feat(ui): add 1M context auto-router preset (#39490)

* feat(ui): add 1M context auto-router preset

* feat(ui): use heuristic v2 for 1M preset

* fix(ui): keep 1M preset test within lint budget

litellm/proxy/public_endpoints/autorouter_presets.json

@@ -1,4 +1,26 @@
 {
+  "1m_context": {
+    "label": "1M Context",
+    "description": "Routes across models with 1M-token context windows: Luna for simple queries, Terra for medium, Opus 5 for complex, Opus 5 at high thinking for reasoning.",
+    "complexity_router_config": {
+      "tiers": {
+        "SIMPLE": ["gpt-5.6-luna"],
+        "MEDIUM": ["gpt-5.6-terra"],
+        "COMPLEX": ["claude-opus-5"],
+        "REASONING": ["claude-opus-5"]
+      },
+      "tier_model_configs": {
+        "REASONING": [{ "model_name": "claude-opus-5", "litellm_params": { "reasoning_effort": "high" } }]
+      },
+      "classifier_type": "heuristic_v2",
+      "escalation_keywords": ["LITELLM ESCALATE"],
+      "classification_mode": "every_request",
+      "session_affinity": false,
+      "modality_routing": false,
+      "modality_pin_override": false,
+      "deployment_affinity": true
+    }
+  },
   "anthropic_family": {
     "label": "Anthropic Family",
     "description": "Routes across the Claude model family: Haiku for simple queries, Sonnet for medium, Opus for complex, Opus at high thinking for reasoning.",

tests/test_litellm/proxy/public_endpoints/test_public_endpoints.py

@@ -1104,6 +1104,16 @@ def test_get_autorouter_presets_local_mode_serves_bundled_catalog(
     assert response.status_code == 200
     payload = response.json()
     assert "anthropic_family" in payload
+    assert payload["1m_context"]["complexity_router_config"]["classifier_type"] == "heuristic_v2"
+    assert payload["1m_context"]["complexity_router_config"]["tiers"] == {
+        "SIMPLE": ["gpt-5.6-luna"],
+        "MEDIUM": ["gpt-5.6-terra"],
+        "COMPLEX": ["claude-opus-5"],
+        "REASONING": ["claude-opus-5"],
+    }
+    assert payload["1m_context"]["complexity_router_config"]["tier_model_configs"] == {
+        "REASONING": [{"model_name": "claude-opus-5", "litellm_params": {"reasoning_effort": "high"}}]
+    }
     for preset in payload.values():
         assert isinstance(preset["label"], str)
         assert isinstance(preset["description"], str)

ui/litellm-dashboard/src/components/add_model/add_auto_router_tab.test.tsx

@@ -636,7 +636,14 @@ describe("AddAutoRouterTab", () => {
 
     const labels = visibleOptions().map((option) => option.querySelector(".font-medium")?.textContent);
 
-    expect(labels).toEqual(["Anthropic Family", "Gemini Family", "Lite", "OpenAI Family", "Custom Configuration"]);
+    expect(labels).toEqual([
+      "1M Context",
+      "Anthropic Family",
+      "Gemini Family",
+      "Lite",
+      "OpenAI Family",
+      "Custom Configuration",
+    ]);
   });
 
   describe("routing test", () => {
@@ -1060,7 +1067,14 @@ describe("AddAutoRouterTab", () => {
         expect(isOptionDisabled(optionByLabel("Anthropic Family")!)).toBe(false);
       });
       const labels = visibleOptions().map((option) => option.querySelector(".font-medium")?.textContent);
-      expect(labels).toEqual(["Anthropic Family", "Gemini Family", "Lite", "OpenAI Family", "Custom Configuration"]);
+      expect(labels).toEqual([
+        "Anthropic Family",
+        "1M Context",
+        "Gemini Family",
+        "Lite",
+        "OpenAI Family",
+        "Custom Configuration",
+      ]);
     });
 
     it.each([

ui/litellm-dashboard/src/lib/autorouter_presets.test.ts

@@ -28,7 +28,13 @@ const getPresetByKey = (key: string): AutoRouterPreset | undefined => PRESETS.fi
 describe("autorouter_presets", () => {
   it("hydrates exactly the bundled presets", () => {
     const presets = getAllPresets();
-    expect(presets.map((p) => p.label).sort()).toEqual(["Anthropic Family", "Gemini Family", "Lite", "OpenAI Family"]);
+    expect(presets.map((p) => p.label).sort()).toEqual([
+      "1M Context",
+      "Anthropic Family",
+      "Gemini Family",
+      "Lite",
+      "OpenAI Family",
+    ]);
     // Every preset carries all four fields the UI relies on; a JSON typo dropping one fails here.
     for (const p of presets) {
       expect(p).toMatchObject({ key: expect.any(String), label: expect.any(String), description: expect.any(String) });
@@ -202,6 +208,25 @@ describe("autorouter_presets", () => {
     });
   });
 
+  it("pins the 1M context preset to Luna, Terra, and Opus at high thinking", () => {
+    const preset = getPresetByKey("1m_context")!;
+    const expectedTiers = {
+      SIMPLE: ["gpt-5.6-luna"],
+      MEDIUM: ["gpt-5.6-terra"],
+      COMPLEX: ["claude-opus-5"],
+      REASONING: ["claude-opus-5"],
+    };
+    expect(preset.complexity_router_config.classifier_type).toBe("heuristic_v2");
+    expect(preset.complexity_router_config.tiers).toEqual(expectedTiers);
+    expect(preset.complexity_router_config.tier_model_configs).toEqual({
+      REASONING: [{ model_name: "claude-opus-5", litellm_params: { reasoning_effort: "high" } }],
+    });
+    const prefill = buildPresetPrefill(preset.complexity_router_config, groupsOnly(getRequiredModelsInPreset(preset)));
+    expect(prefill.complexityRouterConfig.tier_model_params).toEqual({
+      REASONING: { "claude-opus-5": { reasoning_effort: "high" } },
+    });
+  });
+
   it("pins the gemini preset to concrete model ids, never Google's hot-swapping -latest aliases", () => {
     const gemini = getPresetByKey("gemini_family")!;
     const config = gemini.complexity_router_config;