diff --git a/db/db.go b/db/db.go
index e21b0590..3b6585c1 100644
--- a/db/db.go
+++ b/db/db.go
@@ -91,3 +91,36 @@ func extractDurationParam(q url.Values, key string, defaultValue time.Duration)
 	}
 	return d, nil
 }
+
+// ExecTx executes a function within a database transaction. If the function returns an error,
+// the transaction is rolled back. Otherwise, the transaction is committed.
+func ExecTx(db *sql.DB, f func(tx *sql.Tx) error) error {
+	tx, err := db.Begin()
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+	if err := f(tx); err != nil {
+		return err
+	}
+	return tx.Commit()
+}
+
+// QueryTx executes a function within a database transaction and returns the result. If the function
+// returns an error, the transaction is rolled back. Otherwise, the transaction is committed.
+func QueryTx[T any](db *sql.DB, f func(tx *sql.Tx) (T, error)) (T, error) {
+	tx, err := db.Begin()
+	if err != nil {
+		var zero T
+		return zero, err
+	}
+	defer tx.Rollback()
+	t, err := f(tx)
+	if err != nil {
+		return t, err
+	}
+	if err := tx.Commit(); err != nil {
+		return t, err
+	}
+	return t, nil
+}
diff --git a/message/cache.go b/message/cache.go
index 953a6f7f..3b12af3e 100644
--- a/message/cache.go
+++ b/message/cache.go
@@ -9,6 +9,7 @@ import (
 	"sync"
 	"time"
 
+	"heckel.io/ntfy/v2/db"
 	"heckel.io/ntfy/v2/log"
 	"heckel.io/ntfy/v2/model"
 	"heckel.io/ntfy/v2/util"
@@ -334,17 +335,14 @@ func (c *Cache) Topics() ([]string, error) {
 func (c *Cache) DeleteMessages(ids ...string) error {
 	c.maybeLock()
 	defer c.maybeUnlock()
-	tx, err := c.db.Begin()
-	if err != nil {
-		return err
-	}
-	defer tx.Rollback()
-	for _, id := range ids {
-		if _, err := tx.Exec(c.queries.deleteMessage, id); err != nil {
-			return err
+	return db.ExecTx(c.db, func(tx *sql.Tx) error {
+		for _, id := range ids {
+			if _, err := tx.Exec(c.queries.deleteMessage, id); err != nil {
+				return err
+			}
 		}
-	}
-	return tx.Commit()
+		return nil
+	})
 }
 
 // DeleteScheduledBySequenceID deletes unpublished (scheduled) messages with the given topic and sequence ID.
@@ -352,54 +350,43 @@ func (c *Cache) DeleteMessages(ids ...string) error {
 func (c *Cache) DeleteScheduledBySequenceID(topic, sequenceID string) ([]string, error) {
 	c.maybeLock()
 	defer c.maybeUnlock()
-	tx, err := c.db.Begin()
-	if err != nil {
-		return nil, err
-	}
-	defer tx.Rollback()
-	// First, get the message IDs of scheduled messages to be deleted
-	rows, err := tx.Query(c.queries.selectScheduledMessageIDsBySeqID, topic, sequenceID)
-	if err != nil {
-		return nil, err
-	}
-	defer rows.Close()
-	ids := make([]string, 0)
-	for rows.Next() {
-		var id string
-		if err := rows.Scan(&id); err != nil {
+	return db.QueryTx(c.db, func(tx *sql.Tx) ([]string, error) {
+		rows, err := tx.Query(c.queries.selectScheduledMessageIDsBySeqID, topic, sequenceID)
+		if err != nil {
 			return nil, err
 		}
-		ids = append(ids, id)
-	}
-	if err := rows.Err(); err != nil {
-		return nil, err
-	}
-	rows.Close() // Close rows before executing delete in same transaction
-	// Then delete the messages
-	if _, err := tx.Exec(c.queries.deleteScheduledBySequenceID, topic, sequenceID); err != nil {
-		return nil, err
-	}
-	if err := tx.Commit(); err != nil {
-		return nil, err
-	}
-	return ids, nil
+		defer rows.Close()
+		ids := make([]string, 0)
+		for rows.Next() {
+			var id string
+			if err := rows.Scan(&id); err != nil {
+				return nil, err
+			}
+			ids = append(ids, id)
+		}
+		if err := rows.Err(); err != nil {
+			return nil, err
+		}
+		rows.Close() // Close rows before executing delete in same transaction
+		if _, err := tx.Exec(c.queries.deleteScheduledBySequenceID, topic, sequenceID); err != nil {
+			return nil, err
+		}
+		return ids, nil
+	})
 }
 
 // ExpireMessages marks messages in the given topics as expired
 func (c *Cache) ExpireMessages(topics ...string) error {
 	c.maybeLock()
 	defer c.maybeUnlock()
-	tx, err := c.db.Begin()
-	if err != nil {
-		return err
-	}
-	defer tx.Rollback()
-	for _, t := range topics {
-		if _, err := tx.Exec(c.queries.updateMessagesForTopicExpiry, time.Now().Unix()-1, t); err != nil {
-			return err
+	return db.ExecTx(c.db, func(tx *sql.Tx) error {
+		for _, t := range topics {
+			if _, err := tx.Exec(c.queries.updateMessagesForTopicExpiry, time.Now().Unix()-1, t); err != nil {
+				return err
+			}
 		}
-	}
-	return tx.Commit()
+		return nil
+	})
 }
 
 // AttachmentsExpired returns message IDs with expired attachments that have not been deleted
@@ -427,17 +414,14 @@ func (c *Cache) AttachmentsExpired() ([]string, error) {
 func (c *Cache) MarkAttachmentsDeleted(ids ...string) error {
 	c.maybeLock()
 	defer c.maybeUnlock()
-	tx, err := c.db.Begin()
-	if err != nil {
-		return err
-	}
-	defer tx.Rollback()
-	for _, id := range ids {
-		if _, err := tx.Exec(c.queries.updateAttachmentDeleted, id); err != nil {
-			return err
+	return db.ExecTx(c.db, func(tx *sql.Tx) error {
+		for _, id := range ids {
+			if _, err := tx.Exec(c.queries.updateAttachmentDeleted, id); err != nil {
+				return err
+			}
 		}
-	}
-	return tx.Commit()
+		return nil
+	})
 }
 
 // AttachmentBytesUsedBySender returns the total size of active attachments sent by the given sender
diff --git a/message/cache_postgres_schema.go b/message/cache_postgres_schema.go
index 4b5730a0..4a539d0e 100644
--- a/message/cache_postgres_schema.go
+++ b/message/cache_postgres_schema.go
@@ -3,6 +3,8 @@ package message
 import (
 	"database/sql"
 	"fmt"
+
+	"heckel.io/ntfy/v2/db"
 )
 
 // Initial PostgreSQL schema
@@ -55,34 +57,29 @@ const (
 
 // PostgreSQL schema management queries
 const (
-	pgCurrentSchemaVersion           = 14
+	postgresCurrentSchemaVersion     = 14
 	postgresInsertSchemaVersionQuery = `INSERT INTO schema_version (store, version) VALUES ('message', $1)`
 	postgresSelectSchemaVersionQuery = `SELECT version FROM schema_version WHERE store = 'message'`
 )
 
 func setupPostgres(db *sql.DB) error {
 	var schemaVersion int
-	err := db.QueryRow(postgresSelectSchemaVersionQuery).Scan(&schemaVersion)
-	if err != nil {
+	if err := db.QueryRow(postgresSelectSchemaVersionQuery).Scan(&schemaVersion); err != nil {
 		return setupNewPostgresDB(db)
-	}
-	if schemaVersion > pgCurrentSchemaVersion {
-		return fmt.Errorf("unexpected schema version: version %d is higher than current version %d", schemaVersion, pgCurrentSchemaVersion)
+	} else if schemaVersion > postgresCurrentSchemaVersion {
+		return fmt.Errorf("unexpected schema version: version %d is higher than current version %d", schemaVersion, postgresCurrentSchemaVersion)
 	}
 	return nil
 }
 
-func setupNewPostgresDB(db *sql.DB) error {
-	tx, err := db.Begin()
-	if err != nil {
-		return err
-	}
-	defer tx.Rollback()
-	if _, err := tx.Exec(postgresCreateTablesQuery); err != nil {
-		return err
-	}
-	if _, err := tx.Exec(postgresInsertSchemaVersionQuery, pgCurrentSchemaVersion); err != nil {
-		return err
-	}
-	return tx.Commit()
+func setupNewPostgresDB(sqlDB *sql.DB) error {
+	return db.ExecTx(sqlDB, func(tx *sql.Tx) error {
+		if _, err := tx.Exec(postgresCreateTablesQuery); err != nil {
+			return err
+		}
+		if _, err := tx.Exec(postgresInsertSchemaVersionQuery, postgresCurrentSchemaVersion); err != nil {
+			return err
+		}
+		return nil
+	})
 }
diff --git a/message/cache_sqlite_schema.go b/message/cache_sqlite_schema.go
index 00a26c09..da744887 100644
--- a/message/cache_sqlite_schema.go
+++ b/message/cache_sqlite_schema.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"time"
 
+	"heckel.io/ntfy/v2/db"
 	"heckel.io/ntfy/v2/log"
 )
 
@@ -382,85 +383,70 @@ func sqliteMigrateFrom8(db *sql.DB, _ time.Duration) error {
 	return nil
 }
 
-func sqliteMigrateFrom9(db *sql.DB, cacheDuration time.Duration) error {
+func sqliteMigrateFrom9(sqlDB *sql.DB, cacheDuration time.Duration) error {
 	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 9 to 10")
-	tx, err := db.Begin()
-	if err != nil {
-		return err
-	}
-	defer tx.Rollback()
-	if _, err := tx.Exec(sqliteMigrate9To10AlterMessagesTableQuery); err != nil {
-		return err
-	}
-	if _, err := tx.Exec(sqliteMigrate9To10UpdateMessageExpiryQuery, int64(cacheDuration.Seconds())); err != nil {
-		return err
-	}
-	if _, err := tx.Exec(sqliteUpdateSchemaVersionQuery, 10); err != nil {
-		return err
-	}
-	return tx.Commit()
+	return db.ExecTx(sqlDB, func(tx *sql.Tx) error {
+		if _, err := tx.Exec(sqliteMigrate9To10AlterMessagesTableQuery); err != nil {
+			return err
+		}
+		if _, err := tx.Exec(sqliteMigrate9To10UpdateMessageExpiryQuery, int64(cacheDuration.Seconds())); err != nil {
+			return err
+		}
+		if _, err := tx.Exec(sqliteUpdateSchemaVersionQuery, 10); err != nil {
+			return err
+		}
+		return nil
+	})
 }
 
-func sqliteMigrateFrom10(db *sql.DB, _ time.Duration) error {
+func sqliteMigrateFrom10(sqlDB *sql.DB, _ time.Duration) error {
 	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 10 to 11")
-	tx, err := db.Begin()
-	if err != nil {
-		return err
-	}
-	defer tx.Rollback()
-	if _, err := tx.Exec(sqliteMigrate10To11AlterMessagesTableQuery); err != nil {
-		return err
-	}
-	if _, err := tx.Exec(sqliteUpdateSchemaVersionQuery, 11); err != nil {
-		return err
-	}
-	return tx.Commit()
+	return db.ExecTx(sqlDB, func(tx *sql.Tx) error {
+		if _, err := tx.Exec(sqliteMigrate10To11AlterMessagesTableQuery); err != nil {
+			return err
+		}
+		if _, err := tx.Exec(sqliteUpdateSchemaVersionQuery, 11); err != nil {
+			return err
+		}
+		return nil
+	})
 }
 
-func sqliteMigrateFrom11(db *sql.DB, _ time.Duration) error {
+func sqliteMigrateFrom11(sqlDB *sql.DB, _ time.Duration) error {
 	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 11 to 12")
-	tx, err := db.Begin()
-	if err != nil {
-		return err
-	}
-	defer tx.Rollback()
-	if _, err := tx.Exec(sqliteMigrate11To12AlterMessagesTableQuery); err != nil {
-		return err
-	}
-	if _, err := tx.Exec(sqliteUpdateSchemaVersionQuery, 12); err != nil {
-		return err
-	}
-	return tx.Commit()
+	return db.ExecTx(sqlDB, func(tx *sql.Tx) error {
+		if _, err := tx.Exec(sqliteMigrate11To12AlterMessagesTableQuery); err != nil {
+			return err
+		}
+		if _, err := tx.Exec(sqliteUpdateSchemaVersionQuery, 12); err != nil {
+			return err
+		}
+		return nil
+	})
 }
 
-func sqliteMigrateFrom12(db *sql.DB, _ time.Duration) error {
+func sqliteMigrateFrom12(sqlDB *sql.DB, _ time.Duration) error {
 	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 12 to 13")
-	tx, err := db.Begin()
-	if err != nil {
-		return err
-	}
-	defer tx.Rollback()
-	if _, err := tx.Exec(sqliteMigrate12To13AlterMessagesTableQuery); err != nil {
-		return err
-	}
-	if _, err := tx.Exec(sqliteUpdateSchemaVersionQuery, 13); err != nil {
-		return err
-	}
-	return tx.Commit()
+	return db.ExecTx(sqlDB, func(tx *sql.Tx) error {
+		if _, err := tx.Exec(sqliteMigrate12To13AlterMessagesTableQuery); err != nil {
+			return err
+		}
+		if _, err := tx.Exec(sqliteUpdateSchemaVersionQuery, 13); err != nil {
+			return err
+		}
+		return nil
+	})
 }
 
-func sqliteMigrateFrom13(db *sql.DB, _ time.Duration) error {
+func sqliteMigrateFrom13(sqlDB *sql.DB, _ time.Duration) error {
 	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 13 to 14")
-	tx, err := db.Begin()
-	if err != nil {
-		return err
-	}
-	defer tx.Rollback()
-	if _, err := tx.Exec(sqliteMigrate13To14AlterMessagesTableQuery); err != nil {
-		return err
-	}
-	if _, err := tx.Exec(sqliteUpdateSchemaVersionQuery, 14); err != nil {
-		return err
-	}
-	return tx.Commit()
+	return db.ExecTx(sqlDB, func(tx *sql.Tx) error {
+		if _, err := tx.Exec(sqliteMigrate13To14AlterMessagesTableQuery); err != nil {
+			return err
+		}
+		if _, err := tx.Exec(sqliteUpdateSchemaVersionQuery, 14); err != nil {
+			return err
+		}
+		return nil
+	})
 }
diff --git a/user/manager.go b/user/manager.go
index a1412be3..cd37cb3b 100644
--- a/user/manager.go
+++ b/user/manager.go
@@ -13,6 +13,7 @@ import (
 	"time"
 
 	"golang.org/x/crypto/bcrypt"
+	"heckel.io/ntfy/v2/db"
 	"heckel.io/ntfy/v2/log"
 	"heckel.io/ntfy/v2/payments"
 	"heckel.io/ntfy/v2/util"
@@ -122,7 +123,7 @@ func (a *Manager) AddUser(username, password string, role Role, hashed bool) err
 	if err != nil {
 		return err
 	}
-	return execTx(a.db, func(tx *sql.Tx) error {
+	return db.ExecTx(a.db, func(tx *sql.Tx) error {
 		return a.addUserTx(tx, username, hash, role, false)
 	})
 }
@@ -150,7 +151,7 @@ func (a *Manager) RemoveUser(username string) error {
 	if err := a.CanChangeUser(username); err != nil {
 		return err
 	}
-	return execTx(a.db, func(tx *sql.Tx) error {
+	return db.ExecTx(a.db, func(tx *sql.Tx) error {
 		return a.removeUserTx(tx, username)
 	})
 }
@@ -173,7 +174,7 @@ func (a *Manager) MarkUserRemoved(user *User) error {
 	if !AllowedUsername(user.Name) {
 		return ErrInvalidArgument
 	}
-	return execTx(a.db, func(tx *sql.Tx) error {
+	return db.ExecTx(a.db, func(tx *sql.Tx) error {
 		if err := a.resetUserAccessTx(tx, user.Name); err != nil {
 			return err
 		}
@@ -205,7 +206,7 @@ func (a *Manager) ChangePassword(username, password string, hashed bool) error {
 	if err != nil {
 		return err
 	}
-	return execTx(a.db, func(tx *sql.Tx) error {
+	return db.ExecTx(a.db, func(tx *sql.Tx) error {
 		return a.changePasswordHashTx(tx, username, hash)
 	})
 }
@@ -224,7 +225,7 @@ func (a *Manager) ChangeRole(username string, role Role) error {
 	if err := a.CanChangeUser(username); err != nil {
 		return err
 	}
-	return execTx(a.db, func(tx *sql.Tx) error {
+	return db.ExecTx(a.db, func(tx *sql.Tx) error {
 		return a.changeRoleTx(tx, username, role)
 	})
 }
@@ -365,7 +366,7 @@ func (a *Manager) writeUserStatsQueue() error {
 	a.statsQueue = make(map[string]*Stats)
 	a.mu.Unlock()
 
-	return execTx(a.db, func(tx *sql.Tx) error {
+	return db.ExecTx(a.db, func(tx *sql.Tx) error {
 		log.Tag(tag).Debug("Writing user stats queue for %d user(s)", len(statsQueue))
 		for userID, update := range statsQueue {
 			log.
@@ -573,7 +574,7 @@ func (a *Manager) resolvePerms(base, perm Permission) error {
 // read/write access to a topic. The parameter topicPattern may include wildcards (*). The ACL entry
 // owner may either be a user (username), or the system (empty).
 func (a *Manager) AllowAccess(username string, topicPattern string, permission Permission) error {
-	return execTx(a.db, func(tx *sql.Tx) error {
+	return db.ExecTx(a.db, func(tx *sql.Tx) error {
 		return a.allowAccessTx(tx, username, topicPattern, permission, false)
 	})
 }
@@ -591,7 +592,7 @@ func (a *Manager) allowAccessTx(tx *sql.Tx, username string, topicPattern string
 // ResetAccess removes an access control list entry for a specific username/topic, or (if topic is
 // empty) for an entire user. The parameter topicPattern may include wildcards (*).
 func (a *Manager) ResetAccess(username string, topicPattern string) error {
-	return execTx(a.db, func(tx *sql.Tx) error {
+	return db.ExecTx(a.db, func(tx *sql.Tx) error {
 		return a.resetAccessTx(tx, username, topicPattern)
 	})
 }
@@ -715,7 +716,7 @@ func (a *Manager) AddReservation(username string, topic string, everyone Permiss
 	if !AllowedUsername(username) || username == Everyone || !AllowedTopic(topic) {
 		return ErrInvalidArgument
 	}
-	return execTx(a.db, func(tx *sql.Tx) error {
+	return db.ExecTx(a.db, func(tx *sql.Tx) error {
 		if err := a.addReservationAccessTx(tx, username, topic, true, true, username); err != nil {
 			return err
 		}
@@ -735,7 +736,7 @@ func (a *Manager) RemoveReservations(username string, topics ...string) error {
 			return ErrInvalidArgument
 		}
 	}
-	return execTx(a.db, func(tx *sql.Tx) error {
+	return db.ExecTx(a.db, func(tx *sql.Tx) error {
 		for _, topic := range topics {
 			if err := a.resetTopicAccessTx(tx, username, topic); err != nil {
 				return err
@@ -874,7 +875,7 @@ func (a *Manager) resetTopicAccessTx(tx *sql.Tx, username, topicPattern string)
 // after a fixed duration unless ChangeToken is called. This function also prunes tokens for the
 // given user, if there are too many of them.
 func (a *Manager) CreateToken(userID, label string, expires time.Time, origin netip.Addr, provisioned bool) (*Token, error) {
-	return queryTx(a.db, func(tx *sql.Tx) (*Token, error) {
+	return db.QueryTx(a.db, func(tx *sql.Tx) (*Token, error) {
 		return a.createTokenTx(tx, userID, GenerateToken(), label, time.Now(), origin, expires, tokenMaxCount, provisioned)
 	})
 }
@@ -1033,7 +1034,7 @@ func (a *Manager) writeTokenUpdateQueue() error {
 	a.tokenQueue = make(map[string]*TokenUpdate)
 	a.mu.Unlock()
 
-	return execTx(a.db, func(tx *sql.Tx) error {
+	return db.ExecTx(a.db, func(tx *sql.Tx) error {
 		log.Tag(tag).Debug("Writing token update queue for %d token(s)", len(tokenQueue))
 		for tokenID, update := range tokenQueue {
 			log.Tag(tag).Trace("Updating token %s with last access time %v", tokenID, update.LastAccess.Unix())
@@ -1254,7 +1255,7 @@ func (a *Manager) maybeProvisionUsersAccessAndTokens() error {
 	if err != nil {
 		return err
 	}
-	return execTx(a.db, func(tx *sql.Tx) error {
+	return db.ExecTx(a.db, func(tx *sql.Tx) error {
 		if err := a.maybeProvisionUsers(tx, provisionUsernames, existingUsers); err != nil {
 			return fmt.Errorf("failed to provision users: %v", err)
 		}
diff --git a/user/util.go b/user/util.go
index 6354464d..16f6cc09 100644
--- a/user/util.go
+++ b/user/util.go
@@ -113,35 +113,3 @@ func escapeUnderscore(s string) string {
 func unescapeUnderscore(s string) string {
 	return strings.ReplaceAll(s, "\\_", "_")
 }
-
-// execTx executes a function in a transaction. If the function returns an error, the transaction is rolled back.
-func execTx(db *sql.DB, f func(tx *sql.Tx) error) error {
-	tx, err := db.Begin()
-	if err != nil {
-		return err
-	}
-	defer tx.Rollback()
-	if err := f(tx); err != nil {
-		return err
-	}
-	return tx.Commit()
-}
-
-// queryTx executes a function in a transaction and returns the result. If the function
-// returns an error, the transaction is rolled back.
-func queryTx[T any](db *sql.DB, f func(tx *sql.Tx) (T, error)) (T, error) {
-	tx, err := db.Begin()
-	if err != nil {
-		var zero T
-		return zero, err
-	}
-	defer tx.Rollback()
-	t, err := f(tx)
-	if err != nil {
-		return t, err
-	}
-	if err := tx.Commit(); err != nil {
-		return t, err
-	}
-	return t, nil
-}
diff --git a/webpush/store.go b/webpush/store.go
index 20ff19cc..ab5c517b 100644
--- a/webpush/store.go
+++ b/webpush/store.go
@@ -6,6 +6,7 @@ import (
 	"net/netip"
 	"time"
 
+	"heckel.io/ntfy/v2/db"
 	"heckel.io/ntfy/v2/util"
 )
 
@@ -46,41 +47,38 @@ type queries struct {
 
 // UpsertSubscription adds or updates Web Push subscriptions for the given topics and user ID.
 func (s *Store) UpsertSubscription(endpoint string, auth, p256dh, userID string, subscriberIP netip.Addr, topics []string) error {
-	tx, err := s.db.Begin()
-	if err != nil {
-		return err
-	}
-	defer tx.Rollback()
-	// Read number of subscriptions for subscriber IP address
-	var subscriptionCount int
-	if err := tx.QueryRow(s.queries.selectSubscriptionCountBySubscriberIP, subscriberIP.String()).Scan(&subscriptionCount); err != nil {
-		return err
-	}
-	// Read existing subscription ID for endpoint (or create new ID)
-	var subscriptionID string
-	if err := tx.QueryRow(s.queries.selectSubscriptionIDByEndpoint, endpoint).Scan(&subscriptionID); errors.Is(err, sql.ErrNoRows) {
-		if subscriptionCount >= subscriptionEndpointLimitPerSubscriberIP {
-			return ErrWebPushTooManySubscriptions
-		}
-		subscriptionID = util.RandomStringPrefix(subscriptionIDPrefix, subscriptionIDLength)
-	} else if err != nil {
-		return err
-	}
-	// Insert or update subscription
-	updatedAt, warnedAt := time.Now().Unix(), 0
-	if _, err := tx.Exec(s.queries.upsertSubscription, subscriptionID, endpoint, auth, p256dh, userID, subscriberIP.String(), updatedAt, warnedAt); err != nil {
-		return err
-	}
-	// Replace all subscription topics
-	if _, err := tx.Exec(s.queries.deleteSubscriptionTopicAll, subscriptionID); err != nil {
-		return err
-	}
-	for _, topic := range topics {
-		if _, err = tx.Exec(s.queries.insertSubscriptionTopic, subscriptionID, topic); err != nil {
+	return db.ExecTx(s.db, func(tx *sql.Tx) error {
+		// Read number of subscriptions for subscriber IP address
+		var subscriptionCount int
+		if err := tx.QueryRow(s.queries.selectSubscriptionCountBySubscriberIP, subscriberIP.String()).Scan(&subscriptionCount); err != nil {
 			return err
 		}
-	}
-	return tx.Commit()
+		// Read existing subscription ID for endpoint (or create new ID)
+		var subscriptionID string
+		if err := tx.QueryRow(s.queries.selectSubscriptionIDByEndpoint, endpoint).Scan(&subscriptionID); errors.Is(err, sql.ErrNoRows) {
+			if subscriptionCount >= subscriptionEndpointLimitPerSubscriberIP {
+				return ErrWebPushTooManySubscriptions
+			}
+			subscriptionID = util.RandomStringPrefix(subscriptionIDPrefix, subscriptionIDLength)
+		} else if err != nil {
+			return err
+		}
+		// Insert or update subscription
+		updatedAt, warnedAt := time.Now().Unix(), 0
+		if _, err := tx.Exec(s.queries.upsertSubscription, subscriptionID, endpoint, auth, p256dh, userID, subscriberIP.String(), updatedAt, warnedAt); err != nil {
+			return err
+		}
+		// Replace all subscription topics
+		if _, err := tx.Exec(s.queries.deleteSubscriptionTopicAll, subscriptionID); err != nil {
+			return err
+		}
+		for _, topic := range topics {
+			if _, err := tx.Exec(s.queries.insertSubscriptionTopic, subscriptionID, topic); err != nil {
+				return err
+			}
+		}
+		return nil
+	})
 }
 
 // SubscriptionsForTopic returns all subscriptions for the given topic.
@@ -105,17 +103,14 @@ func (s *Store) SubscriptionsExpiring(warnAfter time.Duration) ([]*Subscription,
 
 // MarkExpiryWarningSent marks the given subscriptions as having received a warning about expiring soon.
 func (s *Store) MarkExpiryWarningSent(subscriptions []*Subscription) error {
-	tx, err := s.db.Begin()
-	if err != nil {
-		return err
-	}
-	defer tx.Rollback()
-	for _, subscription := range subscriptions {
-		if _, err := tx.Exec(s.queries.updateSubscriptionWarningSent, time.Now().Unix(), subscription.ID); err != nil {
-			return err
+	return db.ExecTx(s.db, func(tx *sql.Tx) error {
+		for _, subscription := range subscriptions {
+			if _, err := tx.Exec(s.queries.updateSubscriptionWarningSent, time.Now().Unix(), subscription.ID); err != nil {
+				return err
+			}
 		}
-	}
-	return tx.Commit()
+		return nil
+	})
 }
 
 // RemoveSubscriptionsByEndpoint removes the subscription for the given endpoint.
diff --git a/webpush/store_postgres.go b/webpush/store_postgres.go
index d9c61470..ec541d37 100644
--- a/webpush/store_postgres.go
+++ b/webpush/store_postgres.go
@@ -3,6 +3,8 @@ package webpush
 import (
 	"database/sql"
 	"fmt"
+
+	"heckel.io/ntfy/v2/db"
 )
 
 const (
@@ -107,17 +109,14 @@ func setupPostgres(db *sql.DB) error {
 	return nil
 }
 
-func setupNewPostgres(db *sql.DB) error {
-	tx, err := db.Begin()
-	if err != nil {
-		return err
-	}
-	defer tx.Rollback()
-	if _, err := tx.Exec(postgresCreateTablesQuery); err != nil {
-		return err
-	}
-	if _, err := tx.Exec(postgresInsertSchemaVersionQuery, pgCurrentSchemaVersion); err != nil {
-		return err
-	}
-	return tx.Commit()
+func setupNewPostgres(sqlDB *sql.DB) error {
+	return db.ExecTx(sqlDB, func(tx *sql.Tx) error {
+		if _, err := tx.Exec(postgresCreateTablesQuery); err != nil {
+			return err
+		}
+		if _, err := tx.Exec(postgresInsertSchemaVersionQuery, pgCurrentSchemaVersion); err != nil {
+			return err
+		}
+		return nil
+	})
 }
diff --git a/webpush/store_sqlite.go b/webpush/store_sqlite.go
index d41e1c8d..90ca14a8 100644
--- a/webpush/store_sqlite.go
+++ b/webpush/store_sqlite.go
@@ -5,6 +5,8 @@ import (
 	"fmt"
 
 	_ "github.com/mattn/go-sqlite3" // SQLite driver
+
+	"heckel.io/ntfy/v2/db"
 )
 
 const (
@@ -119,19 +121,16 @@ func setupSQLite(db *sql.DB) error {
 	return nil
 }
 
-func setupNewSQLite(db *sql.DB) error {
-	tx, err := db.Begin()
-	if err != nil {
-		return err
-	}
-	defer tx.Rollback()
-	if _, err := tx.Exec(sqliteCreateTablesQuery); err != nil {
-		return err
-	}
-	if _, err := tx.Exec(sqliteInsertSchemaVersionQuery, sqliteCurrentSchemaVersion); err != nil {
-		return err
-	}
-	return tx.Commit()
+func setupNewSQLite(sqlDB *sql.DB) error {
+	return db.ExecTx(sqlDB, func(tx *sql.Tx) error {
+		if _, err := tx.Exec(sqliteCreateTablesQuery); err != nil {
+			return err
+		}
+		if _, err := tx.Exec(sqliteInsertSchemaVersionQuery, sqliteCurrentSchemaVersion); err != nil {
+			return err
+		}
+		return nil
+	})
 }
 
 func runSQLiteStartupQueries(db *sql.DB, startupQueries string) error {