta: true,
        origin: { kind: 'channel', server: serverName },
        skipSlashCommands: true,
      })
    },
  )

  output.enqueue({
    type: 'control_response',
    response: {
      subtype: 'success',
      request_id: requestId,
      response: undefined,
    },
  })
}

/**
 * Re-register the channel notification handler after mcp_reconnect /
 * mcp_toggle creates a new client. handleChannelEnable bound the handler to
 * the OLD client object; allowedChannels survives the reconnect but the
 * handler binding does not. Without this, channel messages silently drop
 * after a reconnect while the IDE still believes the channel is live.
 *
 * Mirrors the interactive CLI's onConnectionAttempt in
 * useManageMCPConnections, which re-gates on every new connection. Paired
 * with registerElicitationHandlers at the same call sites.
 *
 * No-op if the server was never channel-enabled: gateChannelServer calls
 * findChannelEntry internally and returns skip/session for an unlisted
 * server, so reconnecting a non-channel MCP server costs one feature-flag
 * check.
 */
function reregisterChannelHandlerAfterReconnect(
  connection: MCPServerConnection,
): void {
  if (!(feature('KAIROS') || feature('KAIROS_CHANNELS'))) return
  if (connection.type !== 'connected') return

  const gate = gateChannelServer(
    connection.name,
    connection.capabilities,
    connection.config.pluginSource,
  )
  if (gate.action !== 'register') return

  const entry = findChannelEntry(connection.name, getAllowedChannels())
  const pluginId =
    entry?.kind === 'plugin'
      ? (`${entry.name}@${entry.marketplace}` as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS)
      : undefined

  logMCPDebug(
    connection.name,
    'Channel notifications re-registered after reconnect',
  )
  connection.client.setNotificationHandler(
    ChannelMessageNotificationSchema(),
    async notification => {
      const { content, meta } = notification.params
      logMCPDebug(
        connection.name,
        `notifications/claude/channel: ${content.slice(0, 80)}`,
      )
      logEvent('tengu_mcp_channel_message', {
        content_length: content.length,
        meta_key_count: Object.keys(meta ?? {}).length,
        entry_kind:
          entry?.kind as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
        is_dev: entry?.dev ?? false,
        plugin: pluginId,
      })
      enqueue({
        mode: 'prompt',
        value: wrapChannelMessage(connection.name, content, meta),
        priority: 'next',
        isMeta: true,
        origin: { kind: 'channel', server: connection.name },
        skipSlashCommands: true,
      })
    },
  )
}

/**
 * Emits an error message in the correct format based on outputFormat.
 * When using stream-json, writes JSON to stdout; otherwise writes plain text to stderr.
 */
function emitLoadError(
  message: string,
  outputFormat: string | undefined,
): void {
  if (outputFormat === 'stream-json') {
    const errorResult = {
      type: 'result',
      subtype: 'error_during_execution',
      duration_ms: 0,
      duration_api_ms: 0,
      is_error: true,
      num_turns: 0,
      stop_reason: null,
      session_id: getSessionId(),
      total_cost_usd: 0,
      usage: EMPTY_USAGE,
      modelUsage: {},
      permission_denials: [],
      uuid: randomUUID(),
      errors: [message],
    }
    process.stdout.write(jsonStringify(errorResult) + '\n')
  } else {
    process.stderr.write(message + '\n')
  }
}

/**
 * Removes an interrupted user message and its synthetic assistant sentinel
 * from the message array. Used during gateway-triggered restarts to clean up
 * the message history before re-enqueuing the interrupted prompt.
 *
 * @internal Exported for testing
 */
export function removeInterruptedMessage(
  messages: Message[],
  interruptedUserMessage: NormalizedUserMessage,
): void {
  const idx = messages.findIndex(m => m.uuid === interruptedUserMessage.uuid)
  if (idx !== -1) {
    // Remove the user message and the sentinel that immediately follows it.
    // splice safely handles the case where idx is the last element.
    messages.splice(idx, 2)
  }
}

type LoadInitialMessagesResult = {
  messages: Message[]
  turnInterruptionState?: TurnInterruptionState
  agentSetting?: string
}

async function loadInitialMessages(
  setAppState: (f: (prev: AppState) => AppState) => void,
  options: {
    continue: boolean | undefined
    teleport: string | true | null | undefined
    resume: string | boolean | undefined
    resumeSessionAt: string | undefined
    forkSession: boolean | undefined
    outputFormat: string | undefined
    sessionStartHooksPromise?: ReturnType<typeof processSessionStartHooks>
    restoredWorkerState: Promise<SessionExternalMetadata | null>
  },
): Promise<LoadInitialMessagesResult> {
  const persistSession = !isSessionPersistenceDisabled()
  // Handle continue in print mode
  if (options.continue) {
    try {
      logEvent('tengu_continue_print', {})

      const result = await loadConversationForResume(
        undefined /* sessionId */,
        undefined /* file path */,
      )
      if (result) {
        // Match coordinator mode to the resumed session's mode
        if (feature('COORDINATOR_MODE') && coordinatorModeModule) {
          const warning = coordinatorModeModule.matchSessionMode(result.mode)
          if (warning) {
            process.stderr.write(warning + '\n')
            // Refresh agent definitions to reflect the mode switch
            const {
              getAgentDefinitionsWithOverrides,
              getActiveAgentsFromList,
            } =
              // eslint-disable-next-line @typescript-eslint/no-require-imports
              require('../tools/AgentTool/loadAgentsDir.js') as typeof import('../tools/AgentTool/loadAgentsDir.js')
            getAgentDefinitionsWithOverrides.cache.clear?.()
            const freshAgentDefs = await getAgentDefinitionsWithOverrides(
              getCwd(),
            )

            setAppState(prev => ({
              ...prev,
              agentDefinitions: {
                ...freshAgentDefs,
                allAgents: freshAgentDefs.allAgents,
                activeAgents: getActiveAgentsFromList(freshAgentDefs.allAgents),
              },
            }))
          }
        }

        // Reuse the resumed session's ID
        if (!options.forkSession) {
          if (result.sessionId) {
            switchSession(
              asSessionId(result.sessionId),
              result.fullPath ? dirname(result.fullPath) : null,
            )
            if (persistSession) {
              await resetSessionFilePointer()
            }
          }
        }
        restoreSessionStateFromLog(result, setAppState)

        // Restore session metadata so it's re-appended on exit via reAppendSessionMetadata
        restoreSessionMetadata(
          options.forkSession
            ? { ...result, worktreeSession: undefined }
            : result,
        )

        // Write mode entry for the resumed session
        if (feature('COORDINATOR_MODE') && coordinatorModeModule) {
          saveMode(
            coordinatorModeModule.isCoordinatorMode()
              ? 'coordinator'
              : 'normal',
          )
        }

        return {
          messages: result.messages,
          turnInterruptionState: result.turnInterruptionState,
          agentSetting: result.agentSetting,
        }
      }
    } catch (error) {
      logError(error)
      gracefulShutdownSync(1)
      return { messages: [] }
    }
  }

  // Handle teleport in print mode
  if (options.teleport) {
    try {
      if (!isPolicyAllowed('allow_remote_sessions')) {
        throw new Error(
          "Remote sessions are disabled by your organization's policy.",
        )
      }

      logEvent('tengu_teleport_print', {})

      if (typeof options.teleport !== 'string') {
        throw new Error('No session ID provided for teleport')
      }

      const {
        checkOutTeleportedSessionBranch,
        processMessagesForTeleportResume,
        teleportResumeCodeSession,
        validateGitState,
      } = await import('src/utils/teleport.js')
      await validateGitState()
      const teleportResult = await teleportResumeCodeSession(options.teleport)
      const { branchError } = await checkOutTeleportedSessionBranch(
        teleportResult.branch,
      )
      return {
        messages: processMessagesForTeleportResume(
          teleportResult.log,
          branchError,
        ),
      }
    } catch (error) {
      logError(error)
      gracefulShutdownSync(1)
      return { messages: [] }
    }
  }

  // Handle resume in print mode (accepts session ID or URL)
  // URLs are [ANT-ONLY]
  if (options.resume) {
    try {
      logEvent('tengu_resume_print', {})

      // In print mode - we require a valid session ID, JSONL file or URL
      const parsedSessionId = parseSessionIdentifier(
        typeof options.resume === 'string' ? options.resume : '',
      )
      if (!parsedSessionId) {
        let errorMessage =
          'Error: --resume requires a valid session ID when used with --print. Usage: claude -p --resume <session-id>'
        if (typeof options.resume === 'string') {
          errorMessage += `. Session IDs must be in UUID format (e.g., 550e8400-e29b-41d4-a716-446655440000). Provided value "${options.resume}" is not a valid UUID`
        }
        emitLoadError(errorMessage, options.outputFormat)
        gracefulShutdownSync(1)
        return { messages: [] }
      }

      // Hydrate local transcript from remote before loading
      if (isEnvTruthy(process.env.CLAUDE_CODE_USE_CCR_V2)) {
        // Await restore alongside hydration so SSE catchup lands on
        // restored state, not a fresh default.
        const [, metadata] = await Promise.all([
          hydrateFromCCRv2InternalEvents(parsedSessionId.sessionId),
          options.restoredWorkerState,
        ])
        if (metadata) {
          setAppState(externalMetadataToAppState(metadata))
          if (typeof metadata.model === 'string') {
            setMainLoopModelOverride(metadata.model)
          }
        }
      } else if (
        parsedSessionId.isUrl &&
        parsedSessionId.ingressUrl &&
        isEnvTruthy(process.env.ENABLE_SESSION_PERSISTENCE)
      ) {
        // v1: fetch session logs from Session Ingress
        await hydrateRemoteSession(
          parsedSessionId.sessionId,
          parsedSessionId.ingressUrl,
        )
      }

      // Load the conversation with the specified session ID
      const result = await loadConversationForResume(
        parsedSessionId.sessionId,
        parsedSessionId.jsonlFile || undefined,
      )

      // hydrateFromCCRv2InternalEvents writes an empty transcript file for
      // fresh sessions (writeFile(sessionFile, '') with zero events), so
      // loadConversationForResume returns {messages: []} not null. Treat
      // empty the same as null so SessionStart still fires.
      if (!result || result.messages.length === 0) {
        // For URL-based or CCR v2 resume, start with empty session (it was hydrated but empty)
        if (
          parsedSessionId.isUrl ||
          isEnvTruthy(process.env.CLAUDE_CODE_USE_CCR_V2)
        ) {
          // Execute SessionStart hooks for startup since we're starting a new session
          return {
            messages: await (options.sessionStartHooksPromise ??
              processSessionStartHooks('startup')),
          }
        } else {
          emitLoadError(
            `No conversation found with session ID: ${parsedSessionId.sessionId}`,
            options.outputFormat,
          )
          gracefulShutdownSync(1)
          return { messages: [] }
        }
      }

      // Handle resumeSessionAt feature
      if (options.resumeSessionAt) {
        const index = result.messages.findIndex(
          m => m.uuid === options.resumeSessionAt,
        )
        if (index < 0) {
          emitLoadError(
            `No message found with message.uuid of: ${options.resumeSessionAt}`,
            options.outputFormat,
          )
          gracefulShutdownSync(1)
          return { messages: [] }
        }

        result.messages = index >= 0 ? result.messages.slice(0, index + 1) : []
      }

      // Match coordinator mode to the resumed session's mode
      if (feature('COORDINATOR_MODE') && coordinatorModeModule) {
        const warning = coordinatorModeModule.matchSessionMode(result.mode)
        if (warning) {
          process.stderr.write(warning + '\n')
          // Refresh agent definitions to reflect the mode switch
          const { getAgentDefinitionsWithOverrides, getActiveAgentsFromList } =
            // eslint-disable-next-line @typescript-eslint/no-require-imports
            require('../tools/AgentTool/loadAgentsDir.js') as typeof import('../tools/AgentTool/loadAgentsDir.js')
          getAgentDefinitionsWithOverrides.cache.clear?.()
          const freshAgentDefs = await getAgentDefinitionsWithOverrides(
            getCwd(),
          )

          setAppState(prev => ({
            ...prev,
            agentDefinitions: {
              ...freshAgentDefs,
              allAgents: freshAgentDefs.allAgents,
              activeAgents: getActiveAgentsFromList(freshAgentDefs.allAgents),
            },
          }))
        }
      }

      // Reuse the resumed session's ID
      if (!options.forkSession && result.sessionId) {
        switchSession(
          asSessionId(result.sessionId),
          result.fullPath ? dirname(result.fullPath) : null,
        )
        if (persistSession) {
          await resetSessionFilePointer()
        }
      }
      restoreSessionStateFromLog(result, setAppState)

      // Restore session metadata so it's re-appended on exit via reAppendSessionMetadata
      restoreSessionMetadata(
        options.forkSession
          ? { ...result, worktreeSession: undefined }
          : result,
      )

      // Write mode entry for the resumed session
      if (feature('COORDINATOR_MODE') && coordinatorModeModule) {
        saveMode(
          coordinatorModeModule.isCoordinatorMode() ? 'coordinator' : 'normal',
        )
      }

      return {
        messages: result.messages,
        turnInterruptionState: result.turnInterruptionState,
        agentSetting: result.agentSetting,
      }
    } catch (error) {
      logError(error)
      const errorMessage =
        error instanceof Error
          ? `Failed to resume session: ${error.message}`
          : 'Failed to resume session with --print mode'
      emitLoadError(errorMessage, options.outputFormat)
      gracefulShutdownSync(1)
      return { messages: [] }
    }
  }

  // Join the SessionStart hooks promise kicked in main.tsx (or run fresh if
  // it wasn't kicked — e.g. --continue with no prior session falls through
  // here with sessionStartHooksPromise undefined because main.tsx guards on continue)
  return {
    messages: await (options.sessionStartHooksPromise ??
      processSessionStartHooks('startup')),
  }
}

function getStructuredIO(
  inputPrompt: string | AsyncIterable<string>,
  options: {
    sdkUrl: string | undefined
    replayUserMessages?: boolean
  },
): StructuredIO {
  let inputStream: AsyncIterable<string>
  if (typeof inputPrompt === 'string') {
    if (inputPrompt.trim() !== '') {
      // Normalize to a streaming input.
      inputStream = fromArray([
        jsonStringify({
          type: 'user',
          session_id: '',
          message: {
            role: 'user',
            content: inputPrompt,
          },
          parent_tool_use_id: null,
        } satisfies SDKUserMessage),
      ])
    } else {
      // Empty string - create empty stream
      inputStream = fromArray([])
    }
  } else {
    inputStream = inputPrompt
  }

  // Use RemoteIO if sdkUrl is provided, otherwise use regular StructuredIO
  return options.sdkUrl
    ? new RemoteIO(options.sdkUrl, inputStream, options.replayUserMessages)
    : new StructuredIO(inputStream, options.replayUserMessages)
}

/**
 * Handles unexpected permission responses by looking up the unresolved tool
 * call in the transcript and enqueuing it for execution.
 *
 * Returns true if a permission was enqueued, false otherwise.
 */
export async function handleOrphanedPermissionResponse({
  message,
  setAppState,
  onEnqueued,
  handledToolUseIds,
}: {
  message: SDKControlResponse
  setAppState: (f: (prev: AppState) => AppState) => void
  onEnqueued?: () => void
  handledToolUseIds: Set<string>
}): Promise<boolean> {
  if (
    message.response.subtype === 'success' &&
    message.response.response?.toolUseID &&
    typeof message.response.response.toolUseID === 'string'
  ) {
    const permissionResult = message.response.response as PermissionResult
    const { toolUseID } = permissionResult
    if (!toolUseID) {
      return false
    }

    logForDebugging(
      `handleOrphanedPermissionResponse: received orphaned control_response for toolUseID=${toolUseID} request_id=${message.response.request_id}`,
    )

    // Prevent re-processing the same orphaned tool_use. Without this guard,
    // duplicate control_response deliveries (e.g. from WebSocket reconnect)
    // cause the same tool to be executed multiple times, producing duplicate
    // tool_use IDs in the messages array and a 400 error from the API.
    // Once corrupted, every retry accumulates more duplicates.
    if (handledToolUseIds.has(toolUseID)) {
      logForDebugging(
        `handleOrphanedPermissionResponse: skipping duplicate orphaned permission for toolUseID=${toolUseID} (already handled)`,
      )
      return false
    }

    const assistantMessage = await findUnresolvedToolUse(toolUseID)
    if (!assistantMessage) {
      logForDebugging(
        `handleOrphanedPermissionResponse: no unresolved tool_use found for toolUseID=${toolUseID} (already resolved in transcript)`,
      )
      return false
    }

    handledToolUseIds.add(toolUseID)
    logForDebugging(
      `handleOrphanedPermissionResponse: enqueuing orphaned permission for toolUseID=${toolUseID} messageID=${assistantMessage.message.id}`,
    )
    enqueue({
      mode: 'orphaned-permission' as const,
      value: [],
      orphanedPermission: {
        permissionResult,
        assistantMessage,
      },
    })

    onEnqueued?.()
    return true
  }
  return false
}

export type DynamicMcpState = {
  clients: MCPServerConnection[]
  tools: Tools
  configs: Record<string, ScopedMcpServerConfig>
}

/**
 * Converts a process transport config to a scoped config.
 * The types are structurally compatible, so we just add the scope.
 */
function toScopedConfig(
  config: McpServerConfigForProcessTransport,
): ScopedMcpServerConfig {
  // McpServerConfigForProcessTransport is a subset of McpServerConfig
  // (it excludes IDE-specific types like sse-ide and ws-ide)
  // Adding scope makes it a valid ScopedMcpServerConfig
  return { ...config, scope: 'dynamic' } as ScopedMcpServerConfig
}

/**
 * State for SDK MCP servers that run in the SDK process.
 */
export type SdkMcpState = {
  configs: Record<string, McpSdkServerConfig>
  clients: MCPServerConnection[]
  tools: Tools
}

/**
 * Result of handleMcpSetServers - contains new state and response data.
 */
export type McpSetServersResult = {
  response: SDKControlMcpSetServersResponse
  newSdkState: SdkMcpState
  newDynamicState: DynamicMcpState
  sdkServersChanged: boolean
}

/**
 * Handles mcp_set_servers requests by processing both SDK and process-based servers.
 * SDK servers run in the SDK process; process-based servers are spawned by the CLI.
 *
 * Applies enterprise allowedMcpServers/deniedMcpServers policy — same filter as
 * --mcp-config (see filterMcpServersByPolicy call in main.tsx). Without this,
 * SDK V2 Query.setMcpServers() was a second policy bypass vector. Blocked servers
 * are reported in response.errors so the SDK consumer knows why they weren't added.
 */
export async function handleMcpSetServers(
  servers: Record<string, McpServerConfigForProcessTransport>,
  sdkState: SdkMcpState,
  dynamicState: DynamicMcpState,
  setAppState: (f: (prev: AppState) => AppState) => void,
): Promise<McpSetServersResult> {
  // Enforce enterprise MCP policy on process-based servers (stdio/http/sse).
  // Mirrors the --mcp-config filter in main.tsx — both user-controlled injection
  // paths must have the same gate. type:'sdk' servers are exempt (SDK-managed,
  // CLI never spawns/connects for them — see filterMcpServersByPolicy jsdoc).
  // Blocked servers go into response.errors so the SDK caller sees why.
  const { allowed: allowedServers, blocked } = filterMcpServersByPolicy(servers)
  const policyErrors: Record<string, string> = {}
  for (const name of blocked) {
    policyErrors[name] =
      'Blocked by enterprise policy (allowedMcpServers/deniedMcpServers)'
  }

  // Separate SDK servers from process-based servers
  const sdkServers: Record<string, McpSdkServerConfig> = {}
  const processServers: Record<string, McpServerConfigForProcessTransport> = {}

  for (const [name, config] of Object.entries(allowedServers)) {
    if (config.type === 'sdk') {
      sdkServers[name] = config
    } else {
      processServers[name] = config
    }
  }

  // Handle SDK servers
  const currentSdkNames = new Set(Object.keys(sdkState.configs))
  const newSdkNames = new Set(Object.keys(sdkServers))
  const sdkAdded: string[] = []
  const sdkRemoved: string[] = []

  const newSdkConfigs = { ...sdkState.configs }
  let newSdkClients = [...sdkState.clients]
  let newSdkTools = [...sdkState.tools]

  // Remove SDK servers no longer in desired state
  for (const name of currentSdkNames) {
    if (!newSdkNames.has(name)) {
      const client = newSdkClients.find(c => c.name === name)
      if (client && client.type === 'connected') {
        await client.cleanup()
      }
      newSdkClients = newSdkClients.filter(c => c.name !== name)
      const prefix = `mcp__${name}__`
      newSdkTools = newSdkTools.filter(t => !t.name.startsWith(prefix))
      delete newSdkConfigs[name]
      sdkRemoved.push(name)
    }
  }

  // Add new SDK servers as pending - they'll be upgraded to connected
  // when updateSdkMcp() runs on the next query
  for (const [name, config] of Object.entries(sdkServers)) {
    if (!currentSdkNames.has(name)) {
      newSdkConfigs[name] = config
      const pendingClient: MCPServerConnection = {
        type: 'pending',
        name,
        config: { ...config, scope: 'dynamic' as const },
      }
      newSdkClients = [...newSdkClients, pendingClient]
      sdkAdded.push(name)
    }
  }

  // Handle process-based servers
  const processResult = await reconcileMcpServers(
    processServers,
    dynamicState,
    setAppState,
  )

  return {
    response: {
      added: [...sdkAdded, ...processResult.response.added],
      removed: [...sdkRemoved, ...processResult.response.removed],
      errors: { ...policyErrors, ...processResult.response.errors },
    },
    newSdkState: {
      configs: newSdkConfigs,
      clients: newSdkClients,
      tools: newSdkTools,
    },
    newDynamicState: processResult.newState,
    sdkServersChanged: sdkAdded.length > 0 || sdkRemoved.length > 0,
  }
}

/**
 * Reconciles the current set of dynamic MCP servers with a new desired state.
 * Handles additions, removals, and config changes.
 */
export async function reconcileMcpServers(
  desiredConfigs: Record<string, McpServerConfigForProcessTransport>,
  currentState: DynamicMcpState,
  setAppState: (f: (prev: AppState) => AppState) => void,
): Promise<{
  response: SDKControlMcpSetServersResponse
  newState: DynamicMcpState
}> {
  const currentNames = new Set(Object.keys(currentState.configs))
  const desiredNames = new Set(Object.keys(desiredConfigs))

  const toRemove = [...currentNames].filter(n => !desiredNames.has(n))
  const toAdd = [...desiredNames].filter(n => !currentNames.has(n))

  // Check for config changes (same name, different config)
  const toCheck = [...currentNames].filter(n => desiredNames.has(n))
  const toReplace = toCheck.filter(name => {
    const currentConfig = currentState.configs[name]
    const desiredConfigRaw = desiredConfigs[name]
    if (!currentConfig || !desiredConfigRaw) return true
    const desiredConfig = toScopedConfig(desiredConfigRaw)
    return !areMcpConfigsEqual(currentConfig, desiredConfig)
  })

  const removed: string[] = []
  const added: string[] = []
  const errors: Record<string, string> = {}

  let newClients = [...currentState.clients]
  let newTools = [...currentState.tools]

  // Remove old servers (including ones being replaced)
  for (const name of [...toRemove, ...toReplace]) {
    const client = newClients.find(c => c.name === name)
    const config = currentState.configs[name]
    if (client && config) {
      if (client.type === 'connected') {
        try {
          await client.cleanup()
        } catch (e) {
          logError(e)
        }
      }
      // Clear the memoization cache
      await clearServerCache(name, config)
    }

    // Remove tools from this server
    const prefix = `mcp__${name}__`
    newTools = newTools.filter(t => !t.name.startsWith(prefix))

    // Remove from clients list
    newClients = newClients.filter(c => c.name !== name)

    // Track removal (only for actually removed, not replaced)
    if (toRemove.includes(name)) {
      removed.push(name)
    }
  }

  // Add new servers (including replacements)
  for (const name of [...toAdd, ...toReplace]) {
    const config = desiredConfigs[name]
    if (!config) continue
    const scopedConfig = toScopedConfig(config)

    // SDK servers are managed by the SDK process, not the CLI.
    // Just track them without trying to connect.
    if (config.type === 'sdk') {
      added.push(name)
      continue
    }

    try {
      const client = await connectToServer(name, scopedConfig)
      newClients.push(client)

      if (client.type === 'connected') {
        const serverTools = await fetchToolsForClient(client)
        newTools.push(...serverTools)
      } else if (client.type === 'failed') {
        errors[name] = client.error || 'Connection failed'
      }

      added.push(name)
    } catch (e) {
      const err = toError(e)
      errors[name] = err.message
      logError(err)
    }
  }

  // Build new configs
  const newConfigs: Record<string, ScopedMcpServerConfig> = {}
  for (const name of desiredNames) {
    const config = desiredConfigs[name]
    if (config) {
      newConfigs[name] = toScopedConfig(config)
    }
  }

  const newState: DynamicMcpState = {
    clients: newClients,
    tools: newTools,
    configs: newConfigs,
  }

  // Update AppState with the new tools
  setAppState(prev => {
    // Get all dynamic server names (current + new)
    const allDynamicServerNames = new Set([
      ...Object.keys(currentState.configs),
      ...Object.keys(newConfigs),
    ])

    // Remove old dynamic tools
    const nonDynamicTools = prev.mcp.tools.filter(t => {
      for (const serverName of allDynamicServerNames) {
        if (t.name.startsWith(`mcp__${serverName}__`)) {
          return false
        }
      }
      return true
    })

    // Remove old dynamic clients
    const nonDynamicClients = prev.mcp.clients.filter(c => {
      return !allDynamicServerNames.has(c.name)
    })

    return {
      ...prev,
      mcp: {
        ...prev.mcp,
        tools: [...nonDynamicTools, ...newTools],
        clients: [...nonDynamicClients, ...newClients],
      },
    }
  })

  return {
    response: { added, removed, errors },
    newState,
  }
}