feat(core): Incorporate Gemini 3 into model config hierarchy. (#13447)

packages/core/src/config/defaultModelConfigs.ts

@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+import { ThinkingLevel } from '@google/genai';
 import type { ModelConfigServiceConfig } from '../services/modelConfigService.js';
 import { DEFAULT_THINKING_MODE } from './models.js';
 
@@ -26,9 +27,6 @@ export const DEFAULT_MODEL_CONFIGS: ModelConfigServiceConfig = {
         generateContentConfig: {
           thinkingConfig: {
             includeThoughts: true,
-            // TODO(joshualitt): Introduce new bases for Gemini 3 models to use
-            // thinkingLevel instead.
-            thinkingBudget: DEFAULT_THINKING_MODE,
           },
           temperature: 1,
           topP: 0.95,
@@ -36,31 +34,51 @@ export const DEFAULT_MODEL_CONFIGS: ModelConfigServiceConfig = {
         },
       },
     },
+    'chat-base-2.5': {
+      extends: 'chat-base',
+      modelConfig: {
+        generateContentConfig: {
+          thinkingConfig: {
+            thinkingBudget: DEFAULT_THINKING_MODE,
+          },
+        },
+      },
+    },
+    'chat-base-3': {
+      extends: 'chat-base',
+      modelConfig: {
+        generateContentConfig: {
+          thinkingConfig: {
+            thinkingLevel: ThinkingLevel.HIGH,
+          },
+        },
+      },
+    },
     // Because `gemini-2.5-pro` and related model configs are "user-facing"
     // today, i.e. they could be passed via `--model`, we have to be careful to
     // ensure these model configs can be used interactively.
     // TODO(joshualitt): Introduce internal base configs for the various models,
     // note: we will have to think carefully about names.
     'gemini-3-pro-preview': {
-      extends: 'chat-base',
+      extends: 'chat-base-3',
       modelConfig: {
         model: 'gemini-3-pro-preview',
       },
     },
     'gemini-2.5-pro': {
-      extends: 'chat-base',
+      extends: 'chat-base-2.5',
       modelConfig: {
         model: 'gemini-2.5-pro',
       },
     },
     'gemini-2.5-flash': {
-      extends: 'chat-base',
+      extends: 'chat-base-2.5',
       modelConfig: {
         model: 'gemini-2.5-flash',
       },
     },
     'gemini-2.5-flash-lite': {
-      extends: 'chat-base',
+      extends: 'chat-base-2.5',
       modelConfig: {
         model: 'gemini-2.5-flash-lite',
       },

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

@@ -6,6 +6,16 @@
     }
   },
   "chat-base": {
+    "generateContentConfig": {
+      "temperature": 1,
+      "topP": 0.95,
+      "thinkingConfig": {
+        "includeThoughts": true
+      },
+      "topK": 64
+    }
+  },
+  "chat-base-2.5": {
     "generateContentConfig": {
       "temperature": 1,
       "topP": 0.95,
@@ -16,6 +26,17 @@
       "topK": 64
     }
   },
+  "chat-base-3": {
+    "generateContentConfig": {
+      "temperature": 1,
+      "topP": 0.95,
+      "thinkingConfig": {
+        "includeThoughts": true,
+        "thinkingLevel": "HIGH"
+      },
+      "topK": 64
+    }
+  },
   "gemini-3-pro-preview": {
     "model": "gemini-3-pro-preview",
     "generateContentConfig": {
@@ -23,7 +44,7 @@
       "topP": 0.95,
       "thinkingConfig": {
         "includeThoughts": true,
-        "thinkingBudget": 8192
+        "thinkingLevel": "HIGH"
       },
       "topK": 64
     }