diff --git a/api/accounting.go b/api/accounting.go
new file mode 100644
index 0000000..d721b96
--- /dev/null
+++ b/api/accounting.go
@@ -0,0 +1,335 @@
+package api
+
+import (
+	"net/http"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/gin-gonic/gin"
+
+	"account/internal/store"
+)
+
+type nodeHeartbeatRequest struct {
+	NodeID            string  `json:"nodeId"`
+	Region            string  `json:"region"`
+	LineCode          string  `json:"lineCode"`
+	PricingGroup      string  `json:"pricingGroup"`
+	StatsEnabled      bool    `json:"statsEnabled"`
+	XrayRevision      string  `json:"xrayRevision"`
+	Healthy           bool    `json:"healthy"`
+	LatencyMS         int     `json:"latencyMs"`
+	ErrorRate         float64 `json:"errorRate"`
+	ActiveConnections int     `json:"activeConnections"`
+	HealthScore       float64 `json:"healthScore"`
+	SampledAt         string  `json:"sampledAt"`
+}
+
+func parseOptionalTime(value string) (time.Time, error) {
+	trimmed := strings.TrimSpace(value)
+	if trimmed == "" {
+		return time.Time{}, nil
+	}
+	parsed, err := time.Parse(time.RFC3339, trimmed)
+	if err == nil {
+		return parsed.UTC(), nil
+	}
+	return time.Parse("2006-01-02T15:04", trimmed)
+}
+
+func (h *handler) accountUsageSummary(c *gin.Context) {
+	user, ok := h.requireAuthenticatedUser(c)
+	if !ok {
+		return
+	}
+
+	buckets, err := h.store.ListTrafficMinuteBucketsByAccount(c.Request.Context(), user.ID, time.Time{}, time.Time{})
+	if err != nil {
+		respondError(c, http.StatusInternalServerError, "usage_summary_unavailable", "failed to load usage summary")
+		return
+	}
+
+	var totalBytes, uplinkBytes, downlinkBytes int64
+	var lastBucketAt *time.Time
+	for _, bucket := range buckets {
+		totalBytes += bucket.TotalBytes
+		uplinkBytes += bucket.UplinkBytes
+		downlinkBytes += bucket.DownlinkBytes
+		timestamp := bucket.BucketStart.UTC()
+		if lastBucketAt == nil || timestamp.After(*lastBucketAt) {
+			lastBucketAt = &timestamp
+		}
+	}
+
+	currentBalance := 0.0
+	remainingQuota := int64(0)
+	suspendState := "active"
+	throttleState := "normal"
+	arrears := false
+	if quota, err := h.store.GetAccountQuotaState(c.Request.Context(), user.ID); err == nil && quota != nil {
+		currentBalance = quota.CurrentBalance
+		remainingQuota = quota.RemainingIncludedQuota
+		suspendState = quota.SuspendState
+		throttleState = quota.ThrottleState
+		arrears = quota.Arrears
+	}
+
+	syncDelaySeconds := 0
+	if lastBucketAt != nil {
+		syncDelaySeconds = int(time.Since(*lastBucketAt).Seconds())
+		if syncDelaySeconds < 0 {
+			syncDelaySeconds = 0
+		}
+	}
+
+	c.JSON(http.StatusOK, gin.H{
+		"accountUuid":            user.ID,
+		"totalBytes":             totalBytes,
+		"uplinkBytes":            uplinkBytes,
+		"downlinkBytes":          downlinkBytes,
+		"currentBalance":         currentBalance,
+		"remainingIncludedQuota": remainingQuota,
+		"suspendState":           suspendState,
+		"throttleState":          throttleState,
+		"arrears":                arrears,
+		"lastBucketAt":           lastBucketAt,
+		"syncDelaySeconds":       syncDelaySeconds,
+	})
+}
+
+func (h *handler) accountUsageBuckets(c *gin.Context) {
+	user, ok := h.requireAuthenticatedUser(c)
+	if !ok {
+		return
+	}
+
+	start, err := parseOptionalTime(c.Query("start"))
+	if err != nil {
+		respondError(c, http.StatusBadRequest, "invalid_start", "start must be RFC3339")
+		return
+	}
+	end, err := parseOptionalTime(c.Query("end"))
+	if err != nil {
+		respondError(c, http.StatusBadRequest, "invalid_end", "end must be RFC3339")
+		return
+	}
+
+	buckets, err := h.store.ListTrafficMinuteBucketsByAccount(c.Request.Context(), user.ID, start, end)
+	if err != nil {
+		respondError(c, http.StatusInternalServerError, "usage_buckets_unavailable", "failed to load usage buckets")
+		return
+	}
+
+	c.JSON(http.StatusOK, gin.H{
+		"accountUuid": user.ID,
+		"buckets":     buckets,
+	})
+}
+
+func (h *handler) accountBillingSummary(c *gin.Context) {
+	user, ok := h.requireAuthenticatedUser(c)
+	if !ok {
+		return
+	}
+
+	ledger, err := h.store.ListBillingLedgerByAccount(c.Request.Context(), user.ID, 20)
+	if err != nil {
+		respondError(c, http.StatusInternalServerError, "billing_summary_unavailable", "failed to load billing summary")
+		return
+	}
+
+	var quota *store.AccountQuotaState
+	if snapshot, err := h.store.GetAccountQuotaState(c.Request.Context(), user.ID); err == nil {
+		quota = snapshot
+	}
+
+	c.JSON(http.StatusOK, gin.H{
+		"accountUuid": user.ID,
+		"quotaState":  quota,
+		"ledger":      ledger,
+	})
+}
+
+func (h *handler) accountPolicy(c *gin.Context) {
+	user, ok := h.requireAuthenticatedUser(c)
+	if !ok {
+		return
+	}
+
+	policy, err := h.store.GetLatestAccountPolicySnapshot(c.Request.Context(), user.ID)
+	if err != nil {
+		respondError(c, http.StatusNotFound, "policy_not_found", "account policy snapshot is not available")
+		return
+	}
+
+	c.JSON(http.StatusOK, gin.H{
+		"accountUuid":        policy.AccountUUID,
+		"policyVersion":      policy.PolicyVersion,
+		"authState":          policy.AuthState,
+		"rateProfile":        policy.RateProfile,
+		"connProfile":        policy.ConnProfile,
+		"eligibleNodeGroups": policy.EligibleNodeGroups,
+		"preferredStrategy":  policy.PreferredStrategy,
+		"degradeMode":        policy.DegradeMode,
+		"expiresAt":          policy.ExpiresAt,
+	})
+}
+
+func (h *handler) adminTrafficNodes(c *gin.Context) {
+	if _, ok := h.requireAdminPermission(c, permissionAdminAgentsStatus); !ok {
+		return
+	}
+
+	nodes, err := h.store.ListLatestNodeHealthSnapshots(c.Request.Context())
+	if err != nil {
+		respondError(c, http.StatusInternalServerError, "node_health_unavailable", "failed to load node health snapshots")
+		return
+	}
+
+	c.JSON(http.StatusOK, gin.H{"nodes": nodes})
+}
+
+func (h *handler) adminTrafficAccount(c *gin.Context) {
+	if _, ok := h.requireAdminPermission(c, permissionAdminUsersListRead); !ok {
+		return
+	}
+
+	accountUUID := strings.TrimSpace(c.Param("uuid"))
+	if accountUUID == "" {
+		respondError(c, http.StatusBadRequest, "account_uuid_required", "account uuid is required")
+		return
+	}
+
+	buckets, err := h.store.ListTrafficMinuteBucketsByAccount(c.Request.Context(), accountUUID, time.Time{}, time.Time{})
+	if err != nil {
+		respondError(c, http.StatusInternalServerError, "account_traffic_unavailable", "failed to load account traffic")
+		return
+	}
+	ledger, err := h.store.ListBillingLedgerByAccount(c.Request.Context(), accountUUID, 20)
+	if err != nil {
+		respondError(c, http.StatusInternalServerError, "account_billing_unavailable", "failed to load account billing")
+		return
+	}
+	policy, _ := h.store.GetLatestAccountPolicySnapshot(c.Request.Context(), accountUUID)
+	quota, _ := h.store.GetAccountQuotaState(c.Request.Context(), accountUUID)
+
+	c.JSON(http.StatusOK, gin.H{
+		"accountUuid": accountUUID,
+		"buckets":     buckets,
+		"ledger":      ledger,
+		"policy":      policy,
+		"quotaState":  quota,
+	})
+}
+
+func (h *handler) adminCollectorStatus(c *gin.Context) {
+	if _, ok := h.requireAdminPermission(c, permissionAdminAgentsStatus); !ok {
+		return
+	}
+
+	checkpoints, err := h.store.ListTrafficStatCheckpoints(c.Request.Context())
+	if err != nil {
+		respondError(c, http.StatusInternalServerError, "collector_status_unavailable", "failed to load collector checkpoints")
+		return
+	}
+	buckets, err := h.store.ListTrafficMinuteBuckets(c.Request.Context())
+	if err != nil {
+		respondError(c, http.StatusInternalServerError, "collector_status_unavailable", "failed to load collector buckets")
+		return
+	}
+
+	var latestCheckpointAt *time.Time
+	for _, checkpoint := range checkpoints {
+		timestamp := checkpoint.LastSeenAt.UTC()
+		if latestCheckpointAt == nil || timestamp.After(*latestCheckpointAt) {
+			latestCheckpointAt = &timestamp
+		}
+	}
+
+	c.JSON(http.StatusOK, gin.H{
+		"checkpointCount":    len(checkpoints),
+		"minuteBucketCount":  len(buckets),
+		"latestCheckpointAt": latestCheckpointAt,
+	})
+}
+
+func (h *handler) adminSchedulerStatus(c *gin.Context) {
+	if _, ok := h.requireAdminPermission(c, permissionAdminAgentsStatus); !ok {
+		return
+	}
+
+	limit := 20
+	if raw := strings.TrimSpace(c.Query("limit")); raw != "" {
+		if parsed, err := strconv.Atoi(raw); err == nil && parsed > 0 && parsed <= 200 {
+			limit = parsed
+		}
+	}
+
+	decisions, err := h.store.ListRecentSchedulerDecisions(c.Request.Context(), limit)
+	if err != nil {
+		respondError(c, http.StatusInternalServerError, "scheduler_status_unavailable", "failed to load scheduler decisions")
+		return
+	}
+
+	c.JSON(http.StatusOK, gin.H{"decisions": decisions})
+}
+
+func (h *handler) internalAccountPolicy(c *gin.Context) {
+	accountUUID := strings.TrimSpace(c.Param("accountUUID"))
+	if accountUUID == "" {
+		respondError(c, http.StatusBadRequest, "account_uuid_required", "account uuid is required")
+		return
+	}
+
+	policy, err := h.store.GetLatestAccountPolicySnapshot(c.Request.Context(), accountUUID)
+	if err != nil {
+		respondError(c, http.StatusNotFound, "policy_not_found", "account policy snapshot is not available")
+		return
+	}
+
+	c.JSON(http.StatusOK, policy)
+}
+
+func (h *handler) internalNodeHeartbeat(c *gin.Context) {
+	var req nodeHeartbeatRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		respondError(c, http.StatusBadRequest, "invalid_request", "invalid heartbeat payload")
+		return
+	}
+
+	nodeID := strings.TrimSpace(req.NodeID)
+	if nodeID == "" {
+		respondError(c, http.StatusBadRequest, "node_id_required", "node id is required")
+		return
+	}
+
+	sampledAt, err := parseOptionalTime(req.SampledAt)
+	if err != nil {
+		respondError(c, http.StatusBadRequest, "invalid_sampled_at", "sampledAt must be RFC3339")
+		return
+	}
+	if sampledAt.IsZero() {
+		sampledAt = time.Now().UTC()
+	}
+
+	if err := h.store.UpsertNodeHealthSnapshot(c.Request.Context(), &store.NodeHealthSnapshot{
+		NodeID:            nodeID,
+		Region:            strings.TrimSpace(req.Region),
+		LineCode:          strings.TrimSpace(req.LineCode),
+		PricingGroup:      strings.TrimSpace(req.PricingGroup),
+		StatsEnabled:      req.StatsEnabled,
+		XrayRevision:      strings.TrimSpace(req.XrayRevision),
+		Healthy:           req.Healthy,
+		LatencyMS:         req.LatencyMS,
+		ErrorRate:         req.ErrorRate,
+		ActiveConnections: req.ActiveConnections,
+		HealthScore:       req.HealthScore,
+		SampledAt:         sampledAt,
+	}); err != nil {
+		respondError(c, http.StatusInternalServerError, "heartbeat_persist_failed", "failed to persist node heartbeat")
+		return
+	}
+
+	c.Status(http.StatusNoContent)
+}
diff --git a/api/accounting_test.go b/api/accounting_test.go
new file mode 100644
index 0000000..96c4a13
--- /dev/null
+++ b/api/accounting_test.go
@@ -0,0 +1,206 @@
+package api
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+
+	"github.com/gin-gonic/gin"
+
+	"account/internal/agentserver"
+	"account/internal/store"
+)
+
+func TestAgentUsersUseAccountUUIDAsStatsEmail(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	st := store.NewMemoryStore()
+	ctx := context.Background()
+
+	if err := st.CreateUser(ctx, &store.User{
+		Name:          "Stats User",
+		Email:         "stats@example.com",
+		PasswordHash:  "hashed",
+		EmailVerified: true,
+		Role:          store.RoleUser,
+		Level:         store.LevelUser,
+		Active:        true,
+		ProxyUUID:     "proxy-user-id",
+	}); err != nil {
+		t.Fatalf("create user: %v", err)
+	}
+
+	user, err := st.GetUserByEmail(ctx, "stats@example.com")
+	if err != nil {
+		t.Fatalf("get user: %v", err)
+	}
+
+	registry, err := agentserver.NewRegistry(agentserver.Config{
+		Credentials: []agentserver.Credential{{
+			ID:    "*",
+			Name:  "test-agent",
+			Token: "agent-token",
+		}},
+	})
+	if err != nil {
+		t.Fatalf("new registry: %v", err)
+	}
+
+	router := gin.New()
+	RegisterRoutes(router, WithStore(st), WithAgentRegistry(registry), WithEmailVerification(false))
+
+	req := httptest.NewRequest(http.MethodGet, "/api/agent-server/v1/users", nil)
+	req.Header.Set("Authorization", "Bearer agent-token")
+	req.Header.Set("X-Agent-ID", "hk-xhttp.svc.plus")
+	rec := httptest.NewRecorder()
+	router.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("unexpected status: %d body=%s", rec.Code, rec.Body.String())
+	}
+
+	var payload struct {
+		Clients []struct {
+			ID    string `json:"id"`
+			Email string `json:"email"`
+		} `json:"clients"`
+	}
+	if err := json.Unmarshal(rec.Body.Bytes(), &payload); err != nil {
+		t.Fatalf("decode payload: %v", err)
+	}
+
+	for _, client := range payload.Clients {
+		if client.Email == user.ID {
+			return
+		}
+	}
+
+	t.Fatalf("expected stats email %q in payload, got %#v", user.ID, payload.Clients)
+}
+
+func TestAccountUsageAndPolicyEndpoints(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	st := store.NewMemoryStore()
+	ctx := context.Background()
+
+	if err := st.CreateUser(ctx, &store.User{
+		Name:          "Billing User",
+		Email:         "billing@example.com",
+		PasswordHash:  "hashed",
+		EmailVerified: true,
+		Role:          store.RoleUser,
+		Level:         store.LevelUser,
+		Active:        true,
+	}); err != nil {
+		t.Fatalf("create user: %v", err)
+	}
+
+	user, err := st.GetUserByEmail(ctx, "billing@example.com")
+	if err != nil {
+		t.Fatalf("get user: %v", err)
+	}
+
+	sessionToken := "usage-session-token"
+	if err := st.CreateSession(ctx, sessionToken, user.ID, time.Now().UTC().Add(time.Hour)); err != nil {
+		t.Fatalf("create session: %v", err)
+	}
+
+	bucketStart := time.Date(2026, 4, 1, 10, 30, 0, 0, time.UTC)
+	if err := st.UpsertTrafficMinuteBucket(ctx, &store.TrafficMinuteBucket{
+		BucketStart:   bucketStart,
+		NodeID:        "node-a",
+		AccountUUID:   user.ID,
+		Region:        "hk",
+		LineCode:      "premium",
+		UplinkBytes:   128,
+		DownlinkBytes: 256,
+		TotalBytes:    384,
+		Multiplier:    1.5,
+		RatingStatus:  store.RatingStatusRated,
+	}); err != nil {
+		t.Fatalf("upsert bucket: %v", err)
+	}
+
+	if err := st.UpsertAccountQuotaState(ctx, &store.AccountQuotaState{
+		AccountUUID:            user.ID,
+		RemainingIncludedQuota: 2048,
+		CurrentBalance:         87.5,
+		Arrears:                false,
+		ThrottleState:          "normal",
+		SuspendState:           "active",
+		EffectiveAt:            time.Now().UTC(),
+	}); err != nil {
+		t.Fatalf("upsert quota state: %v", err)
+	}
+
+	if err := st.UpsertAccountPolicySnapshot(ctx, &store.AccountPolicySnapshot{
+		AccountUUID:        user.ID,
+		PolicyVersion:      "policy-v1",
+		AuthState:          "active",
+		RateProfile:        "standard",
+		ConnProfile:        "standard",
+		EligibleNodeGroups: []string{"hk-premium"},
+		PreferredStrategy:  "ewma",
+		DegradeMode:        "fallback",
+		ExpiresAt:          time.Now().UTC().Add(5 * time.Minute),
+	}); err != nil {
+		t.Fatalf("upsert policy: %v", err)
+	}
+
+	router := gin.New()
+	RegisterRoutes(router, WithStore(st), WithEmailVerification(false))
+
+	req := httptest.NewRequest(http.MethodGet, "/api/account/usage/summary", nil)
+	req.Header.Set("Authorization", "Bearer "+sessionToken)
+	rec := httptest.NewRecorder()
+	router.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("usage summary status: %d body=%s", rec.Code, rec.Body.String())
+	}
+
+	var usagePayload struct {
+		AccountUUID string `json:"accountUuid"`
+		TotalBytes  int64  `json:"totalBytes"`
+	}
+	if err := json.Unmarshal(rec.Body.Bytes(), &usagePayload); err != nil {
+		t.Fatalf("decode usage payload: %v", err)
+	}
+	if usagePayload.AccountUUID != user.ID {
+		t.Fatalf("expected account uuid %q, got %q", user.ID, usagePayload.AccountUUID)
+	}
+	if usagePayload.TotalBytes != 384 {
+		t.Fatalf("expected total bytes 384, got %d", usagePayload.TotalBytes)
+	}
+
+	policyReq := httptest.NewRequest(http.MethodGet, "/api/account/policy", nil)
+	policyReq.Header.Set("Authorization", "Bearer "+sessionToken)
+	policyRec := httptest.NewRecorder()
+	router.ServeHTTP(policyRec, policyReq)
+
+	if policyRec.Code != http.StatusOK {
+		t.Fatalf("policy status: %d body=%s", policyRec.Code, policyRec.Body.String())
+	}
+
+	var policyPayload struct {
+		AccountUUID        string   `json:"accountUuid"`
+		PreferredStrategy  string   `json:"preferredStrategy"`
+		EligibleNodeGroups []string `json:"eligibleNodeGroups"`
+	}
+	if err := json.Unmarshal(policyRec.Body.Bytes(), &policyPayload); err != nil {
+		t.Fatalf("decode policy payload: %v", err)
+	}
+	if policyPayload.AccountUUID != user.ID {
+		t.Fatalf("expected policy account uuid %q, got %q", user.ID, policyPayload.AccountUUID)
+	}
+	if policyPayload.PreferredStrategy != "ewma" {
+		t.Fatalf("expected preferred strategy ewma, got %q", policyPayload.PreferredStrategy)
+	}
+	if len(policyPayload.EligibleNodeGroups) != 1 || policyPayload.EligibleNodeGroups[0] != "hk-premium" {
+		t.Fatalf("unexpected eligible node groups %#v", policyPayload.EligibleNodeGroups)
+	}
+}
diff --git a/api/admin_users_metrics.go b/api/admin_users_metrics.go
index be63fd6..eb56c3a 100644
--- a/api/admin_users_metrics.go
+++ b/api/admin_users_metrics.go
@@ -189,6 +189,10 @@ func registerAdminRoutes(group *gin.RouterGroup, h *handler) {
 	admin := group.Group("/admin")
 	admin.GET("/users/metrics", h.adminUsersMetrics)
 	admin.GET("/agents/status", h.adminAgentStatus)
+	admin.GET("/traffic/nodes", h.adminTrafficNodes)
+	admin.GET("/traffic/accounts/:uuid", h.adminTrafficAccount)
+	admin.GET("/collector/status", h.adminCollectorStatus)
+	admin.GET("/scheduler/status", h.adminSchedulerStatus)
 
 	// User management
 	admin.POST("/users", h.createCustomUser)
diff --git a/api/agent_server.go b/api/agent_server.go
index 7a2ac6a..55db934 100644
--- a/api/agent_server.go
+++ b/api/agent_server.go
@@ -9,6 +9,7 @@ import (
 
 	"account/internal/agentproto"
 	"account/internal/agentserver"
+	"account/internal/store"
 	"account/internal/xrayconfig"
 )
 
@@ -75,7 +76,7 @@ func (h *handler) listAgentUsers(c *gin.Context) {
 			if id != "" {
 				clients = append(clients, xrayconfig.Client{
 					ID:    id,
-					Email: strings.TrimSpace(sandboxUser.Email),
+					Email: strings.TrimSpace(sandboxUser.ID),
 					Flow:  xrayconfig.DefaultFlow,
 				})
 			}
@@ -91,7 +92,7 @@ func (h *handler) listAgentUsers(c *gin.Context) {
 		}
 		clients = append(clients, xrayconfig.Client{
 			ID:    id,
-			Email: strings.TrimSpace(u.Email),
+			Email: strings.TrimSpace(u.ID),
 			Flow:  xrayconfig.DefaultFlow,
 		})
 	}
@@ -143,6 +144,22 @@ func (h *handler) reportAgentStatus(c *gin.Context) {
 	// Ensure report uses the resolved agent id.
 	report.AgentID = identity.ID
 	h.agentRegistry.ReportStatus(identity, report)
+	if h.store != nil {
+		nodeID := strings.TrimSpace(report.Xray.NodeID)
+		if nodeID == "" {
+			nodeID = identity.ID
+		}
+		_ = h.store.UpsertNodeHealthSnapshot(c.Request.Context(), &store.NodeHealthSnapshot{
+			NodeID:       nodeID,
+			Region:       strings.TrimSpace(report.Xray.Region),
+			LineCode:     strings.TrimSpace(report.Xray.LineCode),
+			PricingGroup: strings.TrimSpace(report.Xray.PricingGroup),
+			StatsEnabled: report.Xray.StatsEnabled,
+			XrayRevision: strings.TrimSpace(report.Xray.XrayRevision),
+			Healthy:      report.Healthy,
+			SampledAt:    time.Now().UTC(),
+		})
+	}
 
 	c.Status(http.StatusNoContent)
 }
diff --git a/api/api.go b/api/api.go
index 640d308..5c4204b 100644
--- a/api/api.go
+++ b/api/api.go
@@ -402,6 +402,8 @@ func RegisterRoutes(r *gin.Engine, opts ...Option) {
 	internalGroup.Use(auth.InternalAuthMiddleware())
 	internalGroup.GET("/public-overview", h.internalPublicOverview)
 	internalGroup.GET("/sandbox/guest", h.internalSandboxGuest)
+	internalGroup.GET("/policy/:accountUUID", h.internalAccountPolicy)
+	internalGroup.POST("/nodes/heartbeat", h.internalNodeHeartbeat)
 
 	// Public /api routes for admin/management (expected by frontend at /api/admin/...)
 	apiGroup := r.Group("/api")
@@ -419,6 +421,12 @@ func RegisterRoutes(r *gin.Engine, opts ...Option) {
 	agentServerGroup.GET("/users", h.listAgentUsers)
 	agentServerGroup.POST("/status", h.reportAgentStatus)
 
+	accountGroup := r.Group("/api/account")
+	accountGroup.GET("/usage/summary", h.accountUsageSummary)
+	accountGroup.GET("/usage/buckets", h.accountUsageBuckets)
+	accountGroup.GET("/billing/summary", h.accountBillingSummary)
+	accountGroup.GET("/policy", h.accountPolicy)
+
 	// Legacy alias kept for backward compatibility.
 	agentGroup := r.Group("/api/agent")
 	agentGroup.GET("/nodes", h.listAgentNodes)
diff --git a/api/api_test.go b/api/api_test.go
index 6e50b37..300beaa 100644
--- a/api/api_test.go
+++ b/api/api_test.go
@@ -266,6 +266,10 @@ func TestAgentServerUsers_DefaultSyncIncludesSandboxAndRegularUsers(t *testing.T
 	}
 
 	// Ensure normal user is "expired" per proxy UUID expiry metadata.
+	sandbox, err := st.GetUserByEmail(ctx, "sandbox@svc.plus")
+	if err != nil {
+		t.Fatalf("get sandbox user: %v", err)
+	}
 	normal, err := st.GetUserByEmail(ctx, "user@example.com")
 	if err != nil {
 		t.Fatalf("get normal user: %v", err)
@@ -314,10 +318,10 @@ func TestAgentServerUsers_DefaultSyncIncludesSandboxAndRegularUsers(t *testing.T
 	seenSandbox := false
 	seenNormal := false
 	for _, c := range payload.Clients {
-		if c.Email == "sandbox@svc.plus" && strings.TrimSpace(c.ID) != "" {
+		if c.Email == sandbox.ID && strings.TrimSpace(c.ID) != "" {
 			seenSandbox = true
 		}
-		if c.Email == "user@example.com" && strings.TrimSpace(c.ID) != "" {
+		if c.Email == normal.ID && strings.TrimSpace(c.ID) != "" {
 			seenNormal = true
 		}
 	}
diff --git a/api/config_sync.go b/api/config_sync.go
index 9bc2e40..536af23 100644
--- a/api/config_sync.go
+++ b/api/config_sync.go
@@ -120,23 +120,23 @@ func (h *handler) respondSyncConfigSnapshot(c *gin.Context) {
 				"vless_uri":    vlessURI,
 			})
 			nodes = append(nodes, gin.H{
-				"id":              nodeID,
-				"name":            nodeName,
-				"display_name":    nodeName,
-				"remark":          nodeName,
-				"host":            host,
-				"protocol":        "vless",
-				"transport":       "xhttp",
-				"security":        "tls",
-				"address":         host,
-				"port":            443,
-				"server_name":     host,
-				"uuid":            proxyUUID,
-				"flow":            "",
-				"source":          "server",
-				"country_code":    countryCode,
-				"updated_at":      updatedAt,
-				"vless_uri":       vlessURI,
+				"id":               nodeID,
+				"name":             nodeName,
+				"display_name":     nodeName,
+				"remark":           nodeName,
+				"host":             host,
+				"protocol":         "vless",
+				"transport":        "xhttp",
+				"security":         "tls",
+				"address":          host,
+				"port":             443,
+				"server_name":      host,
+				"uuid":             proxyUUID,
+				"flow":             "",
+				"source":           "server",
+				"country_code":     countryCode,
+				"updated_at":       updatedAt,
+				"vless_uri":        vlessURI,
 				"uri_scheme_xhttp": vlessURI,
 			})
 		}
@@ -227,7 +227,7 @@ func (h *handler) renderUserXrayConfig(user *store.User) (string, string, []stri
 	}
 	clients := []xrayconfig.Client{{
 		ID:    clientID,
-		Email: strings.TrimSpace(user.Email),
+		Email: strings.TrimSpace(user.ID),
 		Flow:  xrayconfig.DefaultFlow,
 	}}
 
diff --git a/docs/architecture/accounts/overview.md b/docs/architecture/accounts/overview.md
new file mode 100644
index 0000000..c3d6154
--- /dev/null
+++ b/docs/architecture/accounts/overview.md
@@ -0,0 +1,163 @@
+# accounts.svc.plus Architecture
+
+## Scope
+
+`accounts.svc.plus` is the identity and account control service. It owns user authentication, session issuance, MFA, subscription state, admin settings, sandbox behavior, and agent registry endpoints.
+
+## Architecture
+
+```mermaid
+flowchart TB
+  subgraph Public["Public auth surface"]
+    HZ["GET /healthz"]
+    REG["POST /api/auth/register\nPOST /api/auth/register/send\nPOST /api/auth/register/verify"]
+    LOGIN["POST /api/auth/login\nPOST /api/auth/mfa/verify\nPOST /api/auth/token/exchange\nGET /api/auth/oauth/login/:provider\nGET /api/auth/oauth/callback/:provider\nPOST /api/auth/token/refresh\nPOST /api/auth/refresh"]
+    PUBLIC["GET /api/auth/mfa/status\nGET /api/auth/sync/config\nPOST /api/auth/sync/ack\nGET /api/auth/homepage-video\nGET /api/auth/sandbox/binding"]
+    WEBHOOK["POST /api/billing/stripe/webhook"]
+  end
+
+  subgraph Session["Session protected"]
+    SESSION["GET /api/auth/session\nDELETE /api/auth/session\nGET/PUT /api/auth/xworkmate/profile"]
+    MFA["POST /api/auth/mfa/totp/provision\nPOST /api/auth/mfa/totp/verify\nPOST /api/auth/mfa/disable"]
+    RESET["POST /api/auth/password/reset\nPOST /api/auth/password/reset/confirm"]
+    BILLING["GET/POST /api/auth/subscriptions\nPOST /api/auth/subscriptions/cancel\nPOST /api/auth/stripe/checkout\nPOST /api/auth/stripe/portal"]
+    SYNC["POST /api/auth/config/sync"]
+    ADMINAUTH["GET/POST /api/auth/admin/settings\nGET/PUT /api/auth/admin/homepage-video"]
+    USEROPS["GET /api/auth/users\nGET/POST /api/auth/admin/users/metrics\nPOST /api/auth/admin/users\nPOST /api/auth/admin/users/:userId/role\nDELETE /api/auth/admin/users/:userId/role\nPOST /api/auth/admin/users/:userId/pause\nPOST /api/auth/admin/users/:userId/resume\nDELETE /api/auth/admin/users/:userId\nPOST /api/auth/admin/users/:userId/renew-uuid"]
+    ADMINMORE["POST /api/auth/admin/tenants/bootstrap\nGET/POST/DELETE /api/auth/admin/blacklist\nGET/POST /api/auth/admin/sandbox/binding\nPOST /api/auth/admin/sandbox/bind\nPOST /api/auth/admin/assume\nPOST /api/auth/admin/assume/revert\nGET /api/auth/admin/assume/status"]
+  end
+
+  subgraph Internal["Internal / agent surfaces"]
+    INTERNAL["GET /api/internal/public-overview\nGET /api/internal/sandbox/guest"]
+    AGENT["GET /api/agent-server/v1/users\nPOST /api/agent-server/v1/status\nGET /api/agent/nodes (legacy)"]
+  end
+
+  subgraph DB["PostgreSQL"]
+    USERS[("users")]
+    IDS[("identities")]
+    SESSIONS[("sessions")]
+    SUBS[("subscriptions")]
+    SETTINGS[("admin_settings")]
+    ROLES[("rbac_roles")]
+    PERMS[("rbac_permissions")]
+    ROLEPERMS[("rbac_role_permissions")]
+    BLACKLIST[("email_blacklist")]
+    AGENTS[("agents")]
+    NODES[("nodes")]
+  end
+
+  REG --> USERS
+  LOGIN --> USERS
+  LOGIN --> IDS
+  SESSION --> SESSIONS
+  MFA --> USERS
+  RESET --> USERS
+  BILLING --> SUBS
+  ADMINAUTH --> SETTINGS
+  USEROPS --> USERS
+  USEROPS --> ROLES
+  USEROPS --> PERMS
+  USEROPS --> ROLEPERMS
+  ADMINMORE --> USERS
+  ADMINMORE --> BLACKLIST
+  ADMINMORE --> NODES
+  AGENT --> USERS
+  AGENT --> AGENTS
+  AGENT --> NODES
+  INTERNAL --> USERS
+  WEBHOOK --> SUBS
+```
+
+## API Matrix
+
+### Public auth and bootstrapping
+
+| Name | Path | Purpose | Database / table | Auth mode |
+| --- | --- | --- | --- | --- |
+| Health | `/healthz` | Liveness check | N/A | none |
+| Register | `/api/auth/register` | Create new account | `users`, `identities` | none |
+| Register email | `/api/auth/register/send` | Send registration verification email | `users` | none |
+| Register verify | `/api/auth/register/verify` | Confirm registration code / email | `users` | none |
+| Login | `/api/auth/login` | Issue session token or MFA challenge | `users`, `sessions` | none |
+| MFA verify | `/api/auth/mfa/verify` | Finish MFA login | `users`, `sessions` | none |
+| OAuth login / callback | `/api/auth/oauth/login/:provider`, `/api/auth/oauth/callback/:provider` | OAuth entry and callback | `users`, `identities`, `sessions` | none |
+| Token exchange | `/api/auth/token/exchange` | One-time OAuth exchange to session token | `sessions` | none |
+| Token refresh | `/api/auth/token/refresh`, `/api/auth/refresh` | Refresh access token | `sessions` | bearer/refresh token |
+| MFA status | `/api/auth/mfa/status` | Check whether MFA is required | `users` | none |
+| Sync config | `/api/auth/sync/config`, `/api/auth/sync/ack` | Sync configuration snapshot / ack | `users`, `admin_settings` | none |
+| Public homepage video | `/api/auth/homepage-video` | Read public homepage video config | `admin_settings` | none |
+| Sandbox binding public read | `/api/auth/sandbox/binding` | Read sandbox node binding for guest/demo | `nodes`, `users` | none or session or internal token |
+
+### Session protected account actions
+
+| Name | Path | Purpose | Database / table | Auth mode |
+| --- | --- | --- | --- | --- |
+| Session | `/api/auth/session` | Read current session user | `sessions`, `users` | `Authorization: Bearer <session token>` |
+| Logout | `DELETE /api/auth/session` | Revoke local session cookie / token | `sessions` | session token |
+| XWorkmate profile | `/api/auth/xworkmate/profile` | Read/update per-user profile settings | `users`, `xworkmate_profiles` (migration-backed) | session token |
+| MFA setup | `/api/auth/mfa/totp/provision`, `/api/auth/mfa/totp/verify`, `/api/auth/mfa/disable` | TOTP setup and disable | `users` | session token |
+| Password reset | `/api/auth/password/reset`, `/api/auth/password/reset/confirm` | Reset password flow | `users` | session token |
+| Subscriptions | `/api/auth/subscriptions`, `/api/auth/subscriptions/cancel` | Manage subscription records | `subscriptions`, `users` | session token |
+| Stripe checkout / portal | `/api/auth/stripe/checkout`, `/api/auth/stripe/portal` | Open Stripe checkout and customer portal | `subscriptions`, `users` | session token |
+| Config sync | `/api/auth/config/sync` | Push client config state | `users`, `admin_settings` | session token |
+
+### Admin and operator actions
+
+| Name | Path | Purpose | Database / table | Auth mode |
+| --- | --- | --- | --- | --- |
+| Admin settings | `/api/auth/admin/settings` | Read / update permission matrix | `admin_settings`, `rbac_*` | session token + admin/operator |
+| Homepage video admin | `/api/auth/admin/homepage-video` | Update homepage video settings | `admin_settings` | session token + admin/operator |
+| User metrics | `/api/auth/admin/users/metrics` | Count and summary of users | `users` | session token + admin/operator |
+| Create user | `/api/auth/admin/users` | Create custom user | `users`, `sessions` | session token + admin/operator |
+| Update role | `/api/auth/admin/users/:userId/role` | Change a user role | `users` | session token + admin/operator |
+| Reset role | `DELETE /api/auth/admin/users/:userId/role` | Reset a user role | `users` | session token + admin/operator |
+| Pause / resume | `/api/auth/admin/users/:userId/pause`, `/api/auth/admin/users/:userId/resume` | Disable / re-enable user | `users` | session token + admin/operator |
+| Delete user | `DELETE /api/auth/admin/users/:userId` | Delete user | `users`, `sessions`, `identities` | session token + admin/operator |
+| Renew proxy UUID | `/api/auth/admin/users/:userId/renew-uuid` | Rotate proxy UUID | `users` | session token + admin/operator |
+| Tenant bootstrap | `/api/auth/admin/tenants/bootstrap` | Bootstrap tenant records | `tenants`, `tenant_memberships` (migration-backed) | session token + admin/operator |
+| Blacklist | `/api/auth/admin/blacklist`, `/api/auth/admin/blacklist/:email` | Manage blocked email list | `email_blacklist` | session token + admin/operator |
+| Sandbox binding admin | `/api/auth/admin/sandbox/binding`, `/api/auth/admin/sandbox/bind` | Bind sandbox node | `nodes`, `users` | session token + root/admin rules |
+| Assume sandbox | `/api/auth/admin/assume`, `/api/auth/admin/assume/revert`, `/api/auth/admin/assume/status` | Switch to / from sandbox identity | `sessions`, `users` | session token + root-only allowlist |
+| Users list | `/api/auth/users` | List users | `users` | session token + auth middleware |
+
+### Internal and agent endpoints
+
+| Name | Path | Purpose | Database / table | Auth mode |
+| --- | --- | --- | --- | --- |
+| Internal overview | `/api/internal/public-overview` | Public overview for internal clients | `users`, `admin_settings` | `X-Service-Token` |
+| Sandbox guest | `/api/internal/sandbox/guest` | Return guest/demo identity snapshot | `users`, `nodes`, `sessions` | `X-Service-Token` |
+| Agent users | `/api/agent-server/v1/users` | Provide Xray client list to agent runtime | `users`, `agents`, `nodes` | `Authorization: Bearer <agent token>` + optional `X-Agent-ID` |
+| Agent status | `/api/agent-server/v1/status` | Receive agent heartbeat and sync status | `agents`, `nodes` | `Authorization: Bearer <agent token>` + optional `X-Agent-ID` |
+| Legacy agent alias | `/api/agent/nodes` | Backward-compatible alias for node list | `nodes` | same as agent-server |
+
+### Webhook
+
+| Name | Path | Purpose | Database / table | Auth mode |
+| --- | --- | --- | --- | --- |
+| Stripe webhook | `/api/billing/stripe/webhook` | Receive Stripe events | `subscriptions` | Stripe signature verification |
+
+## Data Model Notes
+
+- `users` is the main identity record and also stores roles, groups, permissions, MFA state, proxy UUID, and activity flags.
+- `identities` links OAuth providers to users.
+- `sessions` stores session tokens with expiry.
+- `subscriptions` stores billing state and provider references.
+- `admin_settings` stores a versioned permission matrix.
+- `rbac_roles`, `rbac_permissions`, and `rbac_role_permissions` store the RBAC catalog.
+- `agents` stores agent runtime status snapshots.
+- `nodes` stores proxy / node inventory.
+- `email_blacklist` stores blocked addresses.
+- The codebase also defines migration-backed tenant / XWorkmate models such as `tenants`, `tenant_domains`, `tenant_memberships`, and `xworkmate_profiles`; those tables are part of the broader account domain even though they are not declared in the checked-in `sql/schema.sql` snapshot.
+
+## Auth Layers
+
+1. Public routes do not require a session token.
+2. Session protected routes require `Authorization: Bearer <session token>` and active-user validation.
+3. Admin routes add role / permission checks on top of session auth.
+4. Internal routes require `X-Service-Token`.
+5. Agent routes accept agent credential tokens and optional `X-Agent-ID`.
+
+## Notes
+
+- Some frontend BFF endpoints use the same account service backend but shape cookies and auth state for browser usage.
+- `api/agent-server/v1/*` is the canonical route family for the console and agent runtime.
diff --git a/internal/agentproto/types.go b/internal/agentproto/types.go
index d69d9e7..48e3b03 100644
--- a/internal/agentproto/types.go
+++ b/internal/agentproto/types.go
@@ -28,8 +28,14 @@ type StatusReport struct {
 
 // XrayStatus describes the synchronisation state of the managed Xray process.
 type XrayStatus struct {
-	Running    bool       `json:"running"`
-	Clients    int        `json:"clients"`
-	LastSync   *time.Time `json:"lastSync,omitempty"`
-	ConfigHash string     `json:"configHash,omitempty"`
+	Running      bool       `json:"running"`
+	Clients      int        `json:"clients"`
+	LastSync     *time.Time `json:"lastSync,omitempty"`
+	ConfigHash   string     `json:"configHash,omitempty"`
+	NodeID       string     `json:"nodeId,omitempty"`
+	Region       string     `json:"region,omitempty"`
+	LineCode     string     `json:"lineCode,omitempty"`
+	PricingGroup string     `json:"pricingGroup,omitempty"`
+	StatsEnabled bool       `json:"statsEnabled"`
+	XrayRevision string     `json:"xrayRevision,omitempty"`
 }
diff --git a/internal/store/accounting_memory.go b/internal/store/accounting_memory.go
new file mode 100644
index 0000000..8e9ddf6
--- /dev/null
+++ b/internal/store/accounting_memory.go
@@ -0,0 +1,376 @@
+package store
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/google/uuid"
+)
+
+func checkpointKey(nodeID, accountUUID string) string {
+	return strings.TrimSpace(nodeID) + "::" + strings.TrimSpace(accountUUID)
+}
+
+func bucketKey(bucketStart time.Time, nodeID, accountUUID, region, lineCode string) string {
+	return fmt.Sprintf("%s::%s::%s::%s::%s",
+		bucketStart.UTC().Format(time.RFC3339),
+		strings.TrimSpace(nodeID),
+		strings.TrimSpace(accountUUID),
+		strings.TrimSpace(region),
+		strings.TrimSpace(lineCode),
+	)
+}
+
+func cloneCheckpoint(src *TrafficStatCheckpoint) *TrafficStatCheckpoint {
+	if src == nil {
+		return nil
+	}
+	copy := *src
+	return &copy
+}
+
+func cloneBucket(src *TrafficMinuteBucket) *TrafficMinuteBucket {
+	if src == nil {
+		return nil
+	}
+	copy := *src
+	return &copy
+}
+
+func cloneLedgerEntry(src *BillingLedgerEntry) *BillingLedgerEntry {
+	if src == nil {
+		return nil
+	}
+	copy := *src
+	return &copy
+}
+
+func cloneQuotaState(src *AccountQuotaState) *AccountQuotaState {
+	if src == nil {
+		return nil
+	}
+	copy := *src
+	if src.LastRatedBucketAt != nil {
+		last := src.LastRatedBucketAt.UTC()
+		copy.LastRatedBucketAt = &last
+	}
+	return &copy
+}
+
+func clonePolicySnapshot(src *AccountPolicySnapshot) *AccountPolicySnapshot {
+	if src == nil {
+		return nil
+	}
+	copy := *src
+	copy.EligibleNodeGroups = cloneStringSlice(src.EligibleNodeGroups)
+	return &copy
+}
+
+func cloneNodeHealthSnapshot(src *NodeHealthSnapshot) *NodeHealthSnapshot {
+	if src == nil {
+		return nil
+	}
+	copy := *src
+	return &copy
+}
+
+func cloneSchedulerDecision(src *SchedulerDecision) *SchedulerDecision {
+	if src == nil {
+		return nil
+	}
+	copy := *src
+	return &copy
+}
+
+func (s *memoryStore) UpsertTrafficStatCheckpoint(ctx context.Context, checkpoint *TrafficStatCheckpoint) error {
+	_ = ctx
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	copy := cloneCheckpoint(checkpoint)
+	if copy == nil {
+		return errors.New("checkpoint is required")
+	}
+	now := time.Now().UTC()
+	if copy.CreatedAt.IsZero() {
+		copy.CreatedAt = now
+	}
+	copy.UpdatedAt = now
+	s.trafficStatCheckpoints[checkpointKey(copy.NodeID, copy.AccountUUID)] = copy
+	return nil
+}
+
+func (s *memoryStore) GetTrafficStatCheckpoint(ctx context.Context, nodeID, accountUUID string) (*TrafficStatCheckpoint, error) {
+	_ = ctx
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	record, ok := s.trafficStatCheckpoints[checkpointKey(nodeID, accountUUID)]
+	if !ok {
+		return nil, ErrUserNotFound
+	}
+	return cloneCheckpoint(record), nil
+}
+
+func (s *memoryStore) ListTrafficStatCheckpoints(ctx context.Context) ([]TrafficStatCheckpoint, error) {
+	_ = ctx
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	result := make([]TrafficStatCheckpoint, 0, len(s.trafficStatCheckpoints))
+	for _, record := range s.trafficStatCheckpoints {
+		result = append(result, *cloneCheckpoint(record))
+	}
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].NodeID == result[j].NodeID {
+			return result[i].AccountUUID < result[j].AccountUUID
+		}
+		return result[i].NodeID < result[j].NodeID
+	})
+	return result, nil
+}
+
+func (s *memoryStore) UpsertTrafficMinuteBucket(ctx context.Context, bucket *TrafficMinuteBucket) error {
+	_ = ctx
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	copy := cloneBucket(bucket)
+	if copy == nil {
+		return errors.New("bucket is required")
+	}
+	now := time.Now().UTC()
+	if copy.CreatedAt.IsZero() {
+		copy.CreatedAt = now
+	}
+	copy.UpdatedAt = now
+	if strings.TrimSpace(copy.RatingStatus) == "" {
+		copy.RatingStatus = RatingStatusPending
+	}
+	s.trafficMinuteBuckets[bucketKey(copy.BucketStart, copy.NodeID, copy.AccountUUID, copy.Region, copy.LineCode)] = copy
+	return nil
+}
+
+func (s *memoryStore) ListTrafficMinuteBucketsByAccount(ctx context.Context, accountUUID string, start, end time.Time) ([]TrafficMinuteBucket, error) {
+	_ = ctx
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	result := make([]TrafficMinuteBucket, 0)
+	for _, bucket := range s.trafficMinuteBuckets {
+		if bucket.AccountUUID != strings.TrimSpace(accountUUID) {
+			continue
+		}
+		if !start.IsZero() && bucket.BucketStart.Before(start) {
+			continue
+		}
+		if !end.IsZero() && bucket.BucketStart.After(end) {
+			continue
+		}
+		result = append(result, *cloneBucket(bucket))
+	}
+	sort.Slice(result, func(i, j int) bool {
+		return result[i].BucketStart.Before(result[j].BucketStart)
+	})
+	return result, nil
+}
+
+func (s *memoryStore) ListTrafficMinuteBuckets(ctx context.Context) ([]TrafficMinuteBucket, error) {
+	_ = ctx
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	result := make([]TrafficMinuteBucket, 0, len(s.trafficMinuteBuckets))
+	for _, bucket := range s.trafficMinuteBuckets {
+		result = append(result, *cloneBucket(bucket))
+	}
+	sort.Slice(result, func(i, j int) bool {
+		return result[i].BucketStart.Before(result[j].BucketStart)
+	})
+	return result, nil
+}
+
+func (s *memoryStore) InsertBillingLedgerEntry(ctx context.Context, entry *BillingLedgerEntry) error {
+	_ = ctx
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	copy := cloneLedgerEntry(entry)
+	if copy == nil {
+		return errors.New("ledger entry is required")
+	}
+	now := time.Now().UTC()
+	if strings.TrimSpace(copy.ID) == "" {
+		copy.ID = uuid.NewString()
+	}
+	if copy.CreatedAt.IsZero() {
+		copy.CreatedAt = now
+	}
+	s.billingLedgerEntries[copy.ID] = copy
+	entry.ID = copy.ID
+	entry.CreatedAt = copy.CreatedAt
+	return nil
+}
+
+func (s *memoryStore) ListBillingLedgerByAccount(ctx context.Context, accountUUID string, limit int) ([]BillingLedgerEntry, error) {
+	_ = ctx
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	result := make([]BillingLedgerEntry, 0)
+	for _, entry := range s.billingLedgerEntries {
+		if entry.AccountUUID == strings.TrimSpace(accountUUID) {
+			result = append(result, *cloneLedgerEntry(entry))
+		}
+	}
+	sort.Slice(result, func(i, j int) bool {
+		return result[i].CreatedAt.After(result[j].CreatedAt)
+	})
+	if limit > 0 && len(result) > limit {
+		result = result[:limit]
+	}
+	return result, nil
+}
+
+func (s *memoryStore) UpsertAccountQuotaState(ctx context.Context, state *AccountQuotaState) error {
+	_ = ctx
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	copy := cloneQuotaState(state)
+	if copy == nil {
+		return errors.New("quota state is required")
+	}
+	copy.UpdatedAt = time.Now().UTC()
+	if copy.EffectiveAt.IsZero() {
+		copy.EffectiveAt = copy.UpdatedAt
+	}
+	s.accountQuotaStates[strings.TrimSpace(copy.AccountUUID)] = copy
+	return nil
+}
+
+func (s *memoryStore) GetAccountQuotaState(ctx context.Context, accountUUID string) (*AccountQuotaState, error) {
+	_ = ctx
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	record, ok := s.accountQuotaStates[strings.TrimSpace(accountUUID)]
+	if !ok {
+		return nil, ErrUserNotFound
+	}
+	return cloneQuotaState(record), nil
+}
+
+func (s *memoryStore) UpsertAccountPolicySnapshot(ctx context.Context, snapshot *AccountPolicySnapshot) error {
+	_ = ctx
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	copy := clonePolicySnapshot(snapshot)
+	if copy == nil {
+		return errors.New("policy snapshot is required")
+	}
+	now := time.Now().UTC()
+	if copy.CreatedAt.IsZero() {
+		copy.CreatedAt = now
+	}
+	copy.UpdatedAt = now
+	s.accountPolicySnapshots[strings.TrimSpace(copy.AccountUUID)] = copy
+	return nil
+}
+
+func (s *memoryStore) GetLatestAccountPolicySnapshot(ctx context.Context, accountUUID string) (*AccountPolicySnapshot, error) {
+	_ = ctx
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	record, ok := s.accountPolicySnapshots[strings.TrimSpace(accountUUID)]
+	if !ok {
+		return nil, ErrUserNotFound
+	}
+	return clonePolicySnapshot(record), nil
+}
+
+func (s *memoryStore) UpsertNodeHealthSnapshot(ctx context.Context, snapshot *NodeHealthSnapshot) error {
+	_ = ctx
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	copy := cloneNodeHealthSnapshot(snapshot)
+	if copy == nil {
+		return errors.New("node health snapshot is required")
+	}
+	now := time.Now().UTC()
+	if copy.CreatedAt.IsZero() {
+		copy.CreatedAt = now
+	}
+	copy.UpdatedAt = now
+	if copy.SampledAt.IsZero() {
+		copy.SampledAt = now
+	}
+	s.nodeHealthSnapshots[strings.TrimSpace(copy.NodeID)] = copy
+	return nil
+}
+
+func (s *memoryStore) ListLatestNodeHealthSnapshots(ctx context.Context) ([]NodeHealthSnapshot, error) {
+	_ = ctx
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	result := make([]NodeHealthSnapshot, 0, len(s.nodeHealthSnapshots))
+	for _, snapshot := range s.nodeHealthSnapshots {
+		result = append(result, *cloneNodeHealthSnapshot(snapshot))
+	}
+	sort.Slice(result, func(i, j int) bool {
+		return result[i].NodeID < result[j].NodeID
+	})
+	return result, nil
+}
+
+func (s *memoryStore) InsertSchedulerDecision(ctx context.Context, decision *SchedulerDecision) error {
+	_ = ctx
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	copy := cloneSchedulerDecision(decision)
+	if copy == nil {
+		return errors.New("scheduler decision is required")
+	}
+	now := time.Now().UTC()
+	if strings.TrimSpace(copy.ID) == "" {
+		copy.ID = uuid.NewString()
+	}
+	if copy.GeneratedAt.IsZero() {
+		copy.GeneratedAt = now
+	}
+	if copy.CreatedAt.IsZero() {
+		copy.CreatedAt = now
+	}
+	s.schedulerDecisions[copy.ID] = copy
+	decision.ID = copy.ID
+	decision.GeneratedAt = copy.GeneratedAt
+	decision.CreatedAt = copy.CreatedAt
+	return nil
+}
+
+func (s *memoryStore) ListRecentSchedulerDecisions(ctx context.Context, limit int) ([]SchedulerDecision, error) {
+	_ = ctx
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	result := make([]SchedulerDecision, 0, len(s.schedulerDecisions))
+	for _, decision := range s.schedulerDecisions {
+		result = append(result, *cloneSchedulerDecision(decision))
+	}
+	sort.Slice(result, func(i, j int) bool {
+		return result[i].GeneratedAt.After(result[j].GeneratedAt)
+	})
+	if limit > 0 && len(result) > limit {
+		result = result[:limit]
+	}
+	return result, nil
+}
diff --git a/internal/store/accounting_postgres.go b/internal/store/accounting_postgres.go
new file mode 100644
index 0000000..5f9413b
--- /dev/null
+++ b/internal/store/accounting_postgres.go
@@ -0,0 +1,563 @@
+package store
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/google/uuid"
+)
+
+func (s *postgresStore) UpsertTrafficStatCheckpoint(ctx context.Context, checkpoint *TrafficStatCheckpoint) error {
+	if checkpoint == nil {
+		return errors.New("checkpoint is required")
+	}
+
+	const query = `
+		INSERT INTO traffic_stat_checkpoints (
+			node_id, account_uuid, last_uplink_total, last_downlink_total, last_seen_at, xray_revision, reset_epoch
+		) VALUES ($1, $2, $3, $4, $5, $6, $7)
+		ON CONFLICT (node_id, account_uuid) DO UPDATE SET
+			last_uplink_total = EXCLUDED.last_uplink_total,
+			last_downlink_total = EXCLUDED.last_downlink_total,
+			last_seen_at = EXCLUDED.last_seen_at,
+			xray_revision = EXCLUDED.xray_revision,
+			reset_epoch = EXCLUDED.reset_epoch,
+			updated_at = now()
+		RETURNING created_at, updated_at`
+
+	return s.db.QueryRowContext(
+		ctx,
+		query,
+		strings.TrimSpace(checkpoint.NodeID),
+		strings.TrimSpace(checkpoint.AccountUUID),
+		checkpoint.LastUplinkTotal,
+		checkpoint.LastDownlinkTotal,
+		checkpoint.LastSeenAt.UTC(),
+		strings.TrimSpace(checkpoint.XrayRevision),
+		checkpoint.ResetEpoch,
+	).Scan(&checkpoint.CreatedAt, &checkpoint.UpdatedAt)
+}
+
+func (s *postgresStore) GetTrafficStatCheckpoint(ctx context.Context, nodeID, accountUUID string) (*TrafficStatCheckpoint, error) {
+	const query = `
+		SELECT node_id, account_uuid, last_uplink_total, last_downlink_total, last_seen_at, xray_revision, reset_epoch, created_at, updated_at
+		FROM traffic_stat_checkpoints
+		WHERE node_id = $1 AND account_uuid = $2`
+	var record TrafficStatCheckpoint
+	err := s.db.QueryRowContext(ctx, query, strings.TrimSpace(nodeID), strings.TrimSpace(accountUUID)).Scan(
+		&record.NodeID,
+		&record.AccountUUID,
+		&record.LastUplinkTotal,
+		&record.LastDownlinkTotal,
+		&record.LastSeenAt,
+		&record.XrayRevision,
+		&record.ResetEpoch,
+		&record.CreatedAt,
+		&record.UpdatedAt,
+	)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, ErrUserNotFound
+		}
+		return nil, err
+	}
+	return &record, nil
+}
+
+func (s *postgresStore) ListTrafficStatCheckpoints(ctx context.Context) ([]TrafficStatCheckpoint, error) {
+	const query = `
+		SELECT node_id, account_uuid, last_uplink_total, last_downlink_total, last_seen_at, xray_revision, reset_epoch, created_at, updated_at
+		FROM traffic_stat_checkpoints
+		ORDER BY node_id ASC, account_uuid ASC`
+	rows, err := s.db.QueryContext(ctx, query)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var result []TrafficStatCheckpoint
+	for rows.Next() {
+		var record TrafficStatCheckpoint
+		if err := rows.Scan(
+			&record.NodeID,
+			&record.AccountUUID,
+			&record.LastUplinkTotal,
+			&record.LastDownlinkTotal,
+			&record.LastSeenAt,
+			&record.XrayRevision,
+			&record.ResetEpoch,
+			&record.CreatedAt,
+			&record.UpdatedAt,
+		); err != nil {
+			return nil, err
+		}
+		result = append(result, record)
+	}
+	return result, rows.Err()
+}
+
+func (s *postgresStore) UpsertTrafficMinuteBucket(ctx context.Context, bucket *TrafficMinuteBucket) error {
+	if bucket == nil {
+		return errors.New("bucket is required")
+	}
+
+	status := strings.TrimSpace(bucket.RatingStatus)
+	if status == "" {
+		status = RatingStatusPending
+	}
+
+	const query = `
+		INSERT INTO traffic_minute_buckets (
+			bucket_start, node_id, account_uuid, region, line_code, uplink_bytes, downlink_bytes, total_bytes, multiplier, rating_status, source_revision
+		) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11)
+		ON CONFLICT (bucket_start, node_id, account_uuid, region, line_code) DO UPDATE SET
+			uplink_bytes = EXCLUDED.uplink_bytes,
+			downlink_bytes = EXCLUDED.downlink_bytes,
+			total_bytes = EXCLUDED.total_bytes,
+			multiplier = EXCLUDED.multiplier,
+			rating_status = EXCLUDED.rating_status,
+			source_revision = EXCLUDED.source_revision,
+			updated_at = now()
+		RETURNING created_at, updated_at`
+
+	return s.db.QueryRowContext(
+		ctx,
+		query,
+		bucket.BucketStart.UTC(),
+		strings.TrimSpace(bucket.NodeID),
+		strings.TrimSpace(bucket.AccountUUID),
+		strings.TrimSpace(bucket.Region),
+		strings.TrimSpace(bucket.LineCode),
+		bucket.UplinkBytes,
+		bucket.DownlinkBytes,
+		bucket.TotalBytes,
+		bucket.Multiplier,
+		status,
+		strings.TrimSpace(bucket.SourceRevision),
+	).Scan(&bucket.CreatedAt, &bucket.UpdatedAt)
+}
+
+func (s *postgresStore) ListTrafficMinuteBucketsByAccount(ctx context.Context, accountUUID string, start, end time.Time) ([]TrafficMinuteBucket, error) {
+	query := `
+		SELECT bucket_start, node_id, account_uuid, region, line_code, uplink_bytes, downlink_bytes, total_bytes, multiplier, rating_status, source_revision, created_at, updated_at
+		FROM traffic_minute_buckets
+		WHERE account_uuid = $1`
+	args := []any{strings.TrimSpace(accountUUID)}
+	if !start.IsZero() {
+		query += " AND bucket_start >= $2"
+		args = append(args, start.UTC())
+	}
+	if !end.IsZero() {
+		query += " AND bucket_start <= $" + strconv.Itoa(len(args)+1)
+		args = append(args, end.UTC())
+	}
+	query += " ORDER BY bucket_start ASC"
+
+	rows, err := s.db.QueryContext(ctx, query, args...)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var result []TrafficMinuteBucket
+	for rows.Next() {
+		var record TrafficMinuteBucket
+		if err := rows.Scan(
+			&record.BucketStart,
+			&record.NodeID,
+			&record.AccountUUID,
+			&record.Region,
+			&record.LineCode,
+			&record.UplinkBytes,
+			&record.DownlinkBytes,
+			&record.TotalBytes,
+			&record.Multiplier,
+			&record.RatingStatus,
+			&record.SourceRevision,
+			&record.CreatedAt,
+			&record.UpdatedAt,
+		); err != nil {
+			return nil, err
+		}
+		result = append(result, record)
+	}
+	return result, rows.Err()
+}
+
+func (s *postgresStore) ListTrafficMinuteBuckets(ctx context.Context) ([]TrafficMinuteBucket, error) {
+	const query = `
+		SELECT bucket_start, node_id, account_uuid, region, line_code, uplink_bytes, downlink_bytes, total_bytes, multiplier, rating_status, source_revision, created_at, updated_at
+		FROM traffic_minute_buckets
+		ORDER BY bucket_start ASC`
+	rows, err := s.db.QueryContext(ctx, query)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var result []TrafficMinuteBucket
+	for rows.Next() {
+		var record TrafficMinuteBucket
+		if err := rows.Scan(
+			&record.BucketStart,
+			&record.NodeID,
+			&record.AccountUUID,
+			&record.Region,
+			&record.LineCode,
+			&record.UplinkBytes,
+			&record.DownlinkBytes,
+			&record.TotalBytes,
+			&record.Multiplier,
+			&record.RatingStatus,
+			&record.SourceRevision,
+			&record.CreatedAt,
+			&record.UpdatedAt,
+		); err != nil {
+			return nil, err
+		}
+		result = append(result, record)
+	}
+	return result, rows.Err()
+}
+
+func (s *postgresStore) InsertBillingLedgerEntry(ctx context.Context, entry *BillingLedgerEntry) error {
+	if entry == nil {
+		return errors.New("ledger entry is required")
+	}
+	if strings.TrimSpace(entry.ID) == "" {
+		entry.ID = uuid.NewString()
+	}
+
+	const query = `
+		INSERT INTO billing_ledger (
+			id, account_uuid, bucket_start, bucket_end, entry_type, rated_bytes, amount_delta, balance_after, pricing_rule_version
+		) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9)
+		RETURNING created_at`
+
+	return s.db.QueryRowContext(
+		ctx,
+		query,
+		entry.ID,
+		strings.TrimSpace(entry.AccountUUID),
+		entry.BucketStart.UTC(),
+		entry.BucketEnd.UTC(),
+		strings.TrimSpace(entry.EntryType),
+		entry.RatedBytes,
+		entry.AmountDelta,
+		entry.BalanceAfter,
+		strings.TrimSpace(entry.PricingRuleVersion),
+	).Scan(&entry.CreatedAt)
+}
+
+func (s *postgresStore) ListBillingLedgerByAccount(ctx context.Context, accountUUID string, limit int) ([]BillingLedgerEntry, error) {
+	query := `
+		SELECT id, account_uuid, bucket_start, bucket_end, entry_type, rated_bytes, amount_delta, balance_after, pricing_rule_version, created_at
+		FROM billing_ledger
+		WHERE account_uuid = $1
+		ORDER BY created_at DESC`
+	args := []any{strings.TrimSpace(accountUUID)}
+	if limit > 0 {
+		query += " LIMIT $2"
+		args = append(args, limit)
+	}
+	rows, err := s.db.QueryContext(ctx, query, args...)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var result []BillingLedgerEntry
+	for rows.Next() {
+		var entry BillingLedgerEntry
+		if err := rows.Scan(
+			&entry.ID,
+			&entry.AccountUUID,
+			&entry.BucketStart,
+			&entry.BucketEnd,
+			&entry.EntryType,
+			&entry.RatedBytes,
+			&entry.AmountDelta,
+			&entry.BalanceAfter,
+			&entry.PricingRuleVersion,
+			&entry.CreatedAt,
+		); err != nil {
+			return nil, err
+		}
+		result = append(result, entry)
+	}
+	return result, rows.Err()
+}
+
+func (s *postgresStore) UpsertAccountQuotaState(ctx context.Context, state *AccountQuotaState) error {
+	if state == nil {
+		return errors.New("quota state is required")
+	}
+
+	const query = `
+		INSERT INTO account_quota_states (
+			account_uuid, remaining_included_quota, current_balance, arrears, throttle_state, suspend_state, last_rated_bucket_at, effective_at
+		) VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
+		ON CONFLICT (account_uuid) DO UPDATE SET
+			remaining_included_quota = EXCLUDED.remaining_included_quota,
+			current_balance = EXCLUDED.current_balance,
+			arrears = EXCLUDED.arrears,
+			throttle_state = EXCLUDED.throttle_state,
+			suspend_state = EXCLUDED.suspend_state,
+			last_rated_bucket_at = EXCLUDED.last_rated_bucket_at,
+			effective_at = EXCLUDED.effective_at,
+			updated_at = now()
+		RETURNING updated_at`
+
+	return s.db.QueryRowContext(
+		ctx,
+		query,
+		strings.TrimSpace(state.AccountUUID),
+		state.RemainingIncludedQuota,
+		state.CurrentBalance,
+		state.Arrears,
+		strings.TrimSpace(state.ThrottleState),
+		strings.TrimSpace(state.SuspendState),
+		state.LastRatedBucketAt,
+		state.EffectiveAt.UTC(),
+	).Scan(&state.UpdatedAt)
+}
+
+func (s *postgresStore) GetAccountQuotaState(ctx context.Context, accountUUID string) (*AccountQuotaState, error) {
+	const query = `
+		SELECT account_uuid, remaining_included_quota, current_balance, arrears, throttle_state, suspend_state, last_rated_bucket_at, effective_at, updated_at
+		FROM account_quota_states
+		WHERE account_uuid = $1`
+	var state AccountQuotaState
+	err := s.db.QueryRowContext(ctx, query, strings.TrimSpace(accountUUID)).Scan(
+		&state.AccountUUID,
+		&state.RemainingIncludedQuota,
+		&state.CurrentBalance,
+		&state.Arrears,
+		&state.ThrottleState,
+		&state.SuspendState,
+		&state.LastRatedBucketAt,
+		&state.EffectiveAt,
+		&state.UpdatedAt,
+	)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, ErrUserNotFound
+		}
+		return nil, err
+	}
+	return &state, nil
+}
+
+func (s *postgresStore) UpsertAccountPolicySnapshot(ctx context.Context, snapshot *AccountPolicySnapshot) error {
+	if snapshot == nil {
+		return errors.New("policy snapshot is required")
+	}
+
+	groups, err := encodeStringSlice(snapshot.EligibleNodeGroups)
+	if err != nil {
+		return err
+	}
+
+	const query = `
+		INSERT INTO account_policy_snapshots (
+			account_uuid, policy_version, auth_state, rate_profile, conn_profile, eligible_node_groups, preferred_strategy, degrade_mode, expires_at
+		) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9)
+		ON CONFLICT (account_uuid) DO UPDATE SET
+			policy_version = EXCLUDED.policy_version,
+			auth_state = EXCLUDED.auth_state,
+			rate_profile = EXCLUDED.rate_profile,
+			conn_profile = EXCLUDED.conn_profile,
+			eligible_node_groups = EXCLUDED.eligible_node_groups,
+			preferred_strategy = EXCLUDED.preferred_strategy,
+			degrade_mode = EXCLUDED.degrade_mode,
+			expires_at = EXCLUDED.expires_at,
+			updated_at = now()
+		RETURNING created_at, updated_at`
+
+	return s.db.QueryRowContext(
+		ctx,
+		query,
+		strings.TrimSpace(snapshot.AccountUUID),
+		strings.TrimSpace(snapshot.PolicyVersion),
+		strings.TrimSpace(snapshot.AuthState),
+		strings.TrimSpace(snapshot.RateProfile),
+		strings.TrimSpace(snapshot.ConnProfile),
+		groups,
+		strings.TrimSpace(snapshot.PreferredStrategy),
+		strings.TrimSpace(snapshot.DegradeMode),
+		snapshot.ExpiresAt.UTC(),
+	).Scan(&snapshot.CreatedAt, &snapshot.UpdatedAt)
+}
+
+func (s *postgresStore) GetLatestAccountPolicySnapshot(ctx context.Context, accountUUID string) (*AccountPolicySnapshot, error) {
+	const query = `
+		SELECT account_uuid, policy_version, auth_state, rate_profile, conn_profile, eligible_node_groups, preferred_strategy, degrade_mode, expires_at, created_at, updated_at
+		FROM account_policy_snapshots
+		WHERE account_uuid = $1`
+	var snapshot AccountPolicySnapshot
+	var groups []byte
+	err := s.db.QueryRowContext(ctx, query, strings.TrimSpace(accountUUID)).Scan(
+		&snapshot.AccountUUID,
+		&snapshot.PolicyVersion,
+		&snapshot.AuthState,
+		&snapshot.RateProfile,
+		&snapshot.ConnProfile,
+		&groups,
+		&snapshot.PreferredStrategy,
+		&snapshot.DegradeMode,
+		&snapshot.ExpiresAt,
+		&snapshot.CreatedAt,
+		&snapshot.UpdatedAt,
+	)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, ErrUserNotFound
+		}
+		return nil, err
+	}
+	snapshot.EligibleNodeGroups = decodeStringSlice(groups)
+	return &snapshot, nil
+}
+
+func (s *postgresStore) UpsertNodeHealthSnapshot(ctx context.Context, snapshot *NodeHealthSnapshot) error {
+	if snapshot == nil {
+		return errors.New("node health snapshot is required")
+	}
+
+	const query = `
+		INSERT INTO node_health_snapshots (
+			node_id, region, line_code, pricing_group, stats_enabled, xray_revision, healthy, latency_ms, error_rate, active_connections, health_score, sampled_at
+		) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12)
+		ON CONFLICT (node_id) DO UPDATE SET
+			region = EXCLUDED.region,
+			line_code = EXCLUDED.line_code,
+			pricing_group = EXCLUDED.pricing_group,
+			stats_enabled = EXCLUDED.stats_enabled,
+			xray_revision = EXCLUDED.xray_revision,
+			healthy = EXCLUDED.healthy,
+			latency_ms = EXCLUDED.latency_ms,
+			error_rate = EXCLUDED.error_rate,
+			active_connections = EXCLUDED.active_connections,
+			health_score = EXCLUDED.health_score,
+			sampled_at = EXCLUDED.sampled_at,
+			updated_at = now()
+		RETURNING created_at, updated_at`
+
+	return s.db.QueryRowContext(
+		ctx,
+		query,
+		strings.TrimSpace(snapshot.NodeID),
+		strings.TrimSpace(snapshot.Region),
+		strings.TrimSpace(snapshot.LineCode),
+		strings.TrimSpace(snapshot.PricingGroup),
+		snapshot.StatsEnabled,
+		strings.TrimSpace(snapshot.XrayRevision),
+		snapshot.Healthy,
+		snapshot.LatencyMS,
+		snapshot.ErrorRate,
+		snapshot.ActiveConnections,
+		snapshot.HealthScore,
+		snapshot.SampledAt.UTC(),
+	).Scan(&snapshot.CreatedAt, &snapshot.UpdatedAt)
+}
+
+func (s *postgresStore) ListLatestNodeHealthSnapshots(ctx context.Context) ([]NodeHealthSnapshot, error) {
+	const query = `
+		SELECT node_id, region, line_code, pricing_group, stats_enabled, xray_revision, healthy, latency_ms, error_rate, active_connections, health_score, sampled_at, created_at, updated_at
+		FROM node_health_snapshots
+		ORDER BY node_id ASC`
+	rows, err := s.db.QueryContext(ctx, query)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var result []NodeHealthSnapshot
+	for rows.Next() {
+		var snapshot NodeHealthSnapshot
+		if err := rows.Scan(
+			&snapshot.NodeID,
+			&snapshot.Region,
+			&snapshot.LineCode,
+			&snapshot.PricingGroup,
+			&snapshot.StatsEnabled,
+			&snapshot.XrayRevision,
+			&snapshot.Healthy,
+			&snapshot.LatencyMS,
+			&snapshot.ErrorRate,
+			&snapshot.ActiveConnections,
+			&snapshot.HealthScore,
+			&snapshot.SampledAt,
+			&snapshot.CreatedAt,
+			&snapshot.UpdatedAt,
+		); err != nil {
+			return nil, err
+		}
+		result = append(result, snapshot)
+	}
+	return result, rows.Err()
+}
+
+func (s *postgresStore) InsertSchedulerDecision(ctx context.Context, decision *SchedulerDecision) error {
+	if decision == nil {
+		return errors.New("scheduler decision is required")
+	}
+	if strings.TrimSpace(decision.ID) == "" {
+		decision.ID = uuid.NewString()
+	}
+
+	const query = `
+		INSERT INTO scheduler_decisions (id, account_uuid, node_group, strategy, decision, generated_at)
+		VALUES ($1, $2, $3, $4, $5, $6)
+		RETURNING created_at`
+
+	return s.db.QueryRowContext(
+		ctx,
+		query,
+		decision.ID,
+		strings.TrimSpace(decision.AccountUUID),
+		strings.TrimSpace(decision.NodeGroup),
+		strings.TrimSpace(decision.Strategy),
+		strings.TrimSpace(decision.Decision),
+		decision.GeneratedAt.UTC(),
+	).Scan(&decision.CreatedAt)
+}
+
+func (s *postgresStore) ListRecentSchedulerDecisions(ctx context.Context, limit int) ([]SchedulerDecision, error) {
+	query := `
+		SELECT id, account_uuid, node_group, strategy, decision, generated_at, created_at
+		FROM scheduler_decisions
+		ORDER BY generated_at DESC`
+	args := []any{}
+	if limit > 0 {
+		query += " LIMIT $1"
+		args = append(args, limit)
+	}
+	rows, err := s.db.QueryContext(ctx, query, args...)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var result []SchedulerDecision
+	for rows.Next() {
+		var decision SchedulerDecision
+		if err := rows.Scan(
+			&decision.ID,
+			&decision.AccountUUID,
+			&decision.NodeGroup,
+			&decision.Strategy,
+			&decision.Decision,
+			&decision.GeneratedAt,
+			&decision.CreatedAt,
+		); err != nil {
+			return nil, err
+		}
+		result = append(result, decision)
+	}
+	return result, rows.Err()
+}
diff --git a/internal/store/store.go b/internal/store/store.go
index 9b3d44b..ce3312f 100644
--- a/internal/store/store.go
+++ b/internal/store/store.go
@@ -73,6 +73,105 @@ type Agent struct {
 	UpdatedAt     time.Time  `json:"updatedAt"`
 }
 
+const (
+	RatingStatusPending = "pending"
+	RatingStatusRated   = "rated"
+)
+
+type TrafficStatCheckpoint struct {
+	NodeID            string
+	AccountUUID       string
+	LastUplinkTotal   int64
+	LastDownlinkTotal int64
+	LastSeenAt        time.Time
+	XrayRevision      string
+	ResetEpoch        int64
+	CreatedAt         time.Time
+	UpdatedAt         time.Time
+}
+
+type TrafficMinuteBucket struct {
+	BucketStart    time.Time
+	NodeID         string
+	AccountUUID    string
+	Region         string
+	LineCode       string
+	UplinkBytes    int64
+	DownlinkBytes  int64
+	TotalBytes     int64
+	Multiplier     float64
+	RatingStatus   string
+	SourceRevision string
+	CreatedAt      time.Time
+	UpdatedAt      time.Time
+}
+
+type BillingLedgerEntry struct {
+	ID                 string
+	AccountUUID        string
+	BucketStart        time.Time
+	BucketEnd          time.Time
+	EntryType          string
+	RatedBytes         int64
+	AmountDelta        float64
+	BalanceAfter       float64
+	PricingRuleVersion string
+	CreatedAt          time.Time
+}
+
+type AccountQuotaState struct {
+	AccountUUID            string
+	RemainingIncludedQuota int64
+	CurrentBalance         float64
+	Arrears                bool
+	ThrottleState          string
+	SuspendState           string
+	LastRatedBucketAt      *time.Time
+	EffectiveAt            time.Time
+	UpdatedAt              time.Time
+}
+
+type AccountPolicySnapshot struct {
+	AccountUUID        string
+	PolicyVersion      string
+	AuthState          string
+	RateProfile        string
+	ConnProfile        string
+	EligibleNodeGroups []string
+	PreferredStrategy  string
+	DegradeMode        string
+	ExpiresAt          time.Time
+	CreatedAt          time.Time
+	UpdatedAt          time.Time
+}
+
+type NodeHealthSnapshot struct {
+	NodeID            string
+	Region            string
+	LineCode          string
+	PricingGroup      string
+	StatsEnabled      bool
+	XrayRevision      string
+	Healthy           bool
+	LatencyMS         int
+	ErrorRate         float64
+	ActiveConnections int
+	HealthScore       float64
+	SampledAt         time.Time
+	CreatedAt         time.Time
+	UpdatedAt         time.Time
+}
+
+type SchedulerDecision struct {
+	ID          string
+	AccountUUID string
+	NodeGroup   string
+	Strategy    string
+	Decision    string
+	GeneratedAt time.Time
+	CreatedAt   time.Time
+}
+
 // Store provides persistence operations for users.
 type Store interface {
 	CreateUser(ctx context.Context, user *User) error
@@ -106,6 +205,23 @@ type Store interface {
 	DeleteAgent(ctx context.Context, id string) error
 	DeleteStaleAgents(ctx context.Context, staleThreshold time.Duration) (int, error)
 
+	UpsertTrafficStatCheckpoint(ctx context.Context, checkpoint *TrafficStatCheckpoint) error
+	GetTrafficStatCheckpoint(ctx context.Context, nodeID, accountUUID string) (*TrafficStatCheckpoint, error)
+	ListTrafficStatCheckpoints(ctx context.Context) ([]TrafficStatCheckpoint, error)
+	UpsertTrafficMinuteBucket(ctx context.Context, bucket *TrafficMinuteBucket) error
+	ListTrafficMinuteBucketsByAccount(ctx context.Context, accountUUID string, start, end time.Time) ([]TrafficMinuteBucket, error)
+	ListTrafficMinuteBuckets(ctx context.Context) ([]TrafficMinuteBucket, error)
+	InsertBillingLedgerEntry(ctx context.Context, entry *BillingLedgerEntry) error
+	ListBillingLedgerByAccount(ctx context.Context, accountUUID string, limit int) ([]BillingLedgerEntry, error)
+	UpsertAccountQuotaState(ctx context.Context, state *AccountQuotaState) error
+	GetAccountQuotaState(ctx context.Context, accountUUID string) (*AccountQuotaState, error)
+	UpsertAccountPolicySnapshot(ctx context.Context, snapshot *AccountPolicySnapshot) error
+	GetLatestAccountPolicySnapshot(ctx context.Context, accountUUID string) (*AccountPolicySnapshot, error)
+	UpsertNodeHealthSnapshot(ctx context.Context, snapshot *NodeHealthSnapshot) error
+	ListLatestNodeHealthSnapshots(ctx context.Context) ([]NodeHealthSnapshot, error)
+	InsertSchedulerDecision(ctx context.Context, decision *SchedulerDecision) error
+	ListRecentSchedulerDecisions(ctx context.Context, limit int) ([]SchedulerDecision, error)
+
 	EnsureTenant(ctx context.Context, tenant *Tenant) error
 	EnsureTenantDomain(ctx context.Context, domain *TenantDomain) error
 	UpsertTenantMembership(ctx context.Context, membership *TenantMembership) error
@@ -144,6 +260,13 @@ type memoryStore struct {
 	tenantDomains           map[string]*TenantDomain
 	tenantMemberships       map[string]map[string]*TenantMembership
 	xworkmateProfiles       map[string]*XWorkmateProfile
+	trafficStatCheckpoints  map[string]*TrafficStatCheckpoint
+	trafficMinuteBuckets    map[string]*TrafficMinuteBucket
+	billingLedgerEntries    map[string]*BillingLedgerEntry
+	accountQuotaStates      map[string]*AccountQuotaState
+	accountPolicySnapshots  map[string]*AccountPolicySnapshot
+	nodeHealthSnapshots     map[string]*NodeHealthSnapshot
+	schedulerDecisions      map[string]*SchedulerDecision
 }
 
 type sessionRecord struct {
@@ -182,6 +305,13 @@ func newMemoryStore(allowSuperAdminCounting bool) Store {
 		tenantDomains:           make(map[string]*TenantDomain),
 		tenantMemberships:       make(map[string]map[string]*TenantMembership),
 		xworkmateProfiles:       make(map[string]*XWorkmateProfile),
+		trafficStatCheckpoints:  make(map[string]*TrafficStatCheckpoint),
+		trafficMinuteBuckets:    make(map[string]*TrafficMinuteBucket),
+		billingLedgerEntries:    make(map[string]*BillingLedgerEntry),
+		accountQuotaStates:      make(map[string]*AccountQuotaState),
+		accountPolicySnapshots:  make(map[string]*AccountPolicySnapshot),
+		nodeHealthSnapshots:     make(map[string]*NodeHealthSnapshot),
+		schedulerDecisions:      make(map[string]*SchedulerDecision),
 	}
 }
 
diff --git a/sql/20260401_accounting_control_plane.sql b/sql/20260401_accounting_control_plane.sql
new file mode 100644
index 0000000..73c835e
--- /dev/null
+++ b/sql/20260401_accounting_control_plane.sql
@@ -0,0 +1,107 @@
+CREATE TABLE IF NOT EXISTS public.traffic_stat_checkpoints (
+  node_id TEXT NOT NULL,
+  account_uuid UUID NOT NULL REFERENCES public.users(uuid) ON DELETE CASCADE,
+  last_uplink_total BIGINT NOT NULL DEFAULT 0,
+  last_downlink_total BIGINT NOT NULL DEFAULT 0,
+  last_seen_at TIMESTAMPTZ NOT NULL,
+  xray_revision TEXT NOT NULL DEFAULT '',
+  reset_epoch BIGINT NOT NULL DEFAULT 0,
+  created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+  updated_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+  PRIMARY KEY (node_id, account_uuid)
+);
+
+CREATE TABLE IF NOT EXISTS public.traffic_minute_buckets (
+  bucket_start TIMESTAMPTZ NOT NULL,
+  node_id TEXT NOT NULL,
+  account_uuid UUID NOT NULL REFERENCES public.users(uuid) ON DELETE CASCADE,
+  region TEXT NOT NULL DEFAULT '',
+  line_code TEXT NOT NULL DEFAULT '',
+  uplink_bytes BIGINT NOT NULL DEFAULT 0,
+  downlink_bytes BIGINT NOT NULL DEFAULT 0,
+  total_bytes BIGINT NOT NULL DEFAULT 0,
+  multiplier DOUBLE PRECISION NOT NULL DEFAULT 1.0,
+  rating_status TEXT NOT NULL DEFAULT 'pending',
+  source_revision TEXT NOT NULL DEFAULT '',
+  created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+  updated_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+  PRIMARY KEY (bucket_start, node_id, account_uuid, region, line_code)
+);
+
+CREATE TABLE IF NOT EXISTS public.billing_ledger (
+  id UUID PRIMARY KEY,
+  account_uuid UUID NOT NULL REFERENCES public.users(uuid) ON DELETE CASCADE,
+  bucket_start TIMESTAMPTZ NOT NULL,
+  bucket_end TIMESTAMPTZ NOT NULL,
+  entry_type TEXT NOT NULL,
+  rated_bytes BIGINT NOT NULL DEFAULT 0,
+  amount_delta DOUBLE PRECISION NOT NULL DEFAULT 0,
+  balance_after DOUBLE PRECISION NOT NULL DEFAULT 0,
+  pricing_rule_version TEXT NOT NULL DEFAULT '',
+  created_at TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+CREATE TABLE IF NOT EXISTS public.account_quota_states (
+  account_uuid UUID PRIMARY KEY REFERENCES public.users(uuid) ON DELETE CASCADE,
+  remaining_included_quota BIGINT NOT NULL DEFAULT 0,
+  current_balance DOUBLE PRECISION NOT NULL DEFAULT 0,
+  arrears BOOLEAN NOT NULL DEFAULT false,
+  throttle_state TEXT NOT NULL DEFAULT 'normal',
+  suspend_state TEXT NOT NULL DEFAULT 'active',
+  last_rated_bucket_at TIMESTAMPTZ NULL,
+  effective_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+  updated_at TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+CREATE TABLE IF NOT EXISTS public.account_policy_snapshots (
+  account_uuid UUID PRIMARY KEY REFERENCES public.users(uuid) ON DELETE CASCADE,
+  policy_version TEXT NOT NULL,
+  auth_state TEXT NOT NULL DEFAULT 'active',
+  rate_profile TEXT NOT NULL DEFAULT 'standard',
+  conn_profile TEXT NOT NULL DEFAULT 'standard',
+  eligible_node_groups JSONB NOT NULL DEFAULT '[]'::jsonb,
+  preferred_strategy TEXT NOT NULL DEFAULT 'ewma',
+  degrade_mode TEXT NOT NULL DEFAULT 'deny',
+  expires_at TIMESTAMPTZ NOT NULL,
+  created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+  updated_at TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+CREATE TABLE IF NOT EXISTS public.node_health_snapshots (
+  node_id TEXT PRIMARY KEY,
+  region TEXT NOT NULL DEFAULT '',
+  line_code TEXT NOT NULL DEFAULT '',
+  pricing_group TEXT NOT NULL DEFAULT '',
+  stats_enabled BOOLEAN NOT NULL DEFAULT false,
+  xray_revision TEXT NOT NULL DEFAULT '',
+  healthy BOOLEAN NOT NULL DEFAULT false,
+  latency_ms INTEGER NOT NULL DEFAULT 0,
+  error_rate DOUBLE PRECISION NOT NULL DEFAULT 0,
+  active_connections INTEGER NOT NULL DEFAULT 0,
+  health_score DOUBLE PRECISION NOT NULL DEFAULT 0,
+  sampled_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+  created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+  updated_at TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+CREATE TABLE IF NOT EXISTS public.scheduler_decisions (
+  id UUID PRIMARY KEY,
+  account_uuid UUID NULL REFERENCES public.users(uuid) ON DELETE CASCADE,
+  node_group TEXT NOT NULL DEFAULT '',
+  strategy TEXT NOT NULL DEFAULT '',
+  decision TEXT NOT NULL DEFAULT '',
+  generated_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+  created_at TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+CREATE INDEX IF NOT EXISTS idx_traffic_minute_buckets_account_bucket
+  ON public.traffic_minute_buckets (account_uuid, bucket_start DESC);
+
+CREATE INDEX IF NOT EXISTS idx_billing_ledger_account_created
+  ON public.billing_ledger (account_uuid, created_at DESC);
+
+CREATE INDEX IF NOT EXISTS idx_node_health_snapshots_sampled
+  ON public.node_health_snapshots (sampled_at DESC);
+
+CREATE INDEX IF NOT EXISTS idx_scheduler_decisions_generated
+  ON public.scheduler_decisions (generated_at DESC);