fix(image_edit): forward litellm_params to validate_environment for Vertex AI credentials

When aimage_edit or image_edit was called with Vertex AI Gemini/Imagen models
via YAML-style config (vertex_project / vertex_credentials in proxy YAML),
the credentials were dropped during handler-to-config plumbing, causing
fallback to Application Default Credentials and DefaultCredentialsError.

Root cause: image_edit_handler and async_image_edit_handler did not pass
litellm_params to validate_environment, unlike image_generation_handler.

Fixes:
1. Widen BaseImageEditConfig.validate_environment signature to accept
   litellm_params and api_base (optional kwargs).
2. Forward dict(litellm_params) and litellm_params.api_base from both
   sync and async image_edit handlers to validate_environment.
3. Update VertexAIImagenImageEditConfig.validate_environment to read
   vertex_ai_project/vertex_ai_credentials from litellm_params first,
   matching Gemini config pattern (secondary latent bug fix).
4. Widen all image-edit config override signatures to match base.

Made-with: Cursor

litellm/llms/azure/image_edit/transformation.py

@@ -14,6 +14,8 @@ class AzureImageEditConfig(OpenAIImageEditConfig):
         headers: dict,
         model: str,
         api_key: Optional[str] = None,
+        litellm_params: Optional[dict] = None,
+        api_base: Optional[str] = None,
     ) -> dict:
         api_key = (
             api_key

litellm/llms/azure_ai/image_edit/flux2_transformation.py

@@ -65,6 +65,8 @@ class AzureFoundryFlux2ImageEditConfig(OpenAIImageEditConfig):
         headers: dict,
         model: str,
         api_key: Optional[str] = None,
+        litellm_params: Optional[dict] = None,
+        api_base: Optional[str] = None,
     ) -> dict:
         """
         Validate Azure AI Foundry environment and set up authentication

litellm/llms/azure_ai/image_edit/transformation.py

@@ -25,6 +25,8 @@ class AzureFoundryFluxImageEditConfig(OpenAIImageEditConfig):
         headers: dict,
         model: str,
         api_key: Optional[str] = None,
+        litellm_params: Optional[dict] = None,
+        api_base: Optional[str] = None,
     ) -> dict:
         """
         Validate Azure AI Foundry environment and set up authentication

litellm/llms/base_llm/image_edit/transformation.py

@@ -67,6 +67,8 @@ class BaseImageEditConfig(ABC):
         headers: dict,
         model: str,
         api_key: Optional[str] = None,
+        litellm_params: Optional[dict] = None,
+        api_base: Optional[str] = None,
     ) -> dict:
         return {}
 

litellm/llms/bedrock/image_edit/amazon_nova_canvas_image_edit_transformation.py

@@ -483,6 +483,8 @@ class BedrockAmazonNovaCanvasImageEditConfig(BaseImageEditConfig):
         headers: dict,
         model: str,
         api_key: Optional[str] = None,
+        litellm_params: Optional[dict] = None,
+        api_base: Optional[str] = None,
     ) -> dict:
         if headers is None:
             headers = {}

litellm/llms/bedrock/image_edit/stability_transformation.py

@@ -372,6 +372,8 @@ class BedrockStabilityImageEditConfig(BaseImageEditConfig):
         headers: dict,
         model: str,
         api_key: Optional[str] = None,
+        litellm_params: Optional[dict] = None,
+        api_base: Optional[str] = None,
     ) -> dict:
         """
         Validate environment for Bedrock Stability image edit.

litellm/llms/black_forest_labs/image_edit/transformation.py

@@ -123,6 +123,8 @@ class BlackForestLabsImageEditConfig(BaseImageEditConfig):
         headers: dict,
         model: str,
         api_key: Optional[str] = None,
+        litellm_params: Optional[dict] = None,
+        api_base: Optional[str] = None,
     ) -> dict:
         """
         Validate environment and set up headers for Black Forest Labs.

litellm/llms/custom_httpx/llm_http_handler.py

@@ -5216,6 +5216,8 @@ class BaseLLMHTTPHandler:
             api_key=litellm_params.api_key,
             headers=image_edit_optional_request_params.get("extra_headers", {}) or {},
             model=model,
+            litellm_params=dict(litellm_params),
+            api_base=litellm_params.api_base,
         )
 
         if extra_headers:
@@ -5312,6 +5314,8 @@ class BaseLLMHTTPHandler:
             api_key=litellm_params.api_key,
             headers=image_edit_optional_request_params.get("extra_headers", {}) or {},
             model=model,
+            litellm_params=dict(litellm_params),
+            api_base=litellm_params.api_base,
         )
 
         if extra_headers:

litellm/llms/gemini/image_edit/transformation.py

@@ -54,6 +54,8 @@ class GeminiImageEditConfig(BaseImageEditConfig):
         headers: dict,
         model: str,
         api_key: Optional[str] = None,
+        litellm_params: Optional[dict] = None,
+        api_base: Optional[str] = None,
     ) -> dict:
         final_api_key: Optional[str] = api_key or get_secret_str("GEMINI_API_KEY")
         if not final_api_key:

litellm/llms/litellm_proxy/image_edit/transformation.py

@@ -8,7 +8,12 @@ class LiteLLMProxyImageEditConfig(OpenAIImageEditConfig):
     """Configuration for image edit requests routed through LiteLLM Proxy."""
 
     def validate_environment(
-        self, headers: dict, model: str, api_key: Optional[str] = None
+        self,
+        headers: dict,
+        model: str,
+        api_key: Optional[str] = None,
+        litellm_params: Optional[dict] = None,
+        api_base: Optional[str] = None,
     ) -> dict:
         api_key = api_key or get_secret_str("LITELLM_PROXY_API_KEY")
         headers.update({"Authorization": f"Bearer {api_key}"})

litellm/llms/openai/image_edit/transformation.py

@@ -165,6 +165,8 @@ class OpenAIImageEditConfig(BaseImageEditConfig):
         headers: dict,
         model: str,
         api_key: Optional[str] = None,
+        litellm_params: Optional[dict] = None,
+        api_base: Optional[str] = None,
     ) -> dict:
         api_key = (
             api_key

litellm/llms/openrouter/image_edit/transformation.py

@@ -116,6 +116,8 @@ class OpenRouterImageEditConfig(BaseImageEditConfig):
         headers: dict,
         model: str,
         api_key: Optional[str] = None,
+        litellm_params: Optional[dict] = None,
+        api_base: Optional[str] = None,
     ) -> dict:
         api_key = api_key or litellm.api_key or get_secret_str("OPENROUTER_API_KEY")
         if not api_key:

litellm/llms/recraft/image_edit/transformation.py

@@ -81,6 +81,8 @@ class RecraftImageEditConfig(BaseImageEditConfig):
         headers: dict,
         model: str,
         api_key: Optional[str] = None,
+        litellm_params: Optional[dict] = None,
+        api_base: Optional[str] = None,
     ) -> dict:
         final_api_key: Optional[str] = api_key or get_secret_str("RECRAFT_API_KEY")
         if not final_api_key:

litellm/llms/stability/image_edit/transformations.py

@@ -149,6 +149,8 @@ class StabilityImageEditConfig(BaseImageEditConfig):
         headers: dict,
         model: str,
         api_key: Optional[str] = None,
+        litellm_params: Optional[dict] = None,
+        api_base: Optional[str] = None,
     ) -> dict:
         """
         Validate environment and set up headers for Stability AI.

litellm/llms/vertex_ai/image_edit/vertex_imagen_transformation.py

@@ -103,10 +103,24 @@ class VertexAIImagenImageEditConfig(BaseImageEditConfig, VertexLLM):
         headers: dict,
         model: str,
         api_key: Optional[str] = None,
+        litellm_params: Optional[dict] = None,
+        api_base: Optional[str] = None,
     ) -> dict:
         headers = headers or {}
-        vertex_project = self._resolve_vertex_project()
-        vertex_credentials = self._resolve_vertex_credentials()
+        litellm_params = litellm_params or {}
+
+        _api_base = litellm_params.get("api_base") or api_base
+        if _api_base is not None:
+            return headers
+
+        vertex_project = (
+            self.safe_get_vertex_ai_project(litellm_params)
+            or self._resolve_vertex_project()
+        )
+        vertex_credentials = (
+            self.safe_get_vertex_ai_credentials(litellm_params)
+            or self._resolve_vertex_credentials()
+        )
         access_token, _ = self._ensure_access_token(
             credentials=vertex_credentials,
             project_id=vertex_project,

tests/test_litellm/images/test_image_edit_utils.py

@@ -1,4 +1,4 @@
-from typing import Any, Dict, List
+from typing import Any, Dict, List, Optional
 from unittest.mock import MagicMock, patch
 
 import pytest
@@ -26,7 +26,12 @@ class MockImageEditConfig(BaseImageEditConfig):
         return "https://example.com/api"
 
     def validate_environment(
-        self, headers: dict, model: str, api_key: str = None
+        self,
+        headers: dict,
+        model: str,
+        api_key: str = None,
+        litellm_params: Optional[dict] = None,
+        api_base: Optional[str] = None,
     ) -> dict:
         return headers