fix: respect vertex ai location settings

- Add location parameter to LLM class
- Add test for vertex ai location setting
- Update documentation

Fixes #2141

Co-Authored-By: Joe Moura <joao@crewai.com>

src/crewai/llm.py

@@ -117,9 +117,19 @@ def suppress_warnings():
 
 
 class LLM:
+    """A wrapper around LiteLLM providing a unified interface for various LLM providers.
+
+    Args:
+        model (str): The identifier of the LLM model to use
+        location (Optional[str]): Optional location for provider-specific settings (e.g., Vertex AI region)
+        timeout (Optional[Union[float, int]]): Maximum time to wait for the model response
+        temperature (Optional[float]): Controls randomness in the model's output
+        top_p (Optional[float]): Controls diversity of the model's output
+    """
     def __init__(
         self,
         model: str,
+        location: Optional[str] = None,
         timeout: Optional[Union[float, int]] = None,
         temperature: Optional[float] = None,
         top_p: Optional[float] = None,
@@ -143,6 +153,7 @@ class LLM:
         **kwargs,
     ):
         self.model = model
+        self.location = location
         self.timeout = timeout
         self.temperature = temperature
         self.top_p = top_p
@@ -166,6 +177,10 @@ class LLM:
         self.additional_params = kwargs
         self.is_anthropic = self._is_anthropic_model(model)
 
+        # Set vertex location if provided for vertex models
+        if self.location and ("vertex" in self.model.lower() or self.model.startswith("gemini-")):
+            litellm.vertex_location = self.location
+
         litellm.drop_params = True
 
         # Normalize self.stop to always be a List[str]

tests/llm_test.py

@@ -3,6 +3,7 @@ from time import sleep
 from unittest.mock import MagicMock, patch
 
 import pytest
+import litellm
 from pydantic import BaseModel
 
 from crewai.agents.agent_builder.utilities.base_token_process import TokenProcess
@@ -12,6 +13,21 @@ from crewai.utilities.token_counter_callback import TokenCalcHandler
 
 
 # TODO: This test fails without print statement, which makes me think that something is happening asynchronously that we need to eventually fix and dive deeper into at a later date
+@pytest.mark.vcr(filter_headers=["authorization"])
+def test_vertex_ai_location():
+    """Test that Vertex AI location setting is respected."""
+    location = "europe-west4"
+    llm = LLM(
+        model="vertex_ai/gemini-2.0-flash",
+        location=location,
+    )
+    
+    # Verify location is set correctly
+    assert litellm.vertex_location == location
+    
+    # Reset location after test
+    litellm.vertex_location = None
+
 @pytest.mark.vcr(filter_headers=["authorization"])
 def test_llm_callback_replacement():
     llm1 = LLM(model="gpt-4o-mini")