feat: Implement GitHub issue validation management and UI enhancements

- Introduced CRUD operations for GitHub issue validation results, including storage and retrieval. - Added new endpoints for checking validation status, stopping validations, and deleting stored validations. - Enhanced the GitHub routes to support validation management features. - Updated the UI to display validation results and manage validation states for GitHub issues. - Integrated event handling for validation progress and completion notifications.
2026-01-30 14:22:02 +00:00 · 2025-12-23 18:15:30 +01:00
parent 5f0ecc8dd6
commit 6acb751eb3
19 changed files with 1279 additions and 137 deletions
--- a/apps/server/src/index.ts
+++ b/apps/server/src/index.ts
@@ -147,7 +147,7 @@ app.use('/api/templates', createTemplatesRoutes());
 app.use('/api/terminal', createTerminalRoutes());
 app.use('/api/settings', createSettingsRoutes(settingsService));
 app.use('/api/claude', createClaudeRoutes(claudeUsageService));
-app.use('/api/github', createGitHubRoutes());
+app.use('/api/github', createGitHubRoutes(events));
 app.use('/api/context', createContextRoutes());

 // Create HTTP server
--- a/apps/server/src/lib/validation-storage.ts
+++ b/apps/server/src/lib/validation-storage.ts
@@ -0,0 +1,147 @@
+/**
+ * Validation Storage - CRUD operations for GitHub issue validation results
+ *
+ * Stores validation results in .automaker/validations/{issueNumber}/validation.json
+ * Results include the validation verdict, metadata, and timestamp for cache invalidation.
+ */
+
+import * as secureFs from './secure-fs.js';
+import { getValidationsDir, getValidationDir, getValidationPath } from '@automaker/platform';
+import type { StoredValidation } from '@automaker/types';
+
+// Re-export StoredValidation for convenience
+export type { StoredValidation };
+
+/** Number of hours before a validation is considered stale */
+const VALIDATION_CACHE_TTL_HOURS = 24;
+
+/**
+ * Write validation result to storage
+ *
+ * Creates the validation directory if needed and stores the result as JSON.
+ *
+ * @param projectPath - Absolute path to project directory
+ * @param issueNumber - GitHub issue number
+ * @param data - Validation data to store
+ */
+export async function writeValidation(
+  projectPath: string,
+  issueNumber: number,
+  data: StoredValidation
+): Promise<void> {
+  const validationDir = getValidationDir(projectPath, issueNumber);
+  const validationPath = getValidationPath(projectPath, issueNumber);
+
+  // Ensure directory exists
+  await secureFs.mkdir(validationDir, { recursive: true });
+
+  // Write validation result
+  await secureFs.writeFile(validationPath, JSON.stringify(data, null, 2), 'utf-8');
+}
+
+/**
+ * Read validation result from storage
+ *
+ * @param projectPath - Absolute path to project directory
+ * @param issueNumber - GitHub issue number
+ * @returns Stored validation or null if not found
+ */
+export async function readValidation(
+  projectPath: string,
+  issueNumber: number
+): Promise<StoredValidation | null> {
+  try {
+    const validationPath = getValidationPath(projectPath, issueNumber);
+    const content = (await secureFs.readFile(validationPath, 'utf-8')) as string;
+    return JSON.parse(content) as StoredValidation;
+  } catch {
+    // File doesn't exist or can't be read
+    return null;
+  }
+}
+
+/**
+ * Get all stored validations for a project
+ *
+ * @param projectPath - Absolute path to project directory
+ * @returns Array of stored validations
+ */
+export async function getAllValidations(projectPath: string): Promise<StoredValidation[]> {
+  const validations: StoredValidation[] = [];
+  const validationsDir = getValidationsDir(projectPath);
+
+  try {
+    const dirs = await secureFs.readdir(validationsDir, { withFileTypes: true });
+
+    for (const dir of dirs) {
+      if (dir.isDirectory()) {
+        const issueNumber = parseInt(dir.name, 10);
+        if (!isNaN(issueNumber)) {
+          const validation = await readValidation(projectPath, issueNumber);
+          if (validation) {
+            validations.push(validation);
+          }
+        }
+      }
+    }
+  } catch {
+    // Directory doesn't exist
+  }
+
+  // Sort by issue number
+  validations.sort((a, b) => a.issueNumber - b.issueNumber);
+
+  return validations;
+}
+
+/**
+ * Delete a validation from storage
+ *
+ * @param projectPath - Absolute path to project directory
+ * @param issueNumber - GitHub issue number
+ * @returns true if validation was deleted, false if not found
+ */
+export async function deleteValidation(projectPath: string, issueNumber: number): Promise<boolean> {
+  try {
+    const validationDir = getValidationDir(projectPath, issueNumber);
+    await secureFs.rm(validationDir, { recursive: true, force: true });
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+/**
+ * Check if a validation is stale (older than TTL)
+ *
+ * @param validation - Stored validation to check
+ * @returns true if validation is older than 24 hours
+ */
+export function isValidationStale(validation: StoredValidation): boolean {
+  const validatedAt = new Date(validation.validatedAt);
+  const now = new Date();
+  const hoursDiff = (now.getTime() - validatedAt.getTime()) / (1000 * 60 * 60);
+  return hoursDiff > VALIDATION_CACHE_TTL_HOURS;
+}
+
+/**
+ * Get validation with freshness info
+ *
+ * @param projectPath - Absolute path to project directory
+ * @param issueNumber - GitHub issue number
+ * @returns Object with validation and isStale flag, or null if not found
+ */
+export async function getValidationWithFreshness(
+  projectPath: string,
+  issueNumber: number
+): Promise<{ validation: StoredValidation; isStale: boolean } | null> {
+  const validation = await readValidation(projectPath, issueNumber);
+  if (!validation) {
+    return null;
+  }
+
+  return {
+    validation,
+    isStale: isValidationStale(validation),
+  };
+}
--- a/apps/server/src/routes/github/index.ts
+++ b/apps/server/src/routes/github/index.ts
@@ -3,19 +3,44 @@
 */

 import { Router } from 'express';
+import type { EventEmitter } from '../../lib/events.js';
 import { validatePathParams } from '../../middleware/validate-paths.js';
 import { createCheckGitHubRemoteHandler } from './routes/check-github-remote.js';
 import { createListIssuesHandler } from './routes/list-issues.js';
 import { createListPRsHandler } from './routes/list-prs.js';
 import { createValidateIssueHandler } from './routes/validate-issue.js';
+import {
+  createValidationStatusHandler,
+  createValidationStopHandler,
+  createGetValidationsHandler,
+  createDeleteValidationHandler,
+} from './routes/validation-endpoints.js';

-export function createGitHubRoutes(): Router {
+export function createGitHubRoutes(events: EventEmitter): Router {
  const router = Router();

  router.post('/check-remote', validatePathParams('projectPath'), createCheckGitHubRemoteHandler());
  router.post('/issues', validatePathParams('projectPath'), createListIssuesHandler());
  router.post('/prs', validatePathParams('projectPath'), createListPRsHandler());
-  router.post('/validate-issue', validatePathParams('projectPath'), createValidateIssueHandler());
+  router.post(
+    '/validate-issue',
+    validatePathParams('projectPath'),
+    createValidateIssueHandler(events)
+  );
+
+  // Validation management endpoints
+  router.post(
+    '/validation-status',
+    validatePathParams('projectPath'),
+    createValidationStatusHandler()
+  );
+  router.post('/validation-stop', validatePathParams('projectPath'), createValidationStopHandler());
+  router.post('/validations', validatePathParams('projectPath'), createGetValidationsHandler());
+  router.post(
+    '/validation-delete',
+    validatePathParams('projectPath'),
+    createDeleteValidationHandler()
+  );

  return router;
 }
--- a/apps/server/src/routes/github/routes/validate-issue.ts
+++ b/apps/server/src/routes/github/routes/validate-issue.ts
@@ -1,22 +1,31 @@
 /**
- * POST /validate-issue endpoint - Validate a GitHub issue using Claude SDK
+ * POST /validate-issue endpoint - Validate a GitHub issue using Claude SDK (async)
 *
 * Scans the codebase to determine if an issue is valid, invalid, or needs clarification.
+ * Runs asynchronously and emits events for progress and completion.
 */

 import type { Request, Response } from 'express';
 import { query } from '@anthropic-ai/claude-agent-sdk';
-import { createLogger } from '@automaker/utils';
-import type { IssueValidationResult } from '@automaker/types';
+import type { EventEmitter } from '../../../lib/events.js';
+import type { IssueValidationResult, IssueValidationEvent, AgentModel } from '@automaker/types';
 import { createSuggestionsOptions } from '../../../lib/sdk-options.js';
+import { writeValidation } from '../../../lib/validation-storage.js';
 import {
  issueValidationSchema,
  ISSUE_VALIDATION_SYSTEM_PROMPT,
  buildValidationPrompt,
 } from './validation-schema.js';
-import { getErrorMessage, logError } from './common.js';
+import {
+  trySetValidationRunning,
+  clearValidationStatus,
+  getErrorMessage,
+  logError,
+  logger,
+} from './validation-common.js';

-const logger = createLogger('IssueValidation');
+/** Valid model values for validation */
+const VALID_MODELS: readonly AgentModel[] = ['opus', 'sonnet', 'haiku'] as const;

 /**
 * Request body for issue validation
@@ -27,6 +36,148 @@ interface ValidateIssueRequestBody {
  issueTitle: string;
  issueBody: string;
  issueLabels?: string[];
+  /** Model to use for validation (opus, sonnet, haiku) */
+  model?: AgentModel;
+}
+
+/**
+ * Run the validation asynchronously
+ *
+ * Emits events for start, progress, complete, and error.
+ * Stores result on completion.
+ */
+async function runValidation(
+  projectPath: string,
+  issueNumber: number,
+  issueTitle: string,
+  issueBody: string,
+  issueLabels: string[] | undefined,
+  model: AgentModel,
+  events: EventEmitter,
+  abortController: AbortController
+): Promise<void> {
+  // Emit start event
+  const startEvent: IssueValidationEvent = {
+    type: 'issue_validation_start',
+    issueNumber,
+    issueTitle,
+    projectPath,
+  };
+  events.emit('issue-validation:event', startEvent);
+
+  // Set up timeout (6 minutes)
+  const VALIDATION_TIMEOUT_MS = 360000;
+  const timeoutId = setTimeout(() => {
+    logger.warn(`Validation timeout reached after ${VALIDATION_TIMEOUT_MS}ms`);
+    abortController.abort();
+  }, VALIDATION_TIMEOUT_MS);
+
+  try {
+    // Build the prompt
+    const prompt = buildValidationPrompt(issueNumber, issueTitle, issueBody, issueLabels);
+
+    // Create SDK options with structured output and abort controller
+    const options = createSuggestionsOptions({
+      cwd: projectPath,
+      model,
+      systemPrompt: ISSUE_VALIDATION_SYSTEM_PROMPT,
+      abortController,
+      outputFormat: {
+        type: 'json_schema',
+        schema: issueValidationSchema as Record<string, unknown>,
+      },
+    });
+
+    // Execute the query
+    const stream = query({ prompt, options });
+    let validationResult: IssueValidationResult | null = null;
+    let responseText = '';
+
+    for await (const msg of stream) {
+      // Collect assistant text for debugging and emit progress
+      if (msg.type === 'assistant' && msg.message?.content) {
+        for (const block of msg.message.content) {
+          if (block.type === 'text') {
+            responseText += block.text;
+
+            // Emit progress event
+            const progressEvent: IssueValidationEvent = {
+              type: 'issue_validation_progress',
+              issueNumber,
+              content: block.text,
+              projectPath,
+            };
+            events.emit('issue-validation:event', progressEvent);
+          }
+        }
+      }
+
+      // Extract structured output on success
+      if (msg.type === 'result' && msg.subtype === 'success') {
+        const resultMsg = msg as { structured_output?: IssueValidationResult };
+        if (resultMsg.structured_output) {
+          validationResult = resultMsg.structured_output;
+          logger.debug('Received structured output:', validationResult);
+        }
+      }
+
+      // Handle errors
+      if (msg.type === 'result') {
+        const resultMsg = msg as { subtype?: string };
+        if (resultMsg.subtype === 'error_max_structured_output_retries') {
+          logger.error('Failed to produce valid structured output after retries');
+          throw new Error('Could not produce valid validation output');
+        }
+      }
+    }
+
+    // Clear timeout
+    clearTimeout(timeoutId);
+
+    // Require structured output
+    if (!validationResult) {
+      logger.error('No structured output received from Claude SDK');
+      logger.debug('Raw response text:', responseText);
+      throw new Error('Validation failed: no structured output received');
+    }
+
+    logger.info(`Issue #${issueNumber} validation complete: ${validationResult.verdict}`);
+
+    // Store the result
+    await writeValidation(projectPath, issueNumber, {
+      issueNumber,
+      issueTitle,
+      validatedAt: new Date().toISOString(),
+      model,
+      result: validationResult,
+    });
+
+    // Emit completion event
+    const completeEvent: IssueValidationEvent = {
+      type: 'issue_validation_complete',
+      issueNumber,
+      issueTitle,
+      result: validationResult,
+      projectPath,
+    };
+    events.emit('issue-validation:event', completeEvent);
+  } catch (error) {
+    clearTimeout(timeoutId);
+
+    const errorMessage = getErrorMessage(error);
+    logError(error, `Issue #${issueNumber} validation failed`);
+
+    // Emit error event
+    const errorEvent: IssueValidationEvent = {
+      type: 'issue_validation_error',
+      issueNumber,
+      error: errorMessage,
+      projectPath,
+    };
+    events.emit('issue-validation:event', errorEvent);
+
+    throw error;
+  }
 }

 /**
@@ -36,15 +187,19 @@ interface ValidateIssueRequestBody {
 * - Read-only tools (Read, Glob, Grep) for codebase analysis
 * - JSON schema structured output for reliable parsing
 * - System prompt guiding the validation process
+ * - Async execution with event emission
 */
-export function createValidateIssueHandler() {
+export function createValidateIssueHandler(events: EventEmitter) {
  return async (req: Request, res: Response): Promise<void> => {
-    // Declare timeoutId outside try block for proper cleanup
-    let timeoutId: ReturnType<typeof setTimeout> | undefined;
-
    try {
-      const { projectPath, issueNumber, issueTitle, issueBody, issueLabels } =
-        req.body as ValidateIssueRequestBody;
+      const {
+        projectPath,
+        issueNumber,
+        issueTitle,
+        issueBody,
+        issueLabels,
+        model = 'opus',
+      } = req.body as ValidateIssueRequestBody;

      // Validate required fields
      if (!projectPath) {
@@ -69,90 +224,57 @@ export function createValidateIssueHandler() {
        return;
      }

-      logger.info(`Validating issue #${issueNumber}: ${issueTitle}`);
+      // Validate model parameter at runtime
+      if (!VALID_MODELS.includes(model)) {
+        res.status(400).json({
+          success: false,
+          error: `Invalid model. Must be one of: ${VALID_MODELS.join(', ')}`,
+        });
+        return;
+      }

-      // Build the prompt
-      const prompt = buildValidationPrompt(issueNumber, issueTitle, issueBody, issueLabels);
+      logger.info(`Starting async validation for issue #${issueNumber}: ${issueTitle}`);

-      // Create abort controller with 2 minute timeout for validation
+      // Create abort controller and atomically try to claim validation slot
+      // This prevents TOCTOU race conditions
      const abortController = new AbortController();
-      const VALIDATION_TIMEOUT_MS = 360000; // 6 minutes
-      timeoutId = setTimeout(() => {
-        logger.warn(`Validation timeout reached after ${VALIDATION_TIMEOUT_MS}ms`);
-        abortController.abort();
-      }, VALIDATION_TIMEOUT_MS);
-
-      // Create SDK options with structured output and abort controller
-      const options = createSuggestionsOptions({
-        cwd: projectPath,
-        systemPrompt: ISSUE_VALIDATION_SYSTEM_PROMPT,
-        abortController,
-        outputFormat: {
-          type: 'json_schema',
-          schema: issueValidationSchema as Record<string, unknown>,
-        },
-      });
-
-      // Execute the query
-      const stream = query({ prompt, options });
-      let validationResult: IssueValidationResult | null = null;
-      let responseText = '';
-
-      for await (const msg of stream) {
-        // Collect assistant text for debugging/fallback
-        if (msg.type === 'assistant' && msg.message?.content) {
-          for (const block of msg.message.content) {
-            if (block.type === 'text') {
-              responseText += block.text;
-            }
-          }
-        }
-
-        // Extract structured output on success
-        if (msg.type === 'result' && msg.subtype === 'success') {
-          const resultMsg = msg as { structured_output?: IssueValidationResult };
-          if (resultMsg.structured_output) {
-            validationResult = resultMsg.structured_output;
-            logger.debug('Received structured output:', validationResult);
-          }
-        }
-
-        // Handle errors
-        if (msg.type === 'result') {
-          const resultMsg = msg as { subtype?: string };
-          if (resultMsg.subtype === 'error_max_structured_output_retries') {
-            logger.error('Failed to produce valid structured output after retries');
-            throw new Error('Could not produce valid validation output');
-          }
-        }
+      if (!trySetValidationRunning(projectPath, issueNumber, abortController)) {
+        res.json({
+          success: false,
+          error: `Validation is already running for issue #${issueNumber}`,
+        });
+        return;
      }

-      // Require structured output - no fragile fallback parsing
-      if (!validationResult) {
-        logger.error('No structured output received from Claude SDK');
-        logger.debug('Raw response text:', responseText);
-        throw new Error('Validation failed: no structured output received');
-      }
+      // Start validation in background (fire-and-forget)
+      runValidation(
+        projectPath,
+        issueNumber,
+        issueTitle,
+        issueBody,
+        issueLabels,
+        model,
+        events,
+        abortController
+      )
+        .catch((error) => {
+          // Error is already handled inside runValidation (event emitted)
+          logger.debug('Validation error caught in background handler:', error);
+        })
+        .finally(() => {
+          clearValidationStatus(projectPath, issueNumber);
+        });

-      // Clear the timeout since we completed successfully
-      clearTimeout(timeoutId);
-
-      logger.info(`Issue #${issueNumber} validation complete: ${validationResult.verdict}`);
+      // Return immediately
      res.json({
        success: true,
+        message: `Validation started for issue #${issueNumber}`,
        issueNumber,
-        validation: validationResult,
      });
    } catch (error) {
-      // Clear timeout on error as well (if it was set)
-      if (timeoutId) {
-        clearTimeout(timeoutId);
-      }
-
      logError(error, `Issue validation failed`);
      logger.error('Issue validation error:', error);

-      // Check if response already sent
      if (!res.headersSent) {
        res.status(500).json({
          success: false,
--- a/apps/server/src/routes/github/routes/validation-common.ts
+++ b/apps/server/src/routes/github/routes/validation-common.ts
@@ -0,0 +1,174 @@
+/**
+ * Common utilities and state for issue validation routes
+ *
+ * Tracks running validation status per issue to support:
+ * - Checking if a validation is in progress
+ * - Cancelling a running validation
+ * - Preventing duplicate validations for the same issue
+ */
+
+import { createLogger } from '@automaker/utils';
+import { getErrorMessage as getErrorMessageShared, createLogError } from '../../common.js';
+
+const logger = createLogger('IssueValidation');
+
+/**
+ * Status of a validation in progress
+ */
+interface ValidationStatus {
+  isRunning: boolean;
+  abortController: AbortController;
+  startedAt: Date;
+}
+
+/**
+ * Map of issue number to validation status
+ * Key format: `${projectPath}||${issueNumber}` to support multiple projects
+ * Note: Using `||` as delimiter since `:` appears in Windows paths (e.g., C:\)
+ */
+const validationStatusMap = new Map<string, ValidationStatus>();
+
+/** Maximum age for stale validation entries before cleanup (1 hour) */
+const MAX_VALIDATION_AGE_MS = 60 * 60 * 1000;
+
+/**
+ * Create a unique key for a validation
+ * Uses `||` as delimiter since `:` appears in Windows paths
+ */
+function getValidationKey(projectPath: string, issueNumber: number): string {
+  return `${projectPath}||${issueNumber}`;
+}
+
+/**
+ * Check if a validation is currently running for an issue
+ */
+export function isValidationRunning(projectPath: string, issueNumber: number): boolean {
+  const key = getValidationKey(projectPath, issueNumber);
+  const status = validationStatusMap.get(key);
+  return status?.isRunning ?? false;
+}
+
+/**
+ * Get validation status for an issue
+ */
+export function getValidationStatus(
+  projectPath: string,
+  issueNumber: number
+): { isRunning: boolean; startedAt?: Date } | null {
+  const key = getValidationKey(projectPath, issueNumber);
+  const status = validationStatusMap.get(key);
+  if (!status) {
+    return null;
+  }
+  return {
+    isRunning: status.isRunning,
+    startedAt: status.startedAt,
+  };
+}
+
+/**
+ * Get all running validations for a project
+ */
+export function getRunningValidations(projectPath: string): number[] {
+  const runningIssues: number[] = [];
+  const prefix = `${projectPath}||`;
+  for (const [key, status] of validationStatusMap.entries()) {
+    if (status.isRunning && key.startsWith(prefix)) {
+      const issueNumber = parseInt(key.slice(prefix.length), 10);
+      if (!isNaN(issueNumber)) {
+        runningIssues.push(issueNumber);
+      }
+    }
+  }
+  return runningIssues;
+}
+
+/**
+ * Set a validation as running
+ */
+export function setValidationRunning(
+  projectPath: string,
+  issueNumber: number,
+  abortController: AbortController
+): void {
+  const key = getValidationKey(projectPath, issueNumber);
+  validationStatusMap.set(key, {
+    isRunning: true,
+    abortController,
+    startedAt: new Date(),
+  });
+}
+
+/**
+ * Atomically try to set a validation as running (check-and-set)
+ * Prevents TOCTOU race conditions when starting validations
+ *
+ * @returns true if successfully claimed, false if already running
+ */
+export function trySetValidationRunning(
+  projectPath: string,
+  issueNumber: number,
+  abortController: AbortController
+): boolean {
+  const key = getValidationKey(projectPath, issueNumber);
+  if (validationStatusMap.has(key)) {
+    return false; // Already running
+  }
+  validationStatusMap.set(key, {
+    isRunning: true,
+    abortController,
+    startedAt: new Date(),
+  });
+  return true; // Successfully claimed
+}
+
+/**
+ * Cleanup stale validation entries (e.g., from crashed validations)
+ * Should be called periodically to prevent memory leaks
+ */
+export function cleanupStaleValidations(): number {
+  const now = Date.now();
+  let cleanedCount = 0;
+  for (const [key, status] of validationStatusMap.entries()) {
+    if (now - status.startedAt.getTime() > MAX_VALIDATION_AGE_MS) {
+      status.abortController.abort();
+      validationStatusMap.delete(key);
+      cleanedCount++;
+    }
+  }
+  if (cleanedCount > 0) {
+    logger.info(`Cleaned up ${cleanedCount} stale validation entries`);
+  }
+  return cleanedCount;
+}
+
+/**
+ * Clear validation status (call when validation completes or errors)
+ */
+export function clearValidationStatus(projectPath: string, issueNumber: number): void {
+  const key = getValidationKey(projectPath, issueNumber);
+  validationStatusMap.delete(key);
+}
+
+/**
+ * Abort a running validation
+ *
+ * @returns true if validation was aborted, false if not running
+ */
+export function abortValidation(projectPath: string, issueNumber: number): boolean {
+  const key = getValidationKey(projectPath, issueNumber);
+  const status = validationStatusMap.get(key);
+
+  if (!status || !status.isRunning) {
+    return false;
+  }
+
+  status.abortController.abort();
+  validationStatusMap.delete(key);
+  return true;
+}
+
+// Re-export shared utilities
+export { getErrorMessageShared as getErrorMessage };
+export const logError = createLogError(logger);
+export { logger };
--- a/apps/server/src/routes/github/routes/validation-endpoints.ts
+++ b/apps/server/src/routes/github/routes/validation-endpoints.ts
@@ -0,0 +1,190 @@
+/**
+ * Additional validation endpoints for status, stop, and retrieving stored validations
+ */
+
+import type { Request, Response } from 'express';
+import {
+  isValidationRunning,
+  getValidationStatus,
+  getRunningValidations,
+  abortValidation,
+  getErrorMessage,
+  logError,
+  logger,
+} from './validation-common.js';
+import {
+  readValidation,
+  getAllValidations,
+  getValidationWithFreshness,
+  deleteValidation,
+} from '../../../lib/validation-storage.js';
+
+/**
+ * POST /validation-status - Check if validation is running for an issue
+ */
+export function createValidationStatusHandler() {
+  return async (req: Request, res: Response): Promise<void> => {
+    try {
+      const { projectPath, issueNumber } = req.body as {
+        projectPath: string;
+        issueNumber?: number;
+      };
+
+      if (!projectPath) {
+        res.status(400).json({ success: false, error: 'projectPath is required' });
+        return;
+      }
+
+      // If issueNumber provided, check specific issue
+      if (issueNumber !== undefined) {
+        const status = getValidationStatus(projectPath, issueNumber);
+        res.json({
+          success: true,
+          isRunning: status?.isRunning ?? false,
+          startedAt: status?.startedAt?.toISOString(),
+        });
+        return;
+      }
+
+      // Otherwise, return all running validations for the project
+      const runningIssues = getRunningValidations(projectPath);
+      res.json({
+        success: true,
+        runningIssues,
+      });
+    } catch (error) {
+      logError(error, 'Validation status check failed');
+      res.status(500).json({ success: false, error: getErrorMessage(error) });
+    }
+  };
+}
+
+/**
+ * POST /validation-stop - Cancel a running validation
+ */
+export function createValidationStopHandler() {
+  return async (req: Request, res: Response): Promise<void> => {
+    try {
+      const { projectPath, issueNumber } = req.body as {
+        projectPath: string;
+        issueNumber: number;
+      };
+
+      if (!projectPath) {
+        res.status(400).json({ success: false, error: 'projectPath is required' });
+        return;
+      }
+
+      if (!issueNumber || typeof issueNumber !== 'number') {
+        res
+          .status(400)
+          .json({ success: false, error: 'issueNumber is required and must be a number' });
+        return;
+      }
+
+      const wasAborted = abortValidation(projectPath, issueNumber);
+
+      if (wasAborted) {
+        logger.info(`Validation for issue #${issueNumber} was stopped`);
+        res.json({
+          success: true,
+          message: `Validation for issue #${issueNumber} has been stopped`,
+        });
+      } else {
+        res.json({
+          success: false,
+          error: `No validation is running for issue #${issueNumber}`,
+        });
+      }
+    } catch (error) {
+      logError(error, 'Validation stop failed');
+      res.status(500).json({ success: false, error: getErrorMessage(error) });
+    }
+  };
+}
+
+/**
+ * POST /validations - Get stored validations for a project
+ */
+export function createGetValidationsHandler() {
+  return async (req: Request, res: Response): Promise<void> => {
+    try {
+      const { projectPath, issueNumber } = req.body as {
+        projectPath: string;
+        issueNumber?: number;
+      };
+
+      if (!projectPath) {
+        res.status(400).json({ success: false, error: 'projectPath is required' });
+        return;
+      }
+
+      // If issueNumber provided, get specific validation with freshness info
+      if (issueNumber !== undefined) {
+        const result = await getValidationWithFreshness(projectPath, issueNumber);
+
+        if (!result) {
+          res.json({
+            success: true,
+            validation: null,
+          });
+          return;
+        }
+
+        res.json({
+          success: true,
+          validation: result.validation,
+          isStale: result.isStale,
+        });
+        return;
+      }
+
+      // Otherwise, get all validations for the project
+      const validations = await getAllValidations(projectPath);
+
+      res.json({
+        success: true,
+        validations,
+      });
+    } catch (error) {
+      logError(error, 'Get validations failed');
+      res.status(500).json({ success: false, error: getErrorMessage(error) });
+    }
+  };
+}
+
+/**
+ * POST /validation-delete - Delete a stored validation
+ */
+export function createDeleteValidationHandler() {
+  return async (req: Request, res: Response): Promise<void> => {
+    try {
+      const { projectPath, issueNumber } = req.body as {
+        projectPath: string;
+        issueNumber: number;
+      };
+
+      if (!projectPath) {
+        res.status(400).json({ success: false, error: 'projectPath is required' });
+        return;
+      }
+
+      if (!issueNumber || typeof issueNumber !== 'number') {
+        res
+          .status(400)
+          .json({ success: false, error: 'issueNumber is required and must be a number' });
+        return;
+      }
+
+      const deleted = await deleteValidation(projectPath, issueNumber);
+
+      res.json({
+        success: true,
+        deleted,
+      });
+    } catch (error) {
+      logError(error, 'Delete validation failed');
+      res.status(500).json({ success: false, error: getErrorMessage(error) });
+    }
+  };
+}
--- a/apps/ui/src/components/views/github-issues-view.tsx
+++ b/apps/ui/src/components/views/github-issues-view.tsx
@@ -1,4 +1,4 @@
-import { useState, useEffect, useCallback } from 'react';
+import { useState, useEffect, useCallback, useRef } from 'react';
 import {
  CircleDot,
  Loader2,
@@ -10,12 +10,16 @@ import {
  Wand2,
  GitPullRequest,
  User,
+  CheckCircle,
+  Clock,
 } from 'lucide-react';
 import {
  getElectronAPI,
  GitHubIssue,
  IssueValidationResult,
  IssueComplexity,
+  IssueValidationEvent,
+  StoredValidation,
 } from '@/lib/electron';

 /**
@@ -48,10 +52,15 @@ export function GitHubIssuesView() {
  const [refreshing, setRefreshing] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const [selectedIssue, setSelectedIssue] = useState<GitHubIssue | null>(null);
-  const [validating, setValidating] = useState(false);
+  const [validatingIssues, setValidatingIssues] = useState<Set<number>>(new Set());
  const [validationResult, setValidationResult] = useState<IssueValidationResult | null>(null);
  const [showValidationDialog, setShowValidationDialog] = useState(false);
-  const { currentProject } = useAppStore();
+  // Track cached validations for display
+  const [cachedValidations, setCachedValidations] = useState<Map<number, StoredValidation>>(
+    new Map()
+  );
+  const audioRef = useRef<HTMLAudioElement | null>(null);
+  const { currentProject, validationModel, muteDoneSound } = useAppStore();

  const fetchIssues = useCallback(async () => {
    if (!currentProject?.path) {
@@ -85,6 +94,125 @@ export function GitHubIssuesView() {
    fetchIssues();
  }, [fetchIssues]);

+  // Load cached validations on mount
+  useEffect(() => {
+    const loadCachedValidations = async () => {
+      if (!currentProject?.path) return;
+
+      try {
+        const api = getElectronAPI();
+        if (api.github?.getValidations) {
+          const result = await api.github.getValidations(currentProject.path);
+          if (result.success && result.validations) {
+            const map = new Map<number, StoredValidation>();
+            for (const v of result.validations) {
+              map.set(v.issueNumber, v);
+            }
+            setCachedValidations(map);
+          }
+        }
+      } catch (err) {
+        console.error('[GitHubIssuesView] Failed to load cached validations:', err);
+      }
+    };
+
+    loadCachedValidations();
+  }, [currentProject?.path]);
+
+  // Subscribe to validation events
+  useEffect(() => {
+    const api = getElectronAPI();
+    if (!api.github?.onValidationEvent) return;
+
+    const handleValidationEvent = (event: IssueValidationEvent) => {
+      // Only handle events for current project
+      if (event.projectPath !== currentProject?.path) return;
+
+      switch (event.type) {
+        case 'issue_validation_start':
+          setValidatingIssues((prev) => new Set([...prev, event.issueNumber]));
+          break;
+
+        case 'issue_validation_complete':
+          setValidatingIssues((prev) => {
+            const next = new Set(prev);
+            next.delete(event.issueNumber);
+            return next;
+          });
+
+          // Update cached validations (use event.issueTitle to avoid stale closure)
+          setCachedValidations((prev) => {
+            const next = new Map(prev);
+            next.set(event.issueNumber, {
+              issueNumber: event.issueNumber,
+              issueTitle: event.issueTitle,
+              validatedAt: new Date().toISOString(),
+              model: validationModel,
+              result: event.result,
+            });
+            return next;
+          });
+
+          // Show toast notification
+          toast.success(`Issue #${event.issueNumber} validated: ${event.result.verdict}`, {
+            description:
+              event.result.verdict === 'valid'
+                ? 'Issue is ready to be converted to a task'
+                : event.result.verdict === 'invalid'
+                  ? 'Issue may have problems'
+                  : 'Issue needs clarification',
+          });
+
+          // Play audio notification (if not muted)
+          if (!muteDoneSound) {
+            try {
+              if (!audioRef.current) {
+                audioRef.current = new Audio('/sounds/ding.mp3');
+              }
+              audioRef.current.play().catch(() => {
+                // Audio play might fail due to browser restrictions
+              });
+            } catch {
+              // Ignore audio errors
+            }
+          }
+
+          // If validation dialog is open for this issue, update the result
+          if (selectedIssue?.number === event.issueNumber && showValidationDialog) {
+            setValidationResult(event.result);
+          }
+          break;
+
+        case 'issue_validation_error':
+          setValidatingIssues((prev) => {
+            const next = new Set(prev);
+            next.delete(event.issueNumber);
+            return next;
+          });
+          toast.error(`Validation failed for issue #${event.issueNumber}`, {
+            description: event.error,
+          });
+          if (selectedIssue?.number === event.issueNumber && showValidationDialog) {
+            setShowValidationDialog(false);
+          }
+          break;
+      }
+    };
+
+    const unsubscribe = api.github.onValidationEvent(handleValidationEvent);
+    return () => unsubscribe();
+  }, [currentProject?.path, selectedIssue, showValidationDialog, validationModel, muteDoneSound]);
+
+  // Cleanup audio element on unmount to prevent memory leaks
+  useEffect(() => {
+    return () => {
+      if (audioRef.current) {
+        audioRef.current.pause();
+        audioRef.current = null;
+      }
+    };
+  }, []);
+
  const handleRefresh = useCallback(() => {
    setRefreshing(true);
    fetchIssues();
@@ -96,42 +224,83 @@ export function GitHubIssuesView() {
  }, []);

  const handleValidateIssue = useCallback(
-    async (issue: GitHubIssue) => {
+    async (issue: GitHubIssue, showDialog = true) => {
      if (!currentProject?.path) {
        toast.error('No project selected');
        return;
      }

-      setValidating(true);
+      // Check if already validating this issue
+      if (validatingIssues.has(issue.number)) {
+        toast.info(`Validation already in progress for issue #${issue.number}`);
+        return;
+      }
+
+      // Check for cached result - if fresh, show it directly
+      const cached = cachedValidations.get(issue.number);
+      if (cached && showDialog) {
+        // Check if validation is stale (older than 24 hours)
+        const validatedAt = new Date(cached.validatedAt);
+        const hoursSinceValidation = (Date.now() - validatedAt.getTime()) / (1000 * 60 * 60);
+        const isStale = hoursSinceValidation > 24;
+
+        if (!isStale) {
+          // Show cached result directly
+          setValidationResult(cached.result);
+          setShowValidationDialog(true);
+          return;
+        }
+      }
+
+      // Start async validation
      setValidationResult(null);
-      setShowValidationDialog(true);
+      if (showDialog) {
+        setShowValidationDialog(true);
+      }

      try {
        const api = getElectronAPI();
        if (api.github?.validateIssue) {
-          const result = await api.github.validateIssue(currentProject.path, {
-            issueNumber: issue.number,
-            issueTitle: issue.title,
-            issueBody: issue.body || '',
-            issueLabels: issue.labels.map((l) => l.name),
-          });
+          const result = await api.github.validateIssue(
+            currentProject.path,
+            {
+              issueNumber: issue.number,
+              issueTitle: issue.title,
+              issueBody: issue.body || '',
+              issueLabels: issue.labels.map((l) => l.name),
+            },
+            validationModel
+          );

-          if (result.success) {
-            setValidationResult(result.validation);
-          } else {
-            toast.error(result.error || 'Failed to validate issue');
-            setShowValidationDialog(false);
+          if (!result.success) {
+            toast.error(result.error || 'Failed to start validation');
+            if (showDialog) {
+              setShowValidationDialog(false);
+            }
          }
+          // On success, the result will come through the event stream
        }
      } catch (err) {
        console.error('[GitHubIssuesView] Validation error:', err);
        toast.error(err instanceof Error ? err.message : 'Failed to validate issue');
-        setShowValidationDialog(false);
-      } finally {
-        setValidating(false);
+        if (showDialog) {
+          setShowValidationDialog(false);
+        }
      }
    },
-    [currentProject?.path]
+    [currentProject?.path, validatingIssues, cachedValidations, validationModel]
+  );
+
+  // View cached validation result
+  const handleViewCachedValidation = useCallback(
+    (issue: GitHubIssue) => {
+      const cached = cachedValidations.get(issue.number);
+      if (cached) {
+        setValidationResult(cached.result);
+        setShowValidationDialog(true);
+      }
+    },
+    [cachedValidations]
  );

  const handleConvertToTask = useCallback(
@@ -319,19 +488,79 @@ export function GitHubIssuesView() {
              </span>
            </div>
            <div className="flex items-center gap-2 flex-shrink-0">
-              <Button
-                variant="default"
-                size="sm"
-                onClick={() => handleValidateIssue(selectedIssue)}
-                disabled={validating}
-              >
-                {validating ? (
-                  <Loader2 className="h-4 w-4 mr-1 animate-spin" />
-                ) : (
-                  <Wand2 className="h-4 w-4 mr-1" />
-                )}
-                Validate with AI
-              </Button>
+              {(() => {
+                const isValidating = validatingIssues.has(selectedIssue.number);
+                const cached = cachedValidations.get(selectedIssue.number);
+                const isStale =
+                  cached &&
+                  (Date.now() - new Date(cached.validatedAt).getTime()) / (1000 * 60 * 60) > 24;
+
+                if (isValidating) {
+                  return (
+                    <Button variant="default" size="sm" disabled>
+                      <Loader2 className="h-4 w-4 mr-1 animate-spin" />
+                      Validating...
+                    </Button>
+                  );
+                }
+
+                if (cached && !isStale) {
+                  return (
+                    <>
+                      <Button
+                        variant="outline"
+                        size="sm"
+                        onClick={() => handleViewCachedValidation(selectedIssue)}
+                      >
+                        <CheckCircle className="h-4 w-4 mr-1 text-green-500" />
+                        View Result
+                      </Button>
+                      <Button
+                        variant="ghost"
+                        size="sm"
+                        onClick={() => handleValidateIssue(selectedIssue)}
+                        title="Re-validate"
+                      >
+                        <RefreshCw className="h-4 w-4" />
+                      </Button>
+                    </>
+                  );
+                }
+
+                if (cached && isStale) {
+                  return (
+                    <>
+                      <Button
+                        variant="outline"
+                        size="sm"
+                        onClick={() => handleViewCachedValidation(selectedIssue)}
+                      >
+                        <Clock className="h-4 w-4 mr-1 text-yellow-500" />
+                        View (stale)
+                      </Button>
+                      <Button
+                        variant="default"
+                        size="sm"
+                        onClick={() => handleValidateIssue(selectedIssue)}
+                      >
+                        <Wand2 className="h-4 w-4 mr-1" />
+                        Re-validate
+                      </Button>
+                    </>
+                  );
+                }
+
+                return (
+                  <Button
+                    variant="default"
+                    size="sm"
+                    onClick={() => handleValidateIssue(selectedIssue)}
+                  >
+                    <Wand2 className="h-4 w-4 mr-1" />
+                    Validate with AI
+                  </Button>
+                );
+              })()}
              <Button
                variant="outline"
                size="sm"
@@ -484,7 +713,7 @@ export function GitHubIssuesView() {
        onOpenChange={setShowValidationDialog}
        issue={selectedIssue}
        validationResult={validationResult}
-        isValidating={validating}
+        isValidating={selectedIssue ? validatingIssues.has(selectedIssue.number) : false}
        onConvertToTask={handleConvertToTask}
      />
    </div>
--- a/apps/ui/src/components/views/settings-view.tsx
+++ b/apps/ui/src/components/views/settings-view.tsx
@@ -45,6 +45,8 @@ export function SettingsView() {
    setDefaultAIProfileId,
    aiProfiles,
    apiKeys,
+    validationModel,
+    setValidationModel,
  } = useAppStore();

  // Hide usage tracking when using API key (only show for Claude Code CLI users)
@@ -134,6 +136,7 @@ export function SettingsView() {
            defaultRequirePlanApproval={defaultRequirePlanApproval}
            defaultAIProfileId={defaultAIProfileId}
            aiProfiles={aiProfiles}
+            validationModel={validationModel}
            onShowProfilesOnlyChange={setShowProfilesOnly}
            onDefaultSkipTestsChange={setDefaultSkipTests}
            onEnableDependencyBlockingChange={setEnableDependencyBlocking}
@@ -141,6 +144,7 @@ export function SettingsView() {
            onDefaultPlanningModeChange={setDefaultPlanningMode}
            onDefaultRequirePlanApprovalChange={setDefaultRequirePlanApproval}
            onDefaultAIProfileIdChange={setDefaultAIProfileId}
+            onValidationModelChange={setValidationModel}
          />
        );
      case 'danger':
--- a/apps/ui/src/components/views/settings-view/feature-defaults/feature-defaults-section.tsx
+++ b/apps/ui/src/components/views/settings-view/feature-defaults/feature-defaults-section.tsx
@@ -12,6 +12,7 @@ import {
  ScrollText,
  ShieldCheck,
  User,
+  Sparkles,
 } from 'lucide-react';
 import { cn } from '@/lib/utils';
 import {
@@ -22,6 +23,7 @@ import {
  SelectValue,
 } from '@/components/ui/select';
 import type { AIProfile } from '@/store/app-store';
+import type { AgentModel } from '@automaker/types';

 type PlanningMode = 'skip' | 'lite' | 'spec' | 'full';

@@ -34,6 +36,7 @@ interface FeatureDefaultsSectionProps {
  defaultRequirePlanApproval: boolean;
  defaultAIProfileId: string | null;
  aiProfiles: AIProfile[];
+  validationModel: AgentModel;
  onShowProfilesOnlyChange: (value: boolean) => void;
  onDefaultSkipTestsChange: (value: boolean) => void;
  onEnableDependencyBlockingChange: (value: boolean) => void;
@@ -41,6 +44,7 @@ interface FeatureDefaultsSectionProps {
  onDefaultPlanningModeChange: (value: PlanningMode) => void;
  onDefaultRequirePlanApprovalChange: (value: boolean) => void;
  onDefaultAIProfileIdChange: (value: string | null) => void;
+  onValidationModelChange: (value: AgentModel) => void;
 }

 export function FeatureDefaultsSection({
@@ -52,6 +56,7 @@ export function FeatureDefaultsSection({
  defaultRequirePlanApproval,
  defaultAIProfileId,
  aiProfiles,
+  validationModel,
  onShowProfilesOnlyChange,
  onDefaultSkipTestsChange,
  onEnableDependencyBlockingChange,
@@ -59,6 +64,7 @@ export function FeatureDefaultsSection({
  onDefaultPlanningModeChange,
  onDefaultRequirePlanApprovalChange,
  onDefaultAIProfileIdChange,
+  onValidationModelChange,
 }: FeatureDefaultsSectionProps) {
  // Find the selected profile name for display
  const selectedProfile = defaultAIProfileId
@@ -227,6 +233,45 @@ export function FeatureDefaultsSection({
        {/* Separator */}
        <div className="border-t border-border/30" />

+        {/* Issue Validation Model */}
+        <div className="group flex items-start space-x-3 p-3 rounded-xl hover:bg-accent/30 transition-colors duration-200 -mx-3">
+          <div className="w-10 h-10 mt-0.5 rounded-xl flex items-center justify-center shrink-0 bg-purple-500/10">
+            <Sparkles className="w-5 h-5 text-purple-500" />
+          </div>
+          <div className="flex-1 space-y-2">
+            <div className="flex items-center justify-between">
+              <Label className="text-foreground font-medium">Issue Validation Model</Label>
+              <Select
+                value={validationModel}
+                onValueChange={(v: string) => onValidationModelChange(v as AgentModel)}
+              >
+                <SelectTrigger className="w-[140px] h-8" data-testid="validation-model-select">
+                  <SelectValue />
+                </SelectTrigger>
+                <SelectContent>
+                  <SelectItem value="opus">
+                    <span>Opus</span>
+                    <span className="text-[10px] text-muted-foreground ml-1">(Default)</span>
+                  </SelectItem>
+                  <SelectItem value="sonnet">
+                    <span>Sonnet</span>
+                  </SelectItem>
+                  <SelectItem value="haiku">
+                    <span>Haiku</span>
+                  </SelectItem>
+                </SelectContent>
+              </Select>
+            </div>
+            <p className="text-xs text-muted-foreground/80 leading-relaxed">
+              Model used for validating GitHub issues. Opus provides the most thorough analysis,
+              while Haiku is faster and more cost-effective.
+            </p>
+          </div>
+        </div>
+
+        {/* Separator */}
+        <div className="border-t border-border/30" />
+
        {/* Profiles Only Setting */}
        <div className="group flex items-start space-x-3 p-3 rounded-xl hover:bg-accent/30 transition-colors duration-200 -mx-3">
          <Checkbox
--- a/apps/ui/src/hooks/use-settings-migration.ts
+++ b/apps/ui/src/hooks/use-settings-migration.ts
@@ -222,6 +222,7 @@ export async function syncSettingsToServer(): Promise<boolean> {
      defaultAIProfileId: state.defaultAIProfileId,
      muteDoneSound: state.muteDoneSound,
      enhancementModel: state.enhancementModel,
+      validationModel: state.validationModel,
      keyboardShortcuts: state.keyboardShortcuts,
      aiProfiles: state.aiProfiles,
      projects: state.projects,
--- a/apps/ui/src/lib/electron.ts
+++ b/apps/ui/src/lib/electron.ts
@@ -8,6 +8,9 @@ import type {
  IssueValidationInput,
  IssueValidationResult,
  IssueValidationResponse,
+  IssueValidationEvent,
+  StoredValidation,
+  AgentModel,
 } from '@automaker/types';
 import { getJSON, setJSON, removeItem } from './storage';

@@ -19,6 +22,8 @@ export type {
  IssueValidationInput,
  IssueValidationResult,
  IssueValidationResponse,
+  IssueValidationEvent,
+  StoredValidation,
 };

 export interface FileEntry {
@@ -189,10 +194,41 @@ export interface GitHubAPI {
    mergedPRs?: GitHubPR[];
    error?: string;
  }>;
+  /** Start async validation of a GitHub issue */
  validateIssue: (
    projectPath: string,
-    issue: IssueValidationInput
-  ) => Promise<IssueValidationResponse | { success: false; error: string }>;
+    issue: IssueValidationInput,
+    model?: AgentModel
+  ) => Promise<{ success: boolean; message?: string; issueNumber?: number; error?: string }>;
+  /** Check validation status for an issue or all issues */
+  getValidationStatus: (
+    projectPath: string,
+    issueNumber?: number
+  ) => Promise<{
+    success: boolean;
+    isRunning?: boolean;
+    startedAt?: string;
+    runningIssues?: number[];
+    error?: string;
+  }>;
+  /** Stop a running validation */
+  stopValidation: (
+    projectPath: string,
+    issueNumber: number
+  ) => Promise<{ success: boolean; message?: string; error?: string }>;
+  /** Get stored validations for a project */
+  getValidations: (
+    projectPath: string,
+    issueNumber?: number
+  ) => Promise<{
+    success: boolean;
+    validation?: StoredValidation | null;
+    validations?: StoredValidation[];
+    isStale?: boolean;
+    error?: string;
+  }>;
+  /** Subscribe to validation events */
+  onValidationEvent: (callback: (event: IssueValidationEvent) => void) => () => void;
 }

 // Feature Suggestions types
@@ -2640,6 +2676,8 @@ function createMockRunningAgentsAPI(): RunningAgentsAPI {
 }

 // Mock GitHub API implementation
+let mockValidationCallbacks: ((event: IssueValidationEvent) => void)[] = [];
+
 function createMockGitHubAPI(): GitHubAPI {
  return {
    checkRemote: async (projectPath: string) => {
@@ -2668,20 +2706,71 @@ function createMockGitHubAPI(): GitHubAPI {
        mergedPRs: [],
      };
    },
-    validateIssue: async (projectPath: string, issue: IssueValidationInput) => {
-      console.log('[Mock] Validating GitHub issue:', { projectPath, issue });
-      // Return a mock validation result
+    validateIssue: async (projectPath: string, issue: IssueValidationInput, model?: AgentModel) => {
+      console.log('[Mock] Starting async validation:', { projectPath, issue, model });
+
+      // Simulate async validation in background
+      setTimeout(() => {
+        mockValidationCallbacks.forEach((cb) =>
+          cb({
+            type: 'issue_validation_start',
+            issueNumber: issue.issueNumber,
+            issueTitle: issue.issueTitle,
+            projectPath,
+          })
+        );
+
+        setTimeout(() => {
+          mockValidationCallbacks.forEach((cb) =>
+            cb({
+              type: 'issue_validation_complete',
+              issueNumber: issue.issueNumber,
+              result: {
+                verdict: 'valid' as const,
+                confidence: 'medium' as const,
+                reasoning:
+                  'This is a mock validation. In production, Claude SDK would analyze the codebase to validate this issue.',
+                relatedFiles: ['src/components/example.tsx'],
+                estimatedComplexity: 'moderate' as const,
+              },
+              projectPath,
+            })
+          );
+        }, 2000);
+      }, 100);
+
      return {
-        success: true as const,
+        success: true,
+        message: `Validation started for issue #${issue.issueNumber}`,
        issueNumber: issue.issueNumber,
-        validation: {
-          verdict: 'valid' as const,
-          confidence: 'medium' as const,
-          reasoning:
-            'This is a mock validation. In production, Claude SDK would analyze the codebase to validate this issue.',
-          relatedFiles: ['src/components/example.tsx'],
-          estimatedComplexity: 'moderate' as const,
-        },
+      };
+    },
+    getValidationStatus: async (projectPath: string, issueNumber?: number) => {
+      console.log('[Mock] Getting validation status:', { projectPath, issueNumber });
+      return {
+        success: true,
+        isRunning: false,
+        runningIssues: [],
+      };
+    },
+    stopValidation: async (projectPath: string, issueNumber: number) => {
+      console.log('[Mock] Stopping validation:', { projectPath, issueNumber });
+      return {
+        success: true,
+        message: `Validation for issue #${issueNumber} stopped`,
+      };
+    },
+    getValidations: async (projectPath: string, issueNumber?: number) => {
+      console.log('[Mock] Getting validations:', { projectPath, issueNumber });
+      return {
+        success: true,
+        validations: [],
+      };
+    },
+    onValidationEvent: (callback: (event: IssueValidationEvent) => void) => {
+      mockValidationCallbacks.push(callback);
+      return () => {
+        mockValidationCallbacks = mockValidationCallbacks.filter((cb) => cb !== callback);
      };
    },
  };
--- a/apps/ui/src/lib/http-api-client.ts
+++ b/apps/ui/src/lib/http-api-client.ts
@@ -25,6 +25,7 @@ import type {
  GitHubIssue,
  GitHubPR,
  IssueValidationInput,
+  IssueValidationEvent,
 } from './electron';
 import type { Message, SessionListItem } from '@/types/electron';
 import type { Feature, ClaudeUsageResponse } from '@/store/app-store';
@@ -52,7 +53,8 @@ type EventType =
  | 'agent:stream'
  | 'auto-mode:event'
  | 'suggestions:event'
-  | 'spec-regeneration:event';
+  | 'spec-regeneration:event'
+  | 'issue-validation:event';

 type EventCallback = (payload: unknown) => void;

@@ -752,8 +754,16 @@ export class HttpApiClient implements ElectronAPI {
    checkRemote: (projectPath: string) => this.post('/api/github/check-remote', { projectPath }),
    listIssues: (projectPath: string) => this.post('/api/github/issues', { projectPath }),
    listPRs: (projectPath: string) => this.post('/api/github/prs', { projectPath }),
-    validateIssue: (projectPath: string, issue: IssueValidationInput) =>
-      this.post('/api/github/validate-issue', { projectPath, ...issue }),
+    validateIssue: (projectPath: string, issue: IssueValidationInput, model?: string) =>
+      this.post('/api/github/validate-issue', { projectPath, ...issue, model }),
+    getValidationStatus: (projectPath: string, issueNumber?: number) =>
+      this.post('/api/github/validation-status', { projectPath, issueNumber }),
+    stopValidation: (projectPath: string, issueNumber: number) =>
+      this.post('/api/github/validation-stop', { projectPath, issueNumber }),
+    getValidations: (projectPath: string, issueNumber?: number) =>
+      this.post('/api/github/validations', { projectPath, issueNumber }),
+    onValidationEvent: (callback: (event: IssueValidationEvent) => void) =>
+      this.subscribeToEvent('issue-validation:event', callback as EventCallback),
  };

  // Workspace API
--- a/apps/ui/src/store/app-store.ts
+++ b/apps/ui/src/store/app-store.ts
@@ -475,6 +475,9 @@ export interface AppState {
  // Enhancement Model Settings
  enhancementModel: AgentModel; // Model used for feature enhancement (default: sonnet)

+  // Validation Model Settings
+  validationModel: AgentModel; // Model used for GitHub issue validation (default: opus)
+
  // Project Analysis
  projectAnalysis: ProjectAnalysis | null;
  isAnalyzing: boolean;
@@ -745,6 +748,9 @@ export interface AppActions {
  // Enhancement Model actions
  setEnhancementModel: (model: AgentModel) => void;

+  // Validation Model actions
+  setValidationModel: (model: AgentModel) => void;
+
  // AI Profile actions
  addAIProfile: (profile: Omit<AIProfile, 'id'>) => void;
  updateAIProfile: (id: string, updates: Partial<AIProfile>) => void;
@@ -915,6 +921,7 @@ const initialState: AppState = {
  keyboardShortcuts: DEFAULT_KEYBOARD_SHORTCUTS, // Default keyboard shortcuts
  muteDoneSound: false, // Default to sound enabled (not muted)
  enhancementModel: 'sonnet', // Default to sonnet for feature enhancement
+  validationModel: 'opus', // Default to opus for GitHub issue validation
  aiProfiles: DEFAULT_AI_PROFILES,
  projectAnalysis: null,
  isAnalyzing: false,
@@ -1537,6 +1544,9 @@ export const useAppStore = create<AppState & AppActions>()(
      // Enhancement Model actions
      setEnhancementModel: (model) => set({ enhancementModel: model }),

+      // Validation Model actions
+      setValidationModel: (model) => set({ validationModel: model }),
+
      // AI Profile actions
      addAIProfile: (profile) => {
        const id = `profile-${Date.now()}-${Math.random().toString(36).substr(2, 9)}`;
@@ -2679,6 +2689,7 @@ export const useAppStore = create<AppState & AppActions>()(
          keyboardShortcuts: state.keyboardShortcuts,
          muteDoneSound: state.muteDoneSound,
          enhancementModel: state.enhancementModel,
+          validationModel: state.validationModel,
          // Profiles and sessions
          aiProfiles: state.aiProfiles,
          chatSessions: state.chatSessions,
--- a/libs/platform/src/index.ts
+++ b/libs/platform/src/index.ts
@@ -13,6 +13,9 @@ export {
  getImagesDir,
  getContextDir,
  getWorktreesDir,
+  getValidationsDir,
+  getValidationDir,
+  getValidationPath,
  getAppSpecPath,
  getBranchTrackingPath,
  ensureAutomakerDir,
--- a/libs/platform/src/paths.ts
+++ b/libs/platform/src/paths.ts
@@ -111,6 +111,44 @@ export function getWorktreesDir(projectPath: string): string {
  return path.join(getAutomakerDir(projectPath), 'worktrees');
 }

+/**
+ * Get the validations directory for a project
+ *
+ * Stores GitHub issue validation results, organized by issue number.
+ *
+ * @param projectPath - Absolute path to project directory
+ * @returns Absolute path to {projectPath}/.automaker/validations
+ */
+export function getValidationsDir(projectPath: string): string {
+  return path.join(getAutomakerDir(projectPath), 'validations');
+}
+
+/**
+ * Get the directory for a specific issue validation
+ *
+ * Contains validation result and metadata for a GitHub issue.
+ *
+ * @param projectPath - Absolute path to project directory
+ * @param issueNumber - GitHub issue number
+ * @returns Absolute path to {projectPath}/.automaker/validations/{issueNumber}
+ */
+export function getValidationDir(projectPath: string, issueNumber: number): string {
+  return path.join(getValidationsDir(projectPath), String(issueNumber));
+}
+
+/**
+ * Get the validation result file path for a GitHub issue
+ *
+ * Stores the JSON validation result including verdict, analysis, and metadata.
+ *
+ * @param projectPath - Absolute path to project directory
+ * @param issueNumber - GitHub issue number
+ * @returns Absolute path to {projectPath}/.automaker/validations/{issueNumber}/validation.json
+ */
+export function getValidationPath(projectPath: string, issueNumber: number): string {
+  return path.join(getValidationDir(projectPath, issueNumber), 'validation.json');
+}
+
 /**
 * Get the app spec file path for a project
 *
--- a/libs/types/src/event.ts
+++ b/libs/types/src/event.ts
@@ -24,6 +24,7 @@ export type EventType =
  | 'project:analysis-completed'
  | 'project:analysis-error'
  | 'suggestions:event'
-  | 'spec-regeneration:event';
+  | 'spec-regeneration:event'
+  | 'issue-validation:event';

 export type EventCallback = (type: EventType, payload: unknown) => void;
--- a/libs/types/src/index.ts
+++ b/libs/types/src/index.ts
@@ -92,4 +92,6 @@ export type {
  IssueValidationResult,
  IssueValidationResponse,
  IssueValidationErrorResponse,
+  IssueValidationEvent,
+  StoredValidation,
 } from './issue-validation.js';
--- a/libs/types/src/issue-validation.ts
+++ b/libs/types/src/issue-validation.ts
@@ -4,6 +4,8 @@
 * Types for validating GitHub issues against the codebase using Claude SDK.
 */

+import type { AgentModel } from './model.js';
+
 /**
 * Verdict from issue validation
 */
@@ -76,3 +78,49 @@ export interface IssueValidationErrorResponse {
  success: false;
  error: string;
 }
+
+/**
+ * Events emitted during async issue validation
+ */
+export type IssueValidationEvent =
+  | {
+      type: 'issue_validation_start';
+      issueNumber: number;
+      issueTitle: string;
+      projectPath: string;
+    }
+  | {
+      type: 'issue_validation_progress';
+      issueNumber: number;
+      content: string;
+      projectPath: string;
+    }
+  | {
+      type: 'issue_validation_complete';
+      issueNumber: number;
+      issueTitle: string;
+      result: IssueValidationResult;
+      projectPath: string;
+    }
+  | {
+      type: 'issue_validation_error';
+      issueNumber: number;
+      error: string;
+      projectPath: string;
+    };
+
+/**
+ * Stored validation data with metadata for cache
+ */
+export interface StoredValidation {
+  /** GitHub issue number */
+  issueNumber: number;
+  /** Issue title at time of validation */
+  issueTitle: string;
+  /** ISO timestamp when validation was performed */
+  validatedAt: string;
+  /** Model used for validation (opus, sonnet, haiku) */
+  model: AgentModel;
+  /** The validation result */
+  result: IssueValidationResult;
+}
--- a/libs/types/src/settings.ts
+++ b/libs/types/src/settings.ts
@@ -261,6 +261,8 @@ export interface GlobalSettings {
  // AI Model Selection
  /** Which model to use for feature name/description enhancement */
  enhancementModel: AgentModel;
+  /** Which model to use for GitHub issue validation */
+  validationModel: AgentModel;

  // Input Configuration
  /** User's keyboard shortcut bindings */
@@ -437,6 +439,7 @@ export const DEFAULT_GLOBAL_SETTINGS: GlobalSettings = {
  defaultAIProfileId: null,
  muteDoneSound: false,
  enhancementModel: 'sonnet',
+  validationModel: 'opus',
  keyboardShortcuts: DEFAULT_KEYBOARD_SHORTCUTS,
  aiProfiles: [],
  projects: [],