feat(proxy): add NO_OPENAPI env var to disable /openapi.json endpoint (#25696)

* feat(proxy): add NO_OPENAPI env var to disable /openapi.json endpoint - Fixes #25538

* test(proxy): add tests for _get_openapi_url

---------

Co-authored-by: Progressive-engg <lov.kumari55@gmail.com>

litellm/proxy/proxy_server.py

@@ -496,6 +496,7 @@ from litellm.proxy.utils import (
     _get_openapi_url,
     _get_projected_spend_over_limit,
     _get_redoc_url,
+    _get_openapi_url,
     _is_projected_spend_over_limit,
     _is_valid_team_configs,
     get_custom_url,

litellm/proxy/utils.py

@@ -5367,6 +5367,22 @@ def _get_docs_url() -> Optional[str]:
 
     return "/"
 
+def _get_openapi_url() -> Optional[str]:
+    """
+    Get the OpenAPI JSON URL from the environment variables.
+
+    - If OPENAPI_URL is set, return it.
+    - If NO_OPENAPI is True, return None.
+    - Otherwise, default to "/openapi.json".
+    """
+    if openapi_url := os.getenv("OPENAPI_URL"):
+        return openapi_url
+
+    if str_to_bool(os.getenv("NO_OPENAPI")) is True:
+        return None
+
+    return "/openapi.json"
+
 
 def handle_exception_on_proxy(e: Exception) -> ProxyException:
     """

tests/proxy_unit_tests/test_proxy_utils.py

@@ -10,7 +10,7 @@ import pytest
 from fastapi import Request
 from starlette.datastructures import State
 
-from litellm.proxy.utils import _get_docs_url, _get_redoc_url
+from litellm.proxy.utils import _get_docs_url, _get_openapi_url, _get_redoc_url
 
 sys.path.insert(
     0, os.path.abspath("../..")
@@ -735,6 +735,30 @@ def test_get_docs_url(env_vars, expected_url):
     result = _get_docs_url()
     assert result == expected_url
 
+@pytest.mark.parametrize(
+    "env_vars, expected_url",
+    [
+        ({}, "/openapi.json"),  # default case
+        ({"OPENAPI_URL": "/custom-openapi.json"}, "/custom-openapi.json"),  # custom URL
+        (
+            {"OPENAPI_URL": "https://example.com/openapi.json"},
+            "https://example.com/openapi.json",
+        ),  # full URL
+        ({"NO_OPENAPI": "True"}, None),  # openapi disabled
+    ],
+)
+def test_get_openapi_url(env_vars, expected_url):
+    # Clear relevant environment variables
+    for key in ["OPENAPI_URL", "NO_OPENAPI"]:
+        os.environ.pop(key, None)
+
+    # Set test environment variables
+    for key, value in env_vars.items():
+        os.environ[key] = value
+
+    result = _get_openapi_url()
+    assert result == expected_url
+
 
 @pytest.mark.parametrize(
     "request_tags, tags_to_add, expected_tags",