feat(detection): support Codex Reasoning Level numbered prompt (#616)

src/app/api/worktrees/[id]/prompt-response/route.ts

@@ -14,7 +14,8 @@ import { detectPrompt, type PromptDetectionResult } from '@/lib/detection/prompt
 import { stripAnsi, stripBoxDrawing, buildDetectPromptOptions } from '@/lib/detection/cli-patterns';
 import { sendPromptAnswer } from '@/lib/prompt-answer-sender';
 import { isValidWorktreeId } from '@/lib/security/path-validator';
-import type { PromptType } from '@/types/models';
+import type { PromptType, SubmitMode } from '@/types/models';
+import { isValidSubmitMode } from '@/types/models';
 import { createLogger } from '@/lib/logger';
 
 const logger = createLogger('api/prompt-response');
@@ -26,6 +27,8 @@ interface PromptResponseRequest {
   promptType?: PromptType;
   /** Issue #287: Default option number from client-side detection (fallback when promptCheck fails) */
   defaultOptionNumber?: number;
+  /** Issue #616: Submit mode from client-side detection (fallback when promptCheck fails) */
+  submitMode?: string;
 }
 
 export async function POST(
@@ -41,7 +44,11 @@ export async function POST(
     }
 
     const body: PromptResponseRequest = await req.json();
-    const { answer, cliTool: cliToolParam, promptType: bodyPromptType, defaultOptionNumber: bodyDefaultOptionNumber } = body;
+    const { answer, cliTool: cliToolParam, promptType: bodyPromptType, defaultOptionNumber: bodyDefaultOptionNumber, submitMode: bodySubmitMode } = body;
+
+    // Issue #616: Allowlist validation for submitMode
+    const validSubmitMode: SubmitMode | undefined =
+      isValidSubmitMode(bodySubmitMode) ? bodySubmitMode : undefined;
 
     // Validation
     if (!answer) {
@@ -124,6 +131,7 @@ export async function POST(
         promptData: promptCheck?.promptData,
         fallbackPromptType: bodyPromptType,
         fallbackDefaultOptionNumber: bodyDefaultOptionNumber,
+        fallbackSubmitMode: validSubmitMode,
       });
     } catch (error: unknown) {
       const errorMessage = error instanceof Error ? error.message : 'Unknown error';

src/app/api/worktrees/[id]/respond/route.ts

@@ -6,8 +6,8 @@
 import { NextRequest, NextResponse } from 'next/server';
 import { getDbInstance } from '@/lib/db/db-instance';
 import { getMessageById, updatePromptData, getWorktreeById } from '@/lib/db';
-import { sendKeys } from '@/lib/tmux/tmux';
 import { CLIToolManager } from '@/lib/cli-tools/manager';
+import { sendPromptAnswer } from '@/lib/prompt-answer-sender';
 import { startPolling } from '@/lib/polling/response-poller';
 import { getAnswerInput } from '@/lib/detection/prompt-detector';
 import { broadcastMessage } from '@/lib/ws-server';
@@ -144,20 +144,15 @@ export async function POST(
     // Get session name for the CLI tool
     const sessionName = cliTool.getSessionName(params.id);
 
-    // Send answer to tmux
-    // For Claude prompts, send the answer and then Enter separately
-    // This is because Claude's interactive menu responds immediately to the key press
+    // Send answer to tmux via shared sendPromptAnswer() (Issue #616)
     try {
-      // Send the answer (number or y/n)
-      await sendKeys(sessionName, input, false);
+      await sendPromptAnswer({
+        sessionName,
+        answer: input,
+        cliToolId,
+        promptData: message.promptData,
+      });
       logger.info('sent-answer-to');
-
-      // Wait a moment for the input to be processed
-      await new Promise(resolve => setTimeout(resolve, 100));
-
-      // Send Enter
-      await sendKeys(sessionName, '', true);
-      logger.info('sent-enter-to');
     } catch (error: unknown) {
       const errorMessage = error instanceof Error ? error.message : 'Unknown error';
       return NextResponse.json(

src/lib/detection/prompt-detect-multiple-choice.ts

@@ -1,6 +1,7 @@
 /** Multiple choice prompt detection logic extracted from prompt-detector.ts (Issue #575). */
 
 import type { DetectPromptOptions, PromptDetectionResult } from './types';
+import type { SubmitMode } from '@/types/models';
 
 // ============================================================================
 // Constants
@@ -71,7 +72,18 @@ const COLLAPSED_OUTPUT_PATTERN = /^\s*\[[^\]]*\d+\s+lines?\]/i;
  * When this footer is present, numbered options form an active prompt even if
  * the default cursor marker is missing from the capture output.
  */
-const CONFIRMATION_FOOTER_PATTERN = /press\s+enter\s+to\s+confirm\s+or\s+esc\s+to\s+cancel/i;
+/**
+ * Extended to match both "press enter to confirm" and "press number to confirm" footers.
+ * Issue #616: Codex Reasoning Level UI uses "press number to confirm" instead of "press enter to confirm".
+ */
+const CONFIRMATION_FOOTER_PATTERN = /press\s+(?:enter|number)\s+to\s+confirm/i;
+
+/**
+ * Pattern to detect "press number to confirm" footer specifically.
+ * When matched, the prompt uses answer_only submitMode (no Enter key needed).
+ * Issue #616.
+ */
+const NUMBER_FOOTER_PATTERN = /press\s+number\s+to\s+confirm/i;
 
 /**
  * Maximum number of lines to scan upward from questionEndIndex
@@ -443,6 +455,7 @@ function extractInstructionText(
  * @param instructionText - Instruction text for the prompt block
  * @param output - Original output text (used for rawContent truncation)
  * @param truncateRawContentFn - Function to truncate raw content
+ * @param submitMode - Optional submit mode for the prompt (Issue #616)
  * @returns PromptDetectionResult with isPrompt: true and multiple_choice data
  */
 export function buildMultipleChoiceResult(
@@ -451,6 +464,7 @@ export function buildMultipleChoiceResult(
   instructionText: string | undefined,
   output: string,
   truncateRawContentFn: (content: string) => string,
+  submitMode?: SubmitMode,
 ): PromptDetectionResult {
   return {
     isPrompt: true,
@@ -470,6 +484,7 @@ export function buildMultipleChoiceResult(
       }),
       status: 'pending',
       instructionText,
+      ...(submitMode ? { submitMode } : {}),
     },
     cleanContent: question.trim(),
     rawContent: truncateRawContentFn(output.trim()),  // Issue #235: complete prompt output (truncated) [MF-001]
@@ -523,7 +538,20 @@ export function detectMultipleChoicePrompt(
   // Calculate scan window: last 50 non-trailing-empty lines
   const scanStart = Math.max(0, effectiveEnd - 50);
   const scanWindow = lines.slice(scanStart, effectiveEnd);
-  const hasConfirmationFooter = scanWindow.some((rawLine) => CONFIRMATION_FOOTER_PATTERN.test(rawLine.trim()));
+  // Single-pass footer detection: identify both confirmation footer presence and
+  // specific "press number to confirm" variant in one iteration (Issue #616).
+  let hasConfirmationFooter = false;
+  let hasNumberFooter = false;
+  for (const rawLine of scanWindow) {
+    const trimmed = rawLine.trim();
+    if (!hasConfirmationFooter && CONFIRMATION_FOOTER_PATTERN.test(trimmed)) {
+      hasConfirmationFooter = true;
+      if (NUMBER_FOOTER_PATTERN.test(trimmed)) {
+        hasNumberFooter = true;
+      }
+      break; // Both patterns are subsets of CONFIRMATION_FOOTER; one match suffices
+    }
+  }
 
   // ==========================================================================
   // Pass 1: Check for ❯ indicator existence in scan window
@@ -709,5 +737,10 @@ export function detectMultipleChoicePrompt(
   const question = extractQuestionText(lines, questionEndIndex);
   const instructionText = extractInstructionText(lines, questionEndIndex, effectiveEnd);
 
-  return buildMultipleChoiceResult(question, collectedOptions, instructionText, output, truncateRawContentFn);
+  // Issue #616: Determine submitMode from confirmation footer (detected in single-pass above)
+  const submitMode: SubmitMode | undefined = hasConfirmationFooter
+    ? (hasNumberFooter ? 'answer_only' : 'answer_then_enter')
+    : undefined;
+
+  return buildMultipleChoiceResult(question, collectedOptions, instructionText, output, truncateRawContentFn, submitMode);
 }

src/lib/prompt-answer-sender.ts

@@ -8,12 +8,39 @@
 
 import { sendKeys, sendSpecialKeys } from './tmux/tmux';
 import type { CLIToolType } from './cli-tools/types';
-import type { PromptData, PromptType } from '@/types/models';
+import type { PromptData, PromptType, SubmitMode } from '@/types/models';
+import { isValidSubmitMode } from '@/types/models';
 import { invalidateCache } from './tmux/tmux-capture-cache';
 
 /** Regex pattern to detect checkbox-style multi-select options */
 const CHECKBOX_OPTION_PATTERN = /^\[[ x]\] /;
 
+/**
+ * Resolve the effective SubmitMode from promptData, fallback, and default.
+ * Resolution order: promptData.submitMode -> fallbackSubmitMode -> 'answer_then_enter'.
+ * Invalid values are normalized to 'answer_then_enter' via allowlist validation.
+ *
+ * @returns The resolved SubmitMode, guaranteed to be a valid value.
+ */
+function resolveSubmitMode(params: SendPromptAnswerParams): SubmitMode {
+  const fromPromptData = params.promptData?.type === 'multiple_choice'
+    ? params.promptData.submitMode
+    : undefined;
+  const raw = fromPromptData ?? params.fallbackSubmitMode ?? 'answer_then_enter';
+  return isValidSubmitMode(raw) ? raw : 'answer_then_enter';
+}
+
+/**
+ * Determine whether the Enter key should be suppressed after sending the answer text.
+ * answer_only mode applies only when the prompt is multiple_choice and the answer is numeric.
+ */
+function shouldSuppressEnter(params: SendPromptAnswerParams, submitMode: SubmitMode): boolean {
+  if (submitMode !== 'answer_only') return false;
+  const isMultipleChoice = params.promptData?.type === 'multiple_choice'
+    || params.fallbackPromptType === 'multiple_choice';
+  return isMultipleChoice && /^\d+$/.test(params.answer);
+}
+
 /**
  * Build navigation key array for cursor movement.
  * @param offset - positive = Down, negative = Up
@@ -33,6 +60,8 @@ export interface SendPromptAnswerParams {
   fallbackPromptType?: PromptType;
   /** Fallback default option number from client (only available in route.ts path) */
   fallbackDefaultOptionNumber?: number;
+  /** Fallback submit mode from client (Issue #616) */
+  fallbackSubmitMode?: SubmitMode;
 }
 
 /**
@@ -100,11 +129,16 @@ export async function sendPromptAnswer(params: SendPromptAnswerParams): Promise<
     // Standard CLI prompt: send text + Enter (y/n, Approve?, etc.)
     await sendKeys(sessionName, answer, false);
 
-    // Wait a moment for the input to be processed
-    await new Promise(resolve => setTimeout(resolve, 100));
+    // Issue #616: Resolve submitMode and determine whether to suppress Enter
+    const resolvedSubmitMode = resolveSubmitMode(params);
 
-    // Send Enter
-    await sendKeys(sessionName, '', true);
+    if (!shouldSuppressEnter(params, resolvedSubmitMode)) {
+      // Wait a moment for the input to be processed
+      await new Promise(resolve => setTimeout(resolve, 100));
+
+      // Send Enter
+      await sendKeys(sessionName, '', true);
+    }
   }
 
   // Issue #405: Invalidate cache after sending prompt answer

src/lib/prompt-response-body-builder.ts

@@ -10,7 +10,7 @@
  * re-verification fails. This module eliminates that duplication.
  */
 
-import type { PromptData } from '@/types/models';
+import type { PromptData, SubmitMode } from '@/types/models';
 
 /**
  * Shape of the prompt-response API request body.
@@ -20,6 +20,8 @@ export interface PromptResponseBody {
   cliTool: string;
   promptType?: string;
   defaultOptionNumber?: number;
+  /** Issue #616: Submit mode for multiple choice prompts */
+  submitMode?: SubmitMode;
 }
 
 /**
@@ -49,6 +51,10 @@ export function buildPromptResponseBody(
       if (defaultOption) {
         body.defaultOptionNumber = defaultOption.number;
       }
+      // Issue #616: Include submitMode if present
+      if (promptData.submitMode) {
+        body.submitMode = promptData.submitMode;
+      }
     }
   }
 

src/types/models.ts

@@ -167,13 +167,33 @@ export interface MultipleChoiceOption {
   requiresTextInput?: boolean;
 }
 
+/**
+ * Submit mode for multiple choice prompts.
+ * - 'answer_only': Send only the answer number (no Enter key). Used by Codex CLI "Press number to confirm" UI.
+ * - 'answer_then_enter': Send the answer number followed by Enter key (default behavior).
+ * Issue #616: Codex Reasoning Level selection requires answer_only mode.
+ */
+export type SubmitMode = 'answer_only' | 'answer_then_enter';
+
+/**
+ * Type guard for SubmitMode values.
+ * Validates that a string is a valid SubmitMode ('answer_only' or 'answer_then_enter').
+ * Used for allowlist validation of untrusted input from API requests.
+ * Issue #616.
+ */
+export function isValidSubmitMode(value: unknown): value is SubmitMode {
+  return value === 'answer_only' || value === 'answer_then_enter';
+}
+
 /**
  * Multiple choice prompt data
  */
 export interface MultipleChoicePromptData extends BasePromptData {
   type: 'multiple_choice';
   /** Available options */
   options: MultipleChoiceOption[];
+  /** How to submit the answer: 'answer_only' (no Enter) or 'answer_then_enter' (default). Issue #616. */
+  submitMode?: SubmitMode;
 }
 
 /**