(feat) pass through llm endpoints - add PATCH support (vertex context caching requires for update ops) (#6924)

* add PATCH for pass through endpoints

* test_pass_through_routes_support_all_methods

litellm/proxy/pass_through_endpoints/llm_passthrough_endpoints.py

@@ -56,7 +56,7 @@ def create_request_copy(request: Request):
 
 @router.api_route(
     "/gemini/{endpoint:path}",
-    methods=["GET", "POST", "PUT", "DELETE"],
+    methods=["GET", "POST", "PUT", "DELETE", "PATCH"],
     tags=["Google AI Studio Pass-through", "pass-through"],
 )
 async def gemini_proxy_route(
@@ -122,7 +122,7 @@ async def gemini_proxy_route(
 
 @router.api_route(
     "/cohere/{endpoint:path}",
-    methods=["GET", "POST", "PUT", "DELETE"],
+    methods=["GET", "POST", "PUT", "DELETE", "PATCH"],
     tags=["Cohere Pass-through", "pass-through"],
 )
 async def cohere_proxy_route(
@@ -171,7 +171,7 @@ async def cohere_proxy_route(
 
 @router.api_route(
     "/anthropic/{endpoint:path}",
-    methods=["GET", "POST", "PUT", "DELETE"],
+    methods=["GET", "POST", "PUT", "DELETE", "PATCH"],
     tags=["Anthropic Pass-through", "pass-through"],
 )
 async def anthropic_proxy_route(
@@ -224,7 +224,7 @@ async def anthropic_proxy_route(
 
 @router.api_route(
     "/bedrock/{endpoint:path}",
-    methods=["GET", "POST", "PUT", "DELETE"],
+    methods=["GET", "POST", "PUT", "DELETE", "PATCH"],
     tags=["Bedrock Pass-through", "pass-through"],
 )
 async def bedrock_proxy_route(
@@ -305,7 +305,7 @@ async def bedrock_proxy_route(
 
 @router.api_route(
     "/azure/{endpoint:path}",
-    methods=["GET", "POST", "PUT", "DELETE"],
+    methods=["GET", "POST", "PUT", "DELETE", "PATCH"],
     tags=["Azure Pass-through", "pass-through"],
 )
 async def azure_proxy_route(

litellm/proxy/vertex_ai_endpoints/langfuse_endpoints.py

@@ -60,7 +60,7 @@ def create_request_copy(request: Request):
 
 @router.api_route(
     "/langfuse/{endpoint:path}",
-    methods=["GET", "POST", "PUT", "DELETE"],
+    methods=["GET", "POST", "PUT", "DELETE", "PATCH"],
     tags=["Langfuse Pass-through", "pass-through"],
 )
 async def langfuse_proxy_route(

litellm/proxy/vertex_ai_endpoints/vertex_endpoints.py

@@ -143,12 +143,14 @@ def construct_target_url(
 
 @router.api_route(
     "/vertex-ai/{endpoint:path}",
-    methods=["GET", "POST", "PUT", "DELETE"],
+    methods=["GET", "POST", "PUT", "DELETE", "PATCH"],
     tags=["Vertex AI Pass-through", "pass-through"],
     include_in_schema=False,
 )
 @router.api_route(
-    "/vertex_ai/{endpoint:path}", methods=["GET", "POST", "PUT", "DELETE"], tags=["Vertex AI Pass-through", "pass-through"]
+    "/vertex_ai/{endpoint:path}",
+    methods=["GET", "POST", "PUT", "DELETE", "PATCH"],
+    tags=["Vertex AI Pass-through", "pass-through"],
 )
 async def vertex_proxy_route(
     endpoint: str,

tests/pass_through_unit_tests/test_pass_through_unit_tests.py

@@ -10,6 +10,8 @@ sys.path.insert(
 )  # Adds the parent directory to the system path
 
 import fastapi
+from fastapi import FastAPI
+from fastapi.routing import APIRoute
 import httpx
 import pytest
 import litellm
@@ -320,3 +322,36 @@ async def test_pass_through_request_logging_failure_with_stream(
         assert content is not None
         if isinstance(content, bytes):
             assert len(content) > 0
+
+
+def test_pass_through_routes_support_all_methods():
+    """
+    Test that all pass-through routes support GET, POST, PUT, DELETE, PATCH methods
+    """
+    # Import the routers
+    from litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints import (
+        router as llm_router,
+    )
+    from litellm.proxy.vertex_ai_endpoints.vertex_endpoints import (
+        router as vertex_router,
+    )
+
+    # Expected HTTP methods
+    expected_methods = {"GET", "POST", "PUT", "DELETE", "PATCH"}
+
+    # Function to check routes in a router
+    def check_router_methods(router):
+        for route in router.routes:
+            if isinstance(route, APIRoute):
+                # Get path and methods for this route
+                path = route.path
+                methods = set(route.methods)
+                print("supported methods for route", path, "are", methods)
+                # Assert all expected methods are supported
+                assert (
+                    methods == expected_methods
+                ), f"Route {path} does not support all methods. Supported: {methods}, Expected: {expected_methods}"
+
+    # Check both routers
+    check_router_methods(llm_router)
+    check_router_methods(vertex_router)