diff --git a/compact.go b/compact.go
new file mode 100644
index 0000000..9af6b8c
--- /dev/null
+++ b/compact.go
@@ -0,0 +1,191 @@
+package store
+
+import (
+	"compress/gzip"
+	"io"
+	"time"
+
+	core "dappco.re/go/core"
+)
+
+var defaultArchiveOutputDirectory = ".core/archive"
+
+// CompactOptions controls cold archive generation.
+// Usage example: `options := store.CompactOptions{Before: time.Now().Add(-90 * 24 * time.Hour), Output: "/tmp/archive", Format: "gzip"}`
+type CompactOptions struct {
+	Before time.Time
+	Output string
+	Format string
+}
+
+type compactArchiveEntry struct {
+	id          int64
+	bucket      string
+	measurement string
+	fieldsJSON  string
+	tagsJSON    string
+	committedAt int64
+}
+
+// Compact archives old journal entries as newline-delimited JSON.
+// Usage example: `result := storeInstance.Compact(store.CompactOptions{Before: time.Now().Add(-30 * 24 * time.Hour), Output: "/tmp/archive", Format: "gzip"})`
+func (storeInstance *Store) Compact(options CompactOptions) core.Result {
+	if err := ensureJournalSchema(storeInstance.database); err != nil {
+		return core.Result{Value: core.E("store.Compact", "ensure journal schema", err), OK: false}
+	}
+
+	outputDirectory := options.Output
+	if outputDirectory == "" {
+		outputDirectory = defaultArchiveOutputDirectory
+	}
+	format := options.Format
+	if format == "" {
+		format = "gzip"
+	}
+	if format != "gzip" {
+		return core.Result{Value: core.E("store.Compact", core.Concat("unsupported archive format: ", format), nil), OK: false}
+	}
+
+	filesystem := (&core.Fs{}).NewUnrestricted()
+	if result := filesystem.EnsureDir(outputDirectory); !result.OK {
+		return core.Result{Value: core.E("store.Compact", "ensure archive directory", result.Value.(error)), OK: false}
+	}
+
+	rows, err := storeInstance.database.Query(
+		"SELECT entry_id, bucket_name, measurement, fields_json, tags_json, committed_at FROM "+journalEntriesTableName+" WHERE archived_at IS NULL AND committed_at < ? ORDER BY committed_at",
+		options.Before.UnixMilli(),
+	)
+	if err != nil {
+		return core.Result{Value: core.E("store.Compact", "query journal rows", err), OK: false}
+	}
+	defer rows.Close()
+
+	var archiveEntries []compactArchiveEntry
+	for rows.Next() {
+		var entry compactArchiveEntry
+		if err := rows.Scan(
+			&entry.id,
+			&entry.bucket,
+			&entry.measurement,
+			&entry.fieldsJSON,
+			&entry.tagsJSON,
+			&entry.committedAt,
+		); err != nil {
+			return core.Result{Value: core.E("store.Compact", "scan journal row", err), OK: false}
+		}
+		archiveEntries = append(archiveEntries, entry)
+	}
+	if err := rows.Err(); err != nil {
+		return core.Result{Value: core.E("store.Compact", "iterate journal rows", err), OK: false}
+	}
+	if len(archiveEntries) == 0 {
+		return core.Result{Value: "", OK: true}
+	}
+
+	outputPath := compactOutputPath(outputDirectory, format)
+	createResult := filesystem.Create(outputPath)
+	if !createResult.OK {
+		return core.Result{Value: core.E("store.Compact", "create archive file", createResult.Value.(error)), OK: false}
+	}
+
+	file, ok := createResult.Value.(io.WriteCloser)
+	if !ok {
+		return core.Result{Value: core.E("store.Compact", "archive file is not writable", nil), OK: false}
+	}
+	fileClosed := false
+	defer func() {
+		if !fileClosed {
+			_ = file.Close()
+		}
+	}()
+
+	writer := gzip.NewWriter(file)
+	writeOK := false
+	defer func() {
+		if !writeOK {
+			_ = writer.Close()
+		}
+	}()
+
+	for _, entry := range archiveEntries {
+		lineMap, err := compactArchiveLine(entry)
+		if err != nil {
+			return core.Result{Value: err, OK: false}
+		}
+		lineJSON, err := jsonString(lineMap, "store.Compact", "marshal archive line")
+		if err != nil {
+			return core.Result{Value: err, OK: false}
+		}
+		if _, err := io.WriteString(writer, lineJSON+"\n"); err != nil {
+			return core.Result{Value: core.E("store.Compact", "write archive line", err), OK: false}
+		}
+	}
+	if err := writer.Close(); err != nil {
+		return core.Result{Value: core.E("store.Compact", "close archive writer", err), OK: false}
+	}
+	writeOK = true
+	if err := file.Close(); err != nil {
+		return core.Result{Value: core.E("store.Compact", "close archive file", err), OK: false}
+	}
+	fileClosed = true
+
+	transaction, err := storeInstance.database.Begin()
+	if err != nil {
+		return core.Result{Value: core.E("store.Compact", "begin archive transaction", err), OK: false}
+	}
+
+	committed := false
+	defer func() {
+		if !committed {
+			_ = transaction.Rollback()
+		}
+	}()
+
+	archivedAt := time.Now().UnixMilli()
+	for _, entry := range archiveEntries {
+		if _, err := transaction.Exec(
+			"UPDATE "+journalEntriesTableName+" SET archived_at = ? WHERE entry_id = ?",
+			archivedAt,
+			entry.id,
+		); err != nil {
+			return core.Result{Value: core.E("store.Compact", "mark journal row archived", err), OK: false}
+		}
+	}
+	if err := transaction.Commit(); err != nil {
+		return core.Result{Value: core.E("store.Compact", "commit archive transaction", err), OK: false}
+	}
+	committed = true
+
+	return core.Result{Value: outputPath, OK: true}
+}
+
+func compactArchiveLine(entry compactArchiveEntry) (map[string]any, error) {
+	fields := make(map[string]any)
+	fieldsResult := core.JSONUnmarshalString(entry.fieldsJSON, &fields)
+	if !fieldsResult.OK {
+		return nil, core.E("store.Compact", "unmarshal fields", fieldsResult.Value.(error))
+	}
+
+	tags := make(map[string]string)
+	tagsResult := core.JSONUnmarshalString(entry.tagsJSON, &tags)
+	if !tagsResult.OK {
+		return nil, core.E("store.Compact", "unmarshal tags", tagsResult.Value.(error))
+	}
+
+	return map[string]any{
+		"bucket":       entry.bucket,
+		"measurement":  entry.measurement,
+		"fields":       fields,
+		"tags":         tags,
+		"committed_at": entry.committedAt,
+	}, nil
+}
+
+func compactOutputPath(outputDirectory, format string) string {
+	extension := ".jsonl"
+	if format == "gzip" {
+		extension = ".jsonl.gz"
+	}
+	filename := core.Concat("journal-", time.Now().UTC().Format("20060102-150405"), extension)
+	return joinPath(outputDirectory, filename)
+}
diff --git a/compact_test.go b/compact_test.go
new file mode 100644
index 0000000..0cb1889
--- /dev/null
+++ b/compact_test.go
@@ -0,0 +1,81 @@
+package store
+
+import (
+	"bytes"
+	"compress/gzip"
+	"io"
+	"testing"
+	"time"
+
+	core "dappco.re/go/core"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCompact_Compact_Good_GzipArchive(t *testing.T) {
+	outputDirectory := useArchiveOutputDirectory(t)
+
+	storeInstance, err := New(":memory:", WithJournal("http://127.0.0.1:8086", "core", "events"))
+	require.NoError(t, err)
+	defer storeInstance.Close()
+
+	require.True(t,
+		storeInstance.CommitToJournal("session-a", map[string]any{"like": 1}, map[string]string{"workspace": "session-a"}).OK,
+	)
+	require.True(t,
+		storeInstance.CommitToJournal("session-b", map[string]any{"like": 2}, map[string]string{"workspace": "session-b"}).OK,
+	)
+
+	_, err = storeInstance.database.Exec(
+		"UPDATE "+journalEntriesTableName+" SET committed_at = ? WHERE measurement = ?",
+		time.Now().Add(-48*time.Hour).UnixMilli(),
+		"session-a",
+	)
+	require.NoError(t, err)
+
+	result := storeInstance.Compact(CompactOptions{
+		Before: time.Now().Add(-24 * time.Hour),
+		Output: outputDirectory,
+		Format: "gzip",
+	})
+	require.True(t, result.OK, "compact failed: %v", result.Value)
+
+	archivePath, ok := result.Value.(string)
+	require.True(t, ok, "unexpected archive path type: %T", result.Value)
+	assert.True(t, testFilesystem().Exists(archivePath))
+
+	archiveData := requireCoreReadBytes(t, archivePath)
+	reader, err := gzip.NewReader(bytes.NewReader(archiveData))
+	require.NoError(t, err)
+	defer reader.Close()
+
+	decompressedData, err := io.ReadAll(reader)
+	require.NoError(t, err)
+	lines := core.Split(core.Trim(string(decompressedData)), "\n")
+	require.Len(t, lines, 1)
+
+	archivedRow := make(map[string]any)
+	unmarshalResult := core.JSONUnmarshalString(lines[0], &archivedRow)
+	require.True(t, unmarshalResult.OK, "archive line unmarshal failed: %v", unmarshalResult.Value)
+	assert.Equal(t, "session-a", archivedRow["measurement"])
+
+	remainingRows := requireResultRows(t, storeInstance.QueryJournal(""))
+	require.Len(t, remainingRows, 1)
+	assert.Equal(t, "session-b", remainingRows[0]["measurement"])
+}
+
+func TestCompact_Compact_Good_NoRows(t *testing.T) {
+	outputDirectory := useArchiveOutputDirectory(t)
+
+	storeInstance, err := New(":memory:")
+	require.NoError(t, err)
+	defer storeInstance.Close()
+
+	result := storeInstance.Compact(CompactOptions{
+		Before: time.Now(),
+		Output: outputDirectory,
+		Format: "gzip",
+	})
+	require.True(t, result.OK, "compact failed: %v", result.Value)
+	assert.Equal(t, "", result.Value)
+}
diff --git a/events.go b/events.go
index bbe89ab..a3ce353 100644
--- a/events.go
+++ b/events.go
@@ -77,13 +77,18 @@ const watcherEventBufferCapacity = 16
 
 // Watch registers a buffered subscription for matching mutations.
 // Usage example: `watcher := storeInstance.Watch("*", "*")`
-func (storeInstance *Store) Watch(group, key string) *Watcher {
+// Usage example: `watcher := storeInstance.Watch("config")`
+func (storeInstance *Store) Watch(group string, key ...string) *Watcher {
+	keyPattern := "*"
+	if len(key) > 0 && key[0] != "" {
+		keyPattern = key[0]
+	}
 	eventChannel := make(chan Event, watcherEventBufferCapacity)
 	watcher := &Watcher{
 		Events:         eventChannel,
 		eventsChannel:  eventChannel,
 		groupPattern:   group,
-		keyPattern:     key,
+		keyPattern:     keyPattern,
 		registrationID: atomic.AddUint64(&storeInstance.nextWatcherRegistrationID, 1),
 	}
 
@@ -115,7 +120,9 @@ func (storeInstance *Store) Unwatch(watcher *Watcher) {
 
 // OnChange registers a synchronous mutation callback.
 // Usage example: `events := make(chan store.Event, 1); unregister := storeInstance.OnChange(func(event store.Event) { events <- event }); defer unregister()`
-func (storeInstance *Store) OnChange(callback func(Event)) func() {
+// Usage example: `unregister := storeInstance.OnChange("config", func(key, value string) { fmt.Println(key, value) })`
+func (storeInstance *Store) OnChange(arguments ...any) func() {
+	callback := onChangeCallback(arguments)
 	if callback == nil {
 		return func() {}
 	}
@@ -140,6 +147,39 @@ func (storeInstance *Store) OnChange(callback func(Event)) func() {
 	}
 }
 
+func onChangeCallback(arguments []any) func(Event) {
+	switch len(arguments) {
+	case 0:
+		return nil
+	case 1:
+		if arguments[0] == nil {
+			return nil
+		}
+		callback, ok := arguments[0].(func(Event))
+		if !ok {
+			return nil
+		}
+		return callback
+	case 2:
+		group, ok := arguments[0].(string)
+		if !ok {
+			return nil
+		}
+		callback, ok := arguments[1].(func(string, string))
+		if !ok || callback == nil {
+			return nil
+		}
+		return func(event Event) {
+			if event.Group != group {
+				return
+			}
+			callback(event.Key, event.Value)
+		}
+	default:
+		return nil
+	}
+}
+
 // notify(Event{Type: EventSet, Group: "config", Key: "colour", Value: "blue"})
 // dispatches matching watchers and callbacks after a successful write. If a
 // watcher buffer is full, the event is dropped instead of blocking the writer.
diff --git a/events_test.go b/events_test.go
index 2e04080..924d7a4 100644
--- a/events_test.go
+++ b/events_test.go
@@ -66,6 +66,22 @@ func TestEvents_Watch_Good_WildcardKey(t *testing.T) {
 	assert.Equal(t, "colour", received[1].Key)
 }
 
+func TestEvents_Watch_Good_DefaultWildcardKey(t *testing.T) {
+	storeInstance, _ := New(":memory:")
+	defer storeInstance.Close()
+
+	watcher := storeInstance.Watch("config")
+	defer storeInstance.Unwatch(watcher)
+
+	require.NoError(t, storeInstance.Set("config", "theme", "dark"))
+	require.NoError(t, storeInstance.Set("config", "colour", "blue"))
+
+	received := drainEvents(watcher.Events, 2, time.Second)
+	require.Len(t, received, 2)
+	assert.Equal(t, "theme", received[0].Key)
+	assert.Equal(t, "colour", received[1].Key)
+}
+
 func TestEvents_Watch_Good_GroupMismatch(t *testing.T) {
 	storeInstance, _ := New(":memory:")
 	defer storeInstance.Close()
@@ -300,6 +316,22 @@ func TestEvents_OnChange_Good_NilCallbackNoOp(t *testing.T) {
 	unregister()
 }
 
+func TestEvents_OnChange_Good_GroupCallback(t *testing.T) {
+	storeInstance, _ := New(":memory:")
+	defer storeInstance.Close()
+
+	var keys []string
+	unregister := storeInstance.OnChange("config", func(key, value string) {
+		keys = append(keys, key)
+	})
+	defer unregister()
+
+	require.NoError(t, storeInstance.Set("config", "theme", "dark"))
+	require.NoError(t, storeInstance.Set("other", "theme", "ignored"))
+
+	assert.Equal(t, []string{"theme"}, keys)
+}
+
 // ---------------------------------------------------------------------------
 // OnChange — callback can manage subscriptions while handling an event
 // ---------------------------------------------------------------------------
diff --git a/journal.go b/journal.go
new file mode 100644
index 0000000..04b255d
--- /dev/null
+++ b/journal.go
@@ -0,0 +1,291 @@
+package store
+
+import (
+	"database/sql"
+	"regexp"
+	"strconv"
+	"time"
+
+	core "dappco.re/go/core"
+)
+
+const (
+	journalEntriesTableName = "journal_entries"
+	defaultJournalBucket    = "store"
+)
+
+const createJournalEntriesTableSQL = `CREATE TABLE IF NOT EXISTS journal_entries (
+	entry_id      INTEGER PRIMARY KEY AUTOINCREMENT,
+	bucket_name   TEXT NOT NULL,
+	measurement   TEXT NOT NULL,
+	fields_json   TEXT NOT NULL,
+	tags_json     TEXT NOT NULL,
+	committed_at  INTEGER NOT NULL,
+	archived_at   INTEGER
+)`
+
+var (
+	journalBucketPattern      = regexp.MustCompile(`bucket:\s*"([^"]+)"`)
+	journalRangePattern       = regexp.MustCompile(`range\(\s*start:\s*([^)]+)\)`)
+	journalMeasurementPattern = regexp.MustCompile(`(?:_measurement|measurement)\s*==\s*"([^"]+)"`)
+)
+
+type journalExecutor interface {
+	Exec(query string, args ...any) (sql.Result, error)
+}
+
+// CommitToJournal records one completed unit of work in the store journal.
+// Usage example: `result := storeInstance.CommitToJournal("scroll-session", map[string]any{"like": 4}, map[string]string{"workspace": "scroll-session"})`
+func (storeInstance *Store) CommitToJournal(measurement string, fields map[string]any, tags map[string]string) core.Result {
+	if measurement == "" {
+		return core.Result{Value: core.E("store.CommitToJournal", "measurement is empty", nil), OK: false}
+	}
+	if fields == nil {
+		fields = map[string]any{}
+	}
+	if tags == nil {
+		tags = map[string]string{}
+	}
+	if err := ensureJournalSchema(storeInstance.database); err != nil {
+		return core.Result{Value: core.E("store.CommitToJournal", "ensure journal schema", err), OK: false}
+	}
+
+	fieldsJSON, err := jsonString(fields, "store.CommitToJournal", "marshal fields")
+	if err != nil {
+		return core.Result{Value: err, OK: false}
+	}
+	tagsJSON, err := jsonString(tags, "store.CommitToJournal", "marshal tags")
+	if err != nil {
+		return core.Result{Value: err, OK: false}
+	}
+
+	committedAt := time.Now().UnixMilli()
+	if err := insertJournalEntry(
+		storeInstance.database,
+		storeInstance.journalBucket(),
+		measurement,
+		fieldsJSON,
+		tagsJSON,
+		committedAt,
+	); err != nil {
+		return core.Result{Value: core.E("store.CommitToJournal", "insert journal entry", err), OK: false}
+	}
+
+	return core.Result{
+		Value: map[string]any{
+			"bucket":       storeInstance.journalBucket(),
+			"measurement":  measurement,
+			"fields":       fields,
+			"tags":         tags,
+			"committed_at": committedAt,
+		},
+		OK: true,
+	}
+}
+
+// QueryJournal reads journal rows either through a small Flux-like filter
+// surface or a direct SQL SELECT against the internal journal table.
+// Usage example: `result := storeInstance.QueryJournal(\`from(bucket: "store") |> range(start: -24h)\`)`
+func (storeInstance *Store) QueryJournal(flux string) core.Result {
+	if err := ensureJournalSchema(storeInstance.database); err != nil {
+		return core.Result{Value: core.E("store.QueryJournal", "ensure journal schema", err), OK: false}
+	}
+
+	trimmedQuery := core.Trim(flux)
+	if trimmedQuery == "" {
+		return storeInstance.queryJournalRows(
+			"SELECT bucket_name, measurement, fields_json, tags_json, committed_at, archived_at FROM " + journalEntriesTableName + " WHERE archived_at IS NULL ORDER BY committed_at",
+		)
+	}
+	if core.HasPrefix(trimmedQuery, "SELECT") || core.HasPrefix(trimmedQuery, "select") {
+		return storeInstance.queryJournalRows(trimmedQuery)
+	}
+
+	selectSQL, arguments, err := storeInstance.queryJournalFlux(trimmedQuery)
+	if err != nil {
+		return core.Result{Value: err, OK: false}
+	}
+	return storeInstance.queryJournalRows(selectSQL, arguments...)
+}
+
+func (storeInstance *Store) queryJournalRows(query string, arguments ...any) core.Result {
+	rows, err := storeInstance.database.Query(query, arguments...)
+	if err != nil {
+		return core.Result{Value: core.E("store.QueryJournal", "query rows", err), OK: false}
+	}
+	defer rows.Close()
+
+	rowMaps, err := queryRowsAsMaps(rows)
+	if err != nil {
+		return core.Result{Value: core.E("store.QueryJournal", "scan rows", err), OK: false}
+	}
+	return core.Result{Value: inflateJournalRows(rowMaps), OK: true}
+}
+
+func (storeInstance *Store) queryJournalFlux(flux string) (string, []any, error) {
+	builder := core.NewBuilder()
+	builder.WriteString("SELECT bucket_name, measurement, fields_json, tags_json, committed_at, archived_at FROM ")
+	builder.WriteString(journalEntriesTableName)
+	builder.WriteString(" WHERE archived_at IS NULL")
+
+	var arguments []any
+	if bucket := quotedSubmatch(journalBucketPattern, flux); bucket != "" {
+		builder.WriteString(" AND bucket_name = ?")
+		arguments = append(arguments, bucket)
+	}
+	if measurement := quotedSubmatch(journalMeasurementPattern, flux); measurement != "" {
+		builder.WriteString(" AND measurement = ?")
+		arguments = append(arguments, measurement)
+	}
+
+	rangeMatch := quotedSubmatch(journalRangePattern, flux)
+	if rangeMatch == "" {
+		rangeMatch = regexpSubmatch(journalRangePattern, flux, 1)
+	}
+	if rangeMatch != "" {
+		startTime, err := fluxStartTime(core.Trim(rangeMatch))
+		if err != nil {
+			return "", nil, core.E("store.QueryJournal", "parse range", err)
+		}
+		builder.WriteString(" AND committed_at >= ?")
+		arguments = append(arguments, startTime.UnixMilli())
+	}
+
+	builder.WriteString(" ORDER BY committed_at")
+	return builder.String(), arguments, nil
+}
+
+func (storeInstance *Store) journalBucket() string {
+	if storeInstance.journal.bucket == "" {
+		return defaultJournalBucket
+	}
+	return storeInstance.journal.bucket
+}
+
+func ensureJournalSchema(database schemaDatabase) error {
+	if _, err := database.Exec(createJournalEntriesTableSQL); err != nil {
+		return err
+	}
+	if _, err := database.Exec(
+		"CREATE INDEX IF NOT EXISTS journal_entries_bucket_committed_at_idx ON " + journalEntriesTableName + " (bucket_name, committed_at)",
+	); err != nil {
+		return err
+	}
+	return nil
+}
+
+func insertJournalEntry(
+	executor journalExecutor,
+	bucket, measurement, fieldsJSON, tagsJSON string,
+	committedAt int64,
+) error {
+	_, err := executor.Exec(
+		"INSERT INTO "+journalEntriesTableName+" (bucket_name, measurement, fields_json, tags_json, committed_at, archived_at) VALUES (?, ?, ?, ?, ?, NULL)",
+		bucket,
+		measurement,
+		fieldsJSON,
+		tagsJSON,
+		committedAt,
+	)
+	return err
+}
+
+func jsonString(value any, operation, message string) (string, error) {
+	result := core.JSONMarshal(value)
+	if !result.OK {
+		return "", core.E(operation, message, result.Value.(error))
+	}
+	return string(result.Value.([]byte)), nil
+}
+
+func fluxStartTime(value string) (time.Time, error) {
+	if value == "" {
+		return time.Time{}, core.E("store.fluxStartTime", "range value is empty", nil)
+	}
+	if core.HasSuffix(value, "d") {
+		days, err := strconv.Atoi(core.TrimSuffix(value, "d"))
+		if err != nil {
+			return time.Time{}, err
+		}
+		return time.Now().Add(time.Duration(days) * 24 * time.Hour), nil
+	}
+	lookback, err := time.ParseDuration(value)
+	if err != nil {
+		return time.Time{}, err
+	}
+	return time.Now().Add(lookback), nil
+}
+
+func quotedSubmatch(pattern *regexp.Regexp, value string) string {
+	match := pattern.FindStringSubmatch(value)
+	if len(match) < 2 {
+		return ""
+	}
+	return match[1]
+}
+
+func regexpSubmatch(pattern *regexp.Regexp, value string, index int) string {
+	match := pattern.FindStringSubmatch(value)
+	if len(match) <= index {
+		return ""
+	}
+	return match[index]
+}
+
+func queryRowsAsMaps(rows *sql.Rows) ([]map[string]any, error) {
+	columnNames, err := rows.Columns()
+	if err != nil {
+		return nil, err
+	}
+
+	var result []map[string]any
+	for rows.Next() {
+		rawValues := make([]any, len(columnNames))
+		scanTargets := make([]any, len(columnNames))
+		for i := range rawValues {
+			scanTargets[i] = &rawValues[i]
+		}
+		if err := rows.Scan(scanTargets...); err != nil {
+			return nil, err
+		}
+
+		row := make(map[string]any, len(columnNames))
+		for i, columnName := range columnNames {
+			row[columnName] = normaliseRowValue(rawValues[i])
+		}
+		result = append(result, row)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return result, nil
+}
+
+func inflateJournalRows(rows []map[string]any) []map[string]any {
+	for _, row := range rows {
+		if fieldsJSON, ok := row["fields_json"].(string); ok {
+			fields := make(map[string]any)
+			result := core.JSONUnmarshalString(fieldsJSON, &fields)
+			if result.OK {
+				row["fields"] = fields
+			}
+		}
+		if tagsJSON, ok := row["tags_json"].(string); ok {
+			tags := make(map[string]string)
+			result := core.JSONUnmarshalString(tagsJSON, &tags)
+			if result.OK {
+				row["tags"] = tags
+			}
+		}
+	}
+	return rows
+}
+
+func normaliseRowValue(value any) any {
+	switch typedValue := value.(type) {
+	case []byte:
+		return string(typedValue)
+	default:
+		return typedValue
+	}
+}
diff --git a/journal_test.go b/journal_test.go
new file mode 100644
index 0000000..9801079
--- /dev/null
+++ b/journal_test.go
@@ -0,0 +1,69 @@
+package store
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestJournal_CommitToJournal_Good_WithQueryJournalSQL(t *testing.T) {
+	storeInstance, err := New(":memory:", WithJournal("http://127.0.0.1:8086", "core", "events"))
+	require.NoError(t, err)
+	defer storeInstance.Close()
+
+	first := storeInstance.CommitToJournal("session-a", map[string]any{"like": 4}, map[string]string{"workspace": "session-a"})
+	second := storeInstance.CommitToJournal("session-b", map[string]any{"profile_match": 2}, map[string]string{"workspace": "session-b"})
+	require.True(t, first.OK, "first journal commit failed: %v", first.Value)
+	require.True(t, second.OK, "second journal commit failed: %v", second.Value)
+
+	rows := requireResultRows(
+		t,
+		storeInstance.QueryJournal("SELECT bucket_name, measurement, fields_json, tags_json FROM journal_entries ORDER BY entry_id"),
+	)
+	require.Len(t, rows, 2)
+	assert.Equal(t, "events", rows[0]["bucket_name"])
+	assert.Equal(t, "session-a", rows[0]["measurement"])
+
+	fields, ok := rows[0]["fields"].(map[string]any)
+	require.True(t, ok, "unexpected fields type: %T", rows[0]["fields"])
+	assert.Equal(t, float64(4), fields["like"])
+
+	tags, ok := rows[1]["tags"].(map[string]string)
+	require.True(t, ok, "unexpected tags type: %T", rows[1]["tags"])
+	assert.Equal(t, "session-b", tags["workspace"])
+}
+
+func TestJournal_QueryJournal_Good_FluxFilters(t *testing.T) {
+	storeInstance, err := New(":memory:", WithJournal("http://127.0.0.1:8086", "core", "events"))
+	require.NoError(t, err)
+	defer storeInstance.Close()
+
+	require.True(t,
+		storeInstance.CommitToJournal("session-a", map[string]any{"like": 1}, map[string]string{"workspace": "session-a"}).OK,
+	)
+	require.True(t,
+		storeInstance.CommitToJournal("session-b", map[string]any{"like": 2}, map[string]string{"workspace": "session-b"}).OK,
+	)
+
+	rows := requireResultRows(
+		t,
+		storeInstance.QueryJournal(`from(bucket: "events") |> range(start: -24h) |> filter(fn: (r) => r._measurement == "session-b")`),
+	)
+	require.Len(t, rows, 1)
+	assert.Equal(t, "session-b", rows[0]["measurement"])
+
+	fields, ok := rows[0]["fields"].(map[string]any)
+	require.True(t, ok, "unexpected fields type: %T", rows[0]["fields"])
+	assert.Equal(t, float64(2), fields["like"])
+}
+
+func TestJournal_CommitToJournal_Bad_EmptyMeasurement(t *testing.T) {
+	storeInstance, err := New(":memory:")
+	require.NoError(t, err)
+	defer storeInstance.Close()
+
+	result := storeInstance.CommitToJournal("", map[string]any{"like": 1}, map[string]string{"workspace": "missing"})
+	require.False(t, result.OK)
+	assert.Contains(t, result.Value.(error).Error(), "measurement is empty")
+}
diff --git a/scope.go b/scope.go
index ef8c05f..c2a275f 100644
--- a/scope.go
+++ b/scope.go
@@ -11,6 +11,8 @@ import (
 // validNamespace.MatchString("tenant-a") is true; validNamespace.MatchString("tenant_a") is false.
 var validNamespace = regexp.MustCompile(`^[a-zA-Z0-9-]+$`)
 
+const defaultScopedGroupName = "default"
+
 // QuotaConfig sets per-namespace key and group limits.
 // Usage example: `quota := store.QuotaConfig{MaxKeys: 100, MaxGroups: 10}`
 type QuotaConfig struct {
@@ -25,7 +27,8 @@ type QuotaConfig struct {
 type ScopedStore struct {
 	storeInstance *Store
 	namespace     string
-	quota         QuotaConfig
+	MaxKeys       int
+	MaxGroups     int
 }
 
 // NewScoped validates a namespace and prefixes groups with namespace + ":".
@@ -55,7 +58,8 @@ func NewScopedWithQuota(storeInstance *Store, namespace string, quota QuotaConfi
 			nil,
 		)
 	}
-	scopedStore.quota = quota
+	scopedStore.MaxKeys = quota.MaxKeys
+	scopedStore.MaxGroups = quota.MaxGroups
 	return scopedStore, nil
 }
 
@@ -67,6 +71,10 @@ func (scopedStore *ScopedStore) namespacePrefix() string {
 	return scopedStore.namespace + ":"
 }
 
+func (scopedStore *ScopedStore) defaultGroup() string {
+	return defaultScopedGroupName
+}
+
 func (scopedStore *ScopedStore) trimNamespacePrefix(groupName string) string {
 	return core.TrimPrefix(groupName, scopedStore.namespacePrefix())
 }
@@ -77,19 +85,41 @@ func (scopedStore *ScopedStore) Namespace() string {
 	return scopedStore.namespace
 }
 
+// Usage example: `colourValue, err := scopedStore.Get("colour")`
 // Usage example: `colourValue, err := scopedStore.Get("config", "colour")`
-func (scopedStore *ScopedStore) Get(group, key string) (string, error) {
+func (scopedStore *ScopedStore) Get(arguments ...string) (string, error) {
+	group, key, err := scopedStore.getArguments(arguments)
+	if err != nil {
+		return "", err
+	}
 	return scopedStore.storeInstance.Get(scopedStore.namespacedGroup(group), key)
 }
 
+// GetFrom reads a key from an explicit namespaced group.
+// Usage example: `colourValue, err := scopedStore.GetFrom("config", "colour")`
+func (scopedStore *ScopedStore) GetFrom(group, key string) (string, error) {
+	return scopedStore.Get(group, key)
+}
+
+// Usage example: `if err := scopedStore.Set("colour", "blue"); err != nil { return }`
 // Usage example: `if err := scopedStore.Set("config", "colour", "blue"); err != nil { return }`
-func (scopedStore *ScopedStore) Set(group, key, value string) error {
+func (scopedStore *ScopedStore) Set(arguments ...string) error {
+	group, key, value, err := scopedStore.setArguments(arguments)
+	if err != nil {
+		return err
+	}
 	if err := scopedStore.checkQuota("store.ScopedStore.Set", group, key); err != nil {
 		return err
 	}
 	return scopedStore.storeInstance.Set(scopedStore.namespacedGroup(group), key, value)
 }
 
+// SetIn writes a key to an explicit namespaced group.
+// Usage example: `if err := scopedStore.SetIn("config", "colour", "blue"); err != nil { return }`
+func (scopedStore *ScopedStore) SetIn(group, key, value string) error {
+	return scopedStore.Set(group, key, value)
+}
+
 // Usage example: `if err := scopedStore.SetWithTTL("sessions", "token", "abc123", time.Hour); err != nil { return }`
 func (scopedStore *ScopedStore) SetWithTTL(group, key, value string, timeToLive time.Duration) error {
 	if err := scopedStore.checkQuota("store.ScopedStore.SetWithTTL", group, key); err != nil {
@@ -118,19 +148,26 @@ func (scopedStore *ScopedStore) All(group string) iter.Seq2[KeyValue, error] {
 	return scopedStore.storeInstance.All(scopedStore.namespacedGroup(group))
 }
 
+// Usage example: `for entry, err := range scopedStore.AllSeq("config") { if err != nil { break }; fmt.Println(entry.Key, entry.Value) }`
+func (scopedStore *ScopedStore) AllSeq(group string) iter.Seq2[KeyValue, error] {
+	return scopedStore.All(group)
+}
+
 // Usage example: `keyCount, err := scopedStore.Count("config")`
 func (scopedStore *ScopedStore) Count(group string) (int, error) {
 	return scopedStore.storeInstance.Count(scopedStore.namespacedGroup(group))
 }
 
 // Usage example: `keyCount, err := scopedStore.CountAll("config")`
-func (scopedStore *ScopedStore) CountAll(groupPrefix string) (int, error) {
-	return scopedStore.storeInstance.CountAll(scopedStore.namespacedGroup(groupPrefix))
+// Usage example: `keyCount, err := scopedStore.CountAll()`
+func (scopedStore *ScopedStore) CountAll(groupPrefix ...string) (int, error) {
+	return scopedStore.storeInstance.CountAll(scopedStore.namespacedGroup(firstString(groupPrefix)))
 }
 
 // Usage example: `groupNames, err := scopedStore.Groups("config")`
-func (scopedStore *ScopedStore) Groups(groupPrefix string) ([]string, error) {
-	groupNames, err := scopedStore.storeInstance.Groups(scopedStore.namespacedGroup(groupPrefix))
+// Usage example: `groupNames, err := scopedStore.Groups()`
+func (scopedStore *ScopedStore) Groups(groupPrefix ...string) ([]string, error) {
+	groupNames, err := scopedStore.storeInstance.Groups(scopedStore.namespacedGroup(firstString(groupPrefix)))
 	if err != nil {
 		return nil, err
 	}
@@ -141,10 +178,11 @@ func (scopedStore *ScopedStore) Groups(groupPrefix string) ([]string, error) {
 }
 
 // Usage example: `for groupName, err := range scopedStore.GroupsSeq("config") { if err != nil { break }; fmt.Println(groupName) }`
-func (scopedStore *ScopedStore) GroupsSeq(groupPrefix string) iter.Seq2[string, error] {
+// Usage example: `for groupName, err := range scopedStore.GroupsSeq() { if err != nil { break }; fmt.Println(groupName) }`
+func (scopedStore *ScopedStore) GroupsSeq(groupPrefix ...string) iter.Seq2[string, error] {
 	return func(yield func(string, error) bool) {
 		namespacePrefix := scopedStore.namespacePrefix()
-		for groupName, err := range scopedStore.storeInstance.GroupsSeq(scopedStore.namespacedGroup(groupPrefix)) {
+		for groupName, err := range scopedStore.storeInstance.GroupsSeq(scopedStore.namespacedGroup(firstString(groupPrefix))) {
 			if err != nil {
 				if !yield("", err) {
 					return
@@ -187,7 +225,7 @@ func (scopedStore *ScopedStore) PurgeExpired() (int64, error) {
 // group would exceed the configured limit. Existing keys are treated as
 // upserts and do not consume quota.
 func (scopedStore *ScopedStore) checkQuota(operation, group, key string) error {
-	if scopedStore.quota.MaxKeys == 0 && scopedStore.quota.MaxGroups == 0 {
+	if scopedStore.MaxKeys == 0 && scopedStore.MaxGroups == 0 {
 		return nil
 	}
 
@@ -206,18 +244,18 @@ func (scopedStore *ScopedStore) checkQuota(operation, group, key string) error {
 	}
 
 	// Check MaxKeys quota.
-	if scopedStore.quota.MaxKeys > 0 {
+	if scopedStore.MaxKeys > 0 {
 		keyCount, err := scopedStore.storeInstance.CountAll(namespacePrefix)
 		if err != nil {
 			return core.E(operation, "quota check", err)
 		}
-		if keyCount >= scopedStore.quota.MaxKeys {
-			return core.E(operation, core.Sprintf("key limit (%d)", scopedStore.quota.MaxKeys), QuotaExceededError)
+		if keyCount >= scopedStore.MaxKeys {
+			return core.E(operation, core.Sprintf("key limit (%d)", scopedStore.MaxKeys), QuotaExceededError)
 		}
 	}
 
 	// Check MaxGroups quota — only if this would create a new group.
-	if scopedStore.quota.MaxGroups > 0 {
+	if scopedStore.MaxGroups > 0 {
 		existingGroupCount, err := scopedStore.storeInstance.Count(namespacedGroup)
 		if err != nil {
 			return core.E(operation, "quota check", err)
@@ -231,11 +269,41 @@ func (scopedStore *ScopedStore) checkQuota(operation, group, key string) error {
 				}
 				knownGroupCount++
 			}
-			if knownGroupCount >= scopedStore.quota.MaxGroups {
-				return core.E(operation, core.Sprintf("group limit (%d)", scopedStore.quota.MaxGroups), QuotaExceededError)
+			if knownGroupCount >= scopedStore.MaxGroups {
+				return core.E(operation, core.Sprintf("group limit (%d)", scopedStore.MaxGroups), QuotaExceededError)
 			}
 		}
 	}
 
 	return nil
 }
+
+func (scopedStore *ScopedStore) getArguments(arguments []string) (string, string, error) {
+	switch len(arguments) {
+	case 1:
+		return scopedStore.defaultGroup(), arguments[0], nil
+	case 2:
+		return arguments[0], arguments[1], nil
+	default:
+		return "", "", core.E(
+			"store.ScopedStore.Get",
+			core.Sprintf("expected 1 or 2 arguments; got %d", len(arguments)),
+			nil,
+		)
+	}
+}
+
+func (scopedStore *ScopedStore) setArguments(arguments []string) (string, string, string, error) {
+	switch len(arguments) {
+	case 2:
+		return scopedStore.defaultGroup(), arguments[0], arguments[1], nil
+	case 3:
+		return arguments[0], arguments[1], arguments[2], nil
+	default:
+		return "", "", "", core.E(
+			"store.ScopedStore.Set",
+			core.Sprintf("expected 2 or 3 arguments; got %d", len(arguments)),
+			nil,
+		)
+	}
+}
diff --git a/scope_test.go b/scope_test.go
index ee76260..e7fda9b 100644
--- a/scope_test.go
+++ b/scope_test.go
@@ -94,6 +94,17 @@ func TestScope_NewScopedWithQuota_Bad_NegativeMaxGroups(t *testing.T) {
 	assert.Contains(t, err.Error(), "zero or positive")
 }
 
+func TestScope_NewScopedWithQuota_Good_InlineQuotaFields(t *testing.T) {
+	storeInstance, _ := New(":memory:")
+	defer storeInstance.Close()
+
+	scopedStore, err := NewScopedWithQuota(storeInstance, "tenant-a", QuotaConfig{MaxKeys: 4, MaxGroups: 2})
+	require.NoError(t, err)
+
+	assert.Equal(t, 4, scopedStore.MaxKeys)
+	assert.Equal(t, 2, scopedStore.MaxGroups)
+}
+
 // ---------------------------------------------------------------------------
 // ScopedStore — basic CRUD
 // ---------------------------------------------------------------------------
@@ -110,6 +121,34 @@ func TestScope_ScopedStore_Good_SetGet(t *testing.T) {
 	assert.Equal(t, "dark", value)
 }
 
+func TestScope_ScopedStore_Good_DefaultGroupHelpers(t *testing.T) {
+	storeInstance, _ := New(":memory:")
+	defer storeInstance.Close()
+
+	scopedStore, _ := NewScoped(storeInstance, "tenant-a")
+	require.NoError(t, scopedStore.Set("theme", "dark"))
+
+	value, err := scopedStore.Get("theme")
+	require.NoError(t, err)
+	assert.Equal(t, "dark", value)
+
+	rawValue, err := storeInstance.Get("tenant-a:default", "theme")
+	require.NoError(t, err)
+	assert.Equal(t, "dark", rawValue)
+}
+
+func TestScope_ScopedStore_Good_SetInGetFrom(t *testing.T) {
+	storeInstance, _ := New(":memory:")
+	defer storeInstance.Close()
+
+	scopedStore, _ := NewScoped(storeInstance, "tenant-a")
+	require.NoError(t, scopedStore.SetIn("config", "theme", "dark"))
+
+	value, err := scopedStore.GetFrom("config", "theme")
+	require.NoError(t, err)
+	assert.Equal(t, "dark", value)
+}
+
 func TestScope_ScopedStore_Good_PrefixedInUnderlyingStore(t *testing.T) {
 	storeInstance, _ := New(":memory:")
 	defer storeInstance.Close()
diff --git a/store.go b/store.go
index 49db3c4..7eb3ab5 100644
--- a/store.go
+++ b/store.go
@@ -29,14 +29,25 @@ const (
 	entryValueColumn        = "entry_value"
 )
 
+// StoreOption customises Store construction.
+// Usage example: `storeInstance, err := store.New("/tmp/go-store.db", store.WithJournal("http://127.0.0.1:8086", "core", "events"))`
+type StoreOption func(*Store)
+
+type journalConfig struct {
+	url    string
+	org    string
+	bucket string
+}
+
 // Store provides SQLite-backed grouped entries with TTL expiry, namespace
-// isolation, and reactive change notifications.
+// isolation, reactive change notifications, and optional journal support.
 // Usage example: `storeInstance, err := store.New(":memory:"); if err != nil { return }; if err := storeInstance.Set("config", "colour", "blue"); err != nil { return }`
 type Store struct {
 	database       *sql.DB
 	cancelPurge    context.CancelFunc
 	purgeWaitGroup sync.WaitGroup
 	purgeInterval  time.Duration // interval between background purge cycles
+	journal        journalConfig
 
 	// Event dispatch state.
 	watchers                   []*Watcher
@@ -47,8 +58,18 @@ type Store struct {
 	nextCallbackRegistrationID uint64       // monotonic ID for callback registrations
 }
 
-// Usage example: `storeInstance, err := store.New(":memory:"); if err != nil { return }`
-func New(databasePath string) (*Store, error) {
+// WithJournal records journal connection metadata for workspace commits,
+// journal queries, and archive generation.
+// Usage example: `storeInstance, err := store.New("/tmp/go-store.db", store.WithJournal("http://127.0.0.1:8086", "core", "events"))`
+func WithJournal(url, org, bucket string) StoreOption {
+	return func(storeInstance *Store) {
+		storeInstance.journal = journalConfig{url: url, org: org, bucket: bucket}
+	}
+}
+
+// Usage example: `storeInstance, err := store.New(":memory:")`
+// Usage example: `storeInstance, err := store.New("/tmp/go-store.db", store.WithJournal("http://127.0.0.1:8086", "core", "events"))`
+func New(databasePath string, options ...StoreOption) (*Store, error) {
 	sqliteDatabase, err := sql.Open("sqlite", databasePath)
 	if err != nil {
 		return nil, core.E("store.New", "open database", err)
@@ -73,6 +94,11 @@ func New(databasePath string) (*Store, error) {
 
 	purgeContext, cancel := context.WithCancel(context.Background())
 	storeInstance := &Store{database: sqliteDatabase, cancelPurge: cancel, purgeInterval: 60 * time.Second}
+	for _, option := range options {
+		if option != nil {
+			option(storeInstance)
+		}
+	}
 	storeInstance.startBackgroundPurge(purgeContext)
 	return storeInstance, nil
 }
@@ -236,6 +262,11 @@ func (storeInstance *Store) All(group string) iter.Seq2[KeyValue, error] {
 	}
 }
 
+// Usage example: `for entry, err := range storeInstance.AllSeq("config") { if err != nil { break }; fmt.Println(entry.Key, entry.Value) }`
+func (storeInstance *Store) AllSeq(group string) iter.Seq2[KeyValue, error] {
+	return storeInstance.All(group)
+}
+
 // Usage example: `parts, err := storeInstance.GetSplit("config", "hosts", ","); if err != nil { return }; for part := range parts { fmt.Println(part) }`
 func (storeInstance *Store) GetSplit(group, key, separator string) (iter.Seq[string], error) {
 	value, err := storeInstance.Get(group, key)
@@ -297,9 +328,10 @@ func (storeInstance *Store) CountAll(groupPrefix string) (int, error) {
 }
 
 // Usage example: `tenantGroupNames, err := storeInstance.Groups("tenant-a:")`
-func (storeInstance *Store) Groups(groupPrefix string) ([]string, error) {
+// Usage example: `allGroupNames, err := storeInstance.Groups()`
+func (storeInstance *Store) Groups(groupPrefix ...string) ([]string, error) {
 	var groupNames []string
-	for groupName, err := range storeInstance.GroupsSeq(groupPrefix) {
+	for groupName, err := range storeInstance.GroupsSeq(groupPrefix...) {
 		if err != nil {
 			return nil, err
 		}
@@ -309,12 +341,14 @@ func (storeInstance *Store) Groups(groupPrefix string) ([]string, error) {
 }
 
 // Usage example: `for tenantGroupName, err := range storeInstance.GroupsSeq("tenant-a:") { if err != nil { break }; fmt.Println(tenantGroupName) }`
-func (storeInstance *Store) GroupsSeq(groupPrefix string) iter.Seq2[string, error] {
+// Usage example: `for groupName, err := range storeInstance.GroupsSeq() { if err != nil { break }; fmt.Println(groupName) }`
+func (storeInstance *Store) GroupsSeq(groupPrefix ...string) iter.Seq2[string, error] {
+	actualGroupPrefix := firstString(groupPrefix)
 	return func(yield func(string, error) bool) {
 		var rows *sql.Rows
 		var err error
 		now := time.Now().UnixMilli()
-		if groupPrefix == "" {
+		if actualGroupPrefix == "" {
 			rows, err = storeInstance.database.Query(
 				"SELECT DISTINCT "+entryGroupColumn+" FROM "+entriesTableName+" WHERE (expires_at IS NULL OR expires_at > ?) ORDER BY "+entryGroupColumn,
 				now,
@@ -322,7 +356,7 @@ func (storeInstance *Store) GroupsSeq(groupPrefix string) iter.Seq2[string, erro
 		} else {
 			rows, err = storeInstance.database.Query(
 				"SELECT DISTINCT "+entryGroupColumn+" FROM "+entriesTableName+" WHERE "+entryGroupColumn+" LIKE ? ESCAPE '^' AND (expires_at IS NULL OR expires_at > ?) ORDER BY "+entryGroupColumn,
-				escapeLike(groupPrefix)+"%", now,
+				escapeLike(actualGroupPrefix)+"%", now,
 			)
 		}
 		if err != nil {
@@ -349,6 +383,13 @@ func (storeInstance *Store) GroupsSeq(groupPrefix string) iter.Seq2[string, erro
 	}
 }
 
+func firstString(values []string) string {
+	if len(values) == 0 {
+		return ""
+	}
+	return values[0]
+}
+
 // escapeLike("tenant_%") returns "tenant^_^%" so LIKE queries treat wildcards
 // literally.
 func escapeLike(text string) string {
diff --git a/store_test.go b/store_test.go
index 0089aac..6dc2e44 100644
--- a/store_test.go
+++ b/store_test.go
@@ -98,6 +98,16 @@ func TestStore_New_Good_WALMode(t *testing.T) {
 	assert.Equal(t, "wal", mode, "journal_mode should be WAL")
 }
 
+func TestStore_New_Good_WithJournalOption(t *testing.T) {
+	storeInstance, err := New(":memory:", WithJournal("http://127.0.0.1:8086", "core", "events"))
+	require.NoError(t, err)
+	defer storeInstance.Close()
+
+	assert.Equal(t, "events", storeInstance.journal.bucket)
+	assert.Equal(t, "core", storeInstance.journal.org)
+	assert.Equal(t, "http://127.0.0.1:8086", storeInstance.journal.url)
+}
+
 // ---------------------------------------------------------------------------
 // Set / Get — core CRUD
 // ---------------------------------------------------------------------------
@@ -372,6 +382,22 @@ func TestStore_All_Good_SortedByKey(t *testing.T) {
 	assert.Equal(t, []string{"alpha", "bravo", "charlie"}, keys)
 }
 
+func TestStore_AllSeq_Good_Alias(t *testing.T) {
+	storeInstance, _ := New(":memory:")
+	defer storeInstance.Close()
+
+	require.NoError(t, storeInstance.Set("g", "alpha", "1"))
+	require.NoError(t, storeInstance.Set("g", "bravo", "2"))
+
+	var keys []string
+	for entry, err := range storeInstance.AllSeq("g") {
+		require.NoError(t, err)
+		keys = append(keys, entry.Key)
+	}
+
+	assert.Equal(t, []string{"alpha", "bravo"}, keys)
+}
+
 func TestStore_All_Bad_ClosedStore(t *testing.T) {
 	storeInstance, _ := New(":memory:")
 	storeInstance.Close()
@@ -434,6 +460,22 @@ func TestStore_GroupsSeq_Good_SortedByGroupName(t *testing.T) {
 	assert.Equal(t, []string{"alpha", "bravo", "charlie"}, groups)
 }
 
+func TestStore_GroupsSeq_Good_DefaultArgument(t *testing.T) {
+	storeInstance, _ := New(":memory:")
+	defer storeInstance.Close()
+
+	require.NoError(t, storeInstance.Set("alpha", "a", "1"))
+	require.NoError(t, storeInstance.Set("beta", "b", "2"))
+
+	var groups []string
+	for group, err := range storeInstance.GroupsSeq() {
+		require.NoError(t, err)
+		groups = append(groups, group)
+	}
+
+	assert.Equal(t, []string{"alpha", "beta"}, groups)
+}
+
 func TestStore_GroupsSeq_Bad_ClosedStore(t *testing.T) {
 	storeInstance, _ := New(":memory:")
 	storeInstance.Close()
diff --git a/test_helpers_test.go b/test_helpers_test.go
index a7a5c12..8d4a052 100644
--- a/test_helpers_test.go
+++ b/test_helpers_test.go
@@ -43,3 +43,38 @@ func repeatString(value string, count int) string {
 	}
 	return builder.String()
 }
+
+func useWorkspaceStateDirectory(tb testing.TB) string {
+	tb.Helper()
+
+	previous := defaultWorkspaceStateDirectory
+	stateDirectory := testPath(tb, "state")
+	defaultWorkspaceStateDirectory = stateDirectory
+	tb.Cleanup(func() {
+		defaultWorkspaceStateDirectory = previous
+		_ = testFilesystem().DeleteAll(stateDirectory)
+	})
+	return stateDirectory
+}
+
+func useArchiveOutputDirectory(tb testing.TB) string {
+	tb.Helper()
+
+	previous := defaultArchiveOutputDirectory
+	outputDirectory := testPath(tb, "archive")
+	defaultArchiveOutputDirectory = outputDirectory
+	tb.Cleanup(func() {
+		defaultArchiveOutputDirectory = previous
+		_ = testFilesystem().DeleteAll(outputDirectory)
+	})
+	return outputDirectory
+}
+
+func requireResultRows(tb testing.TB, result core.Result) []map[string]any {
+	tb.Helper()
+
+	require.True(tb, result.OK, "core result failed: %v", result.Value)
+	rows, ok := result.Value.([]map[string]any)
+	require.True(tb, ok, "unexpected row type: %T", result.Value)
+	return rows
+}
diff --git a/workspace.go b/workspace.go
new file mode 100644
index 0000000..2f8753d
--- /dev/null
+++ b/workspace.go
@@ -0,0 +1,326 @@
+package store
+
+import (
+	"database/sql"
+	"io/fs"
+	"sync"
+	"time"
+
+	core "dappco.re/go/core"
+)
+
+const (
+	workspaceEntriesTableName  = "workspace_entries"
+	workspaceIdentityGroupName = "workspace"
+)
+
+const createWorkspaceEntriesTableSQL = `CREATE TABLE IF NOT EXISTS workspace_entries (
+	entry_id    INTEGER PRIMARY KEY AUTOINCREMENT,
+	entry_kind  TEXT NOT NULL,
+	entry_data  TEXT NOT NULL,
+	created_at  INTEGER NOT NULL
+)`
+
+var defaultWorkspaceStateDirectory = ".core/state"
+
+// Workspace accumulates mutable work-in-progress entries before they are
+// committed to the durable store journal.
+// Usage example: `workspace, err := storeInstance.NewWorkspace("scroll-session-2026-03-30"); if err != nil { return }; defer workspace.Discard()`
+type Workspace struct {
+	name          string
+	storeInstance *Store
+	database      *sql.DB
+	databasePath  string
+	filesystem    *core.Fs
+
+	closeLock sync.Mutex
+	closed    bool
+}
+
+// NewWorkspace creates a workspace state file under `.core/state/`.
+// Usage example: `workspace, err := storeInstance.NewWorkspace("scroll-session-2026-03-30")`
+func (storeInstance *Store) NewWorkspace(name string) (*Workspace, error) {
+	validation := core.ValidateName(name)
+	if !validation.OK {
+		return nil, core.E("store.NewWorkspace", "validate workspace name", validation.Value.(error))
+	}
+
+	filesystem := (&core.Fs{}).NewUnrestricted()
+	databasePath := workspaceFilePath(defaultWorkspaceStateDirectory, name)
+	if filesystem.Exists(databasePath) {
+		return nil, core.E("store.NewWorkspace", core.Concat("workspace already exists: ", name), nil)
+	}
+	if result := filesystem.EnsureDir(defaultWorkspaceStateDirectory); !result.OK {
+		return nil, core.E("store.NewWorkspace", "ensure state directory", result.Value.(error))
+	}
+
+	workspaceDatabase, err := openWorkspaceDatabase(databasePath)
+	if err != nil {
+		return nil, core.E("store.NewWorkspace", "open workspace database", err)
+	}
+
+	return &Workspace{
+		name:          name,
+		storeInstance: storeInstance,
+		database:      workspaceDatabase,
+		databasePath:  databasePath,
+		filesystem:    filesystem,
+	}, nil
+}
+
+// RecoverOrphans opens any leftover workspace files so callers can inspect and
+// decide whether to commit or discard them.
+// Usage example: `orphans := storeInstance.RecoverOrphans(".core/state")`
+func (storeInstance *Store) RecoverOrphans(stateDirectory string) []*Workspace {
+	if stateDirectory == "" {
+		stateDirectory = defaultWorkspaceStateDirectory
+	}
+
+	filesystem := (&core.Fs{}).NewUnrestricted()
+	if !filesystem.Exists(stateDirectory) {
+		return nil
+	}
+
+	listResult := filesystem.List(stateDirectory)
+	if !listResult.OK {
+		return nil
+	}
+
+	entries, ok := listResult.Value.([]fs.DirEntry)
+	if !ok {
+		return nil
+	}
+
+	var workspaces []*Workspace
+	for _, dirEntry := range entries {
+		if dirEntry.IsDir() || !core.HasSuffix(dirEntry.Name(), ".duckdb") {
+			continue
+		}
+		name := core.TrimSuffix(dirEntry.Name(), ".duckdb")
+		databasePath := workspaceFilePath(stateDirectory, name)
+		workspaceDatabase, err := openWorkspaceDatabase(databasePath)
+		if err != nil {
+			continue
+		}
+		workspaces = append(workspaces, &Workspace{
+			name:          name,
+			storeInstance: storeInstance,
+			database:      workspaceDatabase,
+			databasePath:  databasePath,
+			filesystem:    filesystem,
+		})
+	}
+	return workspaces
+}
+
+// Put appends one entry to the workspace buffer.
+// Usage example: `err := workspace.Put("like", map[string]any{"user": "@alice", "post": "video_123"})`
+func (workspace *Workspace) Put(kind string, data map[string]any) error {
+	if kind == "" {
+		return core.E("store.Workspace.Put", "kind is empty", nil)
+	}
+	if data == nil {
+		data = map[string]any{}
+	}
+
+	dataJSON, err := jsonString(data, "store.Workspace.Put", "marshal entry data")
+	if err != nil {
+		return err
+	}
+
+	_, err = workspace.database.Exec(
+		"INSERT INTO "+workspaceEntriesTableName+" (entry_kind, entry_data, created_at) VALUES (?, ?, ?)",
+		kind,
+		dataJSON,
+		time.Now().UnixMilli(),
+	)
+	if err != nil {
+		return core.E("store.Workspace.Put", "insert entry", err)
+	}
+	return nil
+}
+
+// Aggregate returns the current per-kind entry counts in the workspace.
+// Usage example: `summary := workspace.Aggregate()`
+func (workspace *Workspace) Aggregate() map[string]any {
+	fields, err := workspace.aggregateFields()
+	if err != nil {
+		return map[string]any{}
+	}
+	return fields
+}
+
+// Commit writes the aggregated workspace state to the journal and updates the
+// store summary entry for the workspace.
+// Usage example: `result := workspace.Commit()`
+func (workspace *Workspace) Commit() core.Result {
+	fields, err := workspace.aggregateFields()
+	if err != nil {
+		return core.Result{Value: core.E("store.Workspace.Commit", "aggregate workspace", err), OK: false}
+	}
+	if err := workspace.storeInstance.commitWorkspaceAggregate(workspace.name, fields); err != nil {
+		return core.Result{Value: err, OK: false}
+	}
+	if err := workspace.closeAndDelete(); err != nil {
+		return core.Result{Value: err, OK: false}
+	}
+	return core.Result{Value: fields, OK: true}
+}
+
+// Discard closes the workspace and removes its backing file.
+// Usage example: `workspace.Discard()`
+func (workspace *Workspace) Discard() {
+	_ = workspace.closeAndDelete()
+}
+
+// Query runs ad-hoc SQL against the workspace buffer.
+// Usage example: `result := workspace.Query("SELECT entry_kind, COUNT(*) AS count FROM workspace_entries GROUP BY entry_kind")`
+func (workspace *Workspace) Query(sqlQuery string) core.Result {
+	rows, err := workspace.database.Query(sqlQuery)
+	if err != nil {
+		return core.Result{Value: core.E("store.Workspace.Query", "query workspace", err), OK: false}
+	}
+	defer rows.Close()
+
+	rowMaps, err := queryRowsAsMaps(rows)
+	if err != nil {
+		return core.Result{Value: core.E("store.Workspace.Query", "scan rows", err), OK: false}
+	}
+	return core.Result{Value: rowMaps, OK: true}
+}
+
+func (workspace *Workspace) aggregateFields() (map[string]any, error) {
+	rows, err := workspace.database.Query(
+		"SELECT entry_kind, COUNT(*) FROM " + workspaceEntriesTableName + " GROUP BY entry_kind ORDER BY entry_kind",
+	)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	fields := make(map[string]any)
+	for rows.Next() {
+		var (
+			kind  string
+			count int
+		)
+		if err := rows.Scan(&kind, &count); err != nil {
+			return nil, err
+		}
+		fields[kind] = count
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return fields, nil
+}
+
+func (workspace *Workspace) closeAndDelete() error {
+	workspace.closeLock.Lock()
+	defer workspace.closeLock.Unlock()
+
+	if workspace.closed {
+		return nil
+	}
+	workspace.closed = true
+
+	if err := workspace.database.Close(); err != nil {
+		return core.E("store.Workspace.closeAndDelete", "close workspace database", err)
+	}
+	for _, path := range []string{workspace.databasePath, workspace.databasePath + "-wal", workspace.databasePath + "-shm"} {
+		if result := workspace.filesystem.Delete(path); !result.OK && workspace.filesystem.Exists(path) {
+			return core.E("store.Workspace.closeAndDelete", "delete workspace file", result.Value.(error))
+		}
+	}
+	return nil
+}
+
+func (storeInstance *Store) commitWorkspaceAggregate(workspaceName string, fields map[string]any) error {
+	if err := ensureJournalSchema(storeInstance.database); err != nil {
+		return core.E("store.Workspace.Commit", "ensure journal schema", err)
+	}
+
+	transaction, err := storeInstance.database.Begin()
+	if err != nil {
+		return core.E("store.Workspace.Commit", "begin transaction", err)
+	}
+
+	committed := false
+	defer func() {
+		if !committed {
+			_ = transaction.Rollback()
+		}
+	}()
+
+	fieldsJSON, err := jsonString(fields, "store.Workspace.Commit", "marshal summary")
+	if err != nil {
+		return err
+	}
+	tagsJSON, err := jsonString(map[string]string{"workspace": workspaceName}, "store.Workspace.Commit", "marshal tags")
+	if err != nil {
+		return err
+	}
+
+	if err := insertJournalEntry(
+		transaction,
+		storeInstance.journalBucket(),
+		workspaceName,
+		fieldsJSON,
+		tagsJSON,
+		time.Now().UnixMilli(),
+	); err != nil {
+		return core.E("store.Workspace.Commit", "insert journal entry", err)
+	}
+
+	if _, err := transaction.Exec(
+		"INSERT INTO "+entriesTableName+" ("+entryGroupColumn+", "+entryKeyColumn+", "+entryValueColumn+", expires_at) VALUES (?, ?, ?, NULL) "+
+			"ON CONFLICT("+entryGroupColumn+", "+entryKeyColumn+") DO UPDATE SET "+entryValueColumn+" = excluded."+entryValueColumn+", expires_at = NULL",
+		workspaceSummaryGroup(workspaceName),
+		"summary",
+		fieldsJSON,
+	); err != nil {
+		return core.E("store.Workspace.Commit", "upsert workspace summary", err)
+	}
+
+	if err := transaction.Commit(); err != nil {
+		return core.E("store.Workspace.Commit", "commit transaction", err)
+	}
+	committed = true
+	return nil
+}
+
+func openWorkspaceDatabase(databasePath string) (*sql.DB, error) {
+	workspaceDatabase, err := sql.Open("sqlite", databasePath)
+	if err != nil {
+		return nil, err
+	}
+	workspaceDatabase.SetMaxOpenConns(1)
+	if _, err := workspaceDatabase.Exec("PRAGMA journal_mode=WAL"); err != nil {
+		workspaceDatabase.Close()
+		return nil, err
+	}
+	if _, err := workspaceDatabase.Exec("PRAGMA busy_timeout=5000"); err != nil {
+		workspaceDatabase.Close()
+		return nil, err
+	}
+	if _, err := workspaceDatabase.Exec(createWorkspaceEntriesTableSQL); err != nil {
+		workspaceDatabase.Close()
+		return nil, err
+	}
+	return workspaceDatabase, nil
+}
+
+func workspaceSummaryGroup(workspaceName string) string {
+	return core.Concat(workspaceIdentityGroupName, ":", workspaceName)
+}
+
+func workspaceFilePath(stateDirectory, name string) string {
+	return joinPath(stateDirectory, core.Concat(name, ".duckdb"))
+}
+
+func joinPath(base, name string) string {
+	if base == "" {
+		return name
+	}
+	return core.Concat(core.TrimSuffix(base, "/"), "/", name)
+}
diff --git a/workspace_test.go b/workspace_test.go
new file mode 100644
index 0000000..214afe8
--- /dev/null
+++ b/workspace_test.go
@@ -0,0 +1,121 @@
+package store
+
+import (
+	"testing"
+
+	core "dappco.re/go/core"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestWorkspace_NewWorkspace_Good_CreatePutAggregateQuery(t *testing.T) {
+	stateDirectory := useWorkspaceStateDirectory(t)
+
+	storeInstance, err := New(":memory:", WithJournal("http://127.0.0.1:8086", "core", "events"))
+	require.NoError(t, err)
+	defer storeInstance.Close()
+
+	workspace, err := storeInstance.NewWorkspace("scroll-session")
+	require.NoError(t, err)
+	defer workspace.Discard()
+
+	assert.Equal(t, workspaceFilePath(stateDirectory, "scroll-session"), workspace.databasePath)
+	assert.True(t, testFilesystem().Exists(workspace.databasePath))
+
+	require.NoError(t, workspace.Put("like", map[string]any{"user": "@alice"}))
+	require.NoError(t, workspace.Put("like", map[string]any{"user": "@bob"}))
+	require.NoError(t, workspace.Put("profile_match", map[string]any{"user": "@charlie"}))
+
+	assert.Equal(t, map[string]any{"like": 2, "profile_match": 1}, workspace.Aggregate())
+
+	rows := requireResultRows(
+		t,
+		workspace.Query("SELECT entry_kind, COUNT(*) AS entry_count FROM workspace_entries GROUP BY entry_kind ORDER BY entry_kind"),
+	)
+	require.Len(t, rows, 2)
+	assert.Equal(t, "like", rows[0]["entry_kind"])
+	assert.Equal(t, int64(2), rows[0]["entry_count"])
+	assert.Equal(t, "profile_match", rows[1]["entry_kind"])
+	assert.Equal(t, int64(1), rows[1]["entry_count"])
+}
+
+func TestWorkspace_Commit_Good_JournalAndSummary(t *testing.T) {
+	useWorkspaceStateDirectory(t)
+
+	storeInstance, err := New(":memory:", WithJournal("http://127.0.0.1:8086", "core", "events"))
+	require.NoError(t, err)
+	defer storeInstance.Close()
+
+	workspace, err := storeInstance.NewWorkspace("scroll-session")
+	require.NoError(t, err)
+
+	require.NoError(t, workspace.Put("like", map[string]any{"user": "@alice"}))
+	require.NoError(t, workspace.Put("like", map[string]any{"user": "@bob"}))
+	require.NoError(t, workspace.Put("profile_match", map[string]any{"user": "@charlie"}))
+
+	result := workspace.Commit()
+	require.True(t, result.OK, "workspace commit failed: %v", result.Value)
+	assert.Equal(t, map[string]any{"like": 2, "profile_match": 1}, result.Value)
+	assert.False(t, testFilesystem().Exists(workspace.databasePath))
+
+	summaryJSON, err := storeInstance.Get(workspaceSummaryGroup("scroll-session"), "summary")
+	require.NoError(t, err)
+
+	summary := make(map[string]any)
+	summaryResult := core.JSONUnmarshalString(summaryJSON, &summary)
+	require.True(t, summaryResult.OK, "summary unmarshal failed: %v", summaryResult.Value)
+	assert.Equal(t, float64(2), summary["like"])
+	assert.Equal(t, float64(1), summary["profile_match"])
+
+	rows := requireResultRows(
+		t,
+		storeInstance.QueryJournal(`from(bucket: "events") |> range(start: -24h) |> filter(fn: (r) => r._measurement == "scroll-session")`),
+	)
+	require.Len(t, rows, 1)
+	assert.Equal(t, "scroll-session", rows[0]["measurement"])
+
+	fields, ok := rows[0]["fields"].(map[string]any)
+	require.True(t, ok, "unexpected fields type: %T", rows[0]["fields"])
+	assert.Equal(t, float64(2), fields["like"])
+	assert.Equal(t, float64(1), fields["profile_match"])
+
+	tags, ok := rows[0]["tags"].(map[string]string)
+	require.True(t, ok, "unexpected tags type: %T", rows[0]["tags"])
+	assert.Equal(t, "scroll-session", tags["workspace"])
+}
+
+func TestWorkspace_Discard_Good_Idempotent(t *testing.T) {
+	useWorkspaceStateDirectory(t)
+
+	storeInstance, err := New(":memory:")
+	require.NoError(t, err)
+	defer storeInstance.Close()
+
+	workspace, err := storeInstance.NewWorkspace("discard-session")
+	require.NoError(t, err)
+
+	workspace.Discard()
+	workspace.Discard()
+
+	assert.False(t, testFilesystem().Exists(workspace.databasePath))
+}
+
+func TestWorkspace_RecoverOrphans_Good(t *testing.T) {
+	stateDirectory := useWorkspaceStateDirectory(t)
+
+	storeInstance, err := New(":memory:", WithJournal("http://127.0.0.1:8086", "core", "events"))
+	require.NoError(t, err)
+	defer storeInstance.Close()
+
+	workspace, err := storeInstance.NewWorkspace("orphan-session")
+	require.NoError(t, err)
+	require.NoError(t, workspace.Put("like", map[string]any{"user": "@alice"}))
+	require.NoError(t, workspace.database.Close())
+
+	orphans := storeInstance.RecoverOrphans(stateDirectory)
+	require.Len(t, orphans, 1)
+	assert.Equal(t, map[string]any{"like": 1}, orphans[0].Aggregate())
+
+	orphans[0].Discard()
+	assert.False(t, testFilesystem().Exists(workspaceFilePath(stateDirectory, "orphan-session")))
+}