fix(ui): persist deletion of litellm params from the model edit JSON editor

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

litellm/proxy/management_endpoints/model_management_endpoints.py

@@ -511,15 +511,19 @@ def update_db_model(db_model: Deployment, updated_patch: updateDeployment) -> Pr
     # passes through (which today re-sends the OLD pricing on every save) cannot
     # silently undo a litellm_params clear via .update().
     #
-    # Restricted to SPECIAL_MODEL_INFO_PARAMS (input/output cost per token/character
-    # and cache read/write costs) so this path cannot be used to null out privileged
-    # model_info fields like team_id or access groups. SPECIAL_MODEL_INFO_PARAMS are
-    # mirrored between litellm_params and model_info by Deployment.__init__, so the
-    # clear propagates to both blobs.
+    # Any litellm_params field sent as an explicit null is removed from the stored
+    # params (PATCH semantics; the UI relies on this to persist deletions from the
+    # LiteLLM Params JSON editor). "model" is exempt since a deployment without a
+    # model is invalid. The model_info mirror is restricted to
+    # SPECIAL_MODEL_INFO_PARAMS (pricing fields mirrored between the two blobs by
+    # Deployment.__init__) so this path cannot null out privileged model_info
+    # fields like team_id or access groups.
     if updated_patch.litellm_params:
         for field in updated_patch.litellm_params.model_fields_set:
-            if field in SPECIAL_MODEL_INFO_PARAMS and getattr(updated_patch.litellm_params, field) is None:
-                merged_litellm_params.pop(field, None)
+            if field == "model" or getattr(updated_patch.litellm_params, field) is not None:
+                continue
+            merged_litellm_params.pop(field, None)
+            if field in SPECIAL_MODEL_INFO_PARAMS:
                 merged_model_info.pop(field, None)
     if updated_patch.model_info:
         for field in updated_patch.model_info.model_fields_set:

tests/test_litellm/proxy/management_endpoints/test_model_management_endpoints.py

@@ -3030,6 +3030,49 @@ class TestUpdateDBModelClearPricing:
         # team_id must survive
         assert info.get("team_id") == "team-keep-me"
 
+    def test_null_extra_param_removes_it_from_litellm_params(self):
+        """The UI's LiteLLM Params JSON editor sends explicit nulls for keys the
+        user deleted. Those keys must be removed from the stored params instead
+        of being resurrected by the merge (regression: deleted reasoning_effort
+        reappeared after a page refresh)."""
+        from litellm.proxy.management_endpoints.model_management_endpoints import (
+            update_db_model,
+        )
+        from litellm.types.router import Deployment, LiteLLM_Params, ModelInfo, updateLiteLLMParams
+
+        db_model = Deployment(
+            model_name="gpt-4o",
+            litellm_params=LiteLLM_Params(model="openai/gpt-4o", reasoning_effort="high"),
+            model_info=ModelInfo(id="dep-extra-0"),
+        )
+
+        result = update_db_model(
+            db_model=db_model,
+            updated_patch=updateDeployment(
+                litellm_params=updateLiteLLMParams(**{"reasoning_effort": None})
+            ),
+        )
+
+        params = json.loads(result["litellm_params"])
+        assert "reasoning_effort" not in params
+        assert params["model"] == "openai/gpt-4o"
+
+    def test_null_model_is_never_cleared(self):
+        """A deployment without a model is invalid, so an explicit-null model
+        must not remove the stored one."""
+        from litellm.proxy.management_endpoints.model_management_endpoints import (
+            update_db_model,
+        )
+        from litellm.types.router import updateLiteLLMParams
+
+        result = update_db_model(
+            db_model=_build_db_model_with_pricing(),
+            updated_patch=updateDeployment(litellm_params=updateLiteLLMParams(model=None)),
+        )
+
+        params = json.loads(result["litellm_params"])
+        assert params["model"] == "openai/*"
+
     def test_clear_survives_model_info_passthrough_with_old_pricing(self):
         """Realistic UI submit shape: the patch carries BOTH blobs. The
         model_info portion still has the old pricing because the form

ui/litellm-dashboard/src/components/ModelInfoEditForm.tsx

@@ -205,6 +205,15 @@ const perMillionTokens = (...rates: (number | null | undefined)[]): number | nul
   return rate == null ? null : rate * 1_000_000;
 };
 
+export const editableExtraParams = (
+  litellmParams: Record<string, unknown> | null | undefined,
+): Record<string, unknown> =>
+  Object.fromEntries(
+    Object.entries(litellmParams || {}).filter(
+      ([key, value]) => key !== "litellm_credential_name" && !isMaskedSecret(value),
+    ),
+  );
+
 export const toModelEditFormValues = (localModelData: any, isWildcardModel: boolean): ModelEditFormValues => ({
   model_name: localModelData.model_name,
   litellm_model_name: localModelData.litellm_model_name,
@@ -251,15 +260,7 @@ export const toModelEditFormValues = (localModelData: any, isWildcardModel: bool
   // antd never mounted this field for a non-wildcard model, so the key must be absent, not null.
   ...(isWildcardModel ? { health_check_model: localModelData.model_info?.health_check_model } : {}),
   litellm_credential_name: localModelData.litellm_params?.litellm_credential_name || "",
-  litellm_extra_params: JSON.stringify(
-    Object.fromEntries(
-      Object.entries(localModelData.litellm_params || {}).filter(
-        ([key, value]) => key !== "litellm_credential_name" && !isMaskedSecret(value),
-      ),
-    ),
-    null,
-    2,
-  ),
+  litellm_extra_params: JSON.stringify(editableExtraParams(localModelData.litellm_params), null, 2),
 });
 
 const displayCost = (localModelData: any, field: TouchedPricingField): string => {

ui/litellm-dashboard/src/components/model_info_view.test.tsx

@@ -1571,6 +1571,34 @@ describe("ModelInfoView", () => {
       expect(payload.litellm_params.drop_params).toBe(true);
     });
 
+    it("sends an explicit null for a key deleted from the LiteLLM extra params", async () => {
+      const withExtraParam = {
+        ...defaultModelData,
+        litellm_params: { ...defaultModelData.litellm_params, reasoning_effort: "high" },
+      };
+      mockUseModelsInfo.mockReturnValue({ data: { data: [withExtraParam] }, isLoading: false, error: null });
+      mockModelInfoV1Call.mockResolvedValue({ data: [withExtraParam] });
+      const user = userEvent.setup();
+      await enterEditMode(user);
+
+      const extraParams = screen
+        .getAllByRole("textbox")
+        .find(
+          (input) =>
+            input.tagName === "TEXTAREA" && (input as HTMLTextAreaElement).value.includes('"reasoning_effort"'),
+        ) as HTMLTextAreaElement;
+      const withoutReasoningEffort = JSON.parse(extraParams.value);
+      delete withoutReasoningEffort.reasoning_effort;
+      await user.clear(extraParams);
+      await user.paste(JSON.stringify(withoutReasoningEffort));
+
+      const payload = await save(user);
+
+      expect(payload.litellm_params.reasoning_effort).toBeNull();
+      expect(payload.litellm_params.model).toBe("gpt-4");
+      expect(payload.litellm_params.api_base).toBe("https://api.openai.com/v1");
+    });
+
     it("sends the credential picked in the selector", async () => {
       mockCredentialListCall.mockResolvedValue({
         credentials: [

ui/litellm-dashboard/src/components/model_info_view.tsx

@@ -42,7 +42,11 @@ import {
 } from "./networking";
 import { Logo } from "@/components/molecules/logo/Logo";
 import UpdateModelCredentialsModal from "./update_model_credentials_modal";
-import ModelInfoEditForm, { type ModelEditFormValues, type TouchedPricingField } from "./ModelInfoEditForm";
+import ModelInfoEditForm, {
+  editableExtraParams,
+  type ModelEditFormValues,
+  type TouchedPricingField,
+} from "./ModelInfoEditForm";
 import { Tag } from "./tag_management/types";
 import { getDisplayModelName } from "./view_model/model_name_display";
 import { Dialog, DialogContent, DialogFooter, DialogHeader, DialogTitle } from "@/components/ui/dialog";
@@ -426,6 +430,15 @@ export default function ModelInfoView({
         return;
       }
 
+      // Keys the user deleted from the LiteLLM Params JSON editor must be sent as
+      // explicit nulls: the backend PATCH merges params, so an absent key would
+      // silently keep its old value.
+      for (const key of Object.keys(editableExtraParams(localModelData?.litellm_params))) {
+        if (!(key in parsedExtraParams) && updatedLitellmParams[key] === undefined) {
+          updatedLitellmParams[key] = null;
+        }
+      }
+
       // Final guard: never PATCH a redacted secret. The /model/info snapshot that
       // seeds this form masks secrets, and any save re-sends the whole params blob;
       // without this strip a masked value would be re-encrypted over the real secret.
@@ -440,11 +453,12 @@ export default function ModelInfoView({
 
       await modelPatchUpdateCall(accessToken, updateData, modelId);
 
+      // The backend removes explicitly-null keys, so mirror that removal locally.
       const updatedModelData = {
         ...localModelData,
         model_name: values.model_name,
         litellm_model_name: values.litellm_model_name,
-        litellm_params: safeLitellmParams,
+        litellm_params: Object.fromEntries(Object.entries(safeLitellmParams).filter(([, value]) => value !== null)),
         model_info: updatedModelInfo,
       };