feat: enhance AnthropicCompletion class with additional client parameters and tool handling

- Added support for client_params in the AnthropicCompletion class to allow for additional client configuration.
- Refactored client initialization to use a dedicated method for retrieving client parameters.
- Implemented a new method to handle tool use conversation flow, ensuring proper execution and response handling.
- Introduced comprehensive test cases to validate the functionality of the AnthropicCompletion class, including tool use scenarios and parameter handling.

lib/crewai/src/crewai/llms/providers/anthropic/completion.py

@@ -40,6 +40,7 @@ class AnthropicCompletion(BaseLLM):
         top_p: float | None = None,
         stop_sequences: list[str] | None = None,
         stream: bool = False,
+        client_params: dict[str, Any] | None = None,
         **kwargs,
     ):
         """Initialize Anthropic chat completion client.
@@ -55,19 +56,20 @@ class AnthropicCompletion(BaseLLM):
             top_p: Nucleus sampling parameter
             stop_sequences: Stop sequences (Anthropic uses stop_sequences, not stop)
             stream: Enable streaming responses
+            client_params: Additional parameters for the Anthropic client
             **kwargs: Additional parameters
         """
         super().__init__(
             model=model, temperature=temperature, stop=stop_sequences or [], **kwargs
         )
 
-        # Initialize Anthropic client
-        self.client = Anthropic(
-            api_key=api_key or os.getenv("ANTHROPIC_API_KEY"),
-            base_url=base_url,
-            timeout=timeout,
-            max_retries=max_retries,
-        )
+        # Client params
+        self.client_params = client_params
+        self.base_url = base_url
+        self.timeout = timeout
+        self.max_retries = max_retries
+
+        self.client = Anthropic(**self._get_client_params())
 
         # Store completion parameters
         self.max_tokens = max_tokens
@@ -79,6 +81,26 @@ class AnthropicCompletion(BaseLLM):
         self.is_claude_3 = "claude-3" in model.lower()
         self.supports_tools = self.is_claude_3  # Claude 3+ supports tool use
 
+    def _get_client_params(self) -> dict[str, Any]:
+        """Get client parameters."""
+
+        if self.api_key is None:
+            self.api_key = os.getenv("ANTHROPIC_API_KEY")
+            if self.api_key is None:
+                raise ValueError("ANTHROPIC_API_KEY is required")
+
+        client_params = {
+            "api_key": self.api_key,
+            "base_url": self.base_url,
+            "timeout": self.timeout,
+            "max_retries": self.max_retries,
+        }
+
+        if self.client_params:
+            client_params.update(self.client_params)
+
+        return client_params
+
     def call(
         self,
         messages: str | list[dict[str, str]],
@@ -102,6 +124,7 @@ class AnthropicCompletion(BaseLLM):
             Chat completion response or tool call result
         """
         try:
+            print("we are calling", messages)
             # Emit call started event
             self._emit_call_started_event(
                 messages=messages,
@@ -121,6 +144,7 @@ class AnthropicCompletion(BaseLLM):
             completion_params = self._prepare_completion_params(
                 formatted_messages, system_message, tools
             )
+            print("completion_params", completion_params)
 
             # Handle streaming vs non-streaming
             if self.stream:
@@ -183,12 +207,25 @@ class AnthropicCompletion(BaseLLM):
 
     def _convert_tools_for_interference(self, tools: list[dict]) -> list[dict]:
         """Convert CrewAI tool format to Anthropic tool use format."""
-        from crewai.llms.providers.utils.common import safe_tool_conversion
-
         anthropic_tools = []
 
         for tool in tools:
-            name, description, parameters = safe_tool_conversion(tool, "Anthropic")
+            if "input_schema" in tool and "name" in tool and "description" in tool:
+                anthropic_tools.append(tool)
+                continue
+
+            try:
+                from crewai.llms.providers.utils.common import safe_tool_conversion
+
+                name, description, parameters = safe_tool_conversion(tool, "Anthropic")
+            except (ImportError, Exception):
+                name = tool.get("name", "unknown_tool")
+                description = tool.get("description", "A tool function")
+                parameters = (
+                    tool.get("input_schema")
+                    or tool.get("parameters")
+                    or tool.get("schema")
+                )
 
             anthropic_tool = {
                 "name": name,
@@ -196,7 +233,13 @@ class AnthropicCompletion(BaseLLM):
             }
 
             if parameters and isinstance(parameters, dict):
-                anthropic_tool["input_schema"] = parameters  # type: ignore
+                anthropic_tool["input_schema"] = parameters
+            else:
+                anthropic_tool["input_schema"] = {
+                    "type": "object",
+                    "properties": {},
+                    "required": [],
+                }
 
             anthropic_tools.append(anthropic_tool)
 
@@ -229,13 +272,11 @@ class AnthropicCompletion(BaseLLM):
             content = message.get("content", "")
 
             if role == "system":
-                # Extract system message - Anthropic handles it separately
                 if system_message:
                     system_message += f"\n\n{content}"
                 else:
                     system_message = content
             else:
-                # Add user/assistant messages - ensure both role and content are str, not None
                 role_str = role if role is not None else "user"
                 content_str = content if content is not None else ""
                 formatted_messages.append({"role": role_str, "content": content_str})
@@ -259,6 +300,7 @@ class AnthropicCompletion(BaseLLM):
     ) -> str | Any:
         """Handle non-streaming message completion."""
         try:
+            print("params", params)
             response: Message = self.client.messages.create(**params)
 
         except Exception as e:
@@ -270,22 +312,22 @@ class AnthropicCompletion(BaseLLM):
         usage = self._extract_anthropic_token_usage(response)
         self._track_token_usage_internal(usage)
 
+        # Check if Claude wants to use tools
         if response.content and available_functions:
-            for content_block in response.content:
-                if isinstance(content_block, ToolUseBlock):
-                    function_name = content_block.name
-                    function_args = content_block.input
+            tool_uses = [
+                block for block in response.content if isinstance(block, ToolUseBlock)
+            ]
 
-                    result = self._handle_tool_execution(
-                        function_name=function_name,
-                        function_args=function_args,  # type: ignore
-                        available_functions=available_functions,
-                        from_task=from_task,
-                        from_agent=from_agent,
-                    )
-
-                    if result is not None:
-                        return result
+            if tool_uses:
+                # Handle tool use conversation flow
+                return self._handle_tool_use_conversation(
+                    response,
+                    tool_uses,
+                    params,
+                    available_functions,
+                    from_task,
+                    from_agent,
+                )
 
         # Extract text content
         content = ""
@@ -350,26 +392,54 @@ class AnthropicCompletion(BaseLLM):
 
         # Handle completed tool uses
         if tool_uses and available_functions:
-            for tool_data in tool_uses.values():
-                function_name = tool_data["name"]
-
+            # Convert streamed tool uses to ToolUseBlock-like objects for consistency
+            tool_use_blocks = []
+            for tool_id, tool_data in tool_uses.items():
                 try:
                     function_args = json.loads(tool_data["input"])
                 except json.JSONDecodeError as e:
                     logging.error(f"Failed to parse streamed tool arguments: {e}")
                     continue
 
-                # Execute tool
-                result = self._handle_tool_execution(
-                    function_name=function_name,
-                    function_args=function_args,
-                    available_functions=available_functions,
-                    from_task=from_task,
-                    from_agent=from_agent,
+                # Create a mock ToolUseBlock-like object
+                class MockToolUse:
+                    def __init__(self, tool_id: str, name: str, input_args: dict):
+                        self.id = tool_id
+                        self.name = name
+                        self.input = input_args
+
+                tool_use_blocks.append(
+                    MockToolUse(tool_id, tool_data["name"], function_args)
                 )
 
-                if result is not None:
-                    return result
+            if tool_use_blocks:
+                # Create a mock response object for the tool conversation flow
+                class MockResponse:
+                    def __init__(self, content_blocks):
+                        self.content = content_blocks
+
+                # Combine text content and tool uses in the response
+                response_content = []
+                if full_response.strip():  # Add text content if any
+
+                    class MockTextBlock:
+                        def __init__(self, text: str):
+                            self.text = text
+
+                    response_content.append(MockTextBlock(full_response))
+
+                response_content.extend(tool_use_blocks)
+                mock_response = MockResponse(response_content)
+
+                # Handle tool use conversation flow
+                return self._handle_tool_use_conversation(
+                    mock_response,
+                    tool_use_blocks,
+                    params,
+                    available_functions,
+                    from_task,
+                    from_agent,
+                )
 
         # Apply stop words to full response
         full_response = self._apply_stop_words(full_response)
@@ -385,6 +455,115 @@ class AnthropicCompletion(BaseLLM):
 
         return full_response
 
+    def _handle_tool_use_conversation(
+        self,
+        initial_response: Message
+        | Any,  # Can be Message or mock response from streaming
+        tool_uses: list[ToolUseBlock]
+        | list[Any],  # Can be ToolUseBlock or mock objects
+        params: dict[str, Any],
+        available_functions: dict[str, Any],
+        from_task: Any | None = None,
+        from_agent: Any | None = None,
+    ) -> str:
+        """Handle the complete tool use conversation flow.
+
+        This implements the proper Anthropic tool use pattern:
+        1. Claude requests tool use
+        2. We execute the tools
+        3. We send tool results back to Claude
+        4. Claude processes results and generates final response
+        """
+        # Execute all requested tools and collect results
+        tool_results = []
+
+        for tool_use in tool_uses:
+            function_name = tool_use.name
+            function_args = tool_use.input
+
+            # Execute the tool
+            result = self._handle_tool_execution(
+                function_name=function_name,
+                function_args=function_args,  # type: ignore
+                available_functions=available_functions,
+                from_task=from_task,
+                from_agent=from_agent,
+            )
+
+            # Create tool result in Anthropic format
+            tool_result = {
+                "type": "tool_result",
+                "tool_use_id": tool_use.id,
+                "content": str(result)
+                if result is not None
+                else "Tool execution completed",
+            }
+            tool_results.append(tool_result)
+
+        # Prepare follow-up conversation with tool results
+        follow_up_params = params.copy()
+
+        # Add Claude's tool use response to conversation
+        assistant_message = {"role": "assistant", "content": initial_response.content}
+
+        # Add user message with tool results
+        user_message = {"role": "user", "content": tool_results}
+
+        # Update messages for follow-up call
+        follow_up_params["messages"] = params["messages"] + [
+            assistant_message,
+            user_message,
+        ]
+
+        try:
+            # Send tool results back to Claude for final response
+            final_response: Message = self.client.messages.create(**follow_up_params)
+
+            # Track token usage for follow-up call
+            follow_up_usage = self._extract_anthropic_token_usage(final_response)
+            self._track_token_usage_internal(follow_up_usage)
+
+            # Extract final text content
+            final_content = ""
+            if final_response.content:
+                for content_block in final_response.content:
+                    if hasattr(content_block, "text"):
+                        final_content += content_block.text
+
+            final_content = self._apply_stop_words(final_content)
+
+            # Emit completion event for the final response
+            self._emit_call_completed_event(
+                response=final_content,
+                call_type=LLMCallType.LLM_CALL,
+                from_task=from_task,
+                from_agent=from_agent,
+                messages=follow_up_params["messages"],
+            )
+
+            # Log combined token usage
+            total_usage = {
+                "input_tokens": follow_up_usage.get("input_tokens", 0),
+                "output_tokens": follow_up_usage.get("output_tokens", 0),
+                "total_tokens": follow_up_usage.get("total_tokens", 0),
+            }
+
+            if total_usage.get("total_tokens", 0) > 0:
+                logging.info(f"Anthropic API tool conversation usage: {total_usage}")
+
+            return final_content
+
+        except Exception as e:
+            if is_context_length_exceeded(e):
+                logging.error(f"Context window exceeded in tool follow-up: {e}")
+                raise LLMContextLengthExceededError(str(e)) from e
+
+            logging.error(f"Tool follow-up conversation failed: {e}")
+            # Fallback: return the first tool result if follow-up fails
+            if tool_results:
+                return tool_results[0]["content"]
+            raise e
+
     def supports_function_calling(self) -> bool:
         """Check if the model supports function calling."""
         return self.supports_tools

lib/crewai/tests/llms/anthropic/test_anthropic.py

@@ -0,0 +1,660 @@
+import os
+import sys
+import types
+from unittest.mock import patch, MagicMock
+import pytest
+
+from crewai.llm import LLM
+from crewai.llms.providers.anthropic.completion import AnthropicCompletion
+from crewai.crew import Crew
+from crewai.agent import Agent
+from crewai.task import Task
+from crewai.cli.constants import DEFAULT_LLM_MODEL
+
+
+def test_anthropic_completion_is_used_when_anthropic_provider():
+    """
+    Test that AnthropicCompletion from completion.py is used when LLM uses provider 'anthropic'
+    """
+    llm = LLM(model="anthropic/claude-3-5-sonnet-20241022")
+
+    assert llm.__class__.__name__ == "AnthropicCompletion"
+    assert llm.provider == "anthropic"
+    assert llm.model == "claude-3-5-sonnet-20241022"
+
+
+def test_anthropic_completion_is_used_when_claude_provider():
+    """
+    Test that AnthropicCompletion is used when provider is 'claude'
+    """
+    llm = LLM(model="claude/claude-3-5-sonnet-20241022")
+
+    from crewai.llms.providers.anthropic.completion import AnthropicCompletion
+    assert isinstance(llm, AnthropicCompletion)
+    assert llm.provider == "claude"
+    assert llm.model == "claude-3-5-sonnet-20241022"
+
+
+
+
+def test_anthropic_tool_use_conversation_flow():
+    """
+    Test that the Anthropic completion properly handles tool use conversation flow
+    """
+    from unittest.mock import Mock, patch
+    from crewai.llms.providers.anthropic.completion import AnthropicCompletion
+    from anthropic.types.tool_use_block import ToolUseBlock
+
+    # Create AnthropicCompletion instance
+    completion = AnthropicCompletion(model="claude-3-5-sonnet-20241022")
+
+    # Mock tool function
+    def mock_weather_tool(location: str) -> str:
+        return f"The weather in {location} is sunny and 75°F"
+
+    available_functions = {"get_weather": mock_weather_tool}
+
+    # Mock the Anthropic client responses
+    with patch.object(completion.client.messages, 'create') as mock_create:
+        # Mock initial response with tool use - need to properly mock ToolUseBlock
+        mock_tool_use = Mock(spec=ToolUseBlock)
+        mock_tool_use.id = "tool_123"
+        mock_tool_use.name = "get_weather"
+        mock_tool_use.input = {"location": "San Francisco"}
+
+        mock_initial_response = Mock()
+        mock_initial_response.content = [mock_tool_use]
+        mock_initial_response.usage = Mock()
+        mock_initial_response.usage.input_tokens = 100
+        mock_initial_response.usage.output_tokens = 50
+
+        # Mock final response after tool result - properly mock text content
+        mock_text_block = Mock()
+        # Set the text attribute as a string, not another Mock
+        mock_text_block.configure_mock(text="Based on the weather data, it's a beautiful day in San Francisco with sunny skies and 75°F temperature.")
+
+        mock_final_response = Mock()
+        mock_final_response.content = [mock_text_block]
+        mock_final_response.usage = Mock()
+        mock_final_response.usage.input_tokens = 150
+        mock_final_response.usage.output_tokens = 75
+
+        # Configure mock to return different responses on successive calls
+        mock_create.side_effect = [mock_initial_response, mock_final_response]
+
+        # Test the call
+        messages = [{"role": "user", "content": "What's the weather like in San Francisco?"}]
+        result = completion.call(
+            messages=messages,
+            available_functions=available_functions
+        )
+
+        # Verify the result contains the final response
+        assert "beautiful day in San Francisco" in result
+        assert "sunny skies" in result
+        assert "75°F" in result
+
+        # Verify that two API calls were made (initial + follow-up)
+        assert mock_create.call_count == 2
+
+        # Verify the second call includes tool results
+        second_call_args = mock_create.call_args_list[1][1]  # kwargs of second call
+        messages_in_second_call = second_call_args["messages"]
+
+        # Should have original user message + assistant tool use + user tool result
+        assert len(messages_in_second_call) == 3
+        assert messages_in_second_call[0]["role"] == "user"
+        assert messages_in_second_call[1]["role"] == "assistant"
+        assert messages_in_second_call[2]["role"] == "user"
+
+        # Verify tool result format
+        tool_result = messages_in_second_call[2]["content"][0]
+        assert tool_result["type"] == "tool_result"
+        assert tool_result["tool_use_id"] == "tool_123"
+        assert "sunny and 75°F" in tool_result["content"]
+
+
+def test_anthropic_completion_module_is_imported():
+    """
+    Test that the completion module is properly imported when using Anthropic provider
+    """
+    module_name = "crewai.llms.providers.anthropic.completion"
+
+    # Remove module from cache if it exists
+    if module_name in sys.modules:
+        del sys.modules[module_name]
+
+    # Create LLM instance - this should trigger the import
+    LLM(model="anthropic/claude-3-5-sonnet-20241022")
+
+    # Verify the module was imported
+    assert module_name in sys.modules
+    completion_mod = sys.modules[module_name]
+    assert isinstance(completion_mod, types.ModuleType)
+
+    # Verify the class exists in the module
+    assert hasattr(completion_mod, 'AnthropicCompletion')
+
+
+def test_fallback_to_litellm_when_native_anthropic_fails():
+    """
+    Test that LLM falls back to LiteLLM when native Anthropic completion fails
+    """
+    # Mock the _get_native_provider to return a failing class
+    with patch('crewai.llm.LLM._get_native_provider') as mock_get_provider:
+
+        class FailingCompletion:
+            def __init__(self, *args, **kwargs):
+                raise Exception("Native Anthropic SDK failed")
+
+        mock_get_provider.return_value = FailingCompletion
+
+        # This should fall back to LiteLLM
+        llm = LLM(model="anthropic/claude-3-5-sonnet-20241022")
+
+        # Check that it's using LiteLLM
+        assert hasattr(llm, 'is_litellm')
+        assert llm.is_litellm == True
+
+
+def test_anthropic_completion_initialization_parameters():
+    """
+    Test that AnthropicCompletion is initialized with correct parameters
+    """
+    llm = LLM(
+        model="anthropic/claude-3-5-sonnet-20241022",
+        temperature=0.7,
+        max_tokens=2000,
+        top_p=0.9,
+        api_key="test-key"
+    )
+
+    from crewai.llms.providers.anthropic.completion import AnthropicCompletion
+    assert isinstance(llm, AnthropicCompletion)
+    assert llm.model == "claude-3-5-sonnet-20241022"
+    assert llm.temperature == 0.7
+    assert llm.max_tokens == 2000
+    assert llm.top_p == 0.9
+
+
+def test_anthropic_specific_parameters():
+    """
+    Test Anthropic-specific parameters like stop_sequences and streaming
+    """
+    llm = LLM(
+        model="anthropic/claude-3-5-sonnet-20241022",
+        stop_sequences=["Human:", "Assistant:"],
+        stream=True,
+        max_retries=5,
+        timeout=60
+    )
+
+    from crewai.llms.providers.anthropic.completion import AnthropicCompletion
+    assert isinstance(llm, AnthropicCompletion)
+    assert llm.stop_sequences == ["Human:", "Assistant:"]
+    assert llm.stream == True
+    assert llm.client.max_retries == 5
+    assert llm.client.timeout == 60
+
+
+def test_anthropic_completion_call():
+    """
+    Test that AnthropicCompletion call method works
+    """
+    llm = LLM(model="anthropic/claude-3-5-sonnet-20241022")
+
+    # Mock the call method on the instance
+    with patch.object(llm, 'call', return_value="Hello! I'm Claude, ready to help.") as mock_call:
+        result = llm.call("Hello, how are you?")
+
+        assert result == "Hello! I'm Claude, ready to help."
+        mock_call.assert_called_once_with("Hello, how are you?")
+
+
+def test_anthropic_completion_called_during_crew_execution():
+    """
+    Test that AnthropicCompletion.call is actually invoked when running a crew
+    """
+    # Create the LLM instance first
+    anthropic_llm = LLM(model="anthropic/claude-3-5-sonnet-20241022")
+
+    # Mock the call method on the specific instance
+    with patch.object(anthropic_llm, 'call', return_value="Tokyo has 14 million people.") as mock_call:
+
+        # Create agent with explicit LLM configuration
+        agent = Agent(
+            role="Research Assistant",
+            goal="Find population info",
+            backstory="You research populations.",
+            llm=anthropic_llm,
+        )
+
+        task = Task(
+            description="Find Tokyo population",
+            expected_output="Population number",
+            agent=agent,
+        )
+
+        crew = Crew(agents=[agent], tasks=[task])
+        result = crew.kickoff()
+
+        # Verify mock was called
+        assert mock_call.called
+        assert "14 million" in str(result)
+
+
+def test_anthropic_completion_call_arguments():
+    """
+    Test that AnthropicCompletion.call is invoked with correct arguments
+    """
+    # Create LLM instance first
+    anthropic_llm = LLM(model="anthropic/claude-3-5-sonnet-20241022")
+
+    # Mock the instance method
+    with patch.object(anthropic_llm, 'call') as mock_call:
+        mock_call.return_value = "Task completed successfully."
+
+        agent = Agent(
+            role="Test Agent",
+            goal="Complete a simple task",
+            backstory="You are a test agent.",
+            llm=anthropic_llm  # Use same instance
+        )
+
+        task = Task(
+            description="Say hello world",
+            expected_output="Hello world",
+            agent=agent,
+        )
+
+        crew = Crew(agents=[agent], tasks=[task])
+        crew.kickoff()
+
+        # Verify call was made
+        assert mock_call.called
+
+        # Check the arguments passed to the call method
+        call_args = mock_call.call_args
+        assert call_args is not None
+
+        # The first argument should be the messages
+        messages = call_args[0][0]  # First positional argument
+        assert isinstance(messages, (str, list))
+
+        # Verify that the task description appears in the messages
+        if isinstance(messages, str):
+            assert "hello world" in messages.lower()
+        elif isinstance(messages, list):
+            message_content = str(messages).lower()
+            assert "hello world" in message_content
+
+
+def test_multiple_anthropic_calls_in_crew():
+    """
+    Test that AnthropicCompletion.call is invoked multiple times for multiple tasks
+    """
+    # Create LLM instance first
+    anthropic_llm = LLM(model="anthropic/claude-3-5-sonnet-20241022")
+
+    # Mock the instance method
+    with patch.object(anthropic_llm, 'call') as mock_call:
+        mock_call.return_value = "Task completed."
+
+        agent = Agent(
+            role="Multi-task Agent",
+            goal="Complete multiple tasks",
+            backstory="You can handle multiple tasks.",
+            llm=anthropic_llm  # Use same instance
+        )
+
+        task1 = Task(
+            description="First task",
+            expected_output="First result",
+            agent=agent,
+        )
+
+        task2 = Task(
+            description="Second task",
+            expected_output="Second result",
+            agent=agent,
+        )
+
+        crew = Crew(
+            agents=[agent],
+            tasks=[task1, task2]
+        )
+        crew.kickoff()
+
+        # Verify multiple calls were made
+        assert mock_call.call_count >= 2  # At least one call per task
+
+        # Verify each call had proper arguments
+        for call in mock_call.call_args_list:
+            assert len(call[0]) > 0  # Has positional arguments
+            messages = call[0][0]
+            assert messages is not None
+
+
+def test_anthropic_completion_with_tools():
+    """
+    Test that AnthropicCompletion.call is invoked with tools when agent has tools
+    """
+    from crewai.tools import tool
+
+    @tool
+    def sample_tool(query: str) -> str:
+        """A sample tool for testing"""
+        return f"Tool result for: {query}"
+
+    # Create LLM instance first
+    anthropic_llm = LLM(model="anthropic/claude-3-5-sonnet-20241022")
+
+    # Mock the instance method
+    with patch.object(anthropic_llm, 'call') as mock_call:
+        mock_call.return_value = "Task completed with tools."
+
+        agent = Agent(
+            role="Tool User",
+            goal="Use tools to complete tasks",
+            backstory="You can use tools.",
+            llm=anthropic_llm,  # Use same instance
+            tools=[sample_tool]
+        )
+
+        task = Task(
+            description="Use the sample tool",
+            expected_output="Tool usage result",
+            agent=agent,
+        )
+
+        crew = Crew(agents=[agent], tasks=[task])
+        crew.kickoff()
+
+        assert mock_call.called
+
+        call_args = mock_call.call_args
+        call_kwargs = call_args[1] if len(call_args) > 1 else {}
+
+        if 'tools' in call_kwargs:
+            assert call_kwargs['tools'] is not None
+            assert len(call_kwargs['tools']) > 0
+
+
+def test_anthropic_raises_error_when_model_not_supported():
+    """Test that AnthropicCompletion raises ValueError when model not supported"""
+
+    # Mock the Anthropic client to raise an error
+    with patch('crewai.llms.providers.anthropic.completion.Anthropic') as mock_anthropic_class:
+        mock_client = MagicMock()
+        mock_anthropic_class.return_value = mock_client
+
+        # Mock the error that Anthropic would raise for unsupported models
+        from anthropic import NotFoundError
+        mock_client.messages.create.side_effect = NotFoundError(
+            message="The model `model-doesnt-exist` does not exist",
+            response=MagicMock(),
+            body={}
+        )
+
+        llm = LLM(model="anthropic/model-doesnt-exist")
+
+        with pytest.raises(Exception):  # Should raise some error for unsupported model
+            llm.call("Hello")
+
+
+def test_anthropic_client_params_setup():
+    """
+    Test that client_params are properly merged with default client parameters
+    """
+    # Use only valid Anthropic client parameters
+    custom_client_params = {
+        "default_headers": {"X-Custom-Header": "test-value"},
+    }
+
+    with patch.dict(os.environ, {"ANTHROPIC_API_KEY": "test-key"}):
+        llm = LLM(
+            model="anthropic/claude-3-5-sonnet-20241022",
+            api_key="test-key",
+            base_url="https://custom-api.com",
+            timeout=45,
+            max_retries=5,
+            client_params=custom_client_params
+        )
+
+        from crewai.llms.providers.anthropic.completion import AnthropicCompletion
+        assert isinstance(llm, AnthropicCompletion)
+
+        assert llm.client_params == custom_client_params
+
+        merged_params = llm._get_client_params()
+
+        assert merged_params["api_key"] == "test-key"
+        assert merged_params["base_url"] == "https://custom-api.com"
+        assert merged_params["timeout"] == 45
+        assert merged_params["max_retries"] == 5
+
+        assert merged_params["default_headers"] == {"X-Custom-Header": "test-value"}
+
+
+def test_anthropic_client_params_override_defaults():
+    """
+    Test that client_params can override default client parameters
+    """
+    override_client_params = {
+        "timeout": 120,  # Override the timeout parameter
+        "max_retries": 10,  # Override the max_retries parameter
+        "default_headers": {"X-Override": "true"}  # Valid custom parameter
+    }
+
+    with patch.dict(os.environ, {"ANTHROPIC_API_KEY": "test-key"}):
+        llm = LLM(
+            model="anthropic/claude-3-5-sonnet-20241022",
+            api_key="test-key",
+            timeout=30,
+            max_retries=3,
+            client_params=override_client_params
+        )
+
+        # Verify this is actually AnthropicCompletion, not LiteLLM fallback
+        from crewai.llms.providers.anthropic.completion import AnthropicCompletion
+        assert isinstance(llm, AnthropicCompletion)
+
+        merged_params = llm._get_client_params()
+
+        # client_params should override the individual parameters
+        assert merged_params["timeout"] == 120
+        assert merged_params["max_retries"] == 10
+        assert merged_params["default_headers"] == {"X-Override": "true"}
+
+
+def test_anthropic_client_params_none():
+    """
+    Test that client_params=None works correctly (no additional parameters)
+    """
+    with patch.dict(os.environ, {"ANTHROPIC_API_KEY": "test-key"}):
+        llm = LLM(
+            model="anthropic/claude-3-5-sonnet-20241022",
+            api_key="test-key",
+            base_url="https://api.anthropic.com",
+            timeout=60,
+            max_retries=2,
+            client_params=None
+        )
+
+        from crewai.llms.providers.anthropic.completion import AnthropicCompletion
+        assert isinstance(llm, AnthropicCompletion)
+
+        assert llm.client_params is None
+
+        merged_params = llm._get_client_params()
+
+        expected_keys = {"api_key", "base_url", "timeout", "max_retries"}
+        assert set(merged_params.keys()) == expected_keys
+
+        # Fixed assertions - all should be inside the with block and use correct values
+        assert merged_params["api_key"] == "test-key"  # Not "test-anthropic-key"
+        assert merged_params["base_url"] == "https://api.anthropic.com"
+        assert merged_params["timeout"] == 60
+        assert merged_params["max_retries"] == 2
+
+
+def test_anthropic_client_params_empty_dict():
+    """
+    Test that client_params={} works correctly (empty additional parameters)
+    """
+    with patch.dict(os.environ, {"ANTHROPIC_API_KEY": "test-key"}):
+        llm = LLM(
+            model="anthropic/claude-3-5-sonnet-20241022",
+            api_key="test-key",
+            client_params={}
+        )
+
+        from crewai.llms.providers.anthropic.completion import AnthropicCompletion
+        assert isinstance(llm, AnthropicCompletion)
+
+        assert llm.client_params == {}
+
+        merged_params = llm._get_client_params()
+
+        assert "api_key" in merged_params
+        assert merged_params["api_key"] == "test-key"
+
+
+def test_anthropic_model_detection():
+    """
+    Test that various Anthropic model formats are properly detected
+    """
+    # Test Anthropic model naming patterns that actually work with provider detection
+    anthropic_test_cases = [
+        "anthropic/claude-3-5-sonnet-20241022",
+        "claude/claude-3-5-sonnet-20241022"
+    ]
+
+    for model_name in anthropic_test_cases:
+        llm = LLM(model=model_name)
+        from crewai.llms.providers.anthropic.completion import AnthropicCompletion
+        assert isinstance(llm, AnthropicCompletion), f"Failed for model: {model_name}"
+
+
+def test_anthropic_supports_stop_words():
+    """
+    Test that Anthropic models support stop sequences
+    """
+    llm = LLM(model="anthropic/claude-3-5-sonnet-20241022")
+    assert llm.supports_stop_words() == True
+
+
+def test_anthropic_context_window_size():
+    """
+    Test that Anthropic models return correct context window sizes
+    """
+    llm = LLM(model="anthropic/claude-3-5-sonnet-20241022")
+    context_size = llm.get_context_window_size()
+
+    # Should return a reasonable context window size (Claude 3.5 has 200k tokens)
+    assert context_size > 100000  # Should be substantial
+    assert context_size <= 200000  # But not exceed the actual limit
+
+
+def test_anthropic_message_formatting():
+    """
+    Test that messages are properly formatted for Anthropic API
+    """
+    llm = LLM(model="anthropic/claude-3-5-sonnet-20241022")
+
+    # Test message formatting
+    test_messages = [
+        {"role": "system", "content": "You are a helpful assistant."},
+        {"role": "user", "content": "Hello"},
+        {"role": "assistant", "content": "Hi there!"},
+        {"role": "user", "content": "How are you?"}
+    ]
+
+    formatted_messages, system_message = llm._format_messages_for_anthropic(test_messages)
+
+    # System message should be extracted
+    assert system_message == "You are a helpful assistant."
+
+    # Remaining messages should start with user
+    assert formatted_messages[0]["role"] == "user"
+    assert len(formatted_messages) >= 3  # Should have user, assistant, user messages
+
+
+def test_anthropic_streaming_parameter():
+    """
+    Test that streaming parameter is properly handled
+    """
+    # Test non-streaming
+    llm_no_stream = LLM(model="anthropic/claude-3-5-sonnet-20241022", stream=False)
+    assert llm_no_stream.stream == False
+
+    # Test streaming
+    llm_stream = LLM(model="anthropic/claude-3-5-sonnet-20241022", stream=True)
+    assert llm_stream.stream == True
+
+
+def test_anthropic_tool_conversion():
+    """
+    Test that tools are properly converted to Anthropic format
+    """
+    llm = LLM(model="anthropic/claude-3-5-sonnet-20241022")
+
+    # Mock tool in CrewAI format
+    crewai_tools = [{
+        "type": "function",
+        "function": {
+            "name": "test_tool",
+            "description": "A test tool",
+            "parameters": {
+                "type": "object",
+                "properties": {
+                    "query": {"type": "string", "description": "Search query"}
+                },
+                "required": ["query"]
+            }
+        }
+    }]
+
+    # Test tool conversion
+    anthropic_tools = llm._convert_tools_for_interference(crewai_tools)
+
+    assert len(anthropic_tools) == 1
+    assert anthropic_tools[0]["name"] == "test_tool"
+    assert anthropic_tools[0]["description"] == "A test tool"
+    assert "input_schema" in anthropic_tools[0]
+
+
+def test_anthropic_environment_variable_api_key():
+    """
+    Test that Anthropic API key is properly loaded from environment
+    """
+    with patch.dict(os.environ, {"ANTHROPIC_API_KEY": "test-anthropic-key"}):
+        llm = LLM(model="anthropic/claude-3-5-sonnet-20241022")
+
+        assert llm.client is not None
+        assert hasattr(llm.client, 'messages')
+
+
+def test_anthropic_token_usage_tracking():
+    """
+    Test that token usage is properly tracked for Anthropic responses
+    """
+    llm = LLM(model="anthropic/claude-3-5-sonnet-20241022")
+
+    # Mock the Anthropic response with usage information
+    with patch.object(llm.client.messages, 'create') as mock_create:
+        mock_response = MagicMock()
+        mock_response.content = [MagicMock(text="test response")]
+        mock_response.usage = MagicMock(input_tokens=50, output_tokens=25)
+        mock_create.return_value = mock_response
+
+        result = llm.call("Hello")
+
+        # Verify the response
+        assert result == "test response"
+
+        # Verify token usage was extracted
+        usage = llm._extract_anthropic_token_usage(mock_response)
+        assert usage["input_tokens"] == 50
+        assert usage["output_tokens"] == 25
+        assert usage["total_tokens"] == 75