diff --git a/src/lib/antigravity/ClaudeRequestMapper.ts b/src/lib/antigravity/ClaudeRequestMapper.ts
index 23a1bee..880240b 100644
--- a/src/lib/antigravity/ClaudeRequestMapper.ts
+++ b/src/lib/antigravity/ClaudeRequestMapper.ts
@@ -1,6 +1,8 @@
 import { v4 as uuidv4 } from 'uuid';
-import { mapClaudeModelToGemini } from './ModelMapping';
-import { cleanJsonSchema } from './JsonSchemaUtils';
+import { isPlainObject, isString } from 'lodash-es';
+import { mapClaudeModelToGemini, normalizeGeminiModelAlias } from './ModelMapping';
+import { getMaxOutputTokens, getThinkingBudget } from './ModelSpecs';
+import { cleanJsonSchema, normalizeObjectJsonSchema } from './JsonSchemaUtils';
 import { SignatureStore } from './SignatureStore';
 import { logger } from '../../utils/logger';
 import {
@@ -15,6 +17,11 @@ import {
   FunctionDeclaration,
   SafetySetting,
 } from './types';
+import {
+  buildUserAgent,
+  FALLBACK_VERSION,
+  resolveLocalInstalledVersion,
+} from '@/server/modules/proxy/request-user-agent';
 
 /**
  * Request Configuration
@@ -44,6 +51,7 @@ interface RequestConfig {
 export function transformClaudeRequestIn(
   claudeReq: ClaudeRequest,
   projectId?: string,
+  userAgent?: string,
 ): GeminiInternalRequest {
   // Check for networking tools (server tool or built-in tool)
   const hasWebSearchTool = detectsNetworkingTool(claudeReq.tools);
@@ -55,9 +63,7 @@ export function transformClaudeRequestIn(
   const systemInstruction = buildSystemInstruction(claudeReq.system);
 
   // Map model name
-  const mappedModel = hasWebSearchTool
-    ? 'gemini-2.5-flash'
-    : mapClaudeModelToGemini(claudeReq.model);
+  const mappedModel = hasWebSearchTool ? 'gemini-3-flash' : mapClaudeModelToGemini(claudeReq.model);
 
   // Convert Claude tools to Tool array for networking detection
   const toolsVal: Tool[] | undefined = claudeReq.tools
@@ -70,7 +76,11 @@ export function transformClaudeRequestIn(
   const allowDummyThought = config.finalModel.startsWith('gemini-');
 
   // 4. Generation Config & Thinking
-  let isThinkingEnabled = claudeReq.thinking?.type === 'enabled';
+  const thinkingType = (claudeReq.thinking?.type ?? '').toLowerCase();
+  const autoThinkingEnabled =
+    !claudeReq.thinking && shouldEnableThinkingByDefault(config.finalModel, claudeReq.model);
+  let isThinkingEnabled =
+    thinkingType === 'enabled' || thinkingType === 'adaptive' || autoThinkingEnabled;
 
   if (isThinkingEnabled) {
     const globalSig = SignatureStore.get();
@@ -82,11 +92,18 @@ export function transformClaudeRequestIn(
     });
 
     if (hasFunctionCalls && !hasValidSignatureForFunctionCalls(claudeReq.messages, globalSig)) {
-      isThinkingEnabled = false;
+      if (!isGeminiFlashModel(config.finalModel)) {
+        isThinkingEnabled = false;
+      }
     }
   }
 
-  const generationConfig = buildGenerationConfig(claudeReq, hasWebSearchTool, config.finalModel);
+  const generationConfig = buildGenerationConfig(
+    claudeReq,
+    hasWebSearchTool,
+    config.finalModel,
+    isThinkingEnabled,
+  );
   // Update thinking config based on the final decision
   if (!isThinkingEnabled && generationConfig.thinkingConfig) {
     delete generationConfig.thinkingConfig;
@@ -98,10 +115,11 @@ export function transformClaudeRequestIn(
     toolIdToName,
     isThinkingEnabled,
     allowDummyThought,
+    config.finalModel,
   );
 
   // 3. Tools
-  const tools = buildTools(claudeReq.tools, hasWebSearchTool);
+  const tools = buildTools(claudeReq.tools, hasWebSearchTool, config.finalModel);
 
   // 5. Safety Settings
   const safetySettings = [
@@ -142,7 +160,7 @@ export function transformClaudeRequestIn(
 
   // Inject googleSearch tool if needed (and not already done by buildTools)
   if (config.injectGoogleSearch && !hasWebSearchTool) {
-    injectGoogleSearchTool(innerRequest);
+    injectGoogleSearchTool(innerRequest, config.finalModel);
   }
 
   // Inject imageConfig if present (for image generation models)
@@ -165,11 +183,12 @@ export function transformClaudeRequestIn(
 
   const normalizedProjectId = projectId?.trim();
 
+  const discoveryVersion = resolveLocalInstalledVersion() ?? FALLBACK_VERSION;
   const body: GeminiInternalRequest = {
     requestId: requestId,
     request: innerRequest as GeminiInternalRequest['request'],
     model: config.finalModel,
-    userAgent: 'antigravity',
+    userAgent: userAgent?.trim() || buildUserAgent(discoveryVersion),
     requestType: config.requestType,
   };
 
@@ -194,7 +213,7 @@ function resolveRequestConfig(
   tools?: Tool[],
 ): RequestConfig {
   // 1. Image Generation Check
-  if (mappedModel.startsWith('gemini-3-pro-image')) {
+  if (isGeminiImageModel(mappedModel)) {
     const { imageConfig, parsedBaseModel } = parseImageConfig(originalModel);
     return {
       requestType: 'image_gen',
@@ -212,18 +231,11 @@ function resolveRequestConfig(
   const enableNetworking = isOnlineSuffix || hasNetworkingTool;
 
   let finalModel = mappedModel.replace(/-online$/, '');
-
-  if (finalModel === 'gemini-3-pro-preview') {
-    finalModel = 'gemini-3-pro-high';
-  } else if (finalModel === 'gemini-3-pro-image-preview') {
-    finalModel = 'gemini-3-pro-image';
-  } else if (finalModel === 'gemini-3-flash-preview') {
-    finalModel = 'gemini-3-flash';
-  }
+  finalModel = normalizeGeminiModelAlias(finalModel);
 
   if (enableNetworking) {
-    if (finalModel !== 'gemini-2.5-flash') {
-      finalModel = 'gemini-2.5-flash';
+    if (finalModel !== 'gemini-3-flash') {
+      finalModel = 'gemini-3-flash';
     }
   }
 
@@ -260,6 +272,50 @@ function parseImageConfig(modelName: string): {
   return { imageConfig: config, parsedBaseModel: 'gemini-3-pro-image' };
 }
 
+function isGeminiImageModel(modelName: string): boolean {
+  const normalized = modelName.toLowerCase();
+  return (
+    normalized.startsWith('gemini-3-pro-image') || normalized.startsWith('gemini-3.1-pro-image')
+  );
+}
+
+function isGeminiFlashModel(modelName: string): boolean {
+  const normalized = modelName.toLowerCase();
+  return normalized.includes('gemini-3-flash') || normalized.includes('gemini-3.1-flash');
+}
+
+function shouldEnableThinkingByDefault(mappedModel: string, originalModel: string): boolean {
+  const mappedLower = mappedModel.toLowerCase();
+  const originalLower = originalModel.toLowerCase();
+  return (
+    originalLower.includes('claude-opus-4-5') ||
+    originalLower.includes('claude-opus-4-6') ||
+    mappedLower.includes('-thinking') ||
+    mappedLower.includes('gemini-3.1-pro') ||
+    mappedLower.includes('gemini-3-flash') ||
+    mappedLower.includes('gemini-3.1-flash')
+  );
+}
+
+function isClaudeModel(modelName: string): boolean {
+  return modelName.toLowerCase().includes('claude');
+}
+
+function resolveAdaptiveThinkingLevel(claudeReq: ClaudeRequest): 'low' | 'medium' | 'high' {
+  const effort = String(claudeReq.thinking?.effort ?? '').toLowerCase();
+  if (effort === 'low') {
+    return 'low';
+  }
+  if (effort === 'medium') {
+    return 'medium';
+  }
+  return 'high';
+}
+
+function toToolSchema(schema: unknown): Record<string, unknown> {
+  return normalizeObjectJsonSchema(schema);
+}
+
 /**
  * Detects if networking tools are present
  * Checks tool list for web search related tools
@@ -274,20 +330,23 @@ function detectsNetworkingTool(tools?: (Tool | GeminiToolDeclaration)[]): boolea
     'google_search',
     'web_search_20250305',
     'google_search_retrieval',
+    'builtin_web_search',
   ];
 
   for (const tool of tools) {
     // Claude Tool format
-    if ('name' in tool && tool.name && keywords.includes(tool.name)) {
+    const toolName = (tool as { name?: unknown }).name;
+    if (isString(toolName) && keywords.includes(toolName)) {
       return true;
     }
-    if ('type' in tool && tool.type && keywords.includes(tool.type)) {
+    const toolType = (tool as { type?: unknown }).type;
+    if (isString(toolType) && keywords.includes(toolType)) {
       return true;
     }
 
     // OpenAI nested format (runtime check)
     const openaiTool = tool as { function?: { name?: string } };
-    if (openaiTool.function?.name && keywords.includes(openaiTool.function.name)) {
+    if (isString(openaiTool.function?.name) && keywords.includes(openaiTool.function.name)) {
       return true;
     }
 
@@ -315,15 +374,25 @@ function detectsNetworkingTool(tools?: (Tool | GeminiToolDeclaration)[]): boolea
  * Inject Google Search Tool
  * Adds googleSearch tool to the request
  */
-function injectGoogleSearchTool(body: { tools?: GeminiToolDeclaration[] }) {
+function supportsMixedTools(mappedModel?: string): boolean {
+  if (!mappedModel) {
+    return false;
+  }
+  const modelLower = mappedModel.toLowerCase();
+  return modelLower.includes('gemini-3');
+}
+
+function injectGoogleSearchTool(body: { tools?: GeminiToolDeclaration[] }, mappedModel?: string) {
   if (!body.tools) {
     body.tools = [];
   }
   const toolsArr = body.tools;
 
   const hasFunctions = toolsArr.some((t) => t.functionDeclarations);
-  if (hasFunctions) {
-    logger.info('Skipping googleSearch injection due to existing functionDeclarations');
+  if (hasFunctions && !supportsMixedTools(mappedModel)) {
+    logger.info(
+      'Skipping googleSearch injection due to existing functionDeclarations on old model',
+    );
     return;
   }
 
@@ -351,7 +420,7 @@ function buildSystemInstruction(
   let hasIdentityDirective = false;
 
   if (system) {
-    if (typeof system === 'string') {
+    if (isString(system)) {
       if (system.includes(identityMarker)) {
         hasIdentityDirective = true;
       }
@@ -370,7 +439,7 @@ function buildSystemInstruction(
   }
 
   if (system) {
-    if (typeof system === 'string') {
+    if (isString(system)) {
       parts.push({ text: system });
     } else if (Array.isArray(system)) {
       for (const block of system) {
@@ -437,6 +506,7 @@ function buildContents(
   toolIdToName: Map<string, string>,
   isThinkingEnabled: boolean,
   allowDummyThought: boolean,
+  mappedModel: string,
 ): GeminiContent[] {
   const contents: GeminiContent[] = [];
   let lastThoughtSignature: string | null = null;
@@ -480,12 +550,16 @@ function buildContents(
         cleanJsonSchema(part);
         toolIdToName.set(block.id, block.name);
         const finalSig = block.signature || lastThoughtSignature || SignatureStore.get();
-        if (finalSig) part.thoughtSignature = finalSig;
+        if (finalSig) {
+          part.thoughtSignature = finalSig;
+        } else if (isThinkingEnabled && isGeminiFlashModel(mappedModel)) {
+          part.thoughtSignature = 'skip_thought_signature_validator';
+        }
         parts.push(part);
       } else if (block.type === 'tool_result') {
         const funcName = toolIdToName.get(block.tool_use_id) || block.tool_use_id;
         let mergedContent = '';
-        if (typeof block.content === 'string') mergedContent = block.content;
+        if (isString(block.content)) mergedContent = block.content;
         else if (Array.isArray(block.content))
           mergedContent = block.content
             .filter((b: any) => b.type === 'text')
@@ -524,6 +598,7 @@ function buildContents(
 function buildTools(
   tools: Tool[] | undefined,
   hasWebSearch: boolean,
+  mappedModel: string,
 ): GeminiToolDeclaration[] | null {
   if (!tools) {
     return null;
@@ -535,14 +610,15 @@ function buildTools(
     if (
       tool.name === 'web_search' ||
       tool.name === 'google_search' ||
-      tool.type === 'web_search_20250305'
+      tool.name === 'builtin_web_search' ||
+      tool.type === 'web_search_20250305' ||
+      tool.type === 'builtin_web_search'
     ) {
       hasGoogleSearch = true;
       continue;
     }
     if (tool.name) {
-      const inputSchema = tool.input_schema || { type: 'object', properties: {} };
-      cleanJsonSchema(inputSchema);
+      const inputSchema = toToolSchema(tool.input_schema);
       functionDeclarations.push({
         name: tool.name,
         description: tool.description,
@@ -551,15 +627,24 @@ function buildTools(
     }
   }
 
-  const toolObj: GeminiToolDeclaration = {};
+  const toolList: GeminiToolDeclaration[] = [];
   if (functionDeclarations.length > 0) {
-    toolObj.functionDeclarations = functionDeclarations;
+    toolList.push({ functionDeclarations });
+    if (hasGoogleSearch) {
+      if (supportsMixedTools(mappedModel)) {
+        toolList.push({ googleSearch: {} });
+      } else {
+        logger.info(
+          `[Claude-Request] Skipping googleSearch injection for ${mappedModel} due to existing functionDeclarations on old model`,
+        );
+      }
+    }
   } else if (hasGoogleSearch) {
-    toolObj.googleSearch = {};
+    toolList.push({ googleSearch: {} });
   }
 
-  if (Object.keys(toolObj).length > 0) {
-    return [toolObj];
+  if (toolList.length > 0) {
+    return toolList;
   }
   return null;
 }
@@ -572,32 +657,53 @@ function buildGenerationConfig(
   claudeReq: ClaudeRequest,
   hasWebSearch: boolean,
   mappedModel: string,
+  isThinkingEnabled: boolean,
 ): GenerationConfig {
   const source = String(claudeReq.metadata?.source || '').toLowerCase();
   const isOpenAIPath = source === 'openai';
   const config: GenerationConfig = {};
+  const thinkingType = String(claudeReq.thinking?.type ?? '').toLowerCase();
+
+  const buildThinkingConfig = (): GenerationConfig['thinkingConfig'] => {
+    const thinkingConfig: GenerationConfig['thinkingConfig'] = { includeThoughts: true };
+    if (thinkingType === 'adaptive') {
+      if (isClaudeModel(mappedModel)) {
+        thinkingConfig.thinkingLevel = resolveAdaptiveThinkingLevel(claudeReq);
+      } else {
+        thinkingConfig.thinkingBudget = 24576;
+      }
+    } else if (claudeReq.thinking?.budget_tokens) {
+      let budget = claudeReq.thinking.budget_tokens;
+      const isFlash = hasWebSearch || isGeminiFlashModel(mappedModel);
+      if (isFlash) {
+        budget = Math.min(budget, 24576);
+      }
+      thinkingConfig.thinkingBudget = budget;
+    } else {
+      thinkingConfig.thinkingBudget = getThinkingBudget(mappedModel);
+    }
+    return thinkingConfig;
+  };
 
   if (isOpenAIPath) {
     config.temperature = claudeReq.temperature ?? 1.0;
     config.topP = claudeReq.top_p ?? 0.95;
     if (claudeReq.max_tokens !== undefined) {
       config.maxOutputTokens = claudeReq.max_tokens;
+    } else {
+      config.maxOutputTokens = getMaxOutputTokens(mappedModel);
     }
     if (claudeReq.stop_sequences && claudeReq.stop_sequences.length > 0) {
       config.stopSequences = claudeReq.stop_sequences;
     }
+    if (isThinkingEnabled) {
+      config.thinkingConfig = buildThinkingConfig();
+    }
     return config;
   }
 
-  if (claudeReq.thinking?.type === 'enabled') {
-    const thinkingConfig: GenerationConfig['thinkingConfig'] = { includeThoughts: true };
-    if (claudeReq.thinking.budget_tokens) {
-      let budget = claudeReq.thinking.budget_tokens;
-      const isFlash = hasWebSearch || mappedModel.includes('gemini-2.5-flash');
-      if (isFlash) budget = Math.min(budget, 24576);
-      thinkingConfig.thinkingBudget = budget;
-    }
-    config.thinkingConfig = thinkingConfig;
+  if (isThinkingEnabled) {
+    config.thinkingConfig = buildThinkingConfig();
   }
   if (claudeReq.temperature !== undefined) {
     config.temperature = claudeReq.temperature;
@@ -623,7 +729,7 @@ function buildGenerationConfig(
 function deepCleanUndefined(obj: unknown): void {
   if (Array.isArray(obj)) {
     obj.forEach(deepCleanUndefined);
-  } else if (obj && typeof obj === 'object') {
+  } else if (isPlainObject(obj)) {
     const record = obj as Record<string, unknown>;
     Object.keys(record).forEach((key) => {
       if (record[key] === undefined) delete record[key];
diff --git a/src/lib/antigravity/ClaudeResponseMapper.ts b/src/lib/antigravity/ClaudeResponseMapper.ts
index 6f1f0d6..bd16192 100644
--- a/src/lib/antigravity/ClaudeResponseMapper.ts
+++ b/src/lib/antigravity/ClaudeResponseMapper.ts
@@ -165,21 +165,21 @@ class NonStreamingProcessor {
     let groundingText = '';
 
     if (grounding.webSearchQueries && grounding.webSearchQueries.length > 0) {
-      groundingText += `\n\n---\n**🔍 已为您搜索：** ${grounding.webSearchQueries.join(', ')}`;
+      groundingText += `\n\n---\n**🔍 Searched for you:** ${grounding.webSearchQueries.join(', ')}`;
     }
 
     if (grounding.groundingChunks) {
       const links: string[] = [];
       grounding.groundingChunks.forEach((chunk, index) => {
         if (chunk.web) {
-          const title = chunk.web.title || '网页来源';
+          const title = chunk.web.title || 'Web source';
           const uri = chunk.web.uri || '#';
           links.push(`[${index + 1}] [${title}](${uri})`);
         }
       });
 
       if (links.length > 0) {
-        groundingText += `\n\n**🌐 来源引文：**\n` + links.join('\n');
+        groundingText += `\n\n**🌐 Citations:**\n` + links.join('\n');
       }
     }
 
diff --git a/src/lib/antigravity/ClaudeStreamingMapper.ts b/src/lib/antigravity/ClaudeStreamingMapper.ts
index ec6b876..f506099 100644
--- a/src/lib/antigravity/ClaudeStreamingMapper.ts
+++ b/src/lib/antigravity/ClaudeStreamingMapper.ts
@@ -173,19 +173,19 @@ export class StreamingState {
     // Process grounding (web search) -> convert to Markdown text block
     let groundingText = '';
     if (this.webSearchQuery) {
-      groundingText += `\n\n---\n**🔍 已为您搜索：** ${this.webSearchQuery}`;
+      groundingText += `\n\n---\n**🔍 Searched for you:** ${this.webSearchQuery}`;
     }
     if (this.groundingChunks && this.groundingChunks.length > 0) {
       const links: string[] = [];
       this.groundingChunks.forEach((chunk, i) => {
         if (chunk.web) {
-          const title = chunk.web.title || '网页来源';
+          const title = chunk.web.title || 'Web source';
           const uri = chunk.web.uri || '#';
           links.push(`[${i + 1}] [${title}](${uri})`);
         }
       });
       if (links.length > 0) {
-        groundingText += `\n\n**🌐 来源引文：**\n` + links.join('\n');
+        groundingText += `\n\n**🌐 Citations:**\n` + links.join('\n');
       }
     }
 
diff --git a/src/lib/antigravity/JsonSchemaUtils.ts b/src/lib/antigravity/JsonSchemaUtils.ts
index b2bb11c..f7c7f0f 100644
--- a/src/lib/antigravity/JsonSchemaUtils.ts
+++ b/src/lib/antigravity/JsonSchemaUtils.ts
@@ -32,13 +32,37 @@ export function cleanJsonSchema(value: any) {
   cleanJsonSchemaRecursive(value);
 }
 
+export function normalizeObjectJsonSchema(schema: unknown): Record<string, unknown> {
+  const fallbackSchema: Record<string, unknown> = { type: 'object', properties: {} };
+  if (!schema || typeof schema !== 'object' || Array.isArray(schema)) {
+    return fallbackSchema;
+  }
+
+  const normalizedSchema = JSON.parse(JSON.stringify(schema)) as Record<string, unknown>;
+  cleanJsonSchema(normalizedSchema);
+
+  if (typeof normalizedSchema.type !== 'string') {
+    normalizedSchema.type = 'object';
+  }
+  if (
+    normalizedSchema.type === 'object' &&
+    (!normalizedSchema.properties ||
+      typeof normalizedSchema.properties !== 'object' ||
+      Array.isArray(normalizedSchema.properties))
+  ) {
+    normalizedSchema.properties = {};
+  }
+
+  return normalizedSchema;
+}
+
 /**
  * Recursively expand $ref
  */
 function flattenRefs(map: any, defs: Record<string, any>) {
   if (!map || typeof map !== 'object') return;
 
-  // 检查并替换 $ref
+  // Check and replace $ref
   if (typeof map['$ref'] === 'string') {
     const refPath = map['$ref'];
     // Parse reference name (e.g. #/$defs/MyType -> MyType)
diff --git a/src/lib/antigravity/ModelMapping.ts b/src/lib/antigravity/ModelMapping.ts
index b8a155e..bd8b341 100644
--- a/src/lib/antigravity/ModelMapping.ts
+++ b/src/lib/antigravity/ModelMapping.ts
@@ -1,23 +1,37 @@
 import { logger } from '../../utils/logger';
 
+const PUBLIC_SUPPORTED_MODELS = [
+  'gemini-3.1-pro-high',
+  'gemini-3.1-pro-low',
+  'gemini-3-flash',
+  'claude-sonnet-4-6-thinking',
+  'claude-opus-4-6-thinking',
+] as const;
+
 const CLAUDE_TO_GEMINI: Record<string, string> = {
   // Directly supported models
-  'claude-opus-4-5-thinking': 'claude-opus-4-5-thinking',
+  'claude-sonnet-4-6-thinking': 'claude-sonnet-4-6-thinking',
   'claude-opus-4-6-thinking': 'claude-opus-4-6-thinking',
-  'claude-sonnet-4-5': 'claude-sonnet-4-5',
-  'claude-sonnet-4-5-thinking': 'claude-sonnet-4-5-thinking',
+  'gemini-3.1-pro-low': 'gemini-3.1-pro-low',
+  'gemini-3.1-pro-high': 'gemini-3.1-pro-high',
+  'gemini-3-flash': 'gemini-3-flash',
 
   // Alias mappings
-  'claude-sonnet-4-5-20250929': 'claude-sonnet-4-5-thinking',
-  'claude-3-5-sonnet-20241022': 'claude-sonnet-4-5',
-  'claude-3-5-sonnet-20240620': 'claude-sonnet-4-5',
-  'claude-opus-4': 'claude-opus-4-5-thinking',
-  'claude-opus-4-5-20251101': 'claude-opus-4-5-thinking',
+  'claude-sonnet-4-6': 'claude-sonnet-4-6-thinking',
+  'claude-sonnet-4-6-20260219': 'claude-sonnet-4-6-thinking',
+  'claude-sonnet-4-5': 'claude-sonnet-4-6-thinking',
+  'claude-sonnet-4-5-thinking': 'claude-sonnet-4-6-thinking',
+  'claude-sonnet-4-5-20250929': 'claude-sonnet-4-6-thinking',
+  'claude-3-5-sonnet-20241022': 'claude-sonnet-4-6-thinking',
+  'claude-3-5-sonnet-20240620': 'claude-sonnet-4-6-thinking',
+  'claude-opus-4': 'claude-opus-4-6-thinking',
+  'claude-opus-4-5-thinking': 'claude-opus-4-6-thinking',
+  'claude-opus-4-5-20251101': 'claude-opus-4-6-thinking',
   'claude-opus-4-6': 'claude-opus-4-6-thinking',
   'claude-opus-4-6-20260201': 'claude-opus-4-6-thinking',
-  'claude-haiku-4': 'claude-sonnet-4-5',
-  'claude-3-haiku-20240307': 'claude-sonnet-4-5',
-  'claude-haiku-4-5-20251001': 'claude-sonnet-4-5',
+  'claude-haiku-4': 'claude-sonnet-4-6-thinking',
+  'claude-3-haiku-20240307': 'claude-sonnet-4-6-thinking',
+  'claude-haiku-4-5-20251001': 'claude-sonnet-4-6-thinking',
 
   // OpenAI Protocol Mapping
   'gpt-4': 'gemini-3-flash',
@@ -42,12 +56,13 @@ const CLAUDE_TO_GEMINI: Record<string, string> = {
 
   // Gemini Protocol Mapping
   'gemini-2.5-flash-lite': 'gemini-3-flash',
-  'gemini-3-pro-low': 'gemini-3-pro-preview',
-  'gemini-3-pro-high': 'gemini-3-pro-preview',
-  'gemini-3-pro-preview': 'gemini-3-pro-preview',
-  'gemini-3-pro': 'gemini-3-pro-preview',
+  'gemini-3.1-pro-preview': 'gemini-3.1-pro-high',
+  'gemini-3.1-pro': 'gemini-3.1-pro-high',
+  'gemini-3.0-pro': 'gemini-3.1-pro-high',
   'gemini-2.5-flash': 'gemini-3-flash',
-  'gemini-3-flash': 'gemini-3-flash',
+  'gemini-2.5-pro': 'gemini-3.1-pro-high',
+  'gemini-2.0-flash': 'gemini-3-flash',
+  'gemini-2.0-flash-online': 'gemini-3-flash',
   'gemini-3-pro-image': 'gemini-3-pro-image',
   'internal-background-task': 'gemini-3-flash',
 };
@@ -55,17 +70,50 @@ const CLAUDE_TO_GEMINI: Record<string, string> = {
 const DYNAMIC_IMAGE_BASE_MODEL = 'gemini-3-pro-image';
 const DYNAMIC_IMAGE_RESOLUTIONS = ['', '-2k', '-4k'];
 const DYNAMIC_IMAGE_RATIOS = ['', '-1x1', '-4x3', '-3x4', '-16x9', '-9x16', '-21x9'];
-const EXTRA_DYNAMIC_MODELS = ['gemini-3-flash', 'gemini-3-pro-high', 'gemini-3-pro-low'];
+const EXTRA_DYNAMIC_MODELS = [
+  'gemini-3-flash',
+  'gemini-3.1-pro-high',
+  'gemini-3.1-pro-low',
+];
+
+const DYNAMIC_MODEL_FORWARDING_RULES = new Map<string, string>();
 
 export const MODEL_LIST_CREATED_AT = 1770652800;
 
 export const MODEL_LIST_OWNER = 'antigravity';
 
+const GEMINI_MODEL_ALIASES: Record<string, string> = {
+  'gemini-3.1-pro': 'gemini-3.1-pro-high',
+  'gemini-3.0-pro': 'gemini-3.1-pro-high',
+  'gemini-3.1-pro-preview': 'gemini-3.1-pro-high',
+  'gemini-3-pro-image-preview': 'gemini-3-pro-image',
+  'gemini-3-flash-preview': 'gemini-3-flash',
+};
+
 export function getSupportedModels(): string[] {
-  return Object.keys(CLAUDE_TO_GEMINI);
+  return [...PUBLIC_SUPPORTED_MODELS];
 }
 
-export function getAllDynamicModels(customMapping: Record<string, string> = {}): string[] {
+export function updateDynamicForwardingRules(oldModel: string, newModel: string): void {
+  const normalizedOld = oldModel.trim();
+  const normalizedNew = newModel.trim();
+  if (!normalizedOld || !normalizedNew) {
+    return;
+  }
+  if (!DYNAMIC_MODEL_FORWARDING_RULES.has(normalizedOld)) {
+    logger.info(`[Router] Registered dynamic forwarding rule: ${normalizedOld} -> ${normalizedNew}`);
+  }
+  DYNAMIC_MODEL_FORWARDING_RULES.set(normalizedOld, normalizedNew);
+}
+
+export function getDynamicForwardingTarget(modelId: string): string | undefined {
+  return DYNAMIC_MODEL_FORWARDING_RULES.get(modelId);
+}
+
+export function getAllDynamicModels(
+  customMapping: Record<string, string> = {},
+  dynamicModelIds?: Iterable<string>,
+): string[] {
   const modelIds = new Set<string>();
 
   for (const modelId of getSupportedModels()) {
@@ -86,7 +134,17 @@ export function getAllDynamicModels(customMapping: Record<string, string> = {}):
     modelIds.add(modelId);
   }
 
-  return [...modelIds].filter((id) => !/gemini-[12](\.|$|-)/.test(id)).sort();
+  if (dynamicModelIds) {
+    for (const dynamicModelId of dynamicModelIds) {
+      if (typeof dynamicModelId === 'string' && dynamicModelId.trim() !== '') {
+        modelIds.add(dynamicModelId.trim());
+      }
+    }
+  }
+
+  return [...modelIds]
+    .filter((id) => !shouldHideDeprecatedModelFromList(id))
+    .sort();
 }
 
 export function mapClaudeModelToGemini(input: string): string {
@@ -98,6 +156,11 @@ export function mapClaudeModelToGemini(input: string): string {
   return input;
 }
 
+export function normalizeGeminiModelAlias(modelId: string): string {
+  const normalizedModelId = modelId.trim().toLowerCase();
+  return GEMINI_MODEL_ALIASES[normalizedModelId] ?? modelId;
+}
+
 /**
  * Core Model Routing Engine
  * Priority: Custom Mapping (Exact) > Group Mapping (Family) > System Mapping (Built-in Plugin)
@@ -108,6 +171,12 @@ export function resolveModelRoute(
   openaiMapping: Record<string, string>,
   anthropicMapping: Record<string, string>,
 ): string {
+  const dynamicForwarded = getDynamicForwardingTarget(originalModel);
+  if (dynamicForwarded) {
+    logger.info(`[Router] Dynamic deprecated-model forwarding: ${originalModel} -> ${dynamicForwarded}`);
+    return dynamicForwarded;
+  }
+
   // 1. Check custom exact mapping (Highest priority)
   if (customMapping[originalModel]) {
     logger.info(
@@ -194,3 +263,31 @@ export function resolveModelRoute(
   // 4. Fall through to system default mapping logic
   return mapClaudeModelToGemini(originalModel);
 }
+
+function shouldHideDeprecatedModelFromList(modelId: string): boolean {
+  const normalized = modelId.toLowerCase();
+
+  if (/^gemini-1(\.|$|-)/.test(normalized) || /^gemini-2(\.|$|-)/.test(normalized)) {
+    return true;
+  }
+
+  if (normalized === 'gemini-3.1-pro' || normalized === 'gemini-3.1-pro-preview') {
+    return true;
+  }
+
+  const isLegacyGeminiPro =
+    /^gemini-3(\.0)?-pro($|-)/.test(normalized) && !normalized.startsWith('gemini-3-pro-image');
+  if (isLegacyGeminiPro) {
+    return true;
+  }
+
+  if (
+    normalized.includes('claude-sonnet-4-5') ||
+    normalized.includes('claude-opus-4-5') ||
+    normalized.includes('claude-haiku-4-5')
+  ) {
+    return true;
+  }
+
+  return false;
+}
diff --git a/src/lib/antigravity/ModelSpecs.ts b/src/lib/antigravity/ModelSpecs.ts
new file mode 100644
index 0000000..5d9523b
--- /dev/null
+++ b/src/lib/antigravity/ModelSpecs.ts
@@ -0,0 +1,40 @@
+import modelSpecsJson from './model-specs';
+
+type ModelSpec = {
+  max_output_tokens?: number;
+  thinking_budget?: number;
+  is_thinking?: boolean;
+};
+
+type SpecsConfig = {
+  models: Record<string, ModelSpec>;
+  aliases: Record<string, string>;
+};
+
+const DEFAULT_MAX_OUTPUT_TOKENS = 65535;
+const DEFAULT_THINKING_BUDGET = 24576;
+
+const SPECS = modelSpecsJson as SpecsConfig;
+
+export function resolveModelAlias(modelId: string): string {
+  const normalized = modelId.trim();
+  return SPECS.aliases[normalized] ?? normalized;
+}
+
+export function getMaxOutputTokens(modelId: string): number {
+  const resolved = resolveModelAlias(modelId);
+  const fromSpec = SPECS.models[resolved]?.max_output_tokens;
+  if (typeof fromSpec === 'number' && Number.isFinite(fromSpec) && fromSpec > 0) {
+    return Math.floor(fromSpec);
+  }
+  return DEFAULT_MAX_OUTPUT_TOKENS;
+}
+
+export function getThinkingBudget(modelId: string): number {
+  const resolved = resolveModelAlias(modelId);
+  const fromSpec = SPECS.models[resolved]?.thinking_budget;
+  if (typeof fromSpec === 'number' && Number.isFinite(fromSpec) && fromSpec >= 0) {
+    return Math.floor(fromSpec);
+  }
+  return DEFAULT_THINKING_BUDGET;
+}
diff --git a/src/lib/antigravity/model-specs.json b/src/lib/antigravity/model-specs.json
new file mode 100644
index 0000000..02dbad3
--- /dev/null
+++ b/src/lib/antigravity/model-specs.json
@@ -0,0 +1,52 @@
+{
+  "models": {
+    "gemini-3-flash": {
+      "max_output_tokens": 65536,
+      "thinking_budget": 32768,
+      "is_thinking": true
+    },
+    "gemini-3.1-pro-low": {
+      "max_output_tokens": 65536,
+      "thinking_budget": 32768,
+      "is_thinking": true
+    },
+    "gemini-3.1-pro-high": {
+      "max_output_tokens": 65536,
+      "thinking_budget": 49152,
+      "is_thinking": true
+    },
+    "gemini-3-pro-image": {
+      "max_output_tokens": 65536,
+      "thinking_budget": 24576,
+      "is_thinking": true
+    },
+    "claude-sonnet-4-6-thinking": {
+      "max_output_tokens": 64000,
+      "thinking_budget": 32768,
+      "is_thinking": true
+    },
+    "claude-opus-4-6-thinking": {
+      "max_output_tokens": 64000,
+      "thinking_budget": 32768,
+      "is_thinking": true
+    },
+    "gpt-oss-120b-medium": {
+      "max_output_tokens": 32768,
+      "thinking_budget": 0,
+      "is_thinking": false
+    }
+  },
+  "aliases": {
+    "gpt-4o": "gemini-3-flash",
+    "gpt-3.5-turbo": "gemini-3-flash",
+    "gemini-2.0-flash": "gemini-3-flash",
+    "gemini-2.5-flash": "gemini-3-flash",
+    "gemini-3.1-pro": "gemini-3.1-pro-high",
+    "gemini-3.1-pro-preview": "gemini-3.1-pro-high",
+    "claude-sonnet-4-6": "claude-sonnet-4-6-thinking",
+    "claude-sonnet-4-5": "claude-sonnet-4-6-thinking",
+    "claude-3-5-sonnet": "claude-sonnet-4-6-thinking",
+    "claude-3-7-sonnet": "claude-sonnet-4-6-thinking",
+    "claude-opus-4-5-thinking": "claude-opus-4-6-thinking"
+  }
+}
diff --git a/src/lib/antigravity/model-specs.ts b/src/lib/antigravity/model-specs.ts
new file mode 100644
index 0000000..7aad13c
--- /dev/null
+++ b/src/lib/antigravity/model-specs.ts
@@ -0,0 +1,54 @@
+const modelSpecs = {
+  models: {
+    'gemini-3-flash': {
+      max_output_tokens: 65536,
+      thinking_budget: 32768,
+      is_thinking: true,
+    },
+    'gemini-3.1-pro-low': {
+      max_output_tokens: 65536,
+      thinking_budget: 32768,
+      is_thinking: true,
+    },
+    'gemini-3.1-pro-high': {
+      max_output_tokens: 65536,
+      thinking_budget: 49152,
+      is_thinking: true,
+    },
+    'gemini-3-pro-image': {
+      max_output_tokens: 65536,
+      thinking_budget: 24576,
+      is_thinking: true,
+    },
+    'claude-sonnet-4-6-thinking': {
+      max_output_tokens: 64000,
+      thinking_budget: 32768,
+      is_thinking: true,
+    },
+    'claude-opus-4-6-thinking': {
+      max_output_tokens: 64000,
+      thinking_budget: 32768,
+      is_thinking: true,
+    },
+    'gpt-oss-120b-medium': {
+      max_output_tokens: 32768,
+      thinking_budget: 0,
+      is_thinking: false,
+    },
+  },
+  aliases: {
+    'gpt-4o': 'gemini-3-flash',
+    'gpt-3.5-turbo': 'gemini-3-flash',
+    'gemini-2.0-flash': 'gemini-3-flash',
+    'gemini-2.5-flash': 'gemini-3-flash',
+    'gemini-3.1-pro': 'gemini-3.1-pro-high',
+    'gemini-3.1-pro-preview': 'gemini-3.1-pro-high',
+    'claude-sonnet-4-6': 'claude-sonnet-4-6-thinking',
+    'claude-sonnet-4-5': 'claude-sonnet-4-6-thinking',
+    'claude-3-5-sonnet': 'claude-sonnet-4-6-thinking',
+    'claude-3-7-sonnet': 'claude-sonnet-4-6-thinking',
+    'claude-opus-4-5-thinking': 'claude-opus-4-6-thinking',
+  },
+} as const;
+
+export default modelSpecs;
diff --git a/src/lib/antigravity/types.ts b/src/lib/antigravity/types.ts
index 0c846e0..de114ae 100644
--- a/src/lib/antigravity/types.ts
+++ b/src/lib/antigravity/types.ts
@@ -64,6 +64,7 @@ export interface ClaudeRequest {
 export interface ThinkingConfig {
   type: 'enabled' | string;
   budget_tokens?: number;
+  effort?: 'low' | 'medium' | 'high' | 'max' | string;
 }
 
 export type SystemPrompt = string | SystemBlock[];
@@ -194,6 +195,8 @@ export interface ThinkingGeminiConfig {
   includeThoughts: boolean;
   /** Thinking token budget */
   thinkingBudget?: number;
+  /** Thinking level for Claude-native adaptive modes */
+  thinkingLevel?: 'low' | 'medium' | 'high' | string;
 }
 
 /**
@@ -306,11 +309,22 @@ export interface QuotaData {
   models: Record<string, ModelQuotaInfo>;
   isForbidden: boolean;
   subscriptionTier?: string;
+  model_forwarding_rules?: Record<string, string>;
+  is_forbidden?: boolean;
+  subscription_tier?: string;
 }
 
 export interface ModelQuotaInfo {
   percentage: number;
   resetTime: string;
+  display_name?: string;
+  supports_images?: boolean;
+  supports_thinking?: boolean;
+  thinking_budget?: number;
+  recommended?: boolean;
+  max_tokens?: number;
+  max_output_tokens?: number;
+  supported_mime_types?: Record<string, boolean>;
 }
 
 export interface LoadProjectResponse {
@@ -327,7 +341,21 @@ export interface Tier {
 }
 
 export interface QuotaApiResponse {
-  models: Record<string, { quotaInfo?: { remainingFraction?: number; resetTime?: string } }>;
+  models: Record<
+    string,
+    {
+      quotaInfo?: { remainingFraction?: number; resetTime?: string };
+      displayName?: string;
+      supportsImages?: boolean;
+      supportsThinking?: boolean;
+      thinkingBudget?: number;
+      recommended?: boolean;
+      maxTokens?: number;
+      maxOutputTokens?: number;
+      supportedMimeTypes?: Record<string, boolean>;
+    }
+  >;
+  deprecatedModelIds?: Record<string, { newModelId?: string }>;
 }
 
 // --- Response Models ---
diff --git a/src/tests/AntigravityCoreFeatures.test.ts b/src/tests/AntigravityCoreFeatures.test.ts
index b364212..a9b8f5d 100644
--- a/src/tests/AntigravityCoreFeatures.test.ts
+++ b/src/tests/AntigravityCoreFeatures.test.ts
@@ -79,7 +79,7 @@ describe('Antigravity Core Features (Business Logic)', () => {
       const requestWithTools = {
         ...BASE_REQUEST,
         // Maps to a gemini-3 model potentially
-        model: 'gemini-3-pro-preview',
+        model: 'gemini-3.1-pro-preview',
         tools: [{ name: 'get_weather' }], // Mock tool structure
         thinking: { type: 'enabled', budget_tokens: 1000 },
       } as any;
@@ -96,7 +96,7 @@ describe('Antigravity Core Features (Business Logic)', () => {
 
       const requestWithTools = {
         ...BASE_REQUEST,
-        model: 'gemini-3-pro-preview',
+        model: 'gemini-3.1-pro-preview',
         tools: [{ name: 'get_weather' }],
         thinking: { type: 'enabled', budget_tokens: 1000 },
       } as any;
@@ -110,7 +110,7 @@ describe('Antigravity Core Features (Business Logic)', () => {
     it('should KEEP thinking mode if NO function calls exist (pure thinking)', () => {
       const requestPureThinking = {
         ...BASE_REQUEST,
-        model: 'gemini-3-pro-preview',
+        model: 'gemini-3.1-pro-preview',
         // No tools
         thinking: { type: 'enabled', budget_tokens: 1000 },
       } as any;
@@ -120,5 +120,60 @@ describe('Antigravity Core Features (Business Logic)', () => {
       // Should keep thinking config
       expect(result.request.generationConfig?.thinkingConfig).toBeDefined();
     });
+
+    it('should auto-enable thinking for gemini-3-flash even without explicit thinking config', () => {
+      const result = transformClaudeRequestIn(
+        {
+          ...BASE_REQUEST,
+          model: 'gemini-3-flash',
+          thinking: undefined,
+        } as any,
+        'test-project',
+      );
+
+      expect(result.request.generationConfig?.thinkingConfig).toBeDefined();
+      expect(result.request.generationConfig?.thinkingConfig?.includeThoughts).toBe(true);
+    });
+
+    it('should inject flash sentinel thoughtSignature for tool_use without cached signature', () => {
+      const requestWithToolUse = {
+        ...BASE_REQUEST,
+        model: 'gemini-3-flash',
+        thinking: undefined,
+        messages: [
+          {
+            role: 'assistant',
+            content: [
+              {
+                type: 'tool_use',
+                id: 'call_1',
+                name: 'get_weather',
+                input: { location: 'Beijing' },
+              },
+            ],
+          },
+        ],
+      } as any;
+
+      const result = transformClaudeRequestIn(requestWithToolUse, 'test-project');
+      const part = result.request.contents?.[0]?.parts?.[0] as any;
+      expect(part?.thoughtSignature).toBe('skip_thought_signature_validator');
+    });
+
+    it('should keep mixed tools for gemini 2.x+ when both function and web search are requested', () => {
+      const mixedToolsRequest = {
+        ...BASE_REQUEST,
+        model: 'gemini-2.0-flash-online',
+        tools: [{ name: 'get_weather' }, { name: 'web_search' }],
+      } as any;
+
+      const result = transformClaudeRequestIn(mixedToolsRequest, 'test-project');
+      const tools = result.request.tools || [];
+      const hasFunctions = tools.some((tool: any) => Array.isArray(tool.functionDeclarations));
+      const hasGoogleSearch = tools.some((tool: any) => tool.googleSearch);
+
+      expect(hasFunctions).toBe(true);
+      expect(hasGoogleSearch).toBe(true);
+    });
   });
 });
diff --git a/src/tests/scripts/project-id-request-validation.ts b/src/tests/scripts/project-id-request-validation.ts
index 491e73d..73ce324 100644
--- a/src/tests/scripts/project-id-request-validation.ts
+++ b/src/tests/scripts/project-id-request-validation.ts
@@ -8,6 +8,8 @@ const mockTokenManager: any = {
   getNextToken: async () => null,
   markAsRateLimited: () => undefined,
   markAsForbidden: () => undefined,
+  markFromUpstreamError: () => undefined,
+  recordParityError: () => undefined,
 };
 
 const mockGeminiClient: any = {
@@ -225,7 +227,11 @@ async function validateRuntimeAnthropicRequestFromRealTokenManager(): Promise<vo
   await realTokenManager.onModuleInit();
 
   const tokenManagerProxy = {
-    getNextToken: async (options?: { sessionKey?: string; excludeAccountIds?: string[] }) => {
+    getNextToken: async (options?: {
+      sessionKey?: string;
+      excludeAccountIds?: string[];
+      model?: string;
+    }) => {
       observedGetNextTokenOptions = options ?? null;
       selectedToken = await realTokenManager.getNextToken(options);
       return selectedToken;
@@ -234,6 +240,14 @@ async function validateRuntimeAnthropicRequestFromRealTokenManager(): Promise<vo
       realTokenManager.markAsRateLimited(accountIdOrEmail),
     markAsForbidden: (accountIdOrEmail: string) =>
       realTokenManager.markAsForbidden(accountIdOrEmail),
+    markFromUpstreamError: (args: {
+      accountIdOrEmail: string;
+      status?: number;
+      retryAfter?: string;
+      body?: string;
+      model?: string;
+    }) => realTokenManager.markFromUpstreamError(args),
+    recordParityError: () => realTokenManager.recordParityError(),
   };
 
   try {