add NO_OPENAPI env var to disable /openapi.json endpoint (#25547)

docs/my-website/docs/proxy/config_settings.md

@@ -914,6 +914,7 @@ router_settings:
 | MODEL_COST_MAP_MAX_SHRINK_RATIO | Maximum allowed shrinkage ratio when validating a fetched model cost map against the local backup. Rejects the fetched map if it is smaller than this fraction of the backup. Default is 0.5
 | MODEL_COST_MAP_MIN_MODEL_COUNT | Minimum number of models a fetched cost map must contain to be considered valid. Default is 50
 | NO_DOCS | Flag to disable Swagger UI documentation
+| NO_OPENAPI | Flag to disable the /openapi.json endpoint
 | NO_REDOC | Flag to disable Redoc documentation
 | NO_PROXY | List of addresses to bypass proxy
 | NON_LLM_CONNECTION_TIMEOUT | Timeout in seconds for non-LLM service connections. Default is 15

litellm/proxy/proxy_server.py

@@ -493,6 +493,7 @@ from litellm.proxy.utils import (
     ProxyUpdateSpend,
     _cache_user_row,
     _get_docs_url,
+    _get_openapi_url,
     _get_projected_spend_over_limit,
     _get_redoc_url,
     _is_projected_spend_over_limit,
@@ -1000,6 +1001,7 @@ async def proxy_startup_event(app: FastAPI):  # noqa: PLR0915
 app = FastAPI(
     docs_url=_get_docs_url(),
     redoc_url=_get_redoc_url(),
+    openapi_url=_get_openapi_url(),
     title=_title,
     description=_description,
     version=version,

litellm/proxy/utils.py

@@ -5321,6 +5321,19 @@ def get_error_message_str(e: Exception) -> str:
     return error_message
 
 
+def _get_openapi_url() -> Optional[str]:
+    """
+    Get the OpenAPI schema URL from the environment variables.
+
+    - If NO_OPENAPI is True, return None.
+    - Otherwise, default to "/openapi.json".
+    """
+    if str_to_bool(os.getenv("NO_OPENAPI")) is True:
+        return None
+
+    return "/openapi.json"
+
+
 def _get_redoc_url() -> Optional[str]:
     """
     Get the Redoc URL from the environment variables.

tests/test_litellm/proxy/test_utils.py

@@ -0,0 +1,22 @@
+import pytest
+
+from litellm.proxy.utils import _get_openapi_url
+
+
+@pytest.mark.parametrize(
+    "env_vars, expected_url",
+    [
+        ({}, "/openapi.json"),  # default case
+        ({"NO_OPENAPI": "True"}, None),  # OpenAPI disabled
+    ],
+)
+def test_get_openapi_url(monkeypatch, env_vars, expected_url):
+    # Clear relevant environment variables
+    monkeypatch.delenv("NO_OPENAPI", raising=False)
+
+    # Set test environment variables
+    for key, value in env_vars.items():
+        monkeypatch.setenv(key, value)
+
+    result = _get_openapi_url()
+    assert result == expected_url