feat(announcements): add admin/user announcement system

Implements announcements end-to-end (admin CRUD + read status, user list + mark read) with OR-of-AND targeting. Also breaks the ent<->service import cycle by moving schema-facing constants/targeting into a new domain package.

feat(announcements): add admin/user announcement system
Implements announcements end-to-end (admin CRUD + read status, user list + mark read) with OR-of-AND targeting. Also breaks the ent<->service import cycle by moving schema-facing constants/targeting into a new domain package.
b7f69844 · ducky · cadca752 · b7f69844 · b7f69844 · b7f69844
Commit b7f69844 authored Jan 30, 2026 by ducky
--- a/backend/internal/domain/constants.go
+++ b/backend/internal/domain/constants.go
+package domain
+// Status constants
+const (
+	StatusActive   = "active"
+	StatusDisabled = "disabled"
+	StatusError    = "error"
+	StatusUnused   = "unused"
+	StatusUsed     = "used"
+	StatusExpired  = "expired"
+)
+// Role constants
+const (
+	RoleAdmin = "admin"
+	RoleUser  = "user"
+)
+// Platform constants
+const (
+	PlatformAnthropic   = "anthropic"
+	PlatformOpenAI      = "openai"
+	PlatformGemini      = "gemini"
+	PlatformAntigravity = "antigravity"
+)
+// Account type constants
+const (
+	AccountTypeOAuth      = "oauth"       // OAuth类型账号（full scope: profile + inference）
+	AccountTypeSetupToken = "setup-token" // Setup Token类型账号（inference only scope）
+	AccountTypeAPIKey     = "apikey"      // API Key类型账号
+)
+// Redeem type constants
+const (
+	RedeemTypeBalance      = "balance"
+	RedeemTypeConcurrency  = "concurrency"
+	RedeemTypeSubscription = "subscription"
+)
+// PromoCode status constants
+const (
+	PromoCodeStatusActive   = "active"
+	PromoCodeStatusDisabled = "disabled"
+)
+// Admin adjustment type constants
+const (
+	AdjustmentTypeAdminBalance     = "admin_balance"     // 管理员调整余额
+	AdjustmentTypeAdminConcurrency = "admin_concurrency" // 管理员调整并发数
+)
+// Group subscription type constants
+const (
+	SubscriptionTypeStandard     = "standard"     // 标准计费模式（按余额扣费）
+	SubscriptionTypeSubscription = "subscription" // 订阅模式（按限额控制）
+)
+// Subscription status constants
+const (
+	SubscriptionStatusActive    = "active"
+	SubscriptionStatusExpired   = "expired"
+	SubscriptionStatusSuspended = "suspended"
+)
--- a/backend/internal/handler/admin/announcement_handler.go
+++ b/backend/internal/handler/admin/announcement_handler.go
+package admin
+import (
+	"strconv"
+	"strings"
+	"time"
+	"github.com/Wei-Shaw/sub2api/internal/handler/dto"
+	"github.com/Wei-Shaw/sub2api/internal/pkg/pagination"
+	"github.com/Wei-Shaw/sub2api/internal/pkg/response"
+	middleware2 "github.com/Wei-Shaw/sub2api/internal/server/middleware"
+	"github.com/Wei-Shaw/sub2api/internal/service"
+	"github.com/gin-gonic/gin"
+)
+// AnnouncementHandler handles admin announcement management
+type AnnouncementHandler struct {
+	announcementService *service.AnnouncementService
+}
+// NewAnnouncementHandler creates a new admin announcement handler
+func NewAnnouncementHandler(announcementService *service.AnnouncementService) *AnnouncementHandler {
+	return &AnnouncementHandler{
+		announcementService: announcementService,
+	}
+}
+type CreateAnnouncementRequest struct {
+	Title     string                       `json:"title" binding:"required"`
+	Content   string                       `json:"content" binding:"required"`
+	Status    string                       `json:"status" binding:"omitempty,oneof=draft active archived"`
+	Targeting service.AnnouncementTargeting `json:"targeting"`
+	StartsAt  *int64                       `json:"starts_at"` // Unix seconds, 0/empty = immediate
+	EndsAt    *int64                       `json:"ends_at"`   // Unix seconds, 0/empty = never
+}
+type UpdateAnnouncementRequest struct {
+	Title     *string                        `json:"title"`
+	Content   *string                        `json:"content"`
+	Status    *string                        `json:"status" binding:"omitempty,oneof=draft active archived"`
+	Targeting *service.AnnouncementTargeting `json:"targeting"`
+	StartsAt  *int64                         `json:"starts_at"` // Unix seconds, 0 = clear
+	EndsAt    *int64                         `json:"ends_at"`   // Unix seconds, 0 = clear
+}
+// List handles listing announcements with filters
+// GET /api/v1/admin/announcements
+func (h *AnnouncementHandler) List(c *gin.Context) {
+	page, pageSize := response.ParsePagination(c)
+	status := strings.TrimSpace(c.Query("status"))
+	search := strings.TrimSpace(c.Query("search"))
+	if len(search) > 200 {
+		search = search[:200]
+	}
+	params := pagination.PaginationParams{
+		Page:     page,
+		PageSize: pageSize,
+	}
+	items, paginationResult, err := h.announcementService.List(
+		c.Request.Context(),
+		params,
+		service.AnnouncementListFilters{Status: status, Search: search},
+	)
+	if err != nil {
+		response.ErrorFrom(c, err)
+		return
+	}
+	out := make([]dto.Announcement, 0, len(items))
+	for i := range items {
+		out = append(out, *dto.AnnouncementFromService(&items[i]))
+	}
+	response.Paginated(c, out, paginationResult.Total, page, pageSize)
+}
+// GetByID handles getting an announcement by ID
+// GET /api/v1/admin/announcements/:id
+func (h *AnnouncementHandler) GetByID(c *gin.Context) {
+	announcementID, err := strconv.ParseInt(c.Param("id"), 10, 64)
+	if err != nil || announcementID <= 0 {
+		response.BadRequest(c, "Invalid announcement ID")
+		return
+	}
+	item, err := h.announcementService.GetByID(c.Request.Context(), announcementID)
+	if err != nil {
+		response.ErrorFrom(c, err)
+		return
+	}
+	response.Success(c, dto.AnnouncementFromService(item))
+}
+// Create handles creating a new announcement
+// POST /api/v1/admin/announcements
+func (h *AnnouncementHandler) Create(c *gin.Context) {
+	var req CreateAnnouncementRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		response.BadRequest(c, "Invalid request: "+err.Error())
+		return
+	}
+	subject, ok := middleware2.GetAuthSubjectFromContext(c)
+	if !ok {
+		response.Unauthorized(c, "User not found in context")
+		return
+	}
+	input := &service.CreateAnnouncementInput{
+		Title:     req.Title,
+		Content:   req.Content,
+		Status:    req.Status,
+		Targeting: req.Targeting,
+		ActorID:   &subject.UserID,
+	}
+	if req.StartsAt != nil && *req.StartsAt > 0 {
+		t := time.Unix(*req.StartsAt, 0)
+		input.StartsAt = &t
+	}
+	if req.EndsAt != nil && *req.EndsAt > 0 {
+		t := time.Unix(*req.EndsAt, 0)
+		input.EndsAt = &t
+	}
+	created, err := h.announcementService.Create(c.Request.Context(), input)
+	if err != nil {
+		response.ErrorFrom(c, err)
+		return
+	}
+	response.Success(c, dto.AnnouncementFromService(created))
+}
+// Update handles updating an announcement
+// PUT /api/v1/admin/announcements/:id
+func (h *AnnouncementHandler) Update(c *gin.Context) {
+	announcementID, err := strconv.ParseInt(c.Param("id"), 10, 64)
+	if err != nil || announcementID <= 0 {
+		response.BadRequest(c, "Invalid announcement ID")
+		return
+	}
+	var req UpdateAnnouncementRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		response.BadRequest(c, "Invalid request: "+err.Error())
+		return
+	}
+	subject, ok := middleware2.GetAuthSubjectFromContext(c)
+	if !ok {
+		response.Unauthorized(c, "User not found in context")
+		return
+	}
+	input := &service.UpdateAnnouncementInput{
+		Title:     req.Title,
+		Content:   req.Content,
+		Status:    req.Status,
+		Targeting: req.Targeting,
+		ActorID:   &subject.UserID,
+	}
+	if req.StartsAt != nil {
+		if *req.StartsAt == 0 {
+			var cleared *time.Time = nil
+			input.StartsAt = &cleared
+		} else {
+			t := time.Unix(*req.StartsAt, 0)
+			ptr := &t
+			input.StartsAt = &ptr
+		}
+	}
+	if req.EndsAt != nil {
+		if *req.EndsAt == 0 {
+			var cleared *time.Time = nil
+			input.EndsAt = &cleared
+		} else {
+			t := time.Unix(*req.EndsAt, 0)
+			ptr := &t
+			input.EndsAt = &ptr
+		}
+	}
+	updated, err := h.announcementService.Update(c.Request.Context(), announcementID, input)
+	if err != nil {
+		response.ErrorFrom(c, err)
+		return
+	}
+	response.Success(c, dto.AnnouncementFromService(updated))
+}
+// Delete handles deleting an announcement
+// DELETE /api/v1/admin/announcements/:id
+func (h *AnnouncementHandler) Delete(c *gin.Context) {
+	announcementID, err := strconv.ParseInt(c.Param("id"), 10, 64)
+	if err != nil || announcementID <= 0 {
+		response.BadRequest(c, "Invalid announcement ID")
+		return
+	}
+	if err := h.announcementService.Delete(c.Request.Context(), announcementID); err != nil {
+		response.ErrorFrom(c, err)
+		return
+	}
+	response.Success(c, gin.H{"message": "Announcement deleted successfully"})
+}
+// ListReadStatus handles listing users read status for an announcement
+// GET /api/v1/admin/announcements/:id/read-status
+func (h *AnnouncementHandler) ListReadStatus(c *gin.Context) {
+	announcementID, err := strconv.ParseInt(c.Param("id"), 10, 64)
+	if err != nil || announcementID <= 0 {
+		response.BadRequest(c, "Invalid announcement ID")
+		return
+	}
+	page, pageSize := response.ParsePagination(c)
+	params := pagination.PaginationParams{
+		Page:     page,
+		PageSize: pageSize,
+	}
+	search := strings.TrimSpace(c.Query("search"))
+	if len(search) > 200 {
+		search = search[:200]
+	}
+	items, paginationResult, err := h.announcementService.ListUserReadStatus(
+		c.Request.Context(),
+		announcementID,
+		params,
+		search,
+	)
+	if err != nil {
+		response.ErrorFrom(c, err)
+		return
+	}
+	response.Paginated(c, items, paginationResult.Total, page, pageSize)
+}
--- a/backend/internal/handler/announcement_handler.go
+++ b/backend/internal/handler/announcement_handler.go
+package handler
+import (
+	"strconv"
+	"strings"
+	"github.com/Wei-Shaw/sub2api/internal/handler/dto"
+	"github.com/Wei-Shaw/sub2api/internal/pkg/response"
+	middleware2 "github.com/Wei-Shaw/sub2api/internal/server/middleware"
+	"github.com/Wei-Shaw/sub2api/internal/service"
+	"github.com/gin-gonic/gin"
+)
+// AnnouncementHandler handles user announcement operations
+type AnnouncementHandler struct {
+	announcementService *service.AnnouncementService
+}
+// NewAnnouncementHandler creates a new user announcement handler
+func NewAnnouncementHandler(announcementService *service.AnnouncementService) *AnnouncementHandler {
+	return &AnnouncementHandler{
+		announcementService: announcementService,
+	}
+}
+// List handles listing announcements visible to current user
+// GET /api/v1/announcements
+func (h *AnnouncementHandler) List(c *gin.Context) {
+	subject, ok := middleware2.GetAuthSubjectFromContext(c)
+	if !ok {
+		response.Unauthorized(c, "User not found in context")
+		return
+	}
+	unreadOnly := parseBoolQuery(c.Query("unread_only"))
+	items, err := h.announcementService.ListForUser(c.Request.Context(), subject.UserID, unreadOnly)
+	if err != nil {
+		response.ErrorFrom(c, err)
+		return
+	}
+	out := make([]dto.UserAnnouncement, 0, len(items))
+	for i := range items {
+		out = append(out, *dto.UserAnnouncementFromService(&items[i]))
+	}
+	response.Success(c, out)
+}
+// MarkRead marks an announcement as read for current user
+// POST /api/v1/announcements/:id/read
+func (h *AnnouncementHandler) MarkRead(c *gin.Context) {
+	subject, ok := middleware2.GetAuthSubjectFromContext(c)
+	if !ok {
+		response.Unauthorized(c, "User not found in context")
+		return
+	}
+	announcementID, err := strconv.ParseInt(c.Param("id"), 10, 64)
+	if err != nil || announcementID <= 0 {
+		response.BadRequest(c, "Invalid announcement ID")
+		return
+	}
+	if err := h.announcementService.MarkRead(c.Request.Context(), subject.UserID, announcementID); err != nil {
+		response.ErrorFrom(c, err)
+		return
+	}
+	response.Success(c, gin.H{"message": "ok"})
+}
+func parseBoolQuery(v string) bool {
+	switch strings.TrimSpace(strings.ToLower(v)) {
+	case "1", "true", "yes", "y", "on":
+		return true
+	default:
+		return false
+	}
+}
--- a/backend/internal/handler/dto/announcement.go
+++ b/backend/internal/handler/dto/announcement.go
+package dto
+import (
+	"time"
+	"github.com/Wei-Shaw/sub2api/internal/service"
+)
+type Announcement struct {
+	ID      int64  `json:"id"`
+	Title   string `json:"title"`
+	Content string `json:"content"`
+	Status  string `json:"status"`
+	Targeting service.AnnouncementTargeting `json:"targeting"`
+	StartsAt *time.Time `json:"starts_at,omitempty"`
+	EndsAt   *time.Time `json:"ends_at,omitempty"`
+	CreatedBy *int64 `json:"created_by,omitempty"`
+	UpdatedBy *int64 `json:"updated_by,omitempty"`
+	CreatedAt time.Time `json:"created_at"`
+	UpdatedAt time.Time `json:"updated_at"`
+}
+type UserAnnouncement struct {
+	ID      int64  `json:"id"`
+	Title   string `json:"title"`
+	Content string `json:"content"`
+	StartsAt *time.Time `json:"starts_at,omitempty"`
+	EndsAt   *time.Time `json:"ends_at,omitempty"`
+	ReadAt *time.Time `json:"read_at,omitempty"`
+	CreatedAt time.Time `json:"created_at"`
+	UpdatedAt time.Time `json:"updated_at"`
+}
+func AnnouncementFromService(a *service.Announcement) *Announcement {
+	if a == nil {
+		return nil
+	}
+	return &Announcement{
+		ID:        a.ID,
+		Title:     a.Title,
+		Content:   a.Content,
+		Status:    a.Status,
+		Targeting: a.Targeting,
+		StartsAt:  a.StartsAt,
+		EndsAt:    a.EndsAt,
+		CreatedBy: a.CreatedBy,
+		UpdatedBy: a.UpdatedBy,
+		CreatedAt: a.CreatedAt,
+		UpdatedAt: a.UpdatedAt,
+	}
+}
+func UserAnnouncementFromService(a *service.UserAnnouncement) *UserAnnouncement {
+	if a == nil {
+		return nil
+	}
+	return &UserAnnouncement{
+		ID:        a.Announcement.ID,
+		Title:     a.Announcement.Title,
+		Content:   a.Announcement.Content,
+		StartsAt:  a.Announcement.StartsAt,
+		EndsAt:    a.Announcement.EndsAt,
+		ReadAt:    a.ReadAt,
+		CreatedAt: a.Announcement.CreatedAt,
+		UpdatedAt: a.Announcement.UpdatedAt,
+	}
+}
--- a/backend/internal/handler/handler.go
+++ b/backend/internal/handler/handler.go
@@ -10,6 +10,7 @@ type AdminHandlers struct {
 	User             *admin.UserHandler
 	Group            *admin.GroupHandler
 	Account          *admin.AccountHandler
+	Announcement     *admin.AnnouncementHandler
 	OAuth            *admin.OAuthHandler
 	OpenAIOAuth      *admin.OpenAIOAuthHandler
 	GeminiOAuth      *admin.GeminiOAuthHandler
@@ -33,6 +34,7 @@ type Handlers struct {
 	Usage         *UsageHandler
 	Redeem        *RedeemHandler
 	Subscription  *SubscriptionHandler
+	Announcement  *AnnouncementHandler
 	Admin         *AdminHandlers
 	Gateway       *GatewayHandler
 	OpenAIGateway *OpenAIGatewayHandler

--- a/backend/internal/handler/wire.go
+++ b/backend/internal/handler/wire.go
@@ -13,6 +13,7 @@ func ProvideAdminHandlers(
 	userHandler *admin.UserHandler,
 	groupHandler *admin.GroupHandler,
 	accountHandler *admin.AccountHandler,
+	announcementHandler *admin.AnnouncementHandler,
 	oauthHandler *admin.OAuthHandler,
 	openaiOAuthHandler *admin.OpenAIOAuthHandler,
 	geminiOAuthHandler *admin.GeminiOAuthHandler,
@@ -32,6 +33,7 @@ func ProvideAdminHandlers(
 		User:             userHandler,
 		Group:            groupHandler,
 		Account:          accountHandler,
+		Announcement:     announcementHandler,
 		OAuth:            oauthHandler,
 		OpenAIOAuth:      openaiOAuthHandler,
 		GeminiOAuth:      geminiOAuthHandler,
@@ -66,6 +68,7 @@ func ProvideHandlers(
 	usageHandler *UsageHandler,
 	redeemHandler *RedeemHandler,
 	subscriptionHandler *SubscriptionHandler,
+	announcementHandler *AnnouncementHandler,
 	adminHandlers *AdminHandlers,
 	gatewayHandler *GatewayHandler,
 	openaiGatewayHandler *OpenAIGatewayHandler,
@@ -79,6 +82,7 @@ func ProvideHandlers(
 		Usage:         usageHandler,
 		Redeem:        redeemHandler,
 		Subscription:  subscriptionHandler,
+		Announcement:  announcementHandler,
 		Admin:         adminHandlers,
 		Gateway:       gatewayHandler,
 		OpenAIGateway: openaiGatewayHandler,
@@ -96,6 +100,7 @@ var ProviderSet = wire.NewSet(
 	NewUsageHandler,
 	NewRedeemHandler,
 	NewSubscriptionHandler,
+	NewAnnouncementHandler,
 	NewGatewayHandler,
 	NewOpenAIGatewayHandler,
 	NewTotpHandler,
@@ -106,6 +111,7 @@ var ProviderSet = wire.NewSet(
 	admin.NewUserHandler,
 	admin.NewGroupHandler,
 	admin.NewAccountHandler,
+	admin.NewAnnouncementHandler,
 	admin.NewOAuthHandler,
 	admin.NewOpenAIOAuthHandler,
 	admin.NewGeminiOAuthHandler,

--- a/backend/internal/repository/announcement_read_repo.go
+++ b/backend/internal/repository/announcement_read_repo.go
+package repository
+import (
+	"context"
+	"time"
+	dbent "github.com/Wei-Shaw/sub2api/ent"
+	"github.com/Wei-Shaw/sub2api/ent/announcementread"
+	"github.com/Wei-Shaw/sub2api/internal/service"
+)
+type announcementReadRepository struct {
+	client *dbent.Client
+}
+func NewAnnouncementReadRepository(client *dbent.Client) service.AnnouncementReadRepository {
+	return &announcementReadRepository{client: client}
+}
+func (r *announcementReadRepository) MarkRead(ctx context.Context, announcementID, userID int64, readAt time.Time) error {
+	client := clientFromContext(ctx, r.client)
+	return client.AnnouncementRead.Create().
+		SetAnnouncementID(announcementID).
+		SetUserID(userID).
+		SetReadAt(readAt).
+		OnConflictColumns(announcementread.FieldAnnouncementID, announcementread.FieldUserID).
+		DoNothing().
+		Exec(ctx)
+}
+func (r *announcementReadRepository) GetReadMapByUser(ctx context.Context, userID int64, announcementIDs []int64) (map[int64]time.Time, error) {
+	if len(announcementIDs) == 0 {
+		return map[int64]time.Time{}, nil
+	}
+	rows, err := r.client.AnnouncementRead.Query().
+		Where(
+			announcementread.UserIDEQ(userID),
+			announcementread.AnnouncementIDIn(announcementIDs...),
+		).
+		All(ctx)
+	if err != nil {
+		return nil, err
+	}
+	out := make(map[int64]time.Time, len(rows))
+	for i := range rows {
+		out[rows[i].AnnouncementID] = rows[i].ReadAt
+	}
+	return out, nil
+}
+func (r *announcementReadRepository) GetReadMapByUsers(ctx context.Context, announcementID int64, userIDs []int64) (map[int64]time.Time, error) {
+	if len(userIDs) == 0 {
+		return map[int64]time.Time{}, nil
+	}
+	rows, err := r.client.AnnouncementRead.Query().
+		Where(
+			announcementread.AnnouncementIDEQ(announcementID),
+			announcementread.UserIDIn(userIDs...),
+		).
+		All(ctx)
+	if err != nil {
+		return nil, err
+	}
+	out := make(map[int64]time.Time, len(rows))
+	for i := range rows {
+		out[rows[i].UserID] = rows[i].ReadAt
+	}
+	return out, nil
+}
+func (r *announcementReadRepository) CountByAnnouncementID(ctx context.Context, announcementID int64) (int64, error) {
+	count, err := r.client.AnnouncementRead.Query().
+		Where(announcementread.AnnouncementIDEQ(announcementID)).
+		Count(ctx)
+	if err != nil {
+		return 0, err
+	}
+	return int64(count), nil
+}
--- a/backend/internal/repository/announcement_repo.go
+++ b/backend/internal/repository/announcement_repo.go
+package repository
+import (
+	"context"
+	"time"
+	dbent "github.com/Wei-Shaw/sub2api/ent"
+	"github.com/Wei-Shaw/sub2api/ent/announcement"
+	"github.com/Wei-Shaw/sub2api/internal/pkg/pagination"
+	"github.com/Wei-Shaw/sub2api/internal/service"
+)
+type announcementRepository struct {
+	client *dbent.Client
+}
+func NewAnnouncementRepository(client *dbent.Client) service.AnnouncementRepository {
+	return &announcementRepository{client: client}
+}
+func (r *announcementRepository) Create(ctx context.Context, a *service.Announcement) error {
+	client := clientFromContext(ctx, r.client)
+	builder := client.Announcement.Create().
+		SetTitle(a.Title).
+		SetContent(a.Content).
+		SetStatus(a.Status).
+		SetTargeting(a.Targeting)
+	if a.StartsAt != nil {
+		builder.SetStartsAt(*a.StartsAt)
+	}
+	if a.EndsAt != nil {
+		builder.SetEndsAt(*a.EndsAt)
+	}
+	if a.CreatedBy != nil {
+		builder.SetCreatedBy(*a.CreatedBy)
+	}
+	if a.UpdatedBy != nil {
+		builder.SetUpdatedBy(*a.UpdatedBy)
+	}
+	created, err := builder.Save(ctx)
+	if err != nil {
+		return err
+	}
+	applyAnnouncementEntityToService(a, created)
+	return nil
+}
+func (r *announcementRepository) GetByID(ctx context.Context, id int64) (*service.Announcement, error) {
+	m, err := r.client.Announcement.Query().
+		Where(announcement.IDEQ(id)).
+		Only(ctx)
+	if err != nil {
+		return nil, translatePersistenceError(err, service.ErrAnnouncementNotFound, nil)
+	}
+	return announcementEntityToService(m), nil
+}
+func (r *announcementRepository) Update(ctx context.Context, a *service.Announcement) error {
+	client := clientFromContext(ctx, r.client)
+	builder := client.Announcement.UpdateOneID(a.ID).
+		SetTitle(a.Title).
+		SetContent(a.Content).
+		SetStatus(a.Status).
+		SetTargeting(a.Targeting)
+	if a.StartsAt != nil {
+		builder.SetStartsAt(*a.StartsAt)
+	} else {
+		builder.ClearStartsAt()
+	}
+	if a.EndsAt != nil {
+		builder.SetEndsAt(*a.EndsAt)
+	} else {
+		builder.ClearEndsAt()
+	}
+	if a.CreatedBy != nil {
+		builder.SetCreatedBy(*a.CreatedBy)
+	} else {
+		builder.ClearCreatedBy()
+	}
+	if a.UpdatedBy != nil {
+		builder.SetUpdatedBy(*a.UpdatedBy)
+	} else {
+		builder.ClearUpdatedBy()
+	}
+	updated, err := builder.Save(ctx)
+	if err != nil {
+		return translatePersistenceError(err, service.ErrAnnouncementNotFound, nil)
+	}
+	a.UpdatedAt = updated.UpdatedAt
+	return nil
+}
+func (r *announcementRepository) Delete(ctx context.Context, id int64) error {
+	client := clientFromContext(ctx, r.client)
+	_, err := client.Announcement.Delete().Where(announcement.IDEQ(id)).Exec(ctx)
+	return err
+}
+func (r *announcementRepository) List(
+	ctx context.Context,
+	params pagination.PaginationParams,
+	filters service.AnnouncementListFilters,
+) ([]service.Announcement, *pagination.PaginationResult, error) {
+	q := r.client.Announcement.Query()
+	if filters.Status != "" {
+		q = q.Where(announcement.StatusEQ(filters.Status))
+	}
+	if filters.Search != "" {
+		q = q.Where(
+			announcement.Or(
+				announcement.TitleContainsFold(filters.Search),
+				announcement.ContentContainsFold(filters.Search),
+			),
+		)
+	}
+	total, err := q.Count(ctx)
+	if err != nil {
+		return nil, nil, err
+	}
+	items, err := q.
+		Offset(params.Offset()).
+		Limit(params.Limit()).
+		Order(dbent.Desc(announcement.FieldID)).
+		All(ctx)
+	if err != nil {
+		return nil, nil, err
+	}
+	out := announcementEntitiesToService(items)
+	return out, paginationResultFromTotal(int64(total), params), nil
+}
+func (r *announcementRepository) ListActive(ctx context.Context, now time.Time) ([]service.Announcement, error) {
+	q := r.client.Announcement.Query().
+		Where(
+			announcement.StatusEQ(service.AnnouncementStatusActive),
+			announcement.Or(announcement.StartsAtIsNil(), announcement.StartsAtLTE(now)),
+			announcement.Or(announcement.EndsAtIsNil(), announcement.EndsAtGT(now)),
+		).
+		Order(dbent.Desc(announcement.FieldID))
+	items, err := q.All(ctx)
+	if err != nil {
+		return nil, err
+	}
+	return announcementEntitiesToService(items), nil
+}
+func applyAnnouncementEntityToService(dst *service.Announcement, src *dbent.Announcement) {
+	if dst == nil || src == nil {
+		return
+	}
+	dst.ID = src.ID
+	dst.CreatedAt = src.CreatedAt
+	dst.UpdatedAt = src.UpdatedAt
+}
+func announcementEntityToService(m *dbent.Announcement) *service.Announcement {
+	if m == nil {
+		return nil
+	}
+	return &service.Announcement{
+		ID:        m.ID,
+		Title:     m.Title,
+		Content:   m.Content,
+		Status:    m.Status,
+		Targeting: m.Targeting,
+		StartsAt:  m.StartsAt,
+		EndsAt:    m.EndsAt,
+		CreatedBy: m.CreatedBy,
+		UpdatedBy: m.UpdatedBy,
+		CreatedAt: m.CreatedAt,
+		UpdatedAt: m.UpdatedAt,
+	}
+}
+func announcementEntitiesToService(models []*dbent.Announcement) []service.Announcement {
+	out := make([]service.Announcement, 0, len(models))
+	for i := range models {
+		if s := announcementEntityToService(models[i]); s != nil {
+			out = append(out, *s)
+		}
+	}
+	return out
+}
--- a/backend/internal/repository/wire.go
+++ b/backend/internal/repository/wire.go
@@ -56,6 +56,8 @@ var ProviderSet = wire.NewSet(
 	NewProxyRepository,
 	NewRedeemCodeRepository,
 	NewPromoCodeRepository,
+	NewAnnouncementRepository,
+	NewAnnouncementReadRepository,
 	NewUsageLogRepository,
 	NewUsageCleanupRepository,
 	NewDashboardAggregationRepository,

--- a/backend/internal/server/routes/admin.go
+++ b/backend/internal/server/routes/admin.go
@@ -29,6 +29,9 @@ func RegisterAdminRoutes(
 		// 账号管理
 		registerAccountRoutes(admin, h)
+		// 公告管理
+		registerAnnouncementRoutes(admin, h)
 		// OpenAI OAuth
 		registerOpenAIOAuthRoutes(admin, h)
@@ -229,6 +232,18 @@ func registerAccountRoutes(admin *gin.RouterGroup, h *handler.Handlers) {
 	}
 }
+func registerAnnouncementRoutes(admin *gin.RouterGroup, h *handler.Handlers) {
+	announcements := admin.Group("/announcements")
+	{
+		announcements.GET("", h.Admin.Announcement.List)
+		announcements.POST("", h.Admin.Announcement.Create)
+		announcements.GET("/:id", h.Admin.Announcement.GetByID)
+		announcements.PUT("/:id", h.Admin.Announcement.Update)
+		announcements.DELETE("/:id", h.Admin.Announcement.Delete)
+		announcements.GET("/:id/read-status", h.Admin.Announcement.ListReadStatus)
+	}
+}
 func registerOpenAIOAuthRoutes(admin *gin.RouterGroup, h *handler.Handlers) {
 	openai := admin.Group("/openai")
 	{

--- a/backend/internal/server/routes/user.go
+++ b/backend/internal/server/routes/user.go
@@ -64,6 +64,13 @@ func RegisterUserRoutes(
 			usage.POST("/dashboard/api-keys-usage", h.Usage.DashboardAPIKeysUsage)
 		}
+		// 公告（用户可见）
+		announcements := authenticated.Group("/announcements")
+		{
+			announcements.GET("", h.Announcement.List)
+			announcements.POST("/:id/read", h.Announcement.MarkRead)
+		}
 		// 卡密兑换
 		redeem := authenticated.Group("/redeem")
 		{

--- a/backend/internal/service/announcement.go
+++ b/backend/internal/service/announcement.go
+package service
+import (
+	"context"
+	"time"
+	"github.com/Wei-Shaw/sub2api/internal/domain"
+	"github.com/Wei-Shaw/sub2api/internal/pkg/pagination"
+)
+const (
+	AnnouncementStatusDraft    = domain.AnnouncementStatusDraft
+	AnnouncementStatusActive   = domain.AnnouncementStatusActive
+	AnnouncementStatusArchived = domain.AnnouncementStatusArchived
+)
+const (
+	AnnouncementConditionTypeSubscription = domain.AnnouncementConditionTypeSubscription
+	AnnouncementConditionTypeBalance      = domain.AnnouncementConditionTypeBalance
+)
+const (
+	AnnouncementOperatorIn  = domain.AnnouncementOperatorIn
+	AnnouncementOperatorGT  = domain.AnnouncementOperatorGT
+	AnnouncementOperatorGTE = domain.AnnouncementOperatorGTE
+	AnnouncementOperatorLT  = domain.AnnouncementOperatorLT
+	AnnouncementOperatorLTE = domain.AnnouncementOperatorLTE
+	AnnouncementOperatorEQ  = domain.AnnouncementOperatorEQ
+)
+var (
+	ErrAnnouncementNotFound      = domain.ErrAnnouncementNotFound
+	ErrAnnouncementInvalidTarget = domain.ErrAnnouncementInvalidTarget
+)
+type AnnouncementTargeting = domain.AnnouncementTargeting
+type AnnouncementConditionGroup = domain.AnnouncementConditionGroup
+type AnnouncementCondition = domain.AnnouncementCondition
+type Announcement = domain.Announcement
+type AnnouncementListFilters struct {
+	Status string
+	Search string
+}
+type AnnouncementRepository interface {
+	Create(ctx context.Context, a *Announcement) error
+	GetByID(ctx context.Context, id int64) (*Announcement, error)
+	Update(ctx context.Context, a *Announcement) error
+	Delete(ctx context.Context, id int64) error
+	List(ctx context.Context, params pagination.PaginationParams, filters AnnouncementListFilters) ([]Announcement, *pagination.PaginationResult, error)
+	ListActive(ctx context.Context, now time.Time) ([]Announcement, error)
+}
+type AnnouncementReadRepository interface {
+	MarkRead(ctx context.Context, announcementID, userID int64, readAt time.Time) error
+	GetReadMapByUser(ctx context.Context, userID int64, announcementIDs []int64) (map[int64]time.Time, error)
+	GetReadMapByUsers(ctx context.Context, announcementID int64, userIDs []int64) (map[int64]time.Time, error)
+	CountByAnnouncementID(ctx context.Context, announcementID int64) (int64, error)
+}
--- a/backend/internal/service/announcement_service.go
+++ b/backend/internal/service/announcement_service.go
+package service
+import (
+	"context"
+	"fmt"
+	"sort"
+	"strings"
+	"time"
+	"github.com/Wei-Shaw/sub2api/internal/domain"
+	"github.com/Wei-Shaw/sub2api/internal/pkg/pagination"
+)
+type AnnouncementService struct {
+	announcementRepo AnnouncementRepository
+	readRepo         AnnouncementReadRepository
+	userRepo         UserRepository
+	userSubRepo      UserSubscriptionRepository
+}
+func NewAnnouncementService(
+	announcementRepo AnnouncementRepository,
+	readRepo AnnouncementReadRepository,
+	userRepo UserRepository,
+	userSubRepo UserSubscriptionRepository,
+) *AnnouncementService {
+	return &AnnouncementService{
+		announcementRepo: announcementRepo,
+		readRepo:         readRepo,
+		userRepo:         userRepo,
+		userSubRepo:      userSubRepo,
+	}
+}
+type CreateAnnouncementInput struct {
+	Title     string
+	Content   string
+	Status    string
+	Targeting AnnouncementTargeting
+	StartsAt  *time.Time
+	EndsAt    *time.Time
+	ActorID   *int64 // 管理员用户ID
+}
+type UpdateAnnouncementInput struct {
+	Title     *string
+	Content   *string
+	Status    *string
+	Targeting *AnnouncementTargeting
+	StartsAt  **time.Time
+	EndsAt    **time.Time
+	ActorID   *int64 // 管理员用户ID
+}
+type UserAnnouncement struct {
+	Announcement Announcement
+	ReadAt       *time.Time
+}
+type AnnouncementUserReadStatus struct {
+	UserID   int64      `json:"user_id"`
+	Email    string     `json:"email"`
+	Username string     `json:"username"`
+	Balance  float64    `json:"balance"`
+	Eligible bool       `json:"eligible"`
+	ReadAt   *time.Time `json:"read_at,omitempty"`
+}
+func (s *AnnouncementService) Create(ctx context.Context, input *CreateAnnouncementInput) (*Announcement, error) {
+	if input == nil {
+		return nil, fmt.Errorf("create announcement: nil input")
+	}
+	title := strings.TrimSpace(input.Title)
+	content := strings.TrimSpace(input.Content)
+	if title == "" || len(title) > 200 {
+		return nil, fmt.Errorf("create announcement: invalid title")
+	}
+	if content == "" {
+		return nil, fmt.Errorf("create announcement: content is required")
+	}
+	status := strings.TrimSpace(input.Status)
+	if status == "" {
+		status = AnnouncementStatusDraft
+	}
+	if !isValidAnnouncementStatus(status) {
+		return nil, fmt.Errorf("create announcement: invalid status")
+	}
+	targeting, err := domain.AnnouncementTargeting(input.Targeting).NormalizeAndValidate()
+	if err != nil {
+		return nil, err
+	}
+	if input.StartsAt != nil && input.EndsAt != nil {
+		if !input.StartsAt.Before(*input.EndsAt) {
+			return nil, fmt.Errorf("create announcement: starts_at must be before ends_at")
+		}
+	}
+	a := &Announcement{
+		Title:     title,
+		Content:   content,
+		Status:    status,
+		Targeting: targeting,
+		StartsAt:  input.StartsAt,
+		EndsAt:    input.EndsAt,
+	}
+	if input.ActorID != nil && *input.ActorID > 0 {
+		a.CreatedBy = input.ActorID
+		a.UpdatedBy = input.ActorID
+	}
+	if err := s.announcementRepo.Create(ctx, a); err != nil {
+		return nil, fmt.Errorf("create announcement: %w", err)
+	}
+	return a, nil
+}
+func (s *AnnouncementService) Update(ctx context.Context, id int64, input *UpdateAnnouncementInput) (*Announcement, error) {
+	if input == nil {
+		return nil, fmt.Errorf("update announcement: nil input")
+	}
+	a, err := s.announcementRepo.GetByID(ctx, id)
+	if err != nil {
+		return nil, err
+	}
+	if input.Title != nil {
+		title := strings.TrimSpace(*input.Title)
+		if title == "" || len(title) > 200 {
+			return nil, fmt.Errorf("update announcement: invalid title")
+		}
+		a.Title = title
+	}
+	if input.Content != nil {
+		content := strings.TrimSpace(*input.Content)
+		if content == "" {
+			return nil, fmt.Errorf("update announcement: content is required")
+		}
+		a.Content = content
+	}
+	if input.Status != nil {
+		status := strings.TrimSpace(*input.Status)
+		if !isValidAnnouncementStatus(status) {
+			return nil, fmt.Errorf("update announcement: invalid status")
+		}
+		a.Status = status
+	}
+	if input.Targeting != nil {
+		targeting, err := domain.AnnouncementTargeting(*input.Targeting).NormalizeAndValidate()
+		if err != nil {
+			return nil, err
+		}
+		a.Targeting = targeting
+	}
+	if input.StartsAt != nil {
+		a.StartsAt = *input.StartsAt
+	}
+	if input.EndsAt != nil {
+		a.EndsAt = *input.EndsAt
+	}
+	if a.StartsAt != nil && a.EndsAt != nil {
+		if !a.StartsAt.Before(*a.EndsAt) {
+			return nil, fmt.Errorf("update announcement: starts_at must be before ends_at")
+		}
+	}
+	if input.ActorID != nil && *input.ActorID > 0 {
+		a.UpdatedBy = input.ActorID
+	}
+	if err := s.announcementRepo.Update(ctx, a); err != nil {
+		return nil, fmt.Errorf("update announcement: %w", err)
+	}
+	return a, nil
+}
+func (s *AnnouncementService) Delete(ctx context.Context, id int64) error {
+	if err := s.announcementRepo.Delete(ctx, id); err != nil {
+		return fmt.Errorf("delete announcement: %w", err)
+	}
+	return nil
+}
+func (s *AnnouncementService) GetByID(ctx context.Context, id int64) (*Announcement, error) {
+	return s.announcementRepo.GetByID(ctx, id)
+}
+func (s *AnnouncementService) List(ctx context.Context, params pagination.PaginationParams, filters AnnouncementListFilters) ([]Announcement, *pagination.PaginationResult, error) {
+	return s.announcementRepo.List(ctx, params, filters)
+}
+func (s *AnnouncementService) ListForUser(ctx context.Context, userID int64, unreadOnly bool) ([]UserAnnouncement, error) {
+	user, err := s.userRepo.GetByID(ctx, userID)
+	if err != nil {
+		return nil, fmt.Errorf("get user: %w", err)
+	}
+	activeSubs, err := s.userSubRepo.ListActiveByUserID(ctx, userID)
+	if err != nil {
+		return nil, fmt.Errorf("list active subscriptions: %w", err)
+	}
+	activeGroupIDs := make(map[int64]struct{}, len(activeSubs))
+	for i := range activeSubs {
+		activeGroupIDs[activeSubs[i].GroupID] = struct{}{}
+	}
+	now := time.Now()
+	anns, err := s.announcementRepo.ListActive(ctx, now)
+	if err != nil {
+		return nil, fmt.Errorf("list active announcements: %w", err)
+	}
+	visible := make([]Announcement, 0, len(anns))
+	ids := make([]int64, 0, len(anns))
+	for i := range anns {
+		a := anns[i]
+		if !a.IsActiveAt(now) {
+			continue
+		}
+		if !a.Targeting.Matches(user.Balance, activeGroupIDs) {
+			continue
+		}
+		visible = append(visible, a)
+		ids = append(ids, a.ID)
+	}
+	if len(visible) == 0 {
+		return []UserAnnouncement{}, nil
+	}
+	readMap, err := s.readRepo.GetReadMapByUser(ctx, userID, ids)
+	if err != nil {
+		return nil, fmt.Errorf("get read map: %w", err)
+	}
+	out := make([]UserAnnouncement, 0, len(visible))
+	for i := range visible {
+		a := visible[i]
+		readAt, ok := readMap[a.ID]
+		if unreadOnly && ok {
+			continue
+		}
+		var ptr *time.Time
+		if ok {
+			t := readAt
+			ptr = &t
+		}
+		out = append(out, UserAnnouncement{
+			Announcement: a,
+			ReadAt:       ptr,
+		})
+	}
+	// 未读优先、同状态按创建时间倒序
+	sort.Slice(out, func(i, j int) bool {
+		ai, aj := out[i], out[j]
+		if (ai.ReadAt == nil) != (aj.ReadAt == nil) {
+			return ai.ReadAt == nil
+		}
+		return ai.Announcement.ID > aj.Announcement.ID
+	})
+	return out, nil
+}
+func (s *AnnouncementService) MarkRead(ctx context.Context, userID, announcementID int64) error {
+	// 安全：仅允许标记当前用户“可见”的公告
+	user, err := s.userRepo.GetByID(ctx, userID)
+	if err != nil {
+		return fmt.Errorf("get user: %w", err)
+	}
+	a, err := s.announcementRepo.GetByID(ctx, announcementID)
+	if err != nil {
+		return err
+	}
+	now := time.Now()
+	if !a.IsActiveAt(now) {
+		return ErrAnnouncementNotFound
+	}
+	activeSubs, err := s.userSubRepo.ListActiveByUserID(ctx, userID)
+	if err != nil {
+		return fmt.Errorf("list active subscriptions: %w", err)
+	}
+	activeGroupIDs := make(map[int64]struct{}, len(activeSubs))
+	for i := range activeSubs {
+		activeGroupIDs[activeSubs[i].GroupID] = struct{}{}
+	}
+	if !a.Targeting.Matches(user.Balance, activeGroupIDs) {
+		return ErrAnnouncementNotFound
+	}
+	if err := s.readRepo.MarkRead(ctx, announcementID, userID, now); err != nil {
+		return fmt.Errorf("mark read: %w", err)
+	}
+	return nil
+}
+func (s *AnnouncementService) ListUserReadStatus(
+	ctx context.Context,
+	announcementID int64,
+	params pagination.PaginationParams,
+	search string,
+) ([]AnnouncementUserReadStatus, *pagination.PaginationResult, error) {
+	ann, err := s.announcementRepo.GetByID(ctx, announcementID)
+	if err != nil {
+		return nil, nil, err
+	}
+	filters := UserListFilters{
+		Search: strings.TrimSpace(search),
+	}
+	users, page, err := s.userRepo.ListWithFilters(ctx, params, filters)
+	if err != nil {
+		return nil, nil, fmt.Errorf("list users: %w", err)
+	}
+	userIDs := make([]int64, 0, len(users))
+	for i := range users {
+		userIDs = append(userIDs, users[i].ID)
+	}
+	readMap, err := s.readRepo.GetReadMapByUsers(ctx, announcementID, userIDs)
+	if err != nil {
+		return nil, nil, fmt.Errorf("get read map: %w", err)
+	}
+	out := make([]AnnouncementUserReadStatus, 0, len(users))
+	for i := range users {
+		u := users[i]
+		subs, err := s.userSubRepo.ListActiveByUserID(ctx, u.ID)
+		if err != nil {
+			return nil, nil, fmt.Errorf("list active subscriptions: %w", err)
+		}
+		activeGroupIDs := make(map[int64]struct{}, len(subs))
+		for j := range subs {
+			activeGroupIDs[subs[j].GroupID] = struct{}{}
+		}
+		readAt, ok := readMap[u.ID]
+		var ptr *time.Time
+		if ok {
+			t := readAt
+			ptr = &t
+		}
+		out = append(out, AnnouncementUserReadStatus{
+			UserID:   u.ID,
+			Email:    u.Email,
+			Username: u.Username,
+			Balance:  u.Balance,
+			Eligible: domain.AnnouncementTargeting(ann.Targeting).Matches(u.Balance, activeGroupIDs),
+			ReadAt:   ptr,
+		})
+	}
+	return out, page, nil
+}
+func isValidAnnouncementStatus(status string) bool {
+	switch status {
+	case AnnouncementStatusDraft, AnnouncementStatusActive, AnnouncementStatusArchived:
+		return true
+	default:
+		return false
+	}
+}
--- a/backend/internal/service/announcement_targeting_test.go
+++ b/backend/internal/service/announcement_targeting_test.go
+package service
+import (
+	"testing"
+	"github.com/stretchr/testify/require"
+)
+func TestAnnouncementTargeting_Matches_EmptyMatchesAll(t *testing.T) {
+	var targeting AnnouncementTargeting
+	require.True(t, targeting.Matches(0, nil))
+	require.True(t, targeting.Matches(123.45, map[int64]struct{}{1: {}}))
+}
+func TestAnnouncementTargeting_NormalizeAndValidate_RejectsEmptyGroup(t *testing.T) {
+	targeting := AnnouncementTargeting{
+		AnyOf: []AnnouncementConditionGroup{
+			{AllOf: nil},
+		},
+	}
+	_, err := targeting.NormalizeAndValidate()
+	require.Error(t, err)
+	require.ErrorIs(t, err, ErrAnnouncementInvalidTarget)
+}
+func TestAnnouncementTargeting_NormalizeAndValidate_RejectsInvalidCondition(t *testing.T) {
+	targeting := AnnouncementTargeting{
+		AnyOf: []AnnouncementConditionGroup{
+			{
+				AllOf: []AnnouncementCondition{
+					{Type: "balance", Operator: "between", Value: 10},
+				},
+			},
+		},
+	}
+	_, err := targeting.NormalizeAndValidate()
+	require.Error(t, err)
+	require.ErrorIs(t, err, ErrAnnouncementInvalidTarget)
+}
+func TestAnnouncementTargeting_Matches_AndOrSemantics(t *testing.T) {
+	targeting := AnnouncementTargeting{
+		AnyOf: []AnnouncementConditionGroup{
+			{
+				AllOf: []AnnouncementCondition{
+					{Type: AnnouncementConditionTypeBalance, Operator: AnnouncementOperatorGTE, Value: 100},
+					{Type: AnnouncementConditionTypeSubscription, Operator: AnnouncementOperatorIn, GroupIDs: []int64{10}},
+				},
+			},
+			{
+				AllOf: []AnnouncementCondition{
+					{Type: AnnouncementConditionTypeBalance, Operator: AnnouncementOperatorLT, Value: 5},
+				},
+			},
+		},
+	}
+	// 命中第 2 组（balance < 5）
+	require.True(t, targeting.Matches(4.99, nil))
+	require.False(t, targeting.Matches(5, nil))
+	// 命中第 1 组（balance >= 100 AND 订阅 in [10]）
+	require.False(t, targeting.Matches(100, map[int64]struct{}{}))
+	require.False(t, targeting.Matches(99.9, map[int64]struct{}{10: {}}))
+	require.True(t, targeting.Matches(100, map[int64]struct{}{10: {}}))
+}
--- a/backend/internal/service/domain_constants.go
+++ b/backend/internal/service/domain_constants.go
 package service
+import "github.com/Wei-Shaw/sub2api/internal/domain"
 // Status constants
 const (
-	StatusActive   = "active"
+	StatusActive   = domain.StatusActive
-	StatusDisabled = "disabled"
+	StatusDisabled = domain.StatusDisabled
-	StatusError    = "error"
+	StatusError    = domain.StatusError
-	StatusUnused   = "unused"
+	StatusUnused   = domain.StatusUnused
-	StatusUsed     = "used"
+	StatusUsed     = domain.StatusUsed
-	StatusExpired  = "expired"
+	StatusExpired  = domain.StatusExpired
 )
 // Role constants
 const (
-	RoleAdmin = "admin"
+	RoleAdmin = domain.RoleAdmin
-	RoleUser  = "user"
+	RoleUser  = domain.RoleUser
 )
 // Platform constants
 const (
-	PlatformAnthropic   = "anthropic"
+	PlatformAnthropic   = domain.PlatformAnthropic
-	PlatformOpenAI      = "openai"
+	PlatformOpenAI      = domain.PlatformOpenAI
-	PlatformGemini      = "gemini"
+	PlatformGemini      = domain.PlatformGemini
-	PlatformAntigravity = "antigravity"
+	PlatformAntigravity = domain.PlatformAntigravity
 )
 // Account type constants
 const (
-	AccountTypeOAuth      = "oauth"       // OAuth类型账号（full scope: profile + inference）
+	AccountTypeOAuth      = domain.AccountTypeOAuth      // OAuth类型账号（full scope: profile + inference）
-	AccountTypeSetupToken = "setup-token" // Setup Token类型账号（inference only scope）
+	AccountTypeSetupToken = domain.AccountTypeSetupToken // Setup Token类型账号（inference only scope）
-	AccountTypeAPIKey     = "apikey"      // API Key类型账号
+	AccountTypeAPIKey     = domain.AccountTypeAPIKey     // API Key类型账号
 )
 // Redeem type constants
 const (
-	RedeemTypeBalance      = "balance"
+	RedeemTypeBalance      = domain.RedeemTypeBalance
-	RedeemTypeConcurrency  = "concurrency"
+	RedeemTypeConcurrency  = domain.RedeemTypeConcurrency
-	RedeemTypeSubscription = "subscription"
+	RedeemTypeSubscription = domain.RedeemTypeSubscription
 )
 // PromoCode status constants
 const (
-	PromoCodeStatusActive   = "active"
+	PromoCodeStatusActive   = domain.PromoCodeStatusActive
-	PromoCodeStatusDisabled = "disabled"
+	PromoCodeStatusDisabled = domain.PromoCodeStatusDisabled
 )
 // Admin adjustment type constants
 const (
-	AdjustmentTypeAdminBalance     = "admin_balance"     // 管理员调整余额
+	AdjustmentTypeAdminBalance     = domain.AdjustmentTypeAdminBalance     // 管理员调整余额
-	AdjustmentTypeAdminConcurrency = "admin_concurrency" // 管理员调整并发数
+	AdjustmentTypeAdminConcurrency = domain.AdjustmentTypeAdminConcurrency // 管理员调整并发数
 )
 // Group subscription type constants
 const (
-	SubscriptionTypeStandard     = "standard"     // 标准计费模式（按余额扣费）
+	SubscriptionTypeStandard     = domain.SubscriptionTypeStandard     // 标准计费模式（按余额扣费）
-	SubscriptionTypeSubscription = "subscription" // 订阅模式（按限额控制）
+	SubscriptionTypeSubscription = domain.SubscriptionTypeSubscription // 订阅模式（按限额控制）
 )
 // Subscription status constants
 const (
-	SubscriptionStatusActive    = "active"
+	SubscriptionStatusActive    = domain.SubscriptionStatusActive
-	SubscriptionStatusExpired   = "expired"
+	SubscriptionStatusExpired   = domain.SubscriptionStatusExpired
-	SubscriptionStatusSuspended = "suspended"
+	SubscriptionStatusSuspended = domain.SubscriptionStatusSuspended
 )
 // LinuxDoConnectSyntheticEmailDomain 是 LinuxDo Connect 用户的合成邮箱后缀（RFC 保留域名）。

--- a/backend/internal/service/wire.go
+++ b/backend/internal/service/wire.go
@@ -226,6 +226,7 @@ var ProviderSet = wire.NewSet(
 	ProvidePricingService,
 	NewBillingService,
 	NewBillingCacheService,
+	NewAnnouncementService,
 	NewAdminService,
 	NewGatewayService,
 	NewOpenAIGatewayService,

--- a/backend/migrations/045_add_announcements.sql
+++ b/backend/migrations/045_add_announcements.sql
+-- 创建公告表
+CREATE TABLE IF NOT EXISTS announcements (
+    id BIGSERIAL PRIMARY KEY,
+    title VARCHAR(200) NOT NULL,
+    content TEXT NOT NULL,
+    status VARCHAR(20) NOT NULL DEFAULT 'draft',
+    targeting JSONB NOT NULL DEFAULT '{}'::jsonb,
+    starts_at TIMESTAMPTZ DEFAULT NULL,
+    ends_at TIMESTAMPTZ DEFAULT NULL,
+    created_by BIGINT DEFAULT NULL REFERENCES users(id) ON DELETE SET NULL,
+    updated_by BIGINT DEFAULT NULL REFERENCES users(id) ON DELETE SET NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+-- 公告已读表
+CREATE TABLE IF NOT EXISTS announcement_reads (
+    id BIGSERIAL PRIMARY KEY,
+    announcement_id BIGINT NOT NULL REFERENCES announcements(id) ON DELETE CASCADE,
+    user_id BIGINT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    read_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    UNIQUE(announcement_id, user_id)
+);
+-- 索引
+CREATE INDEX IF NOT EXISTS idx_announcements_status ON announcements(status);
+CREATE INDEX IF NOT EXISTS idx_announcements_starts_at ON announcements(starts_at);
+CREATE INDEX IF NOT EXISTS idx_announcements_ends_at ON announcements(ends_at);
+CREATE INDEX IF NOT EXISTS idx_announcements_created_at ON announcements(created_at);
+CREATE INDEX IF NOT EXISTS idx_announcement_reads_announcement_id ON announcement_reads(announcement_id);
+CREATE INDEX IF NOT EXISTS idx_announcement_reads_user_id ON announcement_reads(user_id);
+CREATE INDEX IF NOT EXISTS idx_announcement_reads_read_at ON announcement_reads(read_at);
+COMMENT ON TABLE announcements IS '系统公告';
+COMMENT ON COLUMN announcements.status IS '状态: draft, active, archived';
+COMMENT ON COLUMN announcements.targeting IS '展示条件（JSON 规则）';
+COMMENT ON COLUMN announcements.starts_at IS '开始展示时间（为空表示立即生效）';
+COMMENT ON COLUMN announcements.ends_at IS '结束展示时间（为空表示永久生效）';
+COMMENT ON TABLE announcement_reads IS '公告已读记录';
+COMMENT ON COLUMN announcement_reads.read_at IS '用户首次已读时间';
--- a/frontend/src/api/admin/announcements.ts
+++ b/frontend/src/api/admin/announcements.ts
+/**
+ * Admin Announcements API endpoints
+ */
+import { apiClient } from '../client'
+import type {
+  Announcement,
+  AnnouncementUserReadStatus,
+  BasePaginationResponse,
+  CreateAnnouncementRequest,
+  UpdateAnnouncementRequest
+} from '@/types'
+export async function list(
+  page: number = 1,
+  pageSize: number = 20,
+  filters?: {
+    status?: string
+    search?: string
+  }
+): Promise<BasePaginationResponse<Announcement>> {
+  const { data } = await apiClient.get<BasePaginationResponse<Announcement>>('/admin/announcements', {
+    params: { page, page_size: pageSize, ...filters }
+  })
+  return data
+}
+export async function getById(id: number): Promise<Announcement> {
+  const { data } = await apiClient.get<Announcement>(`/admin/announcements/${id}`)
+  return data
+}
+export async function create(request: CreateAnnouncementRequest): Promise<Announcement> {
+  const { data } = await apiClient.post<Announcement>('/admin/announcements', request)
+  return data
+}
+export async function update(id: number, request: UpdateAnnouncementRequest): Promise<Announcement> {
+  const { data } = await apiClient.put<Announcement>(`/admin/announcements/${id}`, request)
+  return data
+}
+export async function deleteAnnouncement(id: number): Promise<{ message: string }> {
+  const { data } = await apiClient.delete<{ message: string }>(`/admin/announcements/${id}`)
+  return data
+}
+export async function getReadStatus(
+  id: number,
+  page: number = 1,
+  pageSize: number = 20,
+  search: string = ''
+): Promise<BasePaginationResponse<AnnouncementUserReadStatus>> {
+  const { data } = await apiClient.get<BasePaginationResponse<AnnouncementUserReadStatus>>(
+    `/admin/announcements/${id}/read-status`,
+    { params: { page, page_size: pageSize, search } }
+  )
+  return data
+}
+const announcementsAPI = {
+  list,
+  getById,
+  create,
+  update,
+  delete: deleteAnnouncement,
+  getReadStatus
+}
+export default announcementsAPI
--- a/frontend/src/api/admin/index.ts
+++ b/frontend/src/api/admin/index.ts
@@ -10,6 +10,7 @@ import accountsAPI from './accounts'
 import proxiesAPI from './proxies'
 import redeemAPI from './redeem'
 import promoAPI from './promo'
+import announcementsAPI from './announcements'
 import settingsAPI from './settings'
 import systemAPI from './system'
 import subscriptionsAPI from './subscriptions'
@@ -30,6 +31,7 @@ export const adminAPI = {
  proxies: proxiesAPI,
  redeem: redeemAPI,
  promo: promoAPI,
+  announcements: announcementsAPI,
  settings: settingsAPI,
  system: systemAPI,
  subscriptions: subscriptionsAPI,
@@ -48,6 +50,7 @@ export {
  proxiesAPI,
  redeemAPI,
  promoAPI,
+  announcementsAPI,
  settingsAPI,
  systemAPI,
  subscriptionsAPI,

--- a/frontend/src/api/announcements.ts
+++ b/frontend/src/api/announcements.ts
+/**
+ * User Announcements API endpoints
+ */
+import { apiClient } from './client'
+import type { UserAnnouncement } from '@/types'
+export async function list(unreadOnly: boolean = false): Promise<UserAnnouncement[]> {
+  const { data } = await apiClient.get<UserAnnouncement[]>('/announcements', {
+    params: unreadOnly ? { unread_only: 1 } : {}
+  })
+  return data
+}
+export async function markRead(id: number): Promise<{ message: string }> {
+  const { data } = await apiClient.post<{ message: string }>(`/announcements/${id}/read`)
+  return data
+}
+const announcementsAPI = {
+  list,
+  markRead
+}
+export default announcementsAPI