feat(core): add support for gemma-4-31b-it model and gemma4-31b alias

packages/core/src/config/defaultModelConfigs.ts

@@ -100,6 +100,17 @@ export const DEFAULT_MODEL_CONFIGS: ModelConfigServiceConfig = {
         },
       },
     },
+    'gemma4-31b': {
+      extends: 'base',
+      modelConfig: {
+        model: 'gemma-4-31b-it',
+        generateContentConfig: {
+          temperature: 1,
+          topP: 0.95,
+          topK: 64,
+        },
+      },
+    },
     // Bases for the internal model configs.
     'gemini-2.5-flash-base': {
       extends: 'base',
@@ -318,6 +329,13 @@ export const DEFAULT_MODEL_CONFIGS: ModelConfigServiceConfig = {
       isVisible: true,
       features: { thinking: false, multimodalToolUse: false },
     },
+    'gemma-4-31b-it': {
+      tier: 'pro',
+      family: 'gemma-4',
+      isPreview: false,
+      isVisible: true,
+      features: { thinking: false, multimodalToolUse: false },
+    },
     // Aliases
     auto: {
       tier: 'auto',
@@ -331,6 +349,12 @@ export const DEFAULT_MODEL_CONFIGS: ModelConfigServiceConfig = {
       isVisible: true,
       features: { thinking: false, multimodalToolUse: false },
     },
+    'gemma4-31b': {
+      tier: 'pro',
+      isPreview: false,
+      isVisible: true,
+      features: { thinking: false, multimodalToolUse: false },
+    },
     pro: {
       tier: 'pro',
       isPreview: false,
@@ -443,6 +467,9 @@ export const DEFAULT_MODEL_CONFIGS: ModelConfigServiceConfig = {
     gemma4: {
       default: 'gemma-4-26b-a4b-it',
     },
+    'gemma4-31b': {
+      default: 'gemma-4-31b-it',
+    },
   },
   classifierIdResolutions: {
     flash: {

packages/core/src/config/models.test.ts

@@ -16,6 +16,7 @@ import {
   getDisplayString,
   DEFAULT_GEMINI_MODEL,
   DEFAULT_GEMMA_4_MODEL,
+  DEFAULT_GEMMA_4_31B_MODEL,
   PREVIEW_GEMINI_MODEL,
   DEFAULT_GEMINI_FLASH_MODEL,
   DEFAULT_GEMINI_FLASH_LITE_MODEL,
@@ -23,6 +24,7 @@ import {
   GEMINI_MODEL_ALIAS_PRO,
   GEMINI_MODEL_ALIAS_FLASH,
   GEMMA_MODEL_ALIAS_4,
+  GEMMA_MODEL_ALIAS_4_31B,
   GEMINI_MODEL_ALIAS_AUTO,
   PREVIEW_GEMINI_FLASH_MODEL,
   PREVIEW_GEMINI_MODEL_AUTO,
@@ -342,6 +344,10 @@ describe('getDisplayString', () => {
     expect(getDisplayString(DEFAULT_GEMMA_4_MODEL)).toBe('Gemma 4 (26B)');
   });
 
+  it('should return the correct display string for Gemma 4 31B', () => {
+    expect(getDisplayString(DEFAULT_GEMMA_4_31B_MODEL)).toBe('Gemma 4 (31B)');
+  });
+
   it('should return the model name as is for other models', () => {
     expect(getDisplayString('custom-model')).toBe('custom-model');
     expect(getDisplayString(DEFAULT_GEMINI_FLASH_LITE_MODEL)).toBe(
@@ -403,6 +409,11 @@ describe('resolveModel', () => {
       expect(model).toBe(DEFAULT_GEMMA_4_MODEL);
     });
 
+    it('should return Gemma 4 31B when gemma4-31b alias is requested', () => {
+      const model = resolveModel(GEMMA_MODEL_ALIAS_4_31B);
+      expect(model).toBe(DEFAULT_GEMMA_4_31B_MODEL);
+    });
+
     it('should return a custom model name when requested', () => {
       const customModel = 'custom-model-v1';
       const model = resolveModel(customModel);
@@ -549,6 +560,7 @@ describe('isActiveModel', () => {
     expect(isActiveModel(DEFAULT_GEMINI_FLASH_MODEL)).toBe(true);
     expect(isActiveModel(PREVIEW_GEMINI_3_1_FLASH_LITE_MODEL)).toBe(true);
     expect(isActiveModel(DEFAULT_GEMMA_4_MODEL)).toBe(true);
+    expect(isActiveModel(DEFAULT_GEMMA_4_31B_MODEL)).toBe(true);
   });
 
   it('should return false for unknown models and aliases', () => {

packages/core/src/config/models.ts

@@ -60,6 +60,7 @@ export const DEFAULT_GEMINI_MODEL = 'gemini-2.5-pro';
 export const DEFAULT_GEMINI_FLASH_MODEL = 'gemini-2.5-flash';
 export const DEFAULT_GEMINI_FLASH_LITE_MODEL = 'gemini-2.5-flash-lite';
 export const DEFAULT_GEMMA_4_MODEL = 'gemma-4-26b-a4b-it';
+export const DEFAULT_GEMMA_4_31B_MODEL = 'gemma-4-31b-it';
 
 export const VALID_GEMINI_MODELS = new Set([
   PREVIEW_GEMINI_MODEL,
@@ -71,6 +72,7 @@ export const VALID_GEMINI_MODELS = new Set([
   DEFAULT_GEMINI_FLASH_MODEL,
   DEFAULT_GEMINI_FLASH_LITE_MODEL,
   DEFAULT_GEMMA_4_MODEL,
+  DEFAULT_GEMMA_4_31B_MODEL,
 ]);
 
 export const PREVIEW_GEMINI_MODEL_AUTO = 'auto-gemini-3';
@@ -82,6 +84,7 @@ export const GEMINI_MODEL_ALIAS_PRO = 'pro';
 export const GEMINI_MODEL_ALIAS_FLASH = 'flash';
 export const GEMINI_MODEL_ALIAS_FLASH_LITE = 'flash-lite';
 export const GEMMA_MODEL_ALIAS_4 = 'gemma4';
+export const GEMMA_MODEL_ALIAS_4_31B = 'gemma4-31b';
 
 export const DEFAULT_GEMINI_EMBEDDING_MODEL = 'gemini-embedding-001';
 
@@ -143,6 +146,10 @@ export function resolveModel(
       resolved = DEFAULT_GEMMA_4_MODEL;
       break;
     }
+    case GEMMA_MODEL_ALIAS_4_31B: {
+      resolved = DEFAULT_GEMMA_4_31B_MODEL;
+      break;
+    }
     default: {
       resolved = requestedModel;
       break;
@@ -245,6 +252,8 @@ export function getDisplayString(
       return PREVIEW_GEMINI_3_1_MODEL;
     case DEFAULT_GEMMA_4_MODEL:
       return 'Gemma 4 (26B)';
+    case DEFAULT_GEMMA_4_31B_MODEL:
+      return 'Gemma 4 (31B)';
     default:
       return model;
   }

packages/core/src/services/test-data/resolved-aliases-retry.golden.json

@@ -105,6 +105,14 @@
       "topK": 64
     }
   },
+  "gemma4-31b": {
+    "model": "gemma-4-31b-it",
+    "generateContentConfig": {
+      "temperature": 1,
+      "topP": 0.95,
+      "topK": 64
+    }
+  },
   "gemini-2.5-flash-base": {
     "model": "gemini-2.5-flash",
     "generateContentConfig": {

packages/core/src/services/test-data/resolved-aliases.golden.json

@@ -105,6 +105,14 @@
       "topK": 64
     }
   },
+  "gemma4-31b": {
+    "model": "gemma-4-31b-it",
+    "generateContentConfig": {
+      "temperature": 1,
+      "topP": 0.95,
+      "topK": 64
+    }
+  },
   "gemini-2.5-flash-base": {
     "model": "gemini-2.5-flash",
     "generateContentConfig": {