diff --git a/internal/repository/message_gateway.go b/internal/repository/message_gateway.go
new file mode 100644
index 00000000..0fdcb25a
--- /dev/null
+++ b/internal/repository/message_gateway.go
@@ -0,0 +1,152 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package repository
+
+import (
+	"context"
+	"errors"
+	"time"
+
+	db "github.com/Rain-kl/Wavelet/internal/infra/persistence"
+	"github.com/Rain-kl/Wavelet/internal/infra/persistence/idgen"
+	"github.com/Rain-kl/Wavelet/internal/model"
+	"gorm.io/gorm"
+)
+
+// CreateMessageChannel inserts a channel row.
+func CreateMessageChannel(ctx context.Context, ch *model.MessageChannel) error {
+	if ch.ID == 0 {
+		ch.ID = idgen.NextUint64ID()
+	}
+	return db.DB(ctx).Create(ch).Error
+}
+
+// UpdateMessageChannel saves a channel row.
+func UpdateMessageChannel(ctx context.Context, ch *model.MessageChannel) error {
+	return db.DB(ctx).Save(ch).Error
+}
+
+// GetMessageChannel loads a channel by id.
+func GetMessageChannel(ctx context.Context, id uint64) (*model.MessageChannel, error) {
+	var ch model.MessageChannel
+	if err := db.DB(ctx).Where("id = ?", id).First(&ch).Error; err != nil {
+		return nil, err
+	}
+	return &ch, nil
+}
+
+// ListMessageChannels returns all channels newest first.
+func ListMessageChannels(ctx context.Context) ([]model.MessageChannel, error) {
+	var rows []model.MessageChannel
+	if err := db.DB(ctx).Order("id DESC").Find(&rows).Error; err != nil {
+		return nil, err
+	}
+	return rows, nil
+}
+
+// DeleteMessageChannel removes pairings, bindings, then the channel.
+func DeleteMessageChannel(ctx context.Context, id uint64) error {
+	return db.DB(ctx).Transaction(func(tx *gorm.DB) error {
+		if err := tx.Where("channel_id = ?", id).Delete(&model.MessagePairingCode{}).Error; err != nil {
+			return err
+		}
+		if err := tx.Where("channel_id = ?", id).Delete(&model.MessageBinding{}).Error; err != nil {
+			return err
+		}
+		return tx.Delete(&model.MessageChannel{}, id).Error
+	})
+}
+
+// CreateMessageBinding inserts a binding.
+func CreateMessageBinding(ctx context.Context, b *model.MessageBinding) error {
+	if b.ID == 0 {
+		b.ID = idgen.NextUint64ID()
+	}
+	return db.DB(ctx).Create(b).Error
+}
+
+// GetBindingByChannelPlatform finds a binding for a platform user on a channel.
+func GetBindingByChannelPlatform(ctx context.Context, channelID uint64, platformUserID string) (*model.MessageBinding, error) {
+	var b model.MessageBinding
+	err := db.DB(ctx).Where("channel_id = ? AND platform_user_id = ?", channelID, platformUserID).First(&b).Error
+	if err != nil {
+		return nil, err
+	}
+	return &b, nil
+}
+
+// ListBindingsByUser lists bindings for a Wavelet user.
+func ListBindingsByUser(ctx context.Context, userID uint64) ([]model.MessageBinding, error) {
+	var rows []model.MessageBinding
+	if err := db.DB(ctx).Where("user_id = ?", userID).Order("id DESC").Find(&rows).Error; err != nil {
+		return nil, err
+	}
+	return rows, nil
+}
+
+// GetMessageBinding loads a binding by id.
+func GetMessageBinding(ctx context.Context, id uint64) (*model.MessageBinding, error) {
+	var b model.MessageBinding
+	if err := db.DB(ctx).Where("id = ?", id).First(&b).Error; err != nil {
+		return nil, err
+	}
+	return &b, nil
+}
+
+// DeleteMessageBinding deletes a binding by id.
+func DeleteMessageBinding(ctx context.Context, id uint64) error {
+	return db.DB(ctx).Delete(&model.MessageBinding{}, id).Error
+}
+
+// UpsertPairingCode reuses an unexpired code for the same channel+platform user.
+func UpsertPairingCode(ctx context.Context, channelID uint64, platformUserID, code string, expiresAt time.Time) (*model.MessagePairingCode, error) {
+	var existing model.MessagePairingCode
+	err := db.DB(ctx).
+		Where("channel_id = ? AND platform_user_id = ? AND expires_at > ?", channelID, platformUserID, time.Now()).
+		First(&existing).Error
+	if err == nil {
+		return &existing, nil
+	}
+	if !errors.Is(err, gorm.ErrRecordNotFound) {
+		return nil, err
+	}
+	row := &model.MessagePairingCode{
+		Code:           code,
+		ChannelID:      channelID,
+		PlatformUserID: platformUserID,
+		ExpiresAt:      expiresAt,
+	}
+	if err := db.DB(ctx).Create(row).Error; err != nil {
+		return nil, err
+	}
+	return row, nil
+}
+
+// GetPairingCode loads a pairing code by normalized code string.
+func GetPairingCode(ctx context.Context, code string) (*model.MessagePairingCode, error) {
+	var row model.MessagePairingCode
+	if err := db.DB(ctx).Where("code = ?", code).First(&row).Error; err != nil {
+		return nil, err
+	}
+	return &row, nil
+}
+
+// DeletePairingCode removes a pairing code.
+func DeletePairingCode(ctx context.Context, code string) error {
+	return db.DB(ctx).Where("code = ?", code).Delete(&model.MessagePairingCode{}).Error
+}
+
+// DeleteExpiredPairingCodes removes expired pairing rows.
+func DeleteExpiredPairingCodes(ctx context.Context) error {
+	return db.DB(ctx).Where("expires_at <= ?", time.Now()).Delete(&model.MessagePairingCode{}).Error
+}
+
+// ListEnabledMessageChannels returns enabled channels.
+func ListEnabledMessageChannels(ctx context.Context) ([]model.MessageChannel, error) {
+	var rows []model.MessageChannel
+	if err := db.DB(ctx).Where("enabled = ?", true).Find(&rows).Error; err != nil {
+		return nil, err
+	}
+	return rows, nil
+}
diff --git a/internal/repository/message_gateway_test.go b/internal/repository/message_gateway_test.go
new file mode 100644
index 00000000..74e14473
--- /dev/null
+++ b/internal/repository/message_gateway_test.go
@@ -0,0 +1,30 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package repository_test
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/Rain-kl/Wavelet/internal/repository"
+	"github.com/Rain-kl/Wavelet/internal/testhelper"
+)
+
+func TestUpsertPairingCode_ReusesUnexpired(t *testing.T) {
+	_, _, cleanup := testhelper.SetupTestEnvironment(t)
+	defer cleanup()
+	ctx := context.Background()
+	first, err := repository.UpsertPairingCode(ctx, 1, "tg-1", "ABCD1234", time.Now().Add(15*time.Minute))
+	if err != nil {
+		t.Fatal(err)
+	}
+	second, err := repository.UpsertPairingCode(ctx, 1, "tg-1", "ZZZZ9999", time.Now().Add(15*time.Minute))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if first.Code != second.Code || first.Code != "ABCD1234" {
+		t.Fatalf("reuse failed: %+v %+v", first, second)
+	}
+}