fix(billing): 修复 OpenAI fast 档位计费并补齐展示

- 打通 service_tier 在 OpenAI HTTP、WS、passthrough 与 usage 记录中的传递 - 修正 priority/flex 计费逻辑，并将 fast 归一化为 priority - 在用户端和管理端补齐服务档位与计费明细展示 - 补齐前后端测试，并修复 WS 限流信号重复持久化导致的全量回归失败 Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-30 06:23:07 +00:00 · 2026-03-08 23:22:28 +08:00
parent bcb6444f89
commit 87f4ed591e
29 changed files with 1417 additions and 47 deletions
--- a/backend/internal/handler/dto/mappers.go
+++ b/backend/internal/handler/dto/mappers.go
@@ -475,6 +475,7 @@ func usageLogFromServiceUser(l *service.UsageLog) UsageLog {
 		AccountID:             l.AccountID,
 		RequestID:             l.RequestID,
 		Model:                 l.Model,
+		ServiceTier:           l.ServiceTier,
 		ReasoningEffort:       l.ReasoningEffort,
 		GroupID:               l.GroupID,
 		SubscriptionID:        l.SubscriptionID,
--- a/backend/internal/handler/dto/mappers_usage_test.go
+++ b/backend/internal/handler/dto/mappers_usage_test.go
@@ -71,3 +71,29 @@ func TestRequestTypeStringPtrNil(t *testing.T) {
 	t.Parallel()
 	require.Nil(t, requestTypeStringPtr(nil))
 }
+
+func TestUsageLogFromService_IncludesServiceTierForUserAndAdmin(t *testing.T) {
+	t.Parallel()
+
+	serviceTier := "priority"
+	log := &service.UsageLog{
+		RequestID:             "req_3",
+		Model:                 "gpt-5.4",
+		ServiceTier:           &serviceTier,
+		AccountRateMultiplier: f64Ptr(1.5),
+	}
+
+	userDTO := UsageLogFromService(log)
+	adminDTO := UsageLogFromServiceAdmin(log)
+
+	require.NotNil(t, userDTO.ServiceTier)
+	require.Equal(t, serviceTier, *userDTO.ServiceTier)
+	require.NotNil(t, adminDTO.ServiceTier)
+	require.Equal(t, serviceTier, *adminDTO.ServiceTier)
+	require.NotNil(t, adminDTO.AccountRateMultiplier)
+	require.InDelta(t, 1.5, *adminDTO.AccountRateMultiplier, 1e-12)
+}
+
+func f64Ptr(value float64) *float64 {
+	return &value
+}
--- a/backend/internal/handler/dto/types.go
+++ b/backend/internal/handler/dto/types.go
@@ -315,6 +315,8 @@ type UsageLog struct {
 	AccountID int64  `json:"account_id"`
 	RequestID string `json:"request_id"`
 	Model     string `json:"model"`
+	// ServiceTier records the OpenAI service tier used for billing, e.g. "priority" / "flex".
+	ServiceTier *string `json:"service_tier,omitempty"`
 	// ReasoningEffort is the request's reasoning effort level (OpenAI Responses API).
 	// nil means not provided / not applicable.
 	ReasoningEffort *string `json:"reasoning_effort,omitempty"`
--- a/backend/internal/repository/usage_log_repo.go
+++ b/backend/internal/repository/usage_log_repo.go
@@ -22,7 +22,7 @@ import (
 	"github.com/lib/pq"
 )

-const usageLogSelectColumns = "id, user_id, api_key_id, account_id, request_id, model, group_id, subscription_id, input_tokens, output_tokens, cache_creation_tokens, cache_read_tokens, cache_creation_5m_tokens, cache_creation_1h_tokens, input_cost, output_cost, cache_creation_cost, cache_read_cost, total_cost, actual_cost, rate_multiplier, account_rate_multiplier, billing_type, request_type, stream, openai_ws_mode, duration_ms, first_token_ms, user_agent, ip_address, image_count, image_size, media_type, reasoning_effort, cache_ttl_overridden, created_at"
+const usageLogSelectColumns = "id, user_id, api_key_id, account_id, request_id, model, group_id, subscription_id, input_tokens, output_tokens, cache_creation_tokens, cache_read_tokens, cache_creation_5m_tokens, cache_creation_1h_tokens, input_cost, output_cost, cache_creation_cost, cache_read_cost, total_cost, actual_cost, rate_multiplier, account_rate_multiplier, billing_type, request_type, stream, openai_ws_mode, duration_ms, first_token_ms, user_agent, ip_address, image_count, image_size, media_type, service_tier, reasoning_effort, cache_ttl_overridden, created_at"

 // dateFormatWhitelist 将 granularity 参数映射为 PostgreSQL TO_CHAR 格式字符串，防止外部输入直接拼入 SQL
 var dateFormatWhitelist = map[string]string{
@@ -135,6 +135,7 @@ func (r *usageLogRepository) Create(ctx context.Context, log *service.UsageLog)
 			image_count,
 			image_size,
 			media_type,
+			service_tier,
 			reasoning_effort,
 			cache_ttl_overridden,
 			created_at
@@ -144,7 +145,7 @@ func (r *usageLogRepository) Create(ctx context.Context, log *service.UsageLog)
 			$8, $9, $10, $11,
 			$12, $13,
 			$14, $15, $16, $17, $18, $19,
-			$20, $21, $22, $23, $24, $25, $26, $27, $28, $29, $30, $31, $32, $33, $34, $35
+			$20, $21, $22, $23, $24, $25, $26, $27, $28, $29, $30, $31, $32, $33, $34, $35, $36
 		)
 		ON CONFLICT (request_id, api_key_id) DO NOTHING
 		RETURNING id, created_at
@@ -158,6 +159,7 @@ func (r *usageLogRepository) Create(ctx context.Context, log *service.UsageLog)
 	ipAddress := nullString(log.IPAddress)
 	imageSize := nullString(log.ImageSize)
 	mediaType := nullString(log.MediaType)
+	serviceTier := nullString(log.ServiceTier)
 	reasoningEffort := nullString(log.ReasoningEffort)

 	var requestIDArg any
@@ -198,6 +200,7 @@ func (r *usageLogRepository) Create(ctx context.Context, log *service.UsageLog)
 		log.ImageCount,
 		imageSize,
 		mediaType,
+		serviceTier,
 		reasoningEffort,
 		log.CacheTTLOverridden,
 		createdAt,
@@ -2505,6 +2508,7 @@ func scanUsageLog(scanner interface{ Scan(...any) error }) (*service.UsageLog, e
 		imageCount            int
 		imageSize             sql.NullString
 		mediaType             sql.NullString
+		serviceTier           sql.NullString
 		reasoningEffort       sql.NullString
 		cacheTTLOverridden    bool
 		createdAt             time.Time
@@ -2544,6 +2548,7 @@ func scanUsageLog(scanner interface{ Scan(...any) error }) (*service.UsageLog, e
 		&imageCount,
 		&imageSize,
 		&mediaType,
+		&serviceTier,
 		&reasoningEffort,
 		&cacheTTLOverridden,
 		&createdAt,
@@ -2614,6 +2619,9 @@ func scanUsageLog(scanner interface{ Scan(...any) error }) (*service.UsageLog, e
 	if mediaType.Valid {
 		log.MediaType = &mediaType.String
 	}
+	if serviceTier.Valid {
+		log.ServiceTier = &serviceTier.String
+	}
 	if reasoningEffort.Valid {
 		log.ReasoningEffort = &reasoningEffort.String
 	}
--- a/backend/internal/repository/usage_log_repo_request_type_test.go
+++ b/backend/internal/repository/usage_log_repo_request_type_test.go
@@ -71,6 +71,7 @@ func TestUsageLogRepositoryCreateSyncRequestTypeAndLegacyFields(t *testing.T) {
 			log.ImageCount,
 			sqlmock.AnyArg(), // image_size
 			sqlmock.AnyArg(), // media_type
+			sqlmock.AnyArg(), // service_tier
 			sqlmock.AnyArg(), // reasoning_effort
 			log.CacheTTLOverridden,
 			createdAt,
@@ -81,12 +82,76 @@ func TestUsageLogRepositoryCreateSyncRequestTypeAndLegacyFields(t *testing.T) {
 	require.NoError(t, err)
 	require.True(t, inserted)
 	require.Equal(t, int64(99), log.ID)
+	require.Nil(t, log.ServiceTier)
 	require.Equal(t, service.RequestTypeWSV2, log.RequestType)
 	require.True(t, log.Stream)
 	require.True(t, log.OpenAIWSMode)
 	require.NoError(t, mock.ExpectationsWereMet())
 }

+func TestUsageLogRepositoryCreate_PersistsServiceTier(t *testing.T) {
+	db, mock := newSQLMock(t)
+	repo := &usageLogRepository{sql: db}
+
+	createdAt := time.Date(2025, 1, 2, 12, 0, 0, 0, time.UTC)
+	serviceTier := "priority"
+	log := &service.UsageLog{
+		UserID:      1,
+		APIKeyID:    2,
+		AccountID:   3,
+		RequestID:   "req-service-tier",
+		Model:       "gpt-5.4",
+		ServiceTier: &serviceTier,
+		CreatedAt:   createdAt,
+	}
+
+	mock.ExpectQuery("INSERT INTO usage_logs").
+		WithArgs(
+			log.UserID,
+			log.APIKeyID,
+			log.AccountID,
+			log.RequestID,
+			log.Model,
+			sqlmock.AnyArg(),
+			sqlmock.AnyArg(),
+			log.InputTokens,
+			log.OutputTokens,
+			log.CacheCreationTokens,
+			log.CacheReadTokens,
+			log.CacheCreation5mTokens,
+			log.CacheCreation1hTokens,
+			log.InputCost,
+			log.OutputCost,
+			log.CacheCreationCost,
+			log.CacheReadCost,
+			log.TotalCost,
+			log.ActualCost,
+			log.RateMultiplier,
+			log.AccountRateMultiplier,
+			log.BillingType,
+			int16(service.RequestTypeSync),
+			false,
+			false,
+			sqlmock.AnyArg(),
+			sqlmock.AnyArg(),
+			sqlmock.AnyArg(),
+			sqlmock.AnyArg(),
+			log.ImageCount,
+			sqlmock.AnyArg(),
+			sqlmock.AnyArg(),
+			serviceTier,
+			sqlmock.AnyArg(),
+			log.CacheTTLOverridden,
+			createdAt,
+		).
+		WillReturnRows(sqlmock.NewRows([]string{"id", "created_at"}).AddRow(int64(100), createdAt))
+
+	inserted, err := repo.Create(context.Background(), log)
+	require.NoError(t, err)
+	require.True(t, inserted)
+	require.NoError(t, mock.ExpectationsWereMet())
+}
+
 func TestUsageLogRepositoryListWithFiltersRequestTypePriority(t *testing.T) {
 	db, mock := newSQLMock(t)
 	repo := &usageLogRepository{sql: db}
@@ -280,11 +345,14 @@ func TestScanUsageLogRequestTypeAndLegacyFallback(t *testing.T) {
 			0,
 			sql.NullString{},
 			sql.NullString{},
+			sql.NullString{Valid: true, String: "priority"},
 			sql.NullString{},
 			false,
 			now,
 		}})
 		require.NoError(t, err)
+		require.NotNil(t, log.ServiceTier)
+		require.Equal(t, "priority", *log.ServiceTier)
 		require.Equal(t, service.RequestTypeWSV2, log.RequestType)
 		require.True(t, log.Stream)
 		require.True(t, log.OpenAIWSMode)
@@ -316,13 +384,53 @@ func TestScanUsageLogRequestTypeAndLegacyFallback(t *testing.T) {
 			0,
 			sql.NullString{},
 			sql.NullString{},
+			sql.NullString{Valid: true, String: "flex"},
 			sql.NullString{},
 			false,
 			now,
 		}})
 		require.NoError(t, err)
+		require.NotNil(t, log.ServiceTier)
+		require.Equal(t, "flex", *log.ServiceTier)
 		require.Equal(t, service.RequestTypeStream, log.RequestType)
 		require.True(t, log.Stream)
 		require.False(t, log.OpenAIWSMode)
 	})
+
+	t.Run("service_tier_is_scanned", func(t *testing.T) {
+		now := time.Now().UTC()
+		log, err := scanUsageLog(usageLogScannerStub{values: []any{
+			int64(3),
+			int64(12),
+			int64(22),
+			int64(32),
+			sql.NullString{Valid: true, String: "req-3"},
+			"gpt-5.4",
+			sql.NullInt64{},
+			sql.NullInt64{},
+			1, 2, 3, 4, 5, 6,
+			0.1, 0.2, 0.3, 0.4, 1.0, 0.9,
+			1.0,
+			sql.NullFloat64{},
+			int16(service.BillingTypeBalance),
+			int16(service.RequestTypeSync),
+			false,
+			false,
+			sql.NullInt64{},
+			sql.NullInt64{},
+			sql.NullString{},
+			sql.NullString{},
+			0,
+			sql.NullString{},
+			sql.NullString{},
+			sql.NullString{Valid: true, String: "priority"},
+			sql.NullString{},
+			false,
+			now,
+		}})
+		require.NoError(t, err)
+		require.NotNil(t, log.ServiceTier)
+		require.Equal(t, "priority", *log.ServiceTier)
+	})
+
 }
--- a/backend/internal/server/api_contract_test.go
+++ b/backend/internal/server/api_contract_test.go
@@ -210,8 +210,10 @@ func TestAPIContracts(t *testing.T) {
 							"sora_video_price_per_request": null,
 							"sora_video_price_per_request_hd": null,
 							"claude_code_only": false,
+						"allow_messages_dispatch": false,
 						"fallback_group_id": null,
 						"fallback_group_id_on_invalid_request": null,
+						"allow_messages_dispatch": false,
 						"created_at": "2025-01-02T03:04:05Z",
 						"updated_at": "2025-01-02T03:04:05Z"
 					}
--- a/backend/internal/service/billing_service.go
+++ b/backend/internal/service/billing_service.go
@@ -43,16 +43,19 @@ type BillingCache interface {

 // ModelPricing 模型价格配置（per-token价格，与LiteLLM格式一致）
 type ModelPricing struct {
-	InputPricePerToken          float64 // 每token输入价格 (USD)
-	OutputPricePerToken         float64 // 每token输出价格 (USD)
-	CacheCreationPricePerToken  float64 // 缓存创建每token价格 (USD)
-	CacheReadPricePerToken      float64 // 缓存读取每token价格 (USD)
-	CacheCreation5mPrice        float64 // 5分钟缓存创建每token价格 (USD)
-	CacheCreation1hPrice        float64 // 1小时缓存创建每token价格 (USD)
-	SupportsCacheBreakdown      bool    // 是否支持详细的缓存分类
-	LongContextInputThreshold   int     // 超过阈值后按整次会话提升输入价格
-	LongContextInputMultiplier  float64 // 长上下文整次会话输入倍率
-	LongContextOutputMultiplier float64 // 长上下文整次会话输出倍率
+	InputPricePerToken             float64 // 每token输入价格 (USD)
+	InputPricePerTokenPriority     float64 // priority service tier 下每token输入价格 (USD)
+	OutputPricePerToken            float64 // 每token输出价格 (USD)
+	OutputPricePerTokenPriority    float64 // priority service tier 下每token输出价格 (USD)
+	CacheCreationPricePerToken     float64 // 缓存创建每token价格 (USD)
+	CacheReadPricePerToken         float64 // 缓存读取每token价格 (USD)
+	CacheReadPricePerTokenPriority float64 // priority service tier 下缓存读取每token价格 (USD)
+	CacheCreation5mPrice           float64 // 5分钟缓存创建每token价格 (USD)
+	CacheCreation1hPrice           float64 // 1小时缓存创建每token价格 (USD)
+	SupportsCacheBreakdown         bool    // 是否支持详细的缓存分类
+	LongContextInputThreshold      int     // 超过阈值后按整次会话提升输入价格
+	LongContextInputMultiplier     float64 // 长上下文整次会话输入倍率
+	LongContextOutputMultiplier    float64 // 长上下文整次会话输出倍率
 }

 const (
@@ -61,6 +64,28 @@ const (
 	openAIGPT54LongContextOutputMultiplier = 1.5
 )

+func normalizeBillingServiceTier(serviceTier string) string {
+	return strings.ToLower(strings.TrimSpace(serviceTier))
+}
+
+func usePriorityServiceTierPricing(serviceTier string, pricing *ModelPricing) bool {
+	if pricing == nil || normalizeBillingServiceTier(serviceTier) != "priority" {
+		return false
+	}
+	return pricing.InputPricePerTokenPriority > 0 || pricing.OutputPricePerTokenPriority > 0 || pricing.CacheReadPricePerTokenPriority > 0
+}
+
+func serviceTierCostMultiplier(serviceTier string) float64 {
+	switch normalizeBillingServiceTier(serviceTier) {
+	case "priority":
+		return 2.0
+	case "flex":
+		return 0.5
+	default:
+		return 1.0
+	}
+}
+
 // UsageTokens 使用的token数量
 type UsageTokens struct {
 	InputTokens           int
@@ -173,30 +198,60 @@ func (s *BillingService) initFallbackPricing() {

 	// OpenAI GPT-5.1（本地兜底，防止动态定价不可用时拒绝计费）
 	s.fallbackPrices["gpt-5.1"] = &ModelPricing{
-		InputPricePerToken:         1.25e-6, // $1.25 per MTok
-		OutputPricePerToken:        10e-6,   // $10 per MTok
-		CacheCreationPricePerToken: 1.25e-6, // $1.25 per MTok
-		CacheReadPricePerToken:     0.125e-6,
-		SupportsCacheBreakdown:     false,
+		InputPricePerToken:             1.25e-6, // $1.25 per MTok
+		InputPricePerTokenPriority:     2.5e-6,  // $2.5 per MTok
+		OutputPricePerToken:            10e-6,   // $10 per MTok
+		OutputPricePerTokenPriority:    20e-6,   // $20 per MTok
+		CacheCreationPricePerToken:     1.25e-6, // $1.25 per MTok
+		CacheReadPricePerToken:         0.125e-6,
+		CacheReadPricePerTokenPriority: 0.25e-6,
+		SupportsCacheBreakdown:         false,
 	}
 	// OpenAI GPT-5.4（业务指定价格）
 	s.fallbackPrices["gpt-5.4"] = &ModelPricing{
-		InputPricePerToken:          2.5e-6,  // $2.5 per MTok
-		OutputPricePerToken:         15e-6,   // $15 per MTok
-		CacheCreationPricePerToken:  2.5e-6,  // $2.5 per MTok
-		CacheReadPricePerToken:      0.25e-6, // $0.25 per MTok
-		SupportsCacheBreakdown:      false,
-		LongContextInputThreshold:   openAIGPT54LongContextInputThreshold,
-		LongContextInputMultiplier:  openAIGPT54LongContextInputMultiplier,
-		LongContextOutputMultiplier: openAIGPT54LongContextOutputMultiplier,
+		InputPricePerToken:             2.5e-6,  // $2.5 per MTok
+		InputPricePerTokenPriority:     5e-6,    // $5 per MTok
+		OutputPricePerToken:            15e-6,   // $15 per MTok
+		OutputPricePerTokenPriority:    30e-6,   // $30 per MTok
+		CacheCreationPricePerToken:     2.5e-6,  // $2.5 per MTok
+		CacheReadPricePerToken:         0.25e-6, // $0.25 per MTok
+		CacheReadPricePerTokenPriority: 0.5e-6,  // $0.5 per MTok
+		SupportsCacheBreakdown:         false,
+		LongContextInputThreshold:      openAIGPT54LongContextInputThreshold,
+		LongContextInputMultiplier:     openAIGPT54LongContextInputMultiplier,
+		LongContextOutputMultiplier:    openAIGPT54LongContextOutputMultiplier,
+	}
+	// OpenAI GPT-5.2（本地兜底）
+	s.fallbackPrices["gpt-5.2"] = &ModelPricing{
+		InputPricePerToken:             1.75e-6,
+		InputPricePerTokenPriority:     3.5e-6,
+		OutputPricePerToken:            14e-6,
+		OutputPricePerTokenPriority:    28e-6,
+		CacheCreationPricePerToken:     1.75e-6,
+		CacheReadPricePerToken:         0.175e-6,
+		CacheReadPricePerTokenPriority: 0.35e-6,
+		SupportsCacheBreakdown:         false,
 	}
 	// Codex 族兜底统一按 GPT-5.1 Codex 价格计费
 	s.fallbackPrices["gpt-5.1-codex"] = &ModelPricing{
-		InputPricePerToken:         1.5e-6, // $1.5 per MTok
-		OutputPricePerToken:        12e-6,  // $12 per MTok
-		CacheCreationPricePerToken: 1.5e-6, // $1.5 per MTok
-		CacheReadPricePerToken:     0.15e-6,
-		SupportsCacheBreakdown:     false,
+		InputPricePerToken:             1.5e-6, // $1.5 per MTok
+		InputPricePerTokenPriority:     3e-6,   // $3 per MTok
+		OutputPricePerToken:            12e-6,  // $12 per MTok
+		OutputPricePerTokenPriority:    24e-6,  // $24 per MTok
+		CacheCreationPricePerToken:     1.5e-6, // $1.5 per MTok
+		CacheReadPricePerToken:         0.15e-6,
+		CacheReadPricePerTokenPriority: 0.3e-6,
+		SupportsCacheBreakdown:         false,
+	}
+	s.fallbackPrices["gpt-5.2-codex"] = &ModelPricing{
+		InputPricePerToken:             1.75e-6,
+		InputPricePerTokenPriority:     3.5e-6,
+		OutputPricePerToken:            14e-6,
+		OutputPricePerTokenPriority:    28e-6,
+		CacheCreationPricePerToken:     1.75e-6,
+		CacheReadPricePerToken:         0.175e-6,
+		CacheReadPricePerTokenPriority: 0.35e-6,
+		SupportsCacheBreakdown:         false,
 	}
 	s.fallbackPrices["gpt-5.3-codex"] = s.fallbackPrices["gpt-5.1-codex"]
 }
@@ -241,6 +296,10 @@ func (s *BillingService) getFallbackPricing(model string) *ModelPricing {
 		switch normalized {
 		case "gpt-5.4":
 			return s.fallbackPrices["gpt-5.4"]
+		case "gpt-5.2":
+			return s.fallbackPrices["gpt-5.2"]
+		case "gpt-5.2-codex":
+			return s.fallbackPrices["gpt-5.2-codex"]
 		case "gpt-5.3-codex":
 			return s.fallbackPrices["gpt-5.3-codex"]
 		case "gpt-5.1-codex", "gpt-5.1-codex-max", "gpt-5.1-codex-mini", "codex-mini-latest":
@@ -269,16 +328,19 @@ func (s *BillingService) GetModelPricing(model string) (*ModelPricing, error) {
 			price1h := litellmPricing.CacheCreationInputTokenCostAbove1hr
 			enableBreakdown := price1h > 0 && price1h > price5m
 			return s.applyModelSpecificPricingPolicy(model, &ModelPricing{
-				InputPricePerToken:          litellmPricing.InputCostPerToken,
-				OutputPricePerToken:         litellmPricing.OutputCostPerToken,
-				CacheCreationPricePerToken:  litellmPricing.CacheCreationInputTokenCost,
-				CacheReadPricePerToken:      litellmPricing.CacheReadInputTokenCost,
-				CacheCreation5mPrice:        price5m,
-				CacheCreation1hPrice:        price1h,
-				SupportsCacheBreakdown:      enableBreakdown,
-				LongContextInputThreshold:   litellmPricing.LongContextInputTokenThreshold,
-				LongContextInputMultiplier:  litellmPricing.LongContextInputCostMultiplier,
-				LongContextOutputMultiplier: litellmPricing.LongContextOutputCostMultiplier,
+				InputPricePerToken:             litellmPricing.InputCostPerToken,
+				InputPricePerTokenPriority:     litellmPricing.InputCostPerTokenPriority,
+				OutputPricePerToken:            litellmPricing.OutputCostPerToken,
+				OutputPricePerTokenPriority:    litellmPricing.OutputCostPerTokenPriority,
+				CacheCreationPricePerToken:     litellmPricing.CacheCreationInputTokenCost,
+				CacheReadPricePerToken:         litellmPricing.CacheReadInputTokenCost,
+				CacheReadPricePerTokenPriority: litellmPricing.CacheReadInputTokenCostPriority,
+				CacheCreation5mPrice:           price5m,
+				CacheCreation1hPrice:           price1h,
+				SupportsCacheBreakdown:         enableBreakdown,
+				LongContextInputThreshold:      litellmPricing.LongContextInputTokenThreshold,
+				LongContextInputMultiplier:     litellmPricing.LongContextInputCostMultiplier,
+				LongContextOutputMultiplier:    litellmPricing.LongContextOutputCostMultiplier,
 			}), nil
 		}
 	}
@@ -295,6 +357,10 @@ func (s *BillingService) GetModelPricing(model string) (*ModelPricing, error) {

 // CalculateCost 计算使用费用
 func (s *BillingService) CalculateCost(model string, tokens UsageTokens, rateMultiplier float64) (*CostBreakdown, error) {
+	return s.CalculateCostWithServiceTier(model, tokens, rateMultiplier, "")
+}
+
+func (s *BillingService) CalculateCostWithServiceTier(model string, tokens UsageTokens, rateMultiplier float64, serviceTier string) (*CostBreakdown, error) {
 	pricing, err := s.GetModelPricing(model)
 	if err != nil {
 		return nil, err
@@ -303,6 +369,21 @@ func (s *BillingService) CalculateCost(model string, tokens UsageTokens, rateMul
 	breakdown := &CostBreakdown{}
 	inputPricePerToken := pricing.InputPricePerToken
 	outputPricePerToken := pricing.OutputPricePerToken
+	cacheReadPricePerToken := pricing.CacheReadPricePerToken
+	tierMultiplier := 1.0
+	if usePriorityServiceTierPricing(serviceTier, pricing) {
+		if pricing.InputPricePerTokenPriority > 0 {
+			inputPricePerToken = pricing.InputPricePerTokenPriority
+		}
+		if pricing.OutputPricePerTokenPriority > 0 {
+			outputPricePerToken = pricing.OutputPricePerTokenPriority
+		}
+		if pricing.CacheReadPricePerTokenPriority > 0 {
+			cacheReadPricePerToken = pricing.CacheReadPricePerTokenPriority
+		}
+	} else {
+		tierMultiplier = serviceTierCostMultiplier(serviceTier)
+	}
 	if s.shouldApplySessionLongContextPricing(tokens, pricing) {
 		inputPricePerToken *= pricing.LongContextInputMultiplier
 		outputPricePerToken *= pricing.LongContextOutputMultiplier
@@ -329,7 +410,14 @@ func (s *BillingService) CalculateCost(model string, tokens UsageTokens, rateMul
 		breakdown.CacheCreationCost = float64(tokens.CacheCreationTokens) * pricing.CacheCreationPricePerToken
 	}

-	breakdown.CacheReadCost = float64(tokens.CacheReadTokens) * pricing.CacheReadPricePerToken
+	breakdown.CacheReadCost = float64(tokens.CacheReadTokens) * cacheReadPricePerToken
+
+	if tierMultiplier != 1.0 {
+		breakdown.InputCost *= tierMultiplier
+		breakdown.OutputCost *= tierMultiplier
+		breakdown.CacheCreationCost *= tierMultiplier
+		breakdown.CacheReadCost *= tierMultiplier
+	}

 	// 计算总费用
 	breakdown.TotalCost = breakdown.InputCost + breakdown.OutputCost +
--- a/backend/internal/service/billing_service_test.go
+++ b/backend/internal/service/billing_service_test.go
@@ -522,3 +522,189 @@ func TestCalculateCost_LargeTokenCount(t *testing.T) {
 	require.False(t, math.IsNaN(cost.TotalCost))
 	require.False(t, math.IsInf(cost.TotalCost, 0))
 }
+
+func TestServiceTierCostMultiplier(t *testing.T) {
+	require.InDelta(t, 2.0, serviceTierCostMultiplier("priority"), 1e-12)
+	require.InDelta(t, 2.0, serviceTierCostMultiplier(" Priority "), 1e-12)
+	require.InDelta(t, 0.5, serviceTierCostMultiplier("flex"), 1e-12)
+	require.InDelta(t, 1.0, serviceTierCostMultiplier(""), 1e-12)
+	require.InDelta(t, 1.0, serviceTierCostMultiplier("default"), 1e-12)
+}
+
+func TestCalculateCostWithServiceTier_OpenAIPriorityUsesPriorityPricing(t *testing.T) {
+	svc := newTestBillingService()
+	tokens := UsageTokens{InputTokens: 100, OutputTokens: 50, CacheReadTokens: 20}
+
+	baseCost, err := svc.CalculateCost("gpt-5.1-codex", tokens, 1.0)
+	require.NoError(t, err)
+
+	priorityCost, err := svc.CalculateCostWithServiceTier("gpt-5.1-codex", tokens, 1.0, "priority")
+	require.NoError(t, err)
+
+	require.InDelta(t, baseCost.InputCost*2, priorityCost.InputCost, 1e-10)
+	require.InDelta(t, baseCost.OutputCost*2, priorityCost.OutputCost, 1e-10)
+	require.InDelta(t, baseCost.CacheReadCost*2, priorityCost.CacheReadCost, 1e-10)
+	require.InDelta(t, baseCost.TotalCost*2, priorityCost.TotalCost, 1e-10)
+}
+
+func TestCalculateCostWithServiceTier_FlexAppliesHalfMultiplier(t *testing.T) {
+	svc := newTestBillingService()
+	tokens := UsageTokens{InputTokens: 100, OutputTokens: 50, CacheCreationTokens: 40, CacheReadTokens: 20}
+
+	baseCost, err := svc.CalculateCost("gpt-5.4", tokens, 1.0)
+	require.NoError(t, err)
+
+	flexCost, err := svc.CalculateCostWithServiceTier("gpt-5.4", tokens, 1.0, "flex")
+	require.NoError(t, err)
+
+	require.InDelta(t, baseCost.InputCost*0.5, flexCost.InputCost, 1e-10)
+	require.InDelta(t, baseCost.OutputCost*0.5, flexCost.OutputCost, 1e-10)
+	require.InDelta(t, baseCost.CacheCreationCost*0.5, flexCost.CacheCreationCost, 1e-10)
+	require.InDelta(t, baseCost.CacheReadCost*0.5, flexCost.CacheReadCost, 1e-10)
+	require.InDelta(t, baseCost.TotalCost*0.5, flexCost.TotalCost, 1e-10)
+}
+
+func TestCalculateCostWithServiceTier_PriorityFallsBackToTierMultiplierWithoutExplicitPriorityPrice(t *testing.T) {
+	svc := newTestBillingService()
+	tokens := UsageTokens{InputTokens: 120, OutputTokens: 30, CacheCreationTokens: 12, CacheReadTokens: 8}
+
+	baseCost, err := svc.CalculateCost("claude-sonnet-4", tokens, 1.0)
+	require.NoError(t, err)
+
+	priorityCost, err := svc.CalculateCostWithServiceTier("claude-sonnet-4", tokens, 1.0, "priority")
+	require.NoError(t, err)
+
+	require.InDelta(t, baseCost.InputCost*2, priorityCost.InputCost, 1e-10)
+	require.InDelta(t, baseCost.OutputCost*2, priorityCost.OutputCost, 1e-10)
+	require.InDelta(t, baseCost.CacheCreationCost*2, priorityCost.CacheCreationCost, 1e-10)
+	require.InDelta(t, baseCost.CacheReadCost*2, priorityCost.CacheReadCost, 1e-10)
+	require.InDelta(t, baseCost.TotalCost*2, priorityCost.TotalCost, 1e-10)
+}
+
+func TestBillingServiceGetModelPricing_UsesDynamicPriorityFields(t *testing.T) {
+	pricingSvc := &PricingService{
+		pricingData: map[string]*LiteLLMModelPricing{
+			"gpt-5.4": {
+				InputCostPerToken:               2.5e-6,
+				InputCostPerTokenPriority:       5e-6,
+				OutputCostPerToken:              15e-6,
+				OutputCostPerTokenPriority:      30e-6,
+				CacheCreationInputTokenCost:     2.5e-6,
+				CacheReadInputTokenCost:         0.25e-6,
+				CacheReadInputTokenCostPriority: 0.5e-6,
+				LongContextInputTokenThreshold:  272000,
+				LongContextInputCostMultiplier:  2.0,
+				LongContextOutputCostMultiplier: 1.5,
+			},
+		},
+	}
+	svc := NewBillingService(&config.Config{}, pricingSvc)
+
+	pricing, err := svc.GetModelPricing("gpt-5.4")
+	require.NoError(t, err)
+	require.InDelta(t, 2.5e-6, pricing.InputPricePerToken, 1e-12)
+	require.InDelta(t, 5e-6, pricing.InputPricePerTokenPriority, 1e-12)
+	require.InDelta(t, 15e-6, pricing.OutputPricePerToken, 1e-12)
+	require.InDelta(t, 30e-6, pricing.OutputPricePerTokenPriority, 1e-12)
+	require.InDelta(t, 0.25e-6, pricing.CacheReadPricePerToken, 1e-12)
+	require.InDelta(t, 0.5e-6, pricing.CacheReadPricePerTokenPriority, 1e-12)
+	require.Equal(t, 272000, pricing.LongContextInputThreshold)
+	require.InDelta(t, 2.0, pricing.LongContextInputMultiplier, 1e-12)
+	require.InDelta(t, 1.5, pricing.LongContextOutputMultiplier, 1e-12)
+}
+
+func TestBillingServiceGetModelPricing_OpenAIFallbackGpt52Variants(t *testing.T) {
+	svc := newTestBillingService()
+
+	gpt52, err := svc.GetModelPricing("gpt-5.2")
+	require.NoError(t, err)
+	require.NotNil(t, gpt52)
+	require.InDelta(t, 1.75e-6, gpt52.InputPricePerToken, 1e-12)
+	require.InDelta(t, 3.5e-6, gpt52.InputPricePerTokenPriority, 1e-12)
+
+	gpt52Codex, err := svc.GetModelPricing("gpt-5.2-codex")
+	require.NoError(t, err)
+	require.NotNil(t, gpt52Codex)
+	require.InDelta(t, 1.75e-6, gpt52Codex.InputPricePerToken, 1e-12)
+	require.InDelta(t, 3.5e-6, gpt52Codex.InputPricePerTokenPriority, 1e-12)
+	require.InDelta(t, 28e-6, gpt52Codex.OutputPricePerTokenPriority, 1e-12)
+}
+
+func TestCalculateCostWithServiceTier_PriorityFallsBackToTierMultiplierWhenExplicitPriceMissing(t *testing.T) {
+	svc := NewBillingService(&config.Config{}, &PricingService{
+		pricingData: map[string]*LiteLLMModelPricing{
+			"custom-no-priority": {
+				InputCostPerToken:           1e-6,
+				OutputCostPerToken:          2e-6,
+				CacheCreationInputTokenCost: 0.5e-6,
+				CacheReadInputTokenCost:     0.25e-6,
+			},
+		},
+	})
+	tokens := UsageTokens{InputTokens: 100, OutputTokens: 50, CacheCreationTokens: 40, CacheReadTokens: 20}
+
+	baseCost, err := svc.CalculateCost("custom-no-priority", tokens, 1.0)
+	require.NoError(t, err)
+
+	priorityCost, err := svc.CalculateCostWithServiceTier("custom-no-priority", tokens, 1.0, "priority")
+	require.NoError(t, err)
+
+	require.InDelta(t, baseCost.InputCost*2, priorityCost.InputCost, 1e-10)
+	require.InDelta(t, baseCost.OutputCost*2, priorityCost.OutputCost, 1e-10)
+	require.InDelta(t, baseCost.CacheCreationCost*2, priorityCost.CacheCreationCost, 1e-10)
+	require.InDelta(t, baseCost.CacheReadCost*2, priorityCost.CacheReadCost, 1e-10)
+	require.InDelta(t, baseCost.TotalCost*2, priorityCost.TotalCost, 1e-10)
+}
+
+func TestGetModelPricing_OpenAIGpt52FallbacksExposePriorityPrices(t *testing.T) {
+	svc := newTestBillingService()
+
+	gpt52, err := svc.GetModelPricing("gpt-5.2")
+	require.NoError(t, err)
+	require.InDelta(t, 1.75e-6, gpt52.InputPricePerToken, 1e-12)
+	require.InDelta(t, 3.5e-6, gpt52.InputPricePerTokenPriority, 1e-12)
+	require.InDelta(t, 14e-6, gpt52.OutputPricePerToken, 1e-12)
+	require.InDelta(t, 28e-6, gpt52.OutputPricePerTokenPriority, 1e-12)
+
+	gpt52Codex, err := svc.GetModelPricing("gpt-5.2-codex")
+	require.NoError(t, err)
+	require.InDelta(t, 1.75e-6, gpt52Codex.InputPricePerToken, 1e-12)
+	require.InDelta(t, 3.5e-6, gpt52Codex.InputPricePerTokenPriority, 1e-12)
+	require.InDelta(t, 14e-6, gpt52Codex.OutputPricePerToken, 1e-12)
+	require.InDelta(t, 28e-6, gpt52Codex.OutputPricePerTokenPriority, 1e-12)
+}
+
+func TestGetModelPricing_MapsDynamicPriorityFieldsIntoBillingPricing(t *testing.T) {
+	svc := NewBillingService(&config.Config{}, &PricingService{
+		pricingData: map[string]*LiteLLMModelPricing{
+			"dynamic-tier-model": {
+				InputCostPerToken:                   1e-6,
+				InputCostPerTokenPriority:           2e-6,
+				OutputCostPerToken:                  3e-6,
+				OutputCostPerTokenPriority:          6e-6,
+				CacheCreationInputTokenCost:         4e-6,
+				CacheCreationInputTokenCostAbove1hr: 5e-6,
+				CacheReadInputTokenCost:             7e-7,
+				CacheReadInputTokenCostPriority:     8e-7,
+				LongContextInputTokenThreshold:      999,
+				LongContextInputCostMultiplier:      1.5,
+				LongContextOutputCostMultiplier:     1.25,
+			},
+		},
+	})
+
+	pricing, err := svc.GetModelPricing("dynamic-tier-model")
+	require.NoError(t, err)
+	require.InDelta(t, 1e-6, pricing.InputPricePerToken, 1e-12)
+	require.InDelta(t, 2e-6, pricing.InputPricePerTokenPriority, 1e-12)
+	require.InDelta(t, 3e-6, pricing.OutputPricePerToken, 1e-12)
+	require.InDelta(t, 6e-6, pricing.OutputPricePerTokenPriority, 1e-12)
+	require.InDelta(t, 4e-6, pricing.CacheCreation5mPrice, 1e-12)
+	require.InDelta(t, 5e-6, pricing.CacheCreation1hPrice, 1e-12)
+	require.True(t, pricing.SupportsCacheBreakdown)
+	require.InDelta(t, 7e-7, pricing.CacheReadPricePerToken, 1e-12)
+	require.InDelta(t, 8e-7, pricing.CacheReadPricePerTokenPriority, 1e-12)
+	require.Equal(t, 999, pricing.LongContextInputThreshold)
+	require.InDelta(t, 1.5, pricing.LongContextInputMultiplier, 1e-12)
+	require.InDelta(t, 1.25, pricing.LongContextOutputMultiplier, 1e-12)
+}
--- a/backend/internal/service/openai_gateway_record_usage_test.go
+++ b/backend/internal/service/openai_gateway_record_usage_test.go
@@ -334,3 +334,225 @@ func TestOpenAIGatewayServiceRecordUsage_ClampsActualInputTokensToZero(t *testin
 	require.NotNil(t, usageRepo.lastLog)
 	require.Equal(t, 0, usageRepo.lastLog.InputTokens)
 }
+
+func TestOpenAIGatewayServiceRecordUsage_Gpt54LongContextBillsWholeSession(t *testing.T) {
+	usageRepo := &openAIRecordUsageLogRepoStub{inserted: true}
+	userRepo := &openAIRecordUsageUserRepoStub{}
+	subRepo := &openAIRecordUsageSubRepoStub{}
+	svc := newOpenAIRecordUsageServiceForTest(usageRepo, userRepo, subRepo, nil)
+
+	err := svc.RecordUsage(context.Background(), &OpenAIRecordUsageInput{
+		Result: &OpenAIForwardResult{
+			RequestID: "resp_gpt54_long_context",
+			Usage: OpenAIUsage{
+				InputTokens:  300000,
+				OutputTokens: 2000,
+			},
+			Model:    "gpt-5.4-2026-03-05",
+			Duration: time.Second,
+		},
+		APIKey:  &APIKey{ID: 1014},
+		User:    &User{ID: 2014},
+		Account: &Account{ID: 3014},
+	})
+
+	require.NoError(t, err)
+	require.NotNil(t, usageRepo.lastLog)
+
+	expectedInput := 300000 * 2.5e-6 * 2.0
+	expectedOutput := 2000 * 15e-6 * 1.5
+	require.InDelta(t, expectedInput, usageRepo.lastLog.InputCost, 1e-10)
+	require.InDelta(t, expectedOutput, usageRepo.lastLog.OutputCost, 1e-10)
+	require.InDelta(t, expectedInput+expectedOutput, usageRepo.lastLog.TotalCost, 1e-10)
+	require.InDelta(t, (expectedInput+expectedOutput)*1.1, usageRepo.lastLog.ActualCost, 1e-10)
+	require.Equal(t, 1, userRepo.deductCalls)
+}
+
+func TestOpenAIGatewayServiceRecordUsage_ServiceTierPriorityUsesFastPricing(t *testing.T) {
+	usageRepo := &openAIRecordUsageLogRepoStub{inserted: true}
+	userRepo := &openAIRecordUsageUserRepoStub{}
+	subRepo := &openAIRecordUsageSubRepoStub{}
+	svc := newOpenAIRecordUsageServiceForTest(usageRepo, userRepo, subRepo, nil)
+	serviceTier := "priority"
+	usage := OpenAIUsage{InputTokens: 100, OutputTokens: 50}
+
+	err := svc.RecordUsage(context.Background(), &OpenAIRecordUsageInput{
+		Result: &OpenAIForwardResult{
+			RequestID:   "resp_service_tier_priority",
+			ServiceTier: &serviceTier,
+			Usage:       usage,
+			Model:       "gpt-5.4",
+			Duration:    time.Second,
+		},
+		APIKey:  &APIKey{ID: 1015},
+		User:    &User{ID: 2015},
+		Account: &Account{ID: 3015},
+	})
+
+	require.NoError(t, err)
+	require.NotNil(t, usageRepo.lastLog)
+	require.NotNil(t, usageRepo.lastLog.ServiceTier)
+	require.Equal(t, serviceTier, *usageRepo.lastLog.ServiceTier)
+
+	baseCost, calcErr := svc.billingService.CalculateCost("gpt-5.4", UsageTokens{InputTokens: 100, OutputTokens: 50}, 1.0)
+	require.NoError(t, calcErr)
+	require.InDelta(t, baseCost.TotalCost*2, usageRepo.lastLog.TotalCost, 1e-10)
+}
+
+func TestOpenAIGatewayServiceRecordUsage_ServiceTierFlexHalvesCost(t *testing.T) {
+	usageRepo := &openAIRecordUsageLogRepoStub{inserted: true}
+	userRepo := &openAIRecordUsageUserRepoStub{}
+	subRepo := &openAIRecordUsageSubRepoStub{}
+	svc := newOpenAIRecordUsageServiceForTest(usageRepo, userRepo, subRepo, nil)
+	serviceTier := "flex"
+	usage := OpenAIUsage{InputTokens: 100, OutputTokens: 50, CacheReadInputTokens: 20}
+
+	err := svc.RecordUsage(context.Background(), &OpenAIRecordUsageInput{
+		Result: &OpenAIForwardResult{
+			RequestID:   "resp_service_tier_flex",
+			ServiceTier: &serviceTier,
+			Usage:       usage,
+			Model:       "gpt-5.4",
+			Duration:    time.Second,
+		},
+		APIKey:  &APIKey{ID: 1016},
+		User:    &User{ID: 2016},
+		Account: &Account{ID: 3016},
+	})
+
+	require.NoError(t, err)
+	require.NotNil(t, usageRepo.lastLog)
+
+	baseCost, calcErr := svc.billingService.CalculateCost("gpt-5.4", UsageTokens{InputTokens: 80, OutputTokens: 50, CacheReadTokens: 20}, 1.0)
+	require.NoError(t, calcErr)
+	require.InDelta(t, baseCost.TotalCost*0.5, usageRepo.lastLog.TotalCost, 1e-10)
+}
+
+func TestNormalizeOpenAIServiceTier(t *testing.T) {
+	t.Run("fast maps to priority", func(t *testing.T) {
+		got := normalizeOpenAIServiceTier(" fast ")
+		require.NotNil(t, got)
+		require.Equal(t, "priority", *got)
+	})
+
+	t.Run("default ignored", func(t *testing.T) {
+		require.Nil(t, normalizeOpenAIServiceTier("default"))
+	})
+
+	t.Run("invalid ignored", func(t *testing.T) {
+		require.Nil(t, normalizeOpenAIServiceTier("turbo"))
+	})
+}
+
+func TestExtractOpenAIServiceTier(t *testing.T) {
+	require.Equal(t, "priority", *extractOpenAIServiceTier(map[string]any{"service_tier": "fast"}))
+	require.Equal(t, "flex", *extractOpenAIServiceTier(map[string]any{"service_tier": "flex"}))
+	require.Nil(t, extractOpenAIServiceTier(map[string]any{"service_tier": 1}))
+	require.Nil(t, extractOpenAIServiceTier(nil))
+}
+
+func TestExtractOpenAIServiceTierFromBody(t *testing.T) {
+	require.Equal(t, "priority", *extractOpenAIServiceTierFromBody([]byte(`{"service_tier":"fast"}`)))
+	require.Equal(t, "flex", *extractOpenAIServiceTierFromBody([]byte(`{"service_tier":"flex"}`)))
+	require.Nil(t, extractOpenAIServiceTierFromBody([]byte(`{"service_tier":"default"}`)))
+	require.Nil(t, extractOpenAIServiceTierFromBody(nil))
+}
+
+func TestOpenAIGatewayServiceRecordUsage_UsesBillingModelAndMetadataFields(t *testing.T) {
+	usageRepo := &openAIRecordUsageLogRepoStub{inserted: true}
+	userRepo := &openAIRecordUsageUserRepoStub{}
+	subRepo := &openAIRecordUsageSubRepoStub{}
+	svc := newOpenAIRecordUsageServiceForTest(usageRepo, userRepo, subRepo, nil)
+	serviceTier := "priority"
+	reasoning := "high"
+
+	err := svc.RecordUsage(context.Background(), &OpenAIRecordUsageInput{
+		Result: &OpenAIForwardResult{
+			RequestID:       "resp_billing_model_override",
+			BillingModel:    "gpt-5.1-codex",
+			Model:           "gpt-5.1",
+			ServiceTier:     &serviceTier,
+			ReasoningEffort: &reasoning,
+			Usage: OpenAIUsage{
+				InputTokens:  20,
+				OutputTokens: 10,
+			},
+			Duration:     2 * time.Second,
+			FirstTokenMs: func() *int { v := 120; return &v }(),
+		},
+		APIKey:    &APIKey{ID: 10, GroupID: i64p(11), Group: &Group{ID: 11, RateMultiplier: 1.2}},
+		User:      &User{ID: 20},
+		Account:   &Account{ID: 30},
+		UserAgent: "codex-cli/1.0",
+		IPAddress: "127.0.0.1",
+	})
+
+	require.NoError(t, err)
+	require.NotNil(t, usageRepo.lastLog)
+	require.Equal(t, "gpt-5.1-codex", usageRepo.lastLog.Model)
+	require.NotNil(t, usageRepo.lastLog.ServiceTier)
+	require.Equal(t, serviceTier, *usageRepo.lastLog.ServiceTier)
+	require.NotNil(t, usageRepo.lastLog.ReasoningEffort)
+	require.Equal(t, reasoning, *usageRepo.lastLog.ReasoningEffort)
+	require.NotNil(t, usageRepo.lastLog.UserAgent)
+	require.Equal(t, "codex-cli/1.0", *usageRepo.lastLog.UserAgent)
+	require.NotNil(t, usageRepo.lastLog.IPAddress)
+	require.Equal(t, "127.0.0.1", *usageRepo.lastLog.IPAddress)
+	require.NotNil(t, usageRepo.lastLog.GroupID)
+	require.Equal(t, int64(11), *usageRepo.lastLog.GroupID)
+	require.Equal(t, 1, userRepo.deductCalls)
+}
+
+func TestOpenAIGatewayServiceRecordUsage_SubscriptionBillingSetsSubscriptionFields(t *testing.T) {
+	usageRepo := &openAIRecordUsageLogRepoStub{inserted: true}
+	userRepo := &openAIRecordUsageUserRepoStub{}
+	subRepo := &openAIRecordUsageSubRepoStub{}
+	svc := newOpenAIRecordUsageServiceForTest(usageRepo, userRepo, subRepo, nil)
+	subscription := &UserSubscription{ID: 99}
+
+	err := svc.RecordUsage(context.Background(), &OpenAIRecordUsageInput{
+		Result: &OpenAIForwardResult{
+			RequestID: "resp_subscription_billing",
+			Usage:     OpenAIUsage{InputTokens: 10, OutputTokens: 5},
+			Model:     "gpt-5.1",
+			Duration:  time.Second,
+		},
+		APIKey:       &APIKey{ID: 100, GroupID: i64p(88), Group: &Group{ID: 88, SubscriptionType: SubscriptionTypeSubscription}},
+		User:         &User{ID: 200},
+		Account:      &Account{ID: 300},
+		Subscription: subscription,
+	})
+
+	require.NoError(t, err)
+	require.NotNil(t, usageRepo.lastLog)
+	require.Equal(t, BillingTypeSubscription, usageRepo.lastLog.BillingType)
+	require.NotNil(t, usageRepo.lastLog.SubscriptionID)
+	require.Equal(t, subscription.ID, *usageRepo.lastLog.SubscriptionID)
+	require.Equal(t, 1, subRepo.incrementCalls)
+	require.Equal(t, 0, userRepo.deductCalls)
+}
+
+func TestOpenAIGatewayServiceRecordUsage_SimpleModeSkipsBillingAfterPersist(t *testing.T) {
+	usageRepo := &openAIRecordUsageLogRepoStub{inserted: true}
+	userRepo := &openAIRecordUsageUserRepoStub{}
+	subRepo := &openAIRecordUsageSubRepoStub{}
+	svc := newOpenAIRecordUsageServiceForTest(usageRepo, userRepo, subRepo, nil)
+	svc.cfg.RunMode = config.RunModeSimple
+
+	err := svc.RecordUsage(context.Background(), &OpenAIRecordUsageInput{
+		Result: &OpenAIForwardResult{
+			RequestID: "resp_simple_mode",
+			Usage:     OpenAIUsage{InputTokens: 10, OutputTokens: 5},
+			Model:     "gpt-5.1",
+			Duration:  time.Second,
+		},
+		APIKey:  &APIKey{ID: 1000},
+		User:    &User{ID: 2000},
+		Account: &Account{ID: 3000},
+	})
+
+	require.NoError(t, err)
+	require.Equal(t, 1, usageRepo.calls)
+	require.Equal(t, 0, userRepo.deductCalls)
+	require.Equal(t, 0, subRepo.incrementCalls)
+}
--- a/backend/internal/service/openai_gateway_service.go
+++ b/backend/internal/service/openai_gateway_service.go
@@ -213,6 +213,9 @@ type OpenAIForwardResult struct {
 	// This is set by the Anthropic Messages conversion path where
 	// the mapped upstream model differs from the client-facing model.
 	BillingModel string
+	// ServiceTier records the OpenAI Responses API service tier, e.g. "priority" / "flex".
+	// Nil means the request did not specify a recognized tier.
+	ServiceTier *string
 	// ReasoningEffort is extracted from request body (reasoning.effort) or derived from model suffix.
 	// Stored for usage records display; nil means not provided / not applicable.
 	ReasoningEffort *string
@@ -2036,11 +2039,13 @@ func (s *OpenAIGatewayService) Forward(ctx context.Context, c *gin.Context, acco
 	}

 	reasoningEffort := extractOpenAIReasoningEffort(reqBody, originalModel)
+	serviceTier := extractOpenAIServiceTier(reqBody)

 	return &OpenAIForwardResult{
 		RequestID:       resp.Header.Get("x-request-id"),
 		Usage:           *usage,
 		Model:           originalModel,
+		ServiceTier:     serviceTier,
 		ReasoningEffort: reasoningEffort,
 		Stream:          reqStream,
 		OpenAIWSMode:    false,
@@ -2195,6 +2200,7 @@ func (s *OpenAIGatewayService) forwardOpenAIPassthrough(
 		RequestID:       resp.Header.Get("x-request-id"),
 		Usage:           *usage,
 		Model:           reqModel,
+		ServiceTier:     extractOpenAIServiceTierFromBody(body),
 		ReasoningEffort: reasoningEffort,
 		Stream:          reqStream,
 		OpenAIWSMode:    false,
@@ -3628,7 +3634,11 @@ func (s *OpenAIGatewayService) RecordUsage(ctx context.Context, input *OpenAIRec
 	if result.BillingModel != "" {
 		billingModel = result.BillingModel
 	}
-	cost, err := s.billingService.CalculateCost(billingModel, tokens, multiplier)
+	serviceTier := ""
+	if result.ServiceTier != nil {
+		serviceTier = strings.TrimSpace(*result.ServiceTier)
+	}
+	cost, err := s.billingService.CalculateCostWithServiceTier(billingModel, tokens, multiplier, serviceTier)
 	if err != nil {
 		cost = &CostBreakdown{ActualCost: 0}
 	}
@@ -3649,6 +3659,7 @@ func (s *OpenAIGatewayService) RecordUsage(ctx context.Context, input *OpenAIRec
 		AccountID:             account.ID,
 		RequestID:             result.RequestID,
 		Model:                 billingModel,
+		ServiceTier:           result.ServiceTier,
 		ReasoningEffort:       result.ReasoningEffort,
 		InputTokens:           actualInputTokens,
 		OutputTokens:          result.Usage.OutputTokens,
@@ -4047,6 +4058,40 @@ func extractOpenAIReasoningEffortFromBody(body []byte, requestedModel string) *s
 	return &value
 }

+func extractOpenAIServiceTier(reqBody map[string]any) *string {
+	if reqBody == nil {
+		return nil
+	}
+	raw, ok := reqBody["service_tier"].(string)
+	if !ok {
+		return nil
+	}
+	return normalizeOpenAIServiceTier(raw)
+}
+
+func extractOpenAIServiceTierFromBody(body []byte) *string {
+	if len(body) == 0 {
+		return nil
+	}
+	return normalizeOpenAIServiceTier(gjson.GetBytes(body, "service_tier").String())
+}
+
+func normalizeOpenAIServiceTier(raw string) *string {
+	value := strings.ToLower(strings.TrimSpace(raw))
+	if value == "" {
+		return nil
+	}
+	if value == "fast" {
+		value = "priority"
+	}
+	switch value {
+	case "priority", "flex":
+		return &value
+	default:
+		return nil
+	}
+}
+
 func getOpenAIRequestBodyMap(c *gin.Context, body []byte) (map[string]any, error) {
 	if c != nil {
 		if cached, ok := c.Get(OpenAIParsedRequestBodyKey); ok {
--- a/backend/internal/service/openai_oauth_passthrough_test.go
+++ b/backend/internal/service/openai_oauth_passthrough_test.go
@@ -671,7 +671,7 @@ func TestOpenAIGatewayService_OAuthPassthrough_StreamingSetsFirstTokenMs(t *test
 	c.Request = httptest.NewRequest(http.MethodPost, "/v1/responses", bytes.NewReader(nil))
 	c.Request.Header.Set("User-Agent", "codex_cli_rs/0.1.0")

-	originalBody := []byte(`{"model":"gpt-5.2","stream":true,"input":[{"type":"text","text":"hi"}]}`)
+	originalBody := []byte(`{"model":"gpt-5.2","stream":true,"service_tier":"fast","input":[{"type":"text","text":"hi"}]}`)

 	upstreamSSE := strings.Join([]string{
 		`data: {"type":"response.output_text.delta","delta":"h"}`,
@@ -711,6 +711,8 @@ func TestOpenAIGatewayService_OAuthPassthrough_StreamingSetsFirstTokenMs(t *test
 	require.GreaterOrEqual(t, time.Since(start), time.Duration(0))
 	require.NotNil(t, result.FirstTokenMs)
 	require.GreaterOrEqual(t, *result.FirstTokenMs, 0)
+	require.NotNil(t, result.ServiceTier)
+	require.Equal(t, "priority", *result.ServiceTier)
 }

 func TestOpenAIGatewayService_OAuthPassthrough_StreamClientDisconnectStillCollectsUsage(t *testing.T) {
@@ -777,7 +779,7 @@ func TestOpenAIGatewayService_APIKeyPassthrough_PreservesBodyAndUsesResponsesEnd
 	c.Request.Header.Set("User-Agent", "curl/8.0")
 	c.Request.Header.Set("X-Test", "keep")

-	originalBody := []byte(`{"model":"gpt-5.2","stream":false,"max_output_tokens":128,"input":[{"type":"text","text":"hi"}]}`)
+	originalBody := []byte(`{"model":"gpt-5.2","stream":false,"service_tier":"flex","max_output_tokens":128,"input":[{"type":"text","text":"hi"}]}`)
 	resp := &http.Response{
 		StatusCode: http.StatusOK,
 		Header:     http.Header{"Content-Type": []string{"application/json"}, "x-request-id": []string{"rid"}},
@@ -803,8 +805,11 @@ func TestOpenAIGatewayService_APIKeyPassthrough_PreservesBodyAndUsesResponsesEnd
 		RateMultiplier: f64p(1),
 	}

-	_, err := svc.Forward(context.Background(), c, account, originalBody)
+	result, err := svc.Forward(context.Background(), c, account, originalBody)
 	require.NoError(t, err)
+	require.NotNil(t, result)
+	require.NotNil(t, result.ServiceTier)
+	require.Equal(t, "flex", *result.ServiceTier)
 	require.NotNil(t, upstream.lastReq)
 	require.Equal(t, originalBody, upstream.lastBody)
 	require.Equal(t, "https://api.openai.com/v1/responses", upstream.lastReq.URL.String())
--- a/backend/internal/service/openai_ws_forwarder.go
+++ b/backend/internal/service/openai_ws_forwarder.go
@@ -2302,6 +2302,7 @@ func (s *OpenAIGatewayService) forwardOpenAIWSV2(
 		RequestID:       responseID,
 		Usage:           *usage,
 		Model:           originalModel,
+		ServiceTier:     extractOpenAIServiceTier(reqBody),
 		ReasoningEffort: extractOpenAIReasoningEffort(reqBody, originalModel),
 		Stream:          reqStream,
 		OpenAIWSMode:    true,
@@ -2913,6 +2914,7 @@ func (s *OpenAIGatewayService) ProxyResponsesWebSocketFromClient(
 					RequestID:       responseID,
 					Usage:           usage,
 					Model:           originalModel,
+					ServiceTier:     extractOpenAIServiceTierFromBody(payload),
 					ReasoningEffort: extractOpenAIReasoningEffortFromBody(payload, originalModel),
 					Stream:          reqStream,
 					OpenAIWSMode:    true,
--- a/backend/internal/service/openai_ws_forwarder_ingress_session_test.go
+++ b/backend/internal/service/openai_ws_forwarder_ingress_session_test.go
@@ -399,7 +399,7 @@ func TestOpenAIGatewayService_ProxyResponsesWebSocketFromClient_PassthroughModeR
 	}()

 	writeCtx, cancelWrite := context.WithTimeout(context.Background(), 3*time.Second)
-	err = clientConn.Write(writeCtx, coderws.MessageText, []byte(`{"type":"response.create","model":"gpt-5.1","stream":false}`))
+	err = clientConn.Write(writeCtx, coderws.MessageText, []byte(`{"type":"response.create","model":"gpt-5.1","stream":false,"service_tier":"fast"}`))
 	cancelWrite()
 	require.NoError(t, err)

@@ -424,6 +424,8 @@ func TestOpenAIGatewayService_ProxyResponsesWebSocketFromClient_PassthroughModeR
 		require.True(t, result.OpenAIWSMode)
 		require.Equal(t, 2, result.Usage.InputTokens)
 		require.Equal(t, 3, result.Usage.OutputTokens)
+		require.NotNil(t, result.ServiceTier)
+		require.Equal(t, "priority", *result.ServiceTier)
 	case <-time.After(2 * time.Second):
 		t.Fatal("未收到 passthrough turn 结果回调")
 	}
@@ -2593,7 +2595,7 @@ func TestOpenAIGatewayService_ProxyResponsesWebSocketFromClient_ClientDisconnect
 	require.NoError(t, err)

 	writeCtx, cancelWrite := context.WithTimeout(context.Background(), 3*time.Second)
-	err = clientConn.Write(writeCtx, coderws.MessageText, []byte(`{"type":"response.create","model":"custom-original-model","stream":false}`))
+	err = clientConn.Write(writeCtx, coderws.MessageText, []byte(`{"type":"response.create","model":"custom-original-model","stream":false,"service_tier":"flex"}`))
 	cancelWrite()
 	require.NoError(t, err)
 	// 立即关闭客户端，模拟客户端在 relay 期间断连。
@@ -2611,6 +2613,8 @@ func TestOpenAIGatewayService_ProxyResponsesWebSocketFromClient_ClientDisconnect
 		require.Equal(t, "resp_ingress_disconnect", result.RequestID)
 		require.Equal(t, 2, result.Usage.InputTokens)
 		require.Equal(t, 1, result.Usage.OutputTokens)
+		require.NotNil(t, result.ServiceTier)
+		require.Equal(t, "flex", *result.ServiceTier)
 	case <-time.After(2 * time.Second):
 		t.Fatal("未收到断连后的 turn 结果回调")
 	}
--- a/backend/internal/service/openai_ws_v2_passthrough_adapter.go
+++ b/backend/internal/service/openai_ws_v2_passthrough_adapter.go
@@ -77,6 +77,7 @@ func (s *OpenAIGatewayService) proxyResponsesWebSocketV2Passthrough(
 		return errors.New("token is empty")
 	}
 	requestModel := strings.TrimSpace(gjson.GetBytes(firstClientMessage, "model").String())
+	requestServiceTier := extractOpenAIServiceTierFromBody(firstClientMessage)
 	requestPreviousResponseID := strings.TrimSpace(gjson.GetBytes(firstClientMessage, "previous_response_id").String())
 	logOpenAIWSV2Passthrough(
 		"relay_start account_id=%d model=%s previous_response_id=%s first_message_type=%s first_message_bytes=%d",
@@ -178,6 +179,7 @@ func (s *OpenAIGatewayService) proxyResponsesWebSocketV2Passthrough(
 						CacheReadInputTokens:     turn.Usage.CacheReadInputTokens,
 					},
 					Model:           turn.RequestModel,
+					ServiceTier:     requestServiceTier,
 					Stream:          true,
 					OpenAIWSMode:    true,
 					ResponseHeaders: cloneHeader(handshakeHeaders),
@@ -225,6 +227,7 @@ func (s *OpenAIGatewayService) proxyResponsesWebSocketV2Passthrough(
 			CacheReadInputTokens:     relayResult.Usage.CacheReadInputTokens,
 		},
 		Model:           relayResult.RequestModel,
+		ServiceTier:     requestServiceTier,
 		Stream:          true,
 		OpenAIWSMode:    true,
 		ResponseHeaders: cloneHeader(handshakeHeaders),
--- a/backend/internal/service/pricing_service.go
+++ b/backend/internal/service/pricing_service.go
@@ -40,13 +40,17 @@ var (
 // 只保留我们需要的字段，使用指针来处理可能缺失的值
 type LiteLLMModelPricing struct {
 	InputCostPerToken                   float64 `json:"input_cost_per_token"`
+	InputCostPerTokenPriority           float64 `json:"input_cost_per_token_priority"`
 	OutputCostPerToken                  float64 `json:"output_cost_per_token"`
+	OutputCostPerTokenPriority          float64 `json:"output_cost_per_token_priority"`
 	CacheCreationInputTokenCost         float64 `json:"cache_creation_input_token_cost"`
 	CacheCreationInputTokenCostAbove1hr float64 `json:"cache_creation_input_token_cost_above_1hr"`
 	CacheReadInputTokenCost             float64 `json:"cache_read_input_token_cost"`
+	CacheReadInputTokenCostPriority     float64 `json:"cache_read_input_token_cost_priority"`
 	LongContextInputTokenThreshold      int     `json:"long_context_input_token_threshold,omitempty"`
 	LongContextInputCostMultiplier      float64 `json:"long_context_input_cost_multiplier,omitempty"`
 	LongContextOutputCostMultiplier     float64 `json:"long_context_output_cost_multiplier,omitempty"`
+	SupportsServiceTier                 bool    `json:"supports_service_tier"`
 	LiteLLMProvider                     string  `json:"litellm_provider"`
 	Mode                                string  `json:"mode"`
 	SupportsPromptCaching               bool    `json:"supports_prompt_caching"`
@@ -62,10 +66,14 @@ type PricingRemoteClient interface {
 // LiteLLMRawEntry 用于解析原始JSON数据
 type LiteLLMRawEntry struct {
 	InputCostPerToken                   *float64 `json:"input_cost_per_token"`
+	InputCostPerTokenPriority           *float64 `json:"input_cost_per_token_priority"`
 	OutputCostPerToken                  *float64 `json:"output_cost_per_token"`
+	OutputCostPerTokenPriority          *float64 `json:"output_cost_per_token_priority"`
 	CacheCreationInputTokenCost         *float64 `json:"cache_creation_input_token_cost"`
 	CacheCreationInputTokenCostAbove1hr *float64 `json:"cache_creation_input_token_cost_above_1hr"`
 	CacheReadInputTokenCost             *float64 `json:"cache_read_input_token_cost"`
+	CacheReadInputTokenCostPriority     *float64 `json:"cache_read_input_token_cost_priority"`
+	SupportsServiceTier                 bool     `json:"supports_service_tier"`
 	LiteLLMProvider                     string   `json:"litellm_provider"`
 	Mode                                string   `json:"mode"`
 	SupportsPromptCaching               bool     `json:"supports_prompt_caching"`
@@ -324,14 +332,21 @@ func (s *PricingService) parsePricingData(body []byte) (map[string]*LiteLLMModel
 			LiteLLMProvider:       entry.LiteLLMProvider,
 			Mode:                  entry.Mode,
 			SupportsPromptCaching: entry.SupportsPromptCaching,
+			SupportsServiceTier:   entry.SupportsServiceTier,
 		}

 		if entry.InputCostPerToken != nil {
 			pricing.InputCostPerToken = *entry.InputCostPerToken
 		}
+		if entry.InputCostPerTokenPriority != nil {
+			pricing.InputCostPerTokenPriority = *entry.InputCostPerTokenPriority
+		}
 		if entry.OutputCostPerToken != nil {
 			pricing.OutputCostPerToken = *entry.OutputCostPerToken
 		}
+		if entry.OutputCostPerTokenPriority != nil {
+			pricing.OutputCostPerTokenPriority = *entry.OutputCostPerTokenPriority
+		}
 		if entry.CacheCreationInputTokenCost != nil {
 			pricing.CacheCreationInputTokenCost = *entry.CacheCreationInputTokenCost
 		}
@@ -341,6 +356,9 @@ func (s *PricingService) parsePricingData(body []byte) (map[string]*LiteLLMModel
 		if entry.CacheReadInputTokenCost != nil {
 			pricing.CacheReadInputTokenCost = *entry.CacheReadInputTokenCost
 		}
+		if entry.CacheReadInputTokenCostPriority != nil {
+			pricing.CacheReadInputTokenCostPriority = *entry.CacheReadInputTokenCostPriority
+		}
 		if entry.OutputCostPerImage != nil {
 			pricing.OutputCostPerImage = *entry.OutputCostPerImage
 		}
--- a/backend/internal/service/pricing_service_test.go
+++ b/backend/internal/service/pricing_service_test.go
@@ -1,11 +1,40 @@
 package service

 import (
+	"encoding/json"
 	"testing"

 	"github.com/stretchr/testify/require"
 )

+func TestParsePricingData_ParsesPriorityAndServiceTierFields(t *testing.T) {
+	svc := &PricingService{}
+	body := []byte(`{
+		"gpt-5.4": {
+			"input_cost_per_token": 0.0000025,
+			"input_cost_per_token_priority": 0.000005,
+			"output_cost_per_token": 0.000015,
+			"output_cost_per_token_priority": 0.00003,
+			"cache_creation_input_token_cost": 0.0000025,
+			"cache_read_input_token_cost": 0.00000025,
+			"cache_read_input_token_cost_priority": 0.0000005,
+			"supports_service_tier": true,
+			"supports_prompt_caching": true,
+			"litellm_provider": "openai",
+			"mode": "chat"
+		}
+	}`)
+
+	data, err := svc.parsePricingData(body)
+	require.NoError(t, err)
+	pricing := data["gpt-5.4"]
+	require.NotNil(t, pricing)
+	require.InDelta(t, 5e-6, pricing.InputCostPerTokenPriority, 1e-12)
+	require.InDelta(t, 3e-5, pricing.OutputCostPerTokenPriority, 1e-12)
+	require.InDelta(t, 5e-7, pricing.CacheReadInputTokenCostPriority, 1e-12)
+	require.True(t, pricing.SupportsServiceTier)
+}
+
 func TestGetModelPricing_Gpt53CodexSparkUsesGpt51CodexPricing(t *testing.T) {
 	sparkPricing := &LiteLLMModelPricing{InputCostPerToken: 1}
 	gpt53Pricing := &LiteLLMModelPricing{InputCostPerToken: 9}
@@ -68,3 +97,64 @@ func TestGetModelPricing_Gpt54UsesStaticFallbackWhenRemoteMissing(t *testing.T)
 	require.InDelta(t, 2.0, got.LongContextInputCostMultiplier, 1e-12)
 	require.InDelta(t, 1.5, got.LongContextOutputCostMultiplier, 1e-12)
 }
+
+func TestParsePricingData_PreservesPriorityAndServiceTierFields(t *testing.T) {
+	raw := map[string]any{
+		"gpt-5.4": map[string]any{
+			"input_cost_per_token":                 2.5e-6,
+			"input_cost_per_token_priority":        5e-6,
+			"output_cost_per_token":                15e-6,
+			"output_cost_per_token_priority":       30e-6,
+			"cache_read_input_token_cost":          0.25e-6,
+			"cache_read_input_token_cost_priority": 0.5e-6,
+			"supports_service_tier":                true,
+			"supports_prompt_caching":              true,
+			"litellm_provider":                     "openai",
+			"mode":                                 "chat",
+		},
+	}
+	body, err := json.Marshal(raw)
+	require.NoError(t, err)
+
+	svc := &PricingService{}
+	pricingMap, err := svc.parsePricingData(body)
+	require.NoError(t, err)
+
+	pricing := pricingMap["gpt-5.4"]
+	require.NotNil(t, pricing)
+	require.InDelta(t, 2.5e-6, pricing.InputCostPerToken, 1e-12)
+	require.InDelta(t, 5e-6, pricing.InputCostPerTokenPriority, 1e-12)
+	require.InDelta(t, 15e-6, pricing.OutputCostPerToken, 1e-12)
+	require.InDelta(t, 30e-6, pricing.OutputCostPerTokenPriority, 1e-12)
+	require.InDelta(t, 0.25e-6, pricing.CacheReadInputTokenCost, 1e-12)
+	require.InDelta(t, 0.5e-6, pricing.CacheReadInputTokenCostPriority, 1e-12)
+	require.True(t, pricing.SupportsServiceTier)
+}
+
+func TestParsePricingData_PreservesServiceTierPriorityFields(t *testing.T) {
+	svc := &PricingService{}
+	pricingData, err := svc.parsePricingData([]byte(`{
+		"gpt-5.4": {
+			"input_cost_per_token": 0.0000025,
+			"input_cost_per_token_priority": 0.000005,
+			"output_cost_per_token": 0.000015,
+			"output_cost_per_token_priority": 0.00003,
+			"cache_read_input_token_cost": 0.00000025,
+			"cache_read_input_token_cost_priority": 0.0000005,
+			"supports_service_tier": true,
+			"litellm_provider": "openai",
+			"mode": "chat"
+		}
+	}`))
+	require.NoError(t, err)
+
+	pricing := pricingData["gpt-5.4"]
+	require.NotNil(t, pricing)
+	require.InDelta(t, 0.0000025, pricing.InputCostPerToken, 1e-12)
+	require.InDelta(t, 0.000005, pricing.InputCostPerTokenPriority, 1e-12)
+	require.InDelta(t, 0.000015, pricing.OutputCostPerToken, 1e-12)
+	require.InDelta(t, 0.00003, pricing.OutputCostPerTokenPriority, 1e-12)
+	require.InDelta(t, 0.00000025, pricing.CacheReadInputTokenCost, 1e-12)
+	require.InDelta(t, 0.0000005, pricing.CacheReadInputTokenCostPriority, 1e-12)
+	require.True(t, pricing.SupportsServiceTier)
+}
--- a/backend/internal/service/usage_log.go
+++ b/backend/internal/service/usage_log.go
@@ -98,6 +98,8 @@ type UsageLog struct {
 	AccountID int64
 	RequestID string
 	Model     string
+	// ServiceTier records the OpenAI service tier used for billing, e.g. "priority" / "flex".
+	ServiceTier *string
 	// ReasoningEffort is the request's reasoning effort level (OpenAI Responses API),
 	// e.g. "low" / "medium" / "high" / "xhigh". Nil means not provided / not applicable.
 	ReasoningEffort *string
--- a/backend/migrations/070_add_usage_log_service_tier.sql
+++ b/backend/migrations/070_add_usage_log_service_tier.sql
@@ -0,0 +1,5 @@
+ALTER TABLE usage_logs
+    ADD COLUMN IF NOT EXISTS service_tier VARCHAR(16);
+
+CREATE INDEX IF NOT EXISTS idx_usage_logs_service_tier_created_at
+    ON usage_logs (service_tier, created_at);