Correctly output thinking for Gemini Text adapter

.changeset/flat-buttons-shave.md

@@ -0,0 +1,5 @@
+---
+'@tanstack/ai-gemini': patch
+---
+
+Fix thinking output for Gemini Text adapter

.changeset/goofy-cities-push.md

@@ -0,0 +1,6 @@
+---
+'@tanstack/ai-gemini': patch
+'@tanstack/ai': patch
+---
+
+fixed an issue with gemini and thought chunks processing

examples/ts-react-chat/src/lib/model-selection.ts

@@ -37,8 +37,8 @@ export const MODEL_OPTIONS: Array<ModelOption> = [
   },
   {
     provider: 'gemini',
-    model: 'gemini-exp-1206',
-    label: 'Gemini - Exp 1206 (Pro)',
+    model: 'gemini-2.5-flash',
+    label: 'Gemini 2.5 - Flash',
   },
 
   // Ollama

examples/ts-react-chat/src/routes/api.tanchat.ts

@@ -90,10 +90,17 @@ export const Route = createFileRoute('/api/tanchat')({
               adapter: geminiText(
                 (model || 'gemini-2.5-flash') as 'gemini-2.5-flash',
               ),
+              modelOptions: {
+                thinkingConfig: {
+                  includeThoughts: true,
+                  thinkingBudget: 100,
+                },
+              },
             }),
           grok: () =>
             createChatOptions({
               adapter: grokText((model || 'grok-3') as 'grok-3'),
+              modelOptions: {},
             }),
           ollama: () =>
             createChatOptions({

packages/typescript/ai-gemini/src/adapters/text.ts

@@ -20,6 +20,7 @@ import type {
   GenerateContentResponse,
   GoogleGenAI,
   Part,
+  ThinkingLevel,
 } from '@google/genai'
 import type {
   ContentPart,
@@ -212,15 +213,26 @@ export class GeminiTextAdapter<
 
         for (const part of parts) {
           if (part.text) {
-            accumulatedContent += part.text
-            yield {
-              type: 'content',
-              id: generateId(this.name),
-              model,
-              timestamp,
-              delta: part.text,
-              content: accumulatedContent,
-              role: 'assistant',
+            if (part.thought) {
+              yield {
+                type: 'thinking',
+                content: part.text,
+                delta: part.text,
+                id: generateId(this.name),
+                model,
+                timestamp,
+              }
+            } else {
+              accumulatedContent += part.text
+              yield {
+                type: 'content',
+                id: generateId(this.name),
+                model,
+                timestamp,
+                delta: part.text,
+                content: accumulatedContent,
+                role: 'assistant',
+              }
             }
           }
 
@@ -476,19 +488,29 @@ export class GeminiTextAdapter<
     })
   }
 
-  private mapCommonOptionsToGemini(options: TextOptions) {
-    const providerOpts = options.modelOptions
+  private mapCommonOptionsToGemini(
+    options: TextOptions<GeminiTextProviderOptions>,
+  ) {
+    const modelOpts = options.modelOptions
+    const thinkingConfig = modelOpts?.thinkingConfig
     const requestOptions: GenerateContentParameters = {
       model: options.model,
       contents: this.formatMessages(options.messages),
       config: {
-        ...providerOpts,
+        ...modelOpts,
         temperature: options.temperature,
         topP: options.topP,
         maxOutputTokens: options.maxTokens,
+        thinkingConfig: thinkingConfig
+          ? {
+              ...thinkingConfig,
+              thinkingLevel: thinkingConfig.thinkingLevel
+                ? // Enum is provided by the SDK, we use it for the type but cast it to string constants, here we just cast them back
+                  (thinkingConfig.thinkingLevel as ThinkingLevel)
+                : undefined,
+            }
+          : undefined,
         systemInstruction: options.systemPrompts?.join('\n'),
-        ...((providerOpts as Record<string, unknown> | undefined)
-          ?.generationConfig as Record<string, unknown> | undefined),
         tools: convertToolsToProviderFormat(options.tools),
       },
     }

packages/typescript/ai-gemini/src/model-meta.ts

@@ -1,8 +1,9 @@
 import type {
   GeminiCachedContentOptions,
-  GeminiGenerationConfigOptions,
+  GeminiCommonConfigOptions,
   GeminiSafetyOptions,
   GeminiStructuredOutputOptions,
+  GeminiThinkingAdvancedOptions,
   GeminiThinkingOptions,
   GeminiToolConfigOptions,
 } from './text/text-provider-options'
@@ -77,10 +78,11 @@ const GEMINI_3_PRO = {
 } as const satisfies ModelMeta<
   GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions &
     GeminiStructuredOutputOptions &
-    GeminiThinkingOptions
+    GeminiThinkingOptions &
+    GeminiThinkingAdvancedOptions
 >
 
 const GEMINI_3_FLASH = {
@@ -114,10 +116,11 @@ const GEMINI_3_FLASH = {
 } as const satisfies ModelMeta<
   GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions &
     GeminiStructuredOutputOptions &
-    GeminiThinkingOptions
+    GeminiThinkingOptions &
+    GeminiThinkingAdvancedOptions
 >
 
 const GEMINI_3_PRO_IMAGE = {
@@ -147,10 +150,11 @@ const GEMINI_3_PRO_IMAGE = {
 } as const satisfies ModelMeta<
   GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions &
     GeminiStructuredOutputOptions &
-    GeminiThinkingOptions
+    GeminiThinkingOptions &
+    GeminiThinkingAdvancedOptions
 >
 
 const GEMINI_2_5_PRO = {
@@ -185,7 +189,7 @@ const GEMINI_2_5_PRO = {
 } as const satisfies ModelMeta<
   GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions &
     GeminiStructuredOutputOptions &
     GeminiThinkingOptions
@@ -212,7 +216,7 @@ const GEMINI_2_5_PRO_TTS = {
 } as const satisfies ModelMeta<
   GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions
 >
 
@@ -248,7 +252,7 @@ const GEMINI_2_5_FLASH = {
 } as const satisfies ModelMeta<
   GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions &
     GeminiStructuredOutputOptions &
     GeminiThinkingOptions
@@ -285,7 +289,7 @@ const GEMINI_2_5_FLASH_PREVIEW = {
 } as const satisfies ModelMeta<
   GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions &
     GeminiStructuredOutputOptions &
     GeminiThinkingOptions
@@ -318,7 +322,7 @@ const GEMINI_2_5_FLASH_IMAGE = {
 } as const satisfies ModelMeta<
   GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions
 >
 /**
@@ -377,7 +381,7 @@ const GEMINI_2_5_FLASH_TTS = {
 } as const satisfies ModelMeta<
   GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions
 >
 
@@ -412,7 +416,7 @@ const GEMINI_2_5_FLASH_LITE = {
 } as const satisfies ModelMeta<
   GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions &
     GeminiStructuredOutputOptions &
     GeminiThinkingOptions
@@ -448,7 +452,7 @@ const GEMINI_2_5_FLASH_LITE_PREVIEW = {
 } as const satisfies ModelMeta<
   GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions &
     GeminiStructuredOutputOptions &
     GeminiThinkingOptions
@@ -484,7 +488,7 @@ const GEMINI_2_FLASH = {
 } as const satisfies ModelMeta<
   GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions &
     GeminiStructuredOutputOptions
 >
@@ -515,7 +519,7 @@ const GEMINI_2_FLASH_IMAGE = {
 } as const satisfies ModelMeta<
   GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions
 >
 /* 
@@ -579,7 +583,7 @@ const GEMINI_2_FLASH_LITE = {
 } as const satisfies ModelMeta<
   GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions &
     GeminiStructuredOutputOptions
 >
@@ -603,7 +607,7 @@ const IMAGEN_4_GENERATE = {
 } as const satisfies ModelMeta<
   GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions
 >
 
@@ -626,7 +630,7 @@ const IMAGEN_4_GENERATE_ULTRA = {
 } as const satisfies ModelMeta<
   GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions
 >
 
@@ -649,7 +653,7 @@ const IMAGEN_4_GENERATE_FAST = {
 } as const satisfies ModelMeta<
   GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions
 >
 
@@ -671,7 +675,7 @@ const IMAGEN_3 = {
 } as const satisfies ModelMeta<
   GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions
 >
 /** 
@@ -909,55 +913,57 @@ export type GeminiChatModelProviderOptionsByName = {
   // Models with thinking and structured output support
   [GEMINI_3_PRO.name]: GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions &
     GeminiStructuredOutputOptions &
-    GeminiThinkingOptions
+    GeminiThinkingOptions &
+    GeminiThinkingAdvancedOptions
   [GEMINI_3_FLASH.name]: GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions &
     GeminiStructuredOutputOptions &
-    GeminiThinkingOptions
+    GeminiThinkingOptions &
+    GeminiThinkingAdvancedOptions
   [GEMINI_2_5_PRO.name]: GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions &
     GeminiStructuredOutputOptions &
     GeminiThinkingOptions
   [GEMINI_2_5_FLASH.name]: GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions &
     GeminiStructuredOutputOptions &
     GeminiThinkingOptions
   [GEMINI_2_5_FLASH_PREVIEW.name]: GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions &
     GeminiStructuredOutputOptions &
     GeminiThinkingOptions
   [GEMINI_2_5_FLASH_LITE.name]: GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions &
     GeminiStructuredOutputOptions &
     GeminiThinkingOptions
   [GEMINI_2_5_FLASH_LITE_PREVIEW.name]: GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions &
     GeminiStructuredOutputOptions &
     GeminiThinkingOptions
   // Models with structured output but no thinking support
   [GEMINI_2_FLASH.name]: GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions &
     GeminiStructuredOutputOptions
   [GEMINI_2_FLASH_LITE.name]: GeminiToolConfigOptions &
     GeminiSafetyOptions &
-    GeminiGenerationConfigOptions &
+    GeminiCommonConfigOptions &
     GeminiCachedContentOptions &
     GeminiStructuredOutputOptions
 }