diff --git a/.circleci/config.yml b/.circleci/config.yml
index 133a7184f9..e03d108628 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -1153,7 +1153,7 @@ jobs:
             pip install "pytest-asyncio==0.21.1"
             pip install "respx==0.22.0"
             pip install "pydantic==2.10.2"
-            pip install "mcp==1.10.1"
+            pip install "mcp==1.21.2"
       # Run pytest and generate JUnit XML report
       - run:
           name: Run tests
diff --git a/tests/mcp_tests/mcp_server.py b/tests/mcp_tests/mcp_server.py
index 99a67edd02..bc6accbb72 100644
--- a/tests/mcp_tests/mcp_server.py
+++ b/tests/mcp_tests/mcp_server.py
@@ -1,9 +1,33 @@
 # math_server.py
+import argparse
+import os
+
 from mcp.server.fastmcp import FastMCP
 
 mcp = FastMCP("Math")
 
 
+def _parse_args() -> argparse.Namespace:
+    parser = argparse.ArgumentParser(description="MCP math test server")
+    parser.add_argument(
+        "--transport",
+        default=os.getenv("MCP_TRANSPORT", "stdio"),
+        help="Transport to use (stdio or http)",
+    )
+    parser.add_argument(
+        "--host",
+        default=os.getenv("MCP_HOST", "127.0.0.1"),
+        help="Host to bind when serving over HTTP",
+    )
+    parser.add_argument(
+        "--port",
+        type=int,
+        default=int(os.getenv("MCP_PORT", "0")),
+        help="Port to bind when serving over HTTP",
+    )
+    return parser.parse_args()
+
+
 @mcp.tool()
 def add(a: int, b: int) -> int:
     """Add two numbers"""
@@ -16,5 +40,24 @@ def multiply(a: int, b: int) -> int:
     return a * b
 
 
+def main() -> None:
+    args = _parse_args()
+    transport = (args.transport or "stdio").lower()
+
+    if transport == "stdio":
+        mcp.run(transport="stdio")
+        return
+
+    if transport in {"http", "streamable_http", "streamable-http"}:
+        if args.port <= 0:
+            raise ValueError("HTTP transport requires a valid --port value")
+        mcp.settings.host = args.host
+        mcp.settings.port = args.port
+        mcp.run(transport="streamable-http")
+        return
+
+    raise ValueError(f"Unsupported transport: {transport}")
+
+
 if __name__ == "__main__":
-    mcp.run(transport="stdio")
+    main()
diff --git a/tests/mcp_tests/test_configs/test_config_mcp_e2e.yaml b/tests/mcp_tests/test_configs/test_config_mcp_e2e.yaml
new file mode 100644
index 0000000000..37d5359e3c
--- /dev/null
+++ b/tests/mcp_tests/test_configs/test_config_mcp_e2e.yaml
@@ -0,0 +1,23 @@
+general_settings:
+  master_key: sk-1234
+
+litellm_settings:
+  drop_params: true
+
+model_list:
+  - model_name: openai-gpt-4o-mini
+    litellm_params:
+      model: gpt-4o-mini
+  - model_name: anthropic-claude-haiku-4-5
+    litellm_params:
+      model: anthropic/claude-haiku-4-5
+
+mcp_servers:
+  math_stdio:
+    transport: stdio
+    command: python3
+    args:
+      - tests/mcp_tests/mcp_server.py
+  math_streamable_http:
+    transport: http
+    url: http://127.0.0.1:0/mcp
diff --git a/tests/mcp_tests/test_mcp_server.py b/tests/mcp_tests/test_mcp_server.py
index 66dd2bdc6b..e8a1231c6f 100644
--- a/tests/mcp_tests/test_mcp_server.py
+++ b/tests/mcp_tests/test_mcp_server.py
@@ -1001,34 +1001,39 @@ async def test_mcp_server_manager_access_groups_from_config():
         MCPRequestHandler,
     )
 
-    # Patch global_mcp_server_manager for this test
+    # Patch global_mcp_server_manager for this test and restore afterwards to
+    # avoid leaking state into other tests (e.g. the proxy MCP e2e suite).
     import litellm.proxy._experimental.mcp_server.mcp_server_manager as mcp_server_manager_mod
 
+    original_manager = mcp_server_manager_mod.global_mcp_server_manager
     mcp_server_manager_mod.global_mcp_server_manager = test_manager
-    # Should find config_server for group-a, both for group-b, other_server for group-c
-    import asyncio
+    try:
+        # Should find config_server for group-a, both for group-b, other_server for group-c
+        import asyncio
 
-    server_ids_a = await MCPRequestHandler._get_mcp_servers_from_access_groups([
-        "group-a"
-    ])
-    server_ids_b = await MCPRequestHandler._get_mcp_servers_from_access_groups([
-        "group-b"
-    ])
-    server_ids_c = await MCPRequestHandler._get_mcp_servers_from_access_groups([
-        "group-c"
-    ])
-    assert any(config_server.server_id == sid for sid in server_ids_a)
-    assert set(server_ids_b) == set(
-        [
-            s.server_id
+        server_ids_a = await MCPRequestHandler._get_mcp_servers_from_access_groups([
+            "group-a"
+        ])
+        server_ids_b = await MCPRequestHandler._get_mcp_servers_from_access_groups([
+            "group-b"
+        ])
+        server_ids_c = await MCPRequestHandler._get_mcp_servers_from_access_groups([
+            "group-c"
+        ])
+        assert any(config_server.server_id == sid for sid in server_ids_a)
+        assert set(server_ids_b) == set(
+            [
+                s.server_id
+                for s in test_manager.config_mcp_servers.values()
+                if "group-b" in s.access_groups
+            ]
+        )
+        assert any(
+            s.name == "other_server" and s.server_id in server_ids_c
             for s in test_manager.config_mcp_servers.values()
-            if "group-b" in s.access_groups
-        ]
-    )
-    assert any(
-        s.name == "other_server" and s.server_id in server_ids_c
-        for s in test_manager.config_mcp_servers.values()
-    )
+        )
+    finally:
+        mcp_server_manager_mod.global_mcp_server_manager = original_manager
 
 
 async def test_mcp_server_manager_config_integration_with_database():
diff --git a/tests/mcp_tests/test_proxy_mcp_e2e.py b/tests/mcp_tests/test_proxy_mcp_e2e.py
new file mode 100644
index 0000000000..2b8cde5471
--- /dev/null
+++ b/tests/mcp_tests/test_proxy_mcp_e2e.py
@@ -0,0 +1,236 @@
+import asyncio
+import os
+import socket
+import subprocess
+import sys
+import threading
+import time
+import typing
+from pathlib import Path
+
+import pytest
+import uvicorn
+import yaml
+from mcp import ClientSession
+from mcp.client.streamable_http import streamablehttp_client
+
+from litellm.proxy.proxy_server import (
+    app as proxy_app,
+    cleanup_router_config_variables,
+    initialize,
+)
+
+
+CONFIG_TEMPLATE_PATH = Path("tests/mcp_tests/test_configs/test_config_mcp_e2e.yaml")
+MCP_SERVER_SCRIPT = Path("tests/mcp_tests/mcp_server.py")
+PROJECT_ROOT = Path(__file__).resolve().parents[2]
+PROXY_START_TIMEOUT = 30
+
+
+PROXY_AUTHORIZATION_HEADER = "Bearer sk-1234"
+
+
+@pytest.fixture(scope="session", autouse=True)
+def _clear_proxy_database_env() -> typing.Iterator[None]:
+    """Ensure local proxy DB settings don't leak into tests."""
+    mp = pytest.MonkeyPatch()
+    mp.delenv("DATABASE_URL", raising=False)
+    try:
+        yield
+    finally:
+        mp.undo()
+
+
+def _initialize_proxy(config_path: str) -> None:
+    cleanup_router_config_variables()
+    asyncio.run(initialize(config=config_path, debug=True))
+
+
+def _start_proxy_server(config_path: str) -> tuple[str, uvicorn.Server, threading.Thread, socket.socket]:
+    _initialize_proxy(config_path)
+
+    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    sock.bind(("127.0.0.1", 0))
+    host, port = sock.getsockname()
+
+    config = uvicorn.Config(proxy_app, host=host, port=port, log_level="warning")
+    server = uvicorn.Server(config)
+
+    def _run() -> None:
+        loop = asyncio.new_event_loop()
+        asyncio.set_event_loop(loop)
+        loop.run_until_complete(server.serve(sockets=[sock]))
+
+    thread = threading.Thread(target=_run, daemon=True)
+    thread.start()
+
+    start_time = time.time()
+    while not server.started:
+        if not thread.is_alive():
+            raise RuntimeError("Proxy server failed to start")
+        if time.time() - start_time > PROXY_START_TIMEOUT:
+            raise TimeoutError("Proxy server did not start in time")
+        time.sleep(0.05)
+
+    return f"http://{host}:{port}", server, thread, sock
+
+
+@pytest.fixture(scope="session")
+def math_streamable_http_server() -> str:
+    host = "127.0.0.1"
+    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
+        sock.bind((host, 0))
+        _, port = sock.getsockname()
+
+    cmd = [
+        sys.executable,
+        str(MCP_SERVER_SCRIPT),
+        "--transport",
+        "http",
+        "--host",
+        host,
+        "--port",
+        str(port),
+    ]
+
+    env = os.environ.copy()
+    server_process = subprocess.Popen(
+        cmd,
+        cwd=str(PROJECT_ROOT),
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+    )
+
+    start_time = time.time()
+    while True:
+        if server_process.poll() is not None:
+            stdout, stderr = server_process.communicate()
+            raise RuntimeError(
+                f"Streamable HTTP MCP server exited early.\nSTDOUT: {stdout.decode()}\nSTDERR: {stderr.decode()}"
+            )
+        try:
+            with socket.create_connection((host, port), timeout=0.1):
+                break
+        except OSError:
+            if time.time() - start_time > PROXY_START_TIMEOUT:
+                server_process.terminate()
+                raise TimeoutError("Streamable HTTP MCP server did not start in time")
+            time.sleep(0.05)
+
+    yield f"http://{host}:{port}"
+
+    server_process.terminate()
+    try:
+        server_process.wait(timeout=5)
+    except subprocess.TimeoutExpired:
+        server_process.kill()
+
+
+@pytest.fixture(scope="session")
+def proxy_server_url(
+    tmp_path_factory: pytest.TempPathFactory, math_streamable_http_server: str
+):
+    config_dir = tmp_path_factory.mktemp("mcp_e2e")
+    config_path = config_dir / "config.yaml"
+    config = yaml.safe_load(CONFIG_TEMPLATE_PATH.read_text())
+    config["mcp_servers"]["math_streamable_http"][
+        "url"
+    ] = f"{math_streamable_http_server}/mcp"
+    config_path.write_text(yaml.safe_dump(config))
+
+    server_url, server, thread, sock = _start_proxy_server(str(config_path))
+
+    yield server_url
+
+    server.should_exit = True
+    thread.join(timeout=10)
+    sock.close()
+
+
+class TestProxyMcpSimpleConnections:
+    @pytest.mark.asyncio
+    async def test_proxy_mcp_stdio_roundtrip(self, proxy_server_url: str) -> None:
+        async with asyncio.timeout(20):
+            async with streamablehttp_client(
+                url=f"{proxy_server_url}/mcp",
+                headers={
+                    "Authorization": PROXY_AUTHORIZATION_HEADER,
+                    "x-mcp-servers": "math_stdio",
+                },
+            ) as (read, write, _get_session_id):
+                async with ClientSession(read, write) as session:
+                    await session.initialize()
+                    tools_result = await session.list_tools()
+                    assert any(tool.name.endswith("add") for tool in tools_result.tools)
+
+                    result = await session.call_tool(
+                        "add", arguments={"a": 3, "b": 4}
+                    )
+                    assert result.content
+                    first_content = result.content[0]
+                    text = getattr(first_content, "text", None)
+                    assert text == "7"
+
+    @pytest.mark.asyncio
+    async def test_proxy_mcp_streamable_http_roundtrip(
+        self, proxy_server_url: str
+    ) -> None:
+        async with asyncio.timeout(20):
+            async with streamablehttp_client(
+                url=f"{proxy_server_url}/mcp",
+                headers={
+                    "Authorization": PROXY_AUTHORIZATION_HEADER,
+                    "x-mcp-servers": "math_streamable_http",
+                },
+            ) as (read, write, _get_session_id):
+                async with ClientSession(read, write) as session:
+                    await session.initialize()
+                    tools_result = await session.list_tools()
+                    assert any(tool.name.endswith("add") for tool in tools_result.tools)
+
+                    result = await session.call_tool(
+                        "add", arguments={"a": 5, "b": 6}
+                    )
+                    assert result.content
+                    first_content = result.content[0]
+                    text = getattr(first_content, "text", None)
+                    assert text == "11"
+
+    @pytest.mark.asyncio
+    async def test_proxy_mcp_lists_all_servers_without_header(
+        self, proxy_server_url: str
+    ) -> None:
+        async with asyncio.timeout(20):
+            async with streamablehttp_client(
+                url=f"{proxy_server_url}/mcp",
+                headers={"Authorization": PROXY_AUTHORIZATION_HEADER},
+            ) as (read, write, _get_session_id):
+                async with ClientSession(read, write) as session:
+                    await session.initialize()
+                    tools_result = await session.list_tools()
+                    tool_names = {tool.name for tool in tools_result.tools}
+                    expected_tool_names = {
+                        "math_stdio-add",
+                        "math_stdio-multiply",
+                        "math_streamable_http-add",
+                        "math_streamable_http-multiply",
+                    }
+                    assert expected_tool_names <= tool_names
+
+                    async def _call_and_get_text(
+                        tool_name: str, *, a: int, b: int
+                    ) -> str | None:
+                        result = await session.call_tool(tool_name, arguments={"a": a, "b": b})
+                        assert result.content
+                        first_content = result.content[0]
+                        return getattr(first_content, "text", None)
+
+                    stdio_result = await _call_and_get_text(
+                        "math_stdio-add", a=2, b=3
+                    )
+                    streamable_result = await _call_and_get_text(
+                        "math_streamable_http-add", a=4, b=5
+                    )
+                    assert stdio_result == "5"
+                    assert streamable_result == "9"