fix: normalize antigravity gemini 3.1 pro routing

backend/internal/domain/constants.go

@@ -68,6 +68,9 @@ const (
 	SubscriptionStatusSuspended = "suspended"
 )
 
+// AntigravityGemini31ProAgentModel is the upstream route for Gemini 3.1 Pro High.
+const AntigravityGemini31ProAgentModel = "gemini-pro-agent"
+
 // DefaultAntigravityModelMapping 是 Antigravity 平台的默认模型映射
 // 当账号未配置 model_mapping 时使用此默认值
 // 与前端 useModelWhitelist.ts 中的 antigravityDefaultMappings 保持一致
@@ -103,10 +106,12 @@ var DefaultAntigravityModelMapping = map[string]string{
 	"gemini-3-flash-preview": "gemini-3-flash",
 	"gemini-3-pro-preview":   "gemini-3-pro-high",
 	// Gemini 3.1 白名单
-	"gemini-3.1-pro-high": "gemini-3.1-pro-high",
-	"gemini-3.1-pro-low":  "gemini-3.1-pro-low",
+	AntigravityGemini31ProAgentModel: AntigravityGemini31ProAgentModel,
+	"gemini-3.1-pro":                 AntigravityGemini31ProAgentModel,
+	"gemini-3.1-pro-high":            AntigravityGemini31ProAgentModel,
+	"gemini-3.1-pro-low":             "gemini-3.1-pro-low",
 	// Gemini 3.1 preview 映射
-	"gemini-3.1-pro-preview": "gemini-3.1-pro-high",
+	"gemini-3.1-pro-preview": AntigravityGemini31ProAgentModel,
 	// Gemini 3.1 image 白名单
 	"gemini-3.1-flash-image": "gemini-3.1-flash-image",
 	// Gemini 3.1 image preview 映射

backend/internal/domain/constants_test.go

@@ -43,6 +43,28 @@ func TestDefaultAntigravityModelMapping_ContainsNewClaudeModels(t *testing.T) {
 	}
 }
 
+func TestDefaultAntigravityModelMapping_Gemini31ProAliases(t *testing.T) {
+	t.Parallel()
+
+	cases := map[string]string{
+		AntigravityGemini31ProAgentModel: AntigravityGemini31ProAgentModel,
+		"gemini-3.1-pro":                 AntigravityGemini31ProAgentModel,
+		"gemini-3.1-pro-high":            AntigravityGemini31ProAgentModel,
+		"gemini-3.1-pro-preview":         AntigravityGemini31ProAgentModel,
+		"gemini-3.1-pro-low":             "gemini-3.1-pro-low",
+	}
+
+	for from, want := range cases {
+		got, ok := DefaultAntigravityModelMapping[from]
+		if !ok {
+			t.Fatalf("expected mapping for %q to exist", from)
+		}
+		if got != want {
+			t.Fatalf("unexpected mapping for %q: got %q want %q", from, got, want)
+		}
+	}
+}
+
 func TestDefaultBedrockModelMapping_ContainsNewClaudeModels(t *testing.T) {
 	t.Parallel()
 

backend/internal/service/account.go

@@ -580,6 +580,7 @@ func (a *Account) resolveModelMapping(rawMapping map[string]any) map[string]stri
 				"gemini-3.1-pro-high",
 				"gemini-3.1-pro-low",
 			})
+			applyAntigravityGemini31ProAliases(result)
 		}
 		return result
 	}
@@ -646,6 +647,61 @@ func ensureAntigravityDefaultPassthroughs(mapping map[string]string, models []st
 	}
 }
 
+func applyAntigravityGemini31ProAliases(mapping map[string]string) {
+	target := strings.TrimSpace(mapping[domain.AntigravityGemini31ProAgentModel])
+	if target == "" {
+		return
+	}
+
+	aliases := []struct {
+		model         string
+		legacyTargets map[string]struct{}
+	}{
+		{
+			model: "gemini-3.1-pro",
+			legacyTargets: map[string]struct{}{
+				"gemini-3.1-pro": {},
+			},
+		},
+		{
+			model: "gemini-3.1-pro-high",
+			legacyTargets: map[string]struct{}{
+				"gemini-3.1-pro-high": {},
+			},
+		},
+		{
+			model: "gemini-3.1-pro-preview",
+			legacyTargets: map[string]struct{}{
+				"gemini-3.1-pro-preview": {},
+				"gemini-3.1-pro-high":    {},
+			},
+		},
+	}
+
+	for _, alias := range aliases {
+		current, exists := mapping[alias.model]
+		if exists {
+			if _, legacy := alias.legacyTargets[current]; legacy {
+				mapping[alias.model] = target
+			}
+			continue
+		}
+		if mappingHasWildcardForModel(mapping, alias.model) {
+			continue
+		}
+		mapping[alias.model] = target
+	}
+}
+
+func mappingHasWildcardForModel(mapping map[string]string, model string) bool {
+	for pattern := range mapping {
+		if matchWildcard(pattern, model) {
+			return true
+		}
+	}
+	return false
+}
+
 func normalizeRequestedModelForLookup(platform, requestedModel string) string {
 	trimmed := strings.TrimSpace(requestedModel)
 	if trimmed == "" {

backend/internal/service/account_wildcard_test.go

@@ -4,6 +4,8 @@ package service
 
 import (
 	"testing"
+
+	"github.com/Wei-Shaw/sub2api/internal/domain"
 )
 
 func TestMatchWildcard(t *testing.T) {
@@ -320,6 +322,86 @@ func TestAccountGetMappedModel(t *testing.T) {
 	}
 }
 
+func TestAccountGetModelMapping_AntigravityNormalizesGemini31ProAliases(t *testing.T) {
+	t.Parallel()
+
+	account := &Account{
+		Platform: PlatformAntigravity,
+		Credentials: map[string]any{
+			"model_mapping": map[string]any{
+				domain.AntigravityGemini31ProAgentModel: domain.AntigravityGemini31ProAgentModel,
+				"gemini-3.1-pro-high":                   "gemini-3.1-pro-high",
+				"gemini-3.1-pro-preview":                "gemini-3.1-pro-high",
+			},
+		},
+	}
+
+	mapping := account.GetModelMapping()
+
+	if got := mapping["gemini-3.1-pro"]; got != domain.AntigravityGemini31ProAgentModel {
+		t.Fatalf("expected gemini-3.1-pro to map to %q, got %q", domain.AntigravityGemini31ProAgentModel, got)
+	}
+	if got := mapping["gemini-3.1-pro-high"]; got != domain.AntigravityGemini31ProAgentModel {
+		t.Fatalf("expected gemini-3.1-pro-high to map to %q, got %q", domain.AntigravityGemini31ProAgentModel, got)
+	}
+	if got := mapping["gemini-3.1-pro-preview"]; got != domain.AntigravityGemini31ProAgentModel {
+		t.Fatalf("expected gemini-3.1-pro-preview to map to %q, got %q", domain.AntigravityGemini31ProAgentModel, got)
+	}
+}
+
+func TestAccountGetModelMapping_AntigravityPreservesGemini31ProOverrides(t *testing.T) {
+	t.Parallel()
+
+	account := &Account{
+		Platform: PlatformAntigravity,
+		Credentials: map[string]any{
+			"model_mapping": map[string]any{
+				domain.AntigravityGemini31ProAgentModel: domain.AntigravityGemini31ProAgentModel,
+				"gemini-3.1-pro-high":                   "custom-high",
+				"gemini-3.1-pro-preview":                "custom-preview",
+			},
+		},
+	}
+
+	mapping := account.GetModelMapping()
+
+	if got := mapping["gemini-3.1-pro-high"]; got != "custom-high" {
+		t.Fatalf("expected gemini-3.1-pro-high override to be preserved, got %q", got)
+	}
+	if got := mapping["gemini-3.1-pro-preview"]; got != "custom-preview" {
+		t.Fatalf("expected gemini-3.1-pro-preview override to be preserved, got %q", got)
+	}
+	if got := mapping["gemini-3.1-pro"]; got != domain.AntigravityGemini31ProAgentModel {
+		t.Fatalf("expected gemini-3.1-pro alias to default to %q, got %q", domain.AntigravityGemini31ProAgentModel, got)
+	}
+}
+
+func TestAccountGetModelMapping_AntigravityGemini31ProAliasesRespectWildcard(t *testing.T) {
+	t.Parallel()
+
+	account := &Account{
+		Platform: PlatformAntigravity,
+		Credentials: map[string]any{
+			"model_mapping": map[string]any{
+				domain.AntigravityGemini31ProAgentModel: domain.AntigravityGemini31ProAgentModel,
+				"gemini-3.1-*":                          "custom-wildcard",
+			},
+		},
+	}
+
+	mapping := account.GetModelMapping()
+
+	if got := mapping["gemini-3.1-pro"]; got != "" {
+		t.Fatalf("expected gemini-3.1-pro exact alias to stay unset when wildcard exists, got %q", got)
+	}
+	if got := mapping["gemini-3.1-pro-high"]; got != "" {
+		t.Fatalf("expected gemini-3.1-pro-high exact alias to stay unset when wildcard exists, got %q", got)
+	}
+	if got := mapping["gemini-3.1-pro-preview"]; got != "" {
+		t.Fatalf("expected gemini-3.1-pro-preview exact alias to stay unset when wildcard exists, got %q", got)
+	}
+}
+
 func TestAccountResolveMappedModel(t *testing.T) {
 	tests := []struct {
 		name           string