diff --git a/backend/internal/domain/constants.go b/backend/internal/domain/constants.go
index 05b5adc1..5963994e 100644
--- a/backend/internal/domain/constants.go
+++ b/backend/internal/domain/constants.go
@@ -73,6 +73,7 @@ var DefaultAntigravityModelMapping = map[string]string{
 	"claude-opus-4-6-thinking":   "claude-opus-4-6-thinking", // 官方模型
 	"claude-opus-4-6":            "claude-opus-4-6-thinking", // 简称映射
 	"claude-opus-4-5-thinking":   "claude-opus-4-6-thinking", // 迁移旧模型
+	"claude-sonnet-4-6":          "claude-sonnet-4-6",
 	"claude-sonnet-4-5":          "claude-sonnet-4-5",
 	"claude-sonnet-4-5-thinking": "claude-sonnet-4-5-thinking",
 	// Claude 详细版本 ID 映射
diff --git a/backend/internal/pkg/antigravity/request_transformer.go b/backend/internal/pkg/antigravity/request_transformer.go
index 3ba04b95..55cdd786 100644
--- a/backend/internal/pkg/antigravity/request_transformer.go
+++ b/backend/internal/pkg/antigravity/request_transformer.go
@@ -206,6 +206,7 @@ type modelInfo struct {
 var modelInfoMap = map[string]modelInfo{
 	"claude-opus-4-5":   {DisplayName: "Claude Opus 4.5", CanonicalID: "claude-opus-4-5-20250929"},
 	"claude-opus-4-6":   {DisplayName: "Claude Opus 4.6", CanonicalID: "claude-opus-4-6"},
+	"claude-sonnet-4-6": {DisplayName: "Claude Sonnet 4.6", CanonicalID: "claude-sonnet-4-6"},
 	"claude-sonnet-4-5": {DisplayName: "Claude Sonnet 4.5", CanonicalID: "claude-sonnet-4-5-20250929"},
 	"claude-haiku-4-5":  {DisplayName: "Claude Haiku 4.5", CanonicalID: "claude-haiku-4-5-20251001"},
 }
diff --git a/backend/internal/service/antigravity_model_mapping_test.go b/backend/internal/service/antigravity_model_mapping_test.go
index f3621555..71939d26 100644
--- a/backend/internal/service/antigravity_model_mapping_test.go
+++ b/backend/internal/service/antigravity_model_mapping_test.go
@@ -76,6 +76,12 @@ func TestAntigravityGatewayService_GetMappedModel(t *testing.T) {
 		},
 
 		// 3. 默认映射中的透传（映射到自己）
+		{
+			name:           "默认映射透传 - claude-sonnet-4-6",
+			requestedModel: "claude-sonnet-4-6",
+			accountMapping: nil,
+			expected:       "claude-sonnet-4-6",
+		},
 		{
 			name:           "默认映射透传 - claude-sonnet-4-5",
 			requestedModel: "claude-sonnet-4-5",
diff --git a/backend/migrations/056_add_sonnet46_to_model_mapping.sql b/backend/migrations/056_add_sonnet46_to_model_mapping.sql
new file mode 100644
index 00000000..aa7657d7
--- /dev/null
+++ b/backend/migrations/056_add_sonnet46_to_model_mapping.sql
@@ -0,0 +1,42 @@
+-- Add claude-sonnet-4-6 to model_mapping for all Antigravity accounts
+--
+-- Background:
+-- Antigravity now supports claude-sonnet-4-6
+--
+-- Strategy:
+-- Directly overwrite the entire model_mapping with updated mappings
+-- This ensures consistency with DefaultAntigravityModelMapping in constants.go
+
+UPDATE accounts
+SET credentials = jsonb_set(
+    credentials,
+    '{model_mapping}',
+    '{
+        "claude-opus-4-6-thinking": "claude-opus-4-6-thinking",
+        "claude-opus-4-6": "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-sonnet-4-6": "claude-sonnet-4-6",
+        "claude-sonnet-4-5": "claude-sonnet-4-5",
+        "claude-sonnet-4-5-thinking": "claude-sonnet-4-5-thinking",
+        "claude-sonnet-4-5-20250929": "claude-sonnet-4-5",
+        "claude-haiku-4-5": "claude-sonnet-4-5",
+        "claude-haiku-4-5-20251001": "claude-sonnet-4-5",
+        "gemini-2.5-flash": "gemini-2.5-flash",
+        "gemini-2.5-flash-lite": "gemini-2.5-flash-lite",
+        "gemini-2.5-flash-thinking": "gemini-2.5-flash-thinking",
+        "gemini-2.5-pro": "gemini-2.5-pro",
+        "gemini-3-flash": "gemini-3-flash",
+        "gemini-3-pro-high": "gemini-3-pro-high",
+        "gemini-3-pro-low": "gemini-3-pro-low",
+        "gemini-3-pro-image": "gemini-3-pro-image",
+        "gemini-3-flash-preview": "gemini-3-flash",
+        "gemini-3-pro-preview": "gemini-3-pro-high",
+        "gemini-3-pro-image-preview": "gemini-3-pro-image",
+        "gpt-oss-120b-medium": "gpt-oss-120b-medium",
+        "tab_flash_lite_preview": "tab_flash_lite_preview"
+    }'::jsonb
+)
+WHERE platform = 'antigravity'
+  AND deleted_at IS NULL
+  AND credentials->'model_mapping' IS NOT NULL;
diff --git a/frontend/src/composables/useModelWhitelist.ts b/frontend/src/composables/useModelWhitelist.ts
index 98c668f0..b57e6af1 100644
--- a/frontend/src/composables/useModelWhitelist.ts
+++ b/frontend/src/composables/useModelWhitelist.ts
@@ -60,6 +60,7 @@ const antigravityModels = [
   // Claude 4.5+ 系列
   'claude-opus-4-6',
   'claude-opus-4-5-thinking',
+  'claude-sonnet-4-6',
   'claude-sonnet-4-5',
   'claude-sonnet-4-5-thinking',
   // Gemini 2.5 系列
@@ -271,6 +272,7 @@ const antigravityPresetMappings = [
   { label: 'Gemini 3→Flash', from: 'gemini-3*', to: 'gemini-3-flash', color: 'bg-amber-100 text-amber-700 hover:bg-amber-200 dark:bg-amber-900/30 dark:text-amber-400' },
   { label: 'Gemini 2.5→Flash', from: 'gemini-2.5*', to: 'gemini-2.5-flash', color: 'bg-orange-100 text-orange-700 hover:bg-orange-200 dark:bg-orange-900/30 dark:text-orange-400' },
   // 精确映射
+  { label: 'Sonnet 4.6', from: 'claude-sonnet-4-6', to: 'claude-sonnet-4-6', color: 'bg-cyan-100 text-cyan-700 hover:bg-cyan-200 dark:bg-cyan-900/30 dark:text-cyan-400' },
   { label: 'Sonnet 4.5', from: 'claude-sonnet-4-5', to: 'claude-sonnet-4-5', color: 'bg-cyan-100 text-cyan-700 hover:bg-cyan-200 dark:bg-cyan-900/30 dark:text-cyan-400' },
   { label: 'Opus 4.6-thinking', from: 'claude-opus-4-6-thinking', to: 'claude-opus-4-6-thinking', color: 'bg-pink-100 text-pink-700 hover:bg-pink-200 dark:bg-pink-900/30 dark:text-pink-400' }
 ]