diff --git a/server/internal/pay/webhook.go b/server/internal/pay/webhook.go
index a91de4d..7cfe6f0 100644
--- a/server/internal/pay/webhook.go
+++ b/server/internal/pay/webhook.go
@@ -35,6 +35,7 @@ type WebhookHandler struct {
 	tolerance time.Duration
 	nonceTTL  time.Duration
 	now       func() time.Time // 测试注入
+	rewarder  Rewarder         // 可选:首充邀请奖励钩子(nil 则跳过)
 }
 
 func NewWebhookHandler(store *Store, granter Granter, db *sql.DB, rdb *redis.Client,
@@ -43,6 +44,14 @@ func NewWebhookHandler(store *Store, granter Granter, db *sql.DB, rdb *redis.Cli
 		system: system, secret: secret, tolerance: tolerance, nonceTTL: nonceTTL, now: time.Now}
 }
 
+// Rewarder(可选)在首充同事务内发放邀请首充奖励;nil 则跳过。
+type Rewarder interface {
+	OnFirstPaidTx(ctx context.Context, tx *sql.Tx, inviteeID int64, now time.Time) error
+}
+
+// SetRewarder 挂载首充邀请奖励钩子(reward.Service 满足此接口)。
+func (h *WebhookHandler) SetRewarder(r Rewarder) { h.rewarder = r }
+
 // webhookEvent 对应 pay settle.go::enqueuePaymentSucceeded 的 payload
 // (注意:payment.succeeded 无 refund_id 字段)。
 type webhookEvent struct {
@@ -172,5 +181,10 @@ func (h *WebhookHandler) settle(ctx context.Context, ev *webhookEvent) error {
 	if err := h.store.MarkPaidTx(ctx, tx, purchaseID, ev.AmountMinor, ev.Currency, ev.Channel, subID, paidAt); err != nil {
 		return err
 	}
+	if h.rewarder != nil {
+		if err := h.rewarder.OnFirstPaidTx(ctx, tx, userID, h.now().UTC()); err != nil {
+			return err // 同事务:发奖失败则整笔回滚,webhook 重试
+		}
+	}
 	return tx.Commit()
 }
diff --git a/server/internal/pay/webhook_referral_sqlite_test.go b/server/internal/pay/webhook_referral_sqlite_test.go
new file mode 100644
index 0000000..4f41129
--- /dev/null
+++ b/server/internal/pay/webhook_referral_sqlite_test.go
@@ -0,0 +1,48 @@
+package pay
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/wangjia/pangolin/server/internal/codes"
+	"github.com/wangjia/pangolin/server/internal/reward"
+)
+
+func TestSettle_FirstPaidGrantsReferralBonus(t *testing.T) {
+	h, db, _ := newWebhookRig(t)       // 复用本包 rig;rig 里 seedUser(1)
+	seedUser(t, db, 2, "invitee-uuid") // 被邀请人 = 付费者
+	// 建 referral: inviter=1, invitee=2, 已 reg_rewarded
+	now := time.Now().UTC()
+	if _, err := db.Exec(`INSERT INTO referrals (inviter_id,invitee_id,status,reg_rewarded_at,created_at) VALUES (1,2,'reg_rewarded',?,?)`, now, now); err != nil {
+		t.Fatalf("seed referral: %v", err)
+	}
+	// 装 rewarder
+	g := codes.NewService(codes.NewStore(db), nil, 5, time.Hour)
+	rw := reward.NewService(db, reward.NewStore(db), g, reward.Config{RegDays: 3, PaidDays: 7, TgDays: 3, RegMonthlyCap: 10}, time.Now)
+	h.SetRewarder(rw)
+
+	// 触发 settle(照本包已有 webhook 测试构造 ev:invitee=2 的一笔 paid;biz_ref=其 uuid)
+	err := h.settle(context.Background(), &webhookEvent{
+		ProductBizCode: "pro_month", OutTradeNo: "ot-1", BizRef: "invitee-uuid",
+		Channel: "nezha", AmountMinor: 600, Currency: "CNY", PaidAt: now.Format(time.RFC3339),
+	})
+	if err != nil {
+		t.Fatalf("settle: %v", err)
+	}
+
+	var status string
+	if err := db.QueryRow(`SELECT status FROM referrals WHERE invitee_id=2`).Scan(&status); err != nil {
+		t.Fatalf("query referral status: %v", err)
+	}
+	if status != "paid_rewarded" {
+		t.Fatalf("status=%q, want paid_rewarded", status)
+	}
+	var fp int
+	if err := db.QueryRow(`SELECT COUNT(*) FROM users WHERE id=2 AND first_paid_at IS NOT NULL`).Scan(&fp); err != nil {
+		t.Fatalf("query first_paid_at: %v", err)
+	}
+	if fp != 1 {
+		t.Fatalf("first_paid_at not set")
+	}
+}
diff --git a/server/internal/reward/service.go b/server/internal/reward/service.go
index 48a0298..65bc574 100644
--- a/server/internal/reward/service.go
+++ b/server/internal/reward/service.go
@@ -114,3 +114,23 @@ func (s *Service) OnRegister(ctx context.Context, inviteeID int64, inviteCode, d
 		slog.Warn("reward: commit failed", "err", err)
 	}
 }
+
+// OnFirstPaidTx 在 pay webhook 的同一事务内调用:标记 first_paid_at,若确为首充且该用户
+// 是被邀请人(referral 命中且未发过首充奖)→ 发首充段双方各 PaidDays 天。幂等。
+func (s *Service) OnFirstPaidTx(ctx context.Context, tx *sql.Tx, inviteeID int64, now time.Time) error {
+	first, err := s.st.MarkFirstPaidTx(ctx, tx, inviteeID, now)
+	if err != nil || !first {
+		return err // 非首充 → 不发
+	}
+	inviterID, status, ok, err := s.st.ReferralByInvitee(ctx, tx, inviteeID)
+	if err != nil || !ok || status == "paid_rewarded" || status == "rejected" {
+		return err // 无邀请关系 / 已发过 / 被拒 → 不发
+	}
+	if _, _, err := s.g.GrantRewardTx(ctx, tx, inviterID, s.cfg.PaidDays, "invite", "invite_paid_inviter", "ref-paid-inviter"); err != nil {
+		return err
+	}
+	if _, _, err := s.g.GrantRewardTx(ctx, tx, inviteeID, s.cfg.PaidDays, "invite", "invite_paid_invitee", "ref-paid-invitee"); err != nil {
+		return err
+	}
+	return s.st.MarkPaidRewardedTx(ctx, tx, inviteeID, now)
+}