Merge pull request #1097 from Ethan0x0000/pr/upstream-model-tracking

feat(usage): 新增 upstream_model 追踪，支持按模型来源统计与展示

backend/internal/handler/admin/dashboard_handler.go

@@ -273,6 +273,7 @@ func (h *DashboardHandler) GetModelStats(c *gin.Context) {
 
 	// Parse optional filter params
 	var userID, apiKeyID, accountID, groupID int64
+	modelSource := usagestats.ModelSourceRequested
 	var requestType *int16
 	var stream *bool
 	var billingType *int8
@@ -297,6 +298,13 @@ func (h *DashboardHandler) GetModelStats(c *gin.Context) {
 			groupID = id
 		}
 	}
+	if rawModelSource := strings.TrimSpace(c.Query("model_source")); rawModelSource != "" {
+		if !usagestats.IsValidModelSource(rawModelSource) {
+			response.BadRequest(c, "Invalid model_source, use requested/upstream/mapping")
+			return
+		}
+		modelSource = rawModelSource
+	}
 	if requestTypeStr := strings.TrimSpace(c.Query("request_type")); requestTypeStr != "" {
 		parsed, err := service.ParseUsageRequestType(requestTypeStr)
 		if err != nil {
@@ -323,7 +331,7 @@ func (h *DashboardHandler) GetModelStats(c *gin.Context) {
 		}
 	}
 
-	stats, hit, err := h.getModelStatsCached(c.Request.Context(), startTime, endTime, userID, apiKeyID, accountID, groupID, requestType, stream, billingType)
+	stats, hit, err := h.getModelStatsCached(c.Request.Context(), startTime, endTime, userID, apiKeyID, accountID, groupID, modelSource, requestType, stream, billingType)
 	if err != nil {
 		response.Error(c, 500, "Failed to get model statistics")
 		return
@@ -619,6 +627,12 @@ func (h *DashboardHandler) GetUserBreakdown(c *gin.Context) {
 		}
 	}
 	dim.Model = c.Query("model")
+	rawModelSource := strings.TrimSpace(c.DefaultQuery("model_source", usagestats.ModelSourceRequested))
+	if !usagestats.IsValidModelSource(rawModelSource) {
+		response.BadRequest(c, "Invalid model_source, use requested/upstream/mapping")
+		return
+	}
+	dim.ModelType = rawModelSource
 	dim.Endpoint = c.Query("endpoint")
 	dim.EndpointType = c.DefaultQuery("endpoint_type", "inbound")
 

backend/internal/handler/admin/dashboard_handler_request_type_test.go

@@ -149,6 +149,28 @@ func TestDashboardModelStatsInvalidStream(t *testing.T) {
 	require.Equal(t, http.StatusBadRequest, rec.Code)
 }
 
+func TestDashboardModelStatsInvalidModelSource(t *testing.T) {
+	repo := &dashboardUsageRepoCapture{}
+	router := newDashboardRequestTypeTestRouter(repo)
+
+	req := httptest.NewRequest(http.MethodGet, "/admin/dashboard/models?model_source=invalid", nil)
+	rec := httptest.NewRecorder()
+	router.ServeHTTP(rec, req)
+
+	require.Equal(t, http.StatusBadRequest, rec.Code)
+}
+
+func TestDashboardModelStatsValidModelSource(t *testing.T) {
+	repo := &dashboardUsageRepoCapture{}
+	router := newDashboardRequestTypeTestRouter(repo)
+
+	req := httptest.NewRequest(http.MethodGet, "/admin/dashboard/models?model_source=upstream", nil)
+	rec := httptest.NewRecorder()
+	router.ServeHTTP(rec, req)
+
+	require.Equal(t, http.StatusOK, rec.Code)
+}
+
 func TestDashboardUsersRankingLimitAndCache(t *testing.T) {
 	dashboardUsersRankingCache = newSnapshotCache(5 * time.Minute)
 	repo := &dashboardUsageRepoCapture{

backend/internal/handler/admin/dashboard_handler_user_breakdown_test.go

@@ -73,9 +73,35 @@ func TestGetUserBreakdown_ModelFilter(t *testing.T) {
 
 	require.Equal(t, http.StatusOK, w.Code)
 	require.Equal(t, "claude-opus-4-6", repo.capturedDim.Model)
+	require.Equal(t, usagestats.ModelSourceRequested, repo.capturedDim.ModelType)
 	require.Equal(t, int64(0), repo.capturedDim.GroupID)
 }
 
+func TestGetUserBreakdown_ModelSourceFilter(t *testing.T) {
+	repo := &userBreakdownRepoCapture{}
+	router := newUserBreakdownRouter(repo)
+
+	req := httptest.NewRequest(http.MethodGet,
+		"/admin/dashboard/user-breakdown?start_date=2026-03-01&end_date=2026-03-16&model=claude-opus-4-6&model_source=upstream", nil)
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	require.Equal(t, http.StatusOK, w.Code)
+	require.Equal(t, usagestats.ModelSourceUpstream, repo.capturedDim.ModelType)
+}
+
+func TestGetUserBreakdown_InvalidModelSource(t *testing.T) {
+	repo := &userBreakdownRepoCapture{}
+	router := newUserBreakdownRouter(repo)
+
+	req := httptest.NewRequest(http.MethodGet,
+		"/admin/dashboard/user-breakdown?start_date=2026-03-01&end_date=2026-03-16&model_source=foobar", nil)
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	require.Equal(t, http.StatusBadRequest, w.Code)
+}
+
 func TestGetUserBreakdown_EndpointFilter(t *testing.T) {
 	repo := &userBreakdownRepoCapture{}
 	router := newUserBreakdownRouter(repo)

backend/internal/handler/admin/dashboard_query_cache.go

@@ -38,6 +38,7 @@ type dashboardModelGroupCacheKey struct {
 	APIKeyID    int64  `json:"api_key_id"`
 	AccountID   int64  `json:"account_id"`
 	GroupID     int64  `json:"group_id"`
+	ModelSource string `json:"model_source,omitempty"`
 	RequestType *int16 `json:"request_type"`
 	Stream      *bool  `json:"stream"`
 	BillingType *int8  `json:"billing_type"`
@@ -111,6 +112,7 @@ func (h *DashboardHandler) getModelStatsCached(
 	ctx context.Context,
 	startTime, endTime time.Time,
 	userID, apiKeyID, accountID, groupID int64,
+	modelSource string,
 	requestType *int16,
 	stream *bool,
 	billingType *int8,
@@ -122,12 +124,13 @@ func (h *DashboardHandler) getModelStatsCached(
 		APIKeyID:    apiKeyID,
 		AccountID:   accountID,
 		GroupID:     groupID,
+		ModelSource: usagestats.NormalizeModelSource(modelSource),
 		RequestType: requestType,
 		Stream:      stream,
 		BillingType: billingType,
 	})
 	entry, hit, err := dashboardModelStatsCache.GetOrLoad(key, func() (any, error) {
-		return h.dashboardService.GetModelStatsWithFilters(ctx, startTime, endTime, userID, apiKeyID, accountID, groupID, requestType, stream, billingType)
+		return h.dashboardService.GetModelStatsWithFiltersBySource(ctx, startTime, endTime, userID, apiKeyID, accountID, groupID, requestType, stream, billingType, modelSource)
 	})
 	if err != nil {
 		return nil, hit, err

backend/internal/handler/admin/dashboard_snapshot_v2_handler.go

@@ -200,6 +200,7 @@ func (h *DashboardHandler) buildSnapshotV2Response(
 			filters.APIKeyID,
 			filters.AccountID,
 			filters.GroupID,
+			usagestats.ModelSourceRequested,
 			filters.RequestType,
 			filters.Stream,
 			filters.BillingType,

backend/internal/handler/dto/mappers.go

@@ -523,6 +523,7 @@ func usageLogFromServiceUser(l *service.UsageLog) UsageLog {
 		AccountID:             l.AccountID,
 		RequestID:             l.RequestID,
 		Model:                 l.Model,
+		UpstreamModel:         l.UpstreamModel,
 		ServiceTier:           l.ServiceTier,
 		ReasoningEffort:       l.ReasoningEffort,
 		InboundEndpoint:       l.InboundEndpoint,

backend/internal/handler/dto/types.go

@@ -334,6 +334,9 @@ type UsageLog struct {
 	AccountID int64  `json:"account_id"`
 	RequestID string `json:"request_id"`
 	Model     string `json:"model"`
+	// UpstreamModel is the actual model sent to the upstream provider after mapping.
+	// Omitted when no mapping was applied (requested model was used as-is).
+	UpstreamModel *string `json:"upstream_model,omitempty"`
 	// 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.

backend/internal/pkg/usagestats/usage_log_types.go

@@ -3,6 +3,28 @@ package usagestats
 
 import "time"
 
+const (
+	ModelSourceRequested = "requested"
+	ModelSourceUpstream  = "upstream"
+	ModelSourceMapping   = "mapping"
+)
+
+func IsValidModelSource(source string) bool {
+	switch source {
+	case ModelSourceRequested, ModelSourceUpstream, ModelSourceMapping:
+		return true
+	default:
+		return false
+	}
+}
+
+func NormalizeModelSource(source string) string {
+	if IsValidModelSource(source) {
+		return source
+	}
+	return ModelSourceRequested
+}
+
 // DashboardStats 仪表盘统计
 type DashboardStats struct {
 	// 用户统计
@@ -150,6 +172,7 @@ type UserBreakdownItem struct {
 type UserBreakdownDimension struct {
 	GroupID      int64  // filter by group_id (>0 to enable)
 	Model        string // filter by model name (non-empty to enable)
+	ModelType    string // "requested", "upstream", or "mapping"
 	Endpoint     string // filter by endpoint value (non-empty to enable)
 	EndpointType string // "inbound", "upstream", or "path"
 }

backend/internal/pkg/usagestats/usage_log_types_test.go

@@ -0,0 +1,47 @@
+package usagestats
+
+import "testing"
+
+func TestIsValidModelSource(t *testing.T) {
+	tests := []struct {
+		name   string
+		source string
+		want   bool
+	}{
+		{name: "requested", source: ModelSourceRequested, want: true},
+		{name: "upstream", source: ModelSourceUpstream, want: true},
+		{name: "mapping", source: ModelSourceMapping, want: true},
+		{name: "invalid", source: "foobar", want: false},
+		{name: "empty", source: "", want: false},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := IsValidModelSource(tc.source); got != tc.want {
+				t.Fatalf("IsValidModelSource(%q)=%v want %v", tc.source, got, tc.want)
+			}
+		})
+	}
+}
+
+func TestNormalizeModelSource(t *testing.T) {
+	tests := []struct {
+		name   string
+		source string
+		want   string
+	}{
+		{name: "requested", source: ModelSourceRequested, want: ModelSourceRequested},
+		{name: "upstream", source: ModelSourceUpstream, want: ModelSourceUpstream},
+		{name: "mapping", source: ModelSourceMapping, want: ModelSourceMapping},
+		{name: "invalid falls back", source: "foobar", want: ModelSourceRequested},
+		{name: "empty falls back", source: "", want: ModelSourceRequested},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := NormalizeModelSource(tc.source); got != tc.want {
+				t.Fatalf("NormalizeModelSource(%q)=%q want %q", tc.source, got, tc.want)
+			}
+		})
+	}
+}

backend/internal/repository/usage_log_repo.go

@@ -28,7 +28,7 @@ import (
 	gocache "github.com/patrickmn/go-cache"
 )
 
-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, inbound_endpoint, upstream_endpoint, cache_ttl_overridden, created_at"
+const usageLogSelectColumns = "id, user_id, api_key_id, account_id, request_id, model, upstream_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, inbound_endpoint, upstream_endpoint, cache_ttl_overridden, created_at"
 
 var usageLogInsertArgTypes = [...]string{
 	"bigint",
@@ -36,6 +36,7 @@ var usageLogInsertArgTypes = [...]string{
 	"bigint",
 	"text",
 	"text",
+	"text",
 	"bigint",
 	"bigint",
 	"integer",
@@ -277,6 +278,7 @@ func (r *usageLogRepository) createSingle(ctx context.Context, sqlq sqlExecutor,
 			account_id,
 			request_id,
 			model,
+			upstream_model,
 			group_id,
 			subscription_id,
 			input_tokens,
@@ -311,12 +313,12 @@ func (r *usageLogRepository) createSingle(ctx context.Context, sqlq sqlExecutor,
 			cache_ttl_overridden,
 			created_at
 		) VALUES (
-			$1, $2, $3, $4, $5,
-			$6, $7,
-			$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, $36, $37, $38
+			$1, $2, $3, $4, $5, $6,
+			$7, $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, $36, $37, $38, $39
 		)
 		ON CONFLICT (request_id, api_key_id) DO NOTHING
 		RETURNING id, created_at
@@ -707,6 +709,7 @@ func buildUsageLogBatchInsertQuery(keys []string, preparedByKey map[string]usage
 			account_id,
 			request_id,
 			model,
+			upstream_model,
 			group_id,
 			subscription_id,
 			input_tokens,
@@ -742,7 +745,7 @@ func buildUsageLogBatchInsertQuery(keys []string, preparedByKey map[string]usage
 			created_at
 		) AS (VALUES `)
 
-	args := make([]any, 0, len(keys)*38)
+	args := make([]any, 0, len(keys)*39)
 	argPos := 1
 	for idx, key := range keys {
 		if idx > 0 {
@@ -776,6 +779,7 @@ func buildUsageLogBatchInsertQuery(keys []string, preparedByKey map[string]usage
 				account_id,
 				request_id,
 				model,
+				upstream_model,
 				group_id,
 				subscription_id,
 				input_tokens,
@@ -816,6 +820,7 @@ func buildUsageLogBatchInsertQuery(keys []string, preparedByKey map[string]usage
 				account_id,
 				request_id,
 				model,
+				upstream_model,
 				group_id,
 				subscription_id,
 				input_tokens,
@@ -896,6 +901,7 @@ func buildUsageLogBestEffortInsertQuery(preparedList []usageLogInsertPrepared) (
 			account_id,
 			request_id,
 			model,
+			upstream_model,
 			group_id,
 			subscription_id,
 			input_tokens,
@@ -931,7 +937,7 @@ func buildUsageLogBestEffortInsertQuery(preparedList []usageLogInsertPrepared) (
 			created_at
 		) AS (VALUES `)
 
-	args := make([]any, 0, len(preparedList)*38)
+	args := make([]any, 0, len(preparedList)*39)
 	argPos := 1
 	for idx, prepared := range preparedList {
 		if idx > 0 {
@@ -962,6 +968,7 @@ func buildUsageLogBestEffortInsertQuery(preparedList []usageLogInsertPrepared) (
 			account_id,
 			request_id,
 			model,
+			upstream_model,
 			group_id,
 			subscription_id,
 			input_tokens,
@@ -1002,6 +1009,7 @@ func buildUsageLogBestEffortInsertQuery(preparedList []usageLogInsertPrepared) (
 			account_id,
 			request_id,
 			model,
+			upstream_model,
 			group_id,
 			subscription_id,
 			input_tokens,
@@ -1050,6 +1058,7 @@ func execUsageLogInsertNoResult(ctx context.Context, sqlq sqlExecutor, prepared
 			account_id,
 			request_id,
 			model,
+			upstream_model,
 			group_id,
 			subscription_id,
 			input_tokens,
@@ -1084,12 +1093,12 @@ func execUsageLogInsertNoResult(ctx context.Context, sqlq sqlExecutor, prepared
 			cache_ttl_overridden,
 			created_at
 		) VALUES (
-			$1, $2, $3, $4, $5,
-			$6, $7,
-			$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, $36, $37, $38
+			$1, $2, $3, $4, $5, $6,
+			$7, $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, $36, $37, $38, $39
 		)
 		ON CONFLICT (request_id, api_key_id) DO NOTHING
 	`, prepared.args...)
@@ -1121,6 +1130,7 @@ func prepareUsageLogInsert(log *service.UsageLog) usageLogInsertPrepared {
 	reasoningEffort := nullString(log.ReasoningEffort)
 	inboundEndpoint := nullString(log.InboundEndpoint)
 	upstreamEndpoint := nullString(log.UpstreamEndpoint)
+	upstreamModel := nullString(log.UpstreamModel)
 
 	var requestIDArg any
 	if requestID != "" {
@@ -1138,6 +1148,7 @@ func prepareUsageLogInsert(log *service.UsageLog) usageLogInsertPrepared {
 			log.AccountID,
 			requestIDArg,
 			log.Model,
+			upstreamModel,
 			groupID,
 			subscriptionID,
 			log.InputTokens,
@@ -2864,15 +2875,26 @@ func (r *usageLogRepository) getUsageTrendFromAggregates(ctx context.Context, st
 
 // GetModelStatsWithFilters returns model statistics with optional filters
 func (r *usageLogRepository) GetModelStatsWithFilters(ctx context.Context, startTime, endTime time.Time, userID, apiKeyID, accountID, groupID int64, requestType *int16, stream *bool, billingType *int8) (results []ModelStat, err error) {
+	return r.getModelStatsWithFiltersBySource(ctx, startTime, endTime, userID, apiKeyID, accountID, groupID, requestType, stream, billingType, usagestats.ModelSourceRequested)
+}
+
+// GetModelStatsWithFiltersBySource returns model statistics with optional filters and model source dimension.
+// source: requested | upstream | mapping.
+func (r *usageLogRepository) GetModelStatsWithFiltersBySource(ctx context.Context, startTime, endTime time.Time, userID, apiKeyID, accountID, groupID int64, requestType *int16, stream *bool, billingType *int8, source string) (results []ModelStat, err error) {
+	return r.getModelStatsWithFiltersBySource(ctx, startTime, endTime, userID, apiKeyID, accountID, groupID, requestType, stream, billingType, source)
+}
+
+func (r *usageLogRepository) getModelStatsWithFiltersBySource(ctx context.Context, startTime, endTime time.Time, userID, apiKeyID, accountID, groupID int64, requestType *int16, stream *bool, billingType *int8, source string) (results []ModelStat, err error) {
 	actualCostExpr := "COALESCE(SUM(actual_cost), 0) as actual_cost"
 	// 当仅按 account_id 聚合时，实际费用使用账号倍率（total_cost * account_rate_multiplier）。
 	if accountID > 0 && userID == 0 && apiKeyID == 0 {
 		actualCostExpr = "COALESCE(SUM(total_cost * COALESCE(account_rate_multiplier, 1)), 0) as actual_cost"
 	}
+	modelExpr := resolveModelDimensionExpression(source)
 
 	query := fmt.Sprintf(`
 		SELECT
-			model,
+			%s as model,
 			COUNT(*) as requests,
 			COALESCE(SUM(input_tokens), 0) as input_tokens,
 			COALESCE(SUM(output_tokens), 0) as output_tokens,
@@ -2883,7 +2905,7 @@ func (r *usageLogRepository) GetModelStatsWithFilters(ctx context.Context, start
 			%s
 		FROM usage_logs
 		WHERE created_at >= $1 AND created_at < $2
-	`, actualCostExpr)
+	`, modelExpr, actualCostExpr)
 
 	args := []any{startTime, endTime}
 	if userID > 0 {
@@ -2907,7 +2929,7 @@ func (r *usageLogRepository) GetModelStatsWithFilters(ctx context.Context, start
 		query += fmt.Sprintf(" AND billing_type = $%d", len(args)+1)
 		args = append(args, int16(*billingType))
 	}
-	query += " GROUP BY model ORDER BY total_tokens DESC"
+	query += fmt.Sprintf(" GROUP BY %s ORDER BY total_tokens DESC", modelExpr)
 
 	rows, err := r.sql.QueryContext(ctx, query, args...)
 	if err != nil {
@@ -3021,7 +3043,7 @@ func (r *usageLogRepository) GetUserBreakdownStats(ctx context.Context, startTim
 		args = append(args, dim.GroupID)
 	}
 	if dim.Model != "" {
-		query += fmt.Sprintf(" AND ul.model = $%d", len(args)+1)
+		query += fmt.Sprintf(" AND %s = $%d", resolveModelDimensionExpression(dim.ModelType), len(args)+1)
 		args = append(args, dim.Model)
 	}
 	if dim.Endpoint != "" {
@@ -3102,6 +3124,18 @@ func (r *usageLogRepository) GetAllGroupUsageSummary(ctx context.Context, todayS
 	return results, nil
 }
 
+// resolveModelDimensionExpression maps model source type to a safe SQL expression.
+func resolveModelDimensionExpression(modelType string) string {
+	switch usagestats.NormalizeModelSource(modelType) {
+	case usagestats.ModelSourceUpstream:
+		return "COALESCE(NULLIF(TRIM(upstream_model), ''), model)"
+	case usagestats.ModelSourceMapping:
+		return "(model || ' -> ' || COALESCE(NULLIF(TRIM(upstream_model), ''), model))"
+	default:
+		return "model"
+	}
+}
+
 // resolveEndpointColumn maps endpoint type to the corresponding DB column name.
 func resolveEndpointColumn(endpointType string) string {
 	switch endpointType {
@@ -3854,6 +3888,7 @@ func scanUsageLog(scanner interface{ Scan(...any) error }) (*service.UsageLog, e
 		accountID             int64
 		requestID             sql.NullString
 		model                 string
+		upstreamModel         sql.NullString
 		groupID               sql.NullInt64
 		subscriptionID        sql.NullInt64
 		inputTokens           int
@@ -3896,6 +3931,7 @@ func scanUsageLog(scanner interface{ Scan(...any) error }) (*service.UsageLog, e
 		&accountID,
 		&requestID,
 		&model,
+		&upstreamModel,
 		&groupID,
 		&subscriptionID,
 		&inputTokens,
@@ -4008,6 +4044,9 @@ func scanUsageLog(scanner interface{ Scan(...any) error }) (*service.UsageLog, e
 	if upstreamEndpoint.Valid {
 		log.UpstreamEndpoint = &upstreamEndpoint.String
 	}
+	if upstreamModel.Valid {
+		log.UpstreamModel = &upstreamModel.String
+	}
 
 	return log, nil
 }

backend/internal/repository/usage_log_repo_breakdown_test.go

@@ -5,6 +5,7 @@ package repository
 import (
 	"testing"
 
+	"github.com/Wei-Shaw/sub2api/internal/pkg/usagestats"
 	"github.com/stretchr/testify/require"
 )
 
@@ -16,8 +17,8 @@ func TestResolveEndpointColumn(t *testing.T) {
 		{"inbound", "ul.inbound_endpoint"},
 		{"upstream", "ul.upstream_endpoint"},
 		{"path", "ul.inbound_endpoint || ' -> ' || ul.upstream_endpoint"},
-		{"", "ul.inbound_endpoint"},           // default
-		{"unknown", "ul.inbound_endpoint"},     // fallback
+		{"", "ul.inbound_endpoint"},        // default
+		{"unknown", "ul.inbound_endpoint"}, // fallback
 	}
 
 	for _, tc := range tests {
@@ -27,3 +28,23 @@ func TestResolveEndpointColumn(t *testing.T) {
 		})
 	}
 }
+
+func TestResolveModelDimensionExpression(t *testing.T) {
+	tests := []struct {
+		modelType string
+		want      string
+	}{
+		{usagestats.ModelSourceRequested, "model"},
+		{usagestats.ModelSourceUpstream, "COALESCE(NULLIF(TRIM(upstream_model), ''), model)"},
+		{usagestats.ModelSourceMapping, "(model || ' -> ' || COALESCE(NULLIF(TRIM(upstream_model), ''), model))"},
+		{"", "model"},
+		{"invalid", "model"},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.modelType, func(t *testing.T) {
+			got := resolveModelDimensionExpression(tc.modelType)
+			require.Equal(t, tc.want, got)
+		})
+	}
+}

backend/internal/repository/usage_log_repo_request_type_test.go

@@ -44,6 +44,7 @@ func TestUsageLogRepositoryCreateSyncRequestTypeAndLegacyFields(t *testing.T) {
 			log.AccountID,
 			log.RequestID,
 			log.Model,
+			sqlmock.AnyArg(), // upstream_model
 			sqlmock.AnyArg(), // group_id
 			sqlmock.AnyArg(), // subscription_id
 			log.InputTokens,
@@ -116,6 +117,7 @@ func TestUsageLogRepositoryCreate_PersistsServiceTier(t *testing.T) {
 			log.Model,
 			sqlmock.AnyArg(),
 			sqlmock.AnyArg(),
+			sqlmock.AnyArg(),
 			log.InputTokens,
 			log.OutputTokens,
 			log.CacheCreationTokens,
@@ -353,6 +355,7 @@ func TestScanUsageLogRequestTypeAndLegacyFallback(t *testing.T) {
 			int64(30), // account_id
 			sql.NullString{Valid: true, String: "req-1"},
 			"gpt-5",           // model
+			sql.NullString{},  // upstream_model
 			sql.NullInt64{},   // group_id
 			sql.NullInt64{},   // subscription_id
 			1,                 // input_tokens
@@ -404,6 +407,7 @@ func TestScanUsageLogRequestTypeAndLegacyFallback(t *testing.T) {
 			int64(31),
 			sql.NullString{Valid: true, String: "req-2"},
 			"gpt-5",
+			sql.NullString{},
 			sql.NullInt64{},
 			sql.NullInt64{},
 			1, 2, 3, 4, 5, 6,
@@ -445,6 +449,7 @@ func TestScanUsageLogRequestTypeAndLegacyFallback(t *testing.T) {
 			int64(32),
 			sql.NullString{Valid: true, String: "req-3"},
 			"gpt-5.4",
+			sql.NullString{},
 			sql.NullInt64{},
 			sql.NullInt64{},
 			1, 2, 3, 4, 5, 6,

backend/internal/service/dashboard_service.go

@@ -140,6 +140,27 @@ func (s *DashboardService) GetModelStatsWithFilters(ctx context.Context, startTi
 	return stats, nil
 }
 
+func (s *DashboardService) GetModelStatsWithFiltersBySource(ctx context.Context, startTime, endTime time.Time, userID, apiKeyID, accountID, groupID int64, requestType *int16, stream *bool, billingType *int8, modelSource string) ([]usagestats.ModelStat, error) {
+	normalizedSource := usagestats.NormalizeModelSource(modelSource)
+	if normalizedSource == usagestats.ModelSourceRequested {
+		return s.GetModelStatsWithFilters(ctx, startTime, endTime, userID, apiKeyID, accountID, groupID, requestType, stream, billingType)
+	}
+
+	type modelStatsBySourceRepo interface {
+		GetModelStatsWithFiltersBySource(ctx context.Context, startTime, endTime time.Time, userID, apiKeyID, accountID, groupID int64, requestType *int16, stream *bool, billingType *int8, source string) ([]usagestats.ModelStat, error)
+	}
+
+	if sourceRepo, ok := s.usageRepo.(modelStatsBySourceRepo); ok {
+		stats, err := sourceRepo.GetModelStatsWithFiltersBySource(ctx, startTime, endTime, userID, apiKeyID, accountID, groupID, requestType, stream, billingType, normalizedSource)
+		if err != nil {
+			return nil, fmt.Errorf("get model stats with filters by source: %w", err)
+		}
+		return stats, nil
+	}
+
+	return s.GetModelStatsWithFilters(ctx, startTime, endTime, userID, apiKeyID, accountID, groupID, requestType, stream, billingType)
+}
+
 func (s *DashboardService) GetGroupStatsWithFilters(ctx context.Context, startTime, endTime time.Time, userID, apiKeyID, accountID, groupID int64, requestType *int16, stream *bool, billingType *int8) ([]usagestats.GroupStat, error) {
 	stats, err := s.usageRepo.GetGroupStatsWithFilters(ctx, startTime, endTime, userID, apiKeyID, accountID, groupID, requestType, stream, billingType)
 	if err != nil {

backend/internal/service/gateway_anthropic_apikey_passthrough_test.go

@@ -788,7 +788,7 @@ func TestGatewayService_AnthropicAPIKeyPassthrough_ForwardDirect_NonStreamingSuc
 		rateLimitService: &RateLimitService{},
 	}
 
-	result, err := svc.forwardAnthropicAPIKeyPassthrough(context.Background(), c, newAnthropicAPIKeyAccountForTest(), body, "claude-3-5-sonnet-latest", false, time.Now())
+	result, err := svc.forwardAnthropicAPIKeyPassthrough(context.Background(), c, newAnthropicAPIKeyAccountForTest(), body, "claude-3-5-sonnet-latest", "claude-3-5-sonnet-latest", false, time.Now())
 	require.NoError(t, err)
 	require.NotNil(t, result)
 	require.Equal(t, 12, result.Usage.InputTokens)
@@ -815,7 +815,7 @@ func TestGatewayService_AnthropicAPIKeyPassthrough_ForwardDirect_InvalidTokenTyp
 	}
 	svc := &GatewayService{}
 
-	result, err := svc.forwardAnthropicAPIKeyPassthrough(context.Background(), c, account, []byte(`{}`), "claude-3-5-sonnet-latest", false, time.Now())
+	result, err := svc.forwardAnthropicAPIKeyPassthrough(context.Background(), c, account, []byte(`{}`), "claude-3-5-sonnet-latest", "claude-3-5-sonnet-latest", false, time.Now())
 	require.Nil(t, result)
 	require.Error(t, err)
 	require.Contains(t, err.Error(), "requires apikey token")
@@ -840,7 +840,7 @@ func TestGatewayService_AnthropicAPIKeyPassthrough_ForwardDirect_UpstreamRequest
 	}
 	account := newAnthropicAPIKeyAccountForTest()
 
-	result, err := svc.forwardAnthropicAPIKeyPassthrough(context.Background(), c, account, []byte(`{"model":"x"}`), "x", false, time.Now())
+	result, err := svc.forwardAnthropicAPIKeyPassthrough(context.Background(), c, account, []byte(`{"model":"x"}`), "x", "x", false, time.Now())
 	require.Nil(t, result)
 	require.Error(t, err)
 	require.Contains(t, err.Error(), "upstream request failed")
@@ -873,7 +873,7 @@ func TestGatewayService_AnthropicAPIKeyPassthrough_ForwardDirect_EmptyResponseBo
 		httpUpstream: upstream,
 	}
 
-	result, err := svc.forwardAnthropicAPIKeyPassthrough(context.Background(), c, newAnthropicAPIKeyAccountForTest(), []byte(`{"model":"x"}`), "x", false, time.Now())
+	result, err := svc.forwardAnthropicAPIKeyPassthrough(context.Background(), c, newAnthropicAPIKeyAccountForTest(), []byte(`{"model":"x"}`), "x", "x", false, time.Now())
 	require.Nil(t, result)
 	require.Error(t, err)
 	require.Contains(t, err.Error(), "empty response")

backend/internal/service/gateway_service.go

@@ -490,6 +490,7 @@ type ForwardResult struct {
 	RequestID        string
 	Usage            ClaudeUsage
 	Model            string
+	UpstreamModel    string // Actual upstream model after mapping (empty = no mapping)
 	Stream           bool
 	Duration         time.Duration
 	FirstTokenMs     *int // 首字时间（流式请求）
@@ -3988,7 +3989,13 @@ func (s *GatewayService) Forward(ctx context.Context, c *gin.Context, account *A
 				passthroughModel = mappedModel
 			}
 		}
-		return s.forwardAnthropicAPIKeyPassthrough(ctx, c, account, passthroughBody, passthroughModel, parsed.Stream, startTime)
+		return s.forwardAnthropicAPIKeyPassthroughWithInput(ctx, c, account, anthropicPassthroughForwardInput{
+			Body:          passthroughBody,
+			RequestModel:  passthroughModel,
+			OriginalModel: parsed.Model,
+			RequestStream: parsed.Stream,
+			StartTime:     startTime,
+		})
 	}
 
 	if account != nil && account.IsBedrock() {
@@ -4512,6 +4519,7 @@ func (s *GatewayService) Forward(ctx context.Context, c *gin.Context, account *A
 		RequestID:        resp.Header.Get("x-request-id"),
 		Usage:            *usage,
 		Model:            originalModel, // 使用原始模型用于计费和日志
+		UpstreamModel:    mappedModel,
 		Stream:           reqStream,
 		Duration:         time.Since(startTime),
 		FirstTokenMs:     firstTokenMs,
@@ -4519,14 +4527,38 @@ func (s *GatewayService) Forward(ctx context.Context, c *gin.Context, account *A
 	}, nil
 }
 
+type anthropicPassthroughForwardInput struct {
+	Body          []byte
+	RequestModel  string
+	OriginalModel string
+	RequestStream bool
+	StartTime     time.Time
+}
+
 func (s *GatewayService) forwardAnthropicAPIKeyPassthrough(
 	ctx context.Context,
 	c *gin.Context,
 	account *Account,
 	body []byte,
 	reqModel string,
+	originalModel string,
 	reqStream bool,
 	startTime time.Time,
+) (*ForwardResult, error) {
+	return s.forwardAnthropicAPIKeyPassthroughWithInput(ctx, c, account, anthropicPassthroughForwardInput{
+		Body:          body,
+		RequestModel:  reqModel,
+		OriginalModel: originalModel,
+		RequestStream: reqStream,
+		StartTime:     startTime,
+	})
+}
+
+func (s *GatewayService) forwardAnthropicAPIKeyPassthroughWithInput(
+	ctx context.Context,
+	c *gin.Context,
+	account *Account,
+	input anthropicPassthroughForwardInput,
 ) (*ForwardResult, error) {
 	token, tokenType, err := s.GetAccessToken(ctx, account)
 	if err != nil {
@@ -4542,19 +4574,19 @@ func (s *GatewayService) forwardAnthropicAPIKeyPassthrough(
 	}
 
 	logger.LegacyPrintf("service.gateway", "[Anthropic 自动透传] 命中 API Key 透传分支: account=%d name=%s model=%s stream=%v",
-		account.ID, account.Name, reqModel, reqStream)
+		account.ID, account.Name, input.RequestModel, input.RequestStream)
 
 	if c != nil {
 		c.Set("anthropic_passthrough", true)
 	}
 	// 重试间复用同一请求体，避免每次 string(body) 产生额外分配。
-	setOpsUpstreamRequestBody(c, body)
+	setOpsUpstreamRequestBody(c, input.Body)
 
 	var resp *http.Response
 	retryStart := time.Now()
 	for attempt := 1; attempt <= maxRetryAttempts; attempt++ {
-		upstreamCtx, releaseUpstreamCtx := detachStreamUpstreamContext(ctx, reqStream)
-		upstreamReq, err := s.buildUpstreamRequestAnthropicAPIKeyPassthrough(upstreamCtx, c, account, body, token)
+		upstreamCtx, releaseUpstreamCtx := detachStreamUpstreamContext(ctx, input.RequestStream)
+		upstreamReq, err := s.buildUpstreamRequestAnthropicAPIKeyPassthrough(upstreamCtx, c, account, input.Body, token)
 		releaseUpstreamCtx()
 		if err != nil {
 			return nil, err
@@ -4712,8 +4744,8 @@ func (s *GatewayService) forwardAnthropicAPIKeyPassthrough(
 	var usage *ClaudeUsage
 	var firstTokenMs *int
 	var clientDisconnect bool
-	if reqStream {
-		streamResult, err := s.handleStreamingResponseAnthropicAPIKeyPassthrough(ctx, resp, c, account, startTime, reqModel)
+	if input.RequestStream {
+		streamResult, err := s.handleStreamingResponseAnthropicAPIKeyPassthrough(ctx, resp, c, account, input.StartTime, input.RequestModel)
 		if err != nil {
 			return nil, err
 		}
@@ -4733,9 +4765,10 @@ func (s *GatewayService) forwardAnthropicAPIKeyPassthrough(
 	return &ForwardResult{
 		RequestID:        resp.Header.Get("x-request-id"),
 		Usage:            *usage,
-		Model:            reqModel,
-		Stream:           reqStream,
-		Duration:         time.Since(startTime),
+		Model:            input.OriginalModel,
+		UpstreamModel:    input.RequestModel,
+		Stream:           input.RequestStream,
+		Duration:         time.Since(input.StartTime),
 		FirstTokenMs:     firstTokenMs,
 		ClientDisconnect: clientDisconnect,
 	}, nil
@@ -5240,6 +5273,7 @@ func (s *GatewayService) forwardBedrock(
 		RequestID:        resp.Header.Get("x-amzn-requestid"),
 		Usage:            *usage,
 		Model:            reqModel,
+		UpstreamModel:    mappedModel,
 		Stream:           reqStream,
 		Duration:         time.Since(startTime),
 		FirstTokenMs:     firstTokenMs,
@@ -7530,6 +7564,7 @@ func (s *GatewayService) RecordUsage(ctx context.Context, input *RecordUsageInpu
 		AccountID:             account.ID,
 		RequestID:             requestID,
 		Model:                 result.Model,
+		UpstreamModel:         optionalNonEqualStringPtr(result.UpstreamModel, result.Model),
 		ReasoningEffort:       result.ReasoningEffort,
 		InboundEndpoint:       optionalTrimmedStringPtr(input.InboundEndpoint),
 		UpstreamEndpoint:      optionalTrimmedStringPtr(input.UpstreamEndpoint),
@@ -7711,6 +7746,7 @@ func (s *GatewayService) RecordUsageWithLongContext(ctx context.Context, input *
 		AccountID:             account.ID,
 		RequestID:             requestID,
 		Model:                 result.Model,
+		UpstreamModel:         optionalNonEqualStringPtr(result.UpstreamModel, result.Model),
 		ReasoningEffort:       result.ReasoningEffort,
 		InboundEndpoint:       optionalTrimmedStringPtr(input.InboundEndpoint),
 		UpstreamEndpoint:      optionalTrimmedStringPtr(input.UpstreamEndpoint),

backend/internal/service/openai_gateway_chat_completions.go

@@ -277,12 +277,13 @@ func (s *OpenAIGatewayService) handleChatBufferedStreamingResponse(
 	c.JSON(http.StatusOK, chatResp)
 
 	return &OpenAIForwardResult{
-		RequestID:    requestID,
-		Usage:        usage,
-		Model:        originalModel,
-		BillingModel: mappedModel,
-		Stream:       false,
-		Duration:     time.Since(startTime),
+		RequestID:     requestID,
+		Usage:         usage,
+		Model:         originalModel,
+		BillingModel:  mappedModel,
+		UpstreamModel: mappedModel,
+		Stream:        false,
+		Duration:      time.Since(startTime),
 	}, nil
 }
 
@@ -324,13 +325,14 @@ func (s *OpenAIGatewayService) handleChatStreamingResponse(
 
 	resultWithUsage := func() *OpenAIForwardResult {
 		return &OpenAIForwardResult{
-			RequestID:    requestID,
-			Usage:        usage,
-			Model:        originalModel,
-			BillingModel: mappedModel,
-			Stream:       true,
-			Duration:     time.Since(startTime),
-			FirstTokenMs: firstTokenMs,
+			RequestID:     requestID,
+			Usage:         usage,
+			Model:         originalModel,
+			BillingModel:  mappedModel,
+			UpstreamModel: mappedModel,
+			Stream:        true,
+			Duration:      time.Since(startTime),
+			FirstTokenMs:  firstTokenMs,
 		}
 	}
 

backend/internal/service/openai_gateway_messages.go

@@ -299,12 +299,13 @@ func (s *OpenAIGatewayService) handleAnthropicBufferedStreamingResponse(
 	c.JSON(http.StatusOK, anthropicResp)
 
 	return &OpenAIForwardResult{
-		RequestID:    requestID,
-		Usage:        usage,
-		Model:        originalModel,
-		BillingModel: mappedModel,
-		Stream:       false,
-		Duration:     time.Since(startTime),
+		RequestID:     requestID,
+		Usage:         usage,
+		Model:         originalModel,
+		BillingModel:  mappedModel,
+		UpstreamModel: mappedModel,
+		Stream:        false,
+		Duration:      time.Since(startTime),
 	}, nil
 }
 
@@ -347,13 +348,14 @@ func (s *OpenAIGatewayService) handleAnthropicStreamingResponse(
 	// resultWithUsage builds the final result snapshot.
 	resultWithUsage := func() *OpenAIForwardResult {
 		return &OpenAIForwardResult{
-			RequestID:    requestID,
-			Usage:        usage,
-			Model:        originalModel,
-			BillingModel: mappedModel,
-			Stream:       true,
-			Duration:     time.Since(startTime),
-			FirstTokenMs: firstTokenMs,
+			RequestID:     requestID,
+			Usage:         usage,
+			Model:         originalModel,
+			BillingModel:  mappedModel,
+			UpstreamModel: mappedModel,
+			Stream:        true,
+			Duration:      time.Since(startTime),
+			FirstTokenMs:  firstTokenMs,
 		}
 	}
 

backend/internal/service/openai_gateway_record_usage_test.go

@@ -846,7 +846,7 @@ func TestExtractOpenAIServiceTierFromBody(t *testing.T) {
 	require.Nil(t, extractOpenAIServiceTierFromBody(nil))
 }
 
-func TestOpenAIGatewayServiceRecordUsage_UsesBillingModelAndMetadataFields(t *testing.T) {
+func TestOpenAIGatewayServiceRecordUsage_UsesRequestedModelAndUpstreamModelMetadataFields(t *testing.T) {
 	usageRepo := &openAIRecordUsageLogRepoStub{inserted: true}
 	userRepo := &openAIRecordUsageUserRepoStub{}
 	subRepo := &openAIRecordUsageSubRepoStub{}
@@ -859,6 +859,7 @@ func TestOpenAIGatewayServiceRecordUsage_UsesBillingModelAndMetadataFields(t *te
 			RequestID:       "resp_billing_model_override",
 			BillingModel:    "gpt-5.1-codex",
 			Model:           "gpt-5.1",
+			UpstreamModel:   "gpt-5.1-codex",
 			ServiceTier:     &serviceTier,
 			ReasoningEffort: &reasoning,
 			Usage: OpenAIUsage{
@@ -877,7 +878,9 @@ func TestOpenAIGatewayServiceRecordUsage_UsesBillingModelAndMetadataFields(t *te
 
 	require.NoError(t, err)
 	require.NotNil(t, usageRepo.lastLog)
-	require.Equal(t, "gpt-5.1-codex", usageRepo.lastLog.Model)
+	require.Equal(t, "gpt-5.1", usageRepo.lastLog.Model)
+	require.NotNil(t, usageRepo.lastLog.UpstreamModel)
+	require.Equal(t, "gpt-5.1-codex", *usageRepo.lastLog.UpstreamModel)
 	require.NotNil(t, usageRepo.lastLog.ServiceTier)
 	require.Equal(t, serviceTier, *usageRepo.lastLog.ServiceTier)
 	require.NotNil(t, usageRepo.lastLog.ReasoningEffort)

backend/internal/service/openai_gateway_service.go

@@ -216,6 +216,9 @@ 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
+	// UpstreamModel is the actual model sent to the upstream provider after mapping.
+	// Empty when no mapping was applied (requested model was used as-is).
+	UpstreamModel 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
@@ -2128,6 +2131,7 @@ func (s *OpenAIGatewayService) Forward(ctx context.Context, c *gin.Context, acco
 				firstTokenMs,
 				wsAttempts,
 			)
+			wsResult.UpstreamModel = mappedModel
 			return wsResult, nil
 		}
 		s.writeOpenAIWSFallbackErrorResponse(c, account, wsErr)
@@ -2263,6 +2267,7 @@ func (s *OpenAIGatewayService) Forward(ctx context.Context, c *gin.Context, acco
 			RequestID:       resp.Header.Get("x-request-id"),
 			Usage:           *usage,
 			Model:           originalModel,
+			UpstreamModel:   mappedModel,
 			ServiceTier:     serviceTier,
 			ReasoningEffort: reasoningEffort,
 			Stream:          reqStream,
@@ -4134,7 +4139,8 @@ func (s *OpenAIGatewayService) RecordUsage(ctx context.Context, input *OpenAIRec
 		APIKeyID:              apiKey.ID,
 		AccountID:             account.ID,
 		RequestID:             requestID,
-		Model:                 billingModel,
+		Model:                 result.Model,
+		UpstreamModel:         optionalNonEqualStringPtr(result.UpstreamModel, result.Model),
 		ServiceTier:           result.ServiceTier,
 		ReasoningEffort:       result.ReasoningEffort,
 		InboundEndpoint:       optionalTrimmedStringPtr(input.InboundEndpoint),
@@ -4700,11 +4706,3 @@ func normalizeOpenAIReasoningEffort(raw string) string {
 		return ""
 	}
 }
-
-func optionalTrimmedStringPtr(raw string) *string {
-	trimmed := strings.TrimSpace(raw)
-	if trimmed == "" {
-		return nil
-	}
-	return &trimmed
-}

backend/internal/service/usage_log.go

@@ -98,6 +98,9 @@ type UsageLog struct {
 	AccountID int64
 	RequestID string
 	Model     string
+	// UpstreamModel is the actual model sent to the upstream provider after mapping.
+	// Nil means no mapping was applied (requested model was used as-is).
+	UpstreamModel *string
 	// ServiceTier records the OpenAI service tier used for billing, e.g. "priority" / "flex".
 	ServiceTier *string
 	// ReasoningEffort is the request's reasoning effort level.

backend/internal/service/usage_log_helpers.go

@@ -0,0 +1,21 @@
+package service
+
+import "strings"
+
+func optionalTrimmedStringPtr(raw string) *string {
+	trimmed := strings.TrimSpace(raw)
+	if trimmed == "" {
+		return nil
+	}
+	return &trimmed
+}
+
+// optionalNonEqualStringPtr returns a pointer to value if it is non-empty and
+// differs from compare; otherwise nil. Used to store upstream_model only when
+// it differs from the requested model.
+func optionalNonEqualStringPtr(value, compare string) *string {
+	if value == "" || value == compare {
+		return nil
+	}
+	return &value
+}