From 3d5ca7ce3fcd81b6aec2f9c7d06ec592aa2f4959 Mon Sep 17 00:00:00 2001
From: Sisyphus <wangbin042@gmail.com>
Date: Mon, 31 Aug 2026 22:22:34 +0800
Subject: [PATCH] fix(mcp): avoid eager YAML dependency import

---
 .../proxy/_experimental/mcp_server/openapi_to_mcp_generator.py | 3 ++-
 pyproject.toml                                                 | 2 +-
 uv.lock                                                        | 2 --
 3 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/litellm/proxy/_experimental/mcp_server/openapi_to_mcp_generator.py b/litellm/proxy/_experimental/mcp_server/openapi_to_mcp_generator.py
index 23b34ade96e..179d9997750 100644
--- a/litellm/proxy/_experimental/mcp_server/openapi_to_mcp_generator.py
+++ b/litellm/proxy/_experimental/mcp_server/openapi_to_mcp_generator.py
@@ -13,7 +13,6 @@ from typing import Any, Final, TypedDict
 from urllib.parse import quote
 
 import httpx
-import yaml
 from typing_extensions import ReadOnly, Required
 
 from litellm.llms.custom_httpx.http_handler import MaskedHTTPStatusError
@@ -181,6 +180,8 @@ def _parse_openapi_spec(text: str) -> Mapping[str, Any]:
     try:
         parsed: Any = json.loads(text)
     except json.JSONDecodeError:
+        import yaml
+
         parsed = yaml.safe_load(text)
 
     if not isinstance(parsed, dict):
diff --git a/pyproject.toml b/pyproject.toml
index a41c7109701..e670b10547e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -123,7 +123,7 @@ utils = [
     "numpydoc>=1.8.0,<2.0",
 ]
 caching = ["diskcache>=5.6.3,<6.0"]
-mcp = ["mcp>=2.2.0,<3", "httpx2>=2.5.0,<3", "pydantic>=2.12.0,<3", "pyyaml>=6.0.3,<7.0"]
+mcp = ["mcp>=2.2.0,<3", "httpx2>=2.5.0,<3", "pydantic>=2.12.0,<3"]
 # Driver for the MongoDB Atlas vector store; Atlas Vector Search has no HTTP query API.
 # The floor is 4.9 because that is the release AsyncMongoClient landed in.
 # SAML SSO for the admin UI. python3-saml pulls in xmlsec/lxml, whose wheels
diff --git a/uv.lock b/uv.lock
index 0a5d1634a1f..a481ecb2a2c 100644
--- a/uv.lock
+++ b/uv.lock
@@ -4562,7 +4562,6 @@ mcp = [
     { name = "httpx2" },
     { name = "mcp" },
     { name = "pydantic" },
-    { name = "pyyaml" },
 ]
 mlflow = [
     { name = "mlflow" },
@@ -4841,7 +4840,6 @@ requires-dist = [
     { name = "python3-saml", marker = "extra == 'saml'", specifier = ">=1.16.0,<2.0" },
     { name = "pyyaml", specifier = ">=6.0.3,<7.0" },
     { name = "pyyaml", marker = "extra == 'cli'", specifier = ">=6.0.3,<7.0" },
-    { name = "pyyaml", marker = "extra == 'mcp'", specifier = ">=6.0.3,<7.0" },
     { name = "pyyaml", marker = "extra == 'proxy'", specifier = ">=6.0.3,<7.0" },
     { name = "redisvl", marker = "extra == 'extra-proxy'", specifier = ">=0.4.1,<1.0" },
     { name = "requests", marker = "extra == 'cli'", specifier = ">=2.32.0,<3.0" },