Merge PR #213: feat(openai): 支持 OpenAI Responses API 标准内容格式

* fix(auth): 修复 RefreshToken 使用过期 token 时的 nil pointer panic

问题分析：
- RefreshToken 允许过期 token 继续流程（用于无感刷新）
- 但 ValidateToken 在 token 过期时返回 nil claims
- 导致后续访问 claims.UserID 时触发 panic

修复方案：
- 修改 ValidateToken，在检测到 ErrTokenExpired 时仍然返回 claims
- jwt-go 在解析时即使遇到过期错误，token.Claims 仍会被填充
- 这样 RefreshToken 可以正常获取用户信息并生成新 token

新增测试：
- TestAuthService_ValidateToken_ExpiredReturnsClaimsWithError
- TestAuthService_RefreshToken_ExpiredTokenNoPanic

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* fix(auth): 修复邮件验证服务未配置时可绕过验证的安全漏洞

当邮件验证开启但 emailService 未配置时，原逻辑允许用户绕过验证直接注册。
现在会返回 ErrServiceUnavailable 拒绝注册，确保配置错误不会导致安全问题。

- 在验证码检查前先检查 emailService 是否配置
- 添加日志记录帮助发现配置问题
- 新增单元测试覆盖该场景

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

---------

Co-authored-by: yangjianbo <yangjianbo@leagsoft.com>
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

backend/ent/group.go

@@ -51,6 +51,10 @@ type Group struct {
 	ImagePrice2k *float64 `json:"image_price_2k,omitempty"`
 	// ImagePrice4k holds the value of the "image_price_4k" field.
 	ImagePrice4k *float64 `json:"image_price_4k,omitempty"`
+	// 是否仅允许 Claude Code 客户端
+	ClaudeCodeOnly bool `json:"claude_code_only,omitempty"`
+	// 非 Claude Code 请求降级使用的分组 ID
+	FallbackGroupID *int64 `json:"fallback_group_id,omitempty"`
 	// Edges holds the relations/edges for other nodes in the graph.
 	// The values are being populated by the GroupQuery when eager-loading is set.
 	Edges        GroupEdges `json:"edges"`
@@ -157,11 +161,11 @@ func (*Group) scanValues(columns []string) ([]any, error) {
 	values := make([]any, len(columns))
 	for i := range columns {
 		switch columns[i] {
-		case group.FieldIsExclusive:
+		case group.FieldIsExclusive, group.FieldClaudeCodeOnly:
 			values[i] = new(sql.NullBool)
 		case group.FieldRateMultiplier, group.FieldDailyLimitUsd, group.FieldWeeklyLimitUsd, group.FieldMonthlyLimitUsd, group.FieldImagePrice1k, group.FieldImagePrice2k, group.FieldImagePrice4k:
 			values[i] = new(sql.NullFloat64)
-		case group.FieldID, group.FieldDefaultValidityDays:
+		case group.FieldID, group.FieldDefaultValidityDays, group.FieldFallbackGroupID:
 			values[i] = new(sql.NullInt64)
 		case group.FieldName, group.FieldDescription, group.FieldStatus, group.FieldPlatform, group.FieldSubscriptionType:
 			values[i] = new(sql.NullString)
@@ -298,6 +302,19 @@ func (_m *Group) assignValues(columns []string, values []any) error {
 				_m.ImagePrice4k = new(float64)
 				*_m.ImagePrice4k = value.Float64
 			}
+		case group.FieldClaudeCodeOnly:
+			if value, ok := values[i].(*sql.NullBool); !ok {
+				return fmt.Errorf("unexpected type %T for field claude_code_only", values[i])
+			} else if value.Valid {
+				_m.ClaudeCodeOnly = value.Bool
+			}
+		case group.FieldFallbackGroupID:
+			if value, ok := values[i].(*sql.NullInt64); !ok {
+				return fmt.Errorf("unexpected type %T for field fallback_group_id", values[i])
+			} else if value.Valid {
+				_m.FallbackGroupID = new(int64)
+				*_m.FallbackGroupID = value.Int64
+			}
 		default:
 			_m.selectValues.Set(columns[i], values[i])
 		}
@@ -440,6 +457,14 @@ func (_m *Group) String() string {
 		builder.WriteString("image_price_4k=")
 		builder.WriteString(fmt.Sprintf("%v", *v))
 	}
+	builder.WriteString(", ")
+	builder.WriteString("claude_code_only=")
+	builder.WriteString(fmt.Sprintf("%v", _m.ClaudeCodeOnly))
+	builder.WriteString(", ")
+	if v := _m.FallbackGroupID; v != nil {
+		builder.WriteString("fallback_group_id=")
+		builder.WriteString(fmt.Sprintf("%v", *v))
+	}
 	builder.WriteByte(')')
 	return builder.String()
 }

backend/ent/group/group.go

@@ -49,6 +49,10 @@ const (
 	FieldImagePrice2k = "image_price_2k"
 	// FieldImagePrice4k holds the string denoting the image_price_4k field in the database.
 	FieldImagePrice4k = "image_price_4k"
+	// FieldClaudeCodeOnly holds the string denoting the claude_code_only field in the database.
+	FieldClaudeCodeOnly = "claude_code_only"
+	// FieldFallbackGroupID holds the string denoting the fallback_group_id field in the database.
+	FieldFallbackGroupID = "fallback_group_id"
 	// EdgeAPIKeys holds the string denoting the api_keys edge name in mutations.
 	EdgeAPIKeys = "api_keys"
 	// EdgeRedeemCodes holds the string denoting the redeem_codes edge name in mutations.
@@ -141,6 +145,8 @@ var Columns = []string{
 	FieldImagePrice1k,
 	FieldImagePrice2k,
 	FieldImagePrice4k,
+	FieldClaudeCodeOnly,
+	FieldFallbackGroupID,
 }
 
 var (
@@ -196,6 +202,8 @@ var (
 	SubscriptionTypeValidator func(string) error
 	// DefaultDefaultValidityDays holds the default value on creation for the "default_validity_days" field.
 	DefaultDefaultValidityDays int
+	// DefaultClaudeCodeOnly holds the default value on creation for the "claude_code_only" field.
+	DefaultClaudeCodeOnly bool
 )
 
 // OrderOption defines the ordering options for the Group queries.
@@ -291,6 +299,16 @@ func ByImagePrice4k(opts ...sql.OrderTermOption) OrderOption {
 	return sql.OrderByField(FieldImagePrice4k, opts...).ToFunc()
 }
 
+// ByClaudeCodeOnly orders the results by the claude_code_only field.
+func ByClaudeCodeOnly(opts ...sql.OrderTermOption) OrderOption {
+	return sql.OrderByField(FieldClaudeCodeOnly, opts...).ToFunc()
+}
+
+// ByFallbackGroupID orders the results by the fallback_group_id field.
+func ByFallbackGroupID(opts ...sql.OrderTermOption) OrderOption {
+	return sql.OrderByField(FieldFallbackGroupID, opts...).ToFunc()
+}
+
 // ByAPIKeysCount orders the results by api_keys count.
 func ByAPIKeysCount(opts ...sql.OrderTermOption) OrderOption {
 	return func(s *sql.Selector) {

backend/ent/group/where.go

@@ -140,6 +140,16 @@ func ImagePrice4k(v float64) predicate.Group {
 	return predicate.Group(sql.FieldEQ(FieldImagePrice4k, v))
 }
 
+// ClaudeCodeOnly applies equality check predicate on the "claude_code_only" field. It's identical to ClaudeCodeOnlyEQ.
+func ClaudeCodeOnly(v bool) predicate.Group {
+	return predicate.Group(sql.FieldEQ(FieldClaudeCodeOnly, v))
+}
+
+// FallbackGroupID applies equality check predicate on the "fallback_group_id" field. It's identical to FallbackGroupIDEQ.
+func FallbackGroupID(v int64) predicate.Group {
+	return predicate.Group(sql.FieldEQ(FieldFallbackGroupID, v))
+}
+
 // CreatedAtEQ applies the EQ predicate on the "created_at" field.
 func CreatedAtEQ(v time.Time) predicate.Group {
 	return predicate.Group(sql.FieldEQ(FieldCreatedAt, v))
@@ -995,6 +1005,66 @@ func ImagePrice4kNotNil() predicate.Group {
 	return predicate.Group(sql.FieldNotNull(FieldImagePrice4k))
 }
 
+// ClaudeCodeOnlyEQ applies the EQ predicate on the "claude_code_only" field.
+func ClaudeCodeOnlyEQ(v bool) predicate.Group {
+	return predicate.Group(sql.FieldEQ(FieldClaudeCodeOnly, v))
+}
+
+// ClaudeCodeOnlyNEQ applies the NEQ predicate on the "claude_code_only" field.
+func ClaudeCodeOnlyNEQ(v bool) predicate.Group {
+	return predicate.Group(sql.FieldNEQ(FieldClaudeCodeOnly, v))
+}
+
+// FallbackGroupIDEQ applies the EQ predicate on the "fallback_group_id" field.
+func FallbackGroupIDEQ(v int64) predicate.Group {
+	return predicate.Group(sql.FieldEQ(FieldFallbackGroupID, v))
+}
+
+// FallbackGroupIDNEQ applies the NEQ predicate on the "fallback_group_id" field.
+func FallbackGroupIDNEQ(v int64) predicate.Group {
+	return predicate.Group(sql.FieldNEQ(FieldFallbackGroupID, v))
+}
+
+// FallbackGroupIDIn applies the In predicate on the "fallback_group_id" field.
+func FallbackGroupIDIn(vs ...int64) predicate.Group {
+	return predicate.Group(sql.FieldIn(FieldFallbackGroupID, vs...))
+}
+
+// FallbackGroupIDNotIn applies the NotIn predicate on the "fallback_group_id" field.
+func FallbackGroupIDNotIn(vs ...int64) predicate.Group {
+	return predicate.Group(sql.FieldNotIn(FieldFallbackGroupID, vs...))
+}
+
+// FallbackGroupIDGT applies the GT predicate on the "fallback_group_id" field.
+func FallbackGroupIDGT(v int64) predicate.Group {
+	return predicate.Group(sql.FieldGT(FieldFallbackGroupID, v))
+}
+
+// FallbackGroupIDGTE applies the GTE predicate on the "fallback_group_id" field.
+func FallbackGroupIDGTE(v int64) predicate.Group {
+	return predicate.Group(sql.FieldGTE(FieldFallbackGroupID, v))
+}
+
+// FallbackGroupIDLT applies the LT predicate on the "fallback_group_id" field.
+func FallbackGroupIDLT(v int64) predicate.Group {
+	return predicate.Group(sql.FieldLT(FieldFallbackGroupID, v))
+}
+
+// FallbackGroupIDLTE applies the LTE predicate on the "fallback_group_id" field.
+func FallbackGroupIDLTE(v int64) predicate.Group {
+	return predicate.Group(sql.FieldLTE(FieldFallbackGroupID, v))
+}
+
+// FallbackGroupIDIsNil applies the IsNil predicate on the "fallback_group_id" field.
+func FallbackGroupIDIsNil() predicate.Group {
+	return predicate.Group(sql.FieldIsNull(FieldFallbackGroupID))
+}
+
+// FallbackGroupIDNotNil applies the NotNil predicate on the "fallback_group_id" field.
+func FallbackGroupIDNotNil() predicate.Group {
+	return predicate.Group(sql.FieldNotNull(FieldFallbackGroupID))
+}
+
 // HasAPIKeys applies the HasEdge predicate on the "api_keys" edge.
 func HasAPIKeys() predicate.Group {
 	return predicate.Group(func(s *sql.Selector) {

backend/ent/group_create.go

@@ -258,6 +258,34 @@ func (_c *GroupCreate) SetNillableImagePrice4k(v *float64) *GroupCreate {
 	return _c
 }
 
+// SetClaudeCodeOnly sets the "claude_code_only" field.
+func (_c *GroupCreate) SetClaudeCodeOnly(v bool) *GroupCreate {
+	_c.mutation.SetClaudeCodeOnly(v)
+	return _c
+}
+
+// SetNillableClaudeCodeOnly sets the "claude_code_only" field if the given value is not nil.
+func (_c *GroupCreate) SetNillableClaudeCodeOnly(v *bool) *GroupCreate {
+	if v != nil {
+		_c.SetClaudeCodeOnly(*v)
+	}
+	return _c
+}
+
+// SetFallbackGroupID sets the "fallback_group_id" field.
+func (_c *GroupCreate) SetFallbackGroupID(v int64) *GroupCreate {
+	_c.mutation.SetFallbackGroupID(v)
+	return _c
+}
+
+// SetNillableFallbackGroupID sets the "fallback_group_id" field if the given value is not nil.
+func (_c *GroupCreate) SetNillableFallbackGroupID(v *int64) *GroupCreate {
+	if v != nil {
+		_c.SetFallbackGroupID(*v)
+	}
+	return _c
+}
+
 // AddAPIKeyIDs adds the "api_keys" edge to the APIKey entity by IDs.
 func (_c *GroupCreate) AddAPIKeyIDs(ids ...int64) *GroupCreate {
 	_c.mutation.AddAPIKeyIDs(ids...)
@@ -423,6 +451,10 @@ func (_c *GroupCreate) defaults() error {
 		v := group.DefaultDefaultValidityDays
 		_c.mutation.SetDefaultValidityDays(v)
 	}
+	if _, ok := _c.mutation.ClaudeCodeOnly(); !ok {
+		v := group.DefaultClaudeCodeOnly
+		_c.mutation.SetClaudeCodeOnly(v)
+	}
 	return nil
 }
 
@@ -475,6 +507,9 @@ func (_c *GroupCreate) check() error {
 	if _, ok := _c.mutation.DefaultValidityDays(); !ok {
 		return &ValidationError{Name: "default_validity_days", err: errors.New(`ent: missing required field "Group.default_validity_days"`)}
 	}
+	if _, ok := _c.mutation.ClaudeCodeOnly(); !ok {
+		return &ValidationError{Name: "claude_code_only", err: errors.New(`ent: missing required field "Group.claude_code_only"`)}
+	}
 	return nil
 }
 
@@ -570,6 +605,14 @@ func (_c *GroupCreate) createSpec() (*Group, *sqlgraph.CreateSpec) {
 		_spec.SetField(group.FieldImagePrice4k, field.TypeFloat64, value)
 		_node.ImagePrice4k = &value
 	}
+	if value, ok := _c.mutation.ClaudeCodeOnly(); ok {
+		_spec.SetField(group.FieldClaudeCodeOnly, field.TypeBool, value)
+		_node.ClaudeCodeOnly = value
+	}
+	if value, ok := _c.mutation.FallbackGroupID(); ok {
+		_spec.SetField(group.FieldFallbackGroupID, field.TypeInt64, value)
+		_node.FallbackGroupID = &value
+	}
 	if nodes := _c.mutation.APIKeysIDs(); len(nodes) > 0 {
 		edge := &sqlgraph.EdgeSpec{
 			Rel:     sqlgraph.O2M,
@@ -1014,6 +1057,42 @@ func (u *GroupUpsert) ClearImagePrice4k() *GroupUpsert {
 	return u
 }
 
+// SetClaudeCodeOnly sets the "claude_code_only" field.
+func (u *GroupUpsert) SetClaudeCodeOnly(v bool) *GroupUpsert {
+	u.Set(group.FieldClaudeCodeOnly, v)
+	return u
+}
+
+// UpdateClaudeCodeOnly sets the "claude_code_only" field to the value that was provided on create.
+func (u *GroupUpsert) UpdateClaudeCodeOnly() *GroupUpsert {
+	u.SetExcluded(group.FieldClaudeCodeOnly)
+	return u
+}
+
+// SetFallbackGroupID sets the "fallback_group_id" field.
+func (u *GroupUpsert) SetFallbackGroupID(v int64) *GroupUpsert {
+	u.Set(group.FieldFallbackGroupID, v)
+	return u
+}
+
+// UpdateFallbackGroupID sets the "fallback_group_id" field to the value that was provided on create.
+func (u *GroupUpsert) UpdateFallbackGroupID() *GroupUpsert {
+	u.SetExcluded(group.FieldFallbackGroupID)
+	return u
+}
+
+// AddFallbackGroupID adds v to the "fallback_group_id" field.
+func (u *GroupUpsert) AddFallbackGroupID(v int64) *GroupUpsert {
+	u.Add(group.FieldFallbackGroupID, v)
+	return u
+}
+
+// ClearFallbackGroupID clears the value of the "fallback_group_id" field.
+func (u *GroupUpsert) ClearFallbackGroupID() *GroupUpsert {
+	u.SetNull(group.FieldFallbackGroupID)
+	return u
+}
+
 // UpdateNewValues updates the mutable fields using the new values that were set on create.
 // Using this option is equivalent to using:
 //
@@ -1395,6 +1474,48 @@ func (u *GroupUpsertOne) ClearImagePrice4k() *GroupUpsertOne {
 	})
 }
 
+// SetClaudeCodeOnly sets the "claude_code_only" field.
+func (u *GroupUpsertOne) SetClaudeCodeOnly(v bool) *GroupUpsertOne {
+	return u.Update(func(s *GroupUpsert) {
+		s.SetClaudeCodeOnly(v)
+	})
+}
+
+// UpdateClaudeCodeOnly sets the "claude_code_only" field to the value that was provided on create.
+func (u *GroupUpsertOne) UpdateClaudeCodeOnly() *GroupUpsertOne {
+	return u.Update(func(s *GroupUpsert) {
+		s.UpdateClaudeCodeOnly()
+	})
+}
+
+// SetFallbackGroupID sets the "fallback_group_id" field.
+func (u *GroupUpsertOne) SetFallbackGroupID(v int64) *GroupUpsertOne {
+	return u.Update(func(s *GroupUpsert) {
+		s.SetFallbackGroupID(v)
+	})
+}
+
+// AddFallbackGroupID adds v to the "fallback_group_id" field.
+func (u *GroupUpsertOne) AddFallbackGroupID(v int64) *GroupUpsertOne {
+	return u.Update(func(s *GroupUpsert) {
+		s.AddFallbackGroupID(v)
+	})
+}
+
+// UpdateFallbackGroupID sets the "fallback_group_id" field to the value that was provided on create.
+func (u *GroupUpsertOne) UpdateFallbackGroupID() *GroupUpsertOne {
+	return u.Update(func(s *GroupUpsert) {
+		s.UpdateFallbackGroupID()
+	})
+}
+
+// ClearFallbackGroupID clears the value of the "fallback_group_id" field.
+func (u *GroupUpsertOne) ClearFallbackGroupID() *GroupUpsertOne {
+	return u.Update(func(s *GroupUpsert) {
+		s.ClearFallbackGroupID()
+	})
+}
+
 // Exec executes the query.
 func (u *GroupUpsertOne) Exec(ctx context.Context) error {
 	if len(u.create.conflict) == 0 {
@@ -1942,6 +2063,48 @@ func (u *GroupUpsertBulk) ClearImagePrice4k() *GroupUpsertBulk {
 	})
 }
 
+// SetClaudeCodeOnly sets the "claude_code_only" field.
+func (u *GroupUpsertBulk) SetClaudeCodeOnly(v bool) *GroupUpsertBulk {
+	return u.Update(func(s *GroupUpsert) {
+		s.SetClaudeCodeOnly(v)
+	})
+}
+
+// UpdateClaudeCodeOnly sets the "claude_code_only" field to the value that was provided on create.
+func (u *GroupUpsertBulk) UpdateClaudeCodeOnly() *GroupUpsertBulk {
+	return u.Update(func(s *GroupUpsert) {
+		s.UpdateClaudeCodeOnly()
+	})
+}
+
+// SetFallbackGroupID sets the "fallback_group_id" field.
+func (u *GroupUpsertBulk) SetFallbackGroupID(v int64) *GroupUpsertBulk {
+	return u.Update(func(s *GroupUpsert) {
+		s.SetFallbackGroupID(v)
+	})
+}
+
+// AddFallbackGroupID adds v to the "fallback_group_id" field.
+func (u *GroupUpsertBulk) AddFallbackGroupID(v int64) *GroupUpsertBulk {
+	return u.Update(func(s *GroupUpsert) {
+		s.AddFallbackGroupID(v)
+	})
+}
+
+// UpdateFallbackGroupID sets the "fallback_group_id" field to the value that was provided on create.
+func (u *GroupUpsertBulk) UpdateFallbackGroupID() *GroupUpsertBulk {
+	return u.Update(func(s *GroupUpsert) {
+		s.UpdateFallbackGroupID()
+	})
+}
+
+// ClearFallbackGroupID clears the value of the "fallback_group_id" field.
+func (u *GroupUpsertBulk) ClearFallbackGroupID() *GroupUpsertBulk {
+	return u.Update(func(s *GroupUpsert) {
+		s.ClearFallbackGroupID()
+	})
+}
+
 // Exec executes the query.
 func (u *GroupUpsertBulk) Exec(ctx context.Context) error {
 	if u.create.err != nil {

backend/ent/group_update.go

@@ -354,6 +354,47 @@ func (_u *GroupUpdate) ClearImagePrice4k() *GroupUpdate {
 	return _u
 }
 
+// SetClaudeCodeOnly sets the "claude_code_only" field.
+func (_u *GroupUpdate) SetClaudeCodeOnly(v bool) *GroupUpdate {
+	_u.mutation.SetClaudeCodeOnly(v)
+	return _u
+}
+
+// SetNillableClaudeCodeOnly sets the "claude_code_only" field if the given value is not nil.
+func (_u *GroupUpdate) SetNillableClaudeCodeOnly(v *bool) *GroupUpdate {
+	if v != nil {
+		_u.SetClaudeCodeOnly(*v)
+	}
+	return _u
+}
+
+// SetFallbackGroupID sets the "fallback_group_id" field.
+func (_u *GroupUpdate) SetFallbackGroupID(v int64) *GroupUpdate {
+	_u.mutation.ResetFallbackGroupID()
+	_u.mutation.SetFallbackGroupID(v)
+	return _u
+}
+
+// SetNillableFallbackGroupID sets the "fallback_group_id" field if the given value is not nil.
+func (_u *GroupUpdate) SetNillableFallbackGroupID(v *int64) *GroupUpdate {
+	if v != nil {
+		_u.SetFallbackGroupID(*v)
+	}
+	return _u
+}
+
+// AddFallbackGroupID adds value to the "fallback_group_id" field.
+func (_u *GroupUpdate) AddFallbackGroupID(v int64) *GroupUpdate {
+	_u.mutation.AddFallbackGroupID(v)
+	return _u
+}
+
+// ClearFallbackGroupID clears the value of the "fallback_group_id" field.
+func (_u *GroupUpdate) ClearFallbackGroupID() *GroupUpdate {
+	_u.mutation.ClearFallbackGroupID()
+	return _u
+}
+
 // AddAPIKeyIDs adds the "api_keys" edge to the APIKey entity by IDs.
 func (_u *GroupUpdate) AddAPIKeyIDs(ids ...int64) *GroupUpdate {
 	_u.mutation.AddAPIKeyIDs(ids...)
@@ -750,6 +791,18 @@ func (_u *GroupUpdate) sqlSave(ctx context.Context) (_node int, err error) {
 	if _u.mutation.ImagePrice4kCleared() {
 		_spec.ClearField(group.FieldImagePrice4k, field.TypeFloat64)
 	}
+	if value, ok := _u.mutation.ClaudeCodeOnly(); ok {
+		_spec.SetField(group.FieldClaudeCodeOnly, field.TypeBool, value)
+	}
+	if value, ok := _u.mutation.FallbackGroupID(); ok {
+		_spec.SetField(group.FieldFallbackGroupID, field.TypeInt64, value)
+	}
+	if value, ok := _u.mutation.AddedFallbackGroupID(); ok {
+		_spec.AddField(group.FieldFallbackGroupID, field.TypeInt64, value)
+	}
+	if _u.mutation.FallbackGroupIDCleared() {
+		_spec.ClearField(group.FieldFallbackGroupID, field.TypeInt64)
+	}
 	if _u.mutation.APIKeysCleared() {
 		edge := &sqlgraph.EdgeSpec{
 			Rel:     sqlgraph.O2M,
@@ -1384,6 +1437,47 @@ func (_u *GroupUpdateOne) ClearImagePrice4k() *GroupUpdateOne {
 	return _u
 }
 
+// SetClaudeCodeOnly sets the "claude_code_only" field.
+func (_u *GroupUpdateOne) SetClaudeCodeOnly(v bool) *GroupUpdateOne {
+	_u.mutation.SetClaudeCodeOnly(v)
+	return _u
+}
+
+// SetNillableClaudeCodeOnly sets the "claude_code_only" field if the given value is not nil.
+func (_u *GroupUpdateOne) SetNillableClaudeCodeOnly(v *bool) *GroupUpdateOne {
+	if v != nil {
+		_u.SetClaudeCodeOnly(*v)
+	}
+	return _u
+}
+
+// SetFallbackGroupID sets the "fallback_group_id" field.
+func (_u *GroupUpdateOne) SetFallbackGroupID(v int64) *GroupUpdateOne {
+	_u.mutation.ResetFallbackGroupID()
+	_u.mutation.SetFallbackGroupID(v)
+	return _u
+}
+
+// SetNillableFallbackGroupID sets the "fallback_group_id" field if the given value is not nil.
+func (_u *GroupUpdateOne) SetNillableFallbackGroupID(v *int64) *GroupUpdateOne {
+	if v != nil {
+		_u.SetFallbackGroupID(*v)
+	}
+	return _u
+}
+
+// AddFallbackGroupID adds value to the "fallback_group_id" field.
+func (_u *GroupUpdateOne) AddFallbackGroupID(v int64) *GroupUpdateOne {
+	_u.mutation.AddFallbackGroupID(v)
+	return _u
+}
+
+// ClearFallbackGroupID clears the value of the "fallback_group_id" field.
+func (_u *GroupUpdateOne) ClearFallbackGroupID() *GroupUpdateOne {
+	_u.mutation.ClearFallbackGroupID()
+	return _u
+}
+
 // AddAPIKeyIDs adds the "api_keys" edge to the APIKey entity by IDs.
 func (_u *GroupUpdateOne) AddAPIKeyIDs(ids ...int64) *GroupUpdateOne {
 	_u.mutation.AddAPIKeyIDs(ids...)
@@ -1810,6 +1904,18 @@ func (_u *GroupUpdateOne) sqlSave(ctx context.Context) (_node *Group, err error)
 	if _u.mutation.ImagePrice4kCleared() {
 		_spec.ClearField(group.FieldImagePrice4k, field.TypeFloat64)
 	}
+	if value, ok := _u.mutation.ClaudeCodeOnly(); ok {
+		_spec.SetField(group.FieldClaudeCodeOnly, field.TypeBool, value)
+	}
+	if value, ok := _u.mutation.FallbackGroupID(); ok {
+		_spec.SetField(group.FieldFallbackGroupID, field.TypeInt64, value)
+	}
+	if value, ok := _u.mutation.AddedFallbackGroupID(); ok {
+		_spec.AddField(group.FieldFallbackGroupID, field.TypeInt64, value)
+	}
+	if _u.mutation.FallbackGroupIDCleared() {
+		_spec.ClearField(group.FieldFallbackGroupID, field.TypeInt64)
+	}
 	if _u.mutation.APIKeysCleared() {
 		edge := &sqlgraph.EdgeSpec{
 			Rel:     sqlgraph.O2M,

backend/ent/migrate/schema.go

@@ -221,6 +221,8 @@ var (
 		{Name: "image_price_1k", Type: field.TypeFloat64, Nullable: true, SchemaType: map[string]string{"postgres": "decimal(20,8)"}},
 		{Name: "image_price_2k", Type: field.TypeFloat64, Nullable: true, SchemaType: map[string]string{"postgres": "decimal(20,8)"}},
 		{Name: "image_price_4k", Type: field.TypeFloat64, Nullable: true, SchemaType: map[string]string{"postgres": "decimal(20,8)"}},
+		{Name: "claude_code_only", Type: field.TypeBool, Default: false},
+		{Name: "fallback_group_id", Type: field.TypeInt64, Nullable: true},
 	}
 	// GroupsTable holds the schema information for the "groups" table.
 	GroupsTable = &schema.Table{

backend/ent/mutation.go

@@ -3590,6 +3590,9 @@ type GroupMutation struct {
 	addimage_price_2k        *float64
 	image_price_4k           *float64
 	addimage_price_4k        *float64
+	claude_code_only         *bool
+	fallback_group_id        *int64
+	addfallback_group_id     *int64
 	clearedFields            map[string]struct{}
 	api_keys                 map[int64]struct{}
 	removedapi_keys          map[int64]struct{}
@@ -4594,6 +4597,112 @@ func (m *GroupMutation) ResetImagePrice4k() {
 	delete(m.clearedFields, group.FieldImagePrice4k)
 }
 
+// SetClaudeCodeOnly sets the "claude_code_only" field.
+func (m *GroupMutation) SetClaudeCodeOnly(b bool) {
+	m.claude_code_only = &b
+}
+
+// ClaudeCodeOnly returns the value of the "claude_code_only" field in the mutation.
+func (m *GroupMutation) ClaudeCodeOnly() (r bool, exists bool) {
+	v := m.claude_code_only
+	if v == nil {
+		return
+	}
+	return *v, true
+}
+
+// OldClaudeCodeOnly returns the old "claude_code_only" field's value of the Group entity.
+// If the Group object wasn't provided to the builder, the object is fetched from the database.
+// An error is returned if the mutation operation is not UpdateOne, or the database query fails.
+func (m *GroupMutation) OldClaudeCodeOnly(ctx context.Context) (v bool, err error) {
+	if !m.op.Is(OpUpdateOne) {
+		return v, errors.New("OldClaudeCodeOnly is only allowed on UpdateOne operations")
+	}
+	if m.id == nil || m.oldValue == nil {
+		return v, errors.New("OldClaudeCodeOnly requires an ID field in the mutation")
+	}
+	oldValue, err := m.oldValue(ctx)
+	if err != nil {
+		return v, fmt.Errorf("querying old value for OldClaudeCodeOnly: %w", err)
+	}
+	return oldValue.ClaudeCodeOnly, nil
+}
+
+// ResetClaudeCodeOnly resets all changes to the "claude_code_only" field.
+func (m *GroupMutation) ResetClaudeCodeOnly() {
+	m.claude_code_only = nil
+}
+
+// SetFallbackGroupID sets the "fallback_group_id" field.
+func (m *GroupMutation) SetFallbackGroupID(i int64) {
+	m.fallback_group_id = &i
+	m.addfallback_group_id = nil
+}
+
+// FallbackGroupID returns the value of the "fallback_group_id" field in the mutation.
+func (m *GroupMutation) FallbackGroupID() (r int64, exists bool) {
+	v := m.fallback_group_id
+	if v == nil {
+		return
+	}
+	return *v, true
+}
+
+// OldFallbackGroupID returns the old "fallback_group_id" field's value of the Group entity.
+// If the Group object wasn't provided to the builder, the object is fetched from the database.
+// An error is returned if the mutation operation is not UpdateOne, or the database query fails.
+func (m *GroupMutation) OldFallbackGroupID(ctx context.Context) (v *int64, err error) {
+	if !m.op.Is(OpUpdateOne) {
+		return v, errors.New("OldFallbackGroupID is only allowed on UpdateOne operations")
+	}
+	if m.id == nil || m.oldValue == nil {
+		return v, errors.New("OldFallbackGroupID requires an ID field in the mutation")
+	}
+	oldValue, err := m.oldValue(ctx)
+	if err != nil {
+		return v, fmt.Errorf("querying old value for OldFallbackGroupID: %w", err)
+	}
+	return oldValue.FallbackGroupID, nil
+}
+
+// AddFallbackGroupID adds i to the "fallback_group_id" field.
+func (m *GroupMutation) AddFallbackGroupID(i int64) {
+	if m.addfallback_group_id != nil {
+		*m.addfallback_group_id += i
+	} else {
+		m.addfallback_group_id = &i
+	}
+}
+
+// AddedFallbackGroupID returns the value that was added to the "fallback_group_id" field in this mutation.
+func (m *GroupMutation) AddedFallbackGroupID() (r int64, exists bool) {
+	v := m.addfallback_group_id
+	if v == nil {
+		return
+	}
+	return *v, true
+}
+
+// ClearFallbackGroupID clears the value of the "fallback_group_id" field.
+func (m *GroupMutation) ClearFallbackGroupID() {
+	m.fallback_group_id = nil
+	m.addfallback_group_id = nil
+	m.clearedFields[group.FieldFallbackGroupID] = struct{}{}
+}
+
+// FallbackGroupIDCleared returns if the "fallback_group_id" field was cleared in this mutation.
+func (m *GroupMutation) FallbackGroupIDCleared() bool {
+	_, ok := m.clearedFields[group.FieldFallbackGroupID]
+	return ok
+}
+
+// ResetFallbackGroupID resets all changes to the "fallback_group_id" field.
+func (m *GroupMutation) ResetFallbackGroupID() {
+	m.fallback_group_id = nil
+	m.addfallback_group_id = nil
+	delete(m.clearedFields, group.FieldFallbackGroupID)
+}
+
 // AddAPIKeyIDs adds the "api_keys" edge to the APIKey entity by ids.
 func (m *GroupMutation) AddAPIKeyIDs(ids ...int64) {
 	if m.api_keys == nil {
@@ -4952,7 +5061,7 @@ func (m *GroupMutation) Type() string {
 // order to get all numeric fields that were incremented/decremented, call
 // AddedFields().
 func (m *GroupMutation) Fields() []string {
-	fields := make([]string, 0, 17)
+	fields := make([]string, 0, 19)
 	if m.created_at != nil {
 		fields = append(fields, group.FieldCreatedAt)
 	}
@@ -5004,6 +5113,12 @@ func (m *GroupMutation) Fields() []string {
 	if m.image_price_4k != nil {
 		fields = append(fields, group.FieldImagePrice4k)
 	}
+	if m.claude_code_only != nil {
+		fields = append(fields, group.FieldClaudeCodeOnly)
+	}
+	if m.fallback_group_id != nil {
+		fields = append(fields, group.FieldFallbackGroupID)
+	}
 	return fields
 }
 
@@ -5046,6 +5161,10 @@ func (m *GroupMutation) Field(name string) (ent.Value, bool) {
 		return m.ImagePrice2k()
 	case group.FieldImagePrice4k:
 		return m.ImagePrice4k()
+	case group.FieldClaudeCodeOnly:
+		return m.ClaudeCodeOnly()
+	case group.FieldFallbackGroupID:
+		return m.FallbackGroupID()
 	}
 	return nil, false
 }
@@ -5089,6 +5208,10 @@ func (m *GroupMutation) OldField(ctx context.Context, name string) (ent.Value, e
 		return m.OldImagePrice2k(ctx)
 	case group.FieldImagePrice4k:
 		return m.OldImagePrice4k(ctx)
+	case group.FieldClaudeCodeOnly:
+		return m.OldClaudeCodeOnly(ctx)
+	case group.FieldFallbackGroupID:
+		return m.OldFallbackGroupID(ctx)
 	}
 	return nil, fmt.Errorf("unknown Group field %s", name)
 }
@@ -5217,6 +5340,20 @@ func (m *GroupMutation) SetField(name string, value ent.Value) error {
 		}
 		m.SetImagePrice4k(v)
 		return nil
+	case group.FieldClaudeCodeOnly:
+		v, ok := value.(bool)
+		if !ok {
+			return fmt.Errorf("unexpected type %T for field %s", value, name)
+		}
+		m.SetClaudeCodeOnly(v)
+		return nil
+	case group.FieldFallbackGroupID:
+		v, ok := value.(int64)
+		if !ok {
+			return fmt.Errorf("unexpected type %T for field %s", value, name)
+		}
+		m.SetFallbackGroupID(v)
+		return nil
 	}
 	return fmt.Errorf("unknown Group field %s", name)
 }
@@ -5249,6 +5386,9 @@ func (m *GroupMutation) AddedFields() []string {
 	if m.addimage_price_4k != nil {
 		fields = append(fields, group.FieldImagePrice4k)
 	}
+	if m.addfallback_group_id != nil {
+		fields = append(fields, group.FieldFallbackGroupID)
+	}
 	return fields
 }
 
@@ -5273,6 +5413,8 @@ func (m *GroupMutation) AddedField(name string) (ent.Value, bool) {
 		return m.AddedImagePrice2k()
 	case group.FieldImagePrice4k:
 		return m.AddedImagePrice4k()
+	case group.FieldFallbackGroupID:
+		return m.AddedFallbackGroupID()
 	}
 	return nil, false
 }
@@ -5338,6 +5480,13 @@ func (m *GroupMutation) AddField(name string, value ent.Value) error {
 		}
 		m.AddImagePrice4k(v)
 		return nil
+	case group.FieldFallbackGroupID:
+		v, ok := value.(int64)
+		if !ok {
+			return fmt.Errorf("unexpected type %T for field %s", value, name)
+		}
+		m.AddFallbackGroupID(v)
+		return nil
 	}
 	return fmt.Errorf("unknown Group numeric field %s", name)
 }
@@ -5370,6 +5519,9 @@ func (m *GroupMutation) ClearedFields() []string {
 	if m.FieldCleared(group.FieldImagePrice4k) {
 		fields = append(fields, group.FieldImagePrice4k)
 	}
+	if m.FieldCleared(group.FieldFallbackGroupID) {
+		fields = append(fields, group.FieldFallbackGroupID)
+	}
 	return fields
 }
 
@@ -5408,6 +5560,9 @@ func (m *GroupMutation) ClearField(name string) error {
 	case group.FieldImagePrice4k:
 		m.ClearImagePrice4k()
 		return nil
+	case group.FieldFallbackGroupID:
+		m.ClearFallbackGroupID()
+		return nil
 	}
 	return fmt.Errorf("unknown Group nullable field %s", name)
 }
@@ -5467,6 +5622,12 @@ func (m *GroupMutation) ResetField(name string) error {
 	case group.FieldImagePrice4k:
 		m.ResetImagePrice4k()
 		return nil
+	case group.FieldClaudeCodeOnly:
+		m.ResetClaudeCodeOnly()
+		return nil
+	case group.FieldFallbackGroupID:
+		m.ResetFallbackGroupID()
+		return nil
 	}
 	return fmt.Errorf("unknown Group field %s", name)
 }

backend/ent/runtime/runtime.go

@@ -270,6 +270,10 @@ func init() {
 	groupDescDefaultValidityDays := groupFields[10].Descriptor()
 	// group.DefaultDefaultValidityDays holds the default value on creation for the default_validity_days field.
 	group.DefaultDefaultValidityDays = groupDescDefaultValidityDays.Default.(int)
+	// groupDescClaudeCodeOnly is the schema descriptor for claude_code_only field.
+	groupDescClaudeCodeOnly := groupFields[14].Descriptor()
+	// group.DefaultClaudeCodeOnly holds the default value on creation for the claude_code_only field.
+	group.DefaultClaudeCodeOnly = groupDescClaudeCodeOnly.Default.(bool)
 	proxyMixin := schema.Proxy{}.Mixin()
 	proxyMixinHooks1 := proxyMixin[1].Hooks()
 	proxy.Hooks[0] = proxyMixinHooks1[0]

backend/ent/schema/group.go

@@ -86,6 +86,15 @@ func (Group) Fields() []ent.Field {
 			Optional().
 			Nillable().
 			SchemaType(map[string]string{dialect.Postgres: "decimal(20,8)"}),
+
+		// Claude Code 客户端限制 (added by migration 029)
+		field.Bool("claude_code_only").
+			Default(false).
+			Comment("是否仅允许 Claude Code 客户端"),
+		field.Int64("fallback_group_id").
+			Optional().
+			Nillable().
+			Comment("非 Claude Code 请求降级使用的分组 ID"),
 	}
 }
 
@@ -101,6 +110,8 @@ func (Group) Edges() []ent.Edge {
 		edge.From("allowed_users", User.Type).
 			Ref("allowed_groups").
 			Through("user_allowed_groups", UserAllowedGroup.Type),
+		// 注意：fallback_group_id 直接作为字段使用，不定义 edge
+		// 这样允许多个分组指向同一个降级分组（M2O 关系）
 	}
 }
 

backend/internal/handler/admin/group_handler.go

@@ -34,9 +34,11 @@ type CreateGroupRequest struct {
 	WeeklyLimitUSD   *float64 `json:"weekly_limit_usd"`
 	MonthlyLimitUSD  *float64 `json:"monthly_limit_usd"`
 	// 图片生成计费配置（antigravity 和 gemini 平台使用，负数表示清除配置）
-	ImagePrice1K *float64 `json:"image_price_1k"`
-	ImagePrice2K *float64 `json:"image_price_2k"`
-	ImagePrice4K *float64 `json:"image_price_4k"`
+	ImagePrice1K    *float64 `json:"image_price_1k"`
+	ImagePrice2K    *float64 `json:"image_price_2k"`
+	ImagePrice4K    *float64 `json:"image_price_4k"`
+	ClaudeCodeOnly  bool     `json:"claude_code_only"`
+	FallbackGroupID *int64   `json:"fallback_group_id"`
 }
 
 // UpdateGroupRequest represents update group request
@@ -52,9 +54,11 @@ type UpdateGroupRequest struct {
 	WeeklyLimitUSD   *float64 `json:"weekly_limit_usd"`
 	MonthlyLimitUSD  *float64 `json:"monthly_limit_usd"`
 	// 图片生成计费配置（antigravity 和 gemini 平台使用，负数表示清除配置）
-	ImagePrice1K *float64 `json:"image_price_1k"`
-	ImagePrice2K *float64 `json:"image_price_2k"`
-	ImagePrice4K *float64 `json:"image_price_4k"`
+	ImagePrice1K    *float64 `json:"image_price_1k"`
+	ImagePrice2K    *float64 `json:"image_price_2k"`
+	ImagePrice4K    *float64 `json:"image_price_4k"`
+	ClaudeCodeOnly  *bool    `json:"claude_code_only"`
+	FallbackGroupID *int64   `json:"fallback_group_id"`
 }
 
 // List handles listing all groups with pagination
@@ -150,6 +154,8 @@ func (h *GroupHandler) Create(c *gin.Context) {
 		ImagePrice1K:     req.ImagePrice1K,
 		ImagePrice2K:     req.ImagePrice2K,
 		ImagePrice4K:     req.ImagePrice4K,
+		ClaudeCodeOnly:   req.ClaudeCodeOnly,
+		FallbackGroupID:  req.FallbackGroupID,
 	})
 	if err != nil {
 		response.ErrorFrom(c, err)
@@ -188,6 +194,8 @@ func (h *GroupHandler) Update(c *gin.Context) {
 		ImagePrice1K:     req.ImagePrice1K,
 		ImagePrice2K:     req.ImagePrice2K,
 		ImagePrice4K:     req.ImagePrice4K,
+		ClaudeCodeOnly:   req.ClaudeCodeOnly,
+		FallbackGroupID:  req.FallbackGroupID,
 	})
 	if err != nil {
 		response.ErrorFrom(c, err)

backend/internal/handler/admin/proxy_handler.go

@@ -52,15 +52,15 @@ func (h *ProxyHandler) List(c *gin.Context) {
 	status := c.Query("status")
 	search := c.Query("search")
 
-	proxies, total, err := h.adminService.ListProxies(c.Request.Context(), page, pageSize, protocol, status, search)
+	proxies, total, err := h.adminService.ListProxiesWithAccountCount(c.Request.Context(), page, pageSize, protocol, status, search)
 	if err != nil {
 		response.ErrorFrom(c, err)
 		return
 	}
 
-	out := make([]dto.Proxy, 0, len(proxies))
+	out := make([]dto.ProxyWithAccountCount, 0, len(proxies))
 	for i := range proxies {
-		out = append(out, *dto.ProxyFromService(&proxies[i]))
+		out = append(out, *dto.ProxyWithAccountCountFromService(&proxies[i]))
 	}
 	response.Paginated(c, out, total, page, pageSize)
 }

backend/internal/handler/dto/mappers.go

@@ -85,6 +85,8 @@ func GroupFromServiceShallow(g *service.Group) *Group {
 		ImagePrice1K:     g.ImagePrice1K,
 		ImagePrice2K:     g.ImagePrice2K,
 		ImagePrice4K:     g.ImagePrice4K,
+		ClaudeCodeOnly:   g.ClaudeCodeOnly,
+		FallbackGroupID:  g.FallbackGroupID,
 		CreatedAt:        g.CreatedAt,
 		UpdatedAt:        g.UpdatedAt,
 		AccountCount:     g.AccountCount,
@@ -280,6 +282,7 @@ func usageLogFromServiceBase(l *service.UsageLog, account *AccountSummary) *Usag
 		FirstTokenMs:          l.FirstTokenMs,
 		ImageCount:            l.ImageCount,
 		ImageSize:             l.ImageSize,
+		UserAgent:             l.UserAgent,
 		CreatedAt:             l.CreatedAt,
 		User:                  UserFromServiceShallow(l.User),
 		APIKey:                APIKeyFromService(l.APIKey),

backend/internal/handler/dto/types.go

@@ -52,6 +52,10 @@ type Group struct {
 	ImagePrice2K *float64 `json:"image_price_2k"`
 	ImagePrice4K *float64 `json:"image_price_4k"`
 
+	// Claude Code 客户端限制
+	ClaudeCodeOnly  bool   `json:"claude_code_only"`
+	FallbackGroupID *int64 `json:"fallback_group_id"`
+
 	CreatedAt time.Time `json:"created_at"`
 	UpdatedAt time.Time `json:"updated_at"`
 
@@ -180,6 +184,9 @@ type UsageLog struct {
 	ImageCount int     `json:"image_count"`
 	ImageSize  *string `json:"image_size"`
 
+	// User-Agent
+	UserAgent *string `json:"user_agent"`
+
 	CreatedAt time.Time `json:"created_at"`
 
 	User         *User             `json:"user,omitempty"`

backend/internal/handler/gateway_handler.go

@@ -96,6 +96,9 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
 	reqModel := parsedReq.Model
 	reqStream := parsedReq.Stream
 
+	// 设置 Claude Code 客户端标识到 context（用于分组限制检查）
+	SetClaudeCodeClientContext(c, body)
+
 	// 验证 model 必填
 	if reqModel == "" {
 		h.errorResponse(c, http.StatusBadRequest, "invalid_request_error", "model is required")
@@ -229,7 +232,7 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
 					h.handleConcurrencyError(c, err, "account", streamStarted)
 					return
 				}
-				if err := h.gatewayService.BindStickySession(c.Request.Context(), sessionKey, account.ID); err != nil {
+				if err := h.gatewayService.BindStickySession(c.Request.Context(), apiKey.GroupID, sessionKey, account.ID); err != nil {
 					log.Printf("Bind sticky session failed: %v", err)
 				}
 			}
@@ -357,7 +360,7 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
 				h.handleConcurrencyError(c, err, "account", streamStarted)
 				return
 			}
-			if err := h.gatewayService.BindStickySession(c.Request.Context(), sessionKey, account.ID); err != nil {
+			if err := h.gatewayService.BindStickySession(c.Request.Context(), apiKey.GroupID, sessionKey, account.ID); err != nil {
 				log.Printf("Bind sticky session failed: %v", err)
 			}
 		}
@@ -683,6 +686,9 @@ func (h *GatewayHandler) CountTokens(c *gin.Context) {
 		return
 	}
 
+	// 设置 Claude Code 客户端标识到 context（用于分组限制检查）
+	SetClaudeCodeClientContext(c, body)
+
 	// 验证 model 必填
 	if parsedReq.Model == "" {
 		h.errorResponse(c, http.StatusBadRequest, "invalid_request_error", "model is required")

backend/internal/handler/gateway_helper.go

@@ -2,6 +2,7 @@ package handler
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"math/rand"
 	"net/http"
@@ -13,6 +14,26 @@ import (
 	"github.com/gin-gonic/gin"
 )
 
+// claudeCodeValidator is a singleton validator for Claude Code client detection
+var claudeCodeValidator = service.NewClaudeCodeValidator()
+
+// SetClaudeCodeClientContext 检查请求是否来自 Claude Code 客户端，并设置到 context 中
+// 返回更新后的 context
+func SetClaudeCodeClientContext(c *gin.Context, body []byte) {
+	// 解析请求体为 map
+	var bodyMap map[string]any
+	if len(body) > 0 {
+		_ = json.Unmarshal(body, &bodyMap)
+	}
+
+	// 验证是否为 Claude Code 客户端
+	isClaudeCode := claudeCodeValidator.Validate(c.Request, bodyMap)
+
+	// 更新 request context
+	ctx := service.SetClaudeCodeClient(c.Request.Context(), isClaudeCode)
+	c.Request = c.Request.WithContext(ctx)
+}
+
 // 并发槽位等待相关常量
 //
 // 性能优化说明：

backend/internal/handler/gemini_v1beta_handler.go

@@ -203,6 +203,10 @@ func (h *GatewayHandler) GeminiV1BetaModels(c *gin.Context) {
 
 	// 3) select account (sticky session based on request body)
 	parsedReq, _ := service.ParseGatewayRequest(body)
+
+	// 设置 Claude Code 客户端标识到 context（用于分组限制检查）
+	SetClaudeCodeClientContext(c, body)
+
 	sessionHash := h.gatewayService.GenerateSessionHash(parsedReq)
 	sessionKey := sessionHash
 	if sessionHash != "" {
@@ -262,7 +266,7 @@ func (h *GatewayHandler) GeminiV1BetaModels(c *gin.Context) {
 				googleError(c, http.StatusTooManyRequests, err.Error())
 				return
 			}
-			if err := h.gatewayService.BindStickySession(c.Request.Context(), sessionKey, account.ID); err != nil {
+			if err := h.gatewayService.BindStickySession(c.Request.Context(), apiKey.GroupID, sessionKey, account.ID); err != nil {
 				log.Printf("Bind sticky session failed: %v", err)
 			}
 		}

backend/internal/handler/openai_gateway_handler.go

@@ -206,7 +206,7 @@ func (h *OpenAIGatewayHandler) Responses(c *gin.Context) {
 				h.handleConcurrencyError(c, err, "account", streamStarted)
 				return
 			}
-			if err := h.gatewayService.BindStickySession(c.Request.Context(), sessionHash, account.ID); err != nil {
+			if err := h.gatewayService.BindStickySession(c.Request.Context(), apiKey.GroupID, sessionHash, account.ID); err != nil {
 				log.Printf("Bind sticky session failed: %v", err)
 			}
 		}

backend/internal/pkg/antigravity/client.go

@@ -5,8 +5,11 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
+	"log"
+	"net"
 	"net/http"
 	"net/url"
 	"strings"
@@ -22,10 +25,10 @@ func resolveHost(urlStr string) string {
 	return parsed.Host
 }
 
-// NewAPIRequest 创建 Antigravity API 请求（v1internal 端点）
-func NewAPIRequest(ctx context.Context, action, accessToken string, body []byte) (*http.Request, error) {
+// NewAPIRequestWithURL 使用指定的 base URL 创建 Antigravity API 请求（v1internal 端点）
+func NewAPIRequestWithURL(ctx context.Context, baseURL, action, accessToken string, body []byte) (*http.Request, error) {
 	// 构建 URL，流式请求添加 ?alt=sse 参数
-	apiURL := fmt.Sprintf("%s/v1internal:%s", BaseURL, action)
+	apiURL := fmt.Sprintf("%s/v1internal:%s", baseURL, action)
 	isStream := action == "streamGenerateContent"
 	if isStream {
 		apiURL += "?alt=sse"
@@ -53,11 +56,15 @@ func NewAPIRequest(ctx context.Context, action, accessToken string, body []byte)
 		req.Host = host
 	}
 
-	// 注意：requestType 已在 JSON body 的 V1InternalRequest 中设置，不需要 HTTP Header
-
 	return req, nil
 }
 
+// NewAPIRequest 使用默认 URL 创建 Antigravity API 请求（v1internal 端点）
+// 向后兼容：仅使用默认 BaseURL
+func NewAPIRequest(ctx context.Context, action, accessToken string, body []byte) (*http.Request, error) {
+	return NewAPIRequestWithURL(ctx, BaseURL, action, accessToken, body)
+}
+
 // TokenResponse Google OAuth token 响应
 type TokenResponse struct {
 	AccessToken  string `json:"access_token"`
@@ -164,6 +171,38 @@ func NewClient(proxyURL string) *Client {
 	}
 }
 
+// isConnectionError 判断是否为连接错误（网络超时、DNS 失败、连接拒绝）
+func isConnectionError(err error) bool {
+	if err == nil {
+		return false
+	}
+
+	// 检查超时错误
+	var netErr net.Error
+	if errors.As(err, &netErr) && netErr.Timeout() {
+		return true
+	}
+
+	// 检查连接错误（DNS 失败、连接拒绝）
+	var opErr *net.OpError
+	if errors.As(err, &opErr) {
+		return true
+	}
+
+	// 检查 URL 错误
+	var urlErr *url.Error
+	return errors.As(err, &urlErr)
+}
+
+// shouldFallbackToNextURL 判断是否应切换到下一个 URL
+// 仅连接错误和 HTTP 429 触发 URL 降级
+func shouldFallbackToNextURL(err error, statusCode int) bool {
+	if isConnectionError(err) {
+		return true
+	}
+	return statusCode == http.StatusTooManyRequests
+}
+
 // ExchangeCode 用 authorization code 交换 token
 func (c *Client) ExchangeCode(ctx context.Context, code, codeVerifier string) (*TokenResponse, error) {
 	params := url.Values{}
@@ -272,6 +311,7 @@ func (c *Client) GetUserInfo(ctx context.Context, accessToken string) (*UserInfo
 }
 
 // LoadCodeAssist 获取账户信息，返回解析后的结构体和原始 JSON
+// 支持 URL fallback：sandbox → daily → prod
 func (c *Client) LoadCodeAssist(ctx context.Context, accessToken string) (*LoadCodeAssistResponse, map[string]any, error) {
 	reqBody := LoadCodeAssistRequest{}
 	reqBody.Metadata.IDEType = "ANTIGRAVITY"
@@ -281,40 +321,65 @@ func (c *Client) LoadCodeAssist(ctx context.Context, accessToken string) (*LoadC
 		return nil, nil, fmt.Errorf("序列化请求失败: %w", err)
 	}
 
-	url := BaseURL + "/v1internal:loadCodeAssist"
-	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, strings.NewReader(string(bodyBytes)))
-	if err != nil {
-		return nil, nil, fmt.Errorf("创建请求失败: %w", err)
-	}
-	req.Header.Set("Authorization", "Bearer "+accessToken)
-	req.Header.Set("Content-Type", "application/json")
-	req.Header.Set("User-Agent", UserAgent)
-
-	resp, err := c.httpClient.Do(req)
-	if err != nil {
-		return nil, nil, fmt.Errorf("loadCodeAssist 请求失败: %w", err)
-	}
-	defer func() { _ = resp.Body.Close() }()
-
-	respBodyBytes, err := io.ReadAll(resp.Body)
-	if err != nil {
-		return nil, nil, fmt.Errorf("读取响应失败: %w", err)
+	// 获取可用的 URL 列表
+	availableURLs := DefaultURLAvailability.GetAvailableURLs()
+	if len(availableURLs) == 0 {
+		availableURLs = BaseURLs // 所有 URL 都不可用时，重试所有
 	}
 
-	if resp.StatusCode != http.StatusOK {
-		return nil, nil, fmt.Errorf("loadCodeAssist 失败 (HTTP %d): %s", resp.StatusCode, string(respBodyBytes))
+	var lastErr error
+	for urlIdx, baseURL := range availableURLs {
+		apiURL := baseURL + "/v1internal:loadCodeAssist"
+		req, err := http.NewRequestWithContext(ctx, http.MethodPost, apiURL, strings.NewReader(string(bodyBytes)))
+		if err != nil {
+			lastErr = fmt.Errorf("创建请求失败: %w", err)
+			continue
+		}
+		req.Header.Set("Authorization", "Bearer "+accessToken)
+		req.Header.Set("Content-Type", "application/json")
+		req.Header.Set("User-Agent", UserAgent)
+
+		resp, err := c.httpClient.Do(req)
+		if err != nil {
+			lastErr = fmt.Errorf("loadCodeAssist 请求失败: %w", err)
+			if shouldFallbackToNextURL(err, 0) && urlIdx < len(availableURLs)-1 {
+				DefaultURLAvailability.MarkUnavailable(baseURL)
+				log.Printf("[antigravity] loadCodeAssist URL fallback: %s -> %s", baseURL, availableURLs[urlIdx+1])
+				continue
+			}
+			return nil, nil, lastErr
+		}
+
+		respBodyBytes, err := io.ReadAll(resp.Body)
+		_ = resp.Body.Close() // 立即关闭，避免循环内 defer 导致的资源泄漏
+		if err != nil {
+			return nil, nil, fmt.Errorf("读取响应失败: %w", err)
+		}
+
+		// 检查是否需要 URL 降级
+		if shouldFallbackToNextURL(nil, resp.StatusCode) && urlIdx < len(availableURLs)-1 {
+			DefaultURLAvailability.MarkUnavailable(baseURL)
+			log.Printf("[antigravity] loadCodeAssist URL fallback (HTTP %d): %s -> %s", resp.StatusCode, baseURL, availableURLs[urlIdx+1])
+			continue
+		}
+
+		if resp.StatusCode != http.StatusOK {
+			return nil, nil, fmt.Errorf("loadCodeAssist 失败 (HTTP %d): %s", resp.StatusCode, string(respBodyBytes))
+		}
+
+		var loadResp LoadCodeAssistResponse
+		if err := json.Unmarshal(respBodyBytes, &loadResp); err != nil {
+			return nil, nil, fmt.Errorf("响应解析失败: %w", err)
+		}
+
+		// 解析原始 JSON 为 map
+		var rawResp map[string]any
+		_ = json.Unmarshal(respBodyBytes, &rawResp)
+
+		return &loadResp, rawResp, nil
 	}
 
-	var loadResp LoadCodeAssistResponse
-	if err := json.Unmarshal(respBodyBytes, &loadResp); err != nil {
-		return nil, nil, fmt.Errorf("响应解析失败: %w", err)
-	}
-
-	// 解析原始 JSON 为 map
-	var rawResp map[string]any
-	_ = json.Unmarshal(respBodyBytes, &rawResp)
-
-	return &loadResp, rawResp, nil
+	return nil, nil, lastErr
 }
 
 // ModelQuotaInfo 模型配额信息
@@ -339,6 +404,7 @@ type FetchAvailableModelsResponse struct {
 }
 
 // FetchAvailableModels 获取可用模型和配额信息，返回解析后的结构体和原始 JSON
+// 支持 URL fallback：sandbox → daily → prod
 func (c *Client) FetchAvailableModels(ctx context.Context, accessToken, projectID string) (*FetchAvailableModelsResponse, map[string]any, error) {
 	reqBody := FetchAvailableModelsRequest{Project: projectID}
 	bodyBytes, err := json.Marshal(reqBody)
@@ -346,38 +412,63 @@ func (c *Client) FetchAvailableModels(ctx context.Context, accessToken, projectI
 		return nil, nil, fmt.Errorf("序列化请求失败: %w", err)
 	}
 
-	apiURL := BaseURL + "/v1internal:fetchAvailableModels"
-	req, err := http.NewRequestWithContext(ctx, http.MethodPost, apiURL, strings.NewReader(string(bodyBytes)))
-	if err != nil {
-		return nil, nil, fmt.Errorf("创建请求失败: %w", err)
-	}
-	req.Header.Set("Authorization", "Bearer "+accessToken)
-	req.Header.Set("Content-Type", "application/json")
-	req.Header.Set("User-Agent", UserAgent)
-
-	resp, err := c.httpClient.Do(req)
-	if err != nil {
-		return nil, nil, fmt.Errorf("fetchAvailableModels 请求失败: %w", err)
-	}
-	defer func() { _ = resp.Body.Close() }()
-
-	respBodyBytes, err := io.ReadAll(resp.Body)
-	if err != nil {
-		return nil, nil, fmt.Errorf("读取响应失败: %w", err)
+	// 获取可用的 URL 列表
+	availableURLs := DefaultURLAvailability.GetAvailableURLs()
+	if len(availableURLs) == 0 {
+		availableURLs = BaseURLs // 所有 URL 都不可用时，重试所有
 	}
 
-	if resp.StatusCode != http.StatusOK {
-		return nil, nil, fmt.Errorf("fetchAvailableModels 失败 (HTTP %d): %s", resp.StatusCode, string(respBodyBytes))
+	var lastErr error
+	for urlIdx, baseURL := range availableURLs {
+		apiURL := baseURL + "/v1internal:fetchAvailableModels"
+		req, err := http.NewRequestWithContext(ctx, http.MethodPost, apiURL, strings.NewReader(string(bodyBytes)))
+		if err != nil {
+			lastErr = fmt.Errorf("创建请求失败: %w", err)
+			continue
+		}
+		req.Header.Set("Authorization", "Bearer "+accessToken)
+		req.Header.Set("Content-Type", "application/json")
+		req.Header.Set("User-Agent", UserAgent)
+
+		resp, err := c.httpClient.Do(req)
+		if err != nil {
+			lastErr = fmt.Errorf("fetchAvailableModels 请求失败: %w", err)
+			if shouldFallbackToNextURL(err, 0) && urlIdx < len(availableURLs)-1 {
+				DefaultURLAvailability.MarkUnavailable(baseURL)
+				log.Printf("[antigravity] fetchAvailableModels URL fallback: %s -> %s", baseURL, availableURLs[urlIdx+1])
+				continue
+			}
+			return nil, nil, lastErr
+		}
+
+		respBodyBytes, err := io.ReadAll(resp.Body)
+		_ = resp.Body.Close() // 立即关闭，避免循环内 defer 导致的资源泄漏
+		if err != nil {
+			return nil, nil, fmt.Errorf("读取响应失败: %w", err)
+		}
+
+		// 检查是否需要 URL 降级
+		if shouldFallbackToNextURL(nil, resp.StatusCode) && urlIdx < len(availableURLs)-1 {
+			DefaultURLAvailability.MarkUnavailable(baseURL)
+			log.Printf("[antigravity] fetchAvailableModels URL fallback (HTTP %d): %s -> %s", resp.StatusCode, baseURL, availableURLs[urlIdx+1])
+			continue
+		}
+
+		if resp.StatusCode != http.StatusOK {
+			return nil, nil, fmt.Errorf("fetchAvailableModels 失败 (HTTP %d): %s", resp.StatusCode, string(respBodyBytes))
+		}
+
+		var modelsResp FetchAvailableModelsResponse
+		if err := json.Unmarshal(respBodyBytes, &modelsResp); err != nil {
+			return nil, nil, fmt.Errorf("响应解析失败: %w", err)
+		}
+
+		// 解析原始 JSON 为 map
+		var rawResp map[string]any
+		_ = json.Unmarshal(respBodyBytes, &rawResp)
+
+		return &modelsResp, rawResp, nil
 	}
 
-	var modelsResp FetchAvailableModelsResponse
-	if err := json.Unmarshal(respBodyBytes, &modelsResp); err != nil {
-		return nil, nil, fmt.Errorf("响应解析失败: %w", err)
-	}
-
-	// 解析原始 JSON 为 map
-	var rawResp map[string]any
-	_ = json.Unmarshal(respBodyBytes, &rawResp)
-
-	return &modelsResp, rawResp, nil
+	return nil, nil, lastErr
 }

backend/internal/pkg/antigravity/oauth.go

@@ -32,17 +32,79 @@ const (
 		"https://www.googleapis.com/auth/cclog " +
 		"https://www.googleapis.com/auth/experimentsandconfigs"
 
-	// API 端点
-	// 优先使用 sandbox daily URL，配额更宽松
-	BaseURL = "https://daily-cloudcode-pa.sandbox.googleapis.com"
-
 	// User-Agent（模拟官方客户端）
 	UserAgent = "antigravity/1.104.0 darwin/arm64"
 
 	// Session 过期时间
 	SessionTTL = 30 * time.Minute
+
+	// URL 可用性 TTL（不可用 URL 的恢复时间）
+	URLAvailabilityTTL = 5 * time.Minute
 )
 
+// BaseURLs 定义 Antigravity API 端点，按优先级排序
+// fallback 顺序: sandbox → daily → prod
+var BaseURLs = []string{
+	"https://daily-cloudcode-pa.sandbox.googleapis.com", // sandbox
+	"https://daily-cloudcode-pa.googleapis.com",         // daily
+	"https://cloudcode-pa.googleapis.com",               // prod
+}
+
+// BaseURL 默认 URL（保持向后兼容）
+var BaseURL = BaseURLs[0]
+
+// URLAvailability 管理 URL 可用性状态（带 TTL 自动恢复）
+type URLAvailability struct {
+	mu          sync.RWMutex
+	unavailable map[string]time.Time // URL -> 恢复时间
+	ttl         time.Duration
+}
+
+// DefaultURLAvailability 全局 URL 可用性管理器
+var DefaultURLAvailability = NewURLAvailability(URLAvailabilityTTL)
+
+// NewURLAvailability 创建 URL 可用性管理器
+func NewURLAvailability(ttl time.Duration) *URLAvailability {
+	return &URLAvailability{
+		unavailable: make(map[string]time.Time),
+		ttl:         ttl,
+	}
+}
+
+// MarkUnavailable 标记 URL 临时不可用
+func (u *URLAvailability) MarkUnavailable(url string) {
+	u.mu.Lock()
+	defer u.mu.Unlock()
+	u.unavailable[url] = time.Now().Add(u.ttl)
+}
+
+// IsAvailable 检查 URL 是否可用
+func (u *URLAvailability) IsAvailable(url string) bool {
+	u.mu.RLock()
+	defer u.mu.RUnlock()
+	expiry, exists := u.unavailable[url]
+	if !exists {
+		return true
+	}
+	return time.Now().After(expiry)
+}
+
+// GetAvailableURLs 返回可用的 URL 列表（保持优先级顺序）
+func (u *URLAvailability) GetAvailableURLs() []string {
+	u.mu.RLock()
+	defer u.mu.RUnlock()
+
+	now := time.Now()
+	result := make([]string, 0, len(BaseURLs))
+	for _, url := range BaseURLs {
+		expiry, exists := u.unavailable[url]
+		if !exists || now.After(expiry) {
+			result = append(result, url)
+		}
+	}
+	return result
+}
+
 // OAuthSession 保存 OAuth 授权流程的临时状态
 type OAuthSession struct {
 	State        string    `json:"state"`

backend/internal/pkg/ctxkey/ctxkey.go

@@ -7,4 +7,6 @@ type Key string
 const (
 	// ForcePlatform 强制平台（用于 /antigravity 路由），由 middleware.ForcePlatform 设置
 	ForcePlatform Key = "ctx_force_platform"
+	// IsClaudeCodeClient 是否为 Claude Code 客户端，由中间件设置
+	IsClaudeCodeClient Key = "ctx_is_claude_code_client"
 )

backend/internal/pkg/geminicli/constants.go

@@ -27,10 +27,9 @@ const (
 	// https://www.googleapis.com/auth/generative-language.retriever (often with cloud-platform).
 	DefaultAIStudioScopes = "https://www.googleapis.com/auth/cloud-platform https://www.googleapis.com/auth/generative-language.retriever"
 
-	// DefaultScopes for Google One (personal Google accounts with Gemini access)
-	// Only used when a custom OAuth client is configured. When using the built-in Gemini CLI client,
-	// Google One uses DefaultCodeAssistScopes (same as code_assist) because the built-in client
-	// cannot request restricted scopes like generative-language.retriever or drive.readonly.
+	// DefaultGoogleOneScopes (DEPRECATED, no longer used)
+	// Google One now always uses the built-in Gemini CLI client with DefaultCodeAssistScopes.
+	// This constant is kept for backward compatibility but is not actively used.
 	DefaultGoogleOneScopes = "https://www.googleapis.com/auth/cloud-platform https://www.googleapis.com/auth/generative-language.retriever https://www.googleapis.com/auth/drive.readonly https://www.googleapis.com/auth/userinfo.email https://www.googleapis.com/auth/userinfo.profile"
 
 	// GeminiCLIRedirectURI is the redirect URI used by Gemini CLI for Code Assist OAuth.

backend/internal/pkg/geminicli/oauth.go

@@ -185,13 +185,9 @@ func EffectiveOAuthConfig(cfg OAuthConfig, oauthType string) (OAuthConfig, error
 				effective.Scopes = DefaultAIStudioScopes
 			}
 		case "google_one":
-			// Google One uses built-in Gemini CLI client (same as code_assist)
-			// Built-in client can't request restricted scopes like generative-language.retriever
-			if isBuiltinClient {
-				effective.Scopes = DefaultCodeAssistScopes
-			} else {
-				effective.Scopes = DefaultGoogleOneScopes
-			}
+			// Google One always uses built-in Gemini CLI client (same as code_assist)
+			// Built-in client can't request restricted scopes like generative-language.retriever or drive.readonly
+			effective.Scopes = DefaultCodeAssistScopes
 		default:
 			// Default to Code Assist scopes
 			effective.Scopes = DefaultCodeAssistScopes

backend/internal/pkg/geminicli/oauth_test.go

@@ -23,14 +23,14 @@ func TestEffectiveOAuthConfig_GoogleOne(t *testing.T) {
 			wantErr:      false,
 		},
 		{
-			name: "Google One with custom client",
+			name: "Google One always uses built-in client (even if custom credentials passed)",
 			input: OAuthConfig{
 				ClientID:     "custom-client-id",
 				ClientSecret: "custom-client-secret",
 			},
 			oauthType:    "google_one",
 			wantClientID: "custom-client-id",
-			wantScopes:   DefaultGoogleOneScopes,
+			wantScopes:   DefaultCodeAssistScopes, // Uses code assist scopes even with custom client
 			wantErr:      false,
 		},
 		{

backend/internal/repository/api_key_repo.go

@@ -325,6 +325,8 @@ func groupEntityToService(g *dbent.Group) *service.Group {
 		ImagePrice2K:        g.ImagePrice2k,
 		ImagePrice4K:        g.ImagePrice4k,
 		DefaultValidityDays: g.DefaultValidityDays,
+		ClaudeCodeOnly:      g.ClaudeCodeOnly,
+		FallbackGroupID:     g.FallbackGroupID,
 		CreatedAt:           g.CreatedAt,
 		UpdatedAt:           g.UpdatedAt,
 	}

backend/internal/repository/gateway_cache.go

@@ -2,6 +2,7 @@ package repository
 
 import (
 	"context"
+	"fmt"
 	"time"
 
 	"github.com/Wei-Shaw/sub2api/internal/service"
@@ -18,17 +19,23 @@ func NewGatewayCache(rdb *redis.Client) service.GatewayCache {
 	return &gatewayCache{rdb: rdb}
 }
 
-func (c *gatewayCache) GetSessionAccountID(ctx context.Context, sessionHash string) (int64, error) {
-	key := stickySessionPrefix + sessionHash
+// buildSessionKey 构建 session key，包含 groupID 实现分组隔离
+// 格式: sticky_session:{groupID}:{sessionHash}
+func buildSessionKey(groupID int64, sessionHash string) string {
+	return fmt.Sprintf("%s%d:%s", stickySessionPrefix, groupID, sessionHash)
+}
+
+func (c *gatewayCache) GetSessionAccountID(ctx context.Context, groupID int64, sessionHash string) (int64, error) {
+	key := buildSessionKey(groupID, sessionHash)
 	return c.rdb.Get(ctx, key).Int64()
 }
 
-func (c *gatewayCache) SetSessionAccountID(ctx context.Context, sessionHash string, accountID int64, ttl time.Duration) error {
-	key := stickySessionPrefix + sessionHash
+func (c *gatewayCache) SetSessionAccountID(ctx context.Context, groupID int64, sessionHash string, accountID int64, ttl time.Duration) error {
+	key := buildSessionKey(groupID, sessionHash)
 	return c.rdb.Set(ctx, key, accountID, ttl).Err()
 }
 
-func (c *gatewayCache) RefreshSessionTTL(ctx context.Context, sessionHash string, ttl time.Duration) error {
-	key := stickySessionPrefix + sessionHash
+func (c *gatewayCache) RefreshSessionTTL(ctx context.Context, groupID int64, sessionHash string, ttl time.Duration) error {
+	key := buildSessionKey(groupID, sessionHash)
 	return c.rdb.Expire(ctx, key, ttl).Err()
 }

backend/internal/repository/gateway_cache_integration_test.go

@@ -24,18 +24,19 @@ func (s *GatewayCacheSuite) SetupTest() {
 }
 
 func (s *GatewayCacheSuite) TestGetSessionAccountID_Missing() {
-	_, err := s.cache.GetSessionAccountID(s.ctx, "nonexistent")
+	_, err := s.cache.GetSessionAccountID(s.ctx, 1, "nonexistent")
 	require.True(s.T(), errors.Is(err, redis.Nil), "expected redis.Nil for missing session")
 }
 
 func (s *GatewayCacheSuite) TestSetAndGetSessionAccountID() {
 	sessionID := "s1"
 	accountID := int64(99)
+	groupID := int64(1)
 	sessionTTL := 1 * time.Minute
 
-	require.NoError(s.T(), s.cache.SetSessionAccountID(s.ctx, sessionID, accountID, sessionTTL), "SetSessionAccountID")
+	require.NoError(s.T(), s.cache.SetSessionAccountID(s.ctx, groupID, sessionID, accountID, sessionTTL), "SetSessionAccountID")
 
-	sid, err := s.cache.GetSessionAccountID(s.ctx, sessionID)
+	sid, err := s.cache.GetSessionAccountID(s.ctx, groupID, sessionID)
 	require.NoError(s.T(), err, "GetSessionAccountID")
 	require.Equal(s.T(), accountID, sid, "session id mismatch")
 }
@@ -43,11 +44,12 @@ func (s *GatewayCacheSuite) TestSetAndGetSessionAccountID() {
 func (s *GatewayCacheSuite) TestSessionAccountID_TTL() {
 	sessionID := "s2"
 	accountID := int64(100)
+	groupID := int64(1)
 	sessionTTL := 1 * time.Minute
 
-	require.NoError(s.T(), s.cache.SetSessionAccountID(s.ctx, sessionID, accountID, sessionTTL), "SetSessionAccountID")
+	require.NoError(s.T(), s.cache.SetSessionAccountID(s.ctx, groupID, sessionID, accountID, sessionTTL), "SetSessionAccountID")
 
-	sessionKey := stickySessionPrefix + sessionID
+	sessionKey := buildSessionKey(groupID, sessionID)
 	ttl, err := s.rdb.TTL(s.ctx, sessionKey).Result()
 	require.NoError(s.T(), err, "TTL sessionKey after Set")
 	s.AssertTTLWithin(ttl, 1*time.Second, sessionTTL)
@@ -56,14 +58,15 @@ func (s *GatewayCacheSuite) TestSessionAccountID_TTL() {
 func (s *GatewayCacheSuite) TestRefreshSessionTTL() {
 	sessionID := "s3"
 	accountID := int64(101)
+	groupID := int64(1)
 	initialTTL := 1 * time.Minute
 	refreshTTL := 3 * time.Minute
 
-	require.NoError(s.T(), s.cache.SetSessionAccountID(s.ctx, sessionID, accountID, initialTTL), "SetSessionAccountID")
+	require.NoError(s.T(), s.cache.SetSessionAccountID(s.ctx, groupID, sessionID, accountID, initialTTL), "SetSessionAccountID")
 
-	require.NoError(s.T(), s.cache.RefreshSessionTTL(s.ctx, sessionID, refreshTTL), "RefreshSessionTTL")
+	require.NoError(s.T(), s.cache.RefreshSessionTTL(s.ctx, groupID, sessionID, refreshTTL), "RefreshSessionTTL")
 
-	sessionKey := stickySessionPrefix + sessionID
+	sessionKey := buildSessionKey(groupID, sessionID)
 	ttl, err := s.rdb.TTL(s.ctx, sessionKey).Result()
 	require.NoError(s.T(), err, "TTL after Refresh")
 	s.AssertTTLWithin(ttl, 1*time.Second, refreshTTL)
@@ -71,18 +74,19 @@ func (s *GatewayCacheSuite) TestRefreshSessionTTL() {
 
 func (s *GatewayCacheSuite) TestRefreshSessionTTL_MissingKey() {
 	// RefreshSessionTTL on a missing key should not error (no-op)
-	err := s.cache.RefreshSessionTTL(s.ctx, "missing-session", 1*time.Minute)
+	err := s.cache.RefreshSessionTTL(s.ctx, 1, "missing-session", 1*time.Minute)
 	require.NoError(s.T(), err, "RefreshSessionTTL on missing key should not error")
 }
 
 func (s *GatewayCacheSuite) TestGetSessionAccountID_CorruptedValue() {
 	sessionID := "corrupted"
-	sessionKey := stickySessionPrefix + sessionID
+	groupID := int64(1)
+	sessionKey := buildSessionKey(groupID, sessionID)
 
 	// Set a non-integer value
 	require.NoError(s.T(), s.rdb.Set(s.ctx, sessionKey, "not-a-number", 1*time.Minute).Err(), "Set invalid value")
 
-	_, err := s.cache.GetSessionAccountID(s.ctx, sessionID)
+	_, err := s.cache.GetSessionAccountID(s.ctx, groupID, sessionID)
 	require.Error(s.T(), err, "expected error for corrupted value")
 	require.False(s.T(), errors.Is(err, redis.Nil), "expected parsing error, not redis.Nil")
 }

backend/internal/repository/gemini_oauth_client.go

@@ -30,14 +30,15 @@ func (c *geminiOAuthClient) ExchangeCode(ctx context.Context, oauthType, code, c
 
 	// Use different OAuth clients based on oauthType:
 	// - code_assist: always use built-in Gemini CLI OAuth client (public)
-	// - google_one: uses configured OAuth client when provided; otherwise falls back to built-in client
+	// - google_one: always use built-in Gemini CLI OAuth client (public)
 	// - ai_studio: requires a user-provided OAuth client
 	oauthCfgInput := geminicli.OAuthConfig{
 		ClientID:     c.cfg.Gemini.OAuth.ClientID,
 		ClientSecret: c.cfg.Gemini.OAuth.ClientSecret,
 		Scopes:       c.cfg.Gemini.OAuth.Scopes,
 	}
-	if oauthType == "code_assist" {
+	if oauthType == "code_assist" || oauthType == "google_one" {
+		// Force use of built-in Gemini CLI OAuth client
 		oauthCfgInput.ClientID = ""
 		oauthCfgInput.ClientSecret = ""
 	}
@@ -78,7 +79,8 @@ func (c *geminiOAuthClient) RefreshToken(ctx context.Context, oauthType, refresh
 		ClientSecret: c.cfg.Gemini.OAuth.ClientSecret,
 		Scopes:       c.cfg.Gemini.OAuth.Scopes,
 	}
-	if oauthType == "code_assist" {
+	if oauthType == "code_assist" || oauthType == "google_one" {
+		// Force use of built-in Gemini CLI OAuth client
 		oauthCfgInput.ClientID = ""
 		oauthCfgInput.ClientSecret = ""
 	}

backend/internal/repository/group_repo.go

@@ -46,7 +46,9 @@ func (r *groupRepository) Create(ctx context.Context, groupIn *service.Group) er
 		SetNillableImagePrice1k(groupIn.ImagePrice1K).
 		SetNillableImagePrice2k(groupIn.ImagePrice2K).
 		SetNillableImagePrice4k(groupIn.ImagePrice4K).
-		SetDefaultValidityDays(groupIn.DefaultValidityDays)
+		SetDefaultValidityDays(groupIn.DefaultValidityDays).
+		SetClaudeCodeOnly(groupIn.ClaudeCodeOnly).
+		SetNillableFallbackGroupID(groupIn.FallbackGroupID)
 
 	created, err := builder.Save(ctx)
 	if err == nil {
@@ -72,7 +74,7 @@ func (r *groupRepository) GetByID(ctx context.Context, id int64) (*service.Group
 }
 
 func (r *groupRepository) Update(ctx context.Context, groupIn *service.Group) error {
-	updated, err := r.client.Group.UpdateOneID(groupIn.ID).
+	builder := r.client.Group.UpdateOneID(groupIn.ID).
 		SetName(groupIn.Name).
 		SetDescription(groupIn.Description).
 		SetPlatform(groupIn.Platform).
@@ -87,7 +89,16 @@ func (r *groupRepository) Update(ctx context.Context, groupIn *service.Group) er
 		SetNillableImagePrice2k(groupIn.ImagePrice2K).
 		SetNillableImagePrice4k(groupIn.ImagePrice4K).
 		SetDefaultValidityDays(groupIn.DefaultValidityDays).
-		Save(ctx)
+		SetClaudeCodeOnly(groupIn.ClaudeCodeOnly)
+
+	// 处理 FallbackGroupID：nil 时清除，否则设置
+	if groupIn.FallbackGroupID != nil {
+		builder = builder.SetFallbackGroupID(*groupIn.FallbackGroupID)
+	} else {
+		builder = builder.ClearFallbackGroupID()
+	}
+
+	updated, err := builder.Save(ctx)
 	if err != nil {
 		return translatePersistenceError(err, service.ErrGroupNotFound, service.ErrGroupExists)
 	}

backend/internal/repository/proxy_repo.go

@@ -133,6 +133,55 @@ func (r *proxyRepository) ListWithFilters(ctx context.Context, params pagination
 	return outProxies, paginationResultFromTotal(int64(total), params), nil
 }
 
+// ListWithFiltersAndAccountCount lists proxies with filters and includes account count per proxy
+func (r *proxyRepository) ListWithFiltersAndAccountCount(ctx context.Context, params pagination.PaginationParams, protocol, status, search string) ([]service.ProxyWithAccountCount, *pagination.PaginationResult, error) {
+	q := r.client.Proxy.Query()
+	if protocol != "" {
+		q = q.Where(proxy.ProtocolEQ(protocol))
+	}
+	if status != "" {
+		q = q.Where(proxy.StatusEQ(status))
+	}
+	if search != "" {
+		q = q.Where(proxy.NameContainsFold(search))
+	}
+
+	total, err := q.Count(ctx)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	proxies, err := q.
+		Offset(params.Offset()).
+		Limit(params.Limit()).
+		Order(dbent.Desc(proxy.FieldID)).
+		All(ctx)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	// Get account counts
+	counts, err := r.GetAccountCountsForProxies(ctx)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	// Build result with account counts
+	result := make([]service.ProxyWithAccountCount, 0, len(proxies))
+	for i := range proxies {
+		proxyOut := proxyEntityToService(proxies[i])
+		if proxyOut == nil {
+			continue
+		}
+		result = append(result, service.ProxyWithAccountCount{
+			Proxy:        *proxyOut,
+			AccountCount: counts[proxyOut.ID],
+		})
+	}
+
+	return result, paginationResultFromTotal(int64(total), params), nil
+}
+
 func (r *proxyRepository) ListActive(ctx context.Context) ([]service.Proxy, error) {
 	proxies, err := r.client.Proxy.Query().
 		Where(proxy.StatusEQ(service.StatusActive)).

backend/internal/server/api_contract_test.go

@@ -243,7 +243,8 @@ func TestAPIContracts(t *testing.T) {
 							"first_token_ms": 50,
 							"image_count": 0,
 							"image_size": null,
-							"created_at": "2025-01-02T03:04:05Z"
+							"created_at": "2025-01-02T03:04:05Z",
+							"user_agent": null
 						}
 					],
 					"total": 1,

backend/internal/service/account_test_service.go

@@ -661,13 +661,7 @@ func (s *AccountTestService) processGeminiStream(c *gin.Context, body io.Reader)
 		}
 		if candidates, ok := data["candidates"].([]any); ok && len(candidates) > 0 {
 			if candidate, ok := candidates[0].(map[string]any); ok {
-				// Check for completion
-				if finishReason, ok := candidate["finishReason"].(string); ok && finishReason != "" {
-					s.sendEvent(c, TestEvent{Type: "test_complete", Success: true})
-					return nil
-				}
-
-				// Extract content
+				// Extract content first (before checking completion)
 				if content, ok := candidate["content"].(map[string]any); ok {
 					if parts, ok := content["parts"].([]any); ok {
 						for _, part := range parts {
@@ -679,6 +673,12 @@ func (s *AccountTestService) processGeminiStream(c *gin.Context, body io.Reader)
 						}
 					}
 				}
+
+				// Check for completion after extracting content
+				if finishReason, ok := candidate["finishReason"].(string); ok && finishReason != "" {
+					s.sendEvent(c, TestEvent{Type: "test_complete", Success: true})
+					return nil
+				}
 			}
 		}
 

backend/internal/service/admin_service.go

@@ -47,6 +47,7 @@ type AdminService interface {
 
 	// Proxy management
 	ListProxies(ctx context.Context, page, pageSize int, protocol, status, search string) ([]Proxy, int64, error)
+	ListProxiesWithAccountCount(ctx context.Context, page, pageSize int, protocol, status, search string) ([]ProxyWithAccountCount, int64, error)
 	GetAllProxies(ctx context.Context) ([]Proxy, error)
 	GetAllProxiesWithAccountCount(ctx context.Context) ([]ProxyWithAccountCount, error)
 	GetProxy(ctx context.Context, id int64) (*Proxy, error)
@@ -99,9 +100,11 @@ type CreateGroupInput struct {
 	WeeklyLimitUSD   *float64 // 周限额 (USD)
 	MonthlyLimitUSD  *float64 // 月限额 (USD)
 	// 图片生成计费配置（仅 antigravity 平台使用）
-	ImagePrice1K *float64
-	ImagePrice2K *float64
-	ImagePrice4K *float64
+	ImagePrice1K    *float64
+	ImagePrice2K    *float64
+	ImagePrice4K    *float64
+	ClaudeCodeOnly  bool   // 仅允许 Claude Code 客户端
+	FallbackGroupID *int64 // 降级分组 ID
 }
 
 type UpdateGroupInput struct {
@@ -116,9 +119,11 @@ type UpdateGroupInput struct {
 	WeeklyLimitUSD   *float64 // 周限额 (USD)
 	MonthlyLimitUSD  *float64 // 月限额 (USD)
 	// 图片生成计费配置（仅 antigravity 平台使用）
-	ImagePrice1K *float64
-	ImagePrice2K *float64
-	ImagePrice4K *float64
+	ImagePrice1K    *float64
+	ImagePrice2K    *float64
+	ImagePrice4K    *float64
+	ClaudeCodeOnly  *bool  // 仅允许 Claude Code 客户端
+	FallbackGroupID *int64 // 降级分组 ID
 }
 
 type CreateAccountInput struct {
@@ -515,6 +520,13 @@ func (s *adminServiceImpl) CreateGroup(ctx context.Context, input *CreateGroupIn
 	imagePrice2K := normalizePrice(input.ImagePrice2K)
 	imagePrice4K := normalizePrice(input.ImagePrice4K)
 
+	// 校验降级分组
+	if input.FallbackGroupID != nil {
+		if err := s.validateFallbackGroup(ctx, 0, *input.FallbackGroupID); err != nil {
+			return nil, err
+		}
+	}
+
 	group := &Group{
 		Name:             input.Name,
 		Description:      input.Description,
@@ -529,6 +541,8 @@ func (s *adminServiceImpl) CreateGroup(ctx context.Context, input *CreateGroupIn
 		ImagePrice1K:     imagePrice1K,
 		ImagePrice2K:     imagePrice2K,
 		ImagePrice4K:     imagePrice4K,
+		ClaudeCodeOnly:   input.ClaudeCodeOnly,
+		FallbackGroupID:  input.FallbackGroupID,
 	}
 	if err := s.groupRepo.Create(ctx, group); err != nil {
 		return nil, err
@@ -552,6 +566,29 @@ func normalizePrice(price *float64) *float64 {
 	return price
 }
 
+// validateFallbackGroup 校验降级分组的有效性
+// currentGroupID: 当前分组 ID（新建时为 0）
+// fallbackGroupID: 降级分组 ID
+func (s *adminServiceImpl) validateFallbackGroup(ctx context.Context, currentGroupID, fallbackGroupID int64) error {
+	// 不能将自己设置为降级分组
+	if currentGroupID > 0 && currentGroupID == fallbackGroupID {
+		return fmt.Errorf("cannot set self as fallback group")
+	}
+
+	// 检查降级分组是否存在
+	fallbackGroup, err := s.groupRepo.GetByID(ctx, fallbackGroupID)
+	if err != nil {
+		return fmt.Errorf("fallback group not found: %w", err)
+	}
+
+	// 降级分组不能启用 claude_code_only，否则会造成死循环
+	if fallbackGroup.ClaudeCodeOnly {
+		return fmt.Errorf("fallback group cannot have claude_code_only enabled")
+	}
+
+	return nil
+}
+
 func (s *adminServiceImpl) UpdateGroup(ctx context.Context, id int64, input *UpdateGroupInput) (*Group, error) {
 	group, err := s.groupRepo.GetByID(ctx, id)
 	if err != nil {
@@ -602,6 +639,23 @@ func (s *adminServiceImpl) UpdateGroup(ctx context.Context, id int64, input *Upd
 		group.ImagePrice4K = normalizePrice(input.ImagePrice4K)
 	}
 
+	// Claude Code 客户端限制
+	if input.ClaudeCodeOnly != nil {
+		group.ClaudeCodeOnly = *input.ClaudeCodeOnly
+	}
+	if input.FallbackGroupID != nil {
+		// 校验降级分组
+		if *input.FallbackGroupID > 0 {
+			if err := s.validateFallbackGroup(ctx, id, *input.FallbackGroupID); err != nil {
+				return nil, err
+			}
+			group.FallbackGroupID = input.FallbackGroupID
+		} else {
+			// 传入 0 或负数表示清除降级分组
+			group.FallbackGroupID = nil
+		}
+	}
+
 	if err := s.groupRepo.Update(ctx, group); err != nil {
 		return nil, err
 	}
@@ -950,6 +1004,15 @@ func (s *adminServiceImpl) ListProxies(ctx context.Context, page, pageSize int,
 	return proxies, result.Total, nil
 }
 
+func (s *adminServiceImpl) ListProxiesWithAccountCount(ctx context.Context, page, pageSize int, protocol, status, search string) ([]ProxyWithAccountCount, int64, error) {
+	params := pagination.PaginationParams{Page: page, PageSize: pageSize}
+	proxies, result, err := s.proxyRepo.ListWithFiltersAndAccountCount(ctx, params, protocol, status, search)
+	if err != nil {
+		return nil, 0, err
+	}
+	return proxies, result.Total, nil
+}
+
 func (s *adminServiceImpl) GetAllProxies(ctx context.Context) ([]Proxy, error) {
 	return s.proxyRepo.ListActive(ctx)
 }

backend/internal/service/admin_service_delete_test.go

@@ -186,6 +186,10 @@ func (s *proxyRepoStub) ListActiveWithAccountCount(ctx context.Context) ([]Proxy
 	panic("unexpected ListActiveWithAccountCount call")
 }
 
+func (s *proxyRepoStub) ListWithFiltersAndAccountCount(ctx context.Context, params pagination.PaginationParams, protocol, status, search string) ([]ProxyWithAccountCount, *pagination.PaginationResult, error) {
+	panic("unexpected ListWithFiltersAndAccountCount call")
+}
+
 func (s *proxyRepoStub) ExistsByHostPortAuth(ctx context.Context, host string, port int, username, password string) (bool, error) {
 	panic("unexpected ExistsByHostPortAuth call")
 }

backend/internal/service/antigravity_gateway_service.go

@@ -10,6 +10,7 @@ import (
 	"io"
 	"log"
 	mathrand "math/rand"
+	"net"
 	"net/http"
 	"strings"
 	"sync/atomic"
@@ -27,6 +28,32 @@ const (
 	antigravityRetryMaxDelay    = 16 * time.Second
 )
 
+// isAntigravityConnectionError 判断是否为连接错误（网络超时、DNS 失败、连接拒绝）
+func isAntigravityConnectionError(err error) bool {
+	if err == nil {
+		return false
+	}
+
+	// 检查超时错误
+	var netErr net.Error
+	if errors.As(err, &netErr) && netErr.Timeout() {
+		return true
+	}
+
+	// 检查连接错误（DNS 失败、连接拒绝）
+	var opErr *net.OpError
+	return errors.As(err, &opErr)
+}
+
+// shouldAntigravityFallbackToNextURL 判断是否应切换到下一个 URL
+// 仅连接错误和 HTTP 429 触发 URL 降级
+func shouldAntigravityFallbackToNextURL(err error, statusCode int) bool {
+	if isAntigravityConnectionError(err) {
+		return true
+	}
+	return statusCode == http.StatusTooManyRequests
+}
+
 // getSessionID 从 gin.Context 获取 session_id（用于日志追踪）
 func getSessionID(c *gin.Context) string {
 	if c == nil {
@@ -181,45 +208,70 @@ func (s *AntigravityGatewayService) TestConnection(ctx context.Context, account
 		return nil, fmt.Errorf("构建请求失败: %w", err)
 	}
 
-	// 构建 HTTP 请求（总是使用流式 endpoint，与官方客户端一致）
-	req, err := antigravity.NewAPIRequest(ctx, "streamGenerateContent", accessToken, requestBody)
-	if err != nil {
-		return nil, err
-	}
-
-	// 调试日志：Test 请求信息
-	log.Printf("[antigravity-Test] account=%s request_size=%d url=%s", account.Name, len(requestBody), req.URL.String())
-
 	// 代理 URL
 	proxyURL := ""
 	if account.ProxyID != nil && account.Proxy != nil {
 		proxyURL = account.Proxy.URL()
 	}
 
-	// 发送请求
-	resp, err := s.httpUpstream.Do(req, proxyURL, account.ID, account.Concurrency)
-	if err != nil {
-		return nil, fmt.Errorf("请求失败: %w", err)
-	}
-	defer func() { _ = resp.Body.Close() }()
-
-	// 读取响应
-	respBody, err := io.ReadAll(io.LimitReader(resp.Body, 2<<20))
-	if err != nil {
-		return nil, fmt.Errorf("读取响应失败: %w", err)
+	// URL fallback 循环
+	availableURLs := antigravity.DefaultURLAvailability.GetAvailableURLs()
+	if len(availableURLs) == 0 {
+		availableURLs = antigravity.BaseURLs // 所有 URL 都不可用时，重试所有
 	}
 
-	if resp.StatusCode >= 400 {
-		return nil, fmt.Errorf("API 返回 %d: %s", resp.StatusCode, string(respBody))
+	var lastErr error
+	for urlIdx, baseURL := range availableURLs {
+		// 构建 HTTP 请求（总是使用流式 endpoint，与官方客户端一致）
+		req, err := antigravity.NewAPIRequestWithURL(ctx, baseURL, "streamGenerateContent", accessToken, requestBody)
+		if err != nil {
+			lastErr = err
+			continue
+		}
+
+		// 调试日志：Test 请求信息
+		log.Printf("[antigravity-Test] account=%s request_size=%d url=%s", account.Name, len(requestBody), req.URL.String())
+
+		// 发送请求
+		resp, err := s.httpUpstream.Do(req, proxyURL, account.ID, account.Concurrency)
+		if err != nil {
+			lastErr = fmt.Errorf("请求失败: %w", err)
+			if shouldAntigravityFallbackToNextURL(err, 0) && urlIdx < len(availableURLs)-1 {
+				antigravity.DefaultURLAvailability.MarkUnavailable(baseURL)
+				log.Printf("[antigravity-Test] URL fallback: %s -> %s", baseURL, availableURLs[urlIdx+1])
+				continue
+			}
+			return nil, lastErr
+		}
+
+		// 读取响应
+		respBody, err := io.ReadAll(io.LimitReader(resp.Body, 2<<20))
+		_ = resp.Body.Close() // 立即关闭，避免循环内 defer 导致的资源泄漏
+		if err != nil {
+			return nil, fmt.Errorf("读取响应失败: %w", err)
+		}
+
+		// 检查是否需要 URL 降级
+		if shouldAntigravityFallbackToNextURL(nil, resp.StatusCode) && urlIdx < len(availableURLs)-1 {
+			antigravity.DefaultURLAvailability.MarkUnavailable(baseURL)
+			log.Printf("[antigravity-Test] URL fallback (HTTP %d): %s -> %s", resp.StatusCode, baseURL, availableURLs[urlIdx+1])
+			continue
+		}
+
+		if resp.StatusCode >= 400 {
+			return nil, fmt.Errorf("API 返回 %d: %s", resp.StatusCode, string(respBody))
+		}
+
+		// 解析流式响应，提取文本
+		text := extractTextFromSSEResponse(respBody)
+
+		return &TestConnectionResult{
+			Text:        text,
+			MappedModel: mappedModel,
+		}, nil
 	}
 
-	// 解析流式响应，提取文本
-	text := extractTextFromSSEResponse(respBody)
-
-	return &TestConnectionResult{
-		Text:        text,
-		MappedModel: mappedModel,
-	}, nil
+	return nil, lastErr
 }
 
 // buildGeminiTestRequest 构建 Gemini 格式测试请求
@@ -484,62 +536,86 @@ func (s *AntigravityGatewayService) Forward(ctx context.Context, c *gin.Context,
 	// 如果客户端请求非流式，在响应处理阶段会收集完整流式响应后转换返回
 	action := "streamGenerateContent"
 
+	// URL fallback 循环
+	availableURLs := antigravity.DefaultURLAvailability.GetAvailableURLs()
+	if len(availableURLs) == 0 {
+		availableURLs = antigravity.BaseURLs // 所有 URL 都不可用时，重试所有
+	}
+
 	// 重试循环
 	var resp *http.Response
-	for attempt := 1; attempt <= antigravityMaxRetries; attempt++ {
-		// 检查 context 是否已取消（客户端断开连接）
-		select {
-		case <-ctx.Done():
-			log.Printf("%s status=context_canceled error=%v", prefix, ctx.Err())
-			return nil, ctx.Err()
-		default:
-		}
+urlFallbackLoop:
+	for urlIdx, baseURL := range availableURLs {
+		for attempt := 1; attempt <= antigravityMaxRetries; attempt++ {
+			// 检查 context 是否已取消（客户端断开连接）
+			select {
+			case <-ctx.Done():
+				log.Printf("%s status=context_canceled error=%v", prefix, ctx.Err())
+				return nil, ctx.Err()
+			default:
+			}
 
-		upstreamReq, err := antigravity.NewAPIRequest(ctx, action, accessToken, geminiBody)
-		if err != nil {
-			return nil, err
-		}
+			upstreamReq, err := antigravity.NewAPIRequestWithURL(ctx, baseURL, action, accessToken, geminiBody)
+			if err != nil {
+				return nil, err
+			}
 
-		resp, err = s.httpUpstream.Do(upstreamReq, proxyURL, account.ID, account.Concurrency)
-		if err != nil {
-			if attempt < antigravityMaxRetries {
-				log.Printf("%s status=request_failed retry=%d/%d error=%v", prefix, attempt, antigravityMaxRetries, err)
-				if !sleepAntigravityBackoffWithContext(ctx, attempt) {
-					log.Printf("%s status=context_canceled_during_backoff", prefix)
-					return nil, ctx.Err()
+			resp, err = s.httpUpstream.Do(upstreamReq, proxyURL, account.ID, account.Concurrency)
+			if err != nil {
+				// 检查是否应触发 URL 降级
+				if shouldAntigravityFallbackToNextURL(err, 0) && urlIdx < len(availableURLs)-1 {
+					antigravity.DefaultURLAvailability.MarkUnavailable(baseURL)
+					log.Printf("%s URL fallback (connection error): %s -> %s", prefix, baseURL, availableURLs[urlIdx+1])
+					continue urlFallbackLoop
 				}
-				continue
-			}
-			log.Printf("%s status=request_failed retries_exhausted error=%v", prefix, err)
-			return nil, s.writeClaudeError(c, http.StatusBadGateway, "upstream_error", "Upstream request failed after retries")
-		}
-
-		if resp.StatusCode >= 400 && s.shouldRetryUpstreamError(resp.StatusCode) {
-			respBody, _ := io.ReadAll(io.LimitReader(resp.Body, 2<<20))
-			_ = resp.Body.Close()
-
-			if attempt < antigravityMaxRetries {
-				log.Printf("%s status=%d retry=%d/%d body=%s", prefix, resp.StatusCode, attempt, antigravityMaxRetries, truncateForLog(respBody, 500))
-				if !sleepAntigravityBackoffWithContext(ctx, attempt) {
-					log.Printf("%s status=context_canceled_during_backoff", prefix)
-					return nil, ctx.Err()
+				if attempt < antigravityMaxRetries {
+					log.Printf("%s status=request_failed retry=%d/%d error=%v", prefix, attempt, antigravityMaxRetries, err)
+					if !sleepAntigravityBackoffWithContext(ctx, attempt) {
+						log.Printf("%s status=context_canceled_during_backoff", prefix)
+						return nil, ctx.Err()
+					}
+					continue
 				}
-				continue
+				log.Printf("%s status=request_failed retries_exhausted error=%v", prefix, err)
+				return nil, s.writeClaudeError(c, http.StatusBadGateway, "upstream_error", "Upstream request failed after retries")
 			}
-			// 所有重试都失败，标记限流状态
-			if resp.StatusCode == 429 {
-				s.handleUpstreamError(ctx, prefix, account, resp.StatusCode, resp.Header, respBody)
-			}
-			// 最后一次尝试也失败
-			resp = &http.Response{
-				StatusCode: resp.StatusCode,
-				Header:     resp.Header.Clone(),
-				Body:       io.NopCloser(bytes.NewReader(respBody)),
-			}
-			break
-		}
 
-		break
+			// 检查是否应触发 URL 降级（仅 429）
+			if resp.StatusCode == http.StatusTooManyRequests && urlIdx < len(availableURLs)-1 {
+				respBody, _ := io.ReadAll(io.LimitReader(resp.Body, 2<<20))
+				_ = resp.Body.Close()
+				antigravity.DefaultURLAvailability.MarkUnavailable(baseURL)
+				log.Printf("%s URL fallback (HTTP 429): %s -> %s body=%s", prefix, baseURL, availableURLs[urlIdx+1], truncateForLog(respBody, 200))
+				continue urlFallbackLoop
+			}
+
+			if resp.StatusCode >= 400 && s.shouldRetryUpstreamError(resp.StatusCode) {
+				respBody, _ := io.ReadAll(io.LimitReader(resp.Body, 2<<20))
+				_ = resp.Body.Close()
+
+				if attempt < antigravityMaxRetries {
+					log.Printf("%s status=%d retry=%d/%d body=%s", prefix, resp.StatusCode, attempt, antigravityMaxRetries, truncateForLog(respBody, 500))
+					if !sleepAntigravityBackoffWithContext(ctx, attempt) {
+						log.Printf("%s status=context_canceled_during_backoff", prefix)
+						return nil, ctx.Err()
+					}
+					continue
+				}
+				// 所有重试都失败，标记限流状态
+				if resp.StatusCode == 429 {
+					s.handleUpstreamError(ctx, prefix, account, resp.StatusCode, resp.Header, respBody)
+				}
+				// 最后一次尝试也失败
+				resp = &http.Response{
+					StatusCode: resp.StatusCode,
+					Header:     resp.Header.Clone(),
+					Body:       io.NopCloser(bytes.NewReader(respBody)),
+				}
+				break urlFallbackLoop
+			}
+
+			break urlFallbackLoop
+		}
 	}
 	defer func() { _ = resp.Body.Close() }()
 
@@ -1003,61 +1079,85 @@ func (s *AntigravityGatewayService) ForwardGemini(ctx context.Context, c *gin.Co
 	// 如果客户端请求非流式，在响应处理阶段会收集完整流式响应后返回
 	upstreamAction := "streamGenerateContent"
 
+	// URL fallback 循环
+	availableURLs := antigravity.DefaultURLAvailability.GetAvailableURLs()
+	if len(availableURLs) == 0 {
+		availableURLs = antigravity.BaseURLs // 所有 URL 都不可用时，重试所有
+	}
+
 	// 重试循环
 	var resp *http.Response
-	for attempt := 1; attempt <= antigravityMaxRetries; attempt++ {
-		// 检查 context 是否已取消（客户端断开连接）
-		select {
-		case <-ctx.Done():
-			log.Printf("%s status=context_canceled error=%v", prefix, ctx.Err())
-			return nil, ctx.Err()
-		default:
-		}
+urlFallbackLoop:
+	for urlIdx, baseURL := range availableURLs {
+		for attempt := 1; attempt <= antigravityMaxRetries; attempt++ {
+			// 检查 context 是否已取消（客户端断开连接）
+			select {
+			case <-ctx.Done():
+				log.Printf("%s status=context_canceled error=%v", prefix, ctx.Err())
+				return nil, ctx.Err()
+			default:
+			}
 
-		upstreamReq, err := antigravity.NewAPIRequest(ctx, upstreamAction, accessToken, wrappedBody)
-		if err != nil {
-			return nil, err
-		}
+			upstreamReq, err := antigravity.NewAPIRequestWithURL(ctx, baseURL, upstreamAction, accessToken, wrappedBody)
+			if err != nil {
+				return nil, err
+			}
 
-		resp, err = s.httpUpstream.Do(upstreamReq, proxyURL, account.ID, account.Concurrency)
-		if err != nil {
-			if attempt < antigravityMaxRetries {
-				log.Printf("%s status=request_failed retry=%d/%d error=%v", prefix, attempt, antigravityMaxRetries, err)
-				if !sleepAntigravityBackoffWithContext(ctx, attempt) {
-					log.Printf("%s status=context_canceled_during_backoff", prefix)
-					return nil, ctx.Err()
+			resp, err = s.httpUpstream.Do(upstreamReq, proxyURL, account.ID, account.Concurrency)
+			if err != nil {
+				// 检查是否应触发 URL 降级
+				if shouldAntigravityFallbackToNextURL(err, 0) && urlIdx < len(availableURLs)-1 {
+					antigravity.DefaultURLAvailability.MarkUnavailable(baseURL)
+					log.Printf("%s URL fallback (connection error): %s -> %s", prefix, baseURL, availableURLs[urlIdx+1])
+					continue urlFallbackLoop
 				}
-				continue
-			}
-			log.Printf("%s status=request_failed retries_exhausted error=%v", prefix, err)
-			return nil, s.writeGoogleError(c, http.StatusBadGateway, "Upstream request failed after retries")
-		}
-
-		if resp.StatusCode >= 400 && s.shouldRetryUpstreamError(resp.StatusCode) {
-			respBody, _ := io.ReadAll(io.LimitReader(resp.Body, 2<<20))
-			_ = resp.Body.Close()
-
-			if attempt < antigravityMaxRetries {
-				log.Printf("%s status=%d retry=%d/%d", prefix, resp.StatusCode, attempt, antigravityMaxRetries)
-				if !sleepAntigravityBackoffWithContext(ctx, attempt) {
-					log.Printf("%s status=context_canceled_during_backoff", prefix)
-					return nil, ctx.Err()
+				if attempt < antigravityMaxRetries {
+					log.Printf("%s status=request_failed retry=%d/%d error=%v", prefix, attempt, antigravityMaxRetries, err)
+					if !sleepAntigravityBackoffWithContext(ctx, attempt) {
+						log.Printf("%s status=context_canceled_during_backoff", prefix)
+						return nil, ctx.Err()
+					}
+					continue
 				}
-				continue
+				log.Printf("%s status=request_failed retries_exhausted error=%v", prefix, err)
+				return nil, s.writeGoogleError(c, http.StatusBadGateway, "Upstream request failed after retries")
 			}
-			// 所有重试都失败，标记限流状态
-			if resp.StatusCode == 429 {
-				s.handleUpstreamError(ctx, prefix, account, resp.StatusCode, resp.Header, respBody)
-			}
-			resp = &http.Response{
-				StatusCode: resp.StatusCode,
-				Header:     resp.Header.Clone(),
-				Body:       io.NopCloser(bytes.NewReader(respBody)),
-			}
-			break
-		}
 
-		break
+			// 检查是否应触发 URL 降级（仅 429）
+			if resp.StatusCode == http.StatusTooManyRequests && urlIdx < len(availableURLs)-1 {
+				respBody, _ := io.ReadAll(io.LimitReader(resp.Body, 2<<20))
+				_ = resp.Body.Close()
+				antigravity.DefaultURLAvailability.MarkUnavailable(baseURL)
+				log.Printf("%s URL fallback (HTTP 429): %s -> %s body=%s", prefix, baseURL, availableURLs[urlIdx+1], truncateForLog(respBody, 200))
+				continue urlFallbackLoop
+			}
+
+			if resp.StatusCode >= 400 && s.shouldRetryUpstreamError(resp.StatusCode) {
+				respBody, _ := io.ReadAll(io.LimitReader(resp.Body, 2<<20))
+				_ = resp.Body.Close()
+
+				if attempt < antigravityMaxRetries {
+					log.Printf("%s status=%d retry=%d/%d", prefix, resp.StatusCode, attempt, antigravityMaxRetries)
+					if !sleepAntigravityBackoffWithContext(ctx, attempt) {
+						log.Printf("%s status=context_canceled_during_backoff", prefix)
+						return nil, ctx.Err()
+					}
+					continue
+				}
+				// 所有重试都失败，标记限流状态
+				if resp.StatusCode == 429 {
+					s.handleUpstreamError(ctx, prefix, account, resp.StatusCode, resp.Header, respBody)
+				}
+				resp = &http.Response{
+					StatusCode: resp.StatusCode,
+					Header:     resp.Header.Clone(),
+					Body:       io.NopCloser(bytes.NewReader(respBody)),
+				}
+				break urlFallbackLoop
+			}
+
+			break urlFallbackLoop
+		}
 	}
 	defer func() {
 		if resp != nil && resp.Body != nil {

backend/internal/service/auth_service.go

@@ -82,14 +82,18 @@ func (s *AuthService) RegisterWithVerification(ctx context.Context, email, passw
 
 	// 检查是否需要邮件验证
 	if s.settingService != nil && s.settingService.IsEmailVerifyEnabled(ctx) {
+		// 如果邮件验证已开启但邮件服务未配置，拒绝注册
+		// 这是一个配置错误，不应该允许绕过验证
+		if s.emailService == nil {
+			log.Println("[Auth] Email verification enabled but email service not configured, rejecting registration")
+			return "", nil, ErrServiceUnavailable
+		}
 		if verifyCode == "" {
 			return "", nil, ErrEmailVerifyRequired
 		}
 		// 验证邮箱验证码
-		if s.emailService != nil {
-			if err := s.emailService.VerifyCode(ctx, email, verifyCode); err != nil {
-				return "", nil, fmt.Errorf("verify code: %w", err)
-			}
+		if err := s.emailService.VerifyCode(ctx, email, verifyCode); err != nil {
+			return "", nil, fmt.Errorf("verify code: %w", err)
 		}
 	}
 
@@ -336,6 +340,11 @@ func (s *AuthService) ValidateToken(tokenString string) (*JWTClaims, error) {
 
 	if err != nil {
 		if errors.Is(err, jwt.ErrTokenExpired) {
+			// token 过期但仍返回 claims（用于 RefreshToken 等场景）
+			// jwt-go 在解析时即使遇到过期错误，token.Claims 仍会被填充
+			if claims, ok := token.Claims.(*JWTClaims); ok {
+				return claims, ErrTokenExpired
+			}
 			return nil, ErrTokenExpired
 		}
 		return nil, ErrInvalidToken

backend/internal/service/auth_service_register_test.go

@@ -113,13 +113,27 @@ func TestAuthService_Register_Disabled(t *testing.T) {
 	require.ErrorIs(t, err, ErrRegDisabled)
 }
 
-func TestAuthService_Register_EmailVerifyRequired(t *testing.T) {
+func TestAuthService_Register_EmailVerifyEnabledButServiceNotConfigured(t *testing.T) {
 	repo := &userRepoStub{}
+	// 邮件验证开启但 emailCache 为 nil（emailService 未配置）
 	service := newAuthService(repo, map[string]string{
 		SettingKeyRegistrationEnabled: "true",
 		SettingKeyEmailVerifyEnabled:  "true",
 	}, nil)
 
+	// 应返回服务不可用错误，而不是允许绕过验证
+	_, _, err := service.RegisterWithVerification(context.Background(), "user@test.com", "password", "any-code")
+	require.ErrorIs(t, err, ErrServiceUnavailable)
+}
+
+func TestAuthService_Register_EmailVerifyRequired(t *testing.T) {
+	repo := &userRepoStub{}
+	cache := &emailCacheStub{} // 配置 emailService
+	service := newAuthService(repo, map[string]string{
+		SettingKeyRegistrationEnabled: "true",
+		SettingKeyEmailVerifyEnabled:  "true",
+	}, cache)
+
 	_, _, err := service.RegisterWithVerification(context.Background(), "user@test.com", "password", "")
 	require.ErrorIs(t, err, ErrEmailVerifyRequired)
 }
@@ -180,3 +194,63 @@ func TestAuthService_Register_Success(t *testing.T) {
 	require.Len(t, repo.created, 1)
 	require.True(t, user.CheckPassword("password"))
 }
+
+func TestAuthService_ValidateToken_ExpiredReturnsClaimsWithError(t *testing.T) {
+	repo := &userRepoStub{}
+	service := newAuthService(repo, nil, nil)
+
+	// 创建用户并生成 token
+	user := &User{
+		ID:           1,
+		Email:        "test@test.com",
+		Role:         RoleUser,
+		Status:       StatusActive,
+		TokenVersion: 1,
+	}
+	token, err := service.GenerateToken(user)
+	require.NoError(t, err)
+
+	// 验证有效 token
+	claims, err := service.ValidateToken(token)
+	require.NoError(t, err)
+	require.NotNil(t, claims)
+	require.Equal(t, int64(1), claims.UserID)
+
+	// 模拟过期 token（通过创建一个过期很久的 token）
+	service.cfg.JWT.ExpireHour = -1 // 设置为负数使 token 立即过期
+	expiredToken, err := service.GenerateToken(user)
+	require.NoError(t, err)
+	service.cfg.JWT.ExpireHour = 1 // 恢复
+
+	// 验证过期 token 应返回 claims 和 ErrTokenExpired
+	claims, err = service.ValidateToken(expiredToken)
+	require.ErrorIs(t, err, ErrTokenExpired)
+	require.NotNil(t, claims, "claims should not be nil when token is expired")
+	require.Equal(t, int64(1), claims.UserID)
+	require.Equal(t, "test@test.com", claims.Email)
+}
+
+func TestAuthService_RefreshToken_ExpiredTokenNoPanic(t *testing.T) {
+	user := &User{
+		ID:           1,
+		Email:        "test@test.com",
+		Role:         RoleUser,
+		Status:       StatusActive,
+		TokenVersion: 1,
+	}
+	repo := &userRepoStub{user: user}
+	service := newAuthService(repo, nil, nil)
+
+	// 创建过期 token
+	service.cfg.JWT.ExpireHour = -1
+	expiredToken, err := service.GenerateToken(user)
+	require.NoError(t, err)
+	service.cfg.JWT.ExpireHour = 1
+
+	// RefreshToken 使用过期 token 不应 panic
+	require.NotPanics(t, func() {
+		newToken, err := service.RefreshToken(context.Background(), expiredToken)
+		require.NoError(t, err)
+		require.NotEmpty(t, newToken)
+	})
+}

backend/internal/service/claude_code_validator.go

@@ -0,0 +1,265 @@
+package service
+
+import (
+	"context"
+	"net/http"
+	"regexp"
+	"strings"
+
+	"github.com/Wei-Shaw/sub2api/internal/pkg/ctxkey"
+)
+
+// ClaudeCodeValidator 验证请求是否来自 Claude Code 客户端
+// 完全学习自 claude-relay-service 项目的验证逻辑
+type ClaudeCodeValidator struct{}
+
+var (
+	// User-Agent 匹配: claude-cli/x.x.x (仅支持官方 CLI，大小写不敏感)
+	claudeCodeUAPattern = regexp.MustCompile(`(?i)^claude-cli/\d+\.\d+\.\d+`)
+
+	// metadata.user_id 格式: user_{64位hex}_account__session_{uuid}
+	userIDPattern = regexp.MustCompile(`^user_[a-fA-F0-9]{64}_account__session_[\w-]+$`)
+
+	// System prompt 相似度阈值（默认 0.5，和 claude-relay-service 一致）
+	systemPromptThreshold = 0.5
+)
+
+// Claude Code 官方 System Prompt 模板
+// 从 claude-relay-service/src/utils/contents.js 提取
+var claudeCodeSystemPrompts = []string{
+	// claudeOtherSystemPrompt1 - Primary
+	"You are Claude Code, Anthropic's official CLI for Claude.",
+
+	// claudeOtherSystemPrompt3 - Agent SDK
+	"You are a Claude agent, built on Anthropic's Claude Agent SDK.",
+
+	// claudeOtherSystemPrompt4 - Compact Agent SDK
+	"You are Claude Code, Anthropic's official CLI for Claude, running within the Claude Agent SDK.",
+
+	// exploreAgentSystemPrompt
+	"You are a file search specialist for Claude Code, Anthropic's official CLI for Claude.",
+
+	// claudeOtherSystemPromptCompact - Compact (用于对话摘要)
+	"You are a helpful AI assistant tasked with summarizing conversations.",
+
+	// claudeOtherSystemPrompt2 - Secondary (长提示词的关键部分)
+	"You are an interactive CLI tool that helps users",
+}
+
+// NewClaudeCodeValidator 创建验证器实例
+func NewClaudeCodeValidator() *ClaudeCodeValidator {
+	return &ClaudeCodeValidator{}
+}
+
+// Validate 验证请求是否来自 Claude Code CLI
+// 采用与 claude-relay-service 完全一致的验证策略：
+//
+//	Step 1: User-Agent 检查 (必需) - 必须是 claude-cli/x.x.x
+//	Step 2: 对于非 messages 路径，只要 UA 匹配就通过
+//	Step 3: 对于 messages 路径，进行严格验证：
+//	        - System prompt 相似度检查
+//	        - X-App header 检查
+//	        - anthropic-beta header 检查
+//	        - anthropic-version header 检查
+//	        - metadata.user_id 格式验证
+func (v *ClaudeCodeValidator) Validate(r *http.Request, body map[string]any) bool {
+	// Step 1: User-Agent 检查
+	ua := r.Header.Get("User-Agent")
+	if !claudeCodeUAPattern.MatchString(ua) {
+		return false
+	}
+
+	// Step 2: 非 messages 路径，只要 UA 匹配就通过
+	path := r.URL.Path
+	if !strings.Contains(path, "messages") {
+		return true
+	}
+
+	// Step 3: messages 路径，进行严格验证
+
+	// 3.1 检查 system prompt 相似度
+	if !v.hasClaudeCodeSystemPrompt(body) {
+		return false
+	}
+
+	// 3.2 检查必需的 headers（值不为空即可）
+	xApp := r.Header.Get("X-App")
+	if xApp == "" {
+		return false
+	}
+
+	anthropicBeta := r.Header.Get("anthropic-beta")
+	if anthropicBeta == "" {
+		return false
+	}
+
+	anthropicVersion := r.Header.Get("anthropic-version")
+	if anthropicVersion == "" {
+		return false
+	}
+
+	// 3.3 验证 metadata.user_id
+	if body == nil {
+		return false
+	}
+
+	metadata, ok := body["metadata"].(map[string]any)
+	if !ok {
+		return false
+	}
+
+	userID, ok := metadata["user_id"].(string)
+	if !ok || userID == "" {
+		return false
+	}
+
+	if !userIDPattern.MatchString(userID) {
+		return false
+	}
+
+	return true
+}
+
+// hasClaudeCodeSystemPrompt 检查请求是否包含 Claude Code 系统提示词
+// 使用字符串相似度匹配（Dice coefficient）
+func (v *ClaudeCodeValidator) hasClaudeCodeSystemPrompt(body map[string]any) bool {
+	if body == nil {
+		return false
+	}
+
+	// 检查 model 字段
+	if _, ok := body["model"].(string); !ok {
+		return false
+	}
+
+	// 获取 system 字段
+	systemEntries, ok := body["system"].([]any)
+	if !ok {
+		return false
+	}
+
+	// 检查每个 system entry
+	for _, entry := range systemEntries {
+		entryMap, ok := entry.(map[string]any)
+		if !ok {
+			continue
+		}
+
+		text, ok := entryMap["text"].(string)
+		if !ok || text == "" {
+			continue
+		}
+
+		// 计算与所有模板的最佳相似度
+		bestScore := v.bestSimilarityScore(text)
+		if bestScore >= systemPromptThreshold {
+			return true
+		}
+	}
+
+	return false
+}
+
+// bestSimilarityScore 计算文本与所有 Claude Code 模板的最佳相似度
+func (v *ClaudeCodeValidator) bestSimilarityScore(text string) float64 {
+	normalizedText := normalizePrompt(text)
+	bestScore := 0.0
+
+	for _, template := range claudeCodeSystemPrompts {
+		normalizedTemplate := normalizePrompt(template)
+		score := diceCoefficient(normalizedText, normalizedTemplate)
+		if score > bestScore {
+			bestScore = score
+		}
+	}
+
+	return bestScore
+}
+
+// normalizePrompt 标准化提示词文本（去除多余空白）
+func normalizePrompt(text string) string {
+	// 将所有空白字符替换为单个空格，并去除首尾空白
+	return strings.Join(strings.Fields(text), " ")
+}
+
+// diceCoefficient 计算两个字符串的 Dice 系数（Sørensen–Dice coefficient）
+// 这是 string-similarity 库使用的算法
+// 公式: 2 * |intersection| / (|bigrams(a)| + |bigrams(b)|)
+func diceCoefficient(a, b string) float64 {
+	if a == b {
+		return 1.0
+	}
+
+	if len(a) < 2 || len(b) < 2 {
+		return 0.0
+	}
+
+	// 生成 bigrams
+	bigramsA := getBigrams(a)
+	bigramsB := getBigrams(b)
+
+	if len(bigramsA) == 0 || len(bigramsB) == 0 {
+		return 0.0
+	}
+
+	// 计算交集大小
+	intersection := 0
+	for bigram, countA := range bigramsA {
+		if countB, exists := bigramsB[bigram]; exists {
+			if countA < countB {
+				intersection += countA
+			} else {
+				intersection += countB
+			}
+		}
+	}
+
+	// 计算总 bigram 数量
+	totalA := 0
+	for _, count := range bigramsA {
+		totalA += count
+	}
+	totalB := 0
+	for _, count := range bigramsB {
+		totalB += count
+	}
+
+	return float64(2*intersection) / float64(totalA+totalB)
+}
+
+// getBigrams 获取字符串的所有 bigrams（相邻字符对）
+func getBigrams(s string) map[string]int {
+	bigrams := make(map[string]int)
+	runes := []rune(strings.ToLower(s))
+
+	for i := 0; i < len(runes)-1; i++ {
+		bigram := string(runes[i : i+2])
+		bigrams[bigram]++
+	}
+
+	return bigrams
+}
+
+// ValidateUserAgent 仅验证 User-Agent（用于不需要解析请求体的场景）
+func (v *ClaudeCodeValidator) ValidateUserAgent(ua string) bool {
+	return claudeCodeUAPattern.MatchString(ua)
+}
+
+// IncludesClaudeCodeSystemPrompt 检查请求体是否包含 Claude Code 系统提示词
+// 只要存在匹配的系统提示词就返回 true（用于宽松检测）
+func (v *ClaudeCodeValidator) IncludesClaudeCodeSystemPrompt(body map[string]any) bool {
+	return v.hasClaudeCodeSystemPrompt(body)
+}
+
+// IsClaudeCodeClient 从 context 中获取 Claude Code 客户端标识
+func IsClaudeCodeClient(ctx context.Context) bool {
+	if v, ok := ctx.Value(ctxkey.IsClaudeCodeClient).(bool); ok {
+		return v
+	}
+	return false
+}
+
+// SetClaudeCodeClient 将 Claude Code 客户端标识设置到 context 中
+func SetClaudeCodeClient(ctx context.Context, isClaudeCode bool) context.Context {
+	return context.WithValue(ctx, ctxkey.IsClaudeCodeClient, isClaudeCode)
+}

backend/internal/service/gateway_multiplatform_test.go

@@ -166,14 +166,14 @@ type mockGatewayCacheForPlatform struct {
 	sessionBindings map[string]int64
 }
 
-func (m *mockGatewayCacheForPlatform) GetSessionAccountID(ctx context.Context, sessionHash string) (int64, error) {
+func (m *mockGatewayCacheForPlatform) GetSessionAccountID(ctx context.Context, groupID int64, sessionHash string) (int64, error) {
 	if id, ok := m.sessionBindings[sessionHash]; ok {
 		return id, nil
 	}
 	return 0, errors.New("not found")
 }
 
-func (m *mockGatewayCacheForPlatform) SetSessionAccountID(ctx context.Context, sessionHash string, accountID int64, ttl time.Duration) error {
+func (m *mockGatewayCacheForPlatform) SetSessionAccountID(ctx context.Context, groupID int64, sessionHash string, accountID int64, ttl time.Duration) error {
 	if m.sessionBindings == nil {
 		m.sessionBindings = make(map[string]int64)
 	}
@@ -181,7 +181,7 @@ func (m *mockGatewayCacheForPlatform) SetSessionAccountID(ctx context.Context, s
 	return nil
 }
 
-func (m *mockGatewayCacheForPlatform) RefreshSessionTTL(ctx context.Context, sessionHash string, ttl time.Duration) error {
+func (m *mockGatewayCacheForPlatform) RefreshSessionTTL(ctx context.Context, groupID int64, sessionHash string, ttl time.Duration) error {
 	return nil
 }
 

backend/internal/service/gateway_service.go

@@ -56,6 +56,9 @@ var (
 	}
 )
 
+// ErrClaudeCodeOnly 表示分组仅允许 Claude Code 客户端访问
+var ErrClaudeCodeOnly = errors.New("this group only allows Claude Code clients")
+
 // allowedHeaders 白名单headers（参考CRS项目）
 var allowedHeaders = map[string]bool{
 	"accept":                                    true,
@@ -80,9 +83,17 @@ var allowedHeaders = map[string]bool{
 
 // GatewayCache defines cache operations for gateway service
 type GatewayCache interface {
-	GetSessionAccountID(ctx context.Context, sessionHash string) (int64, error)
-	SetSessionAccountID(ctx context.Context, sessionHash string, accountID int64, ttl time.Duration) error
-	RefreshSessionTTL(ctx context.Context, sessionHash string, ttl time.Duration) error
+	GetSessionAccountID(ctx context.Context, groupID int64, sessionHash string) (int64, error)
+	SetSessionAccountID(ctx context.Context, groupID int64, sessionHash string, accountID int64, ttl time.Duration) error
+	RefreshSessionTTL(ctx context.Context, groupID int64, sessionHash string, ttl time.Duration) error
+}
+
+// derefGroupID safely dereferences *int64 to int64, returning 0 if nil
+func derefGroupID(groupID *int64) int64 {
+	if groupID == nil {
+		return 0
+	}
+	return *groupID
 }
 
 type AccountWaitPlan struct {
@@ -225,11 +236,11 @@ func (s *GatewayService) GenerateSessionHash(parsed *ParsedRequest) string {
 }
 
 // BindStickySession sets session -> account binding with standard TTL.
-func (s *GatewayService) BindStickySession(ctx context.Context, sessionHash string, accountID int64) error {
+func (s *GatewayService) BindStickySession(ctx context.Context, groupID *int64, sessionHash string, accountID int64) error {
 	if sessionHash == "" || accountID <= 0 || s.cache == nil {
 		return nil
 	}
-	return s.cache.SetSessionAccountID(ctx, sessionHash, accountID, stickySessionTTL)
+	return s.cache.SetSessionAccountID(ctx, derefGroupID(groupID), sessionHash, accountID, stickySessionTTL)
 }
 
 func (s *GatewayService) extractCacheableContent(parsed *ParsedRequest) string {
@@ -356,6 +367,21 @@ func (s *GatewayService) SelectAccountForModelWithExclusions(ctx context.Context
 			return nil, fmt.Errorf("get group failed: %w", err)
 		}
 		platform = group.Platform
+
+		// 检查 Claude Code 客户端限制
+		if group.ClaudeCodeOnly {
+			isClaudeCode := IsClaudeCodeClient(ctx)
+			if !isClaudeCode {
+				// 非 Claude Code 客户端，检查是否有降级分组
+				if group.FallbackGroupID != nil {
+					// 使用降级分组重新调度
+					fallbackGroupID := *group.FallbackGroupID
+					return s.SelectAccountForModelWithExclusions(ctx, &fallbackGroupID, sessionHash, requestedModel, excludedIDs)
+				}
+				// 无降级分组，拒绝访问
+				return nil, ErrClaudeCodeOnly
+			}
+		}
 	} else {
 		// 无分组时只使用原生 anthropic 平台
 		platform = PlatformAnthropic
@@ -377,10 +403,17 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 	cfg := s.schedulingConfig()
 	var stickyAccountID int64
 	if sessionHash != "" && s.cache != nil {
-		if accountID, err := s.cache.GetSessionAccountID(ctx, sessionHash); err == nil {
+		if accountID, err := s.cache.GetSessionAccountID(ctx, derefGroupID(groupID), sessionHash); err == nil {
 			stickyAccountID = accountID
 		}
 	}
+
+	// 检查 Claude Code 客户端限制（可能会替换 groupID 为降级分组）
+	groupID, err := s.checkClaudeCodeRestriction(ctx, groupID)
+	if err != nil {
+		return nil, err
+	}
+
 	if s.concurrencyService == nil || !cfg.LoadBatchEnabled {
 		account, err := s.SelectAccountForModelWithExclusions(ctx, groupID, sessionHash, requestedModel, excludedIDs)
 		if err != nil {
@@ -443,7 +476,7 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 
 	// ============ Layer 1: 粘性会话优先 ============
 	if sessionHash != "" && s.cache != nil {
-		accountID, err := s.cache.GetSessionAccountID(ctx, sessionHash)
+		accountID, err := s.cache.GetSessionAccountID(ctx, derefGroupID(groupID), sessionHash)
 		if err == nil && accountID > 0 && !isExcluded(accountID) {
 			account, err := s.accountRepo.GetByID(ctx, accountID)
 			if err == nil && s.isAccountInGroup(account, groupID) &&
@@ -452,7 +485,7 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 				(requestedModel == "" || s.isModelSupportedByAccount(account, requestedModel)) {
 				result, err := s.tryAcquireAccountSlot(ctx, accountID, account.Concurrency)
 				if err == nil && result.Acquired {
-					_ = s.cache.RefreshSessionTTL(ctx, sessionHash, stickySessionTTL)
+					_ = s.cache.RefreshSessionTTL(ctx, derefGroupID(groupID), sessionHash, stickySessionTTL)
 					return &AccountSelectionResult{
 						Account:     account,
 						Acquired:    true,
@@ -506,7 +539,7 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 
 	loadMap, err := s.concurrencyService.GetAccountsLoadBatch(ctx, accountLoads)
 	if err != nil {
-		if result, ok := s.tryAcquireByLegacyOrder(ctx, candidates, sessionHash, preferOAuth); ok {
+		if result, ok := s.tryAcquireByLegacyOrder(ctx, candidates, groupID, sessionHash, preferOAuth); ok {
 			return result, nil
 		}
 	} else {
@@ -556,7 +589,7 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 				result, err := s.tryAcquireAccountSlot(ctx, item.account.ID, item.account.Concurrency)
 				if err == nil && result.Acquired {
 					if sessionHash != "" && s.cache != nil {
-						_ = s.cache.SetSessionAccountID(ctx, sessionHash, item.account.ID, stickySessionTTL)
+						_ = s.cache.SetSessionAccountID(ctx, derefGroupID(groupID), sessionHash, item.account.ID, stickySessionTTL)
 					}
 					return &AccountSelectionResult{
 						Account:     item.account,
@@ -584,7 +617,7 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 	return nil, errors.New("no available accounts")
 }
 
-func (s *GatewayService) tryAcquireByLegacyOrder(ctx context.Context, candidates []*Account, sessionHash string, preferOAuth bool) (*AccountSelectionResult, bool) {
+func (s *GatewayService) tryAcquireByLegacyOrder(ctx context.Context, candidates []*Account, groupID *int64, sessionHash string, preferOAuth bool) (*AccountSelectionResult, bool) {
 	ordered := append([]*Account(nil), candidates...)
 	sortAccountsByPriorityAndLastUsed(ordered, preferOAuth)
 
@@ -592,7 +625,7 @@ func (s *GatewayService) tryAcquireByLegacyOrder(ctx context.Context, candidates
 		result, err := s.tryAcquireAccountSlot(ctx, acc.ID, acc.Concurrency)
 		if err == nil && result.Acquired {
 			if sessionHash != "" && s.cache != nil {
-				_ = s.cache.SetSessionAccountID(ctx, sessionHash, acc.ID, stickySessionTTL)
+				_ = s.cache.SetSessionAccountID(ctx, derefGroupID(groupID), sessionHash, acc.ID, stickySessionTTL)
 			}
 			return &AccountSelectionResult{
 				Account:     acc,
@@ -619,6 +652,42 @@ func (s *GatewayService) schedulingConfig() config.GatewaySchedulingConfig {
 	}
 }
 
+// checkClaudeCodeRestriction 检查分组的 Claude Code 客户端限制
+// 如果分组启用了 claude_code_only 且请求不是来自 Claude Code 客户端：
+//   - 有降级分组：返回降级分组的 ID
+//   - 无降级分组：返回 ErrClaudeCodeOnly 错误
+func (s *GatewayService) checkClaudeCodeRestriction(ctx context.Context, groupID *int64) (*int64, error) {
+	if groupID == nil {
+		return groupID, nil
+	}
+
+	// 强制平台模式不检查 Claude Code 限制
+	if _, hasForcePlatform := ctx.Value(ctxkey.ForcePlatform).(string); hasForcePlatform {
+		return groupID, nil
+	}
+
+	group, err := s.groupRepo.GetByID(ctx, *groupID)
+	if err != nil {
+		return nil, fmt.Errorf("get group failed: %w", err)
+	}
+
+	if !group.ClaudeCodeOnly {
+		return groupID, nil
+	}
+
+	// 分组启用了 Claude Code 限制
+	if IsClaudeCodeClient(ctx) {
+		return groupID, nil
+	}
+
+	// 非 Claude Code 客户端，检查降级分组
+	if group.FallbackGroupID != nil {
+		return group.FallbackGroupID, nil
+	}
+
+	return nil, ErrClaudeCodeOnly
+}
+
 func (s *GatewayService) resolvePlatform(ctx context.Context, groupID *int64) (string, bool, error) {
 	forcePlatform, hasForcePlatform := ctx.Value(ctxkey.ForcePlatform).(string)
 	if hasForcePlatform && forcePlatform != "" {
@@ -738,13 +807,13 @@ func (s *GatewayService) selectAccountForModelWithPlatform(ctx context.Context,
 	preferOAuth := platform == PlatformGemini
 	// 1. 查询粘性会话
 	if sessionHash != "" && s.cache != nil {
-		accountID, err := s.cache.GetSessionAccountID(ctx, sessionHash)
+		accountID, err := s.cache.GetSessionAccountID(ctx, derefGroupID(groupID), sessionHash)
 		if err == nil && accountID > 0 {
 			if _, excluded := excludedIDs[accountID]; !excluded {
 				account, err := s.accountRepo.GetByID(ctx, accountID)
 				// 检查账号分组归属和平台匹配（确保粘性会话不会跨分组或跨平台）
 				if err == nil && s.isAccountInGroup(account, groupID) && account.Platform == platform && account.IsSchedulable() && (requestedModel == "" || s.isModelSupportedByAccount(account, requestedModel)) {
-					if err := s.cache.RefreshSessionTTL(ctx, sessionHash, stickySessionTTL); err != nil {
+					if err := s.cache.RefreshSessionTTL(ctx, derefGroupID(groupID), sessionHash, stickySessionTTL); err != nil {
 						log.Printf("refresh session ttl failed: session=%s err=%v", sessionHash, err)
 					}
 					return account, nil
@@ -811,7 +880,7 @@ func (s *GatewayService) selectAccountForModelWithPlatform(ctx context.Context,
 
 	// 4. 建立粘性绑定
 	if sessionHash != "" && s.cache != nil {
-		if err := s.cache.SetSessionAccountID(ctx, sessionHash, selected.ID, stickySessionTTL); err != nil {
+		if err := s.cache.SetSessionAccountID(ctx, derefGroupID(groupID), sessionHash, selected.ID, stickySessionTTL); err != nil {
 			log.Printf("set session account failed: session=%s account_id=%d err=%v", sessionHash, selected.ID, err)
 		}
 	}
@@ -827,14 +896,14 @@ func (s *GatewayService) selectAccountWithMixedScheduling(ctx context.Context, g
 
 	// 1. 查询粘性会话
 	if sessionHash != "" && s.cache != nil {
-		accountID, err := s.cache.GetSessionAccountID(ctx, sessionHash)
+		accountID, err := s.cache.GetSessionAccountID(ctx, derefGroupID(groupID), sessionHash)
 		if err == nil && accountID > 0 {
 			if _, excluded := excludedIDs[accountID]; !excluded {
 				account, err := s.accountRepo.GetByID(ctx, accountID)
 				// 检查账号分组归属和有效性：原生平台直接匹配，antigravity 需要启用混合调度
 				if err == nil && s.isAccountInGroup(account, groupID) && account.IsSchedulable() && (requestedModel == "" || s.isModelSupportedByAccount(account, requestedModel)) {
 					if account.Platform == nativePlatform || (account.Platform == PlatformAntigravity && account.IsMixedSchedulingEnabled()) {
-						if err := s.cache.RefreshSessionTTL(ctx, sessionHash, stickySessionTTL); err != nil {
+						if err := s.cache.RefreshSessionTTL(ctx, derefGroupID(groupID), sessionHash, stickySessionTTL); err != nil {
 							log.Printf("refresh session ttl failed: session=%s err=%v", sessionHash, err)
 						}
 						return account, nil
@@ -903,7 +972,7 @@ func (s *GatewayService) selectAccountWithMixedScheduling(ctx context.Context, g
 
 	// 4. 建立粘性绑定
 	if sessionHash != "" && s.cache != nil {
-		if err := s.cache.SetSessionAccountID(ctx, sessionHash, selected.ID, stickySessionTTL); err != nil {
+		if err := s.cache.SetSessionAccountID(ctx, derefGroupID(groupID), sessionHash, selected.ID, stickySessionTTL); err != nil {
 			log.Printf("set session account failed: session=%s account_id=%d err=%v", sessionHash, selected.ID, err)
 		}
 	}

backend/internal/service/gemini_messages_compat_service.go

@@ -109,7 +109,7 @@ func (s *GeminiMessagesCompatService) SelectAccountForModelWithExclusions(ctx co
 	cacheKey := "gemini:" + sessionHash
 
 	if sessionHash != "" {
-		accountID, err := s.cache.GetSessionAccountID(ctx, cacheKey)
+		accountID, err := s.cache.GetSessionAccountID(ctx, derefGroupID(groupID), cacheKey)
 		if err == nil && accountID > 0 {
 			if _, excluded := excludedIDs[accountID]; !excluded {
 				account, err := s.accountRepo.GetByID(ctx, accountID)
@@ -133,7 +133,7 @@ func (s *GeminiMessagesCompatService) SelectAccountForModelWithExclusions(ctx co
 							}
 						}
 						if usable {
-							_ = s.cache.RefreshSessionTTL(ctx, cacheKey, geminiStickySessionTTL)
+							_ = s.cache.RefreshSessionTTL(ctx, derefGroupID(groupID), cacheKey, geminiStickySessionTTL)
 							return account, nil
 						}
 					}
@@ -217,7 +217,7 @@ func (s *GeminiMessagesCompatService) SelectAccountForModelWithExclusions(ctx co
 	}
 
 	if sessionHash != "" {
-		_ = s.cache.SetSessionAccountID(ctx, cacheKey, selected.ID, geminiStickySessionTTL)
+		_ = s.cache.SetSessionAccountID(ctx, derefGroupID(groupID), cacheKey, selected.ID, geminiStickySessionTTL)
 	}
 
 	return selected, nil

backend/internal/service/gemini_multiplatform_test.go

@@ -190,14 +190,14 @@ type mockGatewayCacheForGemini struct {
 	sessionBindings map[string]int64
 }
 
-func (m *mockGatewayCacheForGemini) GetSessionAccountID(ctx context.Context, sessionHash string) (int64, error) {
+func (m *mockGatewayCacheForGemini) GetSessionAccountID(ctx context.Context, groupID int64, sessionHash string) (int64, error) {
 	if id, ok := m.sessionBindings[sessionHash]; ok {
 		return id, nil
 	}
 	return 0, errors.New("not found")
 }
 
-func (m *mockGatewayCacheForGemini) SetSessionAccountID(ctx context.Context, sessionHash string, accountID int64, ttl time.Duration) error {
+func (m *mockGatewayCacheForGemini) SetSessionAccountID(ctx context.Context, groupID int64, sessionHash string, accountID int64, ttl time.Duration) error {
 	if m.sessionBindings == nil {
 		m.sessionBindings = make(map[string]int64)
 	}
@@ -205,7 +205,7 @@ func (m *mockGatewayCacheForGemini) SetSessionAccountID(ctx context.Context, ses
 	return nil
 }
 
-func (m *mockGatewayCacheForGemini) RefreshSessionTTL(ctx context.Context, sessionHash string, ttl time.Duration) error {
+func (m *mockGatewayCacheForGemini) RefreshSessionTTL(ctx context.Context, groupID int64, sessionHash string, ttl time.Duration) error {
 	return nil
 }
 

backend/internal/service/gemini_oauth_service.go

@@ -120,15 +120,16 @@ func (s *GeminiOAuthService) GenerateAuthURL(ctx context.Context, proxyID *int64
 	}
 
 	// OAuth client selection:
-	// - code_assist: always use built-in Gemini CLI OAuth client (public), regardless of configured client_id/secret.
-	// - google_one: uses configured OAuth client when provided; otherwise falls back to built-in client.
-	// - ai_studio: requires a user-provided OAuth client.
+	// - code_assist: always use built-in Gemini CLI OAuth client (public)
+	// - google_one: always use built-in Gemini CLI OAuth client (public)
+	// - ai_studio: requires a user-provided OAuth client
 	oauthCfg := geminicli.OAuthConfig{
 		ClientID:     s.cfg.Gemini.OAuth.ClientID,
 		ClientSecret: s.cfg.Gemini.OAuth.ClientSecret,
 		Scopes:       s.cfg.Gemini.OAuth.Scopes,
 	}
-	if oauthType == "code_assist" {
+	if oauthType == "code_assist" || oauthType == "google_one" {
+		// Force use of built-in Gemini CLI OAuth client
 		oauthCfg.ClientID = ""
 		oauthCfg.ClientSecret = ""
 	}
@@ -576,6 +577,20 @@ func (s *GeminiOAuthService) ExchangeCode(ctx context.Context, input *GeminiExch
 
 	case "google_one":
 		log.Printf("[GeminiOAuth] Processing google_one OAuth type")
+
+		// Google One accounts use cloudaicompanion API, which requires a project_id.
+		// For personal accounts, Google auto-assigns a project_id via the LoadCodeAssist API.
+		if projectID == "" {
+			log.Printf("[GeminiOAuth] No project_id provided, attempting to fetch from LoadCodeAssist API...")
+			var err error
+			projectID, _, err = s.fetchProjectID(ctx, tokenResp.AccessToken, proxyURL)
+			if err != nil {
+				log.Printf("[GeminiOAuth] ERROR: Failed to fetch project_id: %v", err)
+				return nil, fmt.Errorf("google One accounts require a project_id, failed to auto-detect: %w", err)
+			}
+			log.Printf("[GeminiOAuth] Successfully fetched project_id: %s", projectID)
+		}
+
 		log.Printf("[GeminiOAuth] Attempting to fetch Google One tier from Drive API...")
 		// Attempt to fetch Drive storage tier
 		var storageInfo *geminicli.DriveStorageInfo

backend/internal/service/gemini_oauth_service_test.go

@@ -40,7 +40,7 @@ func TestGeminiOAuthService_GenerateAuthURL_RedirectURIStrategy(t *testing.T) {
 			wantProjectID: "",
 		},
 		{
-			name: "google_one uses custom client when configured and redirects to localhost",
+			name: "google_one always forces built-in client even when custom client configured",
 			cfg: &config.Config{
 				Gemini: config.GeminiConfig{
 					OAuth: config.GeminiOAuthConfig{
@@ -50,9 +50,9 @@ func TestGeminiOAuthService_GenerateAuthURL_RedirectURIStrategy(t *testing.T) {
 				},
 			},
 			oauthType:     "google_one",
-			wantClientID:  "custom-client-id",
-			wantRedirect:  geminicli.AIStudioOAuthRedirectURI,
-			wantScope:     geminicli.DefaultGoogleOneScopes,
+			wantClientID:  geminicli.GeminiCLIOAuthClientID,
+			wantRedirect:  geminicli.GeminiCLIRedirectURI,
+			wantScope:     geminicli.DefaultCodeAssistScopes,
 			wantProjectID: "",
 		},
 		{

backend/internal/service/group.go

@@ -22,6 +22,10 @@ type Group struct {
 	ImagePrice2K *float64
 	ImagePrice4K *float64
 
+	// Claude Code 客户端限制
+	ClaudeCodeOnly  bool
+	FallbackGroupID *int64
+
 	CreatedAt time.Time
 	UpdatedAt time.Time
 

backend/internal/service/openai_gateway_service.go

@@ -134,11 +134,11 @@ func (s *OpenAIGatewayService) GenerateSessionHash(c *gin.Context) string {
 }
 
 // BindStickySession sets session -> account binding with standard TTL.
-func (s *OpenAIGatewayService) BindStickySession(ctx context.Context, sessionHash string, accountID int64) error {
+func (s *OpenAIGatewayService) BindStickySession(ctx context.Context, groupID *int64, sessionHash string, accountID int64) error {
 	if sessionHash == "" || accountID <= 0 {
 		return nil
 	}
-	return s.cache.SetSessionAccountID(ctx, "openai:"+sessionHash, accountID, openaiStickySessionTTL)
+	return s.cache.SetSessionAccountID(ctx, derefGroupID(groupID), "openai:"+sessionHash, accountID, openaiStickySessionTTL)
 }
 
 // SelectAccount selects an OpenAI account with sticky session support
@@ -155,13 +155,13 @@ func (s *OpenAIGatewayService) SelectAccountForModel(ctx context.Context, groupI
 func (s *OpenAIGatewayService) SelectAccountForModelWithExclusions(ctx context.Context, groupID *int64, sessionHash string, requestedModel string, excludedIDs map[int64]struct{}) (*Account, error) {
 	// 1. Check sticky session
 	if sessionHash != "" {
-		accountID, err := s.cache.GetSessionAccountID(ctx, "openai:"+sessionHash)
+		accountID, err := s.cache.GetSessionAccountID(ctx, derefGroupID(groupID), "openai:"+sessionHash)
 		if err == nil && accountID > 0 {
 			if _, excluded := excludedIDs[accountID]; !excluded {
 				account, err := s.accountRepo.GetByID(ctx, accountID)
 				if err == nil && account.IsSchedulable() && account.IsOpenAI() && (requestedModel == "" || account.IsModelSupported(requestedModel)) {
 					// Refresh sticky session TTL
-					_ = s.cache.RefreshSessionTTL(ctx, "openai:"+sessionHash, openaiStickySessionTTL)
+					_ = s.cache.RefreshSessionTTL(ctx, derefGroupID(groupID), "openai:"+sessionHash, openaiStickySessionTTL)
 					return account, nil
 				}
 			}
@@ -227,7 +227,7 @@ func (s *OpenAIGatewayService) SelectAccountForModelWithExclusions(ctx context.C
 
 	// 4. Set sticky session
 	if sessionHash != "" {
-		_ = s.cache.SetSessionAccountID(ctx, "openai:"+sessionHash, selected.ID, openaiStickySessionTTL)
+		_ = s.cache.SetSessionAccountID(ctx, derefGroupID(groupID), "openai:"+sessionHash, selected.ID, openaiStickySessionTTL)
 	}
 
 	return selected, nil
@@ -238,7 +238,7 @@ func (s *OpenAIGatewayService) SelectAccountWithLoadAwareness(ctx context.Contex
 	cfg := s.schedulingConfig()
 	var stickyAccountID int64
 	if sessionHash != "" && s.cache != nil {
-		if accountID, err := s.cache.GetSessionAccountID(ctx, "openai:"+sessionHash); err == nil {
+		if accountID, err := s.cache.GetSessionAccountID(ctx, derefGroupID(groupID), "openai:"+sessionHash); err == nil {
 			stickyAccountID = accountID
 		}
 	}
@@ -298,14 +298,14 @@ func (s *OpenAIGatewayService) SelectAccountWithLoadAwareness(ctx context.Contex
 
 	// ============ Layer 1: Sticky session ============
 	if sessionHash != "" {
-		accountID, err := s.cache.GetSessionAccountID(ctx, "openai:"+sessionHash)
+		accountID, err := s.cache.GetSessionAccountID(ctx, derefGroupID(groupID), "openai:"+sessionHash)
 		if err == nil && accountID > 0 && !isExcluded(accountID) {
 			account, err := s.accountRepo.GetByID(ctx, accountID)
 			if err == nil && account.IsSchedulable() && account.IsOpenAI() &&
 				(requestedModel == "" || account.IsModelSupported(requestedModel)) {
 				result, err := s.tryAcquireAccountSlot(ctx, accountID, account.Concurrency)
 				if err == nil && result.Acquired {
-					_ = s.cache.RefreshSessionTTL(ctx, "openai:"+sessionHash, openaiStickySessionTTL)
+					_ = s.cache.RefreshSessionTTL(ctx, derefGroupID(groupID), "openai:"+sessionHash, openaiStickySessionTTL)
 					return &AccountSelectionResult{
 						Account:     account,
 						Acquired:    true,
@@ -362,7 +362,7 @@ func (s *OpenAIGatewayService) SelectAccountWithLoadAwareness(ctx context.Contex
 			result, err := s.tryAcquireAccountSlot(ctx, acc.ID, acc.Concurrency)
 			if err == nil && result.Acquired {
 				if sessionHash != "" {
-					_ = s.cache.SetSessionAccountID(ctx, "openai:"+sessionHash, acc.ID, openaiStickySessionTTL)
+					_ = s.cache.SetSessionAccountID(ctx, derefGroupID(groupID), "openai:"+sessionHash, acc.ID, openaiStickySessionTTL)
 				}
 				return &AccountSelectionResult{
 					Account:     acc,
@@ -415,7 +415,7 @@ func (s *OpenAIGatewayService) SelectAccountWithLoadAwareness(ctx context.Contex
 				result, err := s.tryAcquireAccountSlot(ctx, item.account.ID, item.account.Concurrency)
 				if err == nil && result.Acquired {
 					if sessionHash != "" {
-						_ = s.cache.SetSessionAccountID(ctx, "openai:"+sessionHash, item.account.ID, openaiStickySessionTTL)
+						_ = s.cache.SetSessionAccountID(ctx, derefGroupID(groupID), "openai:"+sessionHash, item.account.ID, openaiStickySessionTTL)
 					}
 					return &AccountSelectionResult{
 						Account:     item.account,
@@ -540,10 +540,19 @@ func (s *OpenAIGatewayService) Forward(ctx context.Context, c *gin.Context, acco
 		bodyModified = true
 	}
 
-	// For OAuth accounts using ChatGPT internal API, add store: false
+	// For OAuth accounts using ChatGPT internal API:
+	// 1. Add store: false
+	// 2. Normalize input format for Codex API compatibility
 	if account.Type == AccountTypeOAuth {
 		reqBody["store"] = false
 		bodyModified = true
+
+		// Normalize input format: convert AI SDK multi-part content format to simplified format
+		// AI SDK sends: {"content": [{"type": "input_text", "text": "..."}]}
+		// Codex API expects: {"content": "..."}
+		if normalizeInputForCodexAPI(reqBody) {
+			bodyModified = true
+		}
 	}
 
 	// Re-serialize body only if modified
@@ -1085,6 +1094,101 @@ func (s *OpenAIGatewayService) replaceModelInResponseBody(body []byte, fromModel
 	return newBody
 }
 
+// normalizeInputForCodexAPI converts AI SDK multi-part content format to simplified format
+// that the ChatGPT internal Codex API expects.
+//
+// AI SDK sends content as an array of typed objects:
+//
+//	{"content": [{"type": "input_text", "text": "hello"}]}
+//
+// ChatGPT Codex API expects content as a simple string:
+//
+//	{"content": "hello"}
+//
+// This function modifies reqBody in-place and returns true if any modification was made.
+func normalizeInputForCodexAPI(reqBody map[string]any) bool {
+	input, ok := reqBody["input"]
+	if !ok {
+		return false
+	}
+
+	// Handle case where input is a simple string (already compatible)
+	if _, isString := input.(string); isString {
+		return false
+	}
+
+	// Handle case where input is an array of messages
+	inputArray, ok := input.([]any)
+	if !ok {
+		return false
+	}
+
+	modified := false
+	for _, item := range inputArray {
+		message, ok := item.(map[string]any)
+		if !ok {
+			continue
+		}
+
+		content, ok := message["content"]
+		if !ok {
+			continue
+		}
+
+		// If content is already a string, no conversion needed
+		if _, isString := content.(string); isString {
+			continue
+		}
+
+		// If content is an array (AI SDK format), convert to string
+		contentArray, ok := content.([]any)
+		if !ok {
+			continue
+		}
+
+		// Extract text from content array
+		var textParts []string
+		for _, part := range contentArray {
+			partMap, ok := part.(map[string]any)
+			if !ok {
+				continue
+			}
+
+			// Handle different content types
+			partType, _ := partMap["type"].(string)
+			switch partType {
+			case "input_text", "text":
+				// Extract text from input_text or text type
+				if text, ok := partMap["text"].(string); ok {
+					textParts = append(textParts, text)
+				}
+			case "input_image", "image":
+				// For images, we need to preserve the original format
+				// as ChatGPT Codex API may support images in a different way
+				// For now, skip image parts (they will be lost in conversion)
+				// TODO: Consider preserving image data or handling it separately
+				continue
+			case "input_file", "file":
+				// Similar to images, file inputs may need special handling
+				continue
+			default:
+				// For unknown types, try to extract text if available
+				if text, ok := partMap["text"].(string); ok {
+					textParts = append(textParts, text)
+				}
+			}
+		}
+
+		// Convert content array to string
+		if len(textParts) > 0 {
+			message["content"] = strings.Join(textParts, "\n")
+			modified = true
+		}
+	}
+
+	return modified
+}
+
 // OpenAIRecordUsageInput input for recording usage
 type OpenAIRecordUsageInput struct {
 	Result       *OpenAIForwardResult

backend/internal/service/proxy_service.go

@@ -20,6 +20,7 @@ type ProxyRepository interface {
 
 	List(ctx context.Context, params pagination.PaginationParams) ([]Proxy, *pagination.PaginationResult, error)
 	ListWithFilters(ctx context.Context, params pagination.PaginationParams, protocol, status, search string) ([]Proxy, *pagination.PaginationResult, error)
+	ListWithFiltersAndAccountCount(ctx context.Context, params pagination.PaginationParams, protocol, status, search string) ([]ProxyWithAccountCount, *pagination.PaginationResult, error)
 	ListActive(ctx context.Context) ([]Proxy, error)
 	ListActiveWithAccountCount(ctx context.Context) ([]ProxyWithAccountCount, error)
 

backend/migrations/029_add_group_claude_code_restriction.sql

@@ -0,0 +1,21 @@
+-- 029_add_group_claude_code_restriction.sql
+-- 添加分组级别的 Claude Code 客户端限制功能
+
+-- 添加 claude_code_only 字段：是否仅允许 Claude Code 客户端
+ALTER TABLE groups
+ADD COLUMN IF NOT EXISTS claude_code_only BOOLEAN NOT NULL DEFAULT FALSE;
+
+-- 添加 fallback_group_id 字段：非 Claude Code 请求降级到的分组
+ALTER TABLE groups
+ADD COLUMN IF NOT EXISTS fallback_group_id BIGINT REFERENCES groups(id) ON DELETE SET NULL;
+
+-- 添加索引优化查询
+CREATE INDEX IF NOT EXISTS idx_groups_claude_code_only
+ON groups(claude_code_only) WHERE deleted_at IS NULL;
+
+CREATE INDEX IF NOT EXISTS idx_groups_fallback_group_id
+ON groups(fallback_group_id) WHERE deleted_at IS NULL AND fallback_group_id IS NOT NULL;
+
+-- 添加字段注释
+COMMENT ON COLUMN groups.claude_code_only IS '是否仅允许 Claude Code 客户端访问此分组';
+COMMENT ON COLUMN groups.fallback_group_id IS '非 Claude Code 请求降级使用的分组 ID';

frontend/src/components/account/CreateAccountModal.vue

@@ -166,7 +166,7 @@
           >
             <div
               :class="[
-                'flex h-8 w-8 items-center justify-center rounded-lg',
+                'flex h-8 w-8 shrink-0 items-center justify-center rounded-lg',
                 accountCategory === 'oauth-based'
                   ? 'bg-orange-500 text-white'
                   : 'bg-gray-100 text-gray-500 dark:bg-dark-600 dark:text-gray-400'
@@ -196,7 +196,7 @@
           >
             <div
               :class="[
-                'flex h-8 w-8 items-center justify-center rounded-lg',
+                'flex h-8 w-8 shrink-0 items-center justify-center rounded-lg',
                 accountCategory === 'apikey'
                   ? 'bg-purple-500 text-white'
                   : 'bg-gray-100 text-gray-500 dark:bg-dark-600 dark:text-gray-400'
@@ -232,7 +232,7 @@
           >
             <div
               :class="[
-                'flex h-8 w-8 items-center justify-center rounded-lg',
+                'flex h-8 w-8 shrink-0 items-center justify-center rounded-lg',
                 accountCategory === 'oauth-based'
                   ? 'bg-green-500 text-white'
                   : 'bg-gray-100 text-gray-500 dark:bg-dark-600 dark:text-gray-400'
@@ -258,7 +258,7 @@
           >
             <div
               :class="[
-                'flex h-8 w-8 items-center justify-center rounded-lg',
+                'flex h-8 w-8 shrink-0 items-center justify-center rounded-lg',
                 accountCategory === 'apikey'
                   ? 'bg-purple-500 text-white'
                   : 'bg-gray-100 text-gray-500 dark:bg-dark-600 dark:text-gray-400'
@@ -302,7 +302,7 @@
           >
             <div
               :class="[
-                'flex h-8 w-8 items-center justify-center rounded-lg',
+                'flex h-8 w-8 shrink-0 items-center justify-center rounded-lg',
                 accountCategory === 'oauth-based'
                   ? 'bg-blue-500 text-white'
                   : 'bg-gray-100 text-gray-500 dark:bg-dark-600 dark:text-gray-400'
@@ -332,7 +332,7 @@
           >
             <div
               :class="[
-                'flex h-8 w-8 items-center justify-center rounded-lg',
+                'flex h-8 w-8 shrink-0 items-center justify-center rounded-lg',
                 accountCategory === 'apikey'
                   ? 'bg-purple-500 text-white'
                   : 'bg-gray-100 text-gray-500 dark:bg-dark-600 dark:text-gray-400'
@@ -397,7 +397,7 @@
             >
               <div
                 :class="[
-                  'flex h-8 w-8 items-center justify-center rounded-lg',
+                  'flex h-8 w-8 shrink-0 items-center justify-center rounded-lg',
                   geminiOAuthType === 'google_one'
                     ? 'bg-purple-500 text-white'
                     : 'bg-gray-100 text-gray-500 dark:bg-dark-600 dark:text-gray-400'
@@ -440,7 +440,7 @@
             >
               <div
                 :class="[
-                  'flex h-8 w-8 items-center justify-center rounded-lg',
+                  'flex h-8 w-8 shrink-0 items-center justify-center rounded-lg',
                   geminiOAuthType === 'code_assist'
                     ? 'bg-blue-500 text-white'
                     : 'bg-gray-100 text-gray-500 dark:bg-dark-600 dark:text-gray-400'
@@ -518,7 +518,7 @@
             >
               <div
                 :class="[
-                  'flex h-8 w-8 items-center justify-center rounded-lg',
+                  'flex h-8 w-8 shrink-0 items-center justify-center rounded-lg',
                   geminiOAuthType === 'ai_studio'
                     ? 'bg-amber-500 text-white'
                     : 'bg-gray-100 text-gray-500 dark:bg-dark-600 dark:text-gray-400'
@@ -621,7 +621,7 @@
           <div
             class="flex items-center gap-3 rounded-lg border-2 border-purple-500 bg-purple-50 p-3 dark:bg-purple-900/20"
           >
-            <div class="flex h-8 w-8 items-center justify-center rounded-lg bg-purple-500 text-white">
+            <div class="flex h-8 w-8 shrink-0 items-center justify-center rounded-lg bg-purple-500 text-white">
               <Icon name="key" size="sm" />
             </div>
             <div>

frontend/src/components/account/ReAuthAccountModal.vue

@@ -73,113 +73,48 @@
         </div>
       </fieldset>
 
-      <!-- Gemini OAuth Type Selection -->
-      <fieldset v-if="isGemini" class="border-0 p-0">
-        <legend class="input-label">{{ t('admin.accounts.oauth.gemini.oauthTypeLabel') }}</legend>
-        <div class="mt-2 grid grid-cols-3 gap-3">
-          <button
-            type="button"
-            @click="handleSelectGeminiOAuthType('google_one')"
-            :class="[
-              'flex items-center gap-3 rounded-lg border-2 p-3 text-left transition-all',
-              geminiOAuthType === 'google_one'
-                ? 'border-purple-500 bg-purple-50 dark:bg-purple-900/20'
-                : 'border-gray-200 hover:border-purple-300 dark:border-dark-600 dark:hover:border-purple-700'
-            ]"
-          >
-            <div
-              :class="[
-                'flex h-8 w-8 items-center justify-center rounded-lg',
-                geminiOAuthType === 'google_one'
-                  ? 'bg-purple-500 text-white'
-                  : 'bg-gray-100 text-gray-500 dark:bg-dark-600 dark:text-gray-400'
-              ]"
-            >
-              <svg class="h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor" stroke-width="1.5">
-                <path stroke-linecap="round" stroke-linejoin="round" d="M15.75 6a3.75 3.75 0 11-7.5 0 3.75 3.75 0 017.5 0zM4.501 20.118a7.5 7.5 0 0114.998 0A17.933 17.933 0 0112 21.75c-2.676 0-5.216-.584-7.499-1.632z" />
-              </svg>
-            </div>
-            <div class="min-w-0">
-              <span class="block text-sm font-medium text-gray-900 dark:text-white">Google One</span>
-              <span class="text-xs text-gray-500 dark:text-gray-400">个人账号</span>
-            </div>
-          </button>
-
-          <button
-            type="button"
-            @click="handleSelectGeminiOAuthType('code_assist')"
-            :class="[
-              'flex items-center gap-3 rounded-lg border-2 p-3 text-left transition-all',
-              geminiOAuthType === 'code_assist'
-                ? 'border-blue-500 bg-blue-50 dark:bg-blue-900/20'
-                : 'border-gray-200 hover:border-blue-300 dark:border-dark-600 dark:hover:border-blue-700'
-            ]"
-          >
-            <div
-              :class="[
-                'flex h-8 w-8 items-center justify-center rounded-lg',
-                geminiOAuthType === 'code_assist'
-                  ? 'bg-blue-500 text-white'
-                  : 'bg-gray-100 text-gray-500 dark:bg-dark-600 dark:text-gray-400'
-              ]"
-            >
-              <Icon name="cloud" size="sm" />
-            </div>
-            <div class="min-w-0">
-              <span class="block text-sm font-medium text-gray-900 dark:text-white">
-                {{ t('admin.accounts.gemini.oauthType.builtInTitle') }}
-              </span>
-              <span class="text-xs text-gray-500 dark:text-gray-400">
-                {{ t('admin.accounts.gemini.oauthType.builtInDesc') }}
-              </span>
-            </div>
-          </button>
-
-          <button
-            type="button"
-            :disabled="!geminiAIStudioOAuthEnabled"
-            @click="handleSelectGeminiOAuthType('ai_studio')"
-            :class="[
-              'flex items-center gap-3 rounded-lg border-2 p-3 text-left transition-all',
-              !geminiAIStudioOAuthEnabled ? 'cursor-not-allowed opacity-60' : '',
-              geminiOAuthType === 'ai_studio'
-                ? 'border-purple-500 bg-purple-50 dark:bg-purple-900/20'
-                : 'border-gray-200 hover:border-purple-300 dark:border-dark-600 dark:hover:border-purple-700'
-            ]"
-          >
-            <div
-              :class="[
-                'flex h-8 w-8 items-center justify-center rounded-lg',
-                geminiOAuthType === 'ai_studio'
-                  ? 'bg-purple-500 text-white'
-                  : 'bg-gray-100 text-gray-500 dark:bg-dark-600 dark:text-gray-400'
-              ]"
-            >
-              <Icon name="sparkles" size="sm" />
-            </div>
-            <div class="min-w-0">
-              <span class="block text-sm font-medium text-gray-900 dark:text-white">
-                {{ t('admin.accounts.gemini.oauthType.customTitle') }}
-              </span>
-              <span class="text-xs text-gray-500 dark:text-gray-400">
-                {{ t('admin.accounts.gemini.oauthType.customDesc') }}
-              </span>
-              <div v-if="!geminiAIStudioOAuthEnabled" class="group relative mt-1 inline-block">
-                <span
-                  class="rounded bg-amber-100 px-2 py-0.5 text-xs text-amber-700 dark:bg-amber-900/30 dark:text-amber-300"
-                >
-                  {{ t('admin.accounts.oauth.gemini.aiStudioNotConfiguredShort') }}
-                </span>
-                <div
-                  class="pointer-events-none absolute left-0 top-full z-10 mt-2 w-[28rem] rounded-md border border-amber-200 bg-amber-50 px-3 py-2 text-xs text-amber-800 opacity-0 shadow-sm transition-opacity group-hover:opacity-100 dark:border-amber-700 dark:bg-amber-900/40 dark:text-amber-200"
-                >
-                  {{ t('admin.accounts.oauth.gemini.aiStudioNotConfiguredTip') }}
-                </div>
-              </div>
-            </div>
-          </button>
+      <!-- Gemini OAuth Type Display (read-only) -->
+      <div v-if="isGemini" class="rounded-lg border border-gray-200 bg-gray-50 p-4 dark:border-dark-600 dark:bg-dark-700">
+        <div class="mb-2 text-sm font-medium text-gray-700 dark:text-gray-300">
+          {{ t('admin.accounts.oauth.gemini.oauthTypeLabel') }}
         </div>
-      </fieldset>
+        <div class="flex items-center gap-3">
+          <div
+            :class="[
+              'flex h-8 w-8 shrink-0 items-center justify-center rounded-lg',
+              geminiOAuthType === 'google_one'
+                ? 'bg-purple-500 text-white'
+                : geminiOAuthType === 'code_assist'
+                  ? 'bg-blue-500 text-white'
+                  : 'bg-amber-500 text-white'
+            ]"
+          >
+            <Icon v-if="geminiOAuthType === 'google_one'" name="user" size="sm" />
+            <Icon v-else-if="geminiOAuthType === 'code_assist'" name="cloud" size="sm" />
+            <Icon v-else name="sparkles" size="sm" />
+          </div>
+          <div>
+            <span class="block text-sm font-medium text-gray-900 dark:text-white">
+              {{
+                geminiOAuthType === 'google_one'
+                  ? 'Google One'
+                  : geminiOAuthType === 'code_assist'
+                    ? t('admin.accounts.gemini.oauthType.builtInTitle')
+                    : t('admin.accounts.gemini.oauthType.customTitle')
+              }}
+            </span>
+            <span class="text-xs text-gray-500 dark:text-gray-400">
+              {{
+                geminiOAuthType === 'google_one'
+                  ? '个人账号'
+                  : geminiOAuthType === 'code_assist'
+                    ? t('admin.accounts.gemini.oauthType.builtInDesc')
+                    : t('admin.accounts.gemini.oauthType.customDesc')
+              }}
+            </span>
+          </div>
+        </div>
+      </div>
 
       <OAuthAuthorizationFlow
         ref="oauthFlowRef"
@@ -299,7 +234,6 @@ const oauthFlowRef = ref<OAuthFlowExposed | null>(null)
 // State
 const addMethod = ref<AddMethod>('oauth')
 const geminiOAuthType = ref<'code_assist' | 'google_one' | 'ai_studio'>('code_assist')
-const geminiAIStudioOAuthEnabled = ref(false)
 
 // Computed - check platform
 const isOpenAI = computed(() => props.account?.platform === 'openai')
@@ -367,14 +301,6 @@ watch(
               ? 'ai_studio'
               : 'code_assist'
       }
-      if (isGemini.value) {
-        geminiOAuth.getCapabilities().then((caps) => {
-          geminiAIStudioOAuthEnabled.value = !!caps?.ai_studio_oauth_enabled
-          if (!geminiAIStudioOAuthEnabled.value && geminiOAuthType.value === 'ai_studio') {
-            geminiOAuthType.value = 'code_assist'
-          }
-        })
-      }
     } else {
       resetState()
     }
@@ -385,7 +311,6 @@ watch(
 const resetState = () => {
   addMethod.value = 'oauth'
   geminiOAuthType.value = 'code_assist'
-  geminiAIStudioOAuthEnabled.value = false
   claudeOAuth.resetState()
   openaiOAuth.resetState()
   geminiOAuth.resetState()
@@ -393,14 +318,6 @@ const resetState = () => {
   oauthFlowRef.value?.reset()
 }
 
-const handleSelectGeminiOAuthType = (oauthType: 'code_assist' | 'google_one' | 'ai_studio') => {
-  if (oauthType === 'ai_studio' && !geminiAIStudioOAuthEnabled.value) {
-    appStore.showError(t('admin.accounts.oauth.gemini.aiStudioNotConfigured'))
-    return
-  }
-  geminiOAuthType.value = oauthType
-}
-
 const handleClose = () => {
   emit('close')
 }

frontend/src/components/admin/account/ReAuthAccountModal.vue

@@ -73,111 +73,48 @@
         </div>
       </fieldset>
 
-      <!-- Gemini OAuth Type Selection -->
-      <fieldset v-if="isGemini" class="border-0 p-0">
-        <legend class="input-label">{{ t('admin.accounts.oauth.gemini.oauthTypeLabel') }}</legend>
-        <div class="mt-2 grid grid-cols-3 gap-3">
-          <button
-            type="button"
-            @click="handleSelectGeminiOAuthType('google_one')"
-            :class="[
-              'flex items-center gap-3 rounded-lg border-2 p-3 text-left transition-all',
-              geminiOAuthType === 'google_one'
-                ? 'border-purple-500 bg-purple-50 dark:bg-purple-900/20'
-                : 'border-gray-200 hover:border-purple-300 dark:border-dark-600 dark:hover:border-purple-700'
-            ]"
-          >
-            <div
-              :class="[
-                'flex h-8 w-8 items-center justify-center rounded-lg',
-                geminiOAuthType === 'google_one'
-                  ? 'bg-purple-500 text-white'
-                  : 'bg-gray-100 text-gray-500 dark:bg-dark-600 dark:text-gray-400'
-              ]"
-            >
-              <Icon name="user" size="sm" />
-            </div>
-            <div class="min-w-0">
-              <span class="block text-sm font-medium text-gray-900 dark:text-white">Google One</span>
-              <span class="text-xs text-gray-500 dark:text-gray-400">个人账号</span>
-            </div>
-          </button>
-
-          <button
-            type="button"
-            @click="handleSelectGeminiOAuthType('code_assist')"
-            :class="[
-              'flex items-center gap-3 rounded-lg border-2 p-3 text-left transition-all',
-              geminiOAuthType === 'code_assist'
-                ? 'border-blue-500 bg-blue-50 dark:bg-blue-900/20'
-                : 'border-gray-200 hover:border-blue-300 dark:border-dark-600 dark:hover:border-blue-700'
-            ]"
-          >
-            <div
-              :class="[
-                'flex h-8 w-8 items-center justify-center rounded-lg',
-                geminiOAuthType === 'code_assist'
-                  ? 'bg-blue-500 text-white'
-                  : 'bg-gray-100 text-gray-500 dark:bg-dark-600 dark:text-gray-400'
-              ]"
-            >
-              <Icon name="cloud" size="sm" />
-            </div>
-            <div class="min-w-0">
-              <span class="block text-sm font-medium text-gray-900 dark:text-white">
-                {{ t('admin.accounts.gemini.oauthType.builtInTitle') }}
-              </span>
-              <span class="text-xs text-gray-500 dark:text-gray-400">
-                {{ t('admin.accounts.gemini.oauthType.builtInDesc') }}
-              </span>
-            </div>
-          </button>
-
-          <button
-            type="button"
-            :disabled="!geminiAIStudioOAuthEnabled"
-            @click="handleSelectGeminiOAuthType('ai_studio')"
-            :class="[
-              'flex items-center gap-3 rounded-lg border-2 p-3 text-left transition-all',
-              !geminiAIStudioOAuthEnabled ? 'cursor-not-allowed opacity-60' : '',
-              geminiOAuthType === 'ai_studio'
-                ? 'border-purple-500 bg-purple-50 dark:bg-purple-900/20'
-                : 'border-gray-200 hover:border-purple-300 dark:border-dark-600 dark:hover:border-purple-700'
-            ]"
-          >
-            <div
-              :class="[
-                'flex h-8 w-8 items-center justify-center rounded-lg',
-                geminiOAuthType === 'ai_studio'
-                  ? 'bg-purple-500 text-white'
-                  : 'bg-gray-100 text-gray-500 dark:bg-dark-600 dark:text-gray-400'
-              ]"
-            >
-              <Icon name="sparkles" size="sm" />
-            </div>
-            <div class="min-w-0">
-              <span class="block text-sm font-medium text-gray-900 dark:text-white">
-                {{ t('admin.accounts.gemini.oauthType.customTitle') }}
-              </span>
-              <span class="text-xs text-gray-500 dark:text-gray-400">
-                {{ t('admin.accounts.gemini.oauthType.customDesc') }}
-              </span>
-              <div v-if="!geminiAIStudioOAuthEnabled" class="group relative mt-1 inline-block">
-                <span
-                  class="rounded bg-amber-100 px-2 py-0.5 text-xs text-amber-700 dark:bg-amber-900/30 dark:text-amber-300"
-                >
-                  {{ t('admin.accounts.oauth.gemini.aiStudioNotConfiguredShort') }}
-                </span>
-                <div
-                  class="pointer-events-none absolute left-0 top-full z-10 mt-2 w-[28rem] rounded-md border border-amber-200 bg-amber-50 px-3 py-2 text-xs text-amber-800 opacity-0 shadow-sm transition-opacity group-hover:opacity-100 dark:border-amber-700 dark:bg-amber-900/40 dark:text-amber-200"
-                >
-                  {{ t('admin.accounts.oauth.gemini.aiStudioNotConfiguredTip') }}
-                </div>
-              </div>
-            </div>
-          </button>
+      <!-- Gemini OAuth Type Display (read-only) -->
+      <div v-if="isGemini" class="rounded-lg border border-gray-200 bg-gray-50 p-4 dark:border-dark-600 dark:bg-dark-700">
+        <div class="mb-2 text-sm font-medium text-gray-700 dark:text-gray-300">
+          {{ t('admin.accounts.oauth.gemini.oauthTypeLabel') }}
         </div>
-      </fieldset>
+        <div class="flex items-center gap-3">
+          <div
+            :class="[
+              'flex h-8 w-8 shrink-0 items-center justify-center rounded-lg',
+              geminiOAuthType === 'google_one'
+                ? 'bg-purple-500 text-white'
+                : geminiOAuthType === 'code_assist'
+                  ? 'bg-blue-500 text-white'
+                  : 'bg-amber-500 text-white'
+            ]"
+          >
+            <Icon v-if="geminiOAuthType === 'google_one'" name="user" size="sm" />
+            <Icon v-else-if="geminiOAuthType === 'code_assist'" name="cloud" size="sm" />
+            <Icon v-else name="sparkles" size="sm" />
+          </div>
+          <div>
+            <span class="block text-sm font-medium text-gray-900 dark:text-white">
+              {{
+                geminiOAuthType === 'google_one'
+                  ? 'Google One'
+                  : geminiOAuthType === 'code_assist'
+                    ? t('admin.accounts.gemini.oauthType.builtInTitle')
+                    : t('admin.accounts.gemini.oauthType.customTitle')
+              }}
+            </span>
+            <span class="text-xs text-gray-500 dark:text-gray-400">
+              {{
+                geminiOAuthType === 'google_one'
+                  ? '个人账号'
+                  : geminiOAuthType === 'code_assist'
+                    ? t('admin.accounts.gemini.oauthType.builtInDesc')
+                    : t('admin.accounts.gemini.oauthType.customDesc')
+              }}
+            </span>
+          </div>
+        </div>
+      </div>
 
       <OAuthAuthorizationFlow
         ref="oauthFlowRef"
@@ -297,7 +234,6 @@ const oauthFlowRef = ref<OAuthFlowExposed | null>(null)
 // State
 const addMethod = ref<AddMethod>('oauth')
 const geminiOAuthType = ref<'code_assist' | 'google_one' | 'ai_studio'>('code_assist')
-const geminiAIStudioOAuthEnabled = ref(false)
 
 // Computed - check platform
 const isOpenAI = computed(() => props.account?.platform === 'openai')
@@ -365,14 +301,6 @@ watch(
               ? 'ai_studio'
               : 'code_assist'
       }
-      if (isGemini.value) {
-        geminiOAuth.getCapabilities().then((caps) => {
-          geminiAIStudioOAuthEnabled.value = !!caps?.ai_studio_oauth_enabled
-          if (!geminiAIStudioOAuthEnabled.value && geminiOAuthType.value === 'ai_studio') {
-            geminiOAuthType.value = 'code_assist'
-          }
-        })
-      }
     } else {
       resetState()
     }
@@ -383,7 +311,6 @@ watch(
 const resetState = () => {
   addMethod.value = 'oauth'
   geminiOAuthType.value = 'code_assist'
-  geminiAIStudioOAuthEnabled.value = false
   claudeOAuth.resetState()
   openaiOAuth.resetState()
   geminiOAuth.resetState()
@@ -391,14 +318,6 @@ const resetState = () => {
   oauthFlowRef.value?.reset()
 }
 
-const handleSelectGeminiOAuthType = (oauthType: 'code_assist' | 'google_one' | 'ai_studio') => {
-  if (oauthType === 'ai_studio' && !geminiAIStudioOAuthEnabled.value) {
-    appStore.showError(t('admin.accounts.oauth.gemini.aiStudioNotConfigured'))
-    return
-  }
-  geminiOAuthType.value = oauthType
-}
-
 const handleClose = () => {
   emit('close')
 }

frontend/src/components/admin/usage/UsageTable.vue

@@ -115,15 +115,9 @@
           <span class="text-sm text-gray-600 dark:text-gray-400">{{ formatDateTime(value) }}</span>
         </template>
 
-        <template #cell-request_id="{ row }">
-          <div v-if="row.request_id" class="flex items-center gap-1.5 max-w-[120px]">
-            <span class="font-mono text-xs text-gray-500 dark:text-gray-400 truncate" :title="row.request_id">{{ row.request_id }}</span>
-            <button @click="copyRequestId(row.request_id)" class="flex-shrink-0 rounded p-0.5 transition-colors hover:bg-gray-100 dark:hover:bg-dark-700" :class="copiedRequestId === row.request_id ? 'text-green-500' : 'text-gray-400 hover:text-gray-600 dark:hover:text-gray-300'" :title="copiedRequestId === row.request_id ? t('keys.copied') : t('keys.copyToClipboard')">
-              <svg v-if="copiedRequestId === row.request_id" class="h-3.5 w-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24" stroke-width="2"><path stroke-linecap="round" stroke-linejoin="round" d="M5 13l4 4L19 7" /></svg>
-              <Icon v-else name="copy" size="sm" class="h-3.5 w-3.5" />
-            </button>
-          </div>
-          <span v-else class="text-gray-400 dark:text-gray-500">-</span>
+        <template #cell-user_agent="{ row }">
+          <span v-if="row.user_agent" class="text-sm text-gray-600 dark:text-gray-400 max-w-[150px] truncate block" :title="row.user_agent">{{ formatUserAgent(row.user_agent) }}</span>
+          <span v-else class="text-sm text-gray-400 dark:text-gray-500">-</span>
         </template>
 
         <template #empty><EmptyState :message="t('usage.noRecords')" /></template>
@@ -228,7 +222,6 @@
 import { ref, computed } from 'vue'
 import { useI18n } from 'vue-i18n'
 import { formatDateTime } from '@/utils/format'
-import { useAppStore } from '@/stores/app'
 import DataTable from '@/components/common/DataTable.vue'
 import EmptyState from '@/components/common/EmptyState.vue'
 import Icon from '@/components/icons/Icon.vue'
@@ -236,8 +229,6 @@ import type { UsageLog } from '@/types'
 
 defineProps(['data', 'loading'])
 const { t } = useI18n()
-const appStore = useAppStore()
-const copiedRequestId = ref<string | null>(null)
 
 // Tooltip state - cost
 const tooltipVisible = ref(false)
@@ -262,7 +253,7 @@ const cols = computed(() => [
   { key: 'first_token', label: t('usage.firstToken'), sortable: false },
   { key: 'duration', label: t('usage.duration'), sortable: false },
   { key: 'created_at', label: t('usage.time'), sortable: true },
-  { key: 'request_id', label: t('admin.usage.requestId'), sortable: false }
+  { key: 'user_agent', label: t('usage.userAgent'), sortable: false }
 ])
 
 const formatCacheTokens = (tokens: number): string => {
@@ -271,23 +262,25 @@ const formatCacheTokens = (tokens: number): string => {
   return tokens.toString()
 }
 
+const formatUserAgent = (ua: string): string => {
+  // 提取主要客户端标识
+  if (ua.includes('claude-cli')) return ua.match(/claude-cli\/[\d.]+/)?.[0] || 'Claude CLI'
+  if (ua.includes('Cursor')) return 'Cursor'
+  if (ua.includes('VSCode') || ua.includes('vscode')) return 'VS Code'
+  if (ua.includes('Continue')) return 'Continue'
+  if (ua.includes('Cline')) return 'Cline'
+  if (ua.includes('OpenAI')) return 'OpenAI SDK'
+  if (ua.includes('anthropic')) return 'Anthropic SDK'
+  // 截断过长的 UA
+  return ua.length > 30 ? ua.substring(0, 30) + '...' : ua
+}
+
 const formatDuration = (ms: number | null | undefined): string => {
   if (ms == null) return '-'
   if (ms < 1000) return `${ms}ms`
   return `${(ms / 1000).toFixed(2)}s`
 }
 
-const copyRequestId = async (requestId: string) => {
-  try {
-    await navigator.clipboard.writeText(requestId)
-    copiedRequestId.value = requestId
-    appStore.showSuccess(t('admin.usage.requestIdCopied'))
-    setTimeout(() => { copiedRequestId.value = null }, 2000)
-  } catch {
-    appStore.showError(t('common.copyFailed'))
-  }
-}
-
 // Cost tooltip functions
 const showTooltip = (event: MouseEvent, row: UsageLog) => {
   const target = event.currentTarget as HTMLElement

frontend/src/i18n/locales/en.ts

@@ -424,7 +424,8 @@ export default {
     billingType: 'Billing',
     balance: 'Balance',
     subscription: 'Subscription',
-    imageUnit: ' images'
+    imageUnit: ' images',
+    userAgent: 'User-Agent'
   },
 
   // Redeem
@@ -856,6 +857,15 @@ export default {
       imagePricing: {
         title: 'Image Generation Pricing',
         description: 'Configure pricing for gemini-3-pro-image model. Leave empty to use default prices.'
+      },
+      claudeCode: {
+        title: 'Claude Code Client Restriction',
+        tooltip: 'When enabled, this group only allows official Claude Code clients. Non-Claude Code requests will be rejected or fallback to the specified group.',
+        enabled: 'Claude Code Only',
+        disabled: 'Allow All Clients',
+        fallbackGroup: 'Fallback Group',
+        fallbackHint: 'Non-Claude Code requests will use this group. Leave empty to reject directly.',
+        noFallback: 'No Fallback (Reject)'
       }
     },
 
@@ -1560,6 +1570,7 @@ export default {
         protocol: 'Protocol',
         address: 'Address',
         status: 'Status',
+        accounts: 'Accounts',
         actions: 'Actions'
       },
       testConnection: 'Test Connection',

frontend/src/i18n/locales/zh.ts

@@ -421,7 +421,8 @@ export default {
     billingType: '消费类型',
     balance: '余额',
     subscription: '订阅',
-    imageUnit: '张'
+    imageUnit: '张',
+    userAgent: 'User-Agent'
   },
 
   // Redeem
@@ -933,6 +934,15 @@ export default {
       imagePricing: {
         title: '图片生成计费',
         description: '配置 gemini-3-pro-image 模型的图片生成价格，留空则使用默认价格'
+      },
+      claudeCode: {
+        title: 'Claude Code 客户端限制',
+        tooltip: '启用后，此分组仅允许 Claude Code 官方客户端访问。非 Claude Code 请求将被拒绝或降级到指定分组。',
+        enabled: '仅限 Claude Code',
+        disabled: '允许所有客户端',
+        fallbackGroup: '降级分组',
+        fallbackHint: '非 Claude Code 请求将使用此分组，留空则直接拒绝',
+        noFallback: '不降级（直接拒绝）'
       }
     },
 
@@ -1646,6 +1656,7 @@ export default {
         protocol: '协议',
         address: '地址',
         status: '状态',
+        accounts: '账号数',
         actions: '操作',
         nameLabel: '名称',
         namePlaceholder: '请输入代理名称',

frontend/src/types/index.ts

@@ -263,6 +263,9 @@ export interface Group {
   image_price_1k: number | null
   image_price_2k: number | null
   image_price_4k: number | null
+  // Claude Code 客户端限制
+  claude_code_only: boolean
+  fallback_group_id: number | null
   account_count?: number
   created_at: string
   updated_at: string
@@ -298,6 +301,15 @@ export interface CreateGroupRequest {
   platform?: GroupPlatform
   rate_multiplier?: number
   is_exclusive?: boolean
+  subscription_type?: SubscriptionType
+  daily_limit_usd?: number | null
+  weekly_limit_usd?: number | null
+  monthly_limit_usd?: number | null
+  image_price_1k?: number | null
+  image_price_2k?: number | null
+  image_price_4k?: number | null
+  claude_code_only?: boolean
+  fallback_group_id?: number | null
 }
 
 export interface UpdateGroupRequest {
@@ -307,6 +319,15 @@ export interface UpdateGroupRequest {
   rate_multiplier?: number
   is_exclusive?: boolean
   status?: 'active' | 'inactive'
+  subscription_type?: SubscriptionType
+  daily_limit_usd?: number | null
+  weekly_limit_usd?: number | null
+  monthly_limit_usd?: number | null
+  image_price_1k?: number | null
+  image_price_2k?: number | null
+  image_price_4k?: number | null
+  claude_code_only?: boolean
+  fallback_group_id?: number | null
 }
 
 // ==================== Account & Proxy Types ====================
@@ -576,6 +597,9 @@ export interface UsageLog {
   image_count: number
   image_size: string | null
 
+  // User-Agent
+  user_agent: string | null
+
   created_at: string
 
   user?: User

frontend/src/views/HomeView.vue

@@ -61,7 +61,7 @@
           <!-- Login / Dashboard Button -->
           <router-link
             v-if="isAuthenticated"
-            to="/dashboard"
+            :to="dashboardPath"
             class="inline-flex items-center gap-1.5 rounded-full bg-gray-900 py-1 pl-1 pr-2.5 transition-colors hover:bg-gray-800 dark:bg-gray-800 dark:hover:bg-gray-700"
           >
             <span
@@ -114,7 +114,7 @@
             <!-- CTA Button -->
             <div>
               <router-link
-                :to="isAuthenticated ? '/dashboard' : '/login'"
+                :to="isAuthenticated ? dashboardPath : '/login'"
                 class="btn btn-primary px-8 py-3 text-base shadow-lg shadow-primary-500/30"
               >
                 {{ isAuthenticated ? t('home.goToDashboard') : t('home.getStarted') }}
@@ -416,6 +416,8 @@ const githubUrl = 'https://github.com/Wei-Shaw/sub2api'
 
 // Auth state
 const isAuthenticated = computed(() => authStore.isAuthenticated)
+const isAdmin = computed(() => authStore.isAdmin)
+const dashboardPath = computed(() => isAdmin.value ? '/admin/dashboard' : '/dashboard')
 const userInitial = computed(() => {
   const user = authStore.user
   if (!user || !user.email) return ''

frontend/src/views/admin/GroupsView.vue

@@ -403,6 +403,62 @@
           </div>
         </div>
 
+        <!-- Claude Code 客户端限制（仅 anthropic 平台） -->
+        <div v-if="createForm.platform === 'anthropic'" class="border-t pt-4">
+          <div class="mb-1.5 flex items-center gap-1">
+            <label class="text-sm font-medium text-gray-700 dark:text-gray-300">
+              {{ t('admin.groups.claudeCode.title') }}
+            </label>
+            <!-- Help Tooltip -->
+            <div class="group relative inline-flex">
+              <Icon
+                name="questionCircle"
+                size="sm"
+                :stroke-width="2"
+                class="cursor-help text-gray-400 transition-colors hover:text-primary-500 dark:text-gray-500 dark:hover:text-primary-400"
+              />
+              <div class="pointer-events-none absolute bottom-full left-0 z-50 mb-2 w-72 opacity-0 transition-all duration-200 group-hover:pointer-events-auto group-hover:opacity-100">
+                <div class="rounded-lg bg-gray-900 p-3 text-white shadow-lg dark:bg-gray-800">
+                  <p class="text-xs leading-relaxed text-gray-300">
+                    {{ t('admin.groups.claudeCode.tooltip') }}
+                  </p>
+                  <div class="absolute -bottom-1.5 left-3 h-3 w-3 rotate-45 bg-gray-900 dark:bg-gray-800"></div>
+                </div>
+              </div>
+            </div>
+          </div>
+          <div class="flex items-center gap-3">
+            <button
+              type="button"
+              @click="createForm.claude_code_only = !createForm.claude_code_only"
+              :class="[
+                'relative inline-flex h-6 w-11 items-center rounded-full transition-colors',
+                createForm.claude_code_only ? 'bg-primary-500' : 'bg-gray-300 dark:bg-dark-600'
+              ]"
+            >
+              <span
+                :class="[
+                  'inline-block h-4 w-4 transform rounded-full bg-white shadow transition-transform',
+                  createForm.claude_code_only ? 'translate-x-6' : 'translate-x-1'
+                ]"
+              />
+            </button>
+            <span class="text-sm text-gray-500 dark:text-gray-400">
+              {{ createForm.claude_code_only ? t('admin.groups.claudeCode.enabled') : t('admin.groups.claudeCode.disabled') }}
+            </span>
+          </div>
+          <!-- 降级分组选择（仅当启用 claude_code_only 时显示） -->
+          <div v-if="createForm.claude_code_only" class="mt-3">
+            <label class="input-label">{{ t('admin.groups.claudeCode.fallbackGroup') }}</label>
+            <Select
+              v-model="createForm.fallback_group_id"
+              :options="fallbackGroupOptions"
+              :placeholder="t('admin.groups.claudeCode.noFallback')"
+            />
+            <p class="input-hint">{{ t('admin.groups.claudeCode.fallbackHint') }}</p>
+          </div>
+        </div>
+
       </form>
 
       <template #footer>
@@ -648,6 +704,62 @@
           </div>
         </div>
 
+        <!-- Claude Code 客户端限制（仅 anthropic 平台） -->
+        <div v-if="editForm.platform === 'anthropic'" class="border-t pt-4">
+          <div class="mb-1.5 flex items-center gap-1">
+            <label class="text-sm font-medium text-gray-700 dark:text-gray-300">
+              {{ t('admin.groups.claudeCode.title') }}
+            </label>
+            <!-- Help Tooltip -->
+            <div class="group relative inline-flex">
+              <Icon
+                name="questionCircle"
+                size="sm"
+                :stroke-width="2"
+                class="cursor-help text-gray-400 transition-colors hover:text-primary-500 dark:text-gray-500 dark:hover:text-primary-400"
+              />
+              <div class="pointer-events-none absolute bottom-full left-0 z-50 mb-2 w-72 opacity-0 transition-all duration-200 group-hover:pointer-events-auto group-hover:opacity-100">
+                <div class="rounded-lg bg-gray-900 p-3 text-white shadow-lg dark:bg-gray-800">
+                  <p class="text-xs leading-relaxed text-gray-300">
+                    {{ t('admin.groups.claudeCode.tooltip') }}
+                  </p>
+                  <div class="absolute -bottom-1.5 left-3 h-3 w-3 rotate-45 bg-gray-900 dark:bg-gray-800"></div>
+                </div>
+              </div>
+            </div>
+          </div>
+          <div class="flex items-center gap-3">
+            <button
+              type="button"
+              @click="editForm.claude_code_only = !editForm.claude_code_only"
+              :class="[
+                'relative inline-flex h-6 w-11 items-center rounded-full transition-colors',
+                editForm.claude_code_only ? 'bg-primary-500' : 'bg-gray-300 dark:bg-dark-600'
+              ]"
+            >
+              <span
+                :class="[
+                  'inline-block h-4 w-4 transform rounded-full bg-white shadow transition-transform',
+                  editForm.claude_code_only ? 'translate-x-6' : 'translate-x-1'
+                ]"
+              />
+            </button>
+            <span class="text-sm text-gray-500 dark:text-gray-400">
+              {{ editForm.claude_code_only ? t('admin.groups.claudeCode.enabled') : t('admin.groups.claudeCode.disabled') }}
+            </span>
+          </div>
+          <!-- 降级分组选择（仅当启用 claude_code_only 时显示） -->
+          <div v-if="editForm.claude_code_only" class="mt-3">
+            <label class="input-label">{{ t('admin.groups.claudeCode.fallbackGroup') }}</label>
+            <Select
+              v-model="editForm.fallback_group_id"
+              :options="fallbackGroupOptionsForEdit"
+              :placeholder="t('admin.groups.claudeCode.noFallback')"
+            />
+            <p class="input-hint">{{ t('admin.groups.claudeCode.fallbackHint') }}</p>
+          </div>
+        </div>
+
       </form>
 
       <template #footer>
@@ -774,6 +886,35 @@ const subscriptionTypeOptions = computed(() => [
   { value: 'subscription', label: t('admin.groups.subscription.subscription') }
 ])
 
+// 降级分组选项（创建时）- 仅包含 anthropic 平台且未启用 claude_code_only 的分组
+const fallbackGroupOptions = computed(() => {
+  const options: { value: number | null; label: string }[] = [
+    { value: null, label: t('admin.groups.claudeCode.noFallback') }
+  ]
+  const eligibleGroups = groups.value.filter(
+    (g) => g.platform === 'anthropic' && !g.claude_code_only && g.status === 'active'
+  )
+  eligibleGroups.forEach((g) => {
+    options.push({ value: g.id, label: g.name })
+  })
+  return options
+})
+
+// 降级分组选项（编辑时）- 排除自身
+const fallbackGroupOptionsForEdit = computed(() => {
+  const options: { value: number | null; label: string }[] = [
+    { value: null, label: t('admin.groups.claudeCode.noFallback') }
+  ]
+  const currentId = editingGroup.value?.id
+  const eligibleGroups = groups.value.filter(
+    (g) => g.platform === 'anthropic' && !g.claude_code_only && g.status === 'active' && g.id !== currentId
+  )
+  eligibleGroups.forEach((g) => {
+    options.push({ value: g.id, label: g.name })
+  })
+  return options
+})
+
 const groups = ref<Group[]>([])
 const loading = ref(false)
 const searchQuery = ref('')
@@ -821,7 +962,10 @@ const createForm = reactive({
   // 图片生成计费配置（仅 antigravity 平台使用）
   image_price_1k: null as number | null,
   image_price_2k: null as number | null,
-  image_price_4k: null as number | null
+  image_price_4k: null as number | null,
+  // Claude Code 客户端限制（仅 anthropic 平台使用）
+  claude_code_only: false,
+  fallback_group_id: null as number | null
 })
 
 const editForm = reactive({
@@ -838,7 +982,10 @@ const editForm = reactive({
   // 图片生成计费配置（仅 antigravity 平台使用）
   image_price_1k: null as number | null,
   image_price_2k: null as number | null,
-  image_price_4k: null as number | null
+  image_price_4k: null as number | null,
+  // Claude Code 客户端限制（仅 anthropic 平台使用）
+  claude_code_only: false,
+  fallback_group_id: null as number | null
 })
 
 // 根据分组类型返回不同的删除确认消息
@@ -908,6 +1055,8 @@ const closeCreateModal = () => {
   createForm.image_price_1k = null
   createForm.image_price_2k = null
   createForm.image_price_4k = null
+  createForm.claude_code_only = false
+  createForm.fallback_group_id = null
 }
 
 const handleCreateGroup = async () => {
@@ -949,6 +1098,8 @@ const handleEdit = (group: Group) => {
   editForm.image_price_1k = group.image_price_1k
   editForm.image_price_2k = group.image_price_2k
   editForm.image_price_4k = group.image_price_4k
+  editForm.claude_code_only = group.claude_code_only || false
+  editForm.fallback_group_id = group.fallback_group_id
   showEditModal.value = true
 }
 
@@ -966,7 +1117,12 @@ const handleUpdateGroup = async () => {
 
   submitting.value = true
   try {
-    await adminAPI.groups.update(editingGroup.value.id, editForm)
+    // 转换 fallback_group_id: null -> 0 (后端使用 0 表示清除)
+    const payload = {
+      ...editForm,
+      fallback_group_id: editForm.fallback_group_id === null ? 0 : editForm.fallback_group_id
+    }
+    await adminAPI.groups.update(editingGroup.value.id, payload)
     appStore.showSuccess(t('admin.groups.groupUpdated'))
     closeEditModal()
     loadGroups()

frontend/src/views/admin/ProxiesView.vue

@@ -85,6 +85,14 @@
             </span>
           </template>
 
+          <template #cell-account_count="{ value }">
+            <span
+              class="inline-flex items-center rounded bg-gray-100 px-2 py-0.5 text-xs font-medium text-gray-800 dark:bg-dark-600 dark:text-gray-300"
+            >
+              {{ t('admin.groups.accountsCount', { count: value || 0 }) }}
+            </span>
+          </template>
+
           <template #cell-actions="{ row }">
             <div class="flex items-center gap-1">
               <button
@@ -534,6 +542,7 @@ const columns = computed<Column[]>(() => [
   { key: 'name', label: t('admin.proxies.columns.name'), sortable: true },
   { key: 'protocol', label: t('admin.proxies.columns.protocol'), sortable: true },
   { key: 'address', label: t('admin.proxies.columns.address'), sortable: false },
+  { key: 'account_count', label: t('admin.proxies.columns.accounts'), sortable: true },
   { key: 'status', label: t('admin.proxies.columns.status'), sortable: true },
   { key: 'actions', label: t('admin.proxies.columns.actions'), sortable: false }
 ])

frontend/src/views/admin/UsageView.vue

@@ -96,7 +96,7 @@ const exportToExcel = async () => {
         t('admin.usage.cacheReadCost'), t('admin.usage.cacheCreationCost'),
         t('usage.rate'), t('usage.original'), t('usage.billed'),
         t('usage.billingType'), t('usage.firstToken'), t('usage.duration'),
-        t('admin.usage.requestId')
+        t('admin.usage.requestId'), t('usage.userAgent')
       ]
       const rows = all.map(log => [
         log.created_at,
@@ -120,7 +120,8 @@ const exportToExcel = async () => {
         log.billing_type === 1 ? t('usage.subscription') : t('usage.balance'),
         log.first_token_ms ?? '',
         log.duration_ms,
-        log.request_id || ''
+        log.request_id || '',
+        log.user_agent || ''
       ])
       const ws = XLSX.utils.aoa_to_sheet([headers, ...rows])
       const wb = XLSX.utils.book_new()

frontend/src/views/user/UsageView.vue

@@ -308,6 +308,11 @@
             }}</span>
           </template>
 
+          <template #cell-user_agent="{ row }">
+            <span v-if="row.user_agent" class="text-sm text-gray-600 dark:text-gray-400 max-w-[150px] truncate block" :title="row.user_agent">{{ formatUserAgent(row.user_agent) }}</span>
+            <span v-else class="text-sm text-gray-400 dark:text-gray-500">-</span>
+          </template>
+
           <template #empty>
             <EmptyState :message="t('usage.noRecords')" />
           </template>
@@ -480,7 +485,8 @@ const columns = computed<Column[]>(() => [
   { key: 'billing_type', label: t('usage.billingType'), sortable: false },
   { key: 'first_token', label: t('usage.firstToken'), sortable: false },
   { key: 'duration', label: t('usage.duration'), sortable: false },
-  { key: 'created_at', label: t('usage.time'), sortable: true }
+  { key: 'created_at', label: t('usage.time'), sortable: true },
+  { key: 'user_agent', label: t('usage.userAgent'), sortable: false }
 ])
 
 const usageLogs = ref<UsageLog[]>([])
@@ -545,6 +551,19 @@ const formatDuration = (ms: number): string => {
   return `${(ms / 1000).toFixed(2)}s`
 }
 
+const formatUserAgent = (ua: string): string => {
+  // 提取主要客户端标识
+  if (ua.includes('claude-cli')) return ua.match(/claude-cli\/[\d.]+/)?.[0] || 'Claude CLI'
+  if (ua.includes('Cursor')) return 'Cursor'
+  if (ua.includes('VSCode') || ua.includes('vscode')) return 'VS Code'
+  if (ua.includes('Continue')) return 'Continue'
+  if (ua.includes('Cline')) return 'Cline'
+  if (ua.includes('OpenAI')) return 'OpenAI SDK'
+  if (ua.includes('anthropic')) return 'Anthropic SDK'
+  // 截断过长的 UA
+  return ua.length > 30 ? ua.substring(0, 30) + '...' : ua
+}
+
 const formatTokens = (value: number): string => {
   if (value >= 1_000_000_000) {
     return `${(value / 1_000_000_000).toFixed(2)}B`