From 969cde4f0ce224260ab8e07e2f2cb33a75f25e7a Mon Sep 17 00:00:00 2001
From: Moe Khalil <moe@berri.ai>
Date: Fri, 18 Sep 2026 20:07:07 +0000
Subject: [PATCH] feat(ui): complete JEV auto router configuration and
 connection probes

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
---
 .../AutoRouters/autoRouterRows.test.ts        |   9 +-
 .../components/AutoRouters/autoRouterRows.ts  |   1 +
 .../add_model/ClassificationMethodConfig.tsx  |  14 ++
 .../add_model/ComplexityRouterConfig.tsx      |  35 ++--
 .../JevClassifierConfig.integration.test.tsx  | 158 ++++++++++++++++++
 .../add_model/JevClassifierConfig.tsx         |  88 ++++++++++
 .../JevConnectionTest.integration.test.tsx    | 148 ++++++++++++++++
 .../add_model/NonReasoningTierToggle.tsx      |   2 +-
 .../components/add_model/TierConfigIntro.tsx  |   3 +
 .../add_model/add_auto_router_tab.tsx         |  63 ++++---
 .../add_model/auto_router_connection_test.tsx |  72 +++++++-
 ...d_auto_router_routing_test_request.test.ts |  37 +++-
 .../build_auto_router_routing_test_request.ts |  33 ++++
 .../build_complexity_router_config.test.ts    |  94 +++++++++++
 .../build_complexity_router_config.ts         |  83 +++++----
 .../classifier_type_transition.test.ts        |  41 ++++-
 .../add_model/classifier_type_transition.ts   |  17 +-
 .../components/add_model/classifier_types.ts  |  15 ++
 .../add_model/jev_classifier_config.ts        |  28 ++++
 .../add_model/nonReasoningTierFields.ts       |   2 +-
 .../src/components/add_model/tier_rows.ts     |   2 +-
 ...d_updated_complexity_router_config.test.ts |  65 ++++++-
 .../edit_auto_router_modal.tsx                |  10 +-
 .../src/components/model_info_view.tsx        |   7 +
 .../src/components/networking.tsx             |   2 +-
 .../RoutingDecisionCard.test.tsx              |   4 +-
 .../LogDetailsDrawer/RoutingDecisionCard.tsx  |  23 ++-
 .../src/lib/autorouter_presets.test.ts        |  26 +++
 .../src/lib/autorouter_presets.ts             |   9 +-
 29 files changed, 978 insertions(+), 113 deletions(-)
 create mode 100644 ui/litellm-dashboard/src/components/add_model/JevClassifierConfig.integration.test.tsx
 create mode 100644 ui/litellm-dashboard/src/components/add_model/JevClassifierConfig.tsx
 create mode 100644 ui/litellm-dashboard/src/components/add_model/JevConnectionTest.integration.test.tsx
 create mode 100644 ui/litellm-dashboard/src/components/add_model/classifier_types.ts
 create mode 100644 ui/litellm-dashboard/src/components/add_model/jev_classifier_config.ts

diff --git a/ui/litellm-dashboard/src/app/(dashboard)/models-and-endpoints/components/AutoRouters/autoRouterRows.test.ts b/ui/litellm-dashboard/src/app/(dashboard)/models-and-endpoints/components/AutoRouters/autoRouterRows.test.ts
index 23585f6c110..79c4243271e 100644
--- a/ui/litellm-dashboard/src/app/(dashboard)/models-and-endpoints/components/AutoRouters/autoRouterRows.test.ts
+++ b/ui/litellm-dashboard/src/app/(dashboard)/models-and-endpoints/components/AutoRouters/autoRouterRows.test.ts
@@ -83,13 +83,16 @@ describe("autoRouterRows", () => {
     expect(row.targets).toEqual(["gpt-4o-mini", "anthropic-sonnet-4-6"]);
   });
 
-  it("labels a router using the LLM classifier", () => {
+  it.each([
+    ["llm", "LLM Classifier"],
+    ["jev", "JEV Classifier"],
+  ])("labels a router using the %s classifier", (classifierType, label) => {
     const row = toAutoRouterRow(
       {
         ...complexityDeployment,
         litellm_params: {
           ...complexityDeployment.litellm_params,
-          complexity_router_config: { tiers: {}, classifier_type: "llm", adaptive: true },
+          complexity_router_config: { tiers: {}, classifier_type: classifierType, adaptive: true },
         },
       },
       0,
@@ -97,7 +100,7 @@ describe("autoRouterRows", () => {
       null,
     );
 
-    expect(row.typeLabel).toBe("LLM Classifier");
+    expect(row.typeLabel).toBe(label);
   });
 
   it("treats a deployment carrying complexity_router_config as complexity even off the canonical model string", () => {
diff --git a/ui/litellm-dashboard/src/app/(dashboard)/models-and-endpoints/components/AutoRouters/autoRouterRows.ts b/ui/litellm-dashboard/src/app/(dashboard)/models-and-endpoints/components/AutoRouters/autoRouterRows.ts
index dffb5811c0d..1faf3408c23 100644
--- a/ui/litellm-dashboard/src/app/(dashboard)/models-and-endpoints/components/AutoRouters/autoRouterRows.ts
+++ b/ui/litellm-dashboard/src/app/(dashboard)/models-and-endpoints/components/AutoRouters/autoRouterRows.ts
@@ -57,6 +57,7 @@ const dedupe = (models: string[]): string[] => Array.from(new Set(models));
 
 const COMPLEXITY_TYPE_LABELS: Record<string, string> = {
   llm: "LLM Classifier",
+  jev: "JEV Classifier",
   capability: "Capability",
   llm_v2: "Fuse v2",
   heuristic_first: "Heuristic first",
diff --git a/ui/litellm-dashboard/src/components/add_model/ClassificationMethodConfig.tsx b/ui/litellm-dashboard/src/components/add_model/ClassificationMethodConfig.tsx
index 64b08fc9ed1..322515e0ac5 100644
--- a/ui/litellm-dashboard/src/components/add_model/ClassificationMethodConfig.tsx
+++ b/ui/litellm-dashboard/src/components/add_model/ClassificationMethodConfig.tsx
@@ -1,4 +1,5 @@
 import { transitionClassifierType } from "./classifier_type_transition";
+import JevClassifierConfig from "./JevClassifierConfig";
 import { Info } from "lucide-react";
 import { SimpleTooltip } from "@/components/ui/tooltip";
 import { MultiSelect } from "@/components/shared/MultiSelect";
@@ -37,6 +38,7 @@ import {
   effectiveTierLabel,
   heuristicScoringRole,
   usesLlmClassifier,
+  usesClassifierContext,
   DEFAULT_HYBRID_BOUNDARY_MARGIN,
   HEURISTIC_FIRST_MAX_TIER_KEYS,
   effectiveClassifierType,
@@ -208,6 +210,13 @@ const ClassifierTypeRadios: React.FC<{
             <span className="text-muted-foreground">calls a model to decide the tier (e.g. a small/fast model)</span>
           </span>
         </Label>
+        <Label className="items-start font-normal leading-normal">
+          <RadioGroupItem value="jev" className="mt-0.5" />
+          <span>
+            <strong className="font-semibold">JEV Classifier</strong>{" "}
+            <span className="text-muted-foreground">uses TypeSafe System One Choice to decide the tier</span>
+          </span>
+        </Label>
         <SimpleTooltip content={scorerLockedReason}>
           <Label className="items-start font-normal leading-normal has-data-disabled:cursor-not-allowed has-data-disabled:opacity-50">
             <RadioGroupItem value="heuristic_first" className="mt-0.5" disabled={scorerLocked} />
@@ -499,6 +508,7 @@ const ClassificationMethodConfig: React.FC<ClassificationMethodConfigProps> = ({
         </p>
       </div>
 
+      {classifierType === "jev" && <JevClassifierConfig value={value} onChange={onChange} />}
       {usesLlmClassifier(classifierType) && (
         <div className="mt-4 space-y-3">
           <div>
@@ -591,6 +601,10 @@ const ClassificationMethodConfig: React.FC<ClassificationMethodConfigProps> = ({
               />
             )}
           </div>
+        </div>
+      )}
+      {usesClassifierContext(classifierType) && (
+        <div className="mt-4 space-y-3">
           <RestrictedSection heading="If the classifier fails" by={restrictedBy(value, "classifierFallback")}>
             <RadioGroup
               value={value.classifier_fallback ?? DEFAULT_CLASSIFIER_FALLBACK}
diff --git a/ui/litellm-dashboard/src/components/add_model/ComplexityRouterConfig.tsx b/ui/litellm-dashboard/src/components/add_model/ComplexityRouterConfig.tsx
index f6b50ce20bc..b86820787c5 100644
--- a/ui/litellm-dashboard/src/components/add_model/ComplexityRouterConfig.tsx
+++ b/ui/litellm-dashboard/src/components/add_model/ComplexityRouterConfig.tsx
@@ -1,4 +1,7 @@
 import RoutingOptions from "./RoutingOptions";
+import type { JevClassifierConfig } from "./jev_classifier_config";
+import { type ClassifierType } from "./classifier_types";
+export { type ClassifierType, usesLlmClassifier, usesClassifierContext } from "./classifier_types";
 import PlanModeOverrideControls from "./PlanModeOverrideControls";
 import ForecastClassifierConfig, { ForecastSolverModels } from "./ForecastClassifierConfig";
 import { isForecastClassifier, type CapabilitySettings, type FuseSettings } from "./forecast_classifier_config";
@@ -147,23 +150,6 @@ export interface ClassifierLLMConfig {
   system_prompt?: string;
 }
 
-export type ClassifierType =
-  | "heuristic"
-  | "heuristic_v2"
-  | "llm"
-  | "heuristic_first"
-  | "hybrid"
-  | "capability"
-  | "llm_v2";
-
-/**
- * Whether this router can call classifier_llm_config.model. Mirrors the backend's
- * ComplexityRouterConfig.uses_llm_classifier, and is the single gate for every classifier-only
- * control and payload key, so a new chaining type cannot strip knobs the operator set.
- */
-export const usesLlmClassifier = (classifierType: ClassifierType): boolean =>
-  (["llm", "heuristic_first", "hybrid", "capability", "llm_v2"] as const).some((type) => type === classifierType);
-
 export type ClassifierFallback = "heuristic" | "default_model";
 
 export const DEFAULT_CLASSIFIER_FALLBACK: ClassifierFallback = "heuristic";
@@ -200,7 +186,7 @@ export const heuristicScoringRole = (value: ComplexityRouterConfigValue): Heuris
 // Derived, never written into the value, so undoing a tier edit reverts the form with nothing left behind.
 export const effectiveClassifierType = (
   value: Pick<ComplexityRouterConfigValue, "custom_tier_set" | "classifier_type">,
-): ClassifierType => (value.custom_tier_set ? "llm" : value.classifier_type);
+): ClassifierType => (value.custom_tier_set && value.classifier_type !== "jev" ? "llm" : value.classifier_type);
 
 const rowOrigin = (row: TierRow, editing: boolean): string => {
   if (!editing) return row.id;
@@ -251,8 +237,8 @@ const TierSetToolbar: React.FC<{
     </div>
     {editing && (
       <span className="block mt-1 text-xs text-muted-foreground">
-        Add or remove tiers to define your own set. Every custom tier needs a definition the LLM classifier routes on,
-        and an edited set requires the LLM classification method
+        Add or remove tiers to define your own set. Every custom tier needs a definition the classifier routes on, and
+        an edited set requires the LLM or JEV classification method
       </span>
     )}
     {editing && keywordRulesError && (
@@ -271,7 +257,7 @@ const FallbackTierField: React.FC<{
   <div className="mt-4">
     <div className="flex items-center gap-2 mb-2">
       <strong className="text-base font-semibold">Fallback Tier</strong>
-      <SimpleTooltip content="Where requests route when the LLM classifier errors, times out, or returns an unparseable reply. Required for an edited tier set: the heuristic scorer cannot produce your tiers.">
+      <SimpleTooltip content="Where requests route when the classifier errors, times out, or returns an unparseable reply. Required for an edited tier set: the heuristic scorer cannot produce your tiers">
         <Info className="size-4 text-muted-foreground" />
       </SimpleTooltip>
     </div>
@@ -377,6 +363,7 @@ export interface ComplexityRouterConfigValue {
   capability_classifier_config?: CapabilitySettings;
   llm_v2_config?: FuseSettings;
   classifier_llm_config?: ClassifierLLMConfig;
+  jev_classifier_config?: JevClassifierConfig;
   classifier_context_window_size?: number;
   classifier_context_budget_chars?: number;
   classifier_context_per_turn_chars?: number;
@@ -641,7 +628,11 @@ const ComplexityRouterConfig: React.FC<ComplexityRouterConfigProps> = ({
           <Card>
             <CardContent>
               {!customTierSet && (
-                <NonReasoningTierToggle value={value} onChange={onChange} available={value.classifier_type === "llm"} />
+                <NonReasoningTierToggle
+                  value={value}
+                  onChange={onChange}
+                  available={value.classifier_type === "llm" || value.classifier_type === "jev"}
+                />
               )}
 
               {tierRows.map((row, index) => {
diff --git a/ui/litellm-dashboard/src/components/add_model/JevClassifierConfig.integration.test.tsx b/ui/litellm-dashboard/src/components/add_model/JevClassifierConfig.integration.test.tsx
new file mode 100644
index 00000000000..aae32f09959
--- /dev/null
+++ b/ui/litellm-dashboard/src/components/add_model/JevClassifierConfig.integration.test.tsx
@@ -0,0 +1,158 @@
+import React, { useState } from "react";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { fireEvent, renderWithProviders, screen } from "../../../tests/test-utils";
+import useAuthorized from "@/app/(dashboard)/hooks/useAuthorized";
+import ClassificationMethodConfig from "./ClassificationMethodConfig";
+import AutoRouterClassifierTabs from "./AutoRouterClassifierTabs";
+import JevEditor from "./JevClassifierConfig";
+import { type ComplexityRouterConfigValue } from "./ComplexityRouterConfig";
+import {
+  buildUpdatedComplexityRouterConfig,
+  hydrateComplexityRouterConfig,
+} from "../edit_auto_router/edit_auto_router_modal";
+import { applyTierSetAction } from "./tier_set_actions";
+import { testAutoRouterRouting } from "../networking";
+import { buildSavedJevConnectionTestRequest } from "./build_auto_router_routing_test_request";
+
+vi.mock("@/app/(dashboard)/hooks/useAuthorized", () => ({
+  default: vi.fn(() => ({
+    isLoading: false,
+    isAuthorized: true,
+    token: "token",
+    accessToken: "token",
+    userId: "user",
+    userEmail: "user@example.com",
+    userRole: "Admin",
+    userRoleLabel: "Admin",
+    isViewOnly: false,
+    premiumUser: false,
+    disabledPersonalKeyCreation: false,
+    showSSOBanner: false,
+  })),
+}));
+
+vi.mock("@/components/networking", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("@/components/networking")>()),
+  getComplexityScorerDefaults: vi.fn(async () => ({
+    tier_boundaries: {},
+    token_thresholds: {},
+    dimension_weights: {},
+  })),
+  testAutoRouterRouting: vi.fn(async () => ({ status: "error", error: "fixture" })),
+}));
+
+const initial: ComplexityRouterConfigValue = {
+  classifier_type: "llm",
+  classifier_llm_config: { model: "judge", timeout_ms: 1000 },
+  tiers: { SIMPLE: ["fast"], MEDIUM: ["mid"], COMPLEX: ["strong"], REASONING: ["reasoner"] },
+};
+
+function Form() {
+  const [value, setValue] = useState(initial);
+  return (
+    <AutoRouterClassifierTabs value={value} onChange={setValue}>
+      <ClassificationMethodConfig
+        value={value}
+        onChange={setValue}
+        modelOptions={[{ value: "judge", label: "judge" }]}
+        effortOptionsByModel={{ judge: ["low"] }}
+        customTechnicalKeywords={[]}
+        onCustomTechnicalKeywordsChange={() => {}}
+      />
+      <button
+        onClick={() =>
+          setValue(
+            applyTierSetAction(value, [], {
+              kind: "patch",
+              id: "SIMPLE",
+              patch: { name: "QUICK", definition: "Quick tasks" },
+            }).value,
+          )
+        }
+      >
+        Customize tiers
+      </button>
+      <button
+        onClick={() =>
+          setValue(hydrateComplexityRouterConfig(buildUpdatedComplexityRouterConfig({}, value), undefined))
+        }
+      >
+        Save and reload
+      </button>
+      <button
+        onClick={() => {
+          const request = buildSavedJevConnectionTestRequest(buildUpdatedComplexityRouterConfig({}, value));
+          if (request) void testAutoRouterRouting("token", request);
+        }}
+      >
+        Probe current config
+      </button>
+    </AutoRouterClassifierTabs>
+  );
+}
+
+describe("JEV classifier editor", () => {
+  afterEach(() => vi.mocked(useAuthorized).mockReset());
+  it("uses built-in JEV without a license and preserves custom tiers and context through reload", () => {
+    renderWithProviders(<Form />);
+    expect(screen.getByLabelText("Classifier Model")).toBeInTheDocument();
+    expect(screen.getByText("Reasoning Effort")).toBeInTheDocument();
+    expect(screen.getByText("Classifier Prompt")).toBeInTheDocument();
+    expect(screen.getByRole("switch", { name: "Use images for classification" })).toBeInTheDocument();
+    fireEvent.click(screen.getByRole("radio", { name: /JEV Classifier/ }));
+    expect(screen.getByRole("tab", { name: "Complexity" })).toHaveAttribute("aria-selected", "true");
+    expect(screen.getByLabelText("JEV Model")).toHaveValue("jev-latest");
+    expect(screen.getByLabelText("JEV Instructions")).toBeDisabled();
+    expect(screen.queryByLabelText("Classifier Model")).not.toBeInTheDocument();
+    expect(screen.queryByText("Reasoning Effort")).not.toBeInTheDocument();
+    expect(screen.queryByText("Classifier Prompt")).not.toBeInTheDocument();
+    expect(screen.queryByRole("switch", { name: "Use images for classification" })).not.toBeInTheDocument();
+    fireEvent.change(screen.getByLabelText("JEV Model"), { target: { value: "jev-test" } });
+    fireEvent.change(screen.getByLabelText("JEV Timeout (ms)"), { target: { value: "4200" } });
+    fireEvent.change(screen.getByLabelText("Context Window Size"), { target: { value: "6" } });
+    fireEvent.change(screen.getByLabelText("Circuit breaker cooldown (seconds)"), { target: { value: "50" } });
+    fireEvent.click(screen.getByRole("switch", { name: "Classifier circuit breaker" }));
+    fireEvent.click(screen.getByRole("button", { name: "Customize tiers" }));
+    fireEvent.click(screen.getByRole("button", { name: "Save and reload" }));
+    expect(screen.getByRole("radio", { name: /JEV Classifier/ })).toBeChecked();
+    expect(screen.getByLabelText("JEV Model")).toHaveValue("jev-test");
+    expect(screen.getByLabelText("JEV Timeout (ms)")).toHaveValue(4200);
+    expect(screen.getByLabelText("Context Window Size")).toHaveValue("6");
+    expect(screen.getByRole("switch", { name: "Classifier circuit breaker" })).not.toBeChecked();
+    fireEvent.click(screen.getByRole("button", { name: "Probe current config" }));
+    expect(testAutoRouterRouting).toHaveBeenCalledWith(
+      "token",
+      expect.objectContaining({
+        complexity_router_config: expect.objectContaining({
+          classifier_type: "jev",
+          jev_classifier_config: {
+            model: "jev-test",
+            timeout_ms: 4200,
+            circuit_breaker_enabled: false,
+            circuit_breaker_cooldown_seconds: 50,
+          },
+          tiers: expect.objectContaining({ QUICK: ["fast"] }),
+        }),
+      }),
+    );
+  });
+
+  it("allows licensed instructions and can restore built-in instructions", () => {
+    const authorized = useAuthorized();
+    vi.mocked(useAuthorized).mockReturnValue({ ...authorized, premiumUser: true });
+    const LicensedForm = () => {
+      const [value, setValue] = useState<ComplexityRouterConfigValue>({
+        ...initial,
+        classifier_type: "jev",
+        jev_classifier_config: { model: "jev-latest", timeout_ms: 3000, instructions: "Existing instructions" },
+      });
+      return <JevEditor value={value} onChange={setValue} />;
+    };
+    renderWithProviders(<LicensedForm />);
+    expect(screen.getByLabelText("JEV Instructions")).toBeEnabled();
+    fireEvent.change(screen.getByLabelText("JEV Instructions"), { target: { value: "New instructions" } });
+    expect(screen.getByLabelText("JEV Instructions")).toHaveValue("New instructions");
+    fireEvent.click(screen.getByRole("button", { name: "Restore built-in JEV instructions" }));
+    expect(screen.getByLabelText("JEV Instructions")).toHaveValue("");
+  });
+});
diff --git a/ui/litellm-dashboard/src/components/add_model/JevClassifierConfig.tsx b/ui/litellm-dashboard/src/components/add_model/JevClassifierConfig.tsx
new file mode 100644
index 00000000000..25286eaef07
--- /dev/null
+++ b/ui/litellm-dashboard/src/components/add_model/JevClassifierConfig.tsx
@@ -0,0 +1,88 @@
+import React, { useId } from "react";
+import useAuthorized from "@/app/(dashboard)/hooks/useAuthorized";
+import { Button } from "@/components/ui/button";
+import { Input } from "@/components/ui/input";
+import { Label } from "@/components/ui/label";
+import { Textarea } from "@/components/ui/textarea";
+import { SimpleTooltip } from "@/components/ui/tooltip";
+import ClassifierCircuitBreakerConfig from "./ClassifierCircuitBreakerConfig";
+import type { ComplexityRouterConfigValue } from "./ComplexityRouterConfig";
+import { defaultJevClassifierConfig } from "./jev_classifier_config";
+
+export default function JevClassifierConfig({
+  value,
+  onChange,
+}: {
+  value: ComplexityRouterConfigValue;
+  onChange: (value: ComplexityRouterConfigValue) => void;
+}) {
+  const id = useId();
+  const { premiumUser } = useAuthorized();
+  const config = value.jev_classifier_config ?? defaultJevClassifierConfig();
+  const update = (patch: Partial<typeof config>) =>
+    onChange({ ...value, jev_classifier_config: { ...config, ...patch } });
+
+  return (
+    <div className="mt-4 space-y-3">
+      <p className="text-sm text-muted-foreground">
+        Uses TypeSafe System One Choice evaluation with your configured tiers
+      </p>
+      <div>
+        <Label htmlFor={`${id}-model`}>JEV Model</Label>
+        <Input id={`${id}-model`} value={config.model} onChange={(event) => update({ model: event.target.value })} />
+      </div>
+      <div>
+        <Label htmlFor={`${id}-timeout`}>JEV Timeout (ms)</Label>
+        <Input
+          id={`${id}-timeout`}
+          type="number"
+          min={1}
+          step={1}
+          value={config.timeout_ms}
+          onChange={(event) => update({ timeout_ms: Number(event.target.value) })}
+        />
+      </div>
+      <ClassifierCircuitBreakerConfig
+        value={config}
+        onChange={(next) =>
+          update({
+            circuit_breaker_enabled: next.circuit_breaker_enabled,
+            circuit_breaker_cooldown_seconds: next.circuit_breaker_cooldown_seconds,
+          })
+        }
+      />
+      <div>
+        <Label htmlFor={`${id}-instructions`}>JEV Instructions</Label>
+        <SimpleTooltip
+          content={!premiumUser ? "Custom JEV instructions require a LiteLLM Enterprise license" : undefined}
+        >
+          <div>
+            <Textarea
+              id={`${id}-instructions`}
+              value={config.instructions ?? ""}
+              disabled={!premiumUser}
+              placeholder="Leave blank to use the built-in instructions"
+              onChange={(event) => update({ instructions: event.target.value || undefined })}
+            />
+          </div>
+        </SimpleTooltip>
+        {config.instructions && (
+          <Button variant="outline" type="button" onClick={() => update({ instructions: undefined })}>
+            Restore built-in JEV instructions
+          </Button>
+        )}
+        <p className="text-xs text-muted-foreground">
+          Built-in JEV is available without a license and uses the shipped tier criteria
+          {!premiumUser && (
+            <>
+              . Custom instructions require LiteLLM Enterprise. Get a trial key{" "}
+              <a href="https://www.litellm.ai/#pricing" target="_blank" rel="noopener noreferrer" className="underline">
+                here
+              </a>
+            </>
+          )}
+        </p>
+      </div>
+    </div>
+  );
+}
diff --git a/ui/litellm-dashboard/src/components/add_model/JevConnectionTest.integration.test.tsx b/ui/litellm-dashboard/src/components/add_model/JevConnectionTest.integration.test.tsx
new file mode 100644
index 00000000000..8f0ad88eb65
--- /dev/null
+++ b/ui/litellm-dashboard/src/components/add_model/JevConnectionTest.integration.test.tsx
@@ -0,0 +1,148 @@
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { fireEvent, renderWithProviders, screen, waitFor } from "../../../tests/test-utils";
+import AutoRouterConnectionTest from "./auto_router_connection_test";
+import AutoRouterRoutingTest from "./AutoRouterRoutingTest";
+import { buildAutoRouterTestTargets } from "./build_auto_router_test_targets";
+import {
+  buildSavedJevConnectionTestRequest,
+  JEV_CONNECTION_TEST_PROMPT,
+} from "./build_auto_router_routing_test_request";
+import { buildComplexityRouterConfig } from "./build_complexity_router_config";
+
+vi.mock(
+  "@/app/(dashboard)/hooks/autoRouter/useComplexityScorerDefaults",
+  async () => await import("../../../tests/mocks/complexityScorerDefaults"),
+);
+
+const config = buildComplexityRouterConfig({
+  classifierType: "jev",
+  jevClassifierConfig: { model: "jev-latest", timeout_ms: 3000 },
+  tiers: { SIMPLE: ["fast"], MEDIUM: ["mid"], COMPLEX: ["strong"], REASONING: ["reasoner"] },
+  defaultModel: undefined,
+  planModeMinTier: undefined,
+  tierLabels: undefined,
+  classifierLlmConfig: undefined,
+  classifierContextWindowSize: undefined,
+  classifierContextBudgetChars: undefined,
+  classifierContextIncludeAssistantTurns: undefined,
+  classifierFallback: undefined,
+  classificationPrompt: undefined,
+  classificationExamples: undefined,
+  heuristicFirstMaxTier: undefined,
+  classificationMode: undefined,
+  sessionAffinity: false,
+  deploymentAffinity: true,
+  customTechnicalKeywords: [],
+  keywordTierRules: [],
+  semanticMatchingEnabled: false,
+  embeddingModel: undefined,
+  matchThreshold: 0.5,
+  escalationKeywords: [],
+  adaptive: false,
+  adaptiveWeights: { quality: 0.3, cost: 0.7 },
+  tierDistancePenalty: 0.5,
+  adaptiveEligible: "all",
+  returnRawModelName: false,
+});
+const request = buildSavedJevConnectionTestRequest(JSON.stringify(config), "fast", "my-router");
+const targets = buildAutoRouterTestTargets({
+  tiers: Object.entries(config.tiers),
+  semanticMatchingEnabled: false,
+  embeddingModel: undefined,
+});
+const response = (cause: string) => ({
+  routed_model: "fast",
+  routed_model_configured: true,
+  routing_decision: {
+    cause,
+    tier: "SIMPLE",
+    classifier_model: "jev-latest",
+    classifier_confidence: 0.8,
+    classifier_probabilities: { SIMPLE: 0.8, REASONING: 0.2 },
+    classifier_cost: 0.00001234,
+  },
+});
+
+afterEach(() => vi.unstubAllGlobals());
+
+describe("JEV network probes", () => {
+  it.each(["jev_classifier", "classifier_fallback", "default_model_fallback", "keyword_match"])(
+    "probes the routing endpoint independently of tier models and checks the cause %s",
+    async (cause) => {
+      const fetchMock = vi.fn<typeof fetch>(
+        async (input) =>
+          new Response(JSON.stringify(String(input).endsWith("/auto_router/test_routing") ? response(cause) : {})),
+      );
+      vi.stubGlobal("fetch", fetchMock);
+      const onTestComplete = vi.fn();
+      renderWithProviders(
+        <AutoRouterConnectionTest
+          accessToken="test-token"
+          targets={targets}
+          jevRequest={request}
+          onTestComplete={onTestComplete}
+        />,
+      );
+      await waitFor(() => expect(onTestComplete).toHaveBeenCalledOnce());
+      expect(fetchMock).toHaveBeenCalledWith(
+        expect.stringContaining("/auto_router/test_routing"),
+        expect.objectContaining({
+          method: "POST",
+          body: expect.any(String),
+        }),
+      );
+      const routingCall = fetchMock.mock.calls.find(([url]) => String(url).endsWith("/auto_router/test_routing"));
+      expect(JSON.parse(String(routingCall?.[1]?.body))).toEqual({
+        prompt: JEV_CONNECTION_TEST_PROMPT,
+        complexity_router_config: config,
+        default_model: "fast",
+        router_name: "my-router",
+      });
+      expect(fetchMock).toHaveBeenCalledTimes(5);
+      expect(screen.getAllByTestId("test-status-success")).toHaveLength(4);
+      expect(screen.getByRole("status", { name: "JEV connection" })).toHaveTextContent(
+        cause === "jev_classifier"
+          ? "JEV classification succeeded"
+          : `JEV was not reached successfully (routing cause: ${cause})`,
+      );
+    },
+  );
+
+  it("shows routing diagnostics from the real networking response", async () => {
+    vi.stubGlobal(
+      "fetch",
+      vi.fn<typeof fetch>(async () => new Response(JSON.stringify(response("jev_classifier")))),
+    );
+    renderWithProviders(
+      <AutoRouterRoutingTest
+        accessToken="token"
+        config={config}
+        defaultModel="fast"
+        routerName="router"
+        teamId={undefined}
+      />,
+    );
+    fireEvent.change(screen.getByTestId("auto-router-routing-test-prompt"), { target: { value: "Hello" } });
+    fireEvent.click(screen.getByTestId("auto-router-routing-test-send"));
+    expect(await screen.findByText("JEV classifier")).toBeInTheDocument();
+    expect(screen.getByText("jev-latest")).toBeInTheDocument();
+    expect(screen.getByText("80.0%")).toBeInTheDocument();
+    expect(screen.getByText("SIMPLE: 80.0%")).toBeInTheDocument();
+    expect(screen.getByText("REASONING: 20.0%")).toBeInTheDocument();
+    expect(screen.getByText("$0.00001234")).toBeInTheDocument();
+  });
+
+  it("reports a classifier endpoint error while still checking downstream models", async () => {
+    vi.stubGlobal(
+      "fetch",
+      vi.fn<typeof fetch>(async (input) =>
+        String(input).endsWith("/auto_router/test_routing")
+          ? new Response(JSON.stringify({ detail: "JEV classifier unavailable" }), { status: 503 })
+          : new Response("{}"),
+      ),
+    );
+    renderWithProviders(<AutoRouterConnectionTest accessToken="token" targets={targets} jevRequest={request} />);
+    expect(await screen.findByText("JEV classifier unavailable")).toBeInTheDocument();
+    expect(screen.getAllByTestId("test-status-success")).toHaveLength(4);
+  });
+});
diff --git a/ui/litellm-dashboard/src/components/add_model/NonReasoningTierToggle.tsx b/ui/litellm-dashboard/src/components/add_model/NonReasoningTierToggle.tsx
index 5ca0d5517af..c373d360ba1 100644
--- a/ui/litellm-dashboard/src/components/add_model/NonReasoningTierToggle.tsx
+++ b/ui/litellm-dashboard/src/components/add_model/NonReasoningTierToggle.tsx
@@ -39,7 +39,7 @@ const NonReasoningTierToggle: React.FC<{
       <span className="block text-xs text-muted-foreground">
         Adds NON_REASONING below Simple, for operational agent traffic that relays or reformats information rather than
         reasoning about it. Escalation still moves up out of it when a request needs more.
-        {!available && " Requires the LLM classification method."}
+        {!available && " Requires the LLM or JEV classification method"}
       </span>
       <Separator className="my-4" />
     </>
diff --git a/ui/litellm-dashboard/src/components/add_model/TierConfigIntro.tsx b/ui/litellm-dashboard/src/components/add_model/TierConfigIntro.tsx
index 4b14307dda5..7d6e0d997d1 100644
--- a/ui/litellm-dashboard/src/components/add_model/TierConfigIntro.tsx
+++ b/ui/litellm-dashboard/src/components/add_model/TierConfigIntro.tsx
@@ -4,6 +4,9 @@ import { type ComplexityRouterConfigValue, heuristicScoringRole, usesLlmClassifi
 import { restrictedBy } from "./TierRestrictions";
 
 const tierConfigIntroText = (value: ComplexityRouterConfigValue): string => {
+  if (value.classifier_type === "jev") {
+    return "JEV classifies each request with TypeSafe System One Choice evaluation and routes it to a tier. Configure which models handle each tier";
+  }
   if (value.classifier_type === "heuristic_v2") {
     return "The complexity router classifies each request with a calibrated local four-tier model (no API calls). Configure which model(s) handle each tier.";
   }
diff --git a/ui/litellm-dashboard/src/components/add_model/add_auto_router_tab.tsx b/ui/litellm-dashboard/src/components/add_model/add_auto_router_tab.tsx
index 126d9ba2311..8a4f6e4eac9 100644
--- a/ui/litellm-dashboard/src/components/add_model/add_auto_router_tab.tsx
+++ b/ui/litellm-dashboard/src/components/add_model/add_auto_router_tab.tsx
@@ -57,7 +57,11 @@ import {
 import { activeTierName, activeTierRows, getCustomTierRowsError, resolveComplexityDefaultModel } from "./tier_rows";
 import { tierRowLabel } from "./complexity_router_tiers";
 import { buildAutoRouterTestTargets, AutoRouterTestTarget } from "./build_auto_router_test_targets";
-import AutoRouterConnectionTest from "./auto_router_connection_test";
+import { AutoRouterConnectionTestDialog } from "./auto_router_connection_test";
+import {
+  buildAutoRouterRoutingTestRequest,
+  JEV_CONNECTION_TEST_PROMPT,
+} from "./build_auto_router_routing_test_request";
 import AutoRouterRoutingTest from "./AutoRouterRoutingTest";
 import { toast } from "@/lib/toast";
 import {
@@ -405,6 +409,7 @@ const AddAutoRouterTab: React.FC<AddAutoRouterTabProps> = ({
     classificationMode: complexityRouterConfig.classification_mode,
     tierLabels: complexityRouterConfig.tier_labels,
     classifierType: complexityRouterConfig.classifier_type,
+    jevClassifierConfig: complexityRouterConfig.jev_classifier_config,
     capabilityClassifierConfig: complexityRouterConfig.capability_classifier_config,
     llmV2Config: complexityRouterConfig.llm_v2_config,
     classifierLlmConfig: complexityRouterConfig.classifier_llm_config,
@@ -839,41 +844,31 @@ const AddAutoRouterTab: React.FC<AddAutoRouterTabProps> = ({
         </DialogContent>
       </Dialog>
 
-      <Dialog
+      <AutoRouterConnectionTestDialog
         open={isTestModalVisible}
-        onOpenChange={(open) => {
-          if (!open) {
-            setIsTestModalVisible(false);
-            setIsTestingConnection(false);
-          }
+        onClose={() => {
+          setIsTestModalVisible(false);
+          setIsTestingConnection(false);
         }}
-      >
-        <DialogContent className="max-h-[calc(100dvh-2rem)] overflow-y-auto sm:max-w-[700px]">
-          <DialogHeader>
-            <DialogTitle>Connection Test Results</DialogTitle>
-          </DialogHeader>
-          {isTestModalVisible && (
-            <AutoRouterConnectionTest
-              key={connectionTestId}
-              accessToken={accessToken}
-              targets={testTargets}
-              onTestComplete={() => setIsTestingConnection(false)}
-            />
-          )}
-          <DialogFooter>
-            {" "}
-            <Button
-              variant="outline"
-              onClick={() => {
-                setIsTestModalVisible(false);
-                setIsTestingConnection(false);
-              }}
-            >
-              Close
-            </Button>
-          </DialogFooter>
-        </DialogContent>
-      </Dialog>
+        testId={connectionTestId}
+        accessToken={accessToken}
+        targets={testTargets}
+        jevRequest={
+          effectiveClassifierType(complexityRouterConfig) === "jev"
+            ? buildAutoRouterRoutingTestRequest({
+                prompt: JEV_CONNECTION_TEST_PROMPT,
+                config: buildComplexityRouterConfig(complexityRouterConfigParams),
+                defaultModel: resolveComplexityDefaultModel(
+                  complexityRouterConfig,
+                  complexityRouterConfig.default_model,
+                ),
+                routerName: watchedName,
+                teamId: requiresTeamScope ? watchedTeamId ?? undefined : undefined,
+              })
+            : undefined
+        }
+        onTestComplete={() => setIsTestingConnection(false)}
+      />
     </TooltipProvider>
   );
 };
diff --git a/ui/litellm-dashboard/src/components/add_model/auto_router_connection_test.tsx b/ui/litellm-dashboard/src/components/add_model/auto_router_connection_test.tsx
index 6ff9b8c8f83..83ce3d30f0e 100644
--- a/ui/litellm-dashboard/src/components/add_model/auto_router_connection_test.tsx
+++ b/ui/litellm-dashboard/src/components/add_model/auto_router_connection_test.tsx
@@ -1,12 +1,20 @@
 import React from "react";
 import { CircleCheck, CircleX, LoaderCircle } from "lucide-react";
 
-import { testModelGroupConnection, ModelGroupConnectionResult } from "../networking";
+import {
+  testModelGroupConnection,
+  ModelGroupConnectionResult,
+  testAutoRouterRouting,
+  AutoRouterRoutingTestRequest,
+} from "../networking";
 import { AutoRouterTestTarget } from "./build_auto_router_test_targets";
+import { Dialog, DialogContent, DialogFooter, DialogHeader, DialogTitle } from "@/components/ui/dialog";
+import { Button } from "@/components/ui/button";
 
 interface AutoRouterConnectionTestProps {
   accessToken: string;
   targets: AutoRouterTestTarget[];
+  jevRequest?: AutoRouterRoutingTestRequest;
   onTestComplete?: () => void;
 }
 
@@ -20,15 +28,36 @@ const cleanErrorMessage = (error: string): string => {
 const AutoRouterConnectionTest: React.FC<AutoRouterConnectionTestProps> = ({
   accessToken,
   targets,
+  jevRequest,
   onTestComplete,
 }) => {
   const [results, setResults] = React.useState<TargetResult[]>(() => targets.map(() => ({ status: "pending" })));
+  const [jevResult, setJevResult] = React.useState<TargetResult>({ status: "pending" });
 
   React.useEffect(() => {
     let cancelled = false;
+    const probeJev = async () => {
+      if (!jevRequest) return;
+      const response = await testAutoRouterRouting(accessToken, jevRequest);
+      if (cancelled) return;
+      if (response.status === "error") {
+        setJevResult(response);
+        return;
+      }
+      const decision = response.result.routing_decision;
+      setJevResult(
+        decision.cause === "jev_classifier"
+          ? { status: "success" }
+          : {
+              status: "error",
+              error: `JEV was not reached successfully (routing cause: ${decision.cause ?? "unknown"})`,
+            },
+      );
+    };
     const run = async () => {
-      await Promise.all(
-        targets.map(async (target, index) => {
+      await Promise.all([
+        probeJev(),
+        ...targets.map(async (target, index) => {
           const result = target.requestParams
             ? await testModelGroupConnection(accessToken, target.modelGroup, target.mode, target.requestParams)
             : await testModelGroupConnection(accessToken, target.modelGroup, target.mode);
@@ -37,7 +66,7 @@ const AutoRouterConnectionTest: React.FC<AutoRouterConnectionTestProps> = ({
             result.status === "error" ? { status: "error", error: cleanErrorMessage(result.error) } : result;
           setResults((prev) => prev.map((r, i) => (i === index ? cleaned : r)));
         }),
-      );
+      ]);
       if (!cancelled && onTestComplete) onTestComplete();
     };
     run();
@@ -47,7 +76,7 @@ const AutoRouterConnectionTest: React.FC<AutoRouterConnectionTestProps> = ({
     // eslint-disable-next-line react-hooks/exhaustive-deps -- probes run once per mount; the parent remounts via `key` to start a fresh test, and re-running on prop identity changes would refire paid requests
   }, []);
 
-  if (targets.length === 0) {
+  if (targets.length === 0 && !jevRequest) {
     return (
       <p className="text-sm text-muted-foreground">
         No complexity tiers are configured yet, so there is nothing to test.
@@ -61,6 +90,16 @@ const AutoRouterConnectionTest: React.FC<AutoRouterConnectionTestProps> = ({
         Test Connection sends a minimal request to every configured tier, classifier, default, and embedding model. The
         classifier probe includes its reasoning effort override.
       </p>
+      {jevRequest && (
+        <div role="status" aria-label="JEV connection" className="rounded-lg border p-3 text-sm">
+          <strong>JEV Classifier</strong>
+          <p>
+            {jevResult.status === "pending" && "Testing JEV classification"}
+            {jevResult.status === "success" && "JEV classification succeeded"}
+            {jevResult.status === "error" && jevResult.error}
+          </p>
+        </div>
+      )}
       {targets.map((target, index) => {
         const result = results[index] ?? { status: "pending" };
         return (
@@ -100,3 +139,26 @@ const AutoRouterConnectionTest: React.FC<AutoRouterConnectionTestProps> = ({
 };
 
 export default AutoRouterConnectionTest;
+
+export function AutoRouterConnectionTestDialog({
+  open,
+  onClose,
+  testId,
+  ...props
+}: AutoRouterConnectionTestProps & { open: boolean; onClose: () => void; testId: number }) {
+  return (
+    <Dialog open={open} onOpenChange={(next) => !next && onClose()}>
+      <DialogContent className="max-h-[calc(100dvh-2rem)] overflow-y-auto sm:max-w-[700px]">
+        <DialogHeader>
+          <DialogTitle>Connection Test Results</DialogTitle>
+        </DialogHeader>
+        {open && <AutoRouterConnectionTest key={testId} {...props} />}
+        <DialogFooter>
+          <Button variant="outline" onClick={onClose}>
+            Close
+          </Button>
+        </DialogFooter>
+      </DialogContent>
+    </Dialog>
+  );
+}
diff --git a/ui/litellm-dashboard/src/components/add_model/build_auto_router_routing_test_request.test.ts b/ui/litellm-dashboard/src/components/add_model/build_auto_router_routing_test_request.test.ts
index 6678a3585c0..2aa02e40b5f 100644
--- a/ui/litellm-dashboard/src/components/add_model/build_auto_router_routing_test_request.test.ts
+++ b/ui/litellm-dashboard/src/components/add_model/build_auto_router_routing_test_request.test.ts
@@ -1,4 +1,9 @@
-import { buildAutoRouterRoutingTestRequest } from "./build_auto_router_routing_test_request";
+import { describe, expect, it } from "vitest";
+import {
+  buildAutoRouterRoutingTestRequest,
+  buildSavedJevConnectionTestRequest,
+  JEV_CONNECTION_TEST_PROMPT,
+} from "./build_auto_router_routing_test_request";
 import { ComplexityRouterConfigPayload } from "./build_complexity_router_config";
 
 const CONFIG = {
@@ -15,6 +20,36 @@ const params = {
 };
 
 describe("buildAutoRouterRoutingTestRequest", () => {
+  it.each(["object", "json"])("probes saved JEV %s configuration with custom tiers and team context", (format) => {
+    const config = {
+      classifier_type: "jev",
+      jev_classifier_config: { model: "jev-test", timeout_ms: 900 },
+      tiers: { QUICK: ["fast"], DEEP: ["strong"] },
+      tier_definitions: { QUICK: "Simple questions", DEEP: "Complex questions" },
+      fallback_tier: "DEEP",
+      classifier_context_window_size: 4,
+    };
+    expect(
+      buildSavedJevConnectionTestRequest(
+        format === "json" ? JSON.stringify(config) : config,
+        "strong",
+        "saved-router",
+        "team-1",
+      ),
+    ).toEqual({
+      prompt: JEV_CONNECTION_TEST_PROMPT,
+      complexity_router_config: config,
+      default_model: "strong",
+      router_name: "saved-router",
+      team_id: "team-1",
+    });
+  });
+  it.each([undefined, null, "not json", "[]", {}, { classifier_type: "llm", tiers: {} }, { classifier_type: "jev" }])(
+    "does not build a JEV probe for invalid or other classifier configurations: %j",
+    (config) => {
+      expect(buildSavedJevConnectionTestRequest(config)).toBeUndefined();
+    },
+  );
   it("sends the prompt with the config being edited", () => {
     const request = buildAutoRouterRoutingTestRequest(params);
 
diff --git a/ui/litellm-dashboard/src/components/add_model/build_auto_router_routing_test_request.ts b/ui/litellm-dashboard/src/components/add_model/build_auto_router_routing_test_request.ts
index 219dcbf6070..022bd8ad539 100644
--- a/ui/litellm-dashboard/src/components/add_model/build_auto_router_routing_test_request.ts
+++ b/ui/litellm-dashboard/src/components/add_model/build_auto_router_routing_test_request.ts
@@ -1,5 +1,38 @@
 import { AutoRouterRoutingTestRequest } from "../networking";
 import { ComplexityRouterConfigPayload } from "./build_complexity_router_config";
+import { z } from "zod";
+
+export const JEV_CONNECTION_TEST_PROMPT = "What is 2 plus 2?";
+
+export const buildSavedJevConnectionTestRequest = (
+  rawConfig: unknown,
+  defaultModel?: string,
+  routerName?: string,
+  teamId?: string,
+): AutoRouterRoutingTestRequest | undefined => {
+  const parsed: unknown =
+    typeof rawConfig === "string"
+      ? (() => {
+          try {
+            return JSON.parse(rawConfig) as unknown;
+          } catch {
+            return undefined;
+          }
+        })()
+      : rawConfig;
+  const result = z
+    .object({ classifier_type: z.literal("jev"), tiers: z.record(z.unknown()) })
+    .passthrough()
+    .safeParse(parsed);
+  if (!result.success) return undefined;
+  return {
+    prompt: JEV_CONNECTION_TEST_PROMPT,
+    complexity_router_config: result.data,
+    ...(defaultModel && { default_model: defaultModel }),
+    ...(routerName && { router_name: routerName }),
+    ...(teamId && { team_id: teamId }),
+  };
+};
 
 export interface BuildAutoRouterRoutingTestRequestParams {
   prompt: string;
diff --git a/ui/litellm-dashboard/src/components/add_model/build_complexity_router_config.test.ts b/ui/litellm-dashboard/src/components/add_model/build_complexity_router_config.test.ts
index 6e6e7a3c6cd..e03ec22b79f 100644
--- a/ui/litellm-dashboard/src/components/add_model/build_complexity_router_config.test.ts
+++ b/ui/litellm-dashboard/src/components/add_model/build_complexity_router_config.test.ts
@@ -1,3 +1,4 @@
+import { describe, expect, it } from "vitest";
 import {
   buildComplexityRouterConfig,
   getPlanModeTierError,
@@ -24,6 +25,11 @@ const tiers = {
 
 const baseParams: BuildComplexityRouterConfigParams = {
   tiers,
+  defaultModel: undefined,
+  planModeMinTier: undefined,
+  classificationExamples: undefined,
+  heuristicFirstMaxTier: undefined,
+  classificationMode: undefined,
   tierLabels: undefined,
   classifierType: "heuristic",
   classifierLlmConfig: undefined,
@@ -48,6 +54,94 @@ const baseParams: BuildComplexityRouterConfigParams = {
 };
 
 describe("buildComplexityRouterConfig", () => {
+  it("accepts built-in JEV defaults without an LLM classifier model", () => {
+    expect(getClassifierModelError({ classifier_type: "jev" })).toBeNull();
+  });
+
+  it.each([
+    { model: "" },
+    { model: "   " },
+    { timeout_ms: 0 },
+    { timeout_ms: 1.5 },
+    { timeout_ms: Number.NaN },
+    { circuit_breaker_cooldown_seconds: -1 },
+    { circuit_breaker_cooldown_seconds: Number.POSITIVE_INFINITY },
+  ])("rejects invalid JEV settings before saving or testing: %j", (patch) => {
+    expect(
+      getClassifierModelError({
+        classifier_type: "jev",
+        jev_classifier_config: { model: "jev-latest", timeout_ms: 3000, ...patch },
+      }),
+    ).toBe("Enter a JEV model, a positive whole-number timeout and a positive cooldown");
+  });
+
+  it.each([false, true])("serializes JEV with shared context and no LLM config, custom tiers: %s", (custom) => {
+    const config = buildComplexityRouterConfig({
+      ...baseParams,
+      classifierType: "jev",
+      jevClassifierConfig: {
+        model: "jev-test",
+        timeout_ms: 4500,
+        instructions: "  Choose the configured tier  ",
+        circuit_breaker_enabled: false,
+        circuit_breaker_cooldown_seconds: 12.5,
+      },
+      classifierLlmConfig: { model: "stale", timeout_ms: 30 },
+      classificationPrompt: "stale prompt",
+      classificationExamples: "stale examples",
+      classifierContextWindowSize: 4,
+      classifierContextBudgetChars: 2000,
+      classifierContextIncludeAssistantTurns: true,
+      classifierFallback: "default_model",
+      ...(custom && {
+        customTierSet: {
+          tiers: [
+            { id: "quick", name: "QUICK", definition: "Short answers", models: ["fast"] },
+            { id: "review", name: "REVIEW", definition: "Deep review", models: ["strong"] },
+          ],
+          fallback_tier_id: "quick",
+        },
+      }),
+    });
+    expect(config.classifier_type).toBe("jev");
+    expect(config.jev_classifier_config).toEqual({
+      model: "jev-test",
+      timeout_ms: 4500,
+      instructions: "Choose the configured tier",
+      circuit_breaker_enabled: false,
+      circuit_breaker_cooldown_seconds: 12.5,
+    });
+    expect(config.classifier_context_window_size).toBe(4);
+    expect(config.classifier_context_budget_chars).toBe(2000);
+    expect(config.classifier_context_include_assistant_turns).toBe(true);
+    expect(config).not.toHaveProperty("classifier_llm_config");
+    expect(config).not.toHaveProperty("classification_prompt");
+    expect(config).not.toHaveProperty("classification_examples");
+    if (custom) {
+      expect(config.tiers).toEqual({ QUICK: ["fast"], REVIEW: ["strong"] });
+      expect(config.fallback_tier).toBe("QUICK");
+    } else {
+      expect(config.classifier_fallback).toBe("default_model");
+      expect(config.tiers).toEqual(tiers);
+    }
+  });
+
+  it("omits blank JEV instructions and ignores stale JEV settings when saving LLM", () => {
+    const jev = buildComplexityRouterConfig({
+      ...baseParams,
+      classifierType: "jev",
+      jevClassifierConfig: { model: "jev-latest", timeout_ms: 3000, instructions: "  " },
+    });
+    expect(jev.jev_classifier_config).toEqual({ model: "jev-latest", timeout_ms: 3000 });
+    const llm = buildComplexityRouterConfig({
+      ...baseParams,
+      classifierType: "llm",
+      classifierLlmConfig: { model: "judge", timeout_ms: 1000 },
+      jevClassifierConfig: jev.jev_classifier_config,
+    });
+    expect(llm).not.toHaveProperty("jev_classifier_config");
+  });
+
   it.each(["capability", "llm_v2", "heuristic"] as const)(
     "disables the removed overrides only for forecast creates: %s",
     (classifierType) => {
diff --git a/ui/litellm-dashboard/src/components/add_model/build_complexity_router_config.ts b/ui/litellm-dashboard/src/components/add_model/build_complexity_router_config.ts
index 8a377c17ad7..0b844b8ddd5 100644
--- a/ui/litellm-dashboard/src/components/add_model/build_complexity_router_config.ts
+++ b/ui/litellm-dashboard/src/components/add_model/build_complexity_router_config.ts
@@ -6,6 +6,11 @@ import {
 } from "./forecast_classifier_config";
 import type { ModelGroup } from "../llm_calls/fetch_models";
 import { KeywordTierRule } from "./KeywordTierRules";
+import {
+  type JevClassifierConfig,
+  jevClassifierConfigSchema,
+  normalizeJevClassifierConfig,
+} from "./jev_classifier_config";
 import {
   type CustomTierSet,
   type TierRow,
@@ -44,6 +49,7 @@ import {
   effectiveTierLabel,
   heuristicScoringRoleFor,
   usesLlmClassifier,
+  usesClassifierContext,
 } from "./ComplexityRouterConfig";
 
 export type ClassifierVisionConfig = { enabled?: boolean; max_images?: number };
@@ -133,7 +139,7 @@ const scorerKnobPayload = ({
 };
 
 export interface StoredComplexityRouterConfig {
-  tiers?: Partial<Record<keyof ComplexityTiers, unknown>>;
+  tiers?: Record<string, unknown>;
   enable_non_reasoning_tier?: boolean;
   tier_model_configs?: unknown;
   default_model?: string | null;
@@ -147,6 +153,7 @@ export interface StoredComplexityRouterConfig {
   capability_classifier_config?: unknown;
   llm_v2_config?: unknown;
   classifier_llm_config?: ClassifierLLMConfig;
+  jev_classifier_config?: unknown;
   classifier_context_window_size?: unknown;
   classifier_context_budget_chars?: unknown;
   classifier_context_include_assistant_turns?: unknown;
@@ -185,6 +192,7 @@ export interface BuildComplexityRouterConfigParams {
   capabilityClassifierConfig?: CapabilitySettings;
   llmV2Config?: FuseSettings;
   classifierLlmConfig: ClassifierLLMConfigWire | undefined;
+  jevClassifierConfig?: JevClassifierConfig;
   classifierContextWindowSize: number | undefined;
   classifierContextBudgetChars: number | undefined;
   classifierContextIncludeAssistantTurns: boolean | undefined;
@@ -251,6 +259,7 @@ export interface ComplexityRouterConfigPayload {
   capability_classifier_config?: CapabilitySettings;
   llm_v2_config?: FuseSettings;
   classifier_llm_config?: ClassifierLLMConfig;
+  jev_classifier_config?: JevClassifierConfig;
   classifier_context_window_size?: number;
   classifier_context_budget_chars?: number;
   classifier_context_per_turn_chars?: number;
@@ -356,11 +365,16 @@ export const getKeywordTierRulesError = (
   return `Keyword rule(s) ${orphaned.join(", ")} route to a tier this router no longer has`;
 };
 
-// An edited tier set forces the LLM classifier, so the model requirement follows the EFFECTIVE type.
-// Both forms' submit gates and their submit handlers read this one answer so they cannot drift.
 export const getClassifierModelError = (
-  config: Pick<ComplexityRouterConfigValue, "custom_tier_set" | "classifier_type" | "classifier_llm_config">,
+  config: Pick<
+    ComplexityRouterConfigValue,
+    "custom_tier_set" | "classifier_type" | "classifier_llm_config" | "jev_classifier_config"
+  >,
 ): string | null => {
+  if (effectiveClassifierType(config) === "jev") {
+    const parsed = jevClassifierConfigSchema.safeParse(config.jev_classifier_config ?? {});
+    return parsed.success ? null : "Enter a JEV model, a positive whole-number timeout and a positive cooldown";
+  }
   if (!usesLlmClassifier(effectiveClassifierType(config)) || config.classifier_llm_config?.model) return null;
   return config.custom_tier_set
     ? "Please select a classifier model: an edited tier set routes with the LLM classifier"
@@ -395,6 +409,7 @@ export const getSemanticConfigError = ({
 };
 
 interface CustomTierWireFieldInputs {
+  classifierType?: ClassifierType;
   classifierLlmConfig: ClassifierLLMConfigWire | undefined;
   planModeMinTierId: string | undefined;
   classificationPrompt: string | undefined;
@@ -403,7 +418,13 @@ interface CustomTierWireFieldInputs {
 
 export const customTierWireFields = (
   customTierSet: CustomTierSet,
-  { classifierLlmConfig, planModeMinTierId, classificationPrompt, classificationExamples }: CustomTierWireFieldInputs,
+  {
+    classifierType,
+    classifierLlmConfig,
+    planModeMinTierId,
+    classificationPrompt,
+    classificationExamples,
+  }: CustomTierWireFieldInputs,
 ): Partial<ComplexityRouterConfigPayload> => {
   const rows = customTierSet.tiers;
   const fallback = tierRowById(rows, customTierSet.fallback_tier_id);
@@ -412,27 +433,30 @@ export const customTierWireFields = (
     tiers: Object.fromEntries(rows.map((row) => [activeTierName(row), row.models])),
     tier_definitions: tierDefinitionsFromRows(rows),
     ...(fallback && { fallback_tier: activeTierName(fallback) }),
-    classifier_type: "llm",
+    classifier_type: classifierType === "jev" ? "jev" : "llm",
     // Rebuilt from the fields an edited tier set allows. The backend rejects system_prompt and
     // classification_rubric beside tier_definitions, and both live inside this object rather than at
     // the top level the omit list covers. The opening instructions ride classification_prompt below.
-    ...(classifierLlmConfig && {
-      classifier_llm_config: {
-        model: classifierLlmConfig.model,
-        timeout_ms: classifierLlmConfig.timeout_ms,
-        ...(classifierLlmConfig.circuit_breaker_enabled !== undefined && {
-          circuit_breaker_enabled: classifierLlmConfig.circuit_breaker_enabled,
-        }),
-        ...(classifierLlmConfig.circuit_breaker_cooldown_seconds !== undefined && {
-          circuit_breaker_cooldown_seconds: classifierLlmConfig.circuit_breaker_cooldown_seconds,
-        }),
-        ...(classifierLlmConfig.reasoning_effort && { reasoning_effort: classifierLlmConfig.reasoning_effort }),
-        ...(classifierLlmConfig.vision && { vision: classifierLlmConfig.vision }),
-      },
-    }),
+    ...(classifierType !== "jev" &&
+      classifierLlmConfig && {
+        classifier_llm_config: {
+          model: classifierLlmConfig.model,
+          timeout_ms: classifierLlmConfig.timeout_ms,
+          ...(classifierLlmConfig.circuit_breaker_enabled !== undefined && {
+            circuit_breaker_enabled: classifierLlmConfig.circuit_breaker_enabled,
+          }),
+          ...(classifierLlmConfig.circuit_breaker_cooldown_seconds !== undefined && {
+            circuit_breaker_cooldown_seconds: classifierLlmConfig.circuit_breaker_cooldown_seconds,
+          }),
+          ...(classifierLlmConfig.reasoning_effort && { reasoning_effort: classifierLlmConfig.reasoning_effort }),
+          ...(classifierLlmConfig.vision && { vision: classifierLlmConfig.vision }),
+        },
+      }),
     session_affinity: false,
-    ...(classificationPrompt?.trim() && { classification_prompt: classificationPrompt.trim() }),
-    ...(classificationExamples?.trim() && { classification_examples: classificationExamples.trim() }),
+    ...(classifierType !== "jev" &&
+      classificationPrompt?.trim() && { classification_prompt: classificationPrompt.trim() }),
+    ...(classifierType !== "jev" &&
+      classificationExamples?.trim() && { classification_examples: classificationExamples.trim() }),
     ...(floor && { plan_mode_min_tier: activeTierName(floor) }),
   };
 };
@@ -521,7 +545,7 @@ const classifierWireFields = (
     | "classifierContextIncludeAssistantTurns"
   >,
 ): Partial<ComplexityRouterConfigPayload> => {
-  const supportsFallback = usesLlmClassifier(effectiveType) && !isForecastClassifier(effectiveType);
+  const supportsFallback = usesClassifierContext(effectiveType) && !isForecastClassifier(effectiveType);
   return {
     ...(usesLlmClassifier(effectiveType) &&
       classifierLlmConfig && {
@@ -534,15 +558,15 @@ const classifierWireFields = (
       heuristicFirstMaxTier?.trim() && { heuristic_first_max_tier: heuristicFirstMaxTier }),
     ...(effectiveType === "hybrid" &&
       hybridBoundaryMargin !== undefined && { hybrid_boundary_margin: hybridBoundaryMargin }),
-    ...(usesLlmClassifier(effectiveType) &&
+    ...(usesClassifierContext(effectiveType) &&
       classifierContextWindowSize !== undefined && {
         classifier_context_window_size: classifierContextWindowSize,
       }),
-    ...(usesLlmClassifier(effectiveType) &&
+    ...(usesClassifierContext(effectiveType) &&
       classifierContextBudgetChars !== undefined && {
         classifier_context_budget_chars: classifierContextBudgetChars,
       }),
-    ...(usesLlmClassifier(effectiveType) &&
+    ...(usesClassifierContext(effectiveType) &&
       classifierContextIncludeAssistantTurns !== undefined && {
         classifier_context_include_assistant_turns: classifierContextIncludeAssistantTurns,
       }),
@@ -560,6 +584,7 @@ export const buildComplexityRouterConfig = ({
   capabilityClassifierConfig,
   llmV2Config,
   classifierLlmConfig,
+  jevClassifierConfig,
   classifierContextWindowSize,
   classifierContextBudgetChars,
   classifierContextIncludeAssistantTurns,
@@ -625,9 +650,7 @@ export const buildComplexityRouterConfig = ({
     classifierContextBudgetChars,
     classifierContextIncludeAssistantTurns,
   };
-  // An edited tier set forces the LLM classifier, so llm-only inputs must survive a classifier_type
-  // the form never rewrote. The UI gates the same controls on this, not on the raw value.
-  const effectiveType: ClassifierType = customTierSet ? "llm" : classifierType;
+  const effectiveType = effectiveClassifierType({ custom_tier_set: customTierSet, classifier_type: classifierType });
   const forecast = isForecastClassifier(effectiveType);
 
   const supportsOpeningPrompt = !customTierSet && !forecast && usesLlmClassifier(effectiveType);
@@ -640,6 +663,7 @@ export const buildComplexityRouterConfig = ({
     ...(planModeMinTier?.trim() && { plan_mode_min_tier: planModeMinTier }),
     ...(cleanedTierLabels && { tier_labels: cleanedTierLabels }),
     classifier_type: classifierType,
+    ...(effectiveType === "jev" && { jev_classifier_config: normalizeJevClassifierConfig(jevClassifierConfig) }),
     ...classifierWireFields(effectiveType, classifierInputs),
     ...(effectiveType === "capability" &&
       capabilityClassifierConfig && { capability_classifier_config: capabilityClassifierConfig }),
@@ -700,6 +724,7 @@ export const buildComplexityRouterConfig = ({
     Object.entries(payload).filter(([key]) => !CUSTOM_TIER_STRIPPED_KEYS.includes(key)),
   ) as ComplexityRouterConfigPayload;
   const customTierInputs: CustomTierWireFieldInputs = {
+    classifierType: effectiveType,
     classifierLlmConfig,
     planModeMinTierId: planModeMinTier,
     classificationPrompt,
diff --git a/ui/litellm-dashboard/src/components/add_model/classifier_type_transition.test.ts b/ui/litellm-dashboard/src/components/add_model/classifier_type_transition.test.ts
index e3fe00d2bc8..4a0b29ecee3 100644
--- a/ui/litellm-dashboard/src/components/add_model/classifier_type_transition.test.ts
+++ b/ui/litellm-dashboard/src/components/add_model/classifier_type_transition.test.ts
@@ -1,6 +1,7 @@
 import { describe, expect, it } from "vitest";
-import type { ComplexityRouterConfigValue } from "./ComplexityRouterConfig";
+import { effectiveClassifierType, type ComplexityRouterConfigValue } from "./ComplexityRouterConfig";
 import { transitionClassifierType } from "./classifier_type_transition";
+import { applyTierSetAction } from "./tier_set_actions";
 
 const standard: ComplexityRouterConfigValue = {
   classifier_type: "llm",
@@ -13,6 +14,44 @@ const standard: ComplexityRouterConfigValue = {
 };
 
 describe("transitionClassifierType", () => {
+  it("switches between LLM and JEV without losing shared routing settings or leaking opposite config", () => {
+    const initial = {
+      ...standard,
+      classification_prompt: "LLM only",
+      classification_examples: "LLM examples",
+      enable_non_reasoning_tier: true,
+      tiers: { ...standard.tiers, NON_REASONING: ["fast"] },
+      plan_mode_min_tier: "NON_REASONING",
+      adaptive: true,
+    };
+    const jev = transitionClassifierType(initial, "jev");
+    expect(jev).toMatchObject({
+      classifier_type: "jev",
+      jev_classifier_config: { model: "jev-latest", timeout_ms: 3000 },
+      classifier_context_window_size: 8,
+      classifier_context_budget_chars: 16000,
+      classifier_context_include_assistant_turns: true,
+      classifier_fallback: "default_model",
+      adaptive: true,
+      enable_non_reasoning_tier: true,
+      plan_mode_min_tier: "NON_REASONING",
+      tiers: initial.tiers,
+    });
+    expect(jev.classifier_llm_config).toBeUndefined();
+    expect(jev.classification_prompt).toBeUndefined();
+    expect(jev.classification_examples).toBeUndefined();
+    const custom = applyTierSetAction(jev, [], { kind: "patch", id: "SIMPLE", patch: { name: "QUICK" } }).value;
+    expect(effectiveClassifierType(custom)).toBe("jev");
+    const restored = applyTierSetAction(custom, [], { kind: "restore" }).value;
+    expect(effectiveClassifierType(restored)).toBe("jev");
+    expect(restored.jev_classifier_config).toEqual(jev.jev_classifier_config);
+    const llm = transitionClassifierType(custom, "llm");
+    expect(llm.jev_classifier_config).toBeUndefined();
+    expect(llm.classifier_llm_config).toMatchObject({ model: "" });
+    expect(llm.custom_tier_set).toEqual(custom.custom_tier_set);
+    expect(llm.classifier_context_window_size).toBe(8);
+  });
+
   it.each(["heuristic_first", "hybrid"] as const)("keeps existing LLM settings when switching to %s", (target) => {
     const result = transitionClassifierType(standard, target);
     const expectedSettings = {
diff --git a/ui/litellm-dashboard/src/components/add_model/classifier_type_transition.ts b/ui/litellm-dashboard/src/components/add_model/classifier_type_transition.ts
index df87e2854e3..ba758eac471 100644
--- a/ui/litellm-dashboard/src/components/add_model/classifier_type_transition.ts
+++ b/ui/litellm-dashboard/src/components/add_model/classifier_type_transition.ts
@@ -8,7 +8,9 @@ import {
   DEFAULT_HYBRID_BOUNDARY_MARGIN,
   NEW_CLASSIFIER_CLASSIFICATION_RUBRIC,
   usesLlmClassifier,
+  usesClassifierContext,
 } from "./ComplexityRouterConfig";
+import { defaultJevClassifierConfig } from "./jev_classifier_config";
 import { isForecastClassifier, prepareForecastClassifier } from "./forecast_classifier_config";
 import { nonReasoningTierFields } from "./nonReasoningTierFields";
 
@@ -22,22 +24,29 @@ export const transitionClassifierType = (
   const judgeConfig = value.classifier_llm_config ?? { model: "", timeout_ms: DEFAULT_CLASSIFIER_TIMEOUT_MS };
   const nextValue: ComplexityRouterConfigValue = {
     ...value,
+    jev_classifier_config:
+      classifierType === "jev" ? value.jev_classifier_config ?? defaultJevClassifierConfig() : undefined,
+    classification_prompt: classifierType === "jev" ? undefined : value.classification_prompt,
+    classification_examples: classifierType === "jev" ? undefined : value.classification_examples,
     classifier_llm_config: usesLlmClassifier(classifierType)
       ? {
           ...judgeConfig,
           ...(startsLlmRubric && { classification_rubric: NEW_CLASSIFIER_CLASSIFICATION_RUBRIC }),
         }
       : undefined,
-    classifier_context_window_size: usesLlmClassifier(classifierType)
+    classifier_context_window_size: usesClassifierContext(classifierType)
       ? value.classifier_context_window_size ?? DEFAULT_CLASSIFIER_CONTEXT_WINDOW_SIZE
       : undefined,
-    classifier_context_budget_chars: usesLlmClassifier(classifierType)
+    classifier_context_budget_chars: usesClassifierContext(classifierType)
       ? value.classifier_context_budget_chars ?? DEFAULT_CLASSIFIER_CONTEXT_BUDGET_CHARS
       : undefined,
-    classifier_context_include_assistant_turns: usesLlmClassifier(classifierType)
+    classifier_context_per_turn_chars: usesClassifierContext(classifierType)
+      ? value.classifier_context_per_turn_chars
+      : undefined,
+    classifier_context_include_assistant_turns: usesClassifierContext(classifierType)
       ? value.classifier_context_include_assistant_turns
       : undefined,
-    classifier_fallback: usesLlmClassifier(classifierType) ? value.classifier_fallback : undefined,
+    classifier_fallback: usesClassifierContext(classifierType) ? value.classifier_fallback : undefined,
     heuristic_first_max_tier:
       classifierType === "heuristic_first"
         ? value.heuristic_first_max_tier ?? DEFAULT_HEURISTIC_FIRST_MAX_TIER
diff --git a/ui/litellm-dashboard/src/components/add_model/classifier_types.ts b/ui/litellm-dashboard/src/components/add_model/classifier_types.ts
new file mode 100644
index 00000000000..ec88166ed2e
--- /dev/null
+++ b/ui/litellm-dashboard/src/components/add_model/classifier_types.ts
@@ -0,0 +1,15 @@
+export type ClassifierType =
+  | "heuristic"
+  | "heuristic_v2"
+  | "llm"
+  | "jev"
+  | "heuristic_first"
+  | "hybrid"
+  | "capability"
+  | "llm_v2";
+
+export const usesLlmClassifier = (classifierType: ClassifierType): boolean =>
+  (["llm", "heuristic_first", "hybrid", "capability", "llm_v2"] as const).some((type) => type === classifierType);
+
+export const usesClassifierContext = (classifierType: ClassifierType): boolean =>
+  classifierType === "jev" || usesLlmClassifier(classifierType);
diff --git a/ui/litellm-dashboard/src/components/add_model/jev_classifier_config.ts b/ui/litellm-dashboard/src/components/add_model/jev_classifier_config.ts
new file mode 100644
index 00000000000..a1481c9c2e8
--- /dev/null
+++ b/ui/litellm-dashboard/src/components/add_model/jev_classifier_config.ts
@@ -0,0 +1,28 @@
+import { z } from "zod";
+
+export const jevClassifierConfigSchema = z.object({
+  model: z.string().trim().min(1).default("jev-latest"),
+  timeout_ms: z.number().int().positive().default(3000),
+  instructions: z
+    .string()
+    .nullish()
+    .transform((value) => value ?? undefined),
+  circuit_breaker_enabled: z.boolean().optional(),
+  circuit_breaker_cooldown_seconds: z.number().finite().positive().optional(),
+});
+
+export type JevClassifierConfig = z.infer<typeof jevClassifierConfigSchema>;
+
+export const defaultJevClassifierConfig = (): JevClassifierConfig => jevClassifierConfigSchema.parse({});
+
+export const normalizeJevClassifierConfig = (
+  config: JevClassifierConfig = defaultJevClassifierConfig(),
+): JevClassifierConfig => ({
+  model: config.model.trim(),
+  timeout_ms: config.timeout_ms,
+  ...(config.instructions?.trim() && { instructions: config.instructions.trim() }),
+  ...(config.circuit_breaker_enabled !== undefined && { circuit_breaker_enabled: config.circuit_breaker_enabled }),
+  ...(config.circuit_breaker_cooldown_seconds !== undefined && {
+    circuit_breaker_cooldown_seconds: config.circuit_breaker_cooldown_seconds,
+  }),
+});
diff --git a/ui/litellm-dashboard/src/components/add_model/nonReasoningTierFields.ts b/ui/litellm-dashboard/src/components/add_model/nonReasoningTierFields.ts
index 92a665a199c..d278518000c 100644
--- a/ui/litellm-dashboard/src/components/add_model/nonReasoningTierFields.ts
+++ b/ui/litellm-dashboard/src/components/add_model/nonReasoningTierFields.ts
@@ -12,7 +12,7 @@ export const nonReasoningTierFields = (
   classifierType: ClassifierType,
   value: ComplexityRouterConfigValue,
 ): Pick<ComplexityRouterConfigValue, "enable_non_reasoning_tier" | "tiers" | "plan_mode_min_tier"> => {
-  if (classifierType === "llm") {
+  if (classifierType === "llm" || classifierType === "jev") {
     return {
       enable_non_reasoning_tier: value.enable_non_reasoning_tier,
       tiers: value.tiers,
diff --git a/ui/litellm-dashboard/src/components/add_model/tier_rows.ts b/ui/litellm-dashboard/src/components/add_model/tier_rows.ts
index b4c6b2cb81e..dff051e5674 100644
--- a/ui/litellm-dashboard/src/components/add_model/tier_rows.ts
+++ b/ui/litellm-dashboard/src/components/add_model/tier_rows.ts
@@ -145,7 +145,7 @@ export const CUSTOM_TIER_RESTRICTIONS = {
   heuristicClassifier: {
     omit: ["heuristic_first_max_tier", "hybrid_boundary_margin"],
     reason:
-      "The heuristic scorer only produces the built-in tiers, so an edited set needs the LLM classifier. " +
+      "The heuristic scorer only produces the built-in tiers, so an edited set needs the LLM or JEV classifier. " +
       "Heuristic first and hybrid are out for the same reason: their local scorer decides the traffic it is sure of",
   },
   heuristicScoring: {
diff --git a/ui/litellm-dashboard/src/components/edit_auto_router/build_updated_complexity_router_config.test.ts b/ui/litellm-dashboard/src/components/edit_auto_router/build_updated_complexity_router_config.test.ts
index 4ae6efbb12d..2a3804b0307 100644
--- a/ui/litellm-dashboard/src/components/edit_auto_router/build_updated_complexity_router_config.test.ts
+++ b/ui/litellm-dashboard/src/components/edit_auto_router/build_updated_complexity_router_config.test.ts
@@ -1,4 +1,6 @@
 import { describe, expect, it } from "vitest";
+import { transitionClassifierType } from "../add_model/classifier_type_transition";
+import { effectiveClassifierType } from "../add_model/ComplexityRouterConfig";
 
 import {
   MANAGED_COMPLEXITY_ROUTER_KEYS,
@@ -46,6 +48,62 @@ const hydratedState: KeywordMatchingState = {
 };
 
 describe("buildUpdatedComplexityRouterConfig keyword matching", () => {
+  it("hydrates nullable JEV instructions without resetting the server configuration", () => {
+    const stored = {
+      classifier_type: "jev" as const,
+      jev_classifier_config: {
+        model: "jev-configured",
+        timeout_ms: 6100,
+        instructions: null,
+        circuit_breaker_enabled: false,
+      },
+      tiers: FORM_VALUE.tiers,
+    };
+    const saved = buildUpdatedComplexityRouterConfig(stored, hydrateComplexityRouterConfig(stored, undefined));
+    expect(saved.jev_classifier_config).toEqual({
+      model: "jev-configured",
+      timeout_ms: 6100,
+      circuit_breaker_enabled: false,
+    });
+  });
+  it.each([false, true])("round trips JEV settings and preserves unmanaged fields, custom: %s", (custom) => {
+    const stored = {
+      ...(custom ? storedCustomConfig() : STORED),
+      classifier_llm_config: { model: "stale-judge", timeout_ms: 3000 },
+      classifier_type: "jev" as const,
+      jev_classifier_config: {
+        model: "jev-test",
+        timeout_ms: 4100,
+        instructions: "Judge the request",
+        circuit_breaker_enabled: false,
+        circuit_breaker_cooldown_seconds: 10.5,
+      },
+      classifier_context_window_size: 7,
+      classifier_context_budget_chars: 9000,
+      classifier_context_include_assistant_turns: true,
+      some_future_backend_key: { nested: true },
+    };
+    const hydrated = hydrateComplexityRouterConfig(stored, undefined);
+    expect(effectiveClassifierType(hydrated)).toBe("jev");
+    expect(hydrated.classifier_llm_config).toBeUndefined();
+    expect(hydrated.jev_classifier_config).toEqual(stored.jev_classifier_config);
+    const saved = buildUpdatedComplexityRouterConfig(stored, hydrated);
+    expect(saved).toMatchObject({
+      classifier_type: "jev",
+      jev_classifier_config: stored.jev_classifier_config,
+      classifier_context_window_size: 7,
+      classifier_context_budget_chars: 9000,
+      classifier_context_include_assistant_turns: true,
+      some_future_backend_key: { nested: true },
+    });
+    expect(saved).not.toHaveProperty("classifier_llm_config");
+    const reloaded = hydrateComplexityRouterConfig(saved, undefined);
+    expect(reloaded.jev_classifier_config).toEqual(hydrated.jev_classifier_config);
+    expect(effectiveClassifierType(reloaded)).toBe("jev");
+    const llm = buildUpdatedComplexityRouterConfig(saved, transitionClassifierType(reloaded, "llm"));
+    expect(llm).not.toHaveProperty("jev_classifier_config");
+  });
+
   it.each(["capability", "llm_v2", "heuristic"] as const)(
     "handles enabled stored overrides when editing %s with or without keyword form state",
     (classifier_type) => {
@@ -700,7 +758,12 @@ describe("managed keys survive an untouched open-and-save", () => {
   // tier_definitions and fallback_tier cannot sit beside heuristic_first, which this fixture uses,
   // and hybrid_boundary_margin belongs to the sibling hybrid type, so no single stored config can
   // hold every managed key. Each gets its own round trip below.
-  const KEYS_ANOTHER_CLASSIFIER_TYPE_OWNS = new Set(["tier_definitions", "fallback_tier", "hybrid_boundary_margin"]);
+  const KEYS_ANOTHER_CLASSIFIER_TYPE_OWNS = new Set([
+    "tier_definitions",
+    "fallback_tier",
+    "hybrid_boundary_margin",
+    "jev_classifier_config",
+  ]);
 
   // The stall keys are rejected beside the session pinning and user-turn classification this
   // fixture sets, so they get their own round trip below rather than widening this one.
diff --git a/ui/litellm-dashboard/src/components/edit_auto_router/edit_auto_router_modal.tsx b/ui/litellm-dashboard/src/components/edit_auto_router/edit_auto_router_modal.tsx
index e25c7f07dd7..63ad5deb21c 100644
--- a/ui/litellm-dashboard/src/components/edit_auto_router/edit_auto_router_modal.tsx
+++ b/ui/litellm-dashboard/src/components/edit_auto_router/edit_auto_router_modal.tsx
@@ -1,4 +1,5 @@
 import AutoRouterClassifierTabs from "../add_model/AutoRouterClassifierTabs";
+import { defaultJevClassifierConfig, jevClassifierConfigSchema } from "../add_model/jev_classifier_config";
 import type { StoredComplexityRouterConfig } from "../add_model/build_complexity_router_config";
 export type { StoredComplexityRouterConfig } from "../add_model/build_complexity_router_config";
 import {
@@ -129,7 +130,12 @@ export const hydrateComplexityRouterConfig = (
     classifier_type: parsedConfig.classifier_type || "heuristic",
     capability_classifier_config: capabilitySettingsSchema.safeParse(parsedConfig.capability_classifier_config).data,
     llm_v2_config: fuseSettingsSchema.safeParse(parsedConfig.llm_v2_config).data,
-    classifier_llm_config: parsedConfig.classifier_llm_config,
+    classifier_llm_config: parsedConfig.classifier_type === "jev" ? undefined : parsedConfig.classifier_llm_config,
+    jev_classifier_config:
+      parsedConfig.classifier_type === "jev"
+        ? jevClassifierConfigSchema.safeParse(parsedConfig.jev_classifier_config ?? {}).data ??
+          defaultJevClassifierConfig()
+        : undefined,
     classifier_context_window_size:
       typeof parsedConfig.classifier_context_window_size === "number"
         ? parsedConfig.classifier_context_window_size
@@ -219,6 +225,7 @@ export const MANAGED_COMPLEXITY_ROUTER_KEYS = new Set([
   "capability_classifier_config",
   "llm_v2_config",
   "classifier_llm_config",
+  "jev_classifier_config",
   "classifier_context_window_size",
   "classifier_context_budget_chars",
   "classifier_context_include_assistant_turns",
@@ -329,6 +336,7 @@ export const buildUpdatedComplexityRouterConfig = (
     classificationMode: value.classification_mode,
     tierLabels: value.tier_labels,
     classifierType: value.classifier_type,
+    jevClassifierConfig: value.jev_classifier_config,
     capabilityClassifierConfig: value.capability_classifier_config,
     llmV2Config: value.llm_v2_config,
     classifierLlmConfig: value.classifier_llm_config,
diff --git a/ui/litellm-dashboard/src/components/model_info_view.tsx b/ui/litellm-dashboard/src/components/model_info_view.tsx
index 77c9d700c69..4e5ba81f2a4 100644
--- a/ui/litellm-dashboard/src/components/model_info_view.tsx
+++ b/ui/litellm-dashboard/src/components/model_info_view.tsx
@@ -15,6 +15,7 @@ import { copyToClipboard as utilCopyToClipboard } from "../utils/dataUtils";
 import { stripMaskedSecrets } from "../utils/maskedSecretUtils";
 import { truncateString } from "../utils/textUtils";
 import AutoRouterConnectionTest from "./add_model/auto_router_connection_test";
+import { buildSavedJevConnectionTestRequest } from "./add_model/build_auto_router_routing_test_request";
 import { AutoRouterTestTarget, buildComplexityRouterTestTargets } from "./add_model/build_auto_router_test_targets";
 import {
   hasAutoRouterEditor,
@@ -846,6 +847,12 @@ export default function ModelInfoView({
               key={autoRouterTestId}
               accessToken={accessToken}
               targets={autoRouterTestTargets}
+              jevRequest={buildSavedJevConnectionTestRequest(
+                (localModelData ?? modelData)?.litellm_params?.complexity_router_config,
+                (localModelData ?? modelData)?.litellm_params?.complexity_router_default_model,
+                (localModelData ?? modelData)?.model_name,
+                (localModelData ?? modelData)?.model_info?.team_id,
+              )}
             />
           )}
           <DialogFooter>
diff --git a/ui/litellm-dashboard/src/components/networking.tsx b/ui/litellm-dashboard/src/components/networking.tsx
index 80b4a72649d..2358e1baf9a 100644
--- a/ui/litellm-dashboard/src/components/networking.tsx
+++ b/ui/litellm-dashboard/src/components/networking.tsx
@@ -2326,7 +2326,7 @@ export const testModelGroupConnection = async (
 
 export interface AutoRouterRoutingTestRequest {
   prompt: string;
-  complexity_router_config: ComplexityRouterConfigPayload;
+  complexity_router_config: ComplexityRouterConfigPayload | Record<string, unknown>;
   default_model?: string;
   router_name?: string;
   team_id?: string;
diff --git a/ui/litellm-dashboard/src/components/view_logs/LogDetailsDrawer/RoutingDecisionCard.test.tsx b/ui/litellm-dashboard/src/components/view_logs/LogDetailsDrawer/RoutingDecisionCard.test.tsx
index fd1777f802c..474b2e116b7 100644
--- a/ui/litellm-dashboard/src/components/view_logs/LogDetailsDrawer/RoutingDecisionCard.test.tsx
+++ b/ui/litellm-dashboard/src/components/view_logs/LogDetailsDrawer/RoutingDecisionCard.test.tsx
@@ -103,7 +103,7 @@ describe("RoutingDecisionCard", () => {
         }}
       />,
     );
-    expect(screen.getByText("Default model, LLM classifier failed")).toBeInTheDocument();
+    expect(screen.getByText("Default model, classifier failed")).toBeInTheDocument();
     expect(screen.queryByText("Tier")).not.toBeInTheDocument();
   });
 
@@ -120,7 +120,7 @@ describe("RoutingDecisionCard", () => {
         }}
       />,
     );
-    expect(screen.getByText("Fallback tier, LLM classifier failed")).toBeInTheDocument();
+    expect(screen.getByText("Fallback tier, classifier failed")).toBeInTheDocument();
     expect(screen.getByText("SECURITY_REVIEW")).toBeInTheDocument();
   });
 
diff --git a/ui/litellm-dashboard/src/components/view_logs/LogDetailsDrawer/RoutingDecisionCard.tsx b/ui/litellm-dashboard/src/components/view_logs/LogDetailsDrawer/RoutingDecisionCard.tsx
index cf2c71e64c6..7bbf18e16ed 100644
--- a/ui/litellm-dashboard/src/components/view_logs/LogDetailsDrawer/RoutingDecisionCard.tsx
+++ b/ui/litellm-dashboard/src/components/view_logs/LogDetailsDrawer/RoutingDecisionCard.tsx
@@ -24,6 +24,9 @@ export interface RoutingDecision {
   matched_keyword?: string;
   escalation_keyword?: string;
   classifier_model?: string;
+  classifier_confidence?: number;
+  classifier_probabilities?: Record<string, number>;
+  classifier_cost?: number;
   escalated?: boolean;
   tier_boundaries?: RoutingDecisionTierBoundaries;
   reasoning_override_min_score?: number;
@@ -97,8 +100,8 @@ const CONSTANT_CAUSE_LABELS: Record<string, string> = {
   quality_tier: "Quality tier mapping",
   bandit: "Adaptive bandit",
   default_fallback: "Default model, no route matched",
-  classifier_fallback: "Fallback tier, LLM classifier failed",
-  default_model_fallback: "Default model, LLM classifier failed",
+  classifier_fallback: "Fallback tier, classifier failed",
+  default_model_fallback: "Default model, classifier failed",
 };
 
 function describeCause(decision: RoutingDecision): string {
@@ -118,6 +121,8 @@ function describeCause(decision: RoutingDecision): string {
       return describeReasoningOverride(tierLabel, overrideFloor);
     case "llm_classifier":
       return classifierModel ? `LLM classifier (${classifierModel})` : "LLM classifier";
+    case "jev_classifier":
+      return "JEV classifier";
     case "literal_keyword_match":
     case "keyword":
       return matchedKeyword ? `Keyword match: "${matchedKeyword}"` : "Keyword match";
@@ -208,6 +213,20 @@ export function RoutingDecisionCard({
         {requestType && <Row label="Request type">{requestType}</Row>}
 
         <Row label="Decided by">{describeCause(decision)}</Row>
+        {decision.classifier_model && <Row label="Classifier model">{decision.classifier_model}</Row>}
+        {decision.classifier_confidence != null && (
+          <Row label="Confidence">{(decision.classifier_confidence * 100).toFixed(1)}%</Row>
+        )}
+        {decision.classifier_probabilities && (
+          <Row label="Probabilities">
+            {Object.entries(decision.classifier_probabilities).map(([name, probability]) => (
+              <div key={name}>
+                {name}: {(probability * 100).toFixed(1)}%
+              </div>
+            ))}
+          </Row>
+        )}
+        {decision.classifier_cost != null && <Row label="Classifier cost">${decision.classifier_cost.toFixed(8)}</Row>}
 
         {score !== undefined && (
           <Row label="Score">
diff --git a/ui/litellm-dashboard/src/lib/autorouter_presets.test.ts b/ui/litellm-dashboard/src/lib/autorouter_presets.test.ts
index fed11454c23..442dd974368 100644
--- a/ui/litellm-dashboard/src/lib/autorouter_presets.test.ts
+++ b/ui/litellm-dashboard/src/lib/autorouter_presets.test.ts
@@ -680,6 +680,32 @@ describe("autorouter_presets", () => {
   });
 
   describe("buildPresetPrefill", () => {
+    it("preserves JEV settings and drops inactive classifier settings when prefilling", () => {
+      const config = {
+        tiers: { SIMPLE: ["fast"], MEDIUM: [], COMPLEX: [], REASONING: [] },
+        classifier_type: "jev" as const,
+        classification_mode: "every_request" as const,
+        session_affinity: false,
+        deployment_affinity: true,
+        modality_routing: false,
+        modality_pin_override: false,
+        jev_classifier_config: { model: "jev-test", timeout_ms: 4000, circuit_breaker_enabled: false },
+        classifier_llm_config: { model: "stale-judge", timeout_ms: 6000 },
+        classifier_context_window_size: 6,
+      };
+      const prefill = buildPresetPrefill(config, groupsOnly(["fast"]));
+      expect(prefill.complexityRouterConfig).toMatchObject({
+        classifier_type: "jev",
+        jev_classifier_config: config.jev_classifier_config,
+        classifier_context_window_size: 6,
+        classifier_llm_config: undefined,
+      });
+      const llmConfig = { ...config, classifier_type: "llm" as const };
+      const llmPrefill = buildPresetPrefill(llmConfig, groupsOnly(["fast"]));
+      expect(llmPrefill.complexityRouterConfig.jev_classifier_config).toBeUndefined();
+      expect(llmPrefill.complexityRouterConfig.classifier_llm_config).toEqual(config.classifier_llm_config);
+    });
+
     it("prefills a real bundled preset's tiers into the config", () => {
       const preset = getPresetByKey("anthropic_family")!;
       const prefill = buildPresetPrefill(
diff --git a/ui/litellm-dashboard/src/lib/autorouter_presets.ts b/ui/litellm-dashboard/src/lib/autorouter_presets.ts
index 02096cada41..728c1e53574 100644
--- a/ui/litellm-dashboard/src/lib/autorouter_presets.ts
+++ b/ui/litellm-dashboard/src/lib/autorouter_presets.ts
@@ -284,10 +284,11 @@ export const buildPresetPrefill = (
       tier_model_params: resolveParamKeys(hydrateTierModelParams(config.tiers, config.tier_model_configs)),
       tier_labels: hydrateTierLabels(config.tier_labels),
       classifier_type: config.classifier_type,
-      classifier_llm_config: config.classifier_llm_config && {
-        ...config.classifier_llm_config,
-        model: resolve(config.classifier_llm_config.model),
-      },
+      jev_classifier_config: config.classifier_type === "jev" ? config.jev_classifier_config : undefined,
+      classifier_llm_config:
+        config.classifier_type !== "jev" && config.classifier_llm_config
+          ? { ...config.classifier_llm_config, model: resolve(config.classifier_llm_config.model) }
+          : undefined,
       classifier_context_window_size: config.classifier_context_window_size,
       classifier_context_budget_chars: config.classifier_context_budget_chars,
       classifier_context_per_turn_chars: config.classifier_context_per_turn_chars,