fix(mcp): delete per-user env vars with their server and document POST replace semantics

litellm/proxy/_experimental/mcp_server/db.py

@@ -469,6 +469,9 @@ async def delete_mcp_server(
     """
     Delete the mcp server from the db by server_id
 
+    Also removes any per-user env var rows for the server, which have no FK
+    cascade, so deleting a server never leaves orphaned credential rows behind.
+
     Returns the deleted mcp server record if it exists, otherwise None
     """
     deleted_server = await prisma_client.db.litellm_mcpservertable.delete(
@@ -476,6 +479,10 @@ async def delete_mcp_server(
             "server_id": server_id,
         },
     )
+    if deleted_server is not None:
+        await prisma_client.db.litellm_mcpuserenvvars.delete_many(
+            where={"server_id": server_id}
+        )
     return deleted_server
 
 

litellm/proxy/management_endpoints/mcp_management_endpoints.py

@@ -2273,7 +2273,12 @@ if MCP_AVAILABLE:
 
     @router.post(
         "/server/{server_id}/user-env-vars",
-        description="Store the calling user's per-user MCP env var values for this server.",
+        description=(
+            "Store the calling user's per-user MCP env var values for this "
+            "server. This fully replaces any previously stored values: a "
+            "variable omitted from the request (or sent empty) is cleared, "
+            "not preserved. Send the complete set you want retained."
+        ),
         dependencies=[Depends(user_api_key_auth)],
         response_model=MCPUserEnvVarsStatus,
     )

tests/test_litellm/proxy/_experimental/mcp_server/test_mcp_env_vars.py

@@ -673,6 +673,40 @@ async def test_delete_user_env_vars_is_idempotent_delete_many():
     assert call.kwargs["where"] == {"user_id": "alice", "server_id": "srv-1"}
 
 
+@pytest.mark.asyncio
+async def test_delete_mcp_server_removes_orphaned_user_env_vars():
+    """Deleting a server must also drop every user's per-user env var rows for
+    it; there is no FK cascade, so skipping this leaves orphaned credentials."""
+    from unittest.mock import AsyncMock
+
+    from litellm.proxy._experimental.mcp_server.db import delete_mcp_server
+
+    prisma = _mock_env_vars_prisma()
+    prisma.db.litellm_mcpservertable.delete = AsyncMock(return_value=object())
+
+    await delete_mcp_server(prisma, "srv-1")
+
+    prisma.db.litellm_mcpuserenvvars.delete_many.assert_awaited_once()
+    call = prisma.db.litellm_mcpuserenvvars.delete_many.call_args
+    assert call.kwargs["where"] == {"server_id": "srv-1"}
+
+
+@pytest.mark.asyncio
+async def test_delete_mcp_server_skips_env_var_cleanup_when_server_missing():
+    """A no-op delete (server not found) must not touch the env var table."""
+    from unittest.mock import AsyncMock
+
+    from litellm.proxy._experimental.mcp_server.db import delete_mcp_server
+
+    prisma = _mock_env_vars_prisma()
+    prisma.db.litellm_mcpservertable.delete = AsyncMock(return_value=None)
+
+    result = await delete_mcp_server(prisma, "srv-1")
+
+    assert result is None
+    prisma.db.litellm_mcpuserenvvars.delete_many.assert_not_awaited()
+
+
 # ── DB helpers: global env vars encrypted at rest ─────────────────────────