Derp

go.mod

@@ -32,6 +32,7 @@ require github.com/pkg/errors v0.9.1 // indirect
 require (
 	firebase.google.com/go/v4 v4.18.0
 	github.com/SherClockHolmes/webpush-go v1.4.0
+	github.com/jackc/pgx/v5 v5.8.0
 	github.com/microcosm-cc/bluemonday v1.0.27
 	github.com/prometheus/client_golang v1.23.2
 	github.com/stripe/stripe-go/v74 v74.30.0
@@ -72,6 +73,9 @@ require (
 	github.com/googleapis/enterprise-certificate-proxy v0.3.7 // indirect
 	github.com/googleapis/gax-go/v2 v2.16.0 // indirect
 	github.com/gorilla/css v1.0.1 // indirect
+	github.com/jackc/pgpassfile v1.0.0 // indirect
+	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
+	github.com/jackc/puddle/v2 v2.2.2 // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/planetscale/vtprotobuf v0.6.1-0.20240319094008-0393e58bdf10 // indirect
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect

go.sum

@@ -104,6 +104,14 @@ github.com/gorilla/css v1.0.1 h1:ntNaBIghp6JmvWnxbZKANoLyuXTPZ4cAMlo6RyhlbO8=
 github.com/gorilla/css v1.0.1/go.mod h1:BvnYkspnSzMmwRK+b8/xgNPLiIuNZr6vbZBTPQ2A3b0=
 github.com/gorilla/websocket v1.5.3 h1:saDtZ6Pbx/0u+bgYQ3q96pZgCzfhKXGPqt7kZ72aNNg=
 github.com/gorilla/websocket v1.5.3/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
+github.com/jackc/pgpassfile v1.0.0 h1:/6Hmqy13Ss2zCq62VdNG8tM1wchn8zjSGOBJ6icpsIM=
+github.com/jackc/pgpassfile v1.0.0/go.mod h1:CEx0iS5ambNFdcRtxPj5JhEz+xB6uRky5eyVu/W2HEg=
+github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 h1:iCEnooe7UlwOQYpKFhBabPMi4aNAfoODPEFNiAnClxo=
+github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761/go.mod h1:5TJZWKEWniPve33vlWYSoGYefn3gLQRzjfDlhSJ9ZKM=
+github.com/jackc/pgx/v5 v5.8.0 h1:TYPDoleBBme0xGSAX3/+NujXXtpZn9HBONkQC7IEZSo=
+github.com/jackc/pgx/v5 v5.8.0/go.mod h1:QVeDInX2m9VyzvNeiCJVjCkNFqzsNb43204HshNSZKw=
+github.com/jackc/puddle/v2 v2.2.2 h1:PR8nw+E/1w0GLuRFSmiioY6UooMp6KJv0/61nB7icHo=
+github.com/jackc/puddle/v2 v2.2.2/go.mod h1:vriiEXHvEE654aYKXXjOvZM39qJ0q+azkZFrfEOc3H4=
 github.com/klauspost/compress v1.18.0 h1:c/Cqfb0r+Yi+JtIEq73FWXVkRonBlf0CRNYc8Zttxdo=
 github.com/klauspost/compress v1.18.0/go.mod h1:2Pp+KzxcywXVXMr50+X0Q/Lsb43OQHYWRCY2AiWywWQ=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
@@ -144,6 +152,7 @@ github.com/spiffe/go-spiffe/v2 v2.6.0/go.mod h1:gm2SeUoMZEtpnzPNs2Csc0D/gX33k1xI
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.5.2 h1:xuMeJ0Sdp5ZMRXx/aWO6RZxdr3beISkG5/G/aIRr3pY=
 github.com/stretchr/objx v0.5.2/go.mod h1:FRsXN1f5AsAjCGJKqEizvkpNtU+EGNCLh3NxZ/8L+MA=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
 github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=

server/message_cache.go

@@ -4,351 +4,89 @@ import (
 	"database/sql"
 	"encoding/json"
 	"errors"
-	"fmt"
 	"net/netip"
-	"path/filepath"
 	"strings"
 	"sync"
 	"time"
 
-	_ "github.com/mattn/go-sqlite3" // SQLite driver
 	"heckel.io/ntfy/v2/log"
 	"heckel.io/ntfy/v2/util"
 )
 
-var (
-	errUnexpectedMessageType = errors.New("unexpected message type")
-	errMessageNotFound       = errors.New("message not found")
-	errNoRows                = errors.New("no rows found")
-)
-
-// Messages cache
-const (
-	createMessagesTableQuery = `
-		BEGIN;
-		CREATE TABLE IF NOT EXISTS messages (
-			id INTEGER PRIMARY KEY AUTOINCREMENT,
-			mid TEXT NOT NULL,
-			time INT NOT NULL,
-			expires INT NOT NULL,
-			topic TEXT NOT NULL,
-			message TEXT NOT NULL,
-			title TEXT NOT NULL,
-			priority INT NOT NULL,
-			tags TEXT NOT NULL,
-			click TEXT NOT NULL,
-			icon TEXT NOT NULL,
-			actions TEXT NOT NULL,
-			attachment_name TEXT NOT NULL,
-			attachment_type TEXT NOT NULL,
-			attachment_size INT NOT NULL,
-			attachment_expires INT NOT NULL,
-			attachment_url TEXT NOT NULL,
-			attachment_deleted INT NOT NULL,
-			sender TEXT NOT NULL,
-			user TEXT NOT NULL,
-			content_type TEXT NOT NULL,
-			encoding TEXT NOT NULL,
-			published INT NOT NULL
-		);
-		CREATE INDEX IF NOT EXISTS idx_mid ON messages (mid);
-		CREATE INDEX IF NOT EXISTS idx_time ON messages (time);
-		CREATE INDEX IF NOT EXISTS idx_topic ON messages (topic);
-		CREATE INDEX IF NOT EXISTS idx_expires ON messages (expires);
-		CREATE INDEX IF NOT EXISTS idx_sender ON messages (sender);
-		CREATE INDEX IF NOT EXISTS idx_user ON messages (user);
-		CREATE INDEX IF NOT EXISTS idx_attachment_expires ON messages (attachment_expires);
-		CREATE TABLE IF NOT EXISTS stats (
-			key TEXT PRIMARY KEY,
-			value INT
-		);
-		INSERT INTO stats (key, value) VALUES ('messages', 0);
-		COMMIT;
-	`
-	insertMessageQuery = `
-		INSERT INTO messages (mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, attachment_deleted, sender, user, content_type, encoding, published)
-		VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
-	`
-	deleteMessageQuery                = `DELETE FROM messages WHERE mid = ?`
-	updateMessagesForTopicExpiryQuery = `UPDATE messages SET expires = ? WHERE topic = ?`
-	selectRowIDFromMessageID          = `SELECT id FROM messages WHERE mid = ?` // Do not include topic, see #336 and TestServer_PollSinceID_MultipleTopics
-	selectMessagesByIDQuery           = `
-		SELECT mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, sender, user, content_type, encoding
-		FROM messages
-		WHERE mid = ?
-	`
-	selectMessagesSinceTimeQuery = `
-		SELECT mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, sender, user, content_type, encoding
-		FROM messages
-		WHERE topic = ? AND time >= ? AND published = 1
-		ORDER BY time, id
-	`
-	selectMessagesSinceTimeIncludeScheduledQuery = `
-		SELECT mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, sender, user, content_type, encoding
-		FROM messages
-		WHERE topic = ? AND time >= ?
-		ORDER BY time, id
-	`
-	selectMessagesSinceIDQuery = `
-		SELECT mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, sender, user, content_type, encoding
-		FROM messages
-		WHERE topic = ? AND id > ? AND published = 1 
-		ORDER BY time, id
-	`
-	selectMessagesSinceIDIncludeScheduledQuery = `
-		SELECT mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, sender, user, content_type, encoding
-		FROM messages
-		WHERE topic = ? AND (id > ? OR published = 0)
-		ORDER BY time, id
-	`
-	selectMessagesLatestQuery = `
-		SELECT mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, sender, user, content_type, encoding
-		FROM messages
-		WHERE topic = ? AND published = 1
-		ORDER BY time DESC, id DESC
-		LIMIT 1
-	`
-	selectMessagesDueQuery = `
-		SELECT mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, sender, user, content_type, encoding
-		FROM messages
-		WHERE time <= ? AND published = 0
-		ORDER BY time, id
-	`
-	selectMessagesExpiredQuery      = `SELECT mid FROM messages WHERE expires <= ? AND published = 1`
-	updateMessagePublishedQuery     = `UPDATE messages SET published = 1 WHERE mid = ?`
-	selectMessagesCountQuery        = `SELECT COUNT(*) FROM messages`
-	selectMessageCountPerTopicQuery = `SELECT topic, COUNT(*) FROM messages GROUP BY topic`
-	selectTopicsQuery               = `SELECT topic FROM messages GROUP BY topic`
-
-	updateAttachmentDeleted            = `UPDATE messages SET attachment_deleted = 1 WHERE mid = ?`
-	selectAttachmentsExpiredQuery      = `SELECT mid FROM messages WHERE attachment_expires > 0 AND attachment_expires <= ? AND attachment_deleted = 0`
-	selectAttachmentsSizeBySenderQuery = `SELECT IFNULL(SUM(attachment_size), 0) FROM messages WHERE user = '' AND sender = ? AND attachment_expires >= ?`
-	selectAttachmentsSizeByUserIDQuery = `SELECT IFNULL(SUM(attachment_size), 0) FROM messages WHERE user = ? AND attachment_expires >= ?`
-
-	selectStatsQuery = `SELECT value FROM stats WHERE key = 'messages'`
-	updateStatsQuery = `UPDATE stats SET value = ? WHERE key = 'messages'`
-)
-
-// Schema management queries
-const (
-	currentSchemaVersion          = 13
-	createSchemaVersionTableQuery = `
-		CREATE TABLE IF NOT EXISTS schemaVersion (
-			id INT PRIMARY KEY,
-			version INT NOT NULL
-		);
-	`
-	insertSchemaVersion      = `INSERT INTO schemaVersion VALUES (1, ?)`
-	updateSchemaVersion      = `UPDATE schemaVersion SET version = ? WHERE id = 1`
-	selectSchemaVersionQuery = `SELECT version FROM schemaVersion WHERE id = 1`
-
-	// 0 -> 1
-	migrate0To1AlterMessagesTableQuery = `
-		BEGIN;
-		ALTER TABLE messages ADD COLUMN title TEXT NOT NULL DEFAULT('');
-		ALTER TABLE messages ADD COLUMN priority INT NOT NULL DEFAULT(0);
-		ALTER TABLE messages ADD COLUMN tags TEXT NOT NULL DEFAULT('');
-		COMMIT;
-	`
-
-	// 1 -> 2
-	migrate1To2AlterMessagesTableQuery = `
-		ALTER TABLE messages ADD COLUMN published INT NOT NULL DEFAULT(1);
-	`
-
-	// 2 -> 3
-	migrate2To3AlterMessagesTableQuery = `
-		BEGIN;
-		ALTER TABLE messages ADD COLUMN click TEXT NOT NULL DEFAULT('');
-		ALTER TABLE messages ADD COLUMN attachment_name TEXT NOT NULL DEFAULT('');
-		ALTER TABLE messages ADD COLUMN attachment_type TEXT NOT NULL DEFAULT('');
-		ALTER TABLE messages ADD COLUMN attachment_size INT NOT NULL DEFAULT('0');
-		ALTER TABLE messages ADD COLUMN attachment_expires INT NOT NULL DEFAULT('0');
-		ALTER TABLE messages ADD COLUMN attachment_owner TEXT NOT NULL DEFAULT('');
-		ALTER TABLE messages ADD COLUMN attachment_url TEXT NOT NULL DEFAULT('');
-		COMMIT;
-	`
-	// 3 -> 4
-	migrate3To4AlterMessagesTableQuery = `
-		ALTER TABLE messages ADD COLUMN encoding TEXT NOT NULL DEFAULT('');
-	`
-
-	// 4 -> 5
-	migrate4To5AlterMessagesTableQuery = `
-		BEGIN;
-		CREATE TABLE IF NOT EXISTS messages_new (
-			id INTEGER PRIMARY KEY AUTOINCREMENT,
-			mid TEXT NOT NULL,
-			time INT NOT NULL,
-			topic TEXT NOT NULL,
-			message TEXT NOT NULL,
-			title TEXT NOT NULL,
-			priority INT NOT NULL,
-			tags TEXT NOT NULL,
-			click TEXT NOT NULL,
-			attachment_name TEXT NOT NULL,
-			attachment_type TEXT NOT NULL,
-			attachment_size INT NOT NULL,
-			attachment_expires INT NOT NULL,
-			attachment_url TEXT NOT NULL,
-			attachment_owner TEXT NOT NULL,
-			encoding TEXT NOT NULL,
-			published INT NOT NULL
-		);
-		CREATE INDEX IF NOT EXISTS idx_mid ON messages_new (mid);
-		CREATE INDEX IF NOT EXISTS idx_topic ON messages_new (topic);
-		INSERT 
-			INTO messages_new (
-				mid, time, topic, message, title, priority, tags, click, attachment_name, attachment_type, 
-				attachment_size, attachment_expires, attachment_url, attachment_owner, encoding, published)
-			SELECT
-				id, time, topic, message, title, priority, tags, click, attachment_name, attachment_type, 
-				attachment_size, attachment_expires, attachment_url, attachment_owner, encoding, published
-			FROM messages;
-		DROP TABLE messages;
-		ALTER TABLE messages_new RENAME TO messages;
-		COMMIT;
-	`
-
-	// 5 -> 6
-	migrate5To6AlterMessagesTableQuery = `
-		ALTER TABLE messages ADD COLUMN actions TEXT NOT NULL DEFAULT('');
-	`
-
-	// 6 -> 7
-	migrate6To7AlterMessagesTableQuery = `
-		ALTER TABLE messages RENAME COLUMN attachment_owner TO sender;
-	`
-
-	// 7 -> 8
-	migrate7To8AlterMessagesTableQuery = `
-		ALTER TABLE messages ADD COLUMN icon TEXT NOT NULL DEFAULT('');
-	`
-
-	// 8 -> 9
-	migrate8To9AlterMessagesTableQuery = `
-		CREATE INDEX IF NOT EXISTS idx_time ON messages (time);	
-	`
-
-	// 9 -> 10
-	migrate9To10AlterMessagesTableQuery = `
-		ALTER TABLE messages ADD COLUMN user TEXT NOT NULL DEFAULT('');
-		ALTER TABLE messages ADD COLUMN attachment_deleted INT NOT NULL DEFAULT('0');
-		ALTER TABLE messages ADD COLUMN expires INT NOT NULL DEFAULT('0');
-		CREATE INDEX IF NOT EXISTS idx_expires ON messages (expires);
-		CREATE INDEX IF NOT EXISTS idx_sender ON messages (sender);
-		CREATE INDEX IF NOT EXISTS idx_user ON messages (user);
-		CREATE INDEX IF NOT EXISTS idx_attachment_expires ON messages (attachment_expires);
-	`
-	migrate9To10UpdateMessageExpiryQuery = `UPDATE messages SET expires = time + ?`
-
-	// 10 -> 11
-	migrate10To11AlterMessagesTableQuery = `
-		CREATE TABLE IF NOT EXISTS stats (
-			key TEXT PRIMARY KEY,
-			value INT
-		);
-		INSERT INTO stats (key, value) VALUES ('messages', 0);
-	`
-
-	// 11 -> 12
-	migrate11To12AlterMessagesTableQuery = `
-		ALTER TABLE messages ADD COLUMN content_type TEXT NOT NULL DEFAULT('');
-	`
-
-	// 12 -> 13
-	migrate12To13AlterMessagesTableQuery = `
-		CREATE INDEX IF NOT EXISTS idx_topic ON messages (topic);
-	`
-)
-
-var (
-	migrations = map[int]func(db *sql.DB, cacheDuration time.Duration) error{
-		0:  migrateFrom0,
-		1:  migrateFrom1,
-		2:  migrateFrom2,
-		3:  migrateFrom3,
-		4:  migrateFrom4,
-		5:  migrateFrom5,
-		6:  migrateFrom6,
-		7:  migrateFrom7,
-		8:  migrateFrom8,
-		9:  migrateFrom9,
-		10: migrateFrom10,
-		11: migrateFrom11,
-		12: migrateFrom12,
-	}
-)
-
-type messageCache struct {
-	db    *sql.DB
-	queue *util.BatchingQueue[*message]
-	nop   bool
-	mu    sync.Mutex
+// MessageCache is the interface for message storage backends
+type MessageCache interface {
+	AddMessage(m *message) error
+	AddMessages(ms []*message) error
+	Messages(topic string, since sinceMarker, scheduled bool) ([]*message, error)
+	MessagesDue() ([]*message, error)
+	MessagesExpired() ([]string, error)
+	Message(id string) (*message, error)
+	MarkPublished(m *message) error
+	MessageCounts() (map[string]int, error)
+	Topics() (map[string]*topic, error)
+	DeleteMessages(ids ...string) error
+	ExpireMessages(topics ...string) error
+	AttachmentsExpired() ([]string, error)
+	MarkAttachmentsDeleted(ids ...string) error
+	AttachmentBytesUsedBySender(sender string) (int64, error)
+	AttachmentBytesUsedByUser(userID string) (int64, error)
+	UpdateStats(messages int64) error
+	Stats() (messages int64, err error)
+	DB() *sql.DB
+	Close() error
 }
 
-// newSqliteCache creates a SQLite file-backed cache
-func newSqliteCache(filename, startupQueries string, cacheDuration time.Duration, batchSize int, batchTimeout time.Duration, nop bool) (*messageCache, error) {
-	// Check the parent directory of the database file (makes for friendly error messages)
-	parentDir := filepath.Dir(filename)
-	if !util.FileExists(parentDir) {
-		return nil, fmt.Errorf("cache database directory %s does not exist or is not accessible", parentDir)
-	}
-	// Open database
-	db, err := sql.Open("sqlite3", filename)
-	if err != nil {
-		return nil, err
-	}
-	if err := setupMessagesDB(db, startupQueries, cacheDuration); err != nil {
-		return nil, err
-	}
-	var queue *util.BatchingQueue[*message]
-	if batchSize > 0 || batchTimeout > 0 {
-		queue = util.NewBatchingQueue[*message](batchSize, batchTimeout)
-	}
-	cache := &messageCache{
-		db:    db,
-		queue: queue,
-		nop:   nop,
-	}
-	go cache.processMessageBatches()
-	return cache, nil
+// commonMessageCache contains shared logic for all message cache implementations
+type commonMessageCache struct {
+	db      *sql.DB
+	queue   *util.BatchingQueue[*message]
+	queries *messageCacheQueries
+	nop     bool       // If true, cache ignores all messages
+	mu      sync.Mutex // Lock for concurrent access
 }
 
-// newMemCache creates an in-memory cache
-func newMemCache() (*messageCache, error) {
-	return newSqliteCache(createMemoryFilename(), "", 0, 0, 0, false)
-}
+var _ MessageCache = (*commonMessageCache)(nil)
 
-// newNopCache creates an in-memory cache that discards all messages;
-// it is always empty and can be used if caching is entirely disabled
-func newNopCache() (*messageCache, error) {
-	return newSqliteCache(createMemoryFilename(), "", 0, 0, 0, true)
-}
+// messageCacheQueries holds database-specific SQL queries
+type messageCacheQueries struct {
+	insertMessage                           string
+	deleteMessage                           string
+	updateMessagesForTopicExpiry            string
+	selectRowIDFromMessageID                string // Do not include topic, see #336 and TestServer_PollSinceID_MultipleTopics
+	selectMessagesByID                      string
+	selectMessagesSinceTime                 string
+	selectMessagesSinceTimeIncludeScheduled string
+	selectMessagesSinceID                   string
+	selectMessagesSinceIDIncludeScheduled   string
+	selectMessagesLatest                    string
+	selectMessagesDue                       string
+	selectMessagesExpired                   string
+	updateMessagePublished                  string
+	selectMessageCountPerTopic              string
+	selectTopics                            string
 
-// createMemoryFilename creates a unique memory filename to use for the SQLite backend.
-// From mattn/go-sqlite3: "Each connection to ":memory:" opens a brand new in-memory
-// sql database, so if the stdlib's sql engine happens to open another connection and
-// you've only specified ":memory:", that connection will see a brand new database.
-// A workaround is to use "file::memory:?cache=shared" (or "file:foobar?mode=memory&cache=shared").
-// Every connection to this string will point to the same in-memory database."
-func createMemoryFilename() string {
-	return fmt.Sprintf("file:%s?mode=memory&cache=shared", util.RandomString(10))
+	updateAttachmentDeleted       string
+	selectAttachmentsExpired      string
+	selectAttachmentsSizeBySender string
+	selectAttachmentsSizeByUserID string
+
+	selectStats string
+	updateStats string
 }
 
 // AddMessage stores a message to the message cache synchronously, or queues it to be stored at a later date asyncronously.
 // The message is queued only if "batchSize" or "batchTimeout" are passed to the constructor.
-func (c *messageCache) AddMessage(m *message) error {
+func (c *commonMessageCache) AddMessage(m *message) error {
 	if c.queue != nil {
 		c.queue.Enqueue(m)
 		return nil
 	}
-	return c.addMessages([]*message{m})
+	return c.AddMessages([]*message{m})
 }
 
-// addMessages synchronously stores a match of messages. If the database is locked, the transaction waits until
-// SQLite's busy_timeout is exceeded before erroring out.
-func (c *messageCache) addMessages(ms []*message) error {
+// AddMessages synchronously stores a batch of messages. If the database is locked, the transaction waits until
+// the timeout is exceeded before erroring out.
+func (c *commonMessageCache) AddMessages(ms []*message) error {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 	if c.nop {
@@ -363,7 +101,7 @@ func (c *messageCache) addMessages(ms []*message) error {
 		return err
 	}
 	defer tx.Rollback()
-	stmt, err := tx.Prepare(insertMessageQuery)
+	stmt, err := tx.Prepare(c.queries.insertMessage)
 	if err != nil {
 		return err
 	}
@@ -375,7 +113,8 @@ func (c *messageCache) addMessages(ms []*message) error {
 		published := m.Time <= time.Now().Unix()
 		tags := strings.Join(m.Tags, ",")
 		var attachmentName, attachmentType, attachmentURL string
-		var attachmentSize, attachmentExpires, attachmentDeleted int64
+		var attachmentSize, attachmentExpires int64
+		var attachmentDeleted bool
 		if m.Attachment != nil {
 			attachmentName = m.Attachment.Name
 			attachmentType = m.Attachment.Type
@@ -412,7 +151,7 @@ func (c *messageCache) addMessages(ms []*message) error {
 			attachmentSize,
 			attachmentExpires,
 			attachmentURL,
-			attachmentDeleted, // Always zero
+			attachmentDeleted, // Always false
 			sender,
 			m.User,
 			m.ContentType,
@@ -431,7 +170,7 @@ func (c *messageCache) addMessages(ms []*message) error {
 	return nil
 }
 
-func (c *messageCache) Messages(topic string, since sinceMarker, scheduled bool) ([]*message, error) {
+func (c *commonMessageCache) Messages(topic string, since sinceMarker, scheduled bool) ([]*message, error) {
 	if since.IsNone() {
 		return make([]*message, 0), nil
 	} else if since.IsLatest() {
@@ -442,13 +181,21 @@ func (c *messageCache) Messages(topic string, since sinceMarker, scheduled bool)
 	return c.messagesSinceTime(topic, since, scheduled)
 }
 
-func (c *messageCache) messagesSinceTime(topic string, since sinceMarker, scheduled bool) ([]*message, error) {
+func (c *commonMessageCache) messagesLatest(topic string) ([]*message, error) {
+	rows, err := c.db.Query(c.queries.selectMessagesLatest, topic)
+	if err != nil {
+		return nil, err
+	}
+	return readMessages(rows)
+}
+
+func (c *commonMessageCache) messagesSinceTime(topic string, since sinceMarker, scheduled bool) ([]*message, error) {
 	var rows *sql.Rows
 	var err error
 	if scheduled {
-		rows, err = c.db.Query(selectMessagesSinceTimeIncludeScheduledQuery, topic, since.Time().Unix())
+		rows, err = c.db.Query(c.queries.selectMessagesSinceTimeIncludeScheduled, topic, since.Time().Unix())
 	} else {
-		rows, err = c.db.Query(selectMessagesSinceTimeQuery, topic, since.Time().Unix())
+		rows, err = c.db.Query(c.queries.selectMessagesSinceTime, topic, since.Time().Unix())
 	}
 	if err != nil {
 		return nil, err
@@ -456,8 +203,8 @@ func (c *messageCache) messagesSinceTime(topic string, since sinceMarker, schedu
 	return readMessages(rows)
 }
 
-func (c *messageCache) messagesSinceID(topic string, since sinceMarker, scheduled bool) ([]*message, error) {
-	idrows, err := c.db.Query(selectRowIDFromMessageID, since.ID())
+func (c *commonMessageCache) messagesSinceID(topic string, since sinceMarker, scheduled bool) ([]*message, error) {
+	idrows, err := c.db.Query(c.queries.selectRowIDFromMessageID, since.ID())
 	if err != nil {
 		return nil, err
 	}
@@ -472,9 +219,9 @@ func (c *messageCache) messagesSinceID(topic string, since sinceMarker, schedule
 	idrows.Close()
 	var rows *sql.Rows
 	if scheduled {
-		rows, err = c.db.Query(selectMessagesSinceIDIncludeScheduledQuery, topic, rowID)
+		rows, err = c.db.Query(c.queries.selectMessagesSinceIDIncludeScheduled, topic, rowID)
 	} else {
-		rows, err = c.db.Query(selectMessagesSinceIDQuery, topic, rowID)
+		rows, err = c.db.Query(c.queries.selectMessagesSinceID, topic, rowID)
 	}
 	if err != nil {
 		return nil, err
@@ -482,25 +229,17 @@ func (c *messageCache) messagesSinceID(topic string, since sinceMarker, schedule
 	return readMessages(rows)
 }
 
-func (c *messageCache) messagesLatest(topic string) ([]*message, error) {
-	rows, err := c.db.Query(selectMessagesLatestQuery, topic)
+func (c *commonMessageCache) MessagesDue() ([]*message, error) {
+	rows, err := c.db.Query(c.queries.selectMessagesDue, time.Now().Unix())
 	if err != nil {
 		return nil, err
 	}
 	return readMessages(rows)
 }
 
-func (c *messageCache) MessagesDue() ([]*message, error) {
-	rows, err := c.db.Query(selectMessagesDueQuery, time.Now().Unix())
-	if err != nil {
-		return nil, err
-	}
-	return readMessages(rows)
-}
-
-// MessagesExpired returns a list of IDs for messages that have expires (should be deleted)
-func (c *messageCache) MessagesExpired() ([]string, error) {
-	rows, err := c.db.Query(selectMessagesExpiredQuery, time.Now().Unix())
+// MessagesExpired returns a list of IDs for messages that have expired (should be deleted)
+func (c *commonMessageCache) MessagesExpired() ([]string, error) {
+	rows, err := c.db.Query(c.queries.selectMessagesExpired, time.Now().Unix())
 	if err != nil {
 		return nil, err
 	}
@@ -519,27 +258,24 @@ func (c *messageCache) MessagesExpired() ([]string, error) {
 	return ids, nil
 }
 
-func (c *messageCache) Message(id string) (*message, error) {
-	rows, err := c.db.Query(selectMessagesByIDQuery, id)
+func (c *commonMessageCache) Message(id string) (*message, error) {
+	rows, err := c.db.Query(c.queries.selectMessagesByID, id)
 	if err != nil {
 		return nil, err
-	}
-	if !rows.Next() {
+	} else if !rows.Next() {
 		return nil, errMessageNotFound
 	}
 	defer rows.Close()
 	return readMessage(rows)
 }
 
-func (c *messageCache) MarkPublished(m *message) error {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	_, err := c.db.Exec(updateMessagePublishedQuery, m.ID)
+func (c *commonMessageCache) MarkPublished(m *message) error {
+	_, err := c.db.Exec(c.queries.updateMessagePublished, m.ID)
 	return err
 }
 
-func (c *messageCache) MessageCounts() (map[string]int, error) {
-	rows, err := c.db.Query(selectMessageCountPerTopicQuery)
+func (c *commonMessageCache) MessageCounts() (map[string]int, error) {
+	rows, err := c.db.Query(c.queries.selectMessageCountPerTopic)
 	if err != nil {
 		return nil, err
 	}
@@ -558,8 +294,8 @@ func (c *messageCache) MessageCounts() (map[string]int, error) {
 	return counts, nil
 }
 
-func (c *messageCache) Topics() (map[string]*topic, error) {
-	rows, err := c.db.Query(selectTopicsQuery)
+func (c *commonMessageCache) Topics() (map[string]*topic, error) {
+	rows, err := c.db.Query(c.queries.selectTopics)
 	if err != nil {
 		return nil, err
 	}
@@ -578,40 +314,36 @@ func (c *messageCache) Topics() (map[string]*topic, error) {
 	return topics, nil
 }
 
-func (c *messageCache) DeleteMessages(ids ...string) error {
-	c.mu.Lock()
-	defer c.mu.Unlock()
+func (c *commonMessageCache) DeleteMessages(ids ...string) error {
 	tx, err := c.db.Begin()
 	if err != nil {
 		return err
 	}
 	defer tx.Rollback()
 	for _, id := range ids {
-		if _, err := tx.Exec(deleteMessageQuery, id); err != nil {
+		if _, err := tx.Exec(c.queries.deleteMessage, id); err != nil {
 			return err
 		}
 	}
 	return tx.Commit()
 }
 
-func (c *messageCache) ExpireMessages(topics ...string) error {
-	c.mu.Lock()
-	defer c.mu.Unlock()
+func (c *commonMessageCache) ExpireMessages(topics ...string) error {
 	tx, err := c.db.Begin()
 	if err != nil {
 		return err
 	}
 	defer tx.Rollback()
 	for _, t := range topics {
-		if _, err := tx.Exec(updateMessagesForTopicExpiryQuery, time.Now().Unix()-1, t); err != nil {
+		if _, err := tx.Exec(c.queries.updateMessagesForTopicExpiry, time.Now().Unix()-1, t); err != nil {
 			return err
 		}
 	}
 	return tx.Commit()
 }
 
-func (c *messageCache) AttachmentsExpired() ([]string, error) {
-	rows, err := c.db.Query(selectAttachmentsExpiredQuery, time.Now().Unix())
+func (c *commonMessageCache) AttachmentsExpired() ([]string, error) {
+	rows, err := c.db.Query(c.queries.selectAttachmentsExpired, time.Now().Unix())
 	if err != nil {
 		return nil, err
 	}
@@ -630,39 +362,37 @@ func (c *messageCache) AttachmentsExpired() ([]string, error) {
 	return ids, nil
 }
 
-func (c *messageCache) MarkAttachmentsDeleted(ids ...string) error {
-	c.mu.Lock()
-	defer c.mu.Unlock()
+func (c *commonMessageCache) MarkAttachmentsDeleted(ids ...string) error {
 	tx, err := c.db.Begin()
 	if err != nil {
 		return err
 	}
 	defer tx.Rollback()
 	for _, id := range ids {
-		if _, err := tx.Exec(updateAttachmentDeleted, id); err != nil {
+		if _, err := tx.Exec(c.queries.updateAttachmentDeleted, id); err != nil {
 			return err
 		}
 	}
 	return tx.Commit()
 }
 
-func (c *messageCache) AttachmentBytesUsedBySender(sender string) (int64, error) {
-	rows, err := c.db.Query(selectAttachmentsSizeBySenderQuery, sender, time.Now().Unix())
+func (c *commonMessageCache) AttachmentBytesUsedBySender(sender string) (int64, error) {
+	rows, err := c.db.Query(c.queries.selectAttachmentsSizeBySender, sender, time.Now().Unix())
 	if err != nil {
 		return 0, err
 	}
 	return c.readAttachmentBytesUsed(rows)
 }
 
-func (c *messageCache) AttachmentBytesUsedByUser(userID string) (int64, error) {
-	rows, err := c.db.Query(selectAttachmentsSizeByUserIDQuery, userID, time.Now().Unix())
+func (c *commonMessageCache) AttachmentBytesUsedByUser(userID string) (int64, error) {
+	rows, err := c.db.Query(c.queries.selectAttachmentsSizeByUserID, userID, time.Now().Unix())
 	if err != nil {
 		return 0, err
 	}
 	return c.readAttachmentBytesUsed(rows)
 }
 
-func (c *messageCache) readAttachmentBytesUsed(rows *sql.Rows) (int64, error) {
+func (c *commonMessageCache) readAttachmentBytesUsed(rows *sql.Rows) (int64, error) {
 	defer rows.Close()
 	var size int64
 	if !rows.Next() {
@@ -676,17 +406,45 @@ func (c *messageCache) readAttachmentBytesUsed(rows *sql.Rows) (int64, error) {
 	return size, nil
 }
 
-func (c *messageCache) processMessageBatches() {
+func (c *commonMessageCache) processMessageBatches() {
 	if c.queue == nil {
 		return
 	}
 	for messages := range c.queue.Dequeue() {
-		if err := c.addMessages(messages); err != nil {
+		if err := c.AddMessages(messages); err != nil {
 			log.Tag(tagMessageCache).Err(err).Error("Cannot write message batch")
 		}
 	}
 }
 
+func (c *commonMessageCache) UpdateStats(messages int64) error {
+	_, err := c.db.Exec(c.queries.updateStats, messages)
+	return err
+}
+
+func (c *commonMessageCache) Stats() (messages int64, err error) {
+	rows, err := c.db.Query(c.queries.selectStats)
+	if err != nil {
+		return 0, err
+	}
+	defer rows.Close()
+	if !rows.Next() {
+		return 0, errNoRows
+	}
+	if err := rows.Scan(&messages); err != nil {
+		return 0, err
+	}
+	return messages, nil
+}
+
+func (c *commonMessageCache) DB() *sql.DB {
+	return c.db
+}
+
+func (c *commonMessageCache) Close() error {
+	return c.db.Close()
+}
+
 func readMessages(rows *sql.Rows) ([]*message, error) {
 	defer rows.Close()
 	messages := make([]*message, 0)
@@ -776,257 +534,3 @@ func readMessage(rows *sql.Rows) (*message, error) {
 		Encoding:    encoding,
 	}, nil
 }
-
-func (c *messageCache) UpdateStats(messages int64) error {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	_, err := c.db.Exec(updateStatsQuery, messages)
-	return err
-}
-
-func (c *messageCache) Stats() (messages int64, err error) {
-	rows, err := c.db.Query(selectStatsQuery)
-	if err != nil {
-		return 0, err
-	}
-	defer rows.Close()
-	if !rows.Next() {
-		return 0, errNoRows
-	}
-	if err := rows.Scan(&messages); err != nil {
-		return 0, err
-	}
-	return messages, nil
-}
-
-func (c *messageCache) Close() error {
-	return c.db.Close()
-}
-
-func setupMessagesDB(db *sql.DB, startupQueries string, cacheDuration time.Duration) error {
-	// Run startup queries
-	if startupQueries != "" {
-		if _, err := db.Exec(startupQueries); err != nil {
-			return err
-		}
-	}
-
-	// If 'messages' table does not exist, this must be a new database
-	rowsMC, err := db.Query(selectMessagesCountQuery)
-	if err != nil {
-		return setupNewCacheDB(db)
-	}
-	rowsMC.Close()
-
-	// If 'messages' table exists, check 'schemaVersion' table
-	schemaVersion := 0
-	rowsSV, err := db.Query(selectSchemaVersionQuery)
-	if err == nil {
-		defer rowsSV.Close()
-		if !rowsSV.Next() {
-			return errors.New("cannot determine schema version: cache file may be corrupt")
-		}
-		if err := rowsSV.Scan(&schemaVersion); err != nil {
-			return err
-		}
-		rowsSV.Close()
-	}
-
-	// Do migrations
-	if schemaVersion == currentSchemaVersion {
-		return nil
-	} else if schemaVersion > currentSchemaVersion {
-		return fmt.Errorf("unexpected schema version: version %d is higher than current version %d", schemaVersion, currentSchemaVersion)
-	}
-	for i := schemaVersion; i < currentSchemaVersion; i++ {
-		fn, ok := migrations[i]
-		if !ok {
-			return fmt.Errorf("cannot find migration step from schema version %d to %d", i, i+1)
-		} else if err := fn(db, cacheDuration); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
-func setupNewCacheDB(db *sql.DB) error {
-	if _, err := db.Exec(createMessagesTableQuery); err != nil {
-		return err
-	}
-	if _, err := db.Exec(createSchemaVersionTableQuery); err != nil {
-		return err
-	}
-	if _, err := db.Exec(insertSchemaVersion, currentSchemaVersion); err != nil {
-		return err
-	}
-	return nil
-}
-
-func migrateFrom0(db *sql.DB, _ time.Duration) error {
-	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 0 to 1")
-	if _, err := db.Exec(migrate0To1AlterMessagesTableQuery); err != nil {
-		return err
-	}
-	if _, err := db.Exec(createSchemaVersionTableQuery); err != nil {
-		return err
-	}
-	if _, err := db.Exec(insertSchemaVersion, 1); err != nil {
-		return err
-	}
-	return nil
-}
-
-func migrateFrom1(db *sql.DB, _ time.Duration) error {
-	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 1 to 2")
-	if _, err := db.Exec(migrate1To2AlterMessagesTableQuery); err != nil {
-		return err
-	}
-	if _, err := db.Exec(updateSchemaVersion, 2); err != nil {
-		return err
-	}
-	return nil
-}
-
-func migrateFrom2(db *sql.DB, _ time.Duration) error {
-	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 2 to 3")
-	if _, err := db.Exec(migrate2To3AlterMessagesTableQuery); err != nil {
-		return err
-	}
-	if _, err := db.Exec(updateSchemaVersion, 3); err != nil {
-		return err
-	}
-	return nil
-}
-
-func migrateFrom3(db *sql.DB, _ time.Duration) error {
-	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 3 to 4")
-	if _, err := db.Exec(migrate3To4AlterMessagesTableQuery); err != nil {
-		return err
-	}
-	if _, err := db.Exec(updateSchemaVersion, 4); err != nil {
-		return err
-	}
-	return nil
-}
-
-func migrateFrom4(db *sql.DB, _ time.Duration) error {
-	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 4 to 5")
-	if _, err := db.Exec(migrate4To5AlterMessagesTableQuery); err != nil {
-		return err
-	}
-	if _, err := db.Exec(updateSchemaVersion, 5); err != nil {
-		return err
-	}
-	return nil
-}
-
-func migrateFrom5(db *sql.DB, _ time.Duration) error {
-	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 5 to 6")
-	if _, err := db.Exec(migrate5To6AlterMessagesTableQuery); err != nil {
-		return err
-	}
-	if _, err := db.Exec(updateSchemaVersion, 6); err != nil {
-		return err
-	}
-	return nil
-}
-
-func migrateFrom6(db *sql.DB, _ time.Duration) error {
-	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 6 to 7")
-	if _, err := db.Exec(migrate6To7AlterMessagesTableQuery); err != nil {
-		return err
-	}
-	if _, err := db.Exec(updateSchemaVersion, 7); err != nil {
-		return err
-	}
-	return nil
-}
-
-func migrateFrom7(db *sql.DB, _ time.Duration) error {
-	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 7 to 8")
-	if _, err := db.Exec(migrate7To8AlterMessagesTableQuery); err != nil {
-		return err
-	}
-	if _, err := db.Exec(updateSchemaVersion, 8); err != nil {
-		return err
-	}
-	return nil
-}
-
-func migrateFrom8(db *sql.DB, _ time.Duration) error {
-	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 8 to 9")
-	if _, err := db.Exec(migrate8To9AlterMessagesTableQuery); err != nil {
-		return err
-	}
-	if _, err := db.Exec(updateSchemaVersion, 9); err != nil {
-		return err
-	}
-	return nil
-}
-
-func migrateFrom9(db *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(migrate9To10AlterMessagesTableQuery); err != nil {
-		return err
-	}
-	if _, err := tx.Exec(migrate9To10UpdateMessageExpiryQuery, int64(cacheDuration.Seconds())); err != nil {
-		return err
-	}
-	if _, err := tx.Exec(updateSchemaVersion, 10); err != nil {
-		return err
-	}
-	return tx.Commit()
-}
-
-func migrateFrom10(db *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(migrate10To11AlterMessagesTableQuery); err != nil {
-		return err
-	}
-	if _, err := tx.Exec(updateSchemaVersion, 11); err != nil {
-		return err
-	}
-	return tx.Commit()
-}
-
-func migrateFrom11(db *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(migrate11To12AlterMessagesTableQuery); err != nil {
-		return err
-	}
-	if _, err := tx.Exec(updateSchemaVersion, 12); err != nil {
-		return err
-	}
-	return tx.Commit()
-}
-
-func migrateFrom12(db *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(migrate12To13AlterMessagesTableQuery); err != nil {
-		return err
-	}
-	if _, err := tx.Exec(updateSchemaVersion, 13); err != nil {
-		return err
-	}
-	return tx.Commit()
-}

server/message_cache_pg.go

@@ -0,0 +1,193 @@
+package server
+
+import (
+	"database/sql"
+	"strings"
+	"time"
+
+	_ "github.com/jackc/pgx/v5/stdlib" // PostgreSQL driver
+
+	"heckel.io/ntfy/v2/util"
+)
+
+// PostgreSQL schema version (starts at latest, no migrations needed initially)
+const pgCurrentSchemaVersion = 1
+
+// Messages cache
+const (
+	pgCreateMessagesTableQuery = `
+		BEGIN;
+		CREATE TABLE IF NOT EXISTS messages (
+			id SERIAL PRIMARY KEY,
+			mid TEXT NOT NULL,
+			time INT NOT NULL,
+			expires INT NOT NULL,
+			topic TEXT NOT NULL,
+			message TEXT NOT NULL,
+			title TEXT NOT NULL,
+			priority INT NOT NULL,
+			tags TEXT NOT NULL,
+			click TEXT NOT NULL,
+			icon TEXT NOT NULL,			
+			actions TEXT NOT NULL,
+			attachment_name TEXT NOT NULL,
+			attachment_type TEXT NOT NULL,
+			attachment_size INT NOT NULL,
+			attachment_expires INT NOT NULL,
+			attachment_url TEXT NOT NULL,
+			attachment_deleted BOOLEAN NOT NULL,
+			sender TEXT NOT NULL,
+			"user" TEXT NOT NULL,
+			content_type TEXT NOT NULL,
+			encoding TEXT NOT NULL,
+			published BOOLEAN NOT NULL
+		);
+		CREATE INDEX IF NOT EXISTS idx_mid ON messages (mid);
+		CREATE INDEX IF NOT EXISTS idx_time ON messages (time);
+		CREATE INDEX IF NOT EXISTS idx_topic ON messages (topic);
+		CREATE INDEX IF NOT EXISTS idx_expires ON messages (expires);
+		CREATE INDEX IF NOT EXISTS idx_sender ON messages (sender);
+		CREATE INDEX IF NOT EXISTS idx_user ON messages ("user");
+		CREATE INDEX IF NOT EXISTS idx_attachment_expires ON messages (attachment_expires);
+		CREATE TABLE IF NOT EXISTS stats (
+			key TEXT PRIMARY KEY,
+			value INT
+		);
+		INSERT INTO stats (key, value) VALUES ('messages', 0);
+		CREATE TABLE IF NOT EXISTS schemaVersion (
+			id INT PRIMARY KEY,
+			version INT NOT NULL
+		);
+		INSERT INTO schemaVersion VALUES (1, 1);
+		COMMIT;
+	`
+
+	pgSelectMessagesCountQuery = `SELECT COUNT(*) FROM messages`
+)
+
+var (
+	pgMessageCacheQueries = &messageCacheQueries{
+		insertMessage: `
+			INSERT INTO messages (mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, attachment_deleted, sender, "user", content_type, encoding, published)
+			VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14, $15, $16, $17, $18, $19, $20, $21, $22)
+		`,
+		deleteMessage:                `DELETE FROM messages WHERE mid = $1`,
+		updateMessagesForTopicExpiry: `UPDATE messages SET expires = $1 WHERE topic = $2`,
+		selectRowIDFromMessageID:     `SELECT id FROM messages WHERE mid = $1`,
+		selectMessagesByID: `
+		SELECT mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, sender, "user", content_type, encoding
+		FROM messages
+		WHERE mid = $1
+	`,
+		selectMessagesSinceTime: `
+		SELECT mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, sender, "user", content_type, encoding
+		FROM messages
+		WHERE topic = $1 AND time >= $2 AND published = TRUE
+		ORDER BY time, id
+	`,
+		selectMessagesSinceTimeIncludeScheduled: `
+		SELECT mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, sender, "user", content_type, encoding
+		FROM messages
+		WHERE topic = $1 AND time >= $2
+		ORDER BY time, id
+	`,
+		selectMessagesSinceID: `
+		SELECT mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, sender, "user", content_type, encoding
+		FROM messages
+		WHERE topic = $1 AND id > $2 AND published = TRUE
+		ORDER BY time, id
+	`,
+		selectMessagesSinceIDIncludeScheduled: `
+		SELECT mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, sender, "user", content_type, encoding
+		FROM messages
+		WHERE topic = $1 AND (id > $2 OR published = FALSE)
+		ORDER BY time, id
+	`,
+		selectMessagesLatest: `
+		SELECT mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, sender, "user", content_type, encoding
+		FROM messages
+		WHERE topic = $1 AND published = TRUE
+		ORDER BY time DESC, id DESC
+		LIMIT 1
+	`,
+		selectMessagesDue: `
+		SELECT mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, sender, "user", content_type, encoding
+		FROM messages
+		WHERE time <= $1 AND published = FALSE
+		ORDER BY time, id
+	`,
+		selectMessagesExpired:      `SELECT mid FROM messages WHERE expires <= $1 AND published = TRUE`,
+		updateMessagePublished:     `UPDATE messages SET published = TRUE WHERE mid = $1`,
+		selectMessageCountPerTopic: `SELECT topic, COUNT(*) FROM messages GROUP BY topic`,
+		selectTopics:               `SELECT topic FROM messages GROUP BY topic`,
+
+		updateAttachmentDeleted:       `UPDATE messages SET attachment_deleted = TRUE WHERE mid = $1`,
+		selectAttachmentsExpired:      `SELECT mid FROM messages WHERE attachment_expires > 0 AND attachment_expires <= $1 AND attachment_deleted = FALSE`,
+		selectAttachmentsSizeBySender: `SELECT COALESCE(SUM(attachment_size), 0) FROM messages WHERE "user" = '' AND sender = $1 AND attachment_expires >= $2`,
+		selectAttachmentsSizeByUserID: `SELECT COALESCE(SUM(attachment_size), 0) FROM messages WHERE "user" = $1 AND attachment_expires >= $2`,
+
+		selectStats: `SELECT value FROM stats WHERE key = 'messages'`,
+		updateStats: `UPDATE stats SET value = $1 WHERE key = 'messages'`,
+	}
+)
+
+type pgMessageCache struct {
+	*commonMessageCache
+}
+
+var _ MessageCache = (*pgMessageCache)(nil)
+
+// newPgCache creates a PostgreSQL-backed message cache
+func newPgCache(connectionString, startupQueries string, batchSize int, batchTimeout time.Duration) (*pgMessageCache, error) {
+	db, err := sql.Open("pgx", connectionString)
+	if err != nil {
+		return nil, err
+	}
+	if err := setupPgMessagesDB(db, startupQueries); err != nil {
+		return nil, err
+	}
+	var queue *util.BatchingQueue[*message]
+	if batchSize > 0 || batchTimeout > 0 {
+		queue = util.NewBatchingQueue[*message](batchSize, batchTimeout)
+	}
+	cache := &pgMessageCache{
+		commonMessageCache: &commonMessageCache{
+			db:      db,
+			queue:   queue,
+			queries: pgMessageCacheQueries,
+		},
+	}
+	go cache.processMessageBatches()
+	return cache, nil
+}
+
+func setupPgMessagesDB(db *sql.DB, startupQueries string) error {
+	// Run startup queries
+	if startupQueries != "" {
+		if _, err := db.Exec(startupQueries); err != nil {
+			return err
+		}
+	}
+
+	// If 'messages' table does not exist, this must be a new database
+	rowsMC, err := db.Query(pgSelectMessagesCountQuery)
+	if err != nil {
+		return setupNewPgCacheDB(db)
+	}
+	rowsMC.Close()
+
+	// Future: Add migrations here when schema changes
+	return nil
+}
+
+func setupNewPgCacheDB(db *sql.DB) error {
+	if _, err := db.Exec(pgCreateMessagesTableQuery); err != nil {
+		return err
+	}
+	return nil
+}
+
+// isPostgres checks if the connection string indicates a PostgreSQL database
+func isPostgres(connectionString string) bool {
+	return strings.HasPrefix(connectionString, "postgres:")
+}

server/message_cache_sqlite.go

@@ -0,0 +1,571 @@
+package server
+
+import (
+	"database/sql"
+	"errors"
+	"fmt"
+	"time"
+
+	_ "github.com/mattn/go-sqlite3" // SQLite driver
+
+	"heckel.io/ntfy/v2/log"
+	"heckel.io/ntfy/v2/util"
+)
+
+var (
+	errUnexpectedMessageType = errors.New("unexpected message type")
+	errMessageNotFound       = errors.New("message not found")
+	errNoRows                = errors.New("no rows found")
+)
+
+// Messages cache
+const (
+	createMessagesTableQuery = `
+		BEGIN;
+		CREATE TABLE IF NOT EXISTS messages (
+			id INTEGER PRIMARY KEY AUTOINCREMENT,
+			mid TEXT NOT NULL,
+			time INT NOT NULL,
+			expires INT NOT NULL,
+			topic TEXT NOT NULL,
+			message TEXT NOT NULL,
+			title TEXT NOT NULL,
+			priority INT NOT NULL,
+			tags TEXT NOT NULL,
+			click TEXT NOT NULL,
+			icon TEXT NOT NULL,			
+			actions TEXT NOT NULL,
+			attachment_name TEXT NOT NULL,
+			attachment_type TEXT NOT NULL,
+			attachment_size INT NOT NULL,
+			attachment_expires INT NOT NULL,
+			attachment_url TEXT NOT NULL,
+			attachment_deleted INT NOT NULL,
+			sender TEXT NOT NULL,
+			user TEXT NOT NULL,
+			content_type TEXT NOT NULL,
+			encoding TEXT NOT NULL,
+			published INT NOT NULL
+		);
+		CREATE INDEX IF NOT EXISTS idx_mid ON messages (mid);
+		CREATE INDEX IF NOT EXISTS idx_time ON messages (time);
+		CREATE INDEX IF NOT EXISTS idx_topic ON messages (topic);
+		CREATE INDEX IF NOT EXISTS idx_expires ON messages (expires);
+		CREATE INDEX IF NOT EXISTS idx_sender ON messages (sender);
+		CREATE INDEX IF NOT EXISTS idx_user ON messages (user);
+		CREATE INDEX IF NOT EXISTS idx_attachment_expires ON messages (attachment_expires);
+		CREATE TABLE IF NOT EXISTS stats (
+			key TEXT PRIMARY KEY,
+			value INT
+		);
+		INSERT INTO stats (key, value) VALUES ('messages', 0);
+		COMMIT;
+	`
+)
+
+var (
+	sqliteMessageCacheQueries = &messageCacheQueries{
+		insertMessage: `
+			INSERT INTO messages (mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, attachment_deleted, sender, user, content_type, encoding, published)
+			VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+		`,
+		deleteMessage:                `DELETE FROM messages WHERE mid = ?`,
+		updateMessagesForTopicExpiry: `UPDATE messages SET expires = ? WHERE topic = ?`,
+		selectRowIDFromMessageID:     `SELECT id FROM messages WHERE mid = ?`, // Do not include topic, see #336 and TestServer_PollSinceID_MultipleTopics
+		selectMessagesByID: `
+		SELECT mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, sender, user, content_type, encoding
+		FROM messages
+		WHERE mid = ?
+	`,
+		selectMessagesSinceTime: `
+		SELECT mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, sender, user, content_type, encoding
+		FROM messages
+		WHERE topic = ? AND time >= ? AND published = 1
+		ORDER BY time, id
+	`,
+		selectMessagesSinceTimeIncludeScheduled: `
+		SELECT mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, sender, user, content_type, encoding
+		FROM messages
+		WHERE topic = ? AND time >= ?
+		ORDER BY time, id
+	`,
+		selectMessagesSinceID: `
+		SELECT mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, sender, user, content_type, encoding
+		FROM messages
+		WHERE topic = ? AND id > ? AND published = 1
+		ORDER BY time, id
+	`,
+		selectMessagesSinceIDIncludeScheduled: `
+		SELECT mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, sender, user, content_type, encoding
+		FROM messages
+		WHERE topic = ? AND (id > ? OR published = 0)
+		ORDER BY time, id
+	`,
+		selectMessagesLatest: `
+		SELECT mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, sender, user, content_type, encoding
+		FROM messages
+		WHERE topic = ? AND published = 1
+		ORDER BY time DESC, id DESC
+		LIMIT 1
+	`,
+		selectMessagesDue: `
+		SELECT mid, time, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, sender, user, content_type, encoding
+		FROM messages
+		WHERE time <= ? AND published = 0
+		ORDER BY time, id
+	`,
+		selectMessagesExpired:      `SELECT mid FROM messages WHERE expires <= ? AND published = 1`,
+		updateMessagePublished:     `UPDATE messages SET published = 1 WHERE mid = ?`,
+		selectMessageCountPerTopic: `SELECT topic, COUNT(*) FROM messages GROUP BY topic`,
+		selectTopics:               `SELECT topic FROM messages GROUP BY topic`,
+
+		updateAttachmentDeleted:       `UPDATE messages SET attachment_deleted = 1 WHERE mid = ?`,
+		selectAttachmentsExpired:      `SELECT mid FROM messages WHERE attachment_expires > 0 AND attachment_expires <= ? AND attachment_deleted = 0`,
+		selectAttachmentsSizeBySender: `SELECT IFNULL(SUM(attachment_size), 0) FROM messages WHERE user = '' AND sender = ? AND attachment_expires >= ?`,
+		selectAttachmentsSizeByUserID: `SELECT IFNULL(SUM(attachment_size), 0) FROM messages WHERE user = ? AND attachment_expires >= ?`,
+
+		selectStats: `SELECT value FROM stats WHERE key = 'messages'`,
+		updateStats: `UPDATE stats SET value = ? WHERE key = 'messages'`,
+	}
+)
+
+// Schema management queries
+const (
+	currentSchemaVersion          = 13
+	createSchemaVersionTableQuery = `
+		CREATE TABLE IF NOT EXISTS schemaVersion (
+			id INT PRIMARY KEY,
+			version INT NOT NULL
+		);
+	`
+	insertSchemaVersion      = `INSERT INTO schemaVersion VALUES (1, ?)`
+	updateSchemaVersion      = `UPDATE schemaVersion SET version = ? WHERE id = 1`
+	selectSchemaVersionQuery = `SELECT version FROM schemaVersion WHERE id = 1`
+	selectMessagesCountQuery = `SELECT COUNT(*) FROM messages`
+
+	// 0 -> 1
+	migrate0To1AlterMessagesTableQuery = `
+		BEGIN;
+		ALTER TABLE messages ADD COLUMN title TEXT NOT NULL DEFAULT('');
+		ALTER TABLE messages ADD COLUMN priority INT NOT NULL DEFAULT(0);
+		ALTER TABLE messages ADD COLUMN tags TEXT NOT NULL DEFAULT('');
+		COMMIT;
+	`
+
+	// 1 -> 2
+	migrate1To2AlterMessagesTableQuery = `
+		ALTER TABLE messages ADD COLUMN published INT NOT NULL DEFAULT(1);
+	`
+
+	// 2 -> 3
+	migrate2To3AlterMessagesTableQuery = `
+		BEGIN;
+		ALTER TABLE messages ADD COLUMN click TEXT NOT NULL DEFAULT('');
+		ALTER TABLE messages ADD COLUMN attachment_name TEXT NOT NULL DEFAULT('');
+		ALTER TABLE messages ADD COLUMN attachment_type TEXT NOT NULL DEFAULT('');
+		ALTER TABLE messages ADD COLUMN attachment_size INT NOT NULL DEFAULT('0');
+		ALTER TABLE messages ADD COLUMN attachment_expires INT NOT NULL DEFAULT('0');
+		ALTER TABLE messages ADD COLUMN attachment_owner TEXT NOT NULL DEFAULT('');
+		ALTER TABLE messages ADD COLUMN attachment_url TEXT NOT NULL DEFAULT('');
+		COMMIT;
+	`
+	// 3 -> 4
+	migrate3To4AlterMessagesTableQuery = `
+		ALTER TABLE messages ADD COLUMN encoding TEXT NOT NULL DEFAULT('');
+	`
+
+	// 4 -> 5
+	migrate4To5AlterMessagesTableQuery = `
+		BEGIN;
+		CREATE TABLE IF NOT EXISTS messages_new (
+			id INTEGER PRIMARY KEY AUTOINCREMENT,
+			mid TEXT NOT NULL,
+			time INT NOT NULL,
+			topic TEXT NOT NULL,
+			message TEXT NOT NULL,
+			title TEXT NOT NULL,
+			priority INT NOT NULL,
+			tags TEXT NOT NULL,
+			click TEXT NOT NULL,
+			attachment_name TEXT NOT NULL,
+			attachment_type TEXT NOT NULL,
+			attachment_size INT NOT NULL,
+			attachment_expires INT NOT NULL,
+			attachment_url TEXT NOT NULL,
+			attachment_owner TEXT NOT NULL,
+			encoding TEXT NOT NULL,
+			published INT NOT NULL
+		);
+		CREATE INDEX IF NOT EXISTS idx_mid ON messages_new (mid);
+		CREATE INDEX IF NOT EXISTS idx_topic ON messages_new (topic);
+		INSERT
+			INTO messages_new (
+				mid, time, topic, message, title, priority, tags, click, attachment_name, attachment_type,
+				attachment_size, attachment_expires, attachment_url, attachment_owner, encoding, published)
+			SELECT
+				id, time, topic, message, title, priority, tags, click, attachment_name, attachment_type,
+				attachment_size, attachment_expires, attachment_url, attachment_owner, encoding, published
+			FROM messages;
+		DROP TABLE messages;
+		ALTER TABLE messages_new RENAME TO messages;
+		COMMIT;
+	`
+
+	// 5 -> 6
+	migrate5To6AlterMessagesTableQuery = `
+		ALTER TABLE messages ADD COLUMN actions TEXT NOT NULL DEFAULT('');
+	`
+
+	// 6 -> 7
+	migrate6To7AlterMessagesTableQuery = `
+		ALTER TABLE messages RENAME COLUMN attachment_owner TO sender;
+	`
+
+	// 7 -> 8
+	migrate7To8AlterMessagesTableQuery = `
+		ALTER TABLE messages ADD COLUMN icon TEXT NOT NULL DEFAULT('');
+	`
+
+	// 8 -> 9
+	migrate8To9AlterMessagesTableQuery = `
+		CREATE INDEX IF NOT EXISTS idx_time ON messages (time);
+	`
+
+	// 9 -> 10
+	migrate9To10AlterMessagesTableQuery = `
+		ALTER TABLE messages ADD COLUMN user TEXT NOT NULL DEFAULT('');
+		ALTER TABLE messages ADD COLUMN attachment_deleted INT NOT NULL DEFAULT('0');
+		ALTER TABLE messages ADD COLUMN expires INT NOT NULL DEFAULT('0');
+		CREATE INDEX IF NOT EXISTS idx_expires ON messages (expires);
+		CREATE INDEX IF NOT EXISTS idx_sender ON messages (sender);
+		CREATE INDEX IF NOT EXISTS idx_user ON messages (user);
+		CREATE INDEX IF NOT EXISTS idx_attachment_expires ON messages (attachment_expires);
+	`
+	migrate9To10UpdateMessageExpiryQuery = `UPDATE messages SET expires = time + ?`
+
+	// 10 -> 11
+	migrate10To11AlterMessagesTableQuery = `
+		CREATE TABLE IF NOT EXISTS stats (
+			key TEXT PRIMARY KEY,
+			value INT
+		);
+		INSERT INTO stats (key, value) VALUES ('messages', 0);
+	`
+
+	// 11 -> 12
+	migrate11To12AlterMessagesTableQuery = `
+		ALTER TABLE messages ADD COLUMN content_type TEXT NOT NULL DEFAULT('');
+	`
+
+	// 12 -> 13
+	migrate12To13AlterMessagesTableQuery = `
+		CREATE INDEX IF NOT EXISTS idx_topic ON messages (topic);
+	`
+)
+
+var (
+	migrations = map[int]func(db *sql.DB, cacheDuration time.Duration) error{
+		0:  migrateFrom0,
+		1:  migrateFrom1,
+		2:  migrateFrom2,
+		3:  migrateFrom3,
+		4:  migrateFrom4,
+		5:  migrateFrom5,
+		6:  migrateFrom6,
+		7:  migrateFrom7,
+		8:  migrateFrom8,
+		9:  migrateFrom9,
+		10: migrateFrom10,
+		11: migrateFrom11,
+		12: migrateFrom12,
+	}
+)
+
+type sqliteMessageCache struct {
+	*commonMessageCache
+}
+
+var _ MessageCache = (*sqliteMessageCache)(nil)
+
+// newSqliteCache creates a SQLite file-backed cache
+func newSqliteCache(filename, startupQueries string, cacheDuration time.Duration, batchSize int, batchTimeout time.Duration, nop bool) (*sqliteMessageCache, error) {
+	db, err := sql.Open("sqlite3", filename)
+	if err != nil {
+		return nil, err
+	}
+	if err := setupMessagesDB(db, startupQueries, cacheDuration); err != nil {
+		return nil, err
+	}
+	var queue *util.BatchingQueue[*message]
+	if batchSize > 0 || batchTimeout > 0 {
+		queue = util.NewBatchingQueue[*message](batchSize, batchTimeout)
+	}
+	cache := &sqliteMessageCache{
+		commonMessageCache: &commonMessageCache{
+			db:      db,
+			queue:   queue,
+			queries: sqliteMessageCacheQueries,
+			nop:     nop,
+		},
+	}
+	go cache.processMessageBatches()
+	return cache, nil
+}
+
+// newMemCache creates an in-memory cache
+func newMemCache() (*sqliteMessageCache, error) {
+	return newSqliteCache(createMemoryFilename(), "", 0, 0, 0, false)
+}
+
+// newNopCache creates an in-memory cache that discards all messages;
+// it is always empty and can be used if caching is entirely disabled
+func newNopCache() (*sqliteMessageCache, error) {
+	return newSqliteCache(createMemoryFilename(), "", 0, 0, 0, true)
+}
+
+// createMemoryFilename creates a unique memory filename to use for the SQLite backend.
+// From mattn/go-sqlite3: "Each connection to ":memory:" opens a brand new in-memory
+// sql database, so if the stdlib's sql engine happens to open another connection and
+// you've only specified ":memory:", that connection will see a brand new database.
+// A workaround is to use "file::memory:?cache=shared" (or "file:foobar?mode=memory&cache=shared").
+// Every connection to this string will point to the same in-memory database."
+func createMemoryFilename() string {
+	return fmt.Sprintf("file:%s?mode=memory&cache=shared", util.RandomString(10))
+}
+
+// AddMessage stores a message to the message cache synchronously, or queues it to be stored at a later date asyncronously.
+// The message is queued only if "batchSize" or "batchTimeout" are passed to the constructor.
+func (c *sqliteMessageCache) AddMessage(m *message) error {
+	if c.nop {
+		return nil
+	}
+	return c.commonMessageCache.AddMessage(m)
+}
+
+func setupMessagesDB(db *sql.DB, startupQueries string, cacheDuration time.Duration) error {
+	// Run startup queries
+	if startupQueries != "" {
+		if _, err := db.Exec(startupQueries); err != nil {
+			return err
+		}
+	}
+
+	// If 'messages' table does not exist, this must be a new database
+	rowsMC, err := db.Query(selectMessagesCountQuery)
+	if err != nil {
+		return setupNewCacheDB(db)
+	}
+	rowsMC.Close()
+
+	// If 'messages' table exists, check 'schemaVersion' table
+	schemaVersion := 0
+	rowsSV, err := db.Query(selectSchemaVersionQuery)
+	if err == nil {
+		defer rowsSV.Close()
+		if !rowsSV.Next() {
+			return errors.New("cannot determine schema version: cache file may be corrupt")
+		}
+		if err := rowsSV.Scan(&schemaVersion); err != nil {
+			return err
+		}
+		rowsSV.Close()
+	}
+
+	// Do migrations
+	if schemaVersion == currentSchemaVersion {
+		return nil
+	} else if schemaVersion > currentSchemaVersion {
+		return fmt.Errorf("unexpected schema version: version %d is higher than current version %d", schemaVersion, currentSchemaVersion)
+	}
+	for i := schemaVersion; i < currentSchemaVersion; i++ {
+		fn, ok := migrations[i]
+		if !ok {
+			return fmt.Errorf("cannot find migration step from schema version %d to %d", i, i+1)
+		} else if err := fn(db, cacheDuration); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func setupNewCacheDB(db *sql.DB) error {
+	if _, err := db.Exec(createMessagesTableQuery); err != nil {
+		return err
+	}
+	if _, err := db.Exec(createSchemaVersionTableQuery); err != nil {
+		return err
+	}
+	if _, err := db.Exec(insertSchemaVersion, currentSchemaVersion); err != nil {
+		return err
+	}
+	return nil
+}
+
+func migrateFrom0(db *sql.DB, _ time.Duration) error {
+	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 0 to 1")
+	if _, err := db.Exec(migrate0To1AlterMessagesTableQuery); err != nil {
+		return err
+	}
+	if _, err := db.Exec(createSchemaVersionTableQuery); err != nil {
+		return err
+	}
+	if _, err := db.Exec(insertSchemaVersion, 1); err != nil {
+		return err
+	}
+	return nil
+}
+
+func migrateFrom1(db *sql.DB, _ time.Duration) error {
+	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 1 to 2")
+	if _, err := db.Exec(migrate1To2AlterMessagesTableQuery); err != nil {
+		return err
+	}
+	if _, err := db.Exec(updateSchemaVersion, 2); err != nil {
+		return err
+	}
+	return nil
+}
+
+func migrateFrom2(db *sql.DB, _ time.Duration) error {
+	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 2 to 3")
+	if _, err := db.Exec(migrate2To3AlterMessagesTableQuery); err != nil {
+		return err
+	}
+	if _, err := db.Exec(updateSchemaVersion, 3); err != nil {
+		return err
+	}
+	return nil
+}
+
+func migrateFrom3(db *sql.DB, _ time.Duration) error {
+	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 3 to 4")
+	if _, err := db.Exec(migrate3To4AlterMessagesTableQuery); err != nil {
+		return err
+	}
+	if _, err := db.Exec(updateSchemaVersion, 4); err != nil {
+		return err
+	}
+	return nil
+}
+
+func migrateFrom4(db *sql.DB, _ time.Duration) error {
+	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 4 to 5")
+	if _, err := db.Exec(migrate4To5AlterMessagesTableQuery); err != nil {
+		return err
+	}
+	if _, err := db.Exec(updateSchemaVersion, 5); err != nil {
+		return err
+	}
+	return nil
+}
+
+func migrateFrom5(db *sql.DB, _ time.Duration) error {
+	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 5 to 6")
+	if _, err := db.Exec(migrate5To6AlterMessagesTableQuery); err != nil {
+		return err
+	}
+	if _, err := db.Exec(updateSchemaVersion, 6); err != nil {
+		return err
+	}
+	return nil
+}
+
+func migrateFrom6(db *sql.DB, _ time.Duration) error {
+	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 6 to 7")
+	if _, err := db.Exec(migrate6To7AlterMessagesTableQuery); err != nil {
+		return err
+	}
+	if _, err := db.Exec(updateSchemaVersion, 7); err != nil {
+		return err
+	}
+	return nil
+}
+
+func migrateFrom7(db *sql.DB, _ time.Duration) error {
+	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 7 to 8")
+	if _, err := db.Exec(migrate7To8AlterMessagesTableQuery); err != nil {
+		return err
+	}
+	if _, err := db.Exec(updateSchemaVersion, 8); err != nil {
+		return err
+	}
+	return nil
+}
+
+func migrateFrom8(db *sql.DB, _ time.Duration) error {
+	log.Tag(tagMessageCache).Info("Migrating cache database schema: from 8 to 9")
+	if _, err := db.Exec(migrate8To9AlterMessagesTableQuery); err != nil {
+		return err
+	}
+	if _, err := db.Exec(updateSchemaVersion, 9); err != nil {
+		return err
+	}
+	return nil
+}
+
+func migrateFrom9(db *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(migrate9To10AlterMessagesTableQuery); err != nil {
+		return err
+	}
+	if _, err := tx.Exec(migrate9To10UpdateMessageExpiryQuery, int64(cacheDuration.Seconds())); err != nil {
+		return err
+	}
+	if _, err := tx.Exec(updateSchemaVersion, 10); err != nil {
+		return err
+	}
+	return tx.Commit()
+}
+
+func migrateFrom10(db *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(migrate10To11AlterMessagesTableQuery); err != nil {
+		return err
+	}
+	if _, err := tx.Exec(updateSchemaVersion, 11); err != nil {
+		return err
+	}
+	return tx.Commit()
+}
+
+func migrateFrom11(db *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(migrate11To12AlterMessagesTableQuery); err != nil {
+		return err
+	}
+	if _, err := tx.Exec(updateSchemaVersion, 12); err != nil {
+		return err
+	}
+	return tx.Commit()
+}
+
+func migrateFrom12(db *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(migrate12To13AlterMessagesTableQuery); err != nil {
+		return err
+	}
+	if _, err := tx.Exec(updateSchemaVersion, 13); err != nil {
+		return err
+	}
+	return tx.Commit()
+}

server/message_cache_test.go

@@ -21,7 +21,7 @@ func TestMemCache_Messages(t *testing.T) {
 	testCacheMessages(t, newMemTestCache(t))
 }
 
-func testCacheMessages(t *testing.T, c *messageCache) {
+func testCacheMessages(t *testing.T, c MessageCache) {
 	m1 := newDefaultMessage("mytopic", "my message")
 	m1.Time = 1
 
@@ -100,7 +100,7 @@ func TestMemCache_MessagesLock(t *testing.T) {
 	testCacheMessagesLock(t, newMemTestCache(t))
 }
 
-func testCacheMessagesLock(t *testing.T, c *messageCache) {
+func testCacheMessagesLock(t *testing.T, c MessageCache) {
 	var wg sync.WaitGroup
 	for i := 0; i < 5000; i++ {
 		wg.Add(1)
@@ -120,7 +120,7 @@ func TestMemCache_MessagesScheduled(t *testing.T) {
 	testCacheMessagesScheduled(t, newMemTestCache(t))
 }
 
-func testCacheMessagesScheduled(t *testing.T, c *messageCache) {
+func testCacheMessagesScheduled(t *testing.T, c MessageCache) {
 	m1 := newDefaultMessage("mytopic", "message 1")
 	m2 := newDefaultMessage("mytopic", "message 2")
 	m2.Time = time.Now().Add(time.Hour).Unix()
@@ -154,7 +154,7 @@ func TestMemCache_Topics(t *testing.T) {
 	testCacheTopics(t, newMemTestCache(t))
 }
 
-func testCacheTopics(t *testing.T, c *messageCache) {
+func testCacheTopics(t *testing.T, c MessageCache) {
 	require.Nil(t, c.AddMessage(newDefaultMessage("topic1", "my example message")))
 	require.Nil(t, c.AddMessage(newDefaultMessage("topic2", "message 1")))
 	require.Nil(t, c.AddMessage(newDefaultMessage("topic2", "message 2")))
@@ -177,7 +177,7 @@ func TestMemCache_MessagesTagsPrioAndTitle(t *testing.T) {
 	testCacheMessagesTagsPrioAndTitle(t, newMemTestCache(t))
 }
 
-func testCacheMessagesTagsPrioAndTitle(t *testing.T, c *messageCache) {
+func testCacheMessagesTagsPrioAndTitle(t *testing.T, c MessageCache) {
 	m := newDefaultMessage("mytopic", "some message")
 	m.Tags = []string{"tag1", "tag2"}
 	m.Priority = 5
@@ -198,7 +198,7 @@ func TestMemCache_MessagesSinceID(t *testing.T) {
 	testCacheMessagesSinceID(t, newMemTestCache(t))
 }
 
-func testCacheMessagesSinceID(t *testing.T, c *messageCache) {
+func testCacheMessagesSinceID(t *testing.T, c MessageCache) {
 	m1 := newDefaultMessage("mytopic", "message 1")
 	m1.Time = 100
 	m2 := newDefaultMessage("mytopic", "message 2")
@@ -268,7 +268,7 @@ func TestMemCache_Prune(t *testing.T) {
 	testCachePrune(t, newMemTestCache(t))
 }
 
-func testCachePrune(t *testing.T, c *messageCache) {
+func testCachePrune(t *testing.T, c MessageCache) {
 	now := time.Now().Unix()
 
 	m1 := newDefaultMessage("mytopic", "my message")
@@ -315,7 +315,7 @@ func TestMemCache_Attachments(t *testing.T) {
 	testCacheAttachments(t, newMemTestCache(t))
 }
 
-func testCacheAttachments(t *testing.T, c *messageCache) {
+func testCacheAttachments(t *testing.T, c MessageCache) {
 	expires1 := time.Now().Add(-4 * time.Hour).Unix() // Expired
 	m := newDefaultMessage("mytopic", "flower for you")
 	m.ID = "m1"
@@ -397,7 +397,7 @@ func TestMemCache_Attachments_Expired(t *testing.T) {
 	testCacheAttachmentsExpired(t, newMemTestCache(t))
 }
 
-func testCacheAttachmentsExpired(t *testing.T, c *messageCache) {
+func testCacheAttachmentsExpired(t *testing.T, c MessageCache) {
 	m := newDefaultMessage("mytopic", "flower for you")
 	m.ID = "m1"
 	m.Expires = time.Now().Add(time.Hour).Unix()
@@ -473,7 +473,7 @@ func TestSqliteCache_Migration_From0(t *testing.T) {
 
 	// Create cache to trigger migration
 	c := newSqliteTestCacheFromFile(t, filename, "")
-	checkSchemaVersion(t, c.db)
+	checkSchemaVersion(t, c.DB())
 
 	messages, err := c.Messages("mytopic", sinceAllMessages, false)
 	require.Nil(t, err)
@@ -519,7 +519,7 @@ func TestSqliteCache_Migration_From1(t *testing.T) {
 
 	// Create cache to trigger migration
 	c := newSqliteTestCacheFromFile(t, filename, "")
-	checkSchemaVersion(t, c.db)
+	checkSchemaVersion(t, c.DB())
 
 	// Add delayed message
 	delayedMessage := newDefaultMessage("mytopic", "some delayed message")
@@ -537,7 +537,7 @@ func TestSqliteCache_Migration_From1(t *testing.T) {
 	require.Equal(t, 11, len(messages))
 
 	// Check that index "idx_topic" exists
-	rows, err := c.db.Query(`SELECT name FROM sqlite_master WHERE type='index' AND name='idx_topic'`)
+	rows, err := c.DB().Query(`SELECT name FROM sqlite_master WHERE type='index' AND name='idx_topic'`)
 	require.Nil(t, err)
 	require.True(t, rows.Next())
 	var indexName string
@@ -623,7 +623,7 @@ func TestSqliteCache_Migration_From9(t *testing.T) {
 	cacheDuration := 17 * time.Hour
 	c, err := newSqliteCache(filename, "", cacheDuration, 0, 0, false)
 	require.Nil(t, err)
-	checkSchemaVersion(t, c.db)
+	checkSchemaVersion(t, c.DB())
 
 	// Check version
 	rows, err := db.Query(`SELECT version FROM main.schemaVersion WHERE id = 1`)
@@ -681,7 +681,7 @@ func TestMemCache_Sender(t *testing.T) {
 	testSender(t, newMemTestCache(t))
 }
 
-func testSender(t *testing.T, c *messageCache) {
+func testSender(t *testing.T, c MessageCache) {
 	m1 := newDefaultMessage("mytopic", "mymessage")
 	m1.Sender = netip.MustParseAddr("1.2.3.4")
 	require.Nil(t, c.AddMessage(m1))
@@ -720,7 +720,7 @@ func TestMemCache_NopCache(t *testing.T) {
 	require.Empty(t, topics)
 }
 
-func newSqliteTestCache(t *testing.T) *messageCache {
+func newSqliteTestCache(t *testing.T) MessageCache {
 	c, err := newSqliteCache(newSqliteTestCacheFile(t), "", time.Hour, 0, 0, false)
 	if err != nil {
 		t.Fatal(err)
@@ -732,13 +732,13 @@ func newSqliteTestCacheFile(t *testing.T) string {
 	return filepath.Join(t.TempDir(), "cache.db")
 }
 
-func newSqliteTestCacheFromFile(t *testing.T, filename, startupQueries string) *messageCache {
+func newSqliteTestCacheFromFile(t *testing.T, filename, startupQueries string) MessageCache {
 	c, err := newSqliteCache(filename, startupQueries, time.Hour, 0, 0, false)
 	require.Nil(t, err)
 	return c
 }
 
-func newMemTestCache(t *testing.T) *messageCache {
+func newMemTestCache(t *testing.T) MessageCache {
 	c, err := newMemCache()
 	require.Nil(t, err)
 	return c

server/server.go

@@ -56,8 +56,8 @@ type Server struct {
 	messages          int64                               // Total number of messages (persisted if messageCache enabled)
 	messagesHistory   []int64                             // Last n values of the messages counter, used to determine rate
 	userManager       *user.Manager                       // Might be nil!
-	messageCache      *messageCache                       // Database that stores the messages
-	webPush           *webPushStore                       // Database that stores web push subscriptions
+	messageCache      MessageCache                        // Database that stores the messages
+	webPush           WebPushStore                        // Database that stores web push subscriptions
 	fileCache         *fileCache                          // File system based cache that stores attachments
 	stripe            stripeAPI                           // Stripe API, can be replaced with a mock
 	priceCache        *util.LookupCache[map[string]int64] // Stripe price ID -> price as cents (USD implied!)
@@ -173,7 +173,7 @@ func New(conf *Config) (*Server, error) {
 	if err != nil {
 		return nil, err
 	}
-	var webPush *webPushStore
+	var webPush WebPushStore
 	if conf.WebPushPublicKey != "" {
 		webPush, err = newWebPushStore(conf.WebPushFile, conf.WebPushStartupQueries)
 		if err != nil {
@@ -245,9 +245,11 @@ func New(conf *Config) (*Server, error) {
 	return s, nil
 }
 
-func createMessageCache(conf *Config) (*messageCache, error) {
+func createMessageCache(conf *Config) (MessageCache, error) {
 	if conf.CacheDuration == 0 {
 		return newNopCache()
+	} else if isPostgres(conf.CacheFile) {
+		return newPgCache(conf.CacheFile, conf.CacheStartupQueries, conf.CacheBatchSize, conf.CacheBatchTimeout)
 	} else if conf.CacheFile != "" {
 		return newSqliteCache(conf.CacheFile, conf.CacheStartupQueries, conf.CacheDuration, conf.CacheBatchSize, conf.CacheBatchTimeout, false)
 	}

server/server_test.go

@@ -381,7 +381,7 @@ func TestServer_PublishAt(t *testing.T) {
 
 	// Update message time to the past
 	fakeTime := time.Now().Add(-10 * time.Second).Unix()
-	_, err := s.messageCache.db.Exec(`UPDATE messages SET time=?`, fakeTime)
+	_, err := s.messageCache.DB().Exec(`UPDATE messages SET time=?`, fakeTime)
 	require.Nil(t, err)
 
 	// Trigger delayed message sending
@@ -417,7 +417,7 @@ func TestServer_PublishAt_FromUser(t *testing.T) {
 
 	// Update message time to the past
 	fakeTime := time.Now().Add(-10 * time.Second).Unix()
-	_, err := s.messageCache.db.Exec(`UPDATE messages SET time=?`, fakeTime)
+	_, err := s.messageCache.DB().Exec(`UPDATE messages SET time=?`, fakeTime)
 	require.Nil(t, err)
 
 	// Trigger delayed message sending
@@ -2336,7 +2336,7 @@ func TestServer_PublishWhileUpdatingStatsWithLotsOfMessages(t *testing.T) {
 		require.Nil(t, err)
 		messages = append(messages, newDefaultMessage(topicID, "some message"))
 	}
-	require.Nil(t, s.messageCache.addMessages(messages))
+	require.Nil(t, s.messageCache.AddMessages(messages))
 	log.Info("Done: Adding %d messages; took %s", count, time.Since(start).Round(time.Millisecond))
 
 	// Update stats

server/server_webpush_test.go

@@ -238,7 +238,7 @@ func TestServer_WebPush_Expiry(t *testing.T) {
 	addSubscription(t, s, pushService.URL+"/push-receive", "test-topic")
 	requireSubscriptionCount(t, s, "test-topic", 1)
 
-	_, err := s.webPush.db.Exec("UPDATE subscription SET updated_at = ?", time.Now().Add(-55*24*time.Hour).Unix())
+	_, err := s.webPush.DB().Exec("UPDATE subscription SET updated_at = ?", time.Now().Add(-55*24*time.Hour).Unix())
 	require.Nil(t, err)
 
 	s.pruneAndNotifyWebPushSubscriptions()
@@ -248,7 +248,7 @@ func TestServer_WebPush_Expiry(t *testing.T) {
 		return received.Load()
 	})
 
-	_, err = s.webPush.db.Exec("UPDATE subscription SET updated_at = ?", time.Now().Add(-60*24*time.Hour).Unix())
+	_, err = s.webPush.DB().Exec("UPDATE subscription SET updated_at = ?", time.Now().Add(-60*24*time.Hour).Unix())
 	require.Nil(t, err)
 
 	s.pruneAndNotifyWebPushSubscriptions()

server/visitor.go

@@ -53,7 +53,7 @@ const (
 // visitor represents an API user, and its associated rate.Limiter used for rate limiting
 type visitor struct {
 	config              *Config
-	messageCache        *messageCache
+	messageCache        MessageCache
 	userManager         *user.Manager      // May be nil
 	ip                  netip.Addr         // Visitor IP address
 	user                *user.User         // Only set if authenticated user, otherwise nil
@@ -114,7 +114,7 @@ const (
 	visitorLimitBasisTier = visitorLimitBasis("tier")
 )
 
-func newVisitor(conf *Config, messageCache *messageCache, userManager *user.Manager, ip netip.Addr, user *user.User) *visitor {
+func newVisitor(conf *Config, messageCache MessageCache, userManager *user.Manager, ip netip.Addr, user *user.User) *visitor {
 	var messages, emails, calls int64
 	if user != nil {
 		messages = user.Stats.Messages

server/webpush_store.go

@@ -3,11 +3,11 @@ package server
 import (
 	"database/sql"
 	"errors"
-	"heckel.io/ntfy/v2/util"
 	"net/netip"
+	"strings"
 	"time"
 
-	_ "github.com/mattn/go-sqlite3" // SQLite driver
+	"heckel.io/ntfy/v2/util"
 )
 
 const (
@@ -22,126 +22,49 @@ var (
 	errWebPushUserIDCannotBeEmpty  = errors.New("user ID cannot be empty")
 )
 
-const (
-	createWebPushSubscriptionsTableQuery = `
-		BEGIN;
-		CREATE TABLE IF NOT EXISTS subscription (
-			id TEXT PRIMARY KEY,
-			endpoint TEXT NOT NULL,
-			key_auth TEXT NOT NULL,
-			key_p256dh TEXT NOT NULL,
-			user_id TEXT NOT NULL,		
-			subscriber_ip TEXT NOT NULL,
-			updated_at INT NOT NULL,
-			warned_at INT NOT NULL DEFAULT 0
-		);
-		CREATE UNIQUE INDEX IF NOT EXISTS idx_endpoint ON subscription (endpoint);
-		CREATE INDEX IF NOT EXISTS idx_subscriber_ip ON subscription (subscriber_ip);
-		CREATE TABLE IF NOT EXISTS subscription_topic (
-			subscription_id TEXT NOT NULL,
-			topic TEXT NOT NULL,
-			PRIMARY KEY (subscription_id, topic),
-			FOREIGN KEY (subscription_id) REFERENCES subscription (id) ON DELETE CASCADE
-		);
-		CREATE INDEX IF NOT EXISTS idx_topic ON subscription_topic (topic);
-		CREATE TABLE IF NOT EXISTS schemaVersion (
-			id INT PRIMARY KEY,
-			version INT NOT NULL
-		);			
-		COMMIT;
-	`
-	builtinStartupQueries = `
-		PRAGMA foreign_keys = ON;
-	`
+// WebPushStore is an interface for storing web push subscriptions
+type WebPushStore interface {
+	UpsertSubscription(endpoint string, auth, p256dh, userID string, subscriberIP netip.Addr, topics []string) error
+	SubscriptionsForTopic(topic string) ([]*webPushSubscription, error)
+	SubscriptionsExpiring(warnAfter time.Duration) ([]*webPushSubscription, error)
+	MarkExpiryWarningSent(subscriptions []*webPushSubscription) error
+	RemoveSubscriptionsByEndpoint(endpoint string) error
+	RemoveSubscriptionsByUserID(userID string) error
+	RemoveExpiredSubscriptions(expireAfter time.Duration) error
+	DB() *sql.DB
+	Close() error
+}
 
-	selectWebPushSubscriptionIDByEndpoint        = `SELECT id FROM subscription WHERE endpoint = ?`
-	selectWebPushSubscriptionCountBySubscriberIP = `SELECT COUNT(*) FROM subscription WHERE subscriber_ip = ?`
-	selectWebPushSubscriptionsForTopicQuery      = `
-		SELECT id, endpoint, key_auth, key_p256dh, user_id
-		FROM subscription_topic st
-		JOIN subscription s ON s.id = st.subscription_id
-		WHERE st.topic = ?
-		ORDER BY endpoint
-	`
-	selectWebPushSubscriptionsExpiringSoonQuery = `
-		SELECT id, endpoint, key_auth, key_p256dh, user_id 
-		FROM subscription 
-		WHERE warned_at = 0 AND updated_at <= ?
-	`
-	insertWebPushSubscriptionQuery = `
-		INSERT INTO subscription (id, endpoint, key_auth, key_p256dh, user_id, subscriber_ip, updated_at, warned_at)
-		VALUES (?, ?, ?, ?, ?, ?, ?, ?)
-		ON CONFLICT (endpoint) 
-		DO UPDATE SET key_auth = excluded.key_auth, key_p256dh = excluded.key_p256dh, user_id = excluded.user_id, subscriber_ip = excluded.subscriber_ip, updated_at = excluded.updated_at, warned_at = excluded.warned_at
-	`
-	updateWebPushSubscriptionWarningSentQuery = `UPDATE subscription SET warned_at = ? WHERE id = ?`
-	deleteWebPushSubscriptionByEndpointQuery  = `DELETE FROM subscription WHERE endpoint = ?`
-	deleteWebPushSubscriptionByUserIDQuery    = `DELETE FROM subscription WHERE user_id = ?`
-	deleteWebPushSubscriptionByAgeQuery       = `DELETE FROM subscription WHERE updated_at <= ?` // Full table scan!
-
-	insertWebPushSubscriptionTopicQuery               = `INSERT INTO subscription_topic (subscription_id, topic) VALUES (?, ?)`
-	deleteWebPushSubscriptionTopicAllQuery            = `DELETE FROM subscription_topic WHERE subscription_id = ?`
-	deleteWebPushSubscriptionTopicWithoutSubscription = `DELETE FROM subscription_topic WHERE subscription_id NOT IN (SELECT id FROM subscription)`
-)
-
-// Schema management queries
-const (
-	currentWebPushSchemaVersion     = 1
-	insertWebPushSchemaVersion      = `INSERT INTO schemaVersion VALUES (1, ?)`
-	selectWebPushSchemaVersionQuery = `SELECT version FROM schemaVersion WHERE id = 1`
-)
+// webPushQueries holds all the SQL queries used by webPushStore
+type webPushQueries struct {
+	selectSubscriptionIDByEndpoint        string
+	selectSubscriptionCountBySubscriberIP string
+	selectSubscriptionsForTopic           string
+	selectSubscriptionsExpiringSoon       string
+	insertSubscription                    string
+	updateSubscriptionWarningSent         string
+	deleteSubscriptionByEndpoint          string
+	deleteSubscriptionByUserID            string
+	deleteSubscriptionByAge               string
+	insertSubscriptionTopic               string
+	deleteSubscriptionTopicAll            string
+	deleteSubscriptionTopicWithoutSub     string
+}
 
 type webPushStore struct {
-	db *sql.DB
+	db      *sql.DB
+	queries *webPushQueries
 }
 
-func newWebPushStore(filename, startupQueries string) (*webPushStore, error) {
-	db, err := sql.Open("sqlite3", filename)
-	if err != nil {
-		return nil, err
+// newWebPushStore creates a new webPushStore based on the connection string
+func newWebPushStore(filename, startupQueries string) (WebPushStore, error) {
+	if strings.HasPrefix(filename, "postgres:") {
+		return newPgWebPushStore(strings.TrimPrefix(filename, "postgres:"), startupQueries)
 	}
-	if err := setupWebPushDB(db); err != nil {
-		return nil, err
-	}
-	if err := runWebPushStartupQueries(db, startupQueries); err != nil {
-		return nil, err
-	}
-	return &webPushStore{
-		db: db,
-	}, nil
+	return newSqliteWebPushStore(filename, startupQueries)
 }
 
-func setupWebPushDB(db *sql.DB) error {
-	// If 'schemaVersion' table does not exist, this must be a new database
-	rows, err := db.Query(selectWebPushSchemaVersionQuery)
-	if err != nil {
-		return setupNewWebPushDB(db)
-	}
-	return rows.Close()
-}
-
-func setupNewWebPushDB(db *sql.DB) error {
-	if _, err := db.Exec(createWebPushSubscriptionsTableQuery); err != nil {
-		return err
-	}
-	if _, err := db.Exec(insertWebPushSchemaVersion, currentWebPushSchemaVersion); err != nil {
-		return err
-	}
-	return nil
-}
-
-func runWebPushStartupQueries(db *sql.DB, startupQueries string) error {
-	if _, err := db.Exec(startupQueries); err != nil {
-		return err
-	}
-	if _, err := db.Exec(builtinStartupQueries); err != nil {
-		return err
-	}
-	return nil
-}
-
-// UpsertSubscription adds or updates Web Push subscriptions for the given topics and user ID. It always first deletes all
-// existing entries for a given endpoint.
+// UpsertSubscription adds or updates Web Push subscriptions for the given topics and user ID
 func (c *webPushStore) UpsertSubscription(endpoint string, auth, p256dh, userID string, subscriberIP netip.Addr, topics []string) error {
 	tx, err := c.db.Begin()
 	if err != nil {
@@ -149,7 +72,7 @@ func (c *webPushStore) UpsertSubscription(endpoint string, auth, p256dh, userID
 	}
 	defer tx.Rollback()
 	// Read number of subscriptions for subscriber IP address
-	rowsCount, err := tx.Query(selectWebPushSubscriptionCountBySubscriberIP, subscriberIP.String())
+	rowsCount, err := tx.Query(c.queries.selectSubscriptionCountBySubscriberIP, subscriberIP.String())
 	if err != nil {
 		return err
 	}
@@ -165,7 +88,7 @@ func (c *webPushStore) UpsertSubscription(endpoint string, auth, p256dh, userID
 		return err
 	}
 	// Read existing subscription ID for endpoint (or create new ID)
-	rows, err := tx.Query(selectWebPushSubscriptionIDByEndpoint, endpoint)
+	rows, err := tx.Query(c.queries.selectSubscriptionIDByEndpoint, endpoint)
 	if err != nil {
 		return err
 	}
@@ -186,15 +109,15 @@ func (c *webPushStore) UpsertSubscription(endpoint string, auth, p256dh, userID
 	}
 	// Insert or update subscription
 	updatedAt, warnedAt := time.Now().Unix(), 0
-	if _, err = tx.Exec(insertWebPushSubscriptionQuery, subscriptionID, endpoint, auth, p256dh, userID, subscriberIP.String(), updatedAt, warnedAt); err != nil {
+	if _, err = tx.Exec(c.queries.insertSubscription, subscriptionID, endpoint, auth, p256dh, userID, subscriberIP.String(), updatedAt, warnedAt); err != nil {
 		return err
 	}
 	// Replace all subscription topics
-	if _, err := tx.Exec(deleteWebPushSubscriptionTopicAllQuery, subscriptionID); err != nil {
+	if _, err := tx.Exec(c.queries.deleteSubscriptionTopicAll, subscriptionID); err != nil {
 		return err
 	}
 	for _, topic := range topics {
-		if _, err = tx.Exec(insertWebPushSubscriptionTopicQuery, subscriptionID, topic); err != nil {
+		if _, err = tx.Exec(c.queries.insertSubscriptionTopic, subscriptionID, topic); err != nil {
 			return err
 		}
 	}
@@ -203,7 +126,7 @@ func (c *webPushStore) UpsertSubscription(endpoint string, auth, p256dh, userID
 
 // SubscriptionsForTopic returns all subscriptions for the given topic
 func (c *webPushStore) SubscriptionsForTopic(topic string) ([]*webPushSubscription, error) {
-	rows, err := c.db.Query(selectWebPushSubscriptionsForTopicQuery, topic)
+	rows, err := c.db.Query(c.queries.selectSubscriptionsForTopic, topic)
 	if err != nil {
 		return nil, err
 	}
@@ -213,7 +136,7 @@ func (c *webPushStore) SubscriptionsForTopic(topic string) ([]*webPushSubscripti
 
 // SubscriptionsExpiring returns all subscriptions that have not been updated for a given time period
 func (c *webPushStore) SubscriptionsExpiring(warnAfter time.Duration) ([]*webPushSubscription, error) {
-	rows, err := c.db.Query(selectWebPushSubscriptionsExpiringSoonQuery, time.Now().Add(-warnAfter).Unix())
+	rows, err := c.db.Query(c.queries.selectSubscriptionsExpiringSoon, time.Now().Add(-warnAfter).Unix())
 	if err != nil {
 		return nil, err
 	}
@@ -229,7 +152,7 @@ func (c *webPushStore) MarkExpiryWarningSent(subscriptions []*webPushSubscriptio
 	}
 	defer tx.Rollback()
 	for _, subscription := range subscriptions {
-		if _, err := tx.Exec(updateWebPushSubscriptionWarningSentQuery, time.Now().Unix(), subscription.ID); err != nil {
+		if _, err := tx.Exec(c.queries.updateSubscriptionWarningSent, time.Now().Unix(), subscription.ID); err != nil {
 			return err
 		}
 	}
@@ -256,7 +179,7 @@ func (c *webPushStore) subscriptionsFromRows(rows *sql.Rows) ([]*webPushSubscrip
 
 // RemoveSubscriptionsByEndpoint removes the subscription for the given endpoint
 func (c *webPushStore) RemoveSubscriptionsByEndpoint(endpoint string) error {
-	_, err := c.db.Exec(deleteWebPushSubscriptionByEndpointQuery, endpoint)
+	_, err := c.db.Exec(c.queries.deleteSubscriptionByEndpoint, endpoint)
 	return err
 }
 
@@ -265,20 +188,25 @@ func (c *webPushStore) RemoveSubscriptionsByUserID(userID string) error {
 	if userID == "" {
 		return errWebPushUserIDCannotBeEmpty
 	}
-	_, err := c.db.Exec(deleteWebPushSubscriptionByUserIDQuery, userID)
+	_, err := c.db.Exec(c.queries.deleteSubscriptionByUserID, userID)
 	return err
 }
 
 // RemoveExpiredSubscriptions removes all subscriptions that have not been updated for a given time period
 func (c *webPushStore) RemoveExpiredSubscriptions(expireAfter time.Duration) error {
-	_, err := c.db.Exec(deleteWebPushSubscriptionByAgeQuery, time.Now().Add(-expireAfter).Unix())
+	_, err := c.db.Exec(c.queries.deleteSubscriptionByAge, time.Now().Add(-expireAfter).Unix())
 	if err != nil {
 		return err
 	}
-	_, err = c.db.Exec(deleteWebPushSubscriptionTopicWithoutSubscription)
+	_, err = c.db.Exec(c.queries.deleteSubscriptionTopicWithoutSub)
 	return err
 }
 
+// DB returns the underlying database connection (for testing)
+func (c *webPushStore) DB() *sql.DB {
+	return c.db
+}
+
 // Close closes the underlying database connection
 func (c *webPushStore) Close() error {
 	return c.db.Close()

server/webpush_store_pg.go

@@ -0,0 +1,130 @@
+package server
+
+import (
+	"database/sql"
+	"fmt"
+
+	_ "github.com/jackc/pgx/v5/stdlib" // PostgreSQL driver
+)
+
+// PostgreSQL-specific queries
+const (
+	pgCreateWebPushSubscriptionsTableQuery = `
+		BEGIN;
+		CREATE TABLE IF NOT EXISTS subscription (
+			id TEXT PRIMARY KEY,
+			endpoint TEXT NOT NULL,
+			key_auth TEXT NOT NULL,
+			key_p256dh TEXT NOT NULL,
+			user_id TEXT NOT NULL,		
+			subscriber_ip TEXT NOT NULL,
+			updated_at INT NOT NULL,
+			warned_at INT NOT NULL DEFAULT 0
+		);
+		CREATE UNIQUE INDEX IF NOT EXISTS idx_endpoint ON subscription (endpoint);
+		CREATE INDEX IF NOT EXISTS idx_subscriber_ip ON subscription (subscriber_ip);
+		CREATE TABLE IF NOT EXISTS subscription_topic (
+			subscription_id TEXT NOT NULL,
+			topic TEXT NOT NULL,
+			PRIMARY KEY (subscription_id, topic),
+			FOREIGN KEY (subscription_id) REFERENCES subscription (id) ON DELETE CASCADE
+		);
+		CREATE INDEX IF NOT EXISTS idx_topic ON subscription_topic (topic);
+		CREATE TABLE IF NOT EXISTS schema_version (
+			id INT PRIMARY KEY,
+			version INT NOT NULL
+		);			
+		COMMIT;
+	`
+
+	// Schema management queries
+	pgCurrentWebPushSchemaVersion     = 1
+	pgInsertWebPushSchemaVersion      = `INSERT INTO schema_version VALUES (1, $1)`
+	pgSelectWebPushSchemaVersionQuery = `SELECT version FROM schema_version WHERE id = 1`
+)
+
+// PostgreSQL-specific webpush queries
+var pgWebPushQueries = &webPushQueries{
+	selectSubscriptionIDByEndpoint:        `SELECT id FROM subscription WHERE endpoint = $1`,
+	selectSubscriptionCountBySubscriberIP: `SELECT COUNT(*) FROM subscription WHERE subscriber_ip = $1`,
+	selectSubscriptionsForTopic: `
+		SELECT id, endpoint, key_auth, key_p256dh, user_id
+		FROM subscription_topic st
+		JOIN subscription s ON s.id = st.subscription_id
+		WHERE st.topic = $1
+		ORDER BY endpoint
+	`,
+	selectSubscriptionsExpiringSoon: `
+		SELECT id, endpoint, key_auth, key_p256dh, user_id 
+		FROM subscription 
+		WHERE warned_at = 0 AND updated_at <= $1
+	`,
+	insertSubscription: `
+		INSERT INTO subscription (id, endpoint, key_auth, key_p256dh, user_id, subscriber_ip, updated_at, warned_at)
+		VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
+		ON CONFLICT (endpoint) 
+		DO UPDATE SET key_auth = EXCLUDED.key_auth, key_p256dh = EXCLUDED.key_p256dh, user_id = EXCLUDED.user_id, subscriber_ip = EXCLUDED.subscriber_ip, updated_at = EXCLUDED.updated_at, warned_at = EXCLUDED.warned_at
+	`,
+	updateSubscriptionWarningSent:     `UPDATE subscription SET warned_at = $1 WHERE id = $2`,
+	deleteSubscriptionByEndpoint:      `DELETE FROM subscription WHERE endpoint = $1`,
+	deleteSubscriptionByUserID:        `DELETE FROM subscription WHERE user_id = $1`,
+	deleteSubscriptionByAge:           `DELETE FROM subscription WHERE updated_at <= $1`,
+	insertSubscriptionTopic:           `INSERT INTO subscription_topic (subscription_id, topic) VALUES ($1, $2)`,
+	deleteSubscriptionTopicAll:        `DELETE FROM subscription_topic WHERE subscription_id = $1`,
+	deleteSubscriptionTopicWithoutSub: `DELETE FROM subscription_topic WHERE subscription_id NOT IN (SELECT id FROM subscription)`,
+}
+
+func newPgWebPushStore(connStr, startupQueries string) (*webPushStore, error) {
+	db, err := sql.Open("pgx", connStr)
+	if err != nil {
+		return nil, err
+	}
+	if err := db.Ping(); err != nil {
+		return nil, fmt.Errorf("failed to connect to PostgreSQL: %w", err)
+	}
+	if err := setupPgWebPushDB(db); err != nil {
+		return nil, err
+	}
+	if err := runPgWebPushStartupQueries(db, startupQueries); err != nil {
+		return nil, err
+	}
+	return &webPushStore{
+		db:      db,
+		queries: pgWebPushQueries,
+	}, nil
+}
+
+func setupPgWebPushDB(db *sql.DB) error {
+	// If 'schema_version' table does not exist, this must be a new database
+	rows, err := db.Query(pgSelectWebPushSchemaVersionQuery)
+	if err != nil {
+		return setupNewPgWebPushDB(db)
+	}
+	defer rows.Close()
+
+	// If table exists but no rows, also create new
+	if !rows.Next() {
+		return setupNewPgWebPushDB(db)
+	}
+	return nil
+}
+
+func setupNewPgWebPushDB(db *sql.DB) error {
+	if _, err := db.Exec(pgCreateWebPushSubscriptionsTableQuery); err != nil {
+		return err
+	}
+	if _, err := db.Exec(pgInsertWebPushSchemaVersion, pgCurrentWebPushSchemaVersion); err != nil {
+		return err
+	}
+	return nil
+}
+
+func runPgWebPushStartupQueries(db *sql.DB, startupQueries string) error {
+	if startupQueries != "" {
+		if _, err := db.Exec(startupQueries); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+

server/webpush_store_sqlite.go

@@ -0,0 +1,126 @@
+package server
+
+import (
+	"database/sql"
+
+	_ "github.com/mattn/go-sqlite3" // SQLite driver
+)
+
+// SQLite-specific queries
+const (
+	sqliteCreateWebPushSubscriptionsTableQuery = `
+		BEGIN;
+		CREATE TABLE IF NOT EXISTS subscription (
+			id TEXT PRIMARY KEY,
+			endpoint TEXT NOT NULL,
+			key_auth TEXT NOT NULL,
+			key_p256dh TEXT NOT NULL,
+			user_id TEXT NOT NULL,		
+			subscriber_ip TEXT NOT NULL,
+			updated_at INT NOT NULL,
+			warned_at INT NOT NULL DEFAULT 0
+		);
+		CREATE UNIQUE INDEX IF NOT EXISTS idx_endpoint ON subscription (endpoint);
+		CREATE INDEX IF NOT EXISTS idx_subscriber_ip ON subscription (subscriber_ip);
+		CREATE TABLE IF NOT EXISTS subscription_topic (
+			subscription_id TEXT NOT NULL,
+			topic TEXT NOT NULL,
+			PRIMARY KEY (subscription_id, topic),
+			FOREIGN KEY (subscription_id) REFERENCES subscription (id) ON DELETE CASCADE
+		);
+		CREATE INDEX IF NOT EXISTS idx_topic ON subscription_topic (topic);
+		CREATE TABLE IF NOT EXISTS schemaVersion (
+			id INT PRIMARY KEY,
+			version INT NOT NULL
+		);			
+		COMMIT;
+	`
+	sqliteWebPushBuiltinStartupQueries = `
+		PRAGMA foreign_keys = ON;
+	`
+
+	// Schema management queries
+	sqliteCurrentWebPushSchemaVersion     = 1
+	sqliteInsertWebPushSchemaVersion      = `INSERT INTO schemaVersion VALUES (1, ?)`
+	sqliteSelectWebPushSchemaVersionQuery = `SELECT version FROM schemaVersion WHERE id = 1`
+)
+
+// SQLite-specific webpush queries
+var sqliteWebPushQueries = &webPushQueries{
+	selectSubscriptionIDByEndpoint:        `SELECT id FROM subscription WHERE endpoint = ?`,
+	selectSubscriptionCountBySubscriberIP: `SELECT COUNT(*) FROM subscription WHERE subscriber_ip = ?`,
+	selectSubscriptionsForTopic: `
+		SELECT id, endpoint, key_auth, key_p256dh, user_id
+		FROM subscription_topic st
+		JOIN subscription s ON s.id = st.subscription_id
+		WHERE st.topic = ?
+		ORDER BY endpoint
+	`,
+	selectSubscriptionsExpiringSoon: `
+		SELECT id, endpoint, key_auth, key_p256dh, user_id 
+		FROM subscription 
+		WHERE warned_at = 0 AND updated_at <= ?
+	`,
+	insertSubscription: `
+		INSERT INTO subscription (id, endpoint, key_auth, key_p256dh, user_id, subscriber_ip, updated_at, warned_at)
+		VALUES (?, ?, ?, ?, ?, ?, ?, ?)
+		ON CONFLICT (endpoint) 
+		DO UPDATE SET key_auth = excluded.key_auth, key_p256dh = excluded.key_p256dh, user_id = excluded.user_id, subscriber_ip = excluded.subscriber_ip, updated_at = excluded.updated_at, warned_at = excluded.warned_at
+	`,
+	updateSubscriptionWarningSent:       `UPDATE subscription SET warned_at = ? WHERE id = ?`,
+	deleteSubscriptionByEndpoint:        `DELETE FROM subscription WHERE endpoint = ?`,
+	deleteSubscriptionByUserID:          `DELETE FROM subscription WHERE user_id = ?`,
+	deleteSubscriptionByAge:             `DELETE FROM subscription WHERE updated_at <= ?`,
+	insertSubscriptionTopic:             `INSERT INTO subscription_topic (subscription_id, topic) VALUES (?, ?)`,
+	deleteSubscriptionTopicAll:          `DELETE FROM subscription_topic WHERE subscription_id = ?`,
+	deleteSubscriptionTopicWithoutSub:   `DELETE FROM subscription_topic WHERE subscription_id NOT IN (SELECT id FROM subscription)`,
+}
+
+func newSqliteWebPushStore(filename, startupQueries string) (*webPushStore, error) {
+	db, err := sql.Open("sqlite3", filename)
+	if err != nil {
+		return nil, err
+	}
+	if err := setupSqliteWebPushDB(db); err != nil {
+		return nil, err
+	}
+	if err := runSqliteWebPushStartupQueries(db, startupQueries); err != nil {
+		return nil, err
+	}
+	return &webPushStore{
+		db:      db,
+		queries: sqliteWebPushQueries,
+	}, nil
+}
+
+func setupSqliteWebPushDB(db *sql.DB) error {
+	// If 'schemaVersion' table does not exist, this must be a new database
+	rows, err := db.Query(sqliteSelectWebPushSchemaVersionQuery)
+	if err != nil {
+		return setupNewSqliteWebPushDB(db)
+	}
+	return rows.Close()
+}
+
+func setupNewSqliteWebPushDB(db *sql.DB) error {
+	if _, err := db.Exec(sqliteCreateWebPushSubscriptionsTableQuery); err != nil {
+		return err
+	}
+	if _, err := db.Exec(sqliteInsertWebPushSchemaVersion, sqliteCurrentWebPushSchemaVersion); err != nil {
+		return err
+	}
+	return nil
+}
+
+func runSqliteWebPushStartupQueries(db *sql.DB, startupQueries string) error {
+	if startupQueries != "" {
+		if _, err := db.Exec(startupQueries); err != nil {
+			return err
+		}
+	}
+	if _, err := db.Exec(sqliteWebPushBuiltinStartupQueries); err != nil {
+		return err
+	}
+	return nil
+}
+

server/webpush_store_test.go

@@ -134,7 +134,7 @@ func TestWebPushStore_MarkExpiryWarningSent(t *testing.T) {
 	// Mark them as warning sent
 	require.Nil(t, webPush.MarkExpiryWarningSent(subs))
 
-	rows, err := webPush.db.Query("SELECT endpoint FROM subscription WHERE warned_at > 0")
+	rows, err := webPush.DB().Query("SELECT endpoint FROM subscription WHERE warned_at > 0")
 	require.Nil(t, err)
 	defer rows.Close()
 	var endpoint string
@@ -156,7 +156,7 @@ func TestWebPushStore_SubscriptionsExpiring(t *testing.T) {
 	require.Len(t, subs, 1)
 
 	// Fake-mark them as soon-to-expire
-	_, err = webPush.db.Exec("UPDATE subscription SET updated_at = ? WHERE endpoint = ?", time.Now().Add(-8*24*time.Hour).Unix(), testWebPushEndpoint)
+	_, err = webPush.DB().Exec("UPDATE subscription SET updated_at = ? WHERE endpoint = ?", time.Now().Add(-8*24*time.Hour).Unix(), testWebPushEndpoint)
 	require.Nil(t, err)
 
 	// Should not be cleaned up yet
@@ -180,7 +180,7 @@ func TestWebPushStore_RemoveExpiredSubscriptions(t *testing.T) {
 	require.Len(t, subs, 1)
 
 	// Fake-mark them as expired
-	_, err = webPush.db.Exec("UPDATE subscription SET updated_at = ? WHERE endpoint = ?", time.Now().Add(-10*24*time.Hour).Unix(), testWebPushEndpoint)
+	_, err = webPush.DB().Exec("UPDATE subscription SET updated_at = ? WHERE endpoint = ?", time.Now().Add(-10*24*time.Hour).Unix(), testWebPushEndpoint)
 	require.Nil(t, err)
 
 	// Run expiration
@@ -192,7 +192,7 @@ func TestWebPushStore_RemoveExpiredSubscriptions(t *testing.T) {
 	require.Len(t, subs, 0)
 }
 
-func newTestWebPushStore(t *testing.T) *webPushStore {
+func newTestWebPushStore(t *testing.T) WebPushStore {
 	webPush, err := newWebPushStore(filepath.Join(t.TempDir(), "webpush.db"), "")
 	require.Nil(t, err)
 	return webPush

user/manager.go

@@ -6,17 +6,17 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"net/netip"
+	"slices"
+	"strings"
+	"sync"
+	"time"
+
 	"github.com/mattn/go-sqlite3"
 	"golang.org/x/crypto/bcrypt"
 	"heckel.io/ntfy/v2/log"
 	"heckel.io/ntfy/v2/payments"
 	"heckel.io/ntfy/v2/util"
-	"net/netip"
-	"path/filepath"
-	"slices"
-	"strings"
-	"sync"
-	"time"
 )
 
 const (
@@ -43,100 +43,10 @@ const (
 var (
 	errNoTokenProvided    = errors.New("no token provided")
 	errTopicOwnedByOthers = errors.New("topic owned by others")
-	errNoRows             = errors.New("no rows found")
 )
 
 // Manager-related queries
 const (
-	createTablesQueries = `
-		BEGIN;
-		CREATE TABLE IF NOT EXISTS tier (
-			id TEXT PRIMARY KEY,
-			code TEXT NOT NULL,
-			name TEXT NOT NULL,
-			messages_limit INT NOT NULL,
-			messages_expiry_duration INT NOT NULL,
-			emails_limit INT NOT NULL,
-			calls_limit INT NOT NULL,
-			reservations_limit INT NOT NULL,
-			attachment_file_size_limit INT NOT NULL,
-			attachment_total_size_limit INT NOT NULL,
-			attachment_expiry_duration INT NOT NULL,
-			attachment_bandwidth_limit INT NOT NULL,
-			stripe_monthly_price_id TEXT,
-			stripe_yearly_price_id TEXT
-		);
-		CREATE UNIQUE INDEX idx_tier_code ON tier (code);
-		CREATE UNIQUE INDEX idx_tier_stripe_monthly_price_id ON tier (stripe_monthly_price_id);
-		CREATE UNIQUE INDEX idx_tier_stripe_yearly_price_id ON tier (stripe_yearly_price_id);
-		CREATE TABLE IF NOT EXISTS user (
-		    id TEXT PRIMARY KEY,
-			tier_id TEXT,
-			user TEXT NOT NULL,
-			pass TEXT NOT NULL,
-			role TEXT CHECK (role IN ('anonymous', 'admin', 'user')) NOT NULL,
-			prefs JSON NOT NULL DEFAULT '{}',
-			sync_topic TEXT NOT NULL,
-			provisioned INT NOT NULL,
-			stats_messages INT NOT NULL DEFAULT (0),
-			stats_emails INT NOT NULL DEFAULT (0),
-			stats_calls INT NOT NULL DEFAULT (0),
-			stripe_customer_id TEXT,
-			stripe_subscription_id TEXT,
-			stripe_subscription_status TEXT,
-			stripe_subscription_interval TEXT,
-			stripe_subscription_paid_until INT,
-			stripe_subscription_cancel_at INT,
-			created INT NOT NULL,
-			deleted INT,
-		    FOREIGN KEY (tier_id) REFERENCES tier (id)
-		);
-		CREATE UNIQUE INDEX idx_user ON user (user);
-		CREATE UNIQUE INDEX idx_user_stripe_customer_id ON user (stripe_customer_id);
-		CREATE UNIQUE INDEX idx_user_stripe_subscription_id ON user (stripe_subscription_id);
-		CREATE TABLE IF NOT EXISTS user_access (
-			user_id TEXT NOT NULL,
-			topic TEXT NOT NULL,
-			read INT NOT NULL,
-			write INT NOT NULL,
-			owner_user_id INT,
-			provisioned INT NOT NULL,
-			PRIMARY KEY (user_id, topic),
-			FOREIGN KEY (user_id) REFERENCES user (id) ON DELETE CASCADE,
-		    FOREIGN KEY (owner_user_id) REFERENCES user (id) ON DELETE CASCADE
-		);
-		CREATE TABLE IF NOT EXISTS user_token (
-			user_id TEXT NOT NULL,
-			token TEXT NOT NULL,
-			label TEXT NOT NULL,
-			last_access INT NOT NULL,
-			last_origin TEXT NOT NULL,
-			expires INT NOT NULL,
-			provisioned INT NOT NULL,
-			PRIMARY KEY (user_id, token),
-			FOREIGN KEY (user_id) REFERENCES user (id) ON DELETE CASCADE
-		);
-		CREATE UNIQUE INDEX idx_user_token ON user_token (token);
-		CREATE TABLE IF NOT EXISTS user_phone (
-			user_id TEXT NOT NULL,
-			phone_number TEXT NOT NULL,
-			PRIMARY KEY (user_id, phone_number),
-			FOREIGN KEY (user_id) REFERENCES user (id) ON DELETE CASCADE
-		);
-		CREATE TABLE IF NOT EXISTS schemaVersion (
-			id INT PRIMARY KEY,
-			version INT NOT NULL
-		);
-		INSERT INTO user (id, user, pass, role, sync_topic, provisioned, created)
-		VALUES ('` + everyoneID + `', '*', '', 'anonymous', '', false, UNIXEPOCH())
-		ON CONFLICT (id) DO NOTHING;
-		COMMIT;
-	`
-
-	builtinStartupQueries = `
-		PRAGMA foreign_keys = ON;
-	`
-
 	selectUserByIDQuery = `
 		SELECT u.id, u.user, u.pass, u.role, u.prefs, u.sync_topic, u.provisioned, u.stats_messages, u.stats_emails, u.stats_calls, u.stripe_customer_id, u.stripe_subscription_id, u.stripe_subscription_status, u.stripe_subscription_interval, u.stripe_subscription_paid_until, u.stripe_subscription_cancel_at, deleted, t.id, t.code, t.name, t.messages_limit, t.messages_expiry_duration, t.emails_limit, t.calls_limit, t.reservations_limit, t.attachment_file_size_limit, t.attachment_total_size_limit, t.attachment_expiry_duration, t.attachment_bandwidth_limit, t.stripe_monthly_price_id, t.stripe_yearly_price_id
 		FROM user u
@@ -326,229 +236,6 @@ const (
 	`
 )
 
-// Schema management queries
-const (
-	currentSchemaVersion     = 6
-	insertSchemaVersion      = `INSERT INTO schemaVersion VALUES (1, ?)`
-	updateSchemaVersion      = `UPDATE schemaVersion SET version = ? WHERE id = 1`
-	selectSchemaVersionQuery = `SELECT version FROM schemaVersion WHERE id = 1`
-
-	// 1 -> 2 (complex migration!)
-	migrate1To2CreateTablesQueries = `
-		ALTER TABLE user RENAME TO user_old;
-		CREATE TABLE IF NOT EXISTS tier (
-			id TEXT PRIMARY KEY,
-			code TEXT NOT NULL,
-			name TEXT NOT NULL,
-			messages_limit INT NOT NULL,
-			messages_expiry_duration INT NOT NULL,
-			emails_limit INT NOT NULL,
-			reservations_limit INT NOT NULL,
-			attachment_file_size_limit INT NOT NULL,
-			attachment_total_size_limit INT NOT NULL,
-			attachment_expiry_duration INT NOT NULL,
-			attachment_bandwidth_limit INT NOT NULL,
-			stripe_price_id TEXT
-		);
-		CREATE UNIQUE INDEX idx_tier_code ON tier (code);
-		CREATE UNIQUE INDEX idx_tier_price_id ON tier (stripe_price_id);
-		CREATE TABLE IF NOT EXISTS user (
-		    id TEXT PRIMARY KEY,
-			tier_id TEXT,
-			user TEXT NOT NULL,
-			pass TEXT NOT NULL,
-			role TEXT CHECK (role IN ('anonymous', 'admin', 'user')) NOT NULL,
-			prefs JSON NOT NULL DEFAULT '{}',
-			sync_topic TEXT NOT NULL,
-			stats_messages INT NOT NULL DEFAULT (0),
-			stats_emails INT NOT NULL DEFAULT (0),
-			stripe_customer_id TEXT,
-			stripe_subscription_id TEXT,
-			stripe_subscription_status TEXT,
-			stripe_subscription_paid_until INT,
-			stripe_subscription_cancel_at INT,
-			created INT NOT NULL,
-			deleted INT,
-		    FOREIGN KEY (tier_id) REFERENCES tier (id)
-		);
-		CREATE UNIQUE INDEX idx_user ON user (user);
-		CREATE UNIQUE INDEX idx_user_stripe_customer_id ON user (stripe_customer_id);
-		CREATE UNIQUE INDEX idx_user_stripe_subscription_id ON user (stripe_subscription_id);
-		CREATE TABLE IF NOT EXISTS user_access (
-			user_id TEXT NOT NULL,
-			topic TEXT NOT NULL,
-			read INT NOT NULL,
-			write INT NOT NULL,
-			owner_user_id INT,
-			PRIMARY KEY (user_id, topic),
-			FOREIGN KEY (user_id) REFERENCES user (id) ON DELETE CASCADE,
-		    FOREIGN KEY (owner_user_id) REFERENCES user (id) ON DELETE CASCADE
-		);
-		CREATE TABLE IF NOT EXISTS user_token (
-			user_id TEXT NOT NULL,
-			token TEXT NOT NULL,
-			label TEXT NOT NULL,
-			last_access INT NOT NULL,
-			last_origin TEXT NOT NULL,
-			expires INT NOT NULL,
-			PRIMARY KEY (user_id, token),
-			FOREIGN KEY (user_id) REFERENCES user (id) ON DELETE CASCADE
-		);
-		CREATE TABLE IF NOT EXISTS schemaVersion (
-			id INT PRIMARY KEY,
-			version INT NOT NULL
-		);
-		INSERT INTO user (id, user, pass, role, sync_topic, created)
-		VALUES ('u_everyone', '*', '', 'anonymous', '', UNIXEPOCH())
-		ON CONFLICT (id) DO NOTHING;
-	`
-	migrate1To2SelectAllOldUsernamesNoTx = `SELECT user FROM user_old`
-	migrate1To2InsertUserNoTx            = `
-		INSERT INTO user (id, user, pass, role, sync_topic, created)
-		SELECT ?, user, pass, role, ?, UNIXEPOCH() FROM user_old WHERE user = ?
-	`
-	migrate1To2InsertFromOldTablesAndDropNoTx = `
-		INSERT INTO user_access (user_id, topic, read, write)
-		SELECT u.id, a.topic, a.read, a.write
-		FROM user u
-	 	JOIN access a ON u.user = a.user;
-
-		DROP TABLE access;
-		DROP TABLE user_old;
-	`
-
-	// 2 -> 3
-	migrate2To3UpdateQueries = `
-		ALTER TABLE user ADD COLUMN stripe_subscription_interval TEXT;
-		ALTER TABLE tier RENAME COLUMN stripe_price_id TO stripe_monthly_price_id;
-		ALTER TABLE tier ADD COLUMN stripe_yearly_price_id TEXT;
-		DROP INDEX IF EXISTS idx_tier_price_id;
-		CREATE UNIQUE INDEX idx_tier_stripe_monthly_price_id ON tier (stripe_monthly_price_id);
-		CREATE UNIQUE INDEX idx_tier_stripe_yearly_price_id ON tier (stripe_yearly_price_id);
-	`
-
-	// 3 -> 4
-	migrate3To4UpdateQueries = `
-		ALTER TABLE tier ADD COLUMN calls_limit INT NOT NULL DEFAULT (0);
-		ALTER TABLE user ADD COLUMN stats_calls INT NOT NULL DEFAULT (0);
-		CREATE TABLE IF NOT EXISTS user_phone (
-			user_id TEXT NOT NULL,
-			phone_number TEXT NOT NULL,
-			PRIMARY KEY (user_id, phone_number),
-			FOREIGN KEY (user_id) REFERENCES user (id) ON DELETE CASCADE
-		);
-	`
-
-	// 4 -> 5
-	migrate4To5UpdateQueries = `
-		UPDATE user_access SET topic = REPLACE(topic, '_', '\_');
-	`
-
-	// 5 -> 6
-	migrate5To6UpdateQueries = `
-		PRAGMA foreign_keys=off;
-
-		-- Alter user table: Add provisioned column
-		ALTER TABLE user RENAME TO user_old;
-		CREATE TABLE IF NOT EXISTS user (
-		    id TEXT PRIMARY KEY,
-			tier_id TEXT,
-			user TEXT NOT NULL,
-			pass TEXT NOT NULL,
-			role TEXT CHECK (role IN ('anonymous', 'admin', 'user')) NOT NULL,
-			prefs JSON NOT NULL DEFAULT '{}',
-			sync_topic TEXT NOT NULL,
-			provisioned INT NOT NULL,
-			stats_messages INT NOT NULL DEFAULT (0),
-			stats_emails INT NOT NULL DEFAULT (0),
-			stats_calls INT NOT NULL DEFAULT (0),
-			stripe_customer_id TEXT,
-			stripe_subscription_id TEXT,
-			stripe_subscription_status TEXT,
-			stripe_subscription_interval TEXT,
-			stripe_subscription_paid_until INT,
-			stripe_subscription_cancel_at INT,
-			created INT NOT NULL,
-			deleted INT,
-		    FOREIGN KEY (tier_id) REFERENCES tier (id)
-		);
-		INSERT INTO user
-		SELECT
-		    id,
-		    tier_id,
-		    user,
-		    pass,
-		    role,
-		    prefs,
-		    sync_topic,
-		    0, -- provisioned
-		    stats_messages,
-		    stats_emails,
-		    stats_calls,
-		    stripe_customer_id,
-		    stripe_subscription_id,
-		    stripe_subscription_status,
-		    stripe_subscription_interval,
-		    stripe_subscription_paid_until,
-		    stripe_subscription_cancel_at,
-		    created,
-		    deleted
-		FROM user_old;
-		DROP TABLE user_old;
-
-		-- Alter user_access table: Add provisioned column
-		ALTER TABLE user_access RENAME TO user_access_old;
-		CREATE TABLE user_access (
-			user_id TEXT NOT NULL,
-			topic TEXT NOT NULL,
-			read INT NOT NULL,
-			write INT NOT NULL,
-			owner_user_id INT,
-			provisioned INTEGER NOT NULL,
-			PRIMARY KEY (user_id, topic),
-			FOREIGN KEY (user_id) REFERENCES user (id) ON DELETE CASCADE,
-			FOREIGN KEY (owner_user_id) REFERENCES user (id) ON DELETE CASCADE
-		);
-		INSERT INTO user_access SELECT *, 0 FROM user_access_old;
-		DROP TABLE user_access_old;
-
-		-- Alter user_token table: Add provisioned column
-		ALTER TABLE user_token RENAME TO user_token_old;
-		CREATE TABLE IF NOT EXISTS user_token (
-			user_id TEXT NOT NULL,
-			token TEXT NOT NULL,
-			label TEXT NOT NULL,
-			last_access INT NOT NULL,
-			last_origin TEXT NOT NULL,
-			expires INT NOT NULL,
-			provisioned INT NOT NULL,
-			PRIMARY KEY (user_id, token),
-			FOREIGN KEY (user_id) REFERENCES user (id) ON DELETE CASCADE
-		);
-		INSERT INTO user_token SELECT *, 0 FROM user_token_old;
-		DROP TABLE user_token_old;
-
-		-- Recreate indices
-		CREATE UNIQUE INDEX idx_user ON user (user);
-		CREATE UNIQUE INDEX idx_user_stripe_customer_id ON user (stripe_customer_id);
-		CREATE UNIQUE INDEX idx_user_stripe_subscription_id ON user (stripe_subscription_id);
-		CREATE UNIQUE INDEX idx_user_token ON user_token (token);
-
-		-- Re-enable foreign keys
-		PRAGMA foreign_keys=on;
-	`
-)
-
-var (
-	migrations = map[int]func(db *sql.DB) error{
-		1: migrateFrom1,
-		2: migrateFrom2,
-		3: migrateFrom3,
-		4: migrateFrom4,
-		5: migrateFrom5,
-	}
-)
-
 // Manager is an implementation of Manager. It stores users and access control list
 // in a SQLite database.
 type Manager struct {
@@ -583,28 +270,20 @@ func NewManager(config *Config) (*Manager, error) {
 	if config.QueueWriterInterval.Seconds() <= 0 {
 		config.QueueWriterInterval = DefaultUserStatsQueueWriterInterval
 	}
-	// Check the parent directory of the database file (makes for friendly error messages)
-	parentDir := filepath.Dir(config.Filename)
-	if !util.FileExists(parentDir) {
-		return nil, fmt.Errorf("user database directory %s does not exist or is not accessible", parentDir)
+
+	var manager *Manager
+	var err error
+
+	// Select database backend based on connection string
+	if strings.HasPrefix(config.Filename, "postgres:") {
+		manager, err = newPgManager(config)
+	} else {
+		manager, err = newSqliteManager(config)
 	}
-	// Open DB and run setup queries
-	db, err := sql.Open("sqlite3", config.Filename)
 	if err != nil {
 		return nil, err
 	}
-	if err := setupDB(db); err != nil {
-		return nil, err
-	}
-	if err := runStartupQueries(db, config.StartupQueries); err != nil {
-		return nil, err
-	}
-	manager := &Manager{
-		db:         db,
-		config:     config,
-		statsQueue: make(map[string]*Stats),
-		tokenQueue: make(map[string]*TokenUpdate),
-	}
+
 	if err := manager.maybeProvisionUsersAccessAndTokens(); err != nil {
 		return nil, err
 	}
@@ -1929,173 +1608,6 @@ func unescapeUnderscore(s string) string {
 	return strings.ReplaceAll(s, "\\_", "_")
 }
 
-func runStartupQueries(db *sql.DB, startupQueries string) error {
-	if _, err := db.Exec(startupQueries); err != nil {
-		return err
-	}
-	if _, err := db.Exec(builtinStartupQueries); err != nil {
-		return err
-	}
-	return nil
-}
-
-func setupDB(db *sql.DB) error {
-	// If 'schemaVersion' table does not exist, this must be a new database
-	rowsSV, err := db.Query(selectSchemaVersionQuery)
-	if err != nil {
-		return setupNewDB(db)
-	}
-	defer rowsSV.Close()
-
-	// If 'schemaVersion' table exists, read version and potentially upgrade
-	schemaVersion := 0
-	if !rowsSV.Next() {
-		return errors.New("cannot determine schema version: database file may be corrupt")
-	}
-	if err := rowsSV.Scan(&schemaVersion); err != nil {
-		return err
-	}
-	rowsSV.Close()
-
-	// Do migrations
-	if schemaVersion == currentSchemaVersion {
-		return nil
-	} else if schemaVersion > currentSchemaVersion {
-		return fmt.Errorf("unexpected schema version: version %d is higher than current version %d", schemaVersion, currentSchemaVersion)
-	}
-	for i := schemaVersion; i < currentSchemaVersion; i++ {
-		fn, ok := migrations[i]
-		if !ok {
-			return fmt.Errorf("cannot find migration step from schema version %d to %d", i, i+1)
-		} else if err := fn(db); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
-func setupNewDB(db *sql.DB) error {
-	if _, err := db.Exec(createTablesQueries); err != nil {
-		return err
-	}
-	if _, err := db.Exec(insertSchemaVersion, currentSchemaVersion); err != nil {
-		return err
-	}
-	return nil
-}
-
-func migrateFrom1(db *sql.DB) error {
-	log.Tag(tag).Info("Migrating user database schema: from 1 to 2")
-	tx, err := db.Begin()
-	if err != nil {
-		return err
-	}
-	defer tx.Rollback()
-	// Rename user -> user_old, and create new tables
-	if _, err := tx.Exec(migrate1To2CreateTablesQueries); err != nil {
-		return err
-	}
-	// Insert users from user_old into new user table, with ID and sync_topic
-	rows, err := tx.Query(migrate1To2SelectAllOldUsernamesNoTx)
-	if err != nil {
-		return err
-	}
-	defer rows.Close()
-	usernames := make([]string, 0)
-	for rows.Next() {
-		var username string
-		if err := rows.Scan(&username); err != nil {
-			return err
-		}
-		usernames = append(usernames, username)
-	}
-	if err := rows.Close(); err != nil {
-		return err
-	}
-	for _, username := range usernames {
-		userID := util.RandomStringPrefix(userIDPrefix, userIDLength)
-		syncTopic := util.RandomStringPrefix(syncTopicPrefix, syncTopicLength)
-		if _, err := tx.Exec(migrate1To2InsertUserNoTx, userID, syncTopic, username); err != nil {
-			return err
-		}
-	}
-	// Migrate old "access" table to "user_access" and drop "access" and "user_old"
-	if _, err := tx.Exec(migrate1To2InsertFromOldTablesAndDropNoTx); err != nil {
-		return err
-	}
-	if _, err := tx.Exec(updateSchemaVersion, 2); err != nil {
-		return err
-	}
-	if err := tx.Commit(); err != nil {
-		return err
-	}
-	return nil
-}
-
-func migrateFrom2(db *sql.DB) error {
-	log.Tag(tag).Info("Migrating user database schema: from 2 to 3")
-	tx, err := db.Begin()
-	if err != nil {
-		return err
-	}
-	defer tx.Rollback()
-	if _, err := tx.Exec(migrate2To3UpdateQueries); err != nil {
-		return err
-	}
-	if _, err := tx.Exec(updateSchemaVersion, 3); err != nil {
-		return err
-	}
-	return tx.Commit()
-}
-
-func migrateFrom3(db *sql.DB) error {
-	log.Tag(tag).Info("Migrating user database schema: from 3 to 4")
-	tx, err := db.Begin()
-	if err != nil {
-		return err
-	}
-	defer tx.Rollback()
-	if _, err := tx.Exec(migrate3To4UpdateQueries); err != nil {
-		return err
-	}
-	if _, err := tx.Exec(updateSchemaVersion, 4); err != nil {
-		return err
-	}
-	return tx.Commit()
-}
-
-func migrateFrom4(db *sql.DB) error {
-	log.Tag(tag).Info("Migrating user database schema: from 4 to 5")
-	tx, err := db.Begin()
-	if err != nil {
-		return err
-	}
-	defer tx.Rollback()
-	if _, err := tx.Exec(migrate4To5UpdateQueries); err != nil {
-		return err
-	}
-	if _, err := tx.Exec(updateSchemaVersion, 5); err != nil {
-		return err
-	}
-	return tx.Commit()
-}
-
-func migrateFrom5(db *sql.DB) error {
-	log.Tag(tag).Info("Migrating user database schema: from 5 to 6")
-	tx, err := db.Begin()
-	if err != nil {
-		return err
-	}
-	defer tx.Rollback()
-	if _, err := tx.Exec(migrate5To6UpdateQueries); err != nil {
-		return err
-	}
-	if _, err := tx.Exec(updateSchemaVersion, 6); err != nil {
-		return err
-	}
-	return tx.Commit()
-}
-
 func nullString(s string) sql.NullString {
 	if s == "" {
 		return sql.NullString{}

user/manager_pg.go

@@ -0,0 +1,175 @@
+package user
+
+import (
+	"database/sql"
+	"fmt"
+
+	_ "github.com/jackc/pgx/v5/stdlib" // PostgreSQL driver
+	"heckel.io/ntfy/v2/log"
+)
+
+// PostgreSQL-specific queries
+const (
+	pgCreateTablesQueries = `
+		BEGIN;
+		CREATE TABLE IF NOT EXISTS tier (
+			id TEXT PRIMARY KEY,
+			code TEXT NOT NULL,
+			name TEXT NOT NULL,
+			messages_limit INT NOT NULL,
+			messages_expiry_duration INT NOT NULL,
+			emails_limit INT NOT NULL,
+			calls_limit INT NOT NULL,
+			reservations_limit INT NOT NULL,
+			attachment_file_size_limit INT NOT NULL,
+			attachment_total_size_limit INT NOT NULL,
+			attachment_expiry_duration INT NOT NULL,
+			attachment_bandwidth_limit INT NOT NULL,
+			stripe_monthly_price_id TEXT,
+			stripe_yearly_price_id TEXT
+		);
+		CREATE UNIQUE INDEX IF NOT EXISTS idx_tier_code ON tier (code);
+		CREATE UNIQUE INDEX IF NOT EXISTS idx_tier_stripe_monthly_price_id ON tier (stripe_monthly_price_id);
+		CREATE UNIQUE INDEX IF NOT EXISTS idx_tier_stripe_yearly_price_id ON tier (stripe_yearly_price_id);
+		CREATE TABLE IF NOT EXISTS "user" (
+		    id TEXT PRIMARY KEY,
+			tier_id TEXT,
+			"user" TEXT NOT NULL,
+			pass TEXT NOT NULL,
+			role TEXT CHECK (role IN ('anonymous', 'admin', 'user')) NOT NULL,
+			prefs JSON NOT NULL DEFAULT '{}',
+			sync_topic TEXT NOT NULL,
+			provisioned INT NOT NULL,
+			stats_messages INT NOT NULL DEFAULT 0,
+			stats_emails INT NOT NULL DEFAULT 0,
+			stats_calls INT NOT NULL DEFAULT 0,
+			stripe_customer_id TEXT,
+			stripe_subscription_id TEXT,
+			stripe_subscription_status TEXT,
+			stripe_subscription_interval TEXT,
+			stripe_subscription_paid_until INT,
+			stripe_subscription_cancel_at INT,
+			created INT NOT NULL,
+			deleted INT,
+		    FOREIGN KEY (tier_id) REFERENCES tier (id)
+		);
+		CREATE UNIQUE INDEX IF NOT EXISTS idx_user ON "user" ("user");
+		CREATE UNIQUE INDEX IF NOT EXISTS idx_user_stripe_customer_id ON "user" (stripe_customer_id);
+		CREATE UNIQUE INDEX IF NOT EXISTS idx_user_stripe_subscription_id ON "user" (stripe_subscription_id);
+		CREATE TABLE IF NOT EXISTS user_access (
+			user_id TEXT NOT NULL,
+			topic TEXT NOT NULL,
+			read INT NOT NULL,
+			write INT NOT NULL,
+			owner_user_id TEXT,
+			provisioned INT NOT NULL,
+			PRIMARY KEY (user_id, topic),
+			FOREIGN KEY (user_id) REFERENCES "user" (id) ON DELETE CASCADE,
+		    FOREIGN KEY (owner_user_id) REFERENCES "user" (id) ON DELETE CASCADE
+		);
+		CREATE TABLE IF NOT EXISTS user_token (
+			user_id TEXT NOT NULL,
+			token TEXT NOT NULL,
+			label TEXT NOT NULL,
+			last_access INT NOT NULL,
+			last_origin TEXT NOT NULL,
+			expires INT NOT NULL,
+			provisioned INT NOT NULL,
+			PRIMARY KEY (user_id, token),
+			FOREIGN KEY (user_id) REFERENCES "user" (id) ON DELETE CASCADE
+		);
+		CREATE UNIQUE INDEX IF NOT EXISTS idx_user_token ON user_token (token);
+		CREATE TABLE IF NOT EXISTS user_phone (
+			user_id TEXT NOT NULL,
+			phone_number TEXT NOT NULL,
+			PRIMARY KEY (user_id, phone_number),
+			FOREIGN KEY (user_id) REFERENCES "user" (id) ON DELETE CASCADE
+		);
+		CREATE TABLE IF NOT EXISTS schema_version (
+			id INT PRIMARY KEY,
+			version INT NOT NULL
+		);
+		INSERT INTO "user" (id, "user", pass, role, sync_topic, provisioned, created)
+		VALUES ('` + everyoneID + `', '*', '', 'anonymous', '', 0, EXTRACT(EPOCH FROM NOW())::INT)
+		ON CONFLICT (id) DO NOTHING;
+		COMMIT;
+	`
+
+	pgCurrentSchemaVersion     = 1
+	pgInsertSchemaVersion      = `INSERT INTO schema_version VALUES (1, $1)`
+	pgUpdateSchemaVersion      = `UPDATE schema_version SET version = $1 WHERE id = 1`
+	pgSelectSchemaVersionQuery = `SELECT version FROM schema_version WHERE id = 1`
+)
+
+// newPgManager creates a new PostgreSQL-backed user manager
+func newPgManager(config *Config) (*Manager, error) {
+	db, err := sql.Open("pgx", config.Filename)
+	if err != nil {
+		return nil, err
+	}
+	if err := db.Ping(); err != nil {
+		return nil, fmt.Errorf("failed to connect to PostgreSQL: %w", err)
+	}
+	if err := setupPgDB(db); err != nil {
+		return nil, err
+	}
+	if err := runPgStartupQueries(db, config.StartupQueries); err != nil {
+		return nil, err
+	}
+	return &Manager{
+		config:     config,
+		db:         db,
+		statsQueue: make(map[string]*Stats),
+		tokenQueue: make(map[string]*TokenUpdate),
+	}, nil
+}
+
+func runPgStartupQueries(db *sql.DB, startupQueries string) error {
+	if startupQueries != "" {
+		if _, err := db.Exec(startupQueries); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func setupPgDB(db *sql.DB) error {
+	// If 'schema_version' table does not exist, this must be a new database
+	rowsSV, err := db.Query(pgSelectSchemaVersionQuery)
+	if err != nil {
+		return setupNewPgDB(db)
+	}
+	defer rowsSV.Close()
+
+	// If 'schema_version' table exists, read version and potentially upgrade
+	schemaVersion := 0
+	if !rowsSV.Next() {
+		// Table exists but no rows, insert version
+		return setupNewPgDB(db)
+	}
+	if err := rowsSV.Scan(&schemaVersion); err != nil {
+		return err
+	}
+	rowsSV.Close()
+
+	// Do migrations
+	if schemaVersion == pgCurrentSchemaVersion {
+		return nil
+	} else if schemaVersion > pgCurrentSchemaVersion {
+		return fmt.Errorf("unexpected schema version: version %d is higher than current version %d", schemaVersion, pgCurrentSchemaVersion)
+	}
+
+	// No migrations needed yet for PG (starting at version 1)
+	log.Tag(tag).Info("PostgreSQL user database schema is up to date (version %d)", schemaVersion)
+	return nil
+}
+
+func setupNewPgDB(db *sql.DB) error {
+	if _, err := db.Exec(pgCreateTablesQueries); err != nil {
+		return err
+	}
+	if _, err := db.Exec(pgInsertSchemaVersion, pgCurrentSchemaVersion); err != nil {
+		return err
+	}
+	return nil
+}

user/manager_sqlite.go

@@ -0,0 +1,532 @@
+package user
+
+import (
+	"database/sql"
+	"errors"
+	"fmt"
+	"path/filepath"
+
+	"github.com/mattn/go-sqlite3"
+	"heckel.io/ntfy/v2/log"
+	"heckel.io/ntfy/v2/util"
+)
+
+var (
+	errNoRows = errors.New("no rows found")
+)
+
+// SQLite-specific queries
+const (
+	sqliteCreateTablesQueries = `
+		BEGIN;
+		CREATE TABLE IF NOT EXISTS tier (
+			id TEXT PRIMARY KEY,
+			code TEXT NOT NULL,
+			name TEXT NOT NULL,
+			messages_limit INT NOT NULL,
+			messages_expiry_duration INT NOT NULL,
+			emails_limit INT NOT NULL,
+			calls_limit INT NOT NULL,
+			reservations_limit INT NOT NULL,
+			attachment_file_size_limit INT NOT NULL,
+			attachment_total_size_limit INT NOT NULL,
+			attachment_expiry_duration INT NOT NULL,
+			attachment_bandwidth_limit INT NOT NULL,
+			stripe_monthly_price_id TEXT,
+			stripe_yearly_price_id TEXT
+		);
+		CREATE UNIQUE INDEX idx_tier_code ON tier (code);
+		CREATE UNIQUE INDEX idx_tier_stripe_monthly_price_id ON tier (stripe_monthly_price_id);
+		CREATE UNIQUE INDEX idx_tier_stripe_yearly_price_id ON tier (stripe_yearly_price_id);
+		CREATE TABLE IF NOT EXISTS user (
+		    id TEXT PRIMARY KEY,
+			tier_id TEXT,
+			user TEXT NOT NULL,
+			pass TEXT NOT NULL,
+			role TEXT CHECK (role IN ('anonymous', 'admin', 'user')) NOT NULL,
+			prefs JSON NOT NULL DEFAULT '{}',
+			sync_topic TEXT NOT NULL,
+			provisioned INT NOT NULL,
+			stats_messages INT NOT NULL DEFAULT (0),
+			stats_emails INT NOT NULL DEFAULT (0),
+			stats_calls INT NOT NULL DEFAULT (0),
+			stripe_customer_id TEXT,
+			stripe_subscription_id TEXT,
+			stripe_subscription_status TEXT,
+			stripe_subscription_interval TEXT,
+			stripe_subscription_paid_until INT,
+			stripe_subscription_cancel_at INT,
+			created INT NOT NULL,
+			deleted INT,
+		    FOREIGN KEY (tier_id) REFERENCES tier (id)
+		);
+		CREATE UNIQUE INDEX idx_user ON user (user);
+		CREATE UNIQUE INDEX idx_user_stripe_customer_id ON user (stripe_customer_id);
+		CREATE UNIQUE INDEX idx_user_stripe_subscription_id ON user (stripe_subscription_id);
+		CREATE TABLE IF NOT EXISTS user_access (
+			user_id TEXT NOT NULL,
+			topic TEXT NOT NULL,
+			read INT NOT NULL,
+			write INT NOT NULL,
+			owner_user_id INT,
+			provisioned INT NOT NULL,
+			PRIMARY KEY (user_id, topic),
+			FOREIGN KEY (user_id) REFERENCES user (id) ON DELETE CASCADE,
+		    FOREIGN KEY (owner_user_id) REFERENCES user (id) ON DELETE CASCADE
+		);
+		CREATE TABLE IF NOT EXISTS user_token (
+			user_id TEXT NOT NULL,
+			token TEXT NOT NULL,
+			label TEXT NOT NULL,
+			last_access INT NOT NULL,
+			last_origin TEXT NOT NULL,
+			expires INT NOT NULL,
+			provisioned INT NOT NULL,
+			PRIMARY KEY (user_id, token),
+			FOREIGN KEY (user_id) REFERENCES user (id) ON DELETE CASCADE
+		);
+		CREATE UNIQUE INDEX idx_user_token ON user_token (token);
+		CREATE TABLE IF NOT EXISTS user_phone (
+			user_id TEXT NOT NULL,
+			phone_number TEXT NOT NULL,
+			PRIMARY KEY (user_id, phone_number),
+			FOREIGN KEY (user_id) REFERENCES user (id) ON DELETE CASCADE
+		);
+		CREATE TABLE IF NOT EXISTS schemaVersion (
+			id INT PRIMARY KEY,
+			version INT NOT NULL
+		);
+		INSERT INTO user (id, user, pass, role, sync_topic, provisioned, created)
+		VALUES ('` + everyoneID + `', '*', '', 'anonymous', '', false, UNIXEPOCH())
+		ON CONFLICT (id) DO NOTHING;
+		COMMIT;
+	`
+
+	sqliteBuiltinStartupQueries = `
+		PRAGMA foreign_keys = ON;
+	`
+)
+
+// Schema management queries
+const (
+	sqliteCurrentSchemaVersion     = 6
+	sqliteInsertSchemaVersion      = `INSERT INTO schemaVersion VALUES (1, ?)`
+	sqliteUpdateSchemaVersion      = `UPDATE schemaVersion SET version = ? WHERE id = 1`
+	sqliteSelectSchemaVersionQuery = `SELECT version FROM schemaVersion WHERE id = 1`
+
+	// Migration queries (1->2 through 5->6)
+	// These are SQLite-specific due to PRAGMA, ALTER TABLE syntax, etc.
+	migrate1To2CreateTablesQueries = `
+		ALTER TABLE user RENAME TO user_old;
+		CREATE TABLE IF NOT EXISTS tier (
+			id TEXT PRIMARY KEY,
+			code TEXT NOT NULL,
+			name TEXT NOT NULL,
+			messages_limit INT NOT NULL,
+			messages_expiry_duration INT NOT NULL,
+			emails_limit INT NOT NULL,
+			reservations_limit INT NOT NULL,
+			attachment_file_size_limit INT NOT NULL,
+			attachment_total_size_limit INT NOT NULL,
+			attachment_expiry_duration INT NOT NULL,
+			attachment_bandwidth_limit INT NOT NULL,
+			stripe_price_id TEXT
+		);
+		CREATE UNIQUE INDEX idx_tier_code ON tier (code);
+		CREATE UNIQUE INDEX idx_tier_price_id ON tier (stripe_price_id);
+		CREATE TABLE IF NOT EXISTS user (
+		    id TEXT PRIMARY KEY,
+			tier_id TEXT,
+			user TEXT NOT NULL,
+			pass TEXT NOT NULL,
+			role TEXT CHECK (role IN ('anonymous', 'admin', 'user')) NOT NULL,
+			prefs JSON NOT NULL DEFAULT '{}',
+			sync_topic TEXT NOT NULL,
+			stats_messages INT NOT NULL DEFAULT (0),
+			stats_emails INT NOT NULL DEFAULT (0),
+			stripe_customer_id TEXT,
+			stripe_subscription_id TEXT,
+			stripe_subscription_status TEXT,
+			stripe_subscription_paid_until INT,
+			stripe_subscription_cancel_at INT,
+			created INT NOT NULL,
+			deleted INT,
+		    FOREIGN KEY (tier_id) REFERENCES tier (id)
+		);
+		CREATE UNIQUE INDEX idx_user ON user (user);
+		CREATE UNIQUE INDEX idx_user_stripe_customer_id ON user (stripe_customer_id);
+		CREATE UNIQUE INDEX idx_user_stripe_subscription_id ON user (stripe_subscription_id);
+		CREATE TABLE IF NOT EXISTS user_access (
+			user_id TEXT NOT NULL,
+			topic TEXT NOT NULL,
+			read INT NOT NULL,
+			write INT NOT NULL,
+			owner_user_id INT,
+			PRIMARY KEY (user_id, topic),
+			FOREIGN KEY (user_id) REFERENCES user (id) ON DELETE CASCADE,
+		    FOREIGN KEY (owner_user_id) REFERENCES user (id) ON DELETE CASCADE
+		);
+		CREATE TABLE IF NOT EXISTS user_token (
+			user_id TEXT NOT NULL,
+			token TEXT NOT NULL,
+			label TEXT NOT NULL,
+			last_access INT NOT NULL,
+			last_origin TEXT NOT NULL,
+			expires INT NOT NULL,
+			PRIMARY KEY (user_id, token),
+			FOREIGN KEY (user_id) REFERENCES user (id) ON DELETE CASCADE
+		);
+		CREATE TABLE IF NOT EXISTS schemaVersion (
+			id INT PRIMARY KEY,
+			version INT NOT NULL
+		);
+		INSERT INTO user (id, user, pass, role, sync_topic, created)
+		VALUES ('u_everyone', '*', '', 'anonymous', '', UNIXEPOCH())
+		ON CONFLICT (id) DO NOTHING;
+	`
+	migrate1To2SelectAllOldUsernamesNoTx = `SELECT user FROM user_old`
+	migrate1To2InsertUserNoTx            = `
+		INSERT INTO user (id, user, pass, role, sync_topic, created)
+		SELECT ?, user, pass, role, ?, UNIXEPOCH() FROM user_old WHERE user = ?
+	`
+	migrate1To2InsertFromOldTablesAndDropNoTx = `
+		INSERT INTO user_access (user_id, topic, read, write)
+		SELECT u.id, a.topic, a.read, a.write
+		FROM user u
+	 	JOIN access a ON u.user = a.user;
+
+		DROP TABLE access;
+		DROP TABLE user_old;
+	`
+
+	migrate2To3UpdateQueries = `
+		ALTER TABLE user ADD COLUMN stripe_subscription_interval TEXT;
+		ALTER TABLE tier RENAME COLUMN stripe_price_id TO stripe_monthly_price_id;
+		ALTER TABLE tier ADD COLUMN stripe_yearly_price_id TEXT;
+		DROP INDEX IF EXISTS idx_tier_price_id;
+		CREATE UNIQUE INDEX idx_tier_stripe_monthly_price_id ON tier (stripe_monthly_price_id);
+		CREATE UNIQUE INDEX idx_tier_stripe_yearly_price_id ON tier (stripe_yearly_price_id);
+	`
+
+	migrate3To4UpdateQueries = `
+		ALTER TABLE tier ADD COLUMN calls_limit INT NOT NULL DEFAULT (0);
+		ALTER TABLE user ADD COLUMN stats_calls INT NOT NULL DEFAULT (0);
+		CREATE TABLE IF NOT EXISTS user_phone (
+			user_id TEXT NOT NULL,
+			phone_number TEXT NOT NULL,
+			PRIMARY KEY (user_id, phone_number),
+			FOREIGN KEY (user_id) REFERENCES user (id) ON DELETE CASCADE
+		);
+	`
+
+	migrate4To5UpdateQueries = `
+		UPDATE user_access SET topic = REPLACE(topic, '_', '\_');
+	`
+
+	migrate5To6UpdateQueries = `
+		PRAGMA foreign_keys=off;
+
+		-- Alter user table: Add provisioned column
+		ALTER TABLE user RENAME TO user_old;
+		CREATE TABLE IF NOT EXISTS user (
+		    id TEXT PRIMARY KEY,
+			tier_id TEXT,
+			user TEXT NOT NULL,
+			pass TEXT NOT NULL,
+			role TEXT CHECK (role IN ('anonymous', 'admin', 'user')) NOT NULL,
+			prefs JSON NOT NULL DEFAULT '{}',
+			sync_topic TEXT NOT NULL,
+			provisioned INT NOT NULL,
+			stats_messages INT NOT NULL DEFAULT (0),
+			stats_emails INT NOT NULL DEFAULT (0),
+			stats_calls INT NOT NULL DEFAULT (0),
+			stripe_customer_id TEXT,
+			stripe_subscription_id TEXT,
+			stripe_subscription_status TEXT,
+			stripe_subscription_interval TEXT,
+			stripe_subscription_paid_until INT,
+			stripe_subscription_cancel_at INT,
+			created INT NOT NULL,
+			deleted INT,
+		    FOREIGN KEY (tier_id) REFERENCES tier (id)
+		);
+		INSERT INTO user
+		SELECT
+		    id,
+		    tier_id,
+		    user,
+		    pass,
+		    role,
+		    prefs,
+		    sync_topic,
+		    0, -- provisioned
+		    stats_messages,
+		    stats_emails,
+		    stats_calls,
+		    stripe_customer_id,
+		    stripe_subscription_id,
+		    stripe_subscription_status,
+		    stripe_subscription_interval,
+		    stripe_subscription_paid_until,
+		    stripe_subscription_cancel_at,
+		    created,
+		    deleted
+		FROM user_old;
+		DROP TABLE user_old;
+
+		-- Alter user_access table: Add provisioned column
+		ALTER TABLE user_access RENAME TO user_access_old;
+		CREATE TABLE user_access (
+			user_id TEXT NOT NULL,
+			topic TEXT NOT NULL,
+			read INT NOT NULL,
+			write INT NOT NULL,
+			owner_user_id INT,
+			provisioned INTEGER NOT NULL,
+			PRIMARY KEY (user_id, topic),
+			FOREIGN KEY (user_id) REFERENCES user (id) ON DELETE CASCADE,
+			FOREIGN KEY (owner_user_id) REFERENCES user (id) ON DELETE CASCADE
+		);
+		INSERT INTO user_access SELECT *, 0 FROM user_access_old;
+		DROP TABLE user_access_old;
+
+		-- Alter user_token table: Add provisioned column
+		ALTER TABLE user_token RENAME TO user_token_old;
+		CREATE TABLE IF NOT EXISTS user_token (
+			user_id TEXT NOT NULL,
+			token TEXT NOT NULL,
+			label TEXT NOT NULL,
+			last_access INT NOT NULL,
+			last_origin TEXT NOT NULL,
+			expires INT NOT NULL,
+			provisioned INT NOT NULL,
+			PRIMARY KEY (user_id, token),
+			FOREIGN KEY (user_id) REFERENCES user (id) ON DELETE CASCADE
+		);
+		INSERT INTO user_token SELECT *, 0 FROM user_token_old;
+		DROP TABLE user_token_old;
+
+		-- Recreate indices
+		CREATE UNIQUE INDEX idx_user ON user (user);
+		CREATE UNIQUE INDEX idx_user_stripe_customer_id ON user (stripe_customer_id);
+		CREATE UNIQUE INDEX idx_user_stripe_subscription_id ON user (stripe_subscription_id);
+		CREATE UNIQUE INDEX idx_user_token ON user_token (token);
+
+		-- Re-enable foreign keys
+		PRAGMA foreign_keys=on;
+	`
+)
+
+var (
+	sqliteMigrations = map[int]func(db *sql.DB) error{
+		1: migrateFrom1,
+		2: migrateFrom2,
+		3: migrateFrom3,
+		4: migrateFrom4,
+		5: migrateFrom5,
+	}
+)
+
+// newSqliteManager creates a new SQLite-backed Manager
+func newSqliteManager(config *Config) (*Manager, error) {
+	// Check the parent directory of the database file (makes for friendly error messages)
+	parentDir := filepath.Dir(config.Filename)
+	if !util.FileExists(parentDir) {
+		return nil, fmt.Errorf("user database directory %s does not exist or is not accessible", parentDir)
+	}
+	// Open DB and run setup queries
+	db, err := sql.Open("sqlite3", config.Filename)
+	if err != nil {
+		return nil, err
+	}
+	if err := setupSqliteDB(db); err != nil {
+		return nil, err
+	}
+	if err := runSqliteStartupQueries(db, config.StartupQueries); err != nil {
+		return nil, err
+	}
+	return &Manager{
+		db:         db,
+		config:     config,
+		statsQueue: make(map[string]*Stats),
+		tokenQueue: make(map[string]*TokenUpdate),
+	}, nil
+}
+
+func runSqliteStartupQueries(db *sql.DB, startupQueries string) error {
+	if startupQueries != "" {
+		if _, err := db.Exec(startupQueries); err != nil {
+			return err
+		}
+	}
+	if _, err := db.Exec(sqliteBuiltinStartupQueries); err != nil {
+		return err
+	}
+	return nil
+}
+
+func setupSqliteDB(db *sql.DB) error {
+	// If 'schemaVersion' table does not exist, this must be a new database
+	rowsSV, err := db.Query(sqliteSelectSchemaVersionQuery)
+	if err != nil {
+		return setupNewSqliteDB(db)
+	}
+	defer rowsSV.Close()
+
+	// If 'schemaVersion' table exists, read version and potentially upgrade
+	schemaVersion := 0
+	if !rowsSV.Next() {
+		return errors.New("cannot determine schema version: database file may be corrupt")
+	}
+	if err := rowsSV.Scan(&schemaVersion); err != nil {
+		return err
+	}
+	rowsSV.Close()
+
+	// Do migrations
+	if schemaVersion == sqliteCurrentSchemaVersion {
+		return nil
+	} else if schemaVersion > sqliteCurrentSchemaVersion {
+		return fmt.Errorf("unexpected schema version: version %d is higher than current version %d", schemaVersion, sqliteCurrentSchemaVersion)
+	}
+	for i := schemaVersion; i < sqliteCurrentSchemaVersion; i++ {
+		fn, ok := sqliteMigrations[i]
+		if !ok {
+			return fmt.Errorf("cannot find migration step from schema version %d to %d", i, i+1)
+		} else if err := fn(db); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func setupNewSqliteDB(db *sql.DB) error {
+	if _, err := db.Exec(sqliteCreateTablesQueries); err != nil {
+		return err
+	}
+	if _, err := db.Exec(sqliteInsertSchemaVersion, sqliteCurrentSchemaVersion); err != nil {
+		return err
+	}
+	return nil
+}
+
+func migrateFrom1(db *sql.DB) error {
+	log.Tag(tag).Info("Migrating user database schema: from 1 to 2")
+	tx, err := db.Begin()
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+	// Rename user -> user_old, and create new tables
+	if _, err := tx.Exec(migrate1To2CreateTablesQueries); err != nil {
+		return err
+	}
+	// Insert users from user_old into new user table, with ID and sync_topic
+	rows, err := tx.Query(migrate1To2SelectAllOldUsernamesNoTx)
+	if err != nil {
+		return err
+	}
+	defer rows.Close()
+	usernames := make([]string, 0)
+	for rows.Next() {
+		var username string
+		if err := rows.Scan(&username); err != nil {
+			return err
+		}
+		usernames = append(usernames, username)
+	}
+	if err := rows.Close(); err != nil {
+		return err
+	}
+	for _, username := range usernames {
+		userID := util.RandomStringPrefix(userIDPrefix, userIDLength)
+		syncTopic := util.RandomStringPrefix(syncTopicPrefix, syncTopicLength)
+		if _, err := tx.Exec(migrate1To2InsertUserNoTx, userID, syncTopic, username); err != nil {
+			return err
+		}
+	}
+	// Migrate old "access" table to "user_access" and drop "access" and "user_old"
+	if _, err := tx.Exec(migrate1To2InsertFromOldTablesAndDropNoTx); err != nil {
+		return err
+	}
+	if _, err := tx.Exec(sqliteUpdateSchemaVersion, 2); err != nil {
+		return err
+	}
+	if err := tx.Commit(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func migrateFrom2(db *sql.DB) error {
+	log.Tag(tag).Info("Migrating user database schema: from 2 to 3")
+	tx, err := db.Begin()
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+	if _, err := tx.Exec(migrate2To3UpdateQueries); err != nil {
+		return err
+	}
+	if _, err := tx.Exec(sqliteUpdateSchemaVersion, 3); err != nil {
+		return err
+	}
+	return tx.Commit()
+}
+
+func migrateFrom3(db *sql.DB) error {
+	log.Tag(tag).Info("Migrating user database schema: from 3 to 4")
+	tx, err := db.Begin()
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+	if _, err := tx.Exec(migrate3To4UpdateQueries); err != nil {
+		return err
+	}
+	if _, err := tx.Exec(sqliteUpdateSchemaVersion, 4); err != nil {
+		return err
+	}
+	return tx.Commit()
+}
+
+func migrateFrom4(db *sql.DB) error {
+	log.Tag(tag).Info("Migrating user database schema: from 4 to 5")
+	tx, err := db.Begin()
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+	if _, err := tx.Exec(migrate4To5UpdateQueries); err != nil {
+		return err
+	}
+	if _, err := tx.Exec(sqliteUpdateSchemaVersion, 5); err != nil {
+		return err
+	}
+	return tx.Commit()
+}
+
+func migrateFrom5(db *sql.DB) error {
+	log.Tag(tag).Info("Migrating user database schema: from 5 to 6")
+	tx, err := db.Begin()
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+	if _, err := tx.Exec(migrate5To6UpdateQueries); err != nil {
+		return err
+	}
+	if _, err := tx.Exec(sqliteUpdateSchemaVersion, 6); err != nil {
+		return err
+	}
+	return tx.Commit()
+}
+
+// isSqliteConstraintUniqueError checks if the error is a SQLite unique constraint error
+func isSqliteConstraintUniqueError(err error) bool {
+	if sqliteErr, ok := err.(sqlite3.Error); ok && sqliteErr.ExtendedCode == sqlite3.ErrConstraintUnique {
+		return true
+	}
+	return errors.Is(err, sqlite3.ErrConstraintUnique)
+}
+

user/manager_test.go

@@ -1578,7 +1578,7 @@ func checkSchemaVersion(t *testing.T, db *sql.DB) {
 
 	var schemaVersion int
 	require.Nil(t, rows.Scan(&schemaVersion))
-	require.Equal(t, currentSchemaVersion, schemaVersion)
+	require.Equal(t, sqliteCurrentSchemaVersion, schemaVersion)
 	require.Nil(t, rows.Close())
 }