diff --git a/apps/kimi-code/src/cli/commands.ts b/apps/kimi-code/src/cli/commands.ts
index 32a65eb0e..e715b96b7 100644
--- a/apps/kimi-code/src/cli/commands.ts
+++ b/apps/kimi-code/src/cli/commands.ts
@@ -66,6 +66,24 @@ export function createProgram(
         'Output format for prompt mode. Defaults to text.',
       ).choices(['text', 'stream-json']),
     )
+    .addOption(
+      new Option(
+        '--input-format <format>',
+        'Read prompts from stdin in this format instead of --prompt. `stream-json` reads one JSON user message per line (multi-turn); `text` reads all of stdin as a single prompt. Implies prompt mode.',
+      ).choices(['text', 'stream-json']),
+    )
+    .addOption(
+      new Option(
+        '--final-message-only',
+        'In prompt mode, emit only the final assistant message of each turn.',
+      ).default(false),
+    )
+    .addOption(
+      new Option(
+        '--quiet',
+        'Shorthand for prompt mode with --output-format text --final-message-only.',
+      ).default(false),
+    )
     .addOption(
       new Option(
         '--skills-dir <dir>',
@@ -131,6 +149,9 @@ export function createProgram(
       plan: raw['plan'] as boolean,
       model: raw['model'] as string | undefined,
       outputFormat: raw['outputFormat'] as CLIOptions['outputFormat'],
+      inputFormat: raw['inputFormat'] as CLIOptions['inputFormat'],
+      finalMessageOnly: raw['finalMessageOnly'] === true,
+      quiet: raw['quiet'] === true,
       prompt: raw['prompt'] as string | undefined,
       skillsDirs: raw['skillsDir'] as string[],
       addDirs: raw['addDir'] as string[],
diff --git a/apps/kimi-code/src/cli/options.ts b/apps/kimi-code/src/cli/options.ts
index 2e0c33a42..89822ce45 100644
--- a/apps/kimi-code/src/cli/options.ts
+++ b/apps/kimi-code/src/cli/options.ts
@@ -1,5 +1,6 @@
 export type UIMode = 'shell' | 'print';
 export type PromptOutputFormat = 'text' | 'stream-json';
+export type PromptInputFormat = 'text' | 'stream-json';
 
 export interface CLIOptions {
   session: string | undefined;
@@ -9,6 +10,9 @@ export interface CLIOptions {
   plan: boolean;
   model: string | undefined;
   outputFormat: PromptOutputFormat | undefined;
+  inputFormat?: PromptInputFormat | undefined;
+  finalMessageOnly?: boolean;
+  quiet?: boolean;
   prompt: string | undefined;
   skillsDirs: string[];
   addDirs?: string[];
@@ -28,8 +32,11 @@ export class OptionConflictError extends Error {
 
 export function validateOptions(opts: CLIOptions): ValidatedOptions {
   const prompt = opts.prompt;
-  const promptMode = prompt !== undefined;
-  if (promptMode && prompt.trim().length === 0) {
+  const hasPrompt = prompt !== undefined;
+  // Prompt mode is entered by `--prompt`, by `--input-format` (the prompt is
+  // then read from stdin instead of the flag), or by `--quiet`.
+  const promptMode = hasPrompt || opts.inputFormat !== undefined || opts.quiet === true;
+  if (hasPrompt && prompt.trim().length === 0) {
     throw new OptionConflictError('Prompt cannot be empty.');
   }
   if (opts.model !== undefined && opts.model.trim().length === 0) {
@@ -38,6 +45,19 @@ export function validateOptions(opts: CLIOptions): ValidatedOptions {
   if (!promptMode && opts.outputFormat !== undefined) {
     throw new OptionConflictError('Output format is only supported in prompt mode.');
   }
+  if (!promptMode && opts.finalMessageOnly) {
+    throw new OptionConflictError('Final-message-only output is only supported in prompt mode.');
+  }
+  // `--quiet` is shorthand for `--output-format text --final-message-only`, so a
+  // conflicting explicit output format is rejected.
+  if (opts.quiet === true && opts.outputFormat !== undefined && opts.outputFormat !== 'text') {
+    throw new OptionConflictError('Quiet mode implies --output-format text.');
+  }
+  if (hasPrompt && opts.inputFormat !== undefined) {
+    throw new OptionConflictError(
+      'Cannot combine --prompt with --input-format; the prompt is read from stdin.',
+    );
+  }
   if (promptMode && opts.yolo) {
     throw new OptionConflictError('Cannot combine --prompt with --yolo.');
   }
diff --git a/apps/kimi-code/src/cli/run-prompt.ts b/apps/kimi-code/src/cli/run-prompt.ts
index 79a301ba1..b3f8c14d5 100644
--- a/apps/kimi-code/src/cli/run-prompt.ts
+++ b/apps/kimi-code/src/cli/run-prompt.ts
@@ -18,6 +18,7 @@ import {
   type TelemetryClient,
 } from '@moonshot-ai/kimi-code-sdk';
 import { resolve } from 'pathe';
+import { createInterface } from 'node:readline';
 
 import { CLI_SHUTDOWN_TIMEOUT_MS } from '#/constant/app';
 
@@ -40,9 +41,18 @@ interface PromptOutput {
 interface PromptRunIO {
   readonly stdout?: PromptOutput;
   readonly stderr?: PromptOutput;
+  /** Source of stdin lines for `--input-format`. Defaults to a reader over `process.stdin`. */
+  readonly stdin?: AsyncIterable<string>;
+  /** Injectable clock for the background-task drain loop (tests). */
+  readonly clock?: PromptClock;
   readonly process?: PromptProcess;
 }
 
+interface PromptClock {
+  now(): number;
+  sleep(ms: number): Promise<void>;
+}
+
 interface PromptProcess {
   once(signal: NodeJS.Signals, listener: () => Promise<void>): unknown;
   off(signal: NodeJS.Signals, listener: () => Promise<void>): unknown;
@@ -53,6 +63,34 @@ const PROMPT_UI_MODE = 'print';
 const PROMPT_MAIN_AGENT_ID = 'main';
 const PROMPT_BLOCK_BULLET = '• ';
 const PROMPT_BLOCK_INDENT = '  ';
+/** Generic non-retryable failure. */
+const CLI_EXIT_FAILURE = 1;
+/** Transient provider failure (connection/timeout/rate-limit/5xx) — safe to retry. Mirrors EX_TEMPFAIL. */
+const CLI_EXIT_RETRYABLE = 75;
+
+/** Env override for keeping background tasks alive past exit (matches the session resolver). */
+const BACKGROUND_KEEP_ALIVE_ON_EXIT_ENV = 'KIMI_CODE_BACKGROUND_KEEP_ALIVE_ON_EXIT';
+/** Default ceiling (seconds) for waiting on background tasks at exit when none is configured. */
+const DEFAULT_PRINT_WAIT_CEILING_S = 3600;
+/** Poll interval (ms) while draining background tasks at exit. */
+const BACKGROUND_DRAIN_POLL_MS = 500;
+
+/**
+ * A turn-level failure (provider/turn error). Carries the structured code and
+ * retryable flag so the prompt runner can emit a machine-readable error and pick
+ * an exit code. Setup errors (no model, session not found, …) are plain Errors
+ * and are not caught by the turn handler.
+ */
+class PromptTurnError extends Error {
+  constructor(
+    readonly code: string,
+    readonly detail: string,
+    readonly retryable: boolean,
+  ) {
+    super(`${code}: ${detail}`);
+    this.name = 'PromptTurnError';
+  }
+}
 
 export async function runPrompt(
   opts: CLIOptions,
@@ -139,18 +177,74 @@ export async function runPrompt(
     });
     setCrashPhase('runtime');
 
-    const outputFormat = opts.outputFormat ?? 'text';
-    // Headless goal mode: `kimi -p "/goal <objective>"`. The goal driver keeps
-    // the turn-run alive across continuation turns, so the normal prompt-turn
-    // waiter blocks until the goal is terminal; we then emit a summary and set a
-    // distinct exit code.
-    const goalCreate = parseHeadlessGoalCreate(opts.prompt!);
-    if (goalCreate !== undefined) {
-      await runHeadlessGoal(session, goalCreate, goalModel, outputFormat, stdout, stderr);
-    } else {
-      await runPromptTurn(session, opts.prompt!, outputFormat, stdout, stderr);
+    // `--quiet` is shorthand for `--output-format text --final-message-only`.
+    const finalOnly = (opts.finalMessageOnly ?? false) || opts.quiet === true;
+    const outputFormat: PromptOutputFormat =
+      opts.quiet === true ? 'text' : (opts.outputFormat ?? 'text');
+    const inputFormat = opts.inputFormat;
+    try {
+      if (inputFormat !== undefined) {
+        // Prompts come from stdin instead of `--prompt`. `stream-json` reads one
+        // JSON user message per line and runs a turn for each (multi-turn);
+        // `text` reads all of stdin as a single prompt.
+        const lines = io.stdin ?? defaultStdinLines(process.stdin);
+        if (inputFormat === 'stream-json') {
+          for await (const command of readUserCommands(lines, stderr)) {
+            await runPromptTurn(session, command, outputFormat, finalOnly, stdout, stderr);
+          }
+        } else {
+          const command = (await collectLines(lines)).trim();
+          if (command.length > 0) {
+            await runPromptTurn(session, command, outputFormat, finalOnly, stdout, stderr);
+          }
+        }
+      } else {
+        // Headless goal mode: `kimi -p "/goal <objective>"`. The goal driver
+        // keeps the turn-run alive across continuation turns, so the normal
+        // prompt-turn waiter blocks until the goal is terminal; we then emit a
+        // summary and set a distinct exit code.
+        const goalCreate = parseHeadlessGoalCreate(opts.prompt!);
+        if (goalCreate !== undefined) {
+          await runHeadlessGoal(
+            session,
+            goalCreate,
+            goalModel,
+            outputFormat,
+            finalOnly,
+            stdout,
+            stderr,
+          );
+        } else {
+          await runPromptTurn(session, opts.prompt!, outputFormat, finalOnly, stdout, stderr);
+        }
+      }
+    } catch (error) {
+      // A turn-level failure is reported through the chosen output format (so a
+      // stream-json consumer keeps receiving JSON) and mapped to an exit code;
+      // setup errors (no model, session not found, …) are not PromptTurnErrors
+      // and propagate to the top-level handler instead.
+      if (!(error instanceof PromptTurnError)) throw error;
+      emitPromptError(error, outputFormat, stdout, stderr);
+      process.exitCode = error.retryable ? CLI_EXIT_RETRYABLE : CLI_EXIT_FAILURE;
+    }
+    // Give background tasks a chance to finish before the session is closed (and
+    // any stragglers killed). Gated by the same `keepAliveOnExit` config the
+    // session uses: when keep-alive is on, tasks are left running and we skip the
+    // wait entirely.
+    await drainBackgroundTasksOnExit(
+      session,
+      resolveKeepAliveOnExit(config, process.env),
+      resolvePrintWaitCeilingMs(config),
+      outputFormat,
+      stdout,
+      stderr,
+      io.clock ?? defaultPromptClock,
+    );
+    // `--final-message-only` keeps stdout to just the answer(s), so the resume
+    // hint is suppressed in that mode.
+    if (!finalOnly) {
+      writeResumeHint(session.id, outputFormat, stdout, stderr);
     }
-    writeResumeHint(session.id, outputFormat, stdout, stderr);
 
     withTelemetryContext({ sessionId: session.id }).track('exit', {
       duration_ms: Date.now() - startedAt,
@@ -165,6 +259,7 @@ async function runHeadlessGoal(
   goal: HeadlessGoalCreate,
   model: string | undefined,
   outputFormat: PromptOutputFormat,
+  finalOnly: boolean,
   stdout: PromptOutput,
   stderr: PromptOutput,
 ): Promise<void> {
@@ -187,7 +282,7 @@ async function runHeadlessGoal(
   try {
     // The objective is sent as the normal prompt; goal continuation keeps the
     // turn alive until a terminal state is reached.
-    await runPromptTurn(session, goal.objective, outputFormat, stdout, stderr);
+    await runPromptTurn(session, goal.objective, outputFormat, finalOnly, stdout, stderr);
   } finally {
     unsubscribeGoalEvents();
     const snapshot = completedSnapshot ?? (await session.getGoal()).goal;
@@ -382,15 +477,13 @@ function runPromptTurn(
   session: Session,
   prompt: string,
   outputFormat: PromptOutputFormat,
+  finalOnly: boolean,
   stdout: PromptOutput,
   stderr: PromptOutput,
 ): Promise<void> {
   let activeTurnId: number | undefined;
   let activeAgentId: string | undefined;
-  const outputWriter =
-    outputFormat === 'stream-json'
-      ? new PromptJsonWriter(stdout)
-      : new PromptTranscriptWriter(stdout, stderr);
+  const outputWriter = createPromptTurnWriter(outputFormat, finalOnly, stdout, stderr);
   let settled = false;
   let unsubscribe: (() => void) | undefined;
 
@@ -408,11 +501,18 @@ function runPromptTurn(
     };
 
     unsubscribe = session.onEvent((event) => {
+      // Session-level notifications (background tasks, cron) are not tied to the
+      // main turn, so they are surfaced before the turn/agent filter below.
+      const notification = toNotificationMessage(event);
+      if (notification !== undefined) {
+        outputWriter.writeNotification(notification);
+        return;
+      }
       if (event.type === 'error') {
         if (event.agentId !== PROMPT_MAIN_AGENT_ID) {
           return;
         }
-        finish(new Error(`${event.code}: ${event.message}`));
+        finish(new PromptTurnError(event.code, event.message, event.retryable === true));
         return;
       }
       if (event.type === 'turn.started' && activeTurnId === undefined) {
@@ -470,7 +570,7 @@ function runPromptTurn(
             finish();
             return;
           }
-          finish(new Error(formatTurnEndedFailure(event)));
+          finish(turnEndedError(event));
           return;
         case 'agent.status.updated':
         case 'background.task.started':
@@ -498,7 +598,7 @@ function runPromptTurn(
     });
 
     session.prompt(prompt).catch((error: unknown) => {
-      finish(error instanceof Error ? error : new Error(String(error)));
+      finish(toPromptTurnError(error));
     });
   });
 }
@@ -514,11 +614,26 @@ interface PromptTurnWriter {
     argumentsPart: string | undefined,
   ): void;
   writeToolResult(toolCallId: string, output: unknown): void;
+  writeNotification(message: PromptJsonNotificationMessage): void;
   flushAssistant(): void;
   discardAssistant(): void;
   finish(): void;
 }
 
+function createPromptTurnWriter(
+  outputFormat: PromptOutputFormat,
+  finalOnly: boolean,
+  stdout: PromptOutput,
+  stderr: PromptOutput,
+): PromptTurnWriter {
+  if (outputFormat === 'stream-json') {
+    return finalOnly ? new PromptFinalJsonWriter(stdout) : new PromptJsonWriter(stdout);
+  }
+  return finalOnly
+    ? new PromptFinalTextWriter(stdout)
+    : new PromptTranscriptWriter(stdout, stderr);
+}
+
 class PromptTranscriptWriter implements PromptTurnWriter {
   private readonly assistantWriter: PromptBlockWriter;
   private readonly thinkingWriter: PromptBlockWriter;
@@ -550,6 +665,8 @@ class PromptTranscriptWriter implements PromptTurnWriter {
 
   writeToolResult(): void {}
 
+  writeNotification(): void {}
+
   flushAssistant(): void {}
 
   discardAssistant(): void {}
@@ -581,6 +698,35 @@ interface PromptJsonToolMessage {
   content: string;
 }
 
+interface PromptJsonThinkingMessage {
+  role: 'assistant';
+  type: 'thinking';
+  content: string;
+}
+
+/**
+ * Asynchronous, non-turn notifications (background tasks, cron) surfaced as
+ * their own JSONL line. `event` carries the originating session event type; the
+ * remaining fields are event-specific.
+ */
+interface PromptJsonNotificationMessage {
+  type: 'notification';
+  event: string;
+  taskId?: string;
+  kind?: string;
+  status?: string;
+  description?: string;
+  prompt?: string;
+}
+
+/** A turn-level failure surfaced as its own JSONL line in `stream-json` mode. */
+interface PromptJsonErrorMessage {
+  type: 'error';
+  code: string;
+  message: string;
+  retryable: boolean;
+}
+
 interface PromptJsonResumeMetaMessage {
   role: 'meta';
   type: 'session.resume_hint';
@@ -613,6 +759,7 @@ function writeResumeHint(
 
 class PromptJsonWriter implements PromptTurnWriter {
   private assistantText = '';
+  private thinkingText = '';
   private readonly toolCalls: PromptJsonToolCall[] = [];
 
   constructor(private readonly stdout: PromptOutput) {}
@@ -629,7 +776,16 @@ class PromptJsonWriter implements PromptTurnWriter {
     });
   }
 
-  writeThinkingDelta(): void {}
+  writeThinkingDelta(delta: string): void {
+    this.thinkingText += delta;
+  }
+
+  writeNotification(message: PromptJsonNotificationMessage): void {
+    // Flush any in-flight assistant/thinking content first so the notification
+    // never splits a streaming assistant message.
+    this.flushAssistant();
+    this.writeJsonLine(message);
+  }
 
   writeToolCall(toolCallId: string, name: string, args: unknown): void {
     const existing = this.toolCalls.find((toolCall) => toolCall.id === toolCallId);
@@ -672,6 +828,9 @@ class PromptJsonWriter implements PromptTurnWriter {
   }
 
   flushAssistant(): void {
+    // Thinking precedes the assistant/tool output of the same step so a viewer
+    // can render the reasoning before the answer it produced.
+    this.flushThinking();
     if (this.assistantText.length === 0 && this.toolCalls.length === 0) return;
     const message: PromptJsonAssistantMessage = {
       role: 'assistant',
@@ -684,6 +843,7 @@ class PromptJsonWriter implements PromptTurnWriter {
 
   discardAssistant(): void {
     this.assistantText = '';
+    this.thinkingText = '';
     this.toolCalls.length = 0;
   }
 
@@ -691,6 +851,16 @@ class PromptJsonWriter implements PromptTurnWriter {
     this.flushAssistant();
   }
 
+  private flushThinking(): void {
+    if (this.thinkingText.length === 0) return;
+    this.writeJsonLine({
+      role: 'assistant',
+      type: 'thinking',
+      content: this.thinkingText,
+    });
+    this.thinkingText = '';
+  }
+
   private findOrCreateToolCall(toolCallId: string, name: string): PromptJsonToolCall {
     const existing = this.toolCalls.find((toolCall) => toolCall.id === toolCallId);
     if (existing !== undefined) return existing;
@@ -706,11 +876,97 @@ class PromptJsonWriter implements PromptTurnWriter {
     return toolCall;
   }
 
-  private writeJsonLine(message: PromptJsonAssistantMessage | PromptJsonToolMessage): void {
+  private writeJsonLine(
+    message:
+      | PromptJsonAssistantMessage
+      | PromptJsonToolMessage
+      | PromptJsonThinkingMessage
+      | PromptJsonNotificationMessage,
+  ): void {
     this.stdout.write(`${JSON.stringify(message)}\n`);
   }
 }
 
+/**
+ * `--final-message-only` + `stream-json`: emit exactly one assistant message per
+ * turn — the final step's text. Thinking, tool calls/results and notifications
+ * are dropped. Each step boundary discards the previous step's buffer so only
+ * the last step survives to `finish()`.
+ */
+class PromptFinalJsonWriter implements PromptTurnWriter {
+  private assistantText = '';
+
+  constructor(private readonly stdout: PromptOutput) {}
+
+  writeAssistantDelta(delta: string): void {
+    this.assistantText += delta;
+  }
+
+  writeHookResult(): void {}
+
+  writeThinkingDelta(): void {}
+
+  writeToolCall(): void {}
+
+  writeToolCallDelta(): void {}
+
+  writeToolResult(): void {}
+
+  writeNotification(): void {}
+
+  flushAssistant(): void {
+    // A new step supersedes the previous one; keep only the latest step's text.
+    this.assistantText = '';
+  }
+
+  discardAssistant(): void {
+    this.assistantText = '';
+  }
+
+  finish(): void {
+    this.stdout.write(`${JSON.stringify({ role: 'assistant', content: this.assistantText })}\n`);
+  }
+}
+
+/**
+ * `--final-message-only` + `text`: emit only the final step's assistant text.
+ */
+class PromptFinalTextWriter implements PromptTurnWriter {
+  private assistantText = '';
+
+  constructor(private readonly stdout: PromptOutput) {}
+
+  writeAssistantDelta(delta: string): void {
+    this.assistantText += delta;
+  }
+
+  writeHookResult(): void {}
+
+  writeThinkingDelta(): void {}
+
+  writeToolCall(): void {}
+
+  writeToolCallDelta(): void {}
+
+  writeToolResult(): void {}
+
+  writeNotification(): void {}
+
+  flushAssistant(): void {
+    this.assistantText = '';
+  }
+
+  discardAssistant(): void {
+    this.assistantText = '';
+  }
+
+  finish(): void {
+    if (this.assistantText.length > 0) {
+      this.stdout.write(`${this.assistantText}\n`);
+    }
+  }
+}
+
 class PromptBlockWriter {
   private started = false;
   private atLineStart = false;
@@ -804,10 +1060,249 @@ function hasTurnId(event: Event): event is Event & { readonly turnId: number } {
   return 'turnId' in event;
 }
 
-function formatTurnEndedFailure(event: Extract<Event, { type: 'turn.ended' }>): string {
-  if (event.error !== undefined) return `${event.error.code}: ${event.error.message}`;
-  if (event.reason === 'filtered') {
-    return 'Provider safety policy blocked the response.';
+function turnEndedError(event: Extract<Event, { type: 'turn.ended' }>): PromptTurnError {
+  if (event.error !== undefined) {
+    return new PromptTurnError(
+      event.error.code,
+      event.error.message,
+      event.error.retryable === true,
+    );
   }
-  return `Prompt turn ended with reason: ${event.reason}`;
+  if (event.reason === 'filtered') {
+    return new PromptTurnError(
+      'provider.filtered',
+      'Provider safety policy blocked the response.',
+      false,
+    );
+  }
+  return new PromptTurnError(
+    `turn.${event.reason}`,
+    `Prompt turn ended with reason: ${event.reason}`,
+    false,
+  );
+}
+
+/** Normalizes an error thrown by `session.prompt()` into a {@link PromptTurnError}. */
+function toPromptTurnError(error: unknown): PromptTurnError {
+  if (error instanceof PromptTurnError) return error;
+  if (error !== null && typeof error === 'object') {
+    const payload = error as { code?: unknown; message?: unknown; retryable?: unknown };
+    if (typeof payload.code === 'string' && typeof payload.message === 'string') {
+      return new PromptTurnError(payload.code, payload.message, payload.retryable === true);
+    }
+  }
+  return new PromptTurnError('internal', error instanceof Error ? error.message : String(error), false);
+}
+
+/**
+ * Reports a turn-level failure through the active output format: a structured
+ * `{"type":"error",…}` JSONL line on stdout for `stream-json`, or a plain-text
+ * line on stderr for `text` (keeping `stream-json` stdout entirely JSON).
+ */
+function emitPromptError(
+  error: PromptTurnError,
+  outputFormat: PromptOutputFormat,
+  stdout: PromptOutput,
+  stderr: PromptOutput,
+): void {
+  if (outputFormat === 'stream-json') {
+    const message: PromptJsonErrorMessage = {
+      type: 'error',
+      code: error.code,
+      message: error.detail,
+      retryable: error.retryable,
+    };
+    stdout.write(`${JSON.stringify(message)}\n`);
+    return;
+  }
+  stderr.write(`Error: ${error.message}\n`);
+}
+
+const defaultPromptClock: PromptClock = {
+  now: () => Date.now(),
+  sleep: (ms) =>
+    new Promise((resolve) => {
+      setTimeout(resolve, ms);
+    }),
+};
+
+/**
+ * Waits for active background tasks to finish before the session is closed,
+ * bounded by the print-wait ceiling. Skipped entirely when `keepAliveOnExit` is
+ * set (tasks are intentionally left running). In `stream-json` mode each task's
+ * terminal outcome is surfaced as a notification line while waiting.
+ */
+async function drainBackgroundTasksOnExit(
+  session: Session,
+  keepAliveOnExit: boolean,
+  ceilingMs: number,
+  outputFormat: PromptOutputFormat,
+  stdout: PromptOutput,
+  stderr: PromptOutput,
+  clock: PromptClock,
+): Promise<void> {
+  if (keepAliveOnExit) return;
+  let active = await session.listBackgroundTasks({ activeOnly: true });
+  if (active.length === 0) return;
+  const unsubscribe =
+    outputFormat === 'stream-json'
+      ? session.onEvent((event) => {
+          const notification = toNotificationMessage(event);
+          if (notification?.event === 'background.task.terminated') {
+            stdout.write(`${JSON.stringify(notification)}\n`);
+          }
+        })
+      : undefined;
+  try {
+    const deadline = clock.now() + ceilingMs;
+    while (active.length > 0) {
+      if (clock.now() >= deadline) {
+        stderr.write(
+          `Timed out after ${Math.round(ceilingMs / 1000)}s waiting for ${active.length} background task(s); they will be stopped.\n`,
+        );
+        return;
+      }
+      await clock.sleep(BACKGROUND_DRAIN_POLL_MS);
+      active = await session.listBackgroundTasks({ activeOnly: true });
+    }
+  } finally {
+    unsubscribe?.();
+  }
+}
+
+/**
+ * Resolves whether background tasks are kept alive past exit, mirroring the
+ * session resolver: env override, then config, defaulting to false (drain).
+ */
+function resolveKeepAliveOnExit(
+  config: { readonly background?: unknown },
+  env: NodeJS.ProcessEnv,
+): boolean {
+  const envValue = parsePromptBooleanEnv(env[BACKGROUND_KEEP_ALIVE_ON_EXIT_ENV]);
+  if (envValue !== undefined) return envValue;
+  const background = config.background as { keepAliveOnExit?: unknown } | undefined;
+  return typeof background?.keepAliveOnExit === 'boolean' ? background.keepAliveOnExit : false;
+}
+
+/** Resolves the background-drain ceiling in milliseconds from config. */
+function resolvePrintWaitCeilingMs(config: { readonly background?: unknown }): number {
+  const background = config.background as { printWaitCeilingS?: unknown } | undefined;
+  const seconds =
+    typeof background?.printWaitCeilingS === 'number' && background.printWaitCeilingS > 0
+      ? background.printWaitCeilingS
+      : DEFAULT_PRINT_WAIT_CEILING_S;
+  return seconds * 1000;
+}
+
+function parsePromptBooleanEnv(value: string | undefined): boolean | undefined {
+  if (value === undefined) return undefined;
+  const normalized = value.trim().toLowerCase();
+  if (normalized === '1' || normalized === 'true' || normalized === 'yes' || normalized === 'on') {
+    return true;
+  }
+  if (
+    normalized === '0' ||
+    normalized === 'false' ||
+    normalized === 'no' ||
+    normalized === 'off'
+  ) {
+    return false;
+  }
+  return undefined;
+}
+
+/**
+ * Maps session-level notification events (background tasks, cron) to a JSONL
+ * notification line, or `undefined` for events that are not notifications.
+ */
+function toNotificationMessage(event: Event): PromptJsonNotificationMessage | undefined {
+  switch (event.type) {
+    case 'background.task.started':
+    case 'background.task.terminated':
+      return {
+        type: 'notification',
+        event: event.type,
+        taskId: event.info.taskId,
+        kind: event.info.kind,
+        status: event.info.status,
+        description: event.info.description,
+      };
+    case 'cron.fired':
+      return {
+        type: 'notification',
+        event: 'cron.fired',
+        prompt: event.prompt,
+      };
+    default:
+      return undefined;
+  }
+}
+
+/** Default `--input-format` line source: a reader over the given stdin stream. */
+function defaultStdinLines(input: NodeJS.ReadableStream): AsyncIterable<string> {
+  return createInterface({ input, crlfDelay: Infinity });
+}
+
+/** Joins all input lines into a single string (for `--input-format text`). */
+async function collectLines(lines: AsyncIterable<string>): Promise<string> {
+  const collected: string[] = [];
+  for await (const line of lines) {
+    collected.push(line);
+  }
+  return collected.join('\n');
+}
+
+/**
+ * Yields a prompt command per `user` message read from stdin as JSONL. Blank
+ * lines, malformed JSON and non-`user` messages are skipped with a stderr note,
+ * matching the kimi-cli `stream-json` input contract.
+ */
+async function* readUserCommands(
+  lines: AsyncIterable<string>,
+  stderr: PromptOutput,
+): AsyncGenerator<string> {
+  for await (const raw of lines) {
+    const line = raw.trim();
+    if (line.length === 0) continue;
+    let parsed: unknown;
+    try {
+      parsed = JSON.parse(line);
+    } catch {
+      stderr.write(`Ignoring invalid JSON input line: ${line}\n`);
+      continue;
+    }
+    const command = extractUserCommand(parsed);
+    if (command === undefined) {
+      stderr.write(`Ignoring non-user input message: ${line}\n`);
+      continue;
+    }
+    if (command.length === 0) continue;
+    yield command;
+  }
+}
+
+/** Extracts the prompt text from a parsed `user` message, or `undefined`. */
+function extractUserCommand(parsed: unknown): string | undefined {
+  if (typeof parsed !== 'object' || parsed === null) return undefined;
+  const message = parsed as { role?: unknown; content?: unknown };
+  if (message.role !== 'user') return undefined;
+  return extractMessageText(message.content);
+}
+
+/** Concatenates the text of a message's content (string or content-part array). */
+function extractMessageText(content: unknown): string {
+  if (typeof content === 'string') return content.trim();
+  if (!Array.isArray(content)) return '';
+  const texts: string[] = [];
+  for (const part of content) {
+    if (
+      typeof part === 'object' &&
+      part !== null &&
+      (part as { type?: unknown }).type === 'text' &&
+      typeof (part as { text?: unknown }).text === 'string'
+    ) {
+      texts.push((part as { text: string }).text);
+    }
+  }
+  return texts.join('\n').trim();
 }
diff --git a/apps/kimi-code/test/cli/goal-prompt.test.ts b/apps/kimi-code/test/cli/goal-prompt.test.ts
index 04780bd26..4cbf33365 100644
--- a/apps/kimi-code/test/cli/goal-prompt.test.ts
+++ b/apps/kimi-code/test/cli/goal-prompt.test.ts
@@ -90,6 +90,7 @@ const mocks = vi.hoisted(() => {
       eventHandlers.add(handler);
       return () => eventHandlers.delete(handler);
     }),
+    listBackgroundTasks: vi.fn(async () => [] as readonly unknown[]),
     prompt: vi.fn(async () => {
       for (const handler of eventHandlers) {
         handler(mainEvent({ type: 'turn.started', turnId: 1, origin: { kind: 'user' } }));
diff --git a/apps/kimi-code/test/cli/options.test.ts b/apps/kimi-code/test/cli/options.test.ts
index 73d759841..c5ce73738 100644
--- a/apps/kimi-code/test/cli/options.test.ts
+++ b/apps/kimi-code/test/cli/options.test.ts
@@ -303,6 +303,83 @@ describe('CLI options parsing', () => {
     });
   });
 
+  describe('--input-format', () => {
+    it('parses --input-format stream-json and enters print mode without --prompt', () => {
+      const opts = parse(['--input-format', 'stream-json']);
+      expect(opts.inputFormat).toBe('stream-json');
+      expect(opts.prompt).toBeUndefined();
+      expect(validateOptions(opts).uiMode).toBe('print');
+    });
+
+    it('parses --input-format text and enters print mode', () => {
+      const opts = parse(['--input-format=text']);
+      expect(opts.inputFormat).toBe('text');
+      expect(validateOptions(opts).uiMode).toBe('print');
+    });
+
+    it('allows --input-format with --output-format stream-json', () => {
+      const opts = parse(['--input-format', 'stream-json', '--output-format', 'stream-json']);
+      expect(opts.inputFormat).toBe('stream-json');
+      expect(opts.outputFormat).toBe('stream-json');
+      expect(validateOptions(opts).uiMode).toBe('print');
+    });
+
+    it('rejects combining --prompt with --input-format', () => {
+      const opts = parse(['-p', 'hi', '--input-format', 'stream-json']);
+      expect(() => validateOptions(opts)).toThrow(OptionConflictError);
+      expect(() => validateOptions(opts)).toThrow(
+        'Cannot combine --prompt with --input-format; the prompt is read from stdin.',
+      );
+    });
+
+    it('rejects an unknown --input-format value', () => {
+      expect(() => parse(['--input-format', 'yaml'])).toThrow();
+    });
+  });
+
+  describe('--final-message-only', () => {
+    it('defaults to false', () => {
+      expect(parse([]).finalMessageOnly).toBe(false);
+    });
+
+    it('parses --final-message-only in prompt mode', () => {
+      const opts = parse(['-p', 'hi', '--final-message-only']);
+      expect(opts.finalMessageOnly).toBe(true);
+      expect(validateOptions(opts).uiMode).toBe('print');
+    });
+
+    it('rejects --final-message-only outside prompt mode', () => {
+      const opts = parse(['--final-message-only']);
+      expect(() => validateOptions(opts)).toThrow(OptionConflictError);
+      expect(() => validateOptions(opts)).toThrow(
+        'Final-message-only output is only supported in prompt mode.',
+      );
+    });
+  });
+
+  describe('--quiet', () => {
+    it('defaults to false', () => {
+      expect(parse([]).quiet).toBe(false);
+    });
+
+    it('enters print mode on its own', () => {
+      const opts = parse(['--quiet']);
+      expect(opts.quiet).toBe(true);
+      expect(validateOptions(opts).uiMode).toBe('print');
+    });
+
+    it('is allowed alongside an explicit --output-format text', () => {
+      const opts = parse(['--quiet', '--output-format', 'text']);
+      expect(() => validateOptions(opts)).not.toThrow();
+    });
+
+    it('rejects --quiet with --output-format stream-json', () => {
+      const opts = parse(['--quiet', '--output-format', 'stream-json']);
+      expect(() => validateOptions(opts)).toThrow(OptionConflictError);
+      expect(() => validateOptions(opts)).toThrow('Quiet mode implies --output-format text.');
+    });
+  });
+
   describe('--skills-dir', () => {
     it('collects repeated skill directories', () => {
       expect(parse(['--skills-dir', '/one', '--skills-dir=/two']).skillsDirs).toEqual([
@@ -408,9 +485,6 @@ describe('CLI options parsing', () => {
         '--agent=default',
         '--raw-model',
         '--config-file=x',
-        '--quiet',
-        '--final-message-only',
-        '--input-format=text',
         '--agent-file=x',
         '--mcp-config={}',
         '--mcp-config-file=/',
diff --git a/apps/kimi-code/test/cli/run-prompt.test.ts b/apps/kimi-code/test/cli/run-prompt.test.ts
index 0d1fc3ea1..cec907ca7 100644
--- a/apps/kimi-code/test/cli/run-prompt.test.ts
+++ b/apps/kimi-code/test/cli/run-prompt.test.ts
@@ -1,5 +1,5 @@
 import type { createKimiDeviceId as createKimiDeviceIdFn } from '@moonshot-ai/kimi-code-oauth';
-import { afterEach, describe, expect, it, vi } from 'vitest';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
 
 import { runPrompt } from '#/cli/run-prompt';
 
@@ -13,6 +13,14 @@ const mocks = vi.hoisted(() => {
     ...event,
   });
   const mainEvent = (event: Record<string, unknown>) => agentEvent('main', event);
+  const defaultPromptImpl = async (_command?: string) => {
+    for (const handler of eventHandlers) {
+      handler(mainEvent({ type: 'turn.started', turnId: 1, origin: { kind: 'user' } }));
+      handler(mainEvent({ type: 'assistant.delta', turnId: 1, delta: 'hello' }));
+      handler(mainEvent({ type: 'assistant.delta', turnId: 1, delta: ' world' }));
+      handler(mainEvent({ type: 'turn.ended', turnId: 1, reason: 'completed' }));
+    }
+  };
   const session = {
     id: 'ses_prompt',
     setModel: vi.fn(),
@@ -28,16 +36,8 @@ const mocks = vi.hoisted(() => {
       eventHandlers.add(handler);
       return () => eventHandlers.delete(handler);
     }),
-    prompt: vi.fn(async () => {
-      for (const handler of eventHandlers) {
-        handler(
-          mainEvent({ type: 'turn.started', turnId: 1, origin: { kind: 'user' } }),
-        );
-        handler(mainEvent({ type: 'assistant.delta', turnId: 1, delta: 'hello' }));
-        handler(mainEvent({ type: 'assistant.delta', turnId: 1, delta: ' world' }));
-        handler(mainEvent({ type: 'turn.ended', turnId: 1, reason: 'completed' }));
-      }
-    }),
+    listBackgroundTasks: vi.fn(async () => [] as readonly unknown[]),
+    prompt: vi.fn(defaultPromptImpl),
   };
 
   return {
@@ -45,6 +45,7 @@ const mocks = vi.hoisted(() => {
     eventHandlers,
     agentEvent,
     mainEvent,
+    defaultPromptImpl,
     kimiHarnessConstructor: vi.fn(),
     harnessEnsureConfigFile: vi.fn(),
     harnessGetConfig: vi.fn(
@@ -133,6 +134,8 @@ function opts(overrides: Partial<Parameters<typeof runPrompt>[0]> = {}) {
     plan: false,
     model: undefined,
     outputFormat: undefined,
+    inputFormat: undefined,
+    finalMessageOnly: false,
     prompt: 'say hello',
     skillsDirs: [],
     addDirs: [],
@@ -183,9 +186,18 @@ async function waitForAssertion(assertion: () => void): Promise<void> {
 }
 
 describe('runPrompt', () => {
+  let savedExitCode: typeof process.exitCode;
+
+  beforeEach(() => {
+    savedExitCode = process.exitCode;
+  });
+
   afterEach(() => {
+    process.exitCode = savedExitCode;
     vi.clearAllMocks();
     mocks.eventHandlers.clear();
+    mocks.session.prompt.mockImplementation(mocks.defaultPromptImpl);
+    mocks.session.listBackgroundTasks.mockResolvedValue([]);
     mocks.createKimiDeviceId.mockImplementation(() => 'device-1');
     mocks.resolveKimiHome.mockImplementation(
       (homeDir?: string) => homeDir ?? '/tmp/kimi-code-test-home',
@@ -571,6 +583,331 @@ describe('runPrompt', () => {
     );
   });
 
+  it('writes stream-json thinking as its own JSONL line before the assistant content', async () => {
+    mocks.session.prompt.mockImplementationOnce(async () => {
+      for (const handler of mocks.eventHandlers) {
+        handler(mocks.mainEvent({ type: 'turn.started', turnId: 9, origin: { kind: 'user' } }));
+        handler(mocks.mainEvent({ type: 'thinking.delta', turnId: 9, delta: 'let me ' }));
+        handler(mocks.mainEvent({ type: 'thinking.delta', turnId: 9, delta: 'think' }));
+        handler(mocks.mainEvent({ type: 'assistant.delta', turnId: 9, delta: 'the answer' }));
+        handler(mocks.mainEvent({ type: 'turn.ended', turnId: 9, reason: 'completed' }));
+      }
+    });
+    const stdout = writer();
+    const stderr = writer();
+
+    await runPrompt(opts({ outputFormat: 'stream-json' }), '1.2.3-test', { stdout, stderr });
+
+    expect(stdout.text()).toBe(
+      [
+        '{"role":"assistant","type":"thinking","content":"let me think"}',
+        '{"role":"assistant","content":"the answer"}',
+        '{"role":"meta","type":"session.resume_hint","session_id":"ses_prompt","command":"kimi -r ses_prompt","content":"To resume this session: kimi -r ses_prompt"}',
+        '',
+      ].join('\n'),
+    );
+    expect(stderr.text()).toBe('');
+  });
+
+  it('writes stream-json thinking before tool calls and keeps the full chain order', async () => {
+    mocks.session.prompt.mockImplementationOnce(async () => {
+      for (const handler of mocks.eventHandlers) {
+        handler(mocks.mainEvent({ type: 'turn.started', turnId: 10, origin: { kind: 'user' } }));
+        handler(mocks.mainEvent({ type: 'thinking.delta', turnId: 10, delta: 'inspect dir' }));
+        handler(
+          mocks.mainEvent({
+            type: 'tool.call.started',
+            turnId: 10,
+            toolCallId: 'tc_1',
+            name: 'Bash',
+            args: { command: 'ls' },
+          }),
+        );
+        handler(
+          mocks.mainEvent({ type: 'tool.result', turnId: 10, toolCallId: 'tc_1', output: 'file1' }),
+        );
+        handler(mocks.mainEvent({ type: 'assistant.delta', turnId: 10, delta: 'found it' }));
+        handler(mocks.mainEvent({ type: 'turn.ended', turnId: 10, reason: 'completed' }));
+      }
+    });
+    const stdout = writer();
+    const stderr = writer();
+
+    await runPrompt(opts({ outputFormat: 'stream-json' }), '1.2.3-test', { stdout, stderr });
+
+    expect(stdout.text()).toBe(
+      [
+        '{"role":"assistant","type":"thinking","content":"inspect dir"}',
+        '{"role":"assistant","tool_calls":[{"type":"function","id":"tc_1","function":{"name":"Bash","arguments":"{\\"command\\":\\"ls\\"}"}}]}',
+        '{"role":"tool","tool_call_id":"tc_1","content":"file1"}',
+        '{"role":"assistant","content":"found it"}',
+        '{"role":"meta","type":"session.resume_hint","session_id":"ses_prompt","command":"kimi -r ses_prompt","content":"To resume this session: kimi -r ses_prompt"}',
+        '',
+      ].join('\n'),
+    );
+  });
+
+  it('flushes stream-json thinking at each step boundary within a turn', async () => {
+    mocks.session.prompt.mockImplementationOnce(async () => {
+      for (const handler of mocks.eventHandlers) {
+        handler(mocks.mainEvent({ type: 'turn.started', turnId: 11, origin: { kind: 'user' } }));
+        handler(
+          mocks.mainEvent({ type: 'thinking.delta', turnId: 11, delta: 'step one thinking' }),
+        );
+        handler(
+          mocks.mainEvent({
+            type: 'tool.call.started',
+            turnId: 11,
+            toolCallId: 'tc_1',
+            name: 'Bash',
+            args: { command: 'ls' },
+          }),
+        );
+        handler(
+          mocks.mainEvent({ type: 'tool.result', turnId: 11, toolCallId: 'tc_1', output: 'ok' }),
+        );
+        handler(
+          mocks.mainEvent({ type: 'thinking.delta', turnId: 11, delta: 'step two thinking' }),
+        );
+        handler(mocks.mainEvent({ type: 'assistant.delta', turnId: 11, delta: 'all done' }));
+        handler(mocks.mainEvent({ type: 'turn.ended', turnId: 11, reason: 'completed' }));
+      }
+    });
+    const stdout = writer();
+    const stderr = writer();
+
+    await runPrompt(opts({ outputFormat: 'stream-json' }), '1.2.3-test', { stdout, stderr });
+
+    expect(stdout.text()).toBe(
+      [
+        '{"role":"assistant","type":"thinking","content":"step one thinking"}',
+        '{"role":"assistant","tool_calls":[{"type":"function","id":"tc_1","function":{"name":"Bash","arguments":"{\\"command\\":\\"ls\\"}"}}]}',
+        '{"role":"tool","tool_call_id":"tc_1","content":"ok"}',
+        '{"role":"assistant","type":"thinking","content":"step two thinking"}',
+        '{"role":"assistant","content":"all done"}',
+        '{"role":"meta","type":"session.resume_hint","session_id":"ses_prompt","command":"kimi -r ses_prompt","content":"To resume this session: kimi -r ses_prompt"}',
+        '',
+      ].join('\n'),
+    );
+  });
+
+  it('discards partial stream-json thinking when a step retries', async () => {
+    mocks.session.prompt.mockImplementationOnce(async () => {
+      for (const handler of mocks.eventHandlers) {
+        handler(mocks.mainEvent({ type: 'turn.started', turnId: 12, origin: { kind: 'user' } }));
+        handler(mocks.mainEvent({ type: 'thinking.delta', turnId: 12, delta: 'wrong path' }));
+        handler(mocks.mainEvent({ type: 'assistant.delta', turnId: 12, delta: 'partial' }));
+        handler(mocks.mainEvent({ type: 'turn.step.retrying', turnId: 12 }));
+        handler(mocks.mainEvent({ type: 'thinking.delta', turnId: 12, delta: 'right path' }));
+        handler(mocks.mainEvent({ type: 'assistant.delta', turnId: 12, delta: 'final' }));
+        handler(mocks.mainEvent({ type: 'turn.ended', turnId: 12, reason: 'completed' }));
+      }
+    });
+    const stdout = writer();
+    const stderr = writer();
+
+    await runPrompt(opts({ outputFormat: 'stream-json' }), '1.2.3-test', { stdout, stderr });
+
+    expect(stdout.text()).toBe(
+      [
+        '{"role":"assistant","type":"thinking","content":"right path"}',
+        '{"role":"assistant","content":"final"}',
+        '{"role":"meta","type":"session.resume_hint","session_id":"ses_prompt","command":"kimi -r ses_prompt","content":"To resume this session: kimi -r ses_prompt"}',
+        '',
+      ].join('\n'),
+    );
+  });
+
+  it('emits notification events as JSON lines, flushing the assistant first (output C)', async () => {
+    mocks.session.prompt.mockImplementationOnce(async () => {
+      for (const handler of mocks.eventHandlers) {
+        handler(mocks.mainEvent({ type: 'turn.started', turnId: 30, origin: { kind: 'user' } }));
+        handler(mocks.mainEvent({ type: 'assistant.delta', turnId: 30, delta: 'starting' }));
+        handler(
+          mocks.mainEvent({
+            type: 'background.task.terminated',
+            info: {
+              taskId: 'b1',
+              kind: 'agent',
+              status: 'completed',
+              description: 'build',
+              startedAt: 0,
+              endedAt: 1,
+            },
+          }),
+        );
+        handler(mocks.mainEvent({ type: 'assistant.delta', turnId: 30, delta: 'done' }));
+        handler(mocks.mainEvent({ type: 'turn.ended', turnId: 30, reason: 'completed' }));
+      }
+    });
+    const stdout = writer();
+    const stderr = writer();
+
+    await runPrompt(opts({ outputFormat: 'stream-json' }), '1.2.3-test', { stdout, stderr });
+
+    expect(stdout.text()).toBe(
+      [
+        '{"role":"assistant","content":"starting"}',
+        '{"type":"notification","event":"background.task.terminated","taskId":"b1","kind":"agent","status":"completed","description":"build"}',
+        '{"role":"assistant","content":"done"}',
+        '{"role":"meta","type":"session.resume_hint","session_id":"ses_prompt","command":"kimi -r ses_prompt","content":"To resume this session: kimi -r ses_prompt"}',
+        '',
+      ].join('\n'),
+    );
+  });
+
+  it('does not emit notification JSON in text output mode (output C)', async () => {
+    mocks.session.prompt.mockImplementationOnce(async () => {
+      for (const handler of mocks.eventHandlers) {
+        handler(mocks.mainEvent({ type: 'turn.started', turnId: 31, origin: { kind: 'user' } }));
+        handler(
+          mocks.mainEvent({
+            type: 'background.task.terminated',
+            info: {
+              taskId: 'b1',
+              kind: 'process',
+              status: 'completed',
+              description: 'build',
+              startedAt: 0,
+              endedAt: 1,
+            },
+          }),
+        );
+        handler(mocks.mainEvent({ type: 'assistant.delta', turnId: 31, delta: 'ok' }));
+        handler(mocks.mainEvent({ type: 'turn.ended', turnId: 31, reason: 'completed' }));
+      }
+    });
+    const stdout = writer();
+    const stderr = writer();
+
+    await runPrompt(opts(), '1.2.3-test', { stdout, stderr });
+
+    expect(stdout.text()).toBe('• ok\n\n');
+    expect(stdout.text()).not.toContain('notification');
+  });
+
+  it('emits only the final assistant message in stream-json final-message-only mode (output B)', async () => {
+    mocks.session.prompt.mockImplementationOnce(async () => {
+      for (const handler of mocks.eventHandlers) {
+        handler(mocks.mainEvent({ type: 'turn.started', turnId: 40, origin: { kind: 'user' } }));
+        handler(mocks.mainEvent({ type: 'turn.step.started', turnId: 40 }));
+        handler(mocks.mainEvent({ type: 'thinking.delta', turnId: 40, delta: 'secret' }));
+        handler(mocks.mainEvent({ type: 'assistant.delta', turnId: 40, delta: 'first step' }));
+        handler(mocks.mainEvent({ type: 'turn.step.started', turnId: 40 }));
+        handler(mocks.mainEvent({ type: 'assistant.delta', turnId: 40, delta: 'final' }));
+        handler(mocks.mainEvent({ type: 'assistant.delta', turnId: 40, delta: ' answer' }));
+        handler(mocks.mainEvent({ type: 'turn.ended', turnId: 40, reason: 'completed' }));
+      }
+    });
+    const stdout = writer();
+    const stderr = writer();
+
+    await runPrompt(opts({ outputFormat: 'stream-json', finalMessageOnly: true }), '1.2.3-test', {
+      stdout,
+      stderr,
+    });
+
+    expect(stdout.text()).toBe('{"role":"assistant","content":"final answer"}\n');
+    expect(stderr.text()).toBe('');
+  });
+
+  it('emits only the final text in text final-message-only mode and skips the resume hint (output B)', async () => {
+    const stdout = writer();
+    const stderr = writer();
+
+    await runPrompt(opts({ finalMessageOnly: true }), '1.2.3-test', { stdout, stderr });
+
+    expect(stdout.text()).toBe('hello world\n');
+    expect(stderr.text()).toBe('');
+  });
+
+  it('reads multiple JSON user messages from stdin and runs a turn for each (input A)', async () => {
+    mocks.session.prompt.mockImplementation(async (command?: string) => {
+      for (const handler of Array.from(mocks.eventHandlers)) {
+        handler(mocks.mainEvent({ type: 'turn.started', turnId: 50, origin: { kind: 'user' } }));
+        handler(mocks.mainEvent({ type: 'assistant.delta', turnId: 50, delta: `echo:${command}` }));
+        handler(mocks.mainEvent({ type: 'turn.ended', turnId: 50, reason: 'completed' }));
+      }
+    });
+    const stdout = writer();
+    const stderr = writer();
+    const stdin = (async function* () {
+      yield JSON.stringify({ role: 'user', content: 'first' });
+      yield JSON.stringify({ role: 'user', content: [{ type: 'text', text: 'second' }] });
+    })();
+
+    await runPrompt(
+      opts({ inputFormat: 'stream-json', outputFormat: 'stream-json', prompt: undefined }),
+      '1.2.3-test',
+      { stdout, stderr, stdin },
+    );
+
+    expect(mocks.session.prompt).toHaveBeenNthCalledWith(1, 'first');
+    expect(mocks.session.prompt).toHaveBeenNthCalledWith(2, 'second');
+    expect(stdout.text()).toBe(
+      [
+        '{"role":"assistant","content":"echo:first"}',
+        '{"role":"assistant","content":"echo:second"}',
+        '{"role":"meta","type":"session.resume_hint","session_id":"ses_prompt","command":"kimi -r ses_prompt","content":"To resume this session: kimi -r ses_prompt"}',
+        '',
+      ].join('\n'),
+    );
+  });
+
+  it('skips blank, malformed, and non-user stdin lines (input A)', async () => {
+    mocks.session.prompt.mockImplementation(async (command?: string) => {
+      for (const handler of Array.from(mocks.eventHandlers)) {
+        handler(mocks.mainEvent({ type: 'turn.started', turnId: 51, origin: { kind: 'user' } }));
+        handler(mocks.mainEvent({ type: 'assistant.delta', turnId: 51, delta: `echo:${command}` }));
+        handler(mocks.mainEvent({ type: 'turn.ended', turnId: 51, reason: 'completed' }));
+      }
+    });
+    const stdout = writer();
+    const stderr = writer();
+    const stdin = (async function* () {
+      yield '';
+      yield 'not json';
+      yield JSON.stringify({ role: 'assistant', content: 'ignore me' });
+      yield JSON.stringify({ role: 'user', content: 'real' });
+    })();
+
+    await runPrompt(
+      opts({ inputFormat: 'stream-json', outputFormat: 'stream-json', prompt: undefined }),
+      '1.2.3-test',
+      { stdout, stderr, stdin },
+    );
+
+    expect(mocks.session.prompt).toHaveBeenCalledTimes(1);
+    expect(mocks.session.prompt).toHaveBeenCalledWith('real');
+    expect(stdout.text()).toBe(
+      [
+        '{"role":"assistant","content":"echo:real"}',
+        '{"role":"meta","type":"session.resume_hint","session_id":"ses_prompt","command":"kimi -r ses_prompt","content":"To resume this session: kimi -r ses_prompt"}',
+        '',
+      ].join('\n'),
+    );
+    expect(stderr.text()).toContain('Ignoring invalid JSON input line: not json');
+    expect(stderr.text()).toContain('Ignoring non-user input message');
+  });
+
+  it('reads a single prompt from stdin with --input-format text (input A)', async () => {
+    const stdout = writer();
+    const stderr = writer();
+    const stdin = (async function* () {
+      yield 'line one';
+      yield 'line two';
+    })();
+
+    await runPrompt(opts({ inputFormat: 'text', prompt: undefined }), '1.2.3-test', {
+      stdout,
+      stderr,
+      stdin,
+    });
+
+    expect(mocks.session.prompt).toHaveBeenCalledWith('line one\nline two');
+    expect(stdout.text()).toBe('• hello world\n\n');
+  });
+
   it('resumes a concrete session without a configured default model', async () => {
     mocks.harnessGetConfig.mockResolvedValueOnce({ providers: {}, telemetry: true });
     mocks.session.getStatus.mockResolvedValueOnce({ permission: 'manual', model: 'saved-model' });
@@ -631,7 +968,7 @@ describe('runPrompt', () => {
     );
   });
 
-  it('restores resumed session permission even when the turn fails', async () => {
+  it('restores resumed session permission and reports a failed turn', async () => {
     mocks.session.prompt.mockImplementationOnce(async () => {
       for (const handler of mocks.eventHandlers) {
         handler(
@@ -647,14 +984,15 @@ describe('runPrompt', () => {
         );
       }
     });
+    const stderr = writer();
 
-    await expect(
-      runPrompt(opts({ session: 'ses_existing' }), '1.2.3-test', {
-        stdout: { write: vi.fn(() => true) },
-        stderr: { write: vi.fn(() => true) },
-      }),
-    ).rejects.toThrow('provider.error: model failed');
+    await runPrompt(opts({ session: 'ses_existing' }), '1.2.3-test', {
+      stdout: { write: vi.fn(() => true) },
+      stderr,
+    });
 
+    expect(stderr.text()).toContain('Error: provider.error: model failed');
+    expect(process.exitCode).toBe(1);
     expect(mocks.session.setPermission).toHaveBeenNthCalledWith(1, 'auto');
     expect(mocks.session.setPermission).toHaveBeenNthCalledWith(2, 'manual');
     expect(mocks.session.setPermission.mock.invocationCallOrder[1]).toBeLessThan(
@@ -826,7 +1164,7 @@ describe('runPrompt', () => {
     expect(mocks.harnessClose).toHaveBeenCalled();
   });
 
-  it('rejects when the turn fails and still closes resources', async () => {
+  it('reports a failed turn to stderr (text mode), sets exit code 1, and still closes resources', async () => {
     mocks.session.prompt.mockImplementationOnce(async () => {
       for (const handler of mocks.eventHandlers) {
         handler(
@@ -842,19 +1180,80 @@ describe('runPrompt', () => {
         );
       }
     });
+    const stderr = writer();
 
-    await expect(
-      runPrompt(opts(), '1.2.3-test', {
-        stdout: { write: vi.fn(() => true) },
-        stderr: { write: vi.fn(() => true) },
-      }),
-    ).rejects.toThrow('provider.error: model failed');
+    await runPrompt(opts(), '1.2.3-test', {
+      stdout: { write: vi.fn(() => true) },
+      stderr,
+    });
 
+    expect(stderr.text()).toContain('Error: provider.error: model failed');
+    expect(process.exitCode).toBe(1);
     expect(mocks.shutdownTelemetry).toHaveBeenCalled();
     expect(mocks.harnessClose).toHaveBeenCalled();
   });
 
-  it('rejects with a friendly message when the provider filters the response', async () => {
+  it('emits a JSON error line on stdout when the turn fails in stream-json mode (output)', async () => {
+    mocks.session.prompt.mockImplementationOnce(async () => {
+      for (const handler of mocks.eventHandlers) {
+        handler(
+          mocks.mainEvent({ type: 'turn.started', turnId: 2, origin: { kind: 'user' } }),
+        );
+        handler(
+          mocks.mainEvent({
+            type: 'turn.ended',
+            turnId: 2,
+            reason: 'failed',
+            error: { code: 'provider.api_error', message: 'model failed', retryable: false },
+          }),
+        );
+      }
+    });
+    const stdout = writer();
+    const stderr = writer();
+
+    await runPrompt(opts({ outputFormat: 'stream-json' }), '1.2.3-test', { stdout, stderr });
+
+    expect(stdout.text()).toBe(
+      [
+        '{"type":"error","code":"provider.api_error","message":"model failed","retryable":false}',
+        '{"role":"meta","type":"session.resume_hint","session_id":"ses_prompt","command":"kimi -r ses_prompt","content":"To resume this session: kimi -r ses_prompt"}',
+        '',
+      ].join('\n'),
+    );
+    expect(stderr.text()).toBe('');
+    expect(process.exitCode).toBe(1);
+  });
+
+  it('maps a retryable provider error to exit code 75', async () => {
+    mocks.session.prompt.mockImplementationOnce(async () => {
+      for (const handler of mocks.eventHandlers) {
+        handler(
+          mocks.mainEvent({ type: 'turn.started', turnId: 2, origin: { kind: 'user' } }),
+        );
+        handler(
+          mocks.mainEvent({
+            type: 'turn.ended',
+            turnId: 2,
+            reason: 'failed',
+            error: { code: 'provider.rate_limit', message: 'slow down', retryable: true },
+          }),
+        );
+      }
+    });
+    const stdout = writer();
+
+    await runPrompt(opts({ outputFormat: 'stream-json' }), '1.2.3-test', {
+      stdout,
+      stderr: writer(),
+    });
+
+    expect(stdout.text()).toContain('"type":"error"');
+    expect(stdout.text()).toContain('"retryable":true');
+    expect(process.exitCode).toBe(75);
+  });
+
+  it('reports a filtered response as a JSON error in stream-json mode', async () => {
     mocks.session.prompt.mockImplementationOnce(async () => {
       for (const handler of mocks.eventHandlers) {
         handler(mocks.mainEvent({ type: 'turn.started', turnId: 2, origin: { kind: 'user' } }));
@@ -867,18 +1266,150 @@ describe('runPrompt', () => {
         );
       }
     });
+    const stdout = writer();
+    const stderr = writer();
 
-    await expect(
-      runPrompt(opts(), '1.2.3-test', {
-        stdout: { write: vi.fn(() => true) },
-        stderr: { write: vi.fn(() => true) },
-      }),
-    ).rejects.toThrow('Provider safety policy blocked the response.');
+    await runPrompt(opts({ outputFormat: 'stream-json' }), '1.2.3-test', { stdout, stderr });
 
+    expect(stdout.text()).toContain(
+      '{"type":"error","code":"provider.filtered","message":"Provider safety policy blocked the response.","retryable":false}',
+    );
+    expect(process.exitCode).toBe(1);
     expect(mocks.shutdownTelemetry).toHaveBeenCalled();
     expect(mocks.harnessClose).toHaveBeenCalled();
   });
 
+  it('reports a filtered response to stderr in text mode and sets exit code 1', async () => {
+    mocks.session.prompt.mockImplementationOnce(async () => {
+      for (const handler of mocks.eventHandlers) {
+        handler(mocks.mainEvent({ type: 'turn.started', turnId: 2, origin: { kind: 'user' } }));
+        handler(
+          mocks.mainEvent({
+            type: 'turn.ended',
+            turnId: 2,
+            reason: 'filtered',
+          }),
+        );
+      }
+    });
+    const stderr = writer();
+
+    await runPrompt(opts(), '1.2.3-test', {
+      stdout: { write: vi.fn(() => true) },
+      stderr,
+    });
+
+    expect(stderr.text()).toContain('Provider safety policy blocked the response.');
+    expect(process.exitCode).toBe(1);
+    expect(mocks.shutdownTelemetry).toHaveBeenCalled();
+    expect(mocks.harnessClose).toHaveBeenCalled();
+  });
+
+  it('treats --quiet as text output with final-message-only and no resume hint', async () => {
+    mocks.session.prompt.mockImplementationOnce(async () => {
+      for (const handler of mocks.eventHandlers) {
+        handler(mocks.mainEvent({ type: 'turn.started', turnId: 60, origin: { kind: 'user' } }));
+        handler(mocks.mainEvent({ type: 'turn.step.started', turnId: 60 }));
+        handler(mocks.mainEvent({ type: 'assistant.delta', turnId: 60, delta: 'first' }));
+        handler(mocks.mainEvent({ type: 'turn.step.started', turnId: 60 }));
+        handler(mocks.mainEvent({ type: 'assistant.delta', turnId: 60, delta: 'final answer' }));
+        handler(mocks.mainEvent({ type: 'turn.ended', turnId: 60, reason: 'completed' }));
+      }
+    });
+    const stdout = writer();
+    const stderr = writer();
+
+    await runPrompt(opts({ quiet: true, outputFormat: undefined }), '1.2.3-test', {
+      stdout,
+      stderr,
+    });
+
+    expect(stdout.text()).toBe('final answer\n');
+    expect(stderr.text()).toBe('');
+  });
+
+  it('waits for active background tasks before exit and emits completions (Tier 2)', async () => {
+    let listCalls = 0;
+    mocks.session.listBackgroundTasks.mockImplementation(async () => {
+      listCalls += 1;
+      return listCalls === 1 ? [{ taskId: 'b1', status: 'running' }] : [];
+    });
+    const fakeClock = {
+      now: () => 0,
+      sleep: vi.fn(async () => {
+        // The task terminates while we wait; the drain subscription emits it.
+        for (const handler of Array.from(mocks.eventHandlers)) {
+          handler(
+            mocks.mainEvent({
+              type: 'background.task.terminated',
+              info: {
+                taskId: 'b1',
+                kind: 'process',
+                status: 'completed',
+                description: 'build',
+                startedAt: 0,
+                endedAt: 1,
+              },
+            }),
+          );
+        }
+      }),
+    };
+    const stdout = writer();
+    const stderr = writer();
+
+    await runPrompt(opts({ outputFormat: 'stream-json' }), '1.2.3-test', {
+      stdout,
+      stderr,
+      clock: fakeClock,
+    });
+
+    expect(fakeClock.sleep).toHaveBeenCalled();
+    expect(mocks.session.listBackgroundTasks).toHaveBeenCalledWith({ activeOnly: true });
+    expect(stdout.text()).toContain(
+      '{"type":"notification","event":"background.task.terminated","taskId":"b1","kind":"process","status":"completed","description":"build"}',
+    );
+  });
+
+  it('skips the background-task wait when keepAliveOnExit is set via env (Tier 2)', async () => {
+    process.env['KIMI_CODE_BACKGROUND_KEEP_ALIVE_ON_EXIT'] = '1';
+    mocks.session.listBackgroundTasks.mockResolvedValue([{ taskId: 'b1', status: 'running' }]);
+    const fakeClock = { now: () => 0, sleep: vi.fn(async () => {}) };
+    try {
+      await runPrompt(opts(), '1.2.3-test', {
+        stdout: { write: vi.fn(() => true) },
+        stderr: { write: vi.fn(() => true) },
+        clock: fakeClock,
+      });
+    } finally {
+      delete process.env['KIMI_CODE_BACKGROUND_KEEP_ALIVE_ON_EXIT'];
+    }
+
+    expect(mocks.session.listBackgroundTasks).not.toHaveBeenCalled();
+    expect(fakeClock.sleep).not.toHaveBeenCalled();
+  });
+
+  it('stops waiting for background tasks after the print-wait ceiling (Tier 2)', async () => {
+    mocks.session.listBackgroundTasks.mockResolvedValue([{ taskId: 'b1', status: 'running' }]);
+    let clockMs = 0;
+    const fakeClock = {
+      now: () => clockMs,
+      sleep: vi.fn(async () => {
+        clockMs += 10_000_000_000; // jump well past the ceiling
+      }),
+    };
+    const stderr = writer();
+
+    await runPrompt(opts(), '1.2.3-test', {
+      stdout: { write: vi.fn(() => true) },
+      stderr,
+      clock: fakeClock,
+    });
+
+    expect(stderr.text()).toContain('Timed out');
+    expect(stderr.text()).toContain('background task');
+  });
+
   it('approval fallback approves if an unexpected approval request reaches SDK', async () => {
     await runPrompt(opts(), '1.2.3-test', {
       stdout: { write: vi.fn(() => true) },
diff --git a/docs/en/reference/kimi-command.md b/docs/en/reference/kimi-command.md
index d14fafa4a..510ebbc65 100644
--- a/docs/en/reference/kimi-command.md
+++ b/docs/en/reference/kimi-command.md
@@ -19,7 +19,10 @@ All flags are optional — run `kimi` directly to enter an interactive session:
 | `--continue` | `-c` | Continue the most recent session in the current working directory, without specifying an ID manually |
 | `--model <model>` | `-m` | Specify a model alias for this launch. When omitted, new sessions use `default_model` from the config file |
 | `--prompt <prompt>` | `-p` | Run a single prompt non-interactively and stream the Assistant output to stdout. This mode does not open the TUI |
-| `--output-format <format>` | | Set the non-interactive output format; supports `text` and `stream-json`. Can only be used with `--prompt`; defaults to `text` |
+| `--output-format <format>` | | Set the non-interactive output format; supports `text` and `stream-json`. Only available in prompt mode; defaults to `text` |
+| `--input-format <format>` | | Read prompts from stdin instead of `--prompt`; supports `text` (all of stdin as one prompt) and `stream-json` (one JSON user message per line, run as successive turns). Implies prompt mode and cannot be combined with `--prompt` |
+| `--final-message-only` | | In prompt mode, emit only the final Assistant message of each turn (thinking, tool calls and notifications are dropped, and the resume hint is suppressed) |
+| `--quiet` | | Shorthand for prompt mode with `--output-format text --final-message-only` |
 | `--yolo` | `-y` | Auto-approve regular tool calls, skipping approval requests |
 | `--auto` | | Start with auto permission mode; tool approvals are handled automatically and the Agent will not ask the user questions |
 | `--plan` | | Start a new session in Plan mode — the AI will prioritize read-only tools for exploration and planning |
@@ -39,7 +42,9 @@ The following combinations are rejected at startup:
 - `--continue` and `--session` are mutually exclusive — both mean "resume a previous session"
 - `--yolo` and `--auto` are mutually exclusive — the two permission modes cannot be combined
 - `--prompt` cannot be used with `--yolo`, `--auto`, or `--plan` — non-interactive mode uses `auto` permission by default
-- `--output-format` can only be used together with `--prompt`
+- `--output-format`, `--input-format` and `--final-message-only` only apply in prompt mode (entered by `--prompt`, `--input-format` or `--quiet`)
+- `--prompt` cannot be combined with `--input-format` — the prompt is read from stdin instead
+- `--quiet` implies `--output-format text`, so combining it with `--output-format stream-json` is rejected
 
 When resuming a session, you can override its saved permission or plan mode by adding `--auto`, `--yolo`, or `--plan`. For example, `kimi --continue --auto` resumes the latest session and switches it to auto permission mode.
 
@@ -116,7 +121,20 @@ When you need to parse output programmatically, use the `stream-json` format —
 kimi -p "List changed files" --output-format stream-json
 ```
 
-In `stream-json` mode, regular replies produce an Assistant message; when the model calls a tool, an Assistant message with `tool_calls` is emitted first, followed by the corresponding Tool message, then subsequent Assistant messages. Thinking content is not written to JSONL; tool progress and "resuming session" notices are still written to stderr.
+In `stream-json` mode, regular replies produce an Assistant message; when the model calls a tool, an Assistant message with `tool_calls` is emitted first, followed by the corresponding Tool message, then subsequent Assistant messages. Thinking content is written as its own line — an Assistant message tagged with `"type":"thinking"` — emitted before the answer it produced. Background-task and cron notifications are emitted as `{"type":"notification", ...}` lines. Tool progress and "resuming session" notices are still written to stderr.
+
+To drive Kimi Code from another program, pair `stream-json` output with `--input-format stream-json` to feed one JSON user message per line over stdin and run each as a turn:
+
+```sh
+printf '%s\n' '{"role":"user","content":"List changed files"}' \
+  | kimi --input-format stream-json --output-format stream-json
+```
+
+Use `--final-message-only` when you only want the final answer of each turn rather than the full stream — for example `kimi -p "..." --output-format stream-json --final-message-only` emits a single Assistant message per turn.
+
+When a turn fails, the error is reported in the active format so the output stays machine-readable: in `stream-json` mode a `{"type":"error","code":"…","message":"…","retryable":…}` line is written to stdout (keeping stdout entirely JSON); in `text` mode it is written to stderr. The process exit code is `0` on success, `75` for a retryable provider error (connection/timeout/rate-limit/5xx), and `1` for any other failure.
+
+Before exiting, prompt mode waits for any still-running background tasks to finish (bounded by `background.print_wait_ceiling_s`, default 3600s), surfacing each task's completion as a notification line in `stream-json` mode. This wait is skipped when `background.keep_alive_on_exit` is set (or `KIMI_CODE_BACKGROUND_KEEP_ALIVE_ON_EXIT=1`), in which case the tasks are left running.
 
 ## Subcommands
 
diff --git a/docs/zh/reference/kimi-command.md b/docs/zh/reference/kimi-command.md
index 187cc48aa..01bf3e3c5 100644
--- a/docs/zh/reference/kimi-command.md
+++ b/docs/zh/reference/kimi-command.md
@@ -19,7 +19,10 @@ kimi <subcommand> [options]
 | `--continue` | `-c` | 继续当前工作目录下最近一次的会话，无需手动指定 ID |
 | `--model <model>` | `-m` | 为本次启动指定模型别名。省略时新会话使用配置文件中的 `default_model` |
 | `--prompt <prompt>` | `-p` | 非交互执行单次 prompt，并把 Assistant 输出流式写到 stdout。该模式不会打开 TUI |
-| `--output-format <format>` | | 设置非交互输出格式，支持 `text` 与 `stream-json`。仅可与 `--prompt` 一起使用，默认 `text` |
+| `--output-format <format>` | | 设置非交互输出格式，支持 `text` 与 `stream-json`。仅在 prompt 模式下可用，默认 `text` |
+| `--input-format <format>` | | 从 stdin 读取 prompt（替代 `--prompt`），支持 `text`（整个 stdin 作为一条 prompt）与 `stream-json`（每行一个 JSON user 消息，依次作为多轮执行）。会进入 prompt 模式，且不能与 `--prompt` 同时使用 |
+| `--final-message-only` | | prompt 模式下只输出每轮最后一条 Assistant 消息（丢弃 thinking、工具调用与 notification，并不再输出恢复会话提示） |
+| `--quiet` | | `--output-format text --final-message-only` 的 prompt 模式简写 |
 | `--yolo` | `-y` | 自动批准普通工具调用，跳过审批请求 |
 | `--auto` | | 以 auto 权限模式启动；工具审批自动处理，Agent 不会向用户提问 |
 | `--plan` | | 以 Plan 模式启动新会话，AI 会优先使用只读工具进行探索和规划 |
@@ -39,7 +42,9 @@ kimi <subcommand> [options]
 - `--continue` 与 `--session` 互斥——两者都表示"恢复历史会话"
 - `--yolo` 和 `--auto` 互斥——两种权限模式互斥
 - `--prompt` 不能与 `--yolo`、`--auto` 或 `--plan` 同时使用——非交互模式固定使用 `auto` 权限
-- `--output-format` 只能与 `--prompt` 一起使用
+- `--output-format`、`--input-format` 与 `--final-message-only` 仅在 prompt 模式下生效（由 `--prompt`、`--input-format` 或 `--quiet` 进入）
+- `--prompt` 不能与 `--input-format` 同时使用——此时 prompt 从 stdin 读取
+- `--quiet` 隐含 `--output-format text`，因此不能与 `--output-format stream-json` 同时使用
 
 恢复会话时，可以通过 `--auto`、`--yolo` 或 `--plan` 覆盖原会话保存的权限或计划模式。例如，`kimi --continue --auto` 会恢复最近会话并切换到 auto 权限模式。
 
@@ -116,7 +121,20 @@ kimi -m kimi-code/kimi-for-coding -p "Explain the latest diff"
 kimi -p "List changed files" --output-format stream-json
 ```
 
-`stream-json` 模式下，普通回复输出 Assistant 消息；模型调用工具时，先输出带 `tool_calls` 的 Assistant 消息，再输出对应的 Tool 消息，最后继续输出后续 Assistant 消息。thinking 内容不会写入 JSONL；工具进度和恢复会话提示仍写到 stderr。
+`stream-json` 模式下，普通回复输出 Assistant 消息；模型调用工具时，先输出带 `tool_calls` 的 Assistant 消息，再输出对应的 Tool 消息，最后继续输出后续 Assistant 消息。thinking 内容会单独成行——一条带 `"type":"thinking"` 标记的 Assistant 消息，排在它所产生的回复之前。后台任务与 cron 通知会输出为 `{"type":"notification", ...}` 行。工具进度和恢复会话提示仍写到 stderr。
+
+需要让其它程序驱动 Kimi Code 时，把 `stream-json` 输出与 `--input-format stream-json` 搭配使用：从 stdin 每行喂一个 JSON user 消息，依次作为多轮执行：
+
+```sh
+printf '%s\n' '{"role":"user","content":"List changed files"}' \
+  | kimi --input-format stream-json --output-format stream-json
+```
+
+只想要每轮最终答案时使用 `--final-message-only`，例如 `kimi -p "..." --output-format stream-json --final-message-only` 每轮只输出一条 Assistant 消息。
+
+turn 失败时，错误会以当前格式上报，保证输出仍可被机器解析：`stream-json` 模式下向 stdout 写一行 `{"type":"error","code":"…","message":"…","retryable":…}`（stdout 保持全 JSON）；`text` 模式下写到 stderr。进程退出码：成功为 `0`，可重试的 provider 错误（连接/超时/限流/5xx）为 `75`，其它失败为 `1`。
+
+退出前，prompt 模式会等待仍在运行的后台任务结束（上限为 `background.print_wait_ceiling_s`，默认 3600s），并在 `stream-json` 模式下把每个任务的完成作为 notification 行输出。当设置了 `background.keep_alive_on_exit`（或 `KIMI_CODE_BACKGROUND_KEEP_ALIVE_ON_EXIT=1`）时跳过等待，后台任务被保留继续运行。
 
 ## 子命令