diff --git a/src/cliproxy/cliproxy-executor.ts b/src/cliproxy/cliproxy-executor.ts
index df768b0d..e0c245a8 100644
--- a/src/cliproxy/cliproxy-executor.ts
+++ b/src/cliproxy/cliproxy-executor.ts
@@ -26,8 +26,8 @@ import {
 } from './config-generator';
 import { isAuthenticated } from './auth-handler';
 import { CLIProxyProvider, ExecutorConfig } from './types';
-import { configureProviderModel } from './model-config';
-import { supportsModelConfig } from './model-catalog';
+import { configureProviderModel, getCurrentModel } from './model-config';
+import { supportsModelConfig, isModelBroken, getModelIssueUrl, findModel } from './model-catalog';
 
 /** Default executor configuration */
 const DEFAULT_CONFIG: ExecutorConfig = {
@@ -170,7 +170,24 @@ export async function execClaudeWithCLIProxy(
     await configureProviderModel(provider, false); // false = only if not configured
   }
 
-  // 5. Ensure user settings file exists (creates from defaults if not)
+  // 5. Check for known broken models and warn user
+  const currentModel = getCurrentModel(provider);
+  if (currentModel && isModelBroken(provider, currentModel)) {
+    const modelEntry = findModel(provider, currentModel);
+    const issueUrl = getModelIssueUrl(provider, currentModel);
+    console.error('');
+    console.error(
+      `[!] Warning: ${modelEntry?.name || currentModel} has known issues with Claude Code`
+    );
+    console.error('    Tool calls will fail. Use "gemini-3-pro-preview" instead.');
+    if (issueUrl) {
+      console.error(`    Tracking: ${issueUrl}`);
+    }
+    console.error(`    Run "ccs ${provider} --config" to change model.`);
+    console.error('');
+  }
+
+  // 6. Ensure user settings file exists (creates from defaults if not)
   ensureProviderSettings(provider);
 
   // 6. Generate config file
diff --git a/src/cliproxy/model-catalog.ts b/src/cliproxy/model-catalog.ts
index 5c609330..767fdfaf 100644
--- a/src/cliproxy/model-catalog.ts
+++ b/src/cliproxy/model-catalog.ts
@@ -19,6 +19,10 @@ export interface ModelEntry {
   tier?: 'free' | 'paid';
   /** Optional description for the model */
   description?: string;
+  /** Model has known issues - show warning when selected */
+  broken?: boolean;
+  /** Issue URL for broken models */
+  issueUrl?: string;
 }
 
 /**
@@ -46,16 +50,22 @@ export const MODEL_CATALOG: Partial<Record<CLIProxyProvider, ProviderCatalog>> =
         id: 'gemini-claude-opus-4-5-thinking',
         name: 'Claude Opus 4.5 Thinking',
         description: 'Most capable, extended thinking',
+        broken: true,
+        issueUrl: 'https://github.com/router-for-me/CLIProxyAPI/issues/415',
       },
       {
         id: 'gemini-claude-sonnet-4-5-thinking',
         name: 'Claude Sonnet 4.5 Thinking',
         description: 'Balanced with extended thinking',
+        broken: true,
+        issueUrl: 'https://github.com/router-for-me/CLIProxyAPI/issues/415',
       },
       {
         id: 'gemini-claude-sonnet-4-5',
         name: 'Claude Sonnet 4.5',
         description: 'Fast and capable',
+        broken: true,
+        issueUrl: 'https://github.com/router-for-me/CLIProxyAPI/issues/415',
       },
       {
         id: 'gemini-3-pro-preview',
@@ -107,3 +117,19 @@ export function findModel(provider: CLIProxyProvider, modelId: string): ModelEnt
   if (!catalog) return undefined;
   return catalog.models.find((m) => m.id === modelId);
 }
+
+/**
+ * Check if model has known issues
+ */
+export function isModelBroken(provider: CLIProxyProvider, modelId: string): boolean {
+  const model = findModel(provider, modelId);
+  return model?.broken === true;
+}
+
+/**
+ * Get issue URL for broken model
+ */
+export function getModelIssueUrl(provider: CLIProxyProvider, modelId: string): string | undefined {
+  const model = findModel(provider, modelId);
+  return model?.issueUrl;
+}
diff --git a/src/cliproxy/model-config.ts b/src/cliproxy/model-config.ts
index b5b4311c..0e9c9190 100644
--- a/src/cliproxy/model-config.ts
+++ b/src/cliproxy/model-config.ts
@@ -45,7 +45,8 @@ export function getCurrentModel(provider: CLIProxyProvider): string | undefined
 function formatModelOption(model: ModelEntry): string {
   // Tier badge: clarify that "paid" means paid Google account (not free tier)
   const tierBadge = model.tier === 'paid' ? color(' [Paid Tier]', 'warning') : '';
-  return `${model.name}${tierBadge}`;
+  const brokenBadge = model.broken ? color(' [BROKEN]', 'error') : '';
+  return `${model.name}${tierBadge}${brokenBadge}`;
 }
 
 /**
@@ -55,8 +56,9 @@ function formatModelDetailed(model: ModelEntry, isCurrent: boolean): string {
   const marker = isCurrent ? color('>', 'success') : ' ';
   const name = isCurrent ? bold(model.name) : model.name;
   const tierBadge = model.tier === 'paid' ? color(' [Paid Tier]', 'warning') : '';
+  const brokenBadge = model.broken ? color(' [BROKEN]', 'error') : '';
   const desc = model.description ? dim(` - ${model.description}`) : '';
-  return `  ${marker} ${name}${tierBadge}${desc}`;
+  return `  ${marker} ${name}${tierBadge}${brokenBadge}${desc}`;
 }
 
 /**