diff --git a/conf/custom_models.json b/conf/custom_models.json
index 2b9f7c7..2a3bcf3 100644
--- a/conf/custom_models.json
+++ b/conf/custom_models.json
@@ -7,7 +7,7 @@
       "Self-hosted APIs - Any OpenAI-compatible endpoint"
     ],
     "documentation": "https://github.com/BeehiveInnovations/zen-mcp-server/blob/main/docs/custom_models.md",
-    "usage": "Models can be accessed via aliases (e.g., 'opus', 'local-llama') or full names (e.g., 'anthropic/claude-3-opus', 'llama3.2')",
+    "usage": "Models can be accessed via aliases (e.g., 'opus', 'local-llama') or full names (e.g., 'anthropic/claude-opus-4', 'llama3.2')",
     "instructions": [
       "Add new models by copying an existing entry and modifying it",
       "Aliases are case-insensitive and should be unique across all models",
@@ -15,11 +15,11 @@
       "Set supports_* flags based on the model's actual capabilities",
       "Set is_custom=true for models that should ONLY work with custom endpoints (Ollama, vLLM, etc.)",
       "Models not listed here will use generic defaults (32K context window, basic features)",
-      "For OpenRouter models: Use official OpenRouter model names (e.g., 'anthropic/claude-3-opus')",
+      "For OpenRouter models: Use official OpenRouter model names (e.g., 'anthropic/claude-opus-4')",
       "For local/custom models: Use model names as they appear in your API (e.g., 'llama3.2', 'gpt-3.5-turbo')"
     ],
     "field_descriptions": {
-      "model_name": "The model identifier - OpenRouter format (e.g., 'anthropic/claude-3-opus') or custom model name (e.g., 'llama3.2')",
+      "model_name": "The model identifier - OpenRouter format (e.g., 'anthropic/claude-opus-4') or custom model name (e.g., 'llama3.2')",
       "aliases": "Array of short names users can type instead of the full model name",
       "context_window": "Total number of tokens the model can process (input + output combined)",
       "supports_extended_thinking": "Whether the model supports extended reasoning tokens (currently none do via OpenRouter or custom APIs)",
@@ -49,29 +49,29 @@
   },
   "models": [
     {
-      "model_name": "anthropic/claude-3-opus",
-      "aliases": ["opus", "claude-opus", "claude3-opus", "claude-3-opus"],
+      "model_name": "anthropic/claude-opus-4",
+      "aliases": ["opus", "claude-opus", "claude4-opus", "claude-4-opus"],
       "context_window": 200000,
       "supports_extended_thinking": false,
       "supports_json_mode": false,
       "supports_function_calling": false,
       "supports_images": true,
       "max_image_size_mb": 5.0,
-      "description": "Claude 3 Opus - Most capable Claude model with vision"
+      "description": "Claude 4 Opus - Most capable Claude model with vision"
     },
     {
-      "model_name": "anthropic/claude-3-sonnet",
-      "aliases": ["sonnet", "claude-sonnet", "claude3-sonnet", "claude-3-sonnet", "claude"],
+      "model_name": "anthropic/claude-sonnet-4",
+      "aliases": ["sonnet", "claude-sonnet", "claude4-sonnet", "claude-4-sonnet", "claude"],
       "context_window": 200000,
       "supports_extended_thinking": false,
       "supports_json_mode": false,
       "supports_function_calling": false,
       "supports_images": true,
       "max_image_size_mb": 5.0,
-      "description": "Claude 3 Sonnet - Balanced performance with vision"
+      "description": "Claude 4 Sonnet - Balanced performance with vision"
     },
     {
-      "model_name": "anthropic/claude-3-haiku",
+      "model_name": "anthropic/claude-3.5-haiku",
       "aliases": ["haiku", "claude-haiku", "claude3-haiku", "claude-3-haiku"],
       "context_window": 200000,
       "supports_extended_thinking": false,
diff --git a/docs/adding_providers.md b/docs/adding_providers.md
index f3f3a4e..c93574f 100644
--- a/docs/adding_providers.md
+++ b/docs/adding_providers.md
@@ -690,7 +690,7 @@ When a user requests a model (e.g., "pro", "o3", "example-large-v1"), the system
 2. OpenAI skips (Gemini already handled it)
 3. OpenRouter never sees it
 
-### Example: Model "claude-3-opus" 
+### Example: Model "claude-4-opus" 
 
 1. **Gemini provider** checks: NO, not my model → skip
 2. **OpenAI provider** checks: NO, not my model → skip  
diff --git a/docs/custom_models.md b/docs/custom_models.md
index 8094675..45f6967 100644
--- a/docs/custom_models.md
+++ b/docs/custom_models.md
@@ -41,9 +41,9 @@ The server uses `conf/custom_models.json` to map convenient aliases to both Open
 
 | Alias | Maps to OpenRouter Model |
 |-------|-------------------------|
-| `opus` | `anthropic/claude-3-opus` |
-| `sonnet`, `claude` | `anthropic/claude-3-sonnet` |
-| `haiku` | `anthropic/claude-3-haiku` |
+| `opus` | `anthropic/claude-opus-4` |
+| `sonnet`, `claude` | `anthropic/claude-sonnet-4` |
+| `haiku` | `anthropic/claude-3.5-haiku` |
 | `gpt4o`, `4o` | `openai/gpt-4o` |
 | `gpt4o-mini`, `4o-mini` | `openai/gpt-4o-mini` |
 | `pro`, `gemini` | `google/gemini-2.5-pro` |
@@ -151,8 +151,8 @@ CUSTOM_MODEL_NAME=your-loaded-model
 **Using model aliases (from conf/custom_models.json):**
 ```
 # OpenRouter models:
-"Use opus for deep analysis"         # → anthropic/claude-3-opus
-"Use sonnet to review this code"     # → anthropic/claude-3-sonnet
+"Use opus for deep analysis"         # → anthropic/claude-opus-4
+"Use sonnet to review this code"     # → anthropic/claude-sonnet-4
 "Use pro via zen to analyze this"    # → google/gemini-2.5-pro
 "Use gpt4o via zen to analyze this"  # → openai/gpt-4o
 "Use mistral via zen to optimize"    # → mistral/mistral-large
@@ -165,7 +165,7 @@ CUSTOM_MODEL_NAME=your-loaded-model
 **Using full model names:**
 ```
 # OpenRouter models:
-"Use anthropic/claude-3-opus via zen for deep analysis"
+"Use anthropic/claude-opus-4 via zen for deep analysis"
 "Use openai/gpt-4o via zen to debug this"
 "Use deepseek/deepseek-coder via zen to generate code"
 
@@ -249,7 +249,7 @@ Edit `conf/custom_models.json` to add new models. The configuration supports bot
 
 Popular models available through OpenRouter:
 - **GPT-4** - OpenAI's most capable model
-- **Claude 3** - Anthropic's models (Opus, Sonnet, Haiku)
+- **Claude 4** - Anthropic's models (Opus, Sonnet, Haiku)
 - **Mistral** - Including Mistral Large
 - **Llama 3** - Meta's open models
 - Many more at [openrouter.ai/models](https://openrouter.ai/models)
@@ -258,4 +258,4 @@ Popular models available through OpenRouter:
 
 - **"Model not found"**: Check exact model name at openrouter.ai/models
 - **"Insufficient credits"**: Add credits to your OpenRouter account
-- **"Model not available"**: Check your OpenRouter dashboard for model access permissions
\ No newline at end of file
+- **"Model not available"**: Check your OpenRouter dashboard for model access permissions
diff --git a/providers/registry.py b/providers/registry.py
index 8fa0478..a5efcf0 100644
--- a/providers/registry.py
+++ b/providers/registry.py
@@ -402,8 +402,8 @@ class ModelProviderRegistry:
         if openrouter_provider:
             # Prefer models known for deep reasoning
             preferred_models = [
-                "anthropic/claude-3.5-sonnet",
-                "anthropic/claude-3-opus-20240229",
+                "anthropic/claude-sonnet-4",
+                "anthropic/claude-opus-4",
                 "google/gemini-2.5-pro",
                 "google/gemini-pro-1.5",
                 "meta-llama/llama-3.1-70b-instruct",
diff --git a/simulator_tests/test_openrouter_models.py b/simulator_tests/test_openrouter_models.py
index 5a52efd..bd69806 100644
--- a/simulator_tests/test_openrouter_models.py
+++ b/simulator_tests/test_openrouter_models.py
@@ -117,7 +117,7 @@ class OpenRouterModelsTest(BaseSimulatorTest):
             self.logger.info("  ✅ Direct OpenRouter model call completed")
 
             # Test 5: OpenRouter alias from config
-            self.logger.info("  5: Testing OpenRouter alias from config ('opus' -> anthropic/claude-3-opus)")
+            self.logger.info("  5: Testing OpenRouter alias from config ('opus' -> anthropic/claude-opus-4)")
 
             response5, _ = self.call_mcp_tool(
                 "chat",
diff --git a/tests/test_auto_mode_comprehensive.py b/tests/test_auto_mode_comprehensive.py
index d7e00ae..8539fdf 100644
--- a/tests/test_auto_mode_comprehensive.py
+++ b/tests/test_auto_mode_comprehensive.py
@@ -527,7 +527,7 @@ class TestAutoModeComprehensive:
                 "google/gemini-2.5-pro",
                 "openai/o3",
                 "openai/o4-mini",
-                "anthropic/claude-3-opus",
+                "anthropic/claude-opus-4",
             ]
 
             with patch.object(OpenRouterProvider, "_registry", mock_registry):
diff --git a/tests/test_listmodels_restrictions.py b/tests/test_listmodels_restrictions.py
index 8d26902..5d9f06d 100644
--- a/tests/test_listmodels_restrictions.py
+++ b/tests/test_listmodels_restrictions.py
@@ -53,8 +53,8 @@ class TestListModelsRestrictions(unittest.TestCase):
         # Set up mock to return only allowed models when restrictions are respected
         # Include both aliased models and full model names without aliases
         self.mock_openrouter.list_models.return_value = [
-            "anthropic/claude-3-opus-20240229",  # Has alias "opus"
-            "anthropic/claude-3-sonnet-20240229",  # Has alias "sonnet"
+            "anthropic/claude-opus-4",  # Has alias "opus"
+            "anthropic/claude-sonnet-4",  # Has alias "sonnet"
             "deepseek/deepseek-r1-0528:free",  # No alias, full name
             "qwen/qwen3-235b-a22b-04-28:free",  # No alias, full name
         ]
@@ -67,12 +67,12 @@ class TestListModelsRestrictions(unittest.TestCase):
         def resolve_side_effect(model_name):
             if "opus" in model_name.lower():
                 config = MagicMock()
-                config.model_name = "anthropic/claude-3-opus-20240229"
+                config.model_name = "anthropic/claude-opus-4-20240229"
                 config.context_window = 200000
                 return config
             elif "sonnet" in model_name.lower():
                 config = MagicMock()
-                config.model_name = "anthropic/claude-3-sonnet-20240229"
+                config.model_name = "anthropic/claude-sonnet-4-20240229"
                 config.context_window = 200000
                 return config
             return None  # No config for models without aliases
@@ -93,8 +93,8 @@ class TestListModelsRestrictions(unittest.TestCase):
         mock_get_models.return_value = {
             "gemini-2.5-flash": ProviderType.GOOGLE,
             "gemini-2.5-pro": ProviderType.GOOGLE,
-            "anthropic/claude-3-opus-20240229": ProviderType.OPENROUTER,
-            "anthropic/claude-3-sonnet-20240229": ProviderType.OPENROUTER,
+            "anthropic/claude-opus-4-20240229": ProviderType.OPENROUTER,
+            "anthropic/claude-sonnet-4-20240229": ProviderType.OPENROUTER,
             "deepseek/deepseek-r1-0528:free": ProviderType.OPENROUTER,
             "qwen/qwen3-235b-a22b-04-28:free": ProviderType.OPENROUTER,
         }
@@ -172,7 +172,7 @@ class TestListModelsRestrictions(unittest.TestCase):
         utils.model_restrictions._restriction_service = None
 
         # Set up mock to return many models when no restrictions
-        all_models = [f"provider{i//10}/model-{i}" for i in range(50)]  # Simulate 50 models from different providers
+        all_models = [f"provider{i // 10}/model-{i}" for i in range(50)]  # Simulate 50 models from different providers
         self.mock_openrouter.list_models.return_value = all_models
 
         # Mock registry instance
diff --git a/tests/test_model_restrictions.py b/tests/test_model_restrictions.py
index b4b0e66..bd34a81 100644
--- a/tests/test_model_restrictions.py
+++ b/tests/test_model_restrictions.py
@@ -24,7 +24,7 @@ class TestModelRestrictionService:
             assert service.is_allowed(ProviderType.OPENAI, "o3-mini")
             assert service.is_allowed(ProviderType.GOOGLE, "gemini-2.5-pro")
             assert service.is_allowed(ProviderType.GOOGLE, "gemini-2.5-flash")
-            assert service.is_allowed(ProviderType.OPENROUTER, "anthropic/claude-3-opus")
+            assert service.is_allowed(ProviderType.OPENROUTER, "anthropic/claude-opus-4")
             assert service.is_allowed(ProviderType.OPENROUTER, "openai/o3")
 
             # Should have no restrictions
@@ -44,7 +44,7 @@ class TestModelRestrictionService:
 
             # Google and OpenRouter should have no restrictions
             assert service.is_allowed(ProviderType.GOOGLE, "gemini-2.5-pro")
-            assert service.is_allowed(ProviderType.OPENROUTER, "anthropic/claude-3-opus")
+            assert service.is_allowed(ProviderType.OPENROUTER, "anthropic/claude-opus-4")
 
     def test_load_multiple_models_restriction(self):
         """Test loading multiple allowed models."""
@@ -159,7 +159,7 @@ class TestModelRestrictionService:
             # Should only allow specified OpenRouter models
             assert service.is_allowed(ProviderType.OPENROUTER, "opus")
             assert service.is_allowed(ProviderType.OPENROUTER, "sonnet")
-            assert service.is_allowed(ProviderType.OPENROUTER, "anthropic/claude-3-opus", "opus")  # With original name
+            assert service.is_allowed(ProviderType.OPENROUTER, "anthropic/claude-opus-4", "opus")  # With original name
             assert not service.is_allowed(ProviderType.OPENROUTER, "haiku")
             assert not service.is_allowed(ProviderType.OPENROUTER, "anthropic/claude-3-haiku")
             assert not service.is_allowed(ProviderType.OPENROUTER, "mistral-large")
diff --git a/tests/test_openrouter_provider.py b/tests/test_openrouter_provider.py
index 0dd2b78..da10678 100644
--- a/tests/test_openrouter_provider.py
+++ b/tests/test_openrouter_provider.py
@@ -44,7 +44,7 @@ class TestOpenRouterProvider:
 
         # Should accept any model - OpenRouter handles validation
         assert provider.validate_model_name("gpt-4") is True
-        assert provider.validate_model_name("claude-3-opus") is True
+        assert provider.validate_model_name("claude-4-opus") is True
         assert provider.validate_model_name("any-model-name") is True
         assert provider.validate_model_name("GPT-4") is True
         assert provider.validate_model_name("unknown-model") is True
@@ -71,26 +71,26 @@ class TestOpenRouterProvider:
         provider = OpenRouterProvider(api_key="test-key")
 
         # Test alias resolution
-        assert provider._resolve_model_name("opus") == "anthropic/claude-3-opus"
-        assert provider._resolve_model_name("sonnet") == "anthropic/claude-3-sonnet"
+        assert provider._resolve_model_name("opus") == "anthropic/claude-opus-4"
+        assert provider._resolve_model_name("sonnet") == "anthropic/claude-sonnet-4"
         assert provider._resolve_model_name("o3") == "openai/o3"
         assert provider._resolve_model_name("o3-mini") == "openai/o3-mini"
         assert provider._resolve_model_name("o3mini") == "openai/o3-mini"
         assert provider._resolve_model_name("o4-mini") == "openai/o4-mini"
         assert provider._resolve_model_name("o4-mini-high") == "openai/o4-mini-high"
-        assert provider._resolve_model_name("claude") == "anthropic/claude-3-sonnet"
+        assert provider._resolve_model_name("claude") == "anthropic/claude-sonnet-4"
         assert provider._resolve_model_name("mistral") == "mistralai/mistral-large-2411"
         assert provider._resolve_model_name("deepseek") == "deepseek/deepseek-r1-0528"
         assert provider._resolve_model_name("r1") == "deepseek/deepseek-r1-0528"
 
         # Test case-insensitive
-        assert provider._resolve_model_name("OPUS") == "anthropic/claude-3-opus"
+        assert provider._resolve_model_name("OPUS") == "anthropic/claude-opus-4"
         assert provider._resolve_model_name("O3") == "openai/o3"
         assert provider._resolve_model_name("Mistral") == "mistralai/mistral-large-2411"
-        assert provider._resolve_model_name("CLAUDE") == "anthropic/claude-3-sonnet"
+        assert provider._resolve_model_name("CLAUDE") == "anthropic/claude-sonnet-4"
 
         # Test direct model names (should pass through unchanged)
-        assert provider._resolve_model_name("anthropic/claude-3-opus") == "anthropic/claude-3-opus"
+        assert provider._resolve_model_name("anthropic/claude-opus-4") == "anthropic/claude-opus-4"
         assert provider._resolve_model_name("openai/o3") == "openai/o3"
 
         # Test unknown models pass through
@@ -155,8 +155,8 @@ class TestOpenRouterAutoMode:
             "google/gemini-2.5-pro",
             "openai/o3",
             "openai/o3-mini",
-            "anthropic/claude-3-opus",
-            "anthropic/claude-3-sonnet",
+            "anthropic/claude-opus-4",
+            "anthropic/claude-sonnet-4",
         ]
 
         ModelProviderRegistry.register_provider(ProviderType.OPENROUTER, OpenRouterProvider)
@@ -181,7 +181,7 @@ class TestOpenRouterAutoMode:
         os.environ.pop("OPENAI_API_KEY", None)
         os.environ["OPENROUTER_API_KEY"] = "test-openrouter-key"
         os.environ.pop("OPENROUTER_ALLOWED_MODELS", None)
-        os.environ["OPENROUTER_ALLOWED_MODELS"] = "anthropic/claude-3-opus,google/gemini-2.5-flash"
+        os.environ["OPENROUTER_ALLOWED_MODELS"] = "anthropic/claude-opus-4,google/gemini-2.5-flash"
         os.environ["DEFAULT_MODEL"] = "auto"
 
         # Force reload to pick up new environment variable
@@ -193,8 +193,8 @@ class TestOpenRouterAutoMode:
         mock_models = [
             "google/gemini-2.5-flash",
             "google/gemini-2.5-pro",
-            "anthropic/claude-3-opus",
-            "anthropic/claude-3-sonnet",
+            "anthropic/claude-opus-4",
+            "anthropic/claude-sonnet-4",
         ]
         mock_registry.list_models.return_value = mock_models
 
@@ -212,7 +212,7 @@ class TestOpenRouterAutoMode:
 
         assert len(available_models) > 0, "Should have some allowed models"
 
-        expected_allowed = {"google/gemini-2.5-flash", "anthropic/claude-3-opus"}
+        expected_allowed = {"google/gemini-2.5-flash", "anthropic/claude-opus-4"}
 
         assert (
             set(available_models.keys()) == expected_allowed
@@ -263,7 +263,7 @@ class TestOpenRouterRegistry:
         # Should have loaded models
         models = registry.list_models()
         assert len(models) > 0
-        assert "anthropic/claude-3-opus" in models
+        assert "anthropic/claude-opus-4" in models
         assert "openai/o3" in models
 
         # Should have loaded aliases
@@ -282,13 +282,13 @@ class TestOpenRouterRegistry:
         # Test known model
         caps = registry.get_capabilities("opus")
         assert caps is not None
-        assert caps.model_name == "anthropic/claude-3-opus"
+        assert caps.model_name == "anthropic/claude-opus-4"
         assert caps.context_window == 200000  # Claude's context window
 
         # Test using full model name
-        caps = registry.get_capabilities("anthropic/claude-3-opus")
+        caps = registry.get_capabilities("anthropic/claude-opus-4")
         assert caps is not None
-        assert caps.model_name == "anthropic/claude-3-opus"
+        assert caps.model_name == "anthropic/claude-opus-4"
 
         # Test unknown model
         caps = registry.get_capabilities("non-existent-model")
@@ -301,11 +301,11 @@ class TestOpenRouterRegistry:
         registry = OpenRouterModelRegistry()
 
         # All these should resolve to Claude Sonnet
-        sonnet_aliases = ["sonnet", "claude", "claude-sonnet", "claude3-sonnet"]
+        sonnet_aliases = ["sonnet", "claude", "claude-sonnet", "claude4-sonnet"]
         for alias in sonnet_aliases:
             config = registry.resolve(alias)
             assert config is not None
-            assert config.model_name == "anthropic/claude-3-sonnet"
+            assert config.model_name == "anthropic/claude-sonnet-4"
 
 
 class TestOpenRouterFunctionality:
diff --git a/tests/test_openrouter_registry.py b/tests/test_openrouter_registry.py
index 1a5a2f1..4b8bbbf 100644
--- a/tests/test_openrouter_registry.py
+++ b/tests/test_openrouter_registry.py
@@ -74,9 +74,9 @@ class TestOpenRouterModelRegistry:
 
         # Test various aliases
         test_cases = [
-            ("opus", "anthropic/claude-3-opus"),
-            ("OPUS", "anthropic/claude-3-opus"),  # Case insensitive
-            ("claude", "anthropic/claude-3-sonnet"),
+            ("opus", "anthropic/claude-opus-4"),
+            ("OPUS", "anthropic/claude-opus-4"),  # Case insensitive
+            ("claude", "anthropic/claude-sonnet-4"),
             ("o3", "openai/o3"),
             ("deepseek", "deepseek/deepseek-r1-0528"),
             ("mistral", "mistralai/mistral-large-2411"),
@@ -92,9 +92,9 @@ class TestOpenRouterModelRegistry:
         registry = OpenRouterModelRegistry()
 
         # Should be able to look up by full model name
-        config = registry.resolve("anthropic/claude-3-opus")
+        config = registry.resolve("anthropic/claude-opus-4")
         assert config is not None
-        assert config.model_name == "anthropic/claude-3-opus"
+        assert config.model_name == "anthropic/claude-opus-4"
 
         config = registry.resolve("openai/o3")
         assert config is not None
@@ -118,7 +118,7 @@ class TestOpenRouterModelRegistry:
 
         caps = config.to_capabilities()
         assert caps.provider == ProviderType.OPENROUTER
-        assert caps.model_name == "anthropic/claude-3-opus"
+        assert caps.model_name == "anthropic/claude-opus-4"
         assert caps.friendly_name == "OpenRouter"
         assert caps.context_window == 200000
         assert not caps.supports_extended_thinking
diff --git a/tests/test_per_tool_model_defaults.py b/tests/test_per_tool_model_defaults.py
index 92c904c..f2b9b5e 100644
--- a/tests/test_per_tool_model_defaults.py
+++ b/tests/test_per_tool_model_defaults.py
@@ -288,11 +288,11 @@ class TestProviderHelperMethods:
         with patch.object(ModelProviderRegistry, "get_provider") as mock_get_provider:
             # Mock openrouter provider
             mock_openrouter = MagicMock()
-            mock_openrouter.validate_model_name.side_effect = lambda m: m == "anthropic/claude-3.5-sonnet"
+            mock_openrouter.validate_model_name.side_effect = lambda m: m == "anthropic/claude-sonnet-4"
             mock_get_provider.side_effect = lambda ptype: mock_openrouter if ptype == ProviderType.OPENROUTER else None
 
             model = ModelProviderRegistry._find_extended_thinking_model()
-            assert model == "anthropic/claude-3.5-sonnet"
+            assert model == "anthropic/claude-sonnet-4"
 
     def test_find_extended_thinking_model_none_found(self):
         """Test when no thinking model is found."""
diff --git a/tests/test_provider_routing_bugs.py b/tests/test_provider_routing_bugs.py
index 2ceda5a..9ed125b 100644
--- a/tests/test_provider_routing_bugs.py
+++ b/tests/test_provider_routing_bugs.py
@@ -318,7 +318,7 @@ class TestOpenRouterAliasRestrictions:
             os.environ.pop("OPENAI_API_KEY", None)
             os.environ.pop("XAI_API_KEY", None)
             os.environ["OPENROUTER_API_KEY"] = "test-key"
-            os.environ["OPENROUTER_ALLOWED_MODELS"] = "o3-mini,anthropic/claude-3-opus,flash"
+            os.environ["OPENROUTER_ALLOWED_MODELS"] = "o3-mini,anthropic/claude-opus-4,flash"
 
             # Register OpenRouter provider
             from providers.openrouter import OpenRouterProvider
@@ -330,7 +330,7 @@ class TestOpenRouterAliasRestrictions:
 
             expected_models = {
                 "openai/o3-mini",  # from alias
-                "anthropic/claude-3-opus",  # full name
+                "anthropic/claude-opus-4",  # full name
                 "google/gemini-2.5-flash",  # from alias
             }
 
diff --git a/tools/shared/base_tool.py b/tools/shared/base_tool.py
index 7bff37f..a98baf8 100644
--- a/tools/shared/base_tool.py
+++ b/tools/shared/base_tool.py
@@ -448,7 +448,7 @@ class BaseTool(ABC):
                 except Exception:
                     description += (
                         " OpenRouter: Any model available on openrouter.ai "
-                        "(e.g., 'gpt-4', 'claude-3-opus', 'mistral-large')."
+                        "(e.g., 'gpt-4', 'claude-4-opus', 'mistral-large')."
                     )
             description += f" Defaults to '{DEFAULT_MODEL}' if not specified."