diff --git a/CHANGELOG.md b/CHANGELOG.md
index d7e8639..4c925ca 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -36,6 +36,7 @@
 - Send: add `send voice` and `send file --ptt` for OGG/Opus WhatsApp voice notes. (#40, #41 — thanks @ricardopolo and @emre6943)
 - Send: accept common phone-number formatting in recipient flags while still storing digits-only WhatsApp JIDs. (#130 — thanks @fahmidme and @ImLukeF)
 - Send: resolve `send text/file --to` against local contacts, groups, and chats, with `--pick` for non-interactive disambiguation. (#122 — thanks @AndroidPoet)
+- Store: add local-only `store stats`, `store cleanup`, `chats cleanup`, and `groups prune` commands with dry-run previews and confirmation gates. (#210, #211 — thanks @thedavidweng)
 
 ### Security
 
diff --git a/README.md b/README.md
index 2ad2ad1..67e6d55 100644
--- a/README.md
+++ b/README.md
@@ -28,6 +28,7 @@ Full docs site: <https://wacli.sh>.
 - [Contacts](docs/contacts.md): `contacts search/show/refresh`, aliases, tags.
 - [Chats](docs/chats.md): `chats list/show`, archive, pin, mute, mark read.
 - [Groups](docs/groups.md): group list, refresh, info, rename, leave, participants, invites, join.
+- [Store](docs/store.md): local store stats and cleanup commands.
 - [Channels](docs/channels.md): `channels list/info/join/leave`, plus sending to channel JIDs.
 - [History](docs/history.md): `history coverage`, `history fill --dry-run`, `history backfill`.
 - [Presence](docs/presence.md): `presence typing/paused`.
@@ -46,7 +47,7 @@ Full docs site: <https://wacli.sh>.
 - **Message tools**: list/search/show/context with chat, sender, direction, time, order, and media-type filters.
 - **Sending**: send text, mentions, quoted replies, stickers, and image/video/audio/document files with captions, MIME override, and custom display filenames. Sends keep a short retry-receipt grace window, and rapid repeated sends warn on stderr.
 - **Media**: download synced message media on demand, or download in the background during auth/sync; send-file uploads and downloads are capped at 100 MiB.
-- **Contacts/chats/groups/channels**: search/show contacts, local aliases/tags, list/show/filter chats, archive/pin/mute/mark-read chats, refresh/list/info/rename groups, manage participants, invite links, join, leave, and manage WhatsApp Channels.
+- **Contacts/chats/groups/store/channels**: search/show contacts, local aliases/tags, list/show/filter chats, archive/pin/mute/mark-read chats, refresh/list/info/rename/prune groups, inspect/prune the local store, manage participants, invite links, join, leave, and manage WhatsApp Channels.
 - **Presence**: send typing/paused indicators.
 - **Profile**: set the authenticated account profile picture from JPEG or PNG input.
 - **Diagnostics + safety**: `doctor`, read-only mode, store locks with lock-owner reporting, lock waiting, owner-only database permissions, panic recovery, reconnect bounds, and bounded media queue backpressure.
@@ -159,6 +160,11 @@ pnpm wacli send react --to 1234567890 --id <message-id>
 pnpm wacli groups list
 pnpm wacli groups rename --jid 123456789@g.us --name "New name"
 
+# Preview local cleanup before deleting stale local rows
+pnpm wacli store stats
+pnpm wacli groups prune --dry-run
+pnpm wacli store cleanup --days 365 --dry-run
+
 # List/join channels and send to a channel JID
 pnpm wacli channels list
 pnpm wacli channels join --invite "https://whatsapp.com/channel/AbCdEfGhIjK"
@@ -212,6 +218,7 @@ Full command docs live under [docs/overview.md](docs/overview.md). Quick referen
 - `wacli chats mute --chat CHAT [--duration DURATION] [--pick N]`
 - `wacli chats unmute --chat CHAT [--pick N]`
 - `wacli chats mark-read|mark-unread --chat CHAT [--pick N]`
+- `wacli chats cleanup [--days N] [--jid JID] [--dry-run] [--confirm]`
 - `wacli groups list [--query TEXT] [--limit N]`
 - `wacli groups refresh`
 - `wacli groups info --jid GROUP_JID`
@@ -220,6 +227,9 @@ Full command docs live under [docs/overview.md](docs/overview.md). Quick referen
 - `wacli groups participants add|remove|promote|demote --jid GROUP_JID --user PHONE_OR_JID`
 - `wacli groups invite link get|revoke --jid GROUP_JID`
 - `wacli groups join --code INVITE_CODE`
+- `wacli groups prune [--days N] [--left-only=false|--include-active] [--dry-run] [--confirm]`
+- `wacli store stats`
+- `wacli store cleanup [--days N] [--dry-run] [--confirm]`
 - `wacli channels list`
 - `wacli channels info --jid CHANNEL_JID`
 - `wacli channels join --invite LINK_OR_CODE`
diff --git a/cmd/wacli/chats.go b/cmd/wacli/chats.go
index 10f27f4..22acddf 100644
--- a/cmd/wacli/chats.go
+++ b/cmd/wacli/chats.go
@@ -33,6 +33,7 @@ func newChatsCmd(flags *rootFlags) *cobra.Command {
 	cmd.AddCommand(newChatsUnmuteCmd(flags))
 	cmd.AddCommand(newChatsMarkReadCmd(flags, true))
 	cmd.AddCommand(newChatsMarkReadCmd(flags, false))
+	cmd.AddCommand(newChatsCleanupCmd(flags))
 	return cmd
 }
 
diff --git a/cmd/wacli/chats_cleanup.go b/cmd/wacli/chats_cleanup.go
new file mode 100644
index 0000000..71c9626
--- /dev/null
+++ b/cmd/wacli/chats_cleanup.go
@@ -0,0 +1,166 @@
+package main
+
+import (
+	"bufio"
+	"context"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/spf13/cobra"
+	"github.com/steipete/wacli/internal/app"
+	"github.com/steipete/wacli/internal/out"
+)
+
+func newChatsCleanupCmd(flags *rootFlags) *cobra.Command {
+	var days int
+	var jid string
+	var dryRun bool
+	var confirm bool
+	cmd := &cobra.Command{
+		Use:   "cleanup",
+		Short: "Clean up old chats from local storage",
+		Long: `Clean up chats that have no recent activity.
+
+By default, removes chats with no messages in the last 365 days.
+Use --days to adjust the threshold. Use --dry-run to preview what would be deleted.`,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if err := flags.requireWritable(); err != nil {
+				return err
+			}
+
+			ctx, cancel := withTimeout(context.Background(), flags)
+			defer cancel()
+
+			a, lk, err := newApp(ctx, flags, true, false)
+			if err != nil {
+				return err
+			}
+			defer closeApp(a, lk)
+
+			if jid != "" {
+				return cleanupSingleChat(ctx, a, jid, dryRun, confirm, flags.asJSON)
+			}
+
+			chats, err := a.DB().ListChatsOlderThan(days)
+			if err != nil {
+				return err
+			}
+
+			if len(chats) == 0 {
+				if flags.asJSON {
+					return out.WriteJSON(os.Stdout, map[string]any{"deleted": 0, "message": "no chats to clean up"})
+				}
+				fmt.Fprintln(os.Stderr, "No chats to clean up.")
+				return nil
+			}
+
+			if dryRun {
+				if flags.asJSON {
+					return out.WriteJSON(os.Stdout, map[string]any{"would_delete": len(chats), "chats": chats})
+				}
+				fmt.Fprintf(os.Stderr, "Would delete %d chat(s):\n", len(chats))
+				for _, c := range chats {
+					name := c.Name
+					if name == "" {
+						name = c.JID
+					}
+					fmt.Fprintf(os.Stderr, "  - %s (%s)\n", name, c.JID)
+				}
+				fmt.Fprintln(os.Stderr, "\nRun without --dry-run to actually delete.")
+				return nil
+			}
+
+			if !confirm {
+				fmt.Fprintf(os.Stderr, "About to delete %d chat(s). This cannot be undone.\n", len(chats))
+				fmt.Fprint(os.Stderr, "Continue? [y/N] ")
+				reader := bufio.NewReader(os.Stdin)
+				answer, _ := reader.ReadString('\n')
+				answer = strings.TrimSpace(strings.ToLower(answer))
+				if answer != "y" && answer != "yes" {
+					fmt.Fprintln(os.Stderr, "Aborted.")
+					return nil
+				}
+			}
+
+			var deleted int
+			for _, c := range chats {
+				msgCount, _ := a.DB().CountChatMessages(c.JID)
+				if err := a.DB().DeleteChat(c.JID); err != nil {
+					fmt.Fprintf(os.Stderr, "Warning: failed to delete chat %s: %v\n", c.JID, err)
+					continue
+				}
+				deleted++
+				if !flags.asJSON {
+					name := c.Name
+					if name == "" {
+						name = c.JID
+					}
+					fmt.Fprintf(os.Stderr, "Deleted %s (%d messages)\n", name, msgCount)
+				}
+			}
+
+			if flags.asJSON {
+				return out.WriteJSON(os.Stdout, map[string]any{"deleted": deleted})
+			}
+			fmt.Fprintf(os.Stderr, "\nDone. Deleted %d chat(s).\n", deleted)
+			return nil
+		},
+	}
+	cmd.Flags().IntVar(&days, "days", 365, "delete chats with no messages in the last N days")
+	cmd.Flags().StringVar(&jid, "jid", "", "delete a specific chat by JID")
+	cmd.Flags().BoolVar(&dryRun, "dry-run", false, "show what would be deleted without deleting")
+	cmd.Flags().BoolVar(&confirm, "confirm", false, "skip confirmation prompt")
+	return cmd
+}
+
+func cleanupSingleChat(ctx context.Context, a *app.App, jid string, dryRun, confirm, asJSON bool) error {
+	chat, err := a.DB().GetChat(jid)
+	if err != nil {
+		return fmt.Errorf("chat not found: %s", jid)
+	}
+
+	msgCount, _ := a.DB().CountChatMessages(jid)
+
+	if dryRun {
+		if asJSON {
+			return out.WriteJSON(os.Stdout, map[string]any{
+				"would_delete":  1,
+				"chat":          chat,
+				"message_count": msgCount,
+			})
+		}
+		name := chat.Name
+		if name == "" {
+			name = chat.JID
+		}
+		fmt.Fprintf(os.Stderr, "Would delete chat: %s (%s, %d messages)\n", name, chat.JID, msgCount)
+		return nil
+	}
+
+	if !confirm {
+		name := chat.Name
+		if name == "" {
+			name = chat.JID
+		}
+		fmt.Fprintf(os.Stderr, "About to delete chat: %s (%s, %d messages). This cannot be undone.\n", name, chat.JID, msgCount)
+		fmt.Fprint(os.Stderr, "Continue? [y/N] ")
+		reader := bufio.NewReader(os.Stdin)
+		answer, _ := reader.ReadString('\n')
+		answer = strings.TrimSpace(strings.ToLower(answer))
+		if answer != "y" && answer != "yes" {
+			fmt.Fprintln(os.Stderr, "Aborted.")
+			return nil
+		}
+	}
+
+	if err := a.DB().DeleteChat(jid); err != nil {
+		return err
+	}
+
+	if asJSON {
+		return out.WriteJSON(os.Stdout, map[string]any{"deleted": 1, "jid": jid, "messages_deleted": msgCount})
+	}
+	fmt.Fprintf(os.Stderr, "Deleted chat %s (%d messages)\n", jid, msgCount)
+	return nil
+}
diff --git a/cmd/wacli/groups.go b/cmd/wacli/groups.go
index 30c333a..a56f264 100644
--- a/cmd/wacli/groups.go
+++ b/cmd/wacli/groups.go
@@ -15,5 +15,6 @@ func newGroupsCmd(flags *rootFlags) *cobra.Command {
 	cmd.AddCommand(newGroupsInviteCmd(flags))
 	cmd.AddCommand(newGroupsJoinCmd(flags))
 	cmd.AddCommand(newGroupsLeaveCmd(flags))
+	cmd.AddCommand(newGroupsPruneCmd(flags))
 	return cmd
 }
diff --git a/cmd/wacli/groups_prune.go b/cmd/wacli/groups_prune.go
new file mode 100644
index 0000000..55f7ee9
--- /dev/null
+++ b/cmd/wacli/groups_prune.go
@@ -0,0 +1,135 @@
+package main
+
+import (
+	"bufio"
+	"context"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/spf13/cobra"
+	"github.com/steipete/wacli/internal/app"
+	"github.com/steipete/wacli/internal/out"
+	"github.com/steipete/wacli/internal/store"
+)
+
+func newGroupsPruneCmd(flags *rootFlags) *cobra.Command {
+	var days int
+	var leftOnly bool
+	var includeActive bool
+	var dryRun bool
+	var confirm bool
+	cmd := &cobra.Command{
+		Use:   "prune",
+		Short: "Remove old or left groups from local storage",
+		Long: `Clean up groups that you have left or that have been inactive.
+
+By default, removes groups you have left. Use --days to prune only left
+groups older than the threshold. Add --include-active to also prune active
+groups whose last local message is older than the threshold.
+
+This only deletes local wacli store rows. It does not leave WhatsApp groups
+or delete anything from WhatsApp servers. Use --dry-run to preview targets.`,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if err := flags.requireWritable(); err != nil {
+				return err
+			}
+			if days < 0 {
+				return fmt.Errorf("days must not be negative")
+			}
+			if !leftOnly {
+				includeActive = true
+			}
+
+			ctx, cancel := withTimeout(context.Background(), flags)
+			defer cancel()
+
+			a, lk, err := newApp(ctx, flags, true, false)
+			if err != nil {
+				return err
+			}
+			defer closeApp(a, lk)
+
+			return pruneGroups(a, days, includeActive, dryRun, confirm, flags.asJSON)
+		},
+	}
+	cmd.Flags().IntVar(&days, "days", 0, "prune groups older than N days (0 = all left groups)")
+	cmd.Flags().BoolVar(&leftOnly, "left-only", true, "only remove groups you have left")
+	cmd.Flags().BoolVar(&includeActive, "include-active", false, "also remove active groups with no messages in the last N days")
+	cmd.Flags().BoolVar(&dryRun, "dry-run", false, "show what would be deleted without deleting")
+	cmd.Flags().BoolVar(&confirm, "confirm", false, "skip confirmation prompt")
+	return cmd
+}
+
+func pruneGroups(a *app.App, days int, includeActive, dryRun, confirm, asJSON bool) error {
+	groups, err := a.DB().ListPrunableGroups(days, includeActive)
+	if err != nil {
+		return err
+	}
+
+	if len(groups) == 0 {
+		if asJSON {
+			return out.WriteJSON(os.Stdout, map[string]any{"deleted": 0, "message": "no groups to prune"})
+		}
+		fmt.Fprintln(os.Stderr, "No groups to prune.")
+		return nil
+	}
+
+	if dryRun {
+		if asJSON {
+			return out.WriteJSON(os.Stdout, map[string]any{"would_delete": len(groups), "groups": groups})
+		}
+		writePruneTargets(os.Stderr, "Would delete", groups)
+		fmt.Fprintln(os.Stderr, "\nRun without --dry-run to actually delete.")
+		return nil
+	}
+
+	if !confirm {
+		fmt.Fprintf(os.Stderr, "About to delete %d group(s) from the local wacli store. This cannot be undone.\n", len(groups))
+		fmt.Fprint(os.Stderr, "Continue? [y/N] ")
+		reader := bufio.NewReader(os.Stdin)
+		answer, _ := reader.ReadString('\n')
+		answer = strings.TrimSpace(strings.ToLower(answer))
+		if answer != "y" && answer != "yes" {
+			fmt.Fprintln(os.Stderr, "Aborted.")
+			return nil
+		}
+	}
+
+	var deleted int
+	for _, g := range groups {
+		if err := a.DB().DeleteGroupLocalData(g.JID); err != nil {
+			fmt.Fprintf(os.Stderr, "Warning: failed to delete group %s: %v\n", g.JID, err)
+			continue
+		}
+		deleted++
+		if !asJSON {
+			name := g.Name
+			if name == "" {
+				name = g.JID
+			}
+			fmt.Fprintf(os.Stderr, "Deleted %s\n", name)
+		}
+	}
+
+	if asJSON {
+		return out.WriteJSON(os.Stdout, map[string]any{"deleted": deleted})
+	}
+	fmt.Fprintf(os.Stderr, "\nDone. Deleted %d group(s).\n", deleted)
+	return nil
+}
+
+func writePruneTargets(w *os.File, prefix string, groups []store.Group) {
+	fmt.Fprintf(w, "%s %d group(s):\n", prefix, len(groups))
+	for _, g := range groups {
+		name := g.Name
+		if name == "" {
+			name = g.JID
+		}
+		state := "left"
+		if g.LeftAt.IsZero() {
+			state = "inactive"
+		}
+		fmt.Fprintf(w, "  - %s (%s, %s)\n", name, g.JID, state)
+	}
+}
diff --git a/cmd/wacli/groups_prune_test.go b/cmd/wacli/groups_prune_test.go
new file mode 100644
index 0000000..76cee8f
--- /dev/null
+++ b/cmd/wacli/groups_prune_test.go
@@ -0,0 +1,117 @@
+package main
+
+import (
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/steipete/wacli/internal/store"
+)
+
+func TestGroupsPruneExposesSafetyFlags(t *testing.T) {
+	cmd := newGroupsPruneCmd(&rootFlags{})
+	for _, name := range []string{"days", "left-only", "include-active", "dry-run", "confirm"} {
+		if cmd.Flags().Lookup(name) == nil {
+			t.Fatalf("expected --%s flag", name)
+		}
+	}
+}
+
+func TestGroupsPruneRejectsReadOnlyBeforeOpeningStore(t *testing.T) {
+	cmd := newGroupsPruneCmd(&rootFlags{readOnly: true})
+	cmd.SetArgs([]string{"--dry-run"})
+	err := cmd.Execute()
+	if err == nil || !strings.Contains(err.Error(), "read-only mode") {
+		t.Fatalf("error = %v, want read-only", err)
+	}
+}
+
+func TestGroupsPruneDryRunDoesNotDeleteOlderLeftGroups(t *testing.T) {
+	storeDir := seedPruneStore(t)
+
+	cmd := newGroupsPruneCmd(&rootFlags{storeDir: storeDir, timeout: time.Minute})
+	cmd.SetArgs([]string{"--days", "180", "--dry-run"})
+	if err := cmd.Execute(); err != nil {
+		t.Fatalf("groups prune dry-run: %v", err)
+	}
+
+	db := openPruneStore(t, storeDir)
+	defer db.Close()
+	if _, err := db.GetChat("old-left@g.us"); err != nil {
+		t.Fatalf("old-left chat should survive dry-run: %v", err)
+	}
+	left, err := db.ListPrunableGroups(180, false)
+	if err != nil {
+		t.Fatalf("ListPrunableGroups: %v", err)
+	}
+	if got := len(left); got != 1 {
+		t.Fatalf("dry-run deleted targets: got %d left, want 1", got)
+	}
+}
+
+func TestGroupsPruneConfirmDeletesOnlyMatchingGroups(t *testing.T) {
+	storeDir := seedPruneStore(t)
+
+	cmd := newGroupsPruneCmd(&rootFlags{storeDir: storeDir, timeout: time.Minute})
+	cmd.SetArgs([]string{"--days", "180", "--confirm"})
+	if err := cmd.Execute(); err != nil {
+		t.Fatalf("groups prune confirm: %v", err)
+	}
+
+	db := openPruneStore(t, storeDir)
+	defer db.Close()
+	if _, err := db.GetChat("old-left@g.us"); err == nil {
+		t.Fatalf("old-left chat should be deleted")
+	}
+	for _, jid := range []string{"recent-left@g.us", "old-active@g.us"} {
+		if _, err := db.GetChat(jid); err != nil {
+			t.Fatalf("%s chat should survive: %v", jid, err)
+		}
+	}
+}
+
+func seedPruneStore(t *testing.T) string {
+	t.Helper()
+	storeDir := t.TempDir()
+	db := openPruneStore(t, storeDir)
+	defer db.Close()
+
+	now := time.Now().UTC()
+	created := now.AddDate(0, 0, -400)
+	oldLeft := now.AddDate(0, 0, -200)
+	recentLeft := now.AddDate(0, 0, -30)
+	oldActive := now.AddDate(0, 0, -220)
+	for _, tc := range []struct {
+		jid    string
+		name   string
+		lastTS time.Time
+		leftAt time.Time
+	}{
+		{"old-left@g.us", "Old Left", oldLeft, oldLeft},
+		{"recent-left@g.us", "Recent Left", recentLeft, recentLeft},
+		{"old-active@g.us", "Old Active", oldActive, time.Time{}},
+	} {
+		if err := db.UpsertGroup(tc.jid, tc.name, "owner@s.whatsapp.net", created); err != nil {
+			t.Fatalf("UpsertGroup %s: %v", tc.jid, err)
+		}
+		if err := db.UpsertChat(tc.jid, "group", tc.name, tc.lastTS); err != nil {
+			t.Fatalf("UpsertChat %s: %v", tc.jid, err)
+		}
+		if !tc.leftAt.IsZero() {
+			if err := db.MarkGroupLeft(tc.jid, tc.leftAt); err != nil {
+				t.Fatalf("MarkGroupLeft %s: %v", tc.jid, err)
+			}
+		}
+	}
+	return storeDir
+}
+
+func openPruneStore(t *testing.T, storeDir string) *store.DB {
+	t.Helper()
+	db, err := store.Open(filepath.Join(storeDir, "wacli.db"))
+	if err != nil {
+		t.Fatalf("Open: %v", err)
+	}
+	return db
+}
diff --git a/cmd/wacli/root.go b/cmd/wacli/root.go
index 6db184f..87c9225 100644
--- a/cmd/wacli/root.go
+++ b/cmd/wacli/root.go
@@ -66,6 +66,7 @@ func execute(args []string) error {
 	rootCmd.AddCommand(newPresenceCmd(&flags))
 	rootCmd.AddCommand(newProfileCmd(&flags))
 	rootCmd.AddCommand(newDocsCmd(&flags))
+	rootCmd.AddCommand(newStoreCmd(&flags))
 
 	rootCmd.SetArgs(args)
 	if err := rootCmd.Execute(); err != nil {
diff --git a/cmd/wacli/store.go b/cmd/wacli/store.go
new file mode 100644
index 0000000..0dd7e72
--- /dev/null
+++ b/cmd/wacli/store.go
@@ -0,0 +1,13 @@
+package main
+
+import "github.com/spf13/cobra"
+
+func newStoreCmd(flags *rootFlags) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "store",
+		Short: "Manage local data store",
+	}
+	cmd.AddCommand(newStoreCleanupCmd(flags))
+	cmd.AddCommand(newStoreStatsCmd(flags))
+	return cmd
+}
diff --git a/cmd/wacli/store_cleanup.go b/cmd/wacli/store_cleanup.go
new file mode 100644
index 0000000..dc8cdee
--- /dev/null
+++ b/cmd/wacli/store_cleanup.go
@@ -0,0 +1,126 @@
+package main
+
+import (
+	"bufio"
+	"context"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/spf13/cobra"
+	"github.com/steipete/wacli/internal/out"
+)
+
+func newStoreCleanupCmd(flags *rootFlags) *cobra.Command {
+	var days int
+	var dryRun bool
+	var confirm bool
+	cmd := &cobra.Command{
+		Use:   "cleanup",
+		Short: "Clean up old data from local store",
+		Long: `Clean up old messages and chats from local storage.
+
+Removes chats with no recent activity and their associated messages.
+Use --days to set the threshold (default: 365 days).
+Use --dry-run to preview what would be deleted.`,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if err := flags.requireWritable(); err != nil {
+				return err
+			}
+
+			ctx, cancel := withTimeout(context.Background(), flags)
+			defer cancel()
+
+			a, lk, err := newApp(ctx, flags, true, false)
+			if err != nil {
+				return err
+			}
+			defer closeApp(a, lk)
+
+			_ = ctx
+
+			chats, err := a.DB().ListChatsOlderThan(days)
+			if err != nil {
+				return err
+			}
+
+			if len(chats) == 0 {
+				if flags.asJSON {
+					return out.WriteJSON(os.Stdout, map[string]any{"deleted": 0, "message": "nothing to clean up"})
+				}
+				fmt.Fprintln(os.Stderr, "Nothing to clean up.")
+				return nil
+			}
+
+			var totalMessages int64
+			for _, c := range chats {
+				count, _ := a.DB().CountChatMessages(c.JID)
+				totalMessages += count
+			}
+
+			if dryRun {
+				if flags.asJSON {
+					return out.WriteJSON(os.Stdout, map[string]any{
+						"would_delete_chats":    len(chats),
+						"would_delete_messages": totalMessages,
+						"days":                  days,
+					})
+				}
+				fmt.Fprintf(os.Stderr, "Would delete %d chat(s) with %d total message(s) (older than %d days):\n", len(chats), totalMessages, days)
+				for _, c := range chats {
+					name := c.Name
+					if name == "" {
+						name = c.JID
+					}
+					count, _ := a.DB().CountChatMessages(c.JID)
+					fmt.Fprintf(os.Stderr, "  - %s (%s, %d messages)\n", name, c.JID, count)
+				}
+				fmt.Fprintln(os.Stderr, "\nRun without --dry-run to actually delete.")
+				return nil
+			}
+
+			if !confirm {
+				fmt.Fprintf(os.Stderr, "About to delete %d chat(s) with %d total message(s). This cannot be undone.\n", len(chats), totalMessages)
+				fmt.Fprint(os.Stderr, "Continue? [y/N] ")
+				reader := bufio.NewReader(os.Stdin)
+				answer, _ := reader.ReadString('\n')
+				answer = strings.TrimSpace(strings.ToLower(answer))
+				if answer != "y" && answer != "yes" {
+					fmt.Fprintln(os.Stderr, "Aborted.")
+					return nil
+				}
+			}
+
+			var deletedChats, deletedMessages int64
+			for _, c := range chats {
+				count, _ := a.DB().CountChatMessages(c.JID)
+				if err := a.DB().DeleteChat(c.JID); err != nil {
+					fmt.Fprintf(os.Stderr, "Warning: failed to delete chat %s: %v\n", c.JID, err)
+					continue
+				}
+				deletedChats++
+				deletedMessages += count
+				if !flags.asJSON {
+					name := c.Name
+					if name == "" {
+						name = c.JID
+					}
+					fmt.Fprintf(os.Stderr, "Deleted %s (%d messages)\n", name, count)
+				}
+			}
+
+			if flags.asJSON {
+				return out.WriteJSON(os.Stdout, map[string]any{
+					"deleted_chats":    deletedChats,
+					"deleted_messages": deletedMessages,
+				})
+			}
+			fmt.Fprintf(os.Stderr, "\nDone. Deleted %d chat(s) with %d message(s).\n", deletedChats, deletedMessages)
+			return nil
+		},
+	}
+	cmd.Flags().IntVar(&days, "days", 365, "delete data older than N days")
+	cmd.Flags().BoolVar(&dryRun, "dry-run", false, "show what would be deleted without deleting")
+	cmd.Flags().BoolVar(&confirm, "confirm", false, "skip confirmation prompt")
+	return cmd
+}
diff --git a/cmd/wacli/store_stats.go b/cmd/wacli/store_stats.go
new file mode 100644
index 0000000..bac911c
--- /dev/null
+++ b/cmd/wacli/store_stats.go
@@ -0,0 +1,68 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+	"github.com/steipete/wacli/internal/out"
+)
+
+func newStoreStatsCmd(flags *rootFlags) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "stats",
+		Short: "Show store statistics",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			ctx, cancel := withTimeout(context.Background(), flags)
+			defer cancel()
+
+			a, lk, err := newApp(ctx, flags, false, false)
+			if err != nil {
+				return err
+			}
+			defer closeApp(a, lk)
+
+			_ = ctx
+
+			chats, err := a.DB().ListChats("", 0)
+			if err != nil {
+				return err
+			}
+
+			groups, err := a.DB().ListGroups("", 0)
+			if err != nil {
+				return err
+			}
+
+			leftGroups, err := a.DB().ListLeftGroups()
+			if err != nil {
+				return err
+			}
+
+			totalMessages, err := a.DB().CountMessages()
+			if err != nil {
+				return err
+			}
+
+			stats := map[string]any{
+				"chats":       len(chats),
+				"groups":      len(groups),
+				"left_groups": len(leftGroups),
+				"messages":    totalMessages,
+			}
+
+			if flags.asJSON {
+				return out.WriteJSON(os.Stdout, stats)
+			}
+
+			fmt.Fprintf(os.Stdout, "Store Statistics:\n")
+			fmt.Fprintf(os.Stdout, "  Chats:       %d\n", len(chats))
+			fmt.Fprintf(os.Stdout, "  Groups:      %d\n", len(groups))
+			fmt.Fprintf(os.Stdout, "  Left Groups: %d\n", len(leftGroups))
+			fmt.Fprintf(os.Stdout, "  Messages:    %d\n", totalMessages)
+			return nil
+		},
+	}
+	return cmd
+}
diff --git a/docs/chats.md b/docs/chats.md
index b484928..76ba859 100644
--- a/docs/chats.md
+++ b/docs/chats.md
@@ -1,6 +1,6 @@
 # chats
 
-Read when: listing known chats, filtering chat state, or archiving/pinning/muting/marking chats.
+Read when: listing known chats, filtering chat state, archiving/pinning/muting/marking chats, or pruning stale local chat rows.
 
 `wacli chats` reads chat rows from `wacli.db`. It can use session-backed PN/LID mappings to make historical `@lid` chat rows display as phone-number chats when possible. State commands send WhatsApp app-state patches through the authenticated session and update the local index after WhatsApp accepts the change.
 
@@ -17,6 +17,7 @@ wacli chats mute --chat CHAT [--duration DURATION] [--pick N]
 wacli chats unmute --chat CHAT [--pick N]
 wacli chats mark-read --chat CHAT [--pick N]
 wacli chats mark-unread --chat CHAT [--pick N]
+wacli chats cleanup [--days N] [--jid JID] [--dry-run] [--confirm]
 ```
 
 ## Notes
@@ -29,6 +30,9 @@ wacli chats mark-unread --chat CHAT [--pick N]
 - State commands print a compact success line by default and a stable JSON object with `--json`.
 - `mute --duration 0` or omitting `--duration` mutes forever. Use `unmute` to clear it.
 - Run `wacli sync` to catch up chat-state changes made on other devices; run `wacli contacts refresh` to improve chat names.
+- `cleanup` only deletes local `wacli.db` rows. It does not delete chats or messages from WhatsApp.
+- `cleanup --days N` skips chats with no known local activity timestamp; use `--jid` for an explicit local row.
+- Use `cleanup --dry-run` before deleting and `--confirm` only for scripts that already reviewed the target list.
 
 ## Examples
 
@@ -39,4 +43,5 @@ wacli chats list --pinned
 wacli chats show --jid 1234567890@s.whatsapp.net
 wacli chats mute --chat "+1 555 123 4567" --duration 8h
 wacli chats mark-read --chat family --pick 1
+wacli chats cleanup --days 365 --dry-run
 ```
diff --git a/docs/groups.md b/docs/groups.md
index 3a7774f..b828248 100644
--- a/docs/groups.md
+++ b/docs/groups.md
@@ -1,6 +1,6 @@
 # groups
 
-Read when: listing, refreshing, inspecting, renaming, joining, leaving, inviting, or managing group participants.
+Read when: listing, refreshing, inspecting, renaming, joining, leaving, inviting, pruning stale local group rows, or managing group participants.
 
 `wacli groups` combines local group rows with live WhatsApp operations. Commands that mutate WhatsApp require writable mode.
 
@@ -19,6 +19,7 @@ wacli groups participants demote --jid GROUP_JID --user PHONE_OR_JID [--user ...
 wacli groups invite link get --jid GROUP_JID
 wacli groups invite link revoke --jid GROUP_JID
 wacli groups join --code INVITE_CODE
+wacli groups prune [--days N] [--left-only=false|--include-active] [--dry-run] [--confirm]
 ```
 
 ## Notes
@@ -29,6 +30,10 @@ wacli groups join --code INVITE_CODE
 - `refresh` fetches joined groups live and updates local rows, including WhatsApp Community hierarchy metadata exposed by whatsmeow.
 - `info` fetches one group live and persists it, including whether the chat is a Community parent or linked subgroup.
 - `leave` marks the group left locally after WhatsApp confirms.
+- `prune` only deletes local group/chat/message rows from `wacli.db`. It does not leave WhatsApp groups or delete anything from WhatsApp servers.
+- `prune` defaults to groups marked left locally. `--days N` limits left-group pruning to groups left more than `N` days ago.
+- `prune --include-active --days N` also targets active groups whose last known local message is older than `N` days. Groups with no known local activity timestamp are skipped.
+- Use `prune --dry-run` before deleting and `--confirm` only after reviewing the target list.
 - Participant users accept phone numbers with common formatting or JIDs.
 - Invite `revoke` resets the invite link.
 
@@ -42,4 +47,5 @@ wacli groups rename --jid 123456789@g.us --name "New name"
 wacli groups participants add --jid 123456789@g.us --user "+1 (234) 567-8900"
 wacli groups invite link get --jid 123456789@g.us
 wacli groups join --code AbCdEfGhIjK
+wacli groups prune --dry-run
 ```
diff --git a/docs/index.md b/docs/index.md
index 6771df5..a066e8a 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -23,6 +23,7 @@ A script-friendly WhatsApp CLI built on [`whatsmeow`](https://github.com/tulir/w
 - **Trying it.** Read [Install](install.md), then [Quickstart](quickstart.md). Pair, sync, and send your first message in under five minutes.
 - **Searching old chats.** Read [Sync](sync.md) for the sync model and [History](history.md) for coverage planning and on-demand backfill.
 - **Managing chat state.** Read [Chats](chats.md) for archive, pin, mute, and read/unread commands.
+- **Managing local storage.** Read [Store](store.md) for stats, dry-run cleanup, and local-only pruning.
 - **Sending from scripts.** Read [Send](send.md) for recipient resolution, channels, replies, mentions, files, and reactions.
 - **Wiring up an agent.** Pair `--read-only`, `--json`, and `--events` from [Overview](overview.md); read [Doctor](doctor.md) for self-checks.
 - **Building companion tools.** Read [Companion integrations](integrations.md) for safe read-only SQLite and JSON integration patterns.
diff --git a/docs/overview.md b/docs/overview.md
index eb5fe08..aa663b6 100644
--- a/docs/overview.md
+++ b/docs/overview.md
@@ -15,6 +15,7 @@ Read when: you need the user-facing command map, global flags, store model, or l
 - Write commands acquire the store lock; use `--lock-wait DURATION` to wait.
 - Use `--read-only` or `WACLI_READONLY=1` to reject commands that write WhatsApp or local state.
 - Use `sync --max-messages`, `sync --max-db-size`, `WACLI_SYNC_MAX_MESSAGES`, or `WACLI_SYNC_MAX_DB_SIZE` to bound local history growth.
+- Use `store cleanup`, `chats cleanup`, and `groups prune` to preview and remove stale local rows after sync has already stored them.
 - Authenticated startup resolves historical `@lid` chat/message rows to phone-number JIDs when the WhatsApp session store has the mapping.
 - Companion tools should prefer `--json`, `--events`, webhooks, or read-only access to `wacli.db`; see [companion integrations](integrations.md).
 
@@ -28,6 +29,7 @@ Read when: you need the user-facing command map, global flags, store model, or l
 - [contacts](contacts.md) - search contacts and manage local aliases/tags.
 - [chats](chats.md) - list, show, filter, and manage known chat state.
 - [groups](groups.md) - refresh, inspect, rename, leave, join, invite, and manage participants.
+- [store](store.md) - inspect local store stats and prune stale local rows.
 - [channels](channels.md) - list, inspect, join, leave, and send to WhatsApp Channels.
 - [history](history.md) - inspect archive coverage and request older per-chat history from the primary device.
 - [presence](presence.md) - send typing/paused indicators.
diff --git a/docs/store.md b/docs/store.md
new file mode 100644
index 0000000..de5ec4c
--- /dev/null
+++ b/docs/store.md
@@ -0,0 +1,42 @@
+# store
+
+Read when: inspecting local SQLite size/counts or pruning old local chat/group rows.
+
+`wacli store` manages the local `wacli.db` mirror. Cleanup commands only delete local wacli cache/history rows; they do not delete WhatsApp chats, leave groups, or remove messages from WhatsApp servers.
+
+## Commands
+
+```bash
+wacli store stats
+wacli store cleanup [--days N] [--dry-run] [--confirm]
+```
+
+Related cleanup commands:
+
+```bash
+wacli chats cleanup [--days N] [--jid JID] [--dry-run] [--confirm]
+wacli groups prune [--days N] [--left-only=false|--include-active] [--dry-run] [--confirm]
+```
+
+## Notes
+
+- `store stats` reads local counts for chats, groups, left groups, and messages.
+- `store cleanup` removes chats whose known local activity is older than `--days` and deletes their messages through the SQLite chat/message cascade.
+- `chats cleanup --jid JID` removes one local chat row and its local messages.
+- `groups prune` removes local group metadata plus the matching local chat/messages for pruned group JIDs.
+- `groups prune` defaults to groups you have left. `--days N` limits that to groups left more than `N` days ago.
+- `groups prune --include-active --days N` also prunes active groups whose last known local message is older than `N` days. Groups with no known local activity timestamp are skipped.
+- Destructive cleanup commands require confirmation unless `--confirm` is passed.
+- Use `--dry-run` first; it lists what would be deleted without changing the local store.
+- Use `--read-only` or `WACLI_READONLY=1` to make cleanup commands fail before opening the store for writes.
+
+## Examples
+
+```bash
+wacli store stats
+wacli store cleanup --days 365 --dry-run
+wacli chats cleanup --jid 1234567890@s.whatsapp.net --dry-run
+wacli groups prune --dry-run
+wacli groups prune --days 180 --dry-run
+wacli groups prune --include-active --days 365 --dry-run
+```
diff --git a/internal/store/chats.go b/internal/store/chats.go
index 3361dc4..035665d 100644
--- a/internal/store/chats.go
+++ b/internal/store/chats.go
@@ -1,6 +1,7 @@
 package store
 
 import (
+	"fmt"
 	"strings"
 	"time"
 )
@@ -142,3 +143,103 @@ func (d *DB) SetChatUnread(jid string, unread bool) error {
 	`, jid, boolToInt(unread))
 	return err
 }
+
+func (d *DB) DeleteChat(jid string) error {
+	jid = strings.TrimSpace(jid)
+	if jid == "" {
+		return fmt.Errorf("chat JID is required")
+	}
+	_, err := d.sql.Exec(`DELETE FROM chats WHERE jid = ?`, jid)
+	return err
+}
+
+func (d *DB) DeleteChatsOlderThan(days int) (int64, error) {
+	if days <= 0 {
+		return 0, fmt.Errorf("days must be positive")
+	}
+	cutoff := nowUTC().AddDate(0, 0, -days)
+	res, err := d.sql.Exec(`
+		DELETE FROM chats
+		WHERE jid IN (
+			SELECT jid FROM (
+				SELECT
+					c.jid,
+					CASE
+						WHEN COALESCE(MAX(m.ts), 0) > COALESCE(c.last_message_ts, 0) THEN COALESCE(MAX(m.ts), 0)
+						ELSE COALESCE(c.last_message_ts, 0)
+					END AS activity_ts
+				FROM chats c
+				LEFT JOIN messages m ON m.chat_jid = c.jid
+				GROUP BY c.jid
+			)
+			WHERE activity_ts > 0 AND activity_ts < ?
+		)
+	`, unix(cutoff))
+	if err != nil {
+		return 0, err
+	}
+	return res.RowsAffected()
+}
+
+func (d *DB) ListChatsOlderThan(days int) ([]Chat, error) {
+	if days <= 0 {
+		return nil, fmt.Errorf("days must be positive")
+	}
+	cutoff := nowUTC().AddDate(0, 0, -days)
+	rows, err := d.sql.Query(`
+		SELECT jid, kind, name, last_message_ts, archived, pinned, muted_until, unread
+		FROM (
+			SELECT
+				c.jid,
+				c.kind,
+				COALESCE(c.name,'') AS name,
+				COALESCE(c.last_message_ts,0) AS last_message_ts,
+				COALESCE(c.archived,0) AS archived,
+				COALESCE(c.pinned,0) AS pinned,
+				COALESCE(c.muted_until,0) AS muted_until,
+				COALESCE(c.unread,0) AS unread,
+				CASE
+					WHEN COALESCE(MAX(m.ts), 0) > COALESCE(c.last_message_ts, 0) THEN COALESCE(MAX(m.ts), 0)
+					ELSE COALESCE(c.last_message_ts, 0)
+				END AS activity_ts
+			FROM chats c
+			LEFT JOIN messages m ON m.chat_jid = c.jid
+			GROUP BY c.jid
+		)
+		WHERE activity_ts > 0 AND activity_ts < ?
+		ORDER BY activity_ts ASC
+	`, unix(cutoff))
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var out []Chat
+	for rows.Next() {
+		var c Chat
+		var ts int64
+		var archived, pinned, unread int
+		if err := rows.Scan(&c.JID, &c.Kind, &c.Name, &ts, &archived, &pinned, &c.MutedUntil, &unread); err != nil {
+			return nil, err
+		}
+		c.LastMessageTS = fromUnix(ts)
+		c.Archived = archived != 0
+		c.Pinned = pinned != 0
+		c.Unread = unread != 0
+		out = append(out, c)
+	}
+	return out, rows.Err()
+}
+
+func (d *DB) CountChatMessages(jid string) (int64, error) {
+	jid = strings.TrimSpace(jid)
+	if jid == "" {
+		return 0, fmt.Errorf("chat JID is required")
+	}
+	row := d.sql.QueryRow(`SELECT COUNT(1) FROM messages WHERE chat_jid = ?`, jid)
+	var n int64
+	if err := row.Scan(&n); err != nil {
+		return 0, err
+	}
+	return n, nil
+}
diff --git a/internal/store/cleanup_test.go b/internal/store/cleanup_test.go
new file mode 100644
index 0000000..e2a0715
--- /dev/null
+++ b/internal/store/cleanup_test.go
@@ -0,0 +1,420 @@
+package store
+
+import (
+	"testing"
+	"time"
+)
+
+func TestDeleteChat(t *testing.T) {
+	db := openTestDB(t)
+
+	now := time.Date(2024, 1, 1, 0, 0, 0, 0, time.UTC)
+	if err := db.UpsertChat("123@s.whatsapp.net", "dm", "Alice", now); err != nil {
+		t.Fatalf("UpsertChat: %v", err)
+	}
+
+	if err := db.UpsertMessage(UpsertMessageParams{
+		ChatJID:   "123@s.whatsapp.net",
+		MsgID:     "msg1",
+		Timestamp: now,
+		Text:      "hello",
+	}); err != nil {
+		t.Fatalf("UpsertMessage: %v", err)
+	}
+
+	msgCount, err := db.CountChatMessages("123@s.whatsapp.net")
+	if err != nil {
+		t.Fatalf("CountChatMessages: %v", err)
+	}
+	if msgCount != 1 {
+		t.Fatalf("expected 1 message, got %d", msgCount)
+	}
+
+	if err := db.DeleteChat("123@s.whatsapp.net"); err != nil {
+		t.Fatalf("DeleteChat: %v", err)
+	}
+
+	_, err = db.GetChat("123@s.whatsapp.net")
+	if err == nil {
+		t.Fatal("expected error after delete, got nil")
+	}
+
+	msgCount, err = db.CountChatMessages("123@s.whatsapp.net")
+	if err != nil {
+		t.Fatalf("CountChatMessages after delete: %v", err)
+	}
+	if msgCount != 0 {
+		t.Fatalf("expected 0 messages after delete, got %d", msgCount)
+	}
+}
+
+func TestDeleteChatsOlderThan(t *testing.T) {
+	db := openTestDB(t)
+
+	now := time.Now().UTC()
+	old := now.AddDate(0, 0, -200)
+	recent := now.AddDate(0, 0, -30)
+
+	if err := db.UpsertChat("old@s.whatsapp.net", "dm", "Old", old); err != nil {
+		t.Fatalf("UpsertChat old: %v", err)
+	}
+	if err := db.UpsertChat("recent@s.whatsapp.net", "dm", "Recent", recent); err != nil {
+		t.Fatalf("UpsertChat recent: %v", err)
+	}
+
+	if err := db.UpsertMessage(UpsertMessageParams{
+		ChatJID:   "old@s.whatsapp.net",
+		MsgID:     "msg1",
+		Timestamp: old,
+		Text:      "old message",
+	}); err != nil {
+		t.Fatalf("UpsertMessage old: %v", err)
+	}
+	if err := db.UpsertMessage(UpsertMessageParams{
+		ChatJID:   "recent@s.whatsapp.net",
+		MsgID:     "msg2",
+		Timestamp: recent,
+		Text:      "recent message",
+	}); err != nil {
+		t.Fatalf("UpsertMessage recent: %v", err)
+	}
+
+	deleted, err := db.DeleteChatsOlderThan(180)
+	if err != nil {
+		t.Fatalf("DeleteChatsOlderThan: %v", err)
+	}
+	if deleted != 1 {
+		t.Fatalf("expected 1 deleted, got %d", deleted)
+	}
+
+	_, err = db.GetChat("old@s.whatsapp.net")
+	if err == nil {
+		t.Fatal("expected old chat to be deleted")
+	}
+
+	c, err := db.GetChat("recent@s.whatsapp.net")
+	if err != nil {
+		t.Fatalf("GetChat recent: %v", err)
+	}
+	if c.JID != "recent@s.whatsapp.net" {
+		t.Fatalf("expected recent chat to survive, got %s", c.JID)
+	}
+}
+
+func TestListChatsOlderThan(t *testing.T) {
+	db := openTestDB(t)
+
+	now := time.Now().UTC()
+	old := now.AddDate(0, 0, -200)
+	recent := now.AddDate(0, 0, -30)
+
+	if err := db.UpsertChat("old@s.whatsapp.net", "dm", "Old", old); err != nil {
+		t.Fatalf("UpsertChat old: %v", err)
+	}
+	if err := db.UpsertChat("recent@s.whatsapp.net", "dm", "Recent", recent); err != nil {
+		t.Fatalf("UpsertChat recent: %v", err)
+	}
+
+	if err := db.UpsertMessage(UpsertMessageParams{
+		ChatJID:   "old@s.whatsapp.net",
+		MsgID:     "msg1",
+		Timestamp: old,
+		Text:      "old message",
+	}); err != nil {
+		t.Fatalf("UpsertMessage old: %v", err)
+	}
+	if err := db.UpsertMessage(UpsertMessageParams{
+		ChatJID:   "recent@s.whatsapp.net",
+		MsgID:     "msg2",
+		Timestamp: recent,
+		Text:      "recent message",
+	}); err != nil {
+		t.Fatalf("UpsertMessage recent: %v", err)
+	}
+
+	chats, err := db.ListChatsOlderThan(180)
+	if err != nil {
+		t.Fatalf("ListChatsOlderThan: %v", err)
+	}
+	if len(chats) != 1 {
+		t.Fatalf("expected 1 chat, got %d", len(chats))
+	}
+	if chats[0].JID != "old@s.whatsapp.net" {
+		t.Fatalf("expected old chat, got %s", chats[0].JID)
+	}
+}
+
+func TestListChatsOlderThanSkipsUnknownActivity(t *testing.T) {
+	db := openTestDB(t)
+
+	if err := db.UpsertChat("unknown@s.whatsapp.net", "dm", "Unknown", time.Time{}); err != nil {
+		t.Fatalf("UpsertChat unknown: %v", err)
+	}
+
+	chats, err := db.ListChatsOlderThan(1)
+	if err != nil {
+		t.Fatalf("ListChatsOlderThan: %v", err)
+	}
+	if len(chats) != 0 {
+		t.Fatalf("expected unknown-activity chat to be skipped, got %#v", chats)
+	}
+
+	deleted, err := db.DeleteChatsOlderThan(1)
+	if err != nil {
+		t.Fatalf("DeleteChatsOlderThan: %v", err)
+	}
+	if deleted != 0 {
+		t.Fatalf("expected 0 deleted, got %d", deleted)
+	}
+}
+
+func TestDeleteGroup(t *testing.T) {
+	db := openTestDB(t)
+
+	created := time.Date(2024, 1, 1, 0, 0, 0, 0, time.UTC)
+	if err := db.UpsertGroup("12345@g.us", "Test Group", "owner@s.whatsapp.net", created); err != nil {
+		t.Fatalf("UpsertGroup: %v", err)
+	}
+
+	if err := db.DeleteGroup("12345@g.us"); err != nil {
+		t.Fatalf("DeleteGroup: %v", err)
+	}
+
+	groups, err := db.ListGroups("", 10)
+	if err != nil {
+		t.Fatalf("ListGroups: %v", err)
+	}
+	if len(groups) != 0 {
+		t.Fatalf("expected 0 groups after delete, got %d", len(groups))
+	}
+}
+
+func TestDeleteGroupLocalDataDeletesGroupChatAndMessages(t *testing.T) {
+	db := openTestDB(t)
+
+	now := time.Date(2024, 1, 1, 0, 0, 0, 0, time.UTC)
+	if err := db.UpsertGroup("12345@g.us", "Test Group", "owner@s.whatsapp.net", now); err != nil {
+		t.Fatalf("UpsertGroup: %v", err)
+	}
+	if err := db.UpsertChat("12345@g.us", "group", "Test Group", now); err != nil {
+		t.Fatalf("UpsertChat: %v", err)
+	}
+	if err := db.UpsertMessage(UpsertMessageParams{
+		ChatJID:   "12345@g.us",
+		MsgID:     "msg1",
+		Timestamp: now,
+		Text:      "hello",
+	}); err != nil {
+		t.Fatalf("UpsertMessage: %v", err)
+	}
+
+	if err := db.DeleteGroupLocalData("12345@g.us"); err != nil {
+		t.Fatalf("DeleteGroupLocalData: %v", err)
+	}
+	if groups, err := db.ListGroups("", 10); err != nil {
+		t.Fatalf("ListGroups: %v", err)
+	} else if len(groups) != 0 {
+		t.Fatalf("expected group deleted, got %#v", groups)
+	}
+	if _, err := db.GetChat("12345@g.us"); err == nil {
+		t.Fatalf("expected chat to be deleted")
+	}
+	if got := countRows(t, db.sql, `SELECT COUNT(1) FROM messages WHERE chat_jid = ?`, "12345@g.us"); got != 0 {
+		t.Fatalf("expected messages deleted, got %d", got)
+	}
+}
+
+func TestListLeftGroups(t *testing.T) {
+	db := openTestDB(t)
+
+	created := time.Date(2024, 1, 1, 0, 0, 0, 0, time.UTC)
+	leftAt := time.Date(2024, 6, 1, 0, 0, 0, 0, time.UTC)
+
+	if err := db.UpsertGroup("active@g.us", "Active Group", "owner@s.whatsapp.net", created); err != nil {
+		t.Fatalf("UpsertGroup active: %v", err)
+	}
+	if err := db.UpsertGroup("left@g.us", "Left Group", "owner@s.whatsapp.net", created); err != nil {
+		t.Fatalf("UpsertGroup left: %v", err)
+	}
+
+	if err := db.MarkGroupLeft("left@g.us", leftAt); err != nil {
+		t.Fatalf("MarkGroupLeft: %v", err)
+	}
+
+	leftGroups, err := db.ListLeftGroups()
+	if err != nil {
+		t.Fatalf("ListLeftGroups: %v", err)
+	}
+	if len(leftGroups) != 1 {
+		t.Fatalf("expected 1 left group, got %d", len(leftGroups))
+	}
+	if leftGroups[0].JID != "left@g.us" {
+		t.Fatalf("expected left@g.us, got %s", leftGroups[0].JID)
+	}
+}
+
+func TestDeleteLeftGroups(t *testing.T) {
+	db := openTestDB(t)
+
+	created := time.Date(2024, 1, 1, 0, 0, 0, 0, time.UTC)
+	leftAt := time.Date(2024, 6, 1, 0, 0, 0, 0, time.UTC)
+
+	if err := db.UpsertGroup("active@g.us", "Active Group", "owner@s.whatsapp.net", created); err != nil {
+		t.Fatalf("UpsertGroup active: %v", err)
+	}
+	if err := db.UpsertGroup("left@g.us", "Left Group", "owner@s.whatsapp.net", created); err != nil {
+		t.Fatalf("UpsertGroup left: %v", err)
+	}
+
+	if err := db.MarkGroupLeft("left@g.us", leftAt); err != nil {
+		t.Fatalf("MarkGroupLeft: %v", err)
+	}
+
+	deleted, err := db.DeleteLeftGroups()
+	if err != nil {
+		t.Fatalf("DeleteLeftGroups: %v", err)
+	}
+	if deleted != 1 {
+		t.Fatalf("expected 1 deleted, got %d", deleted)
+	}
+
+	groups, err := db.ListGroups("", 10)
+	if err != nil {
+		t.Fatalf("ListGroups: %v", err)
+	}
+	if len(groups) != 1 {
+		t.Fatalf("expected 1 active group remaining, got %d", len(groups))
+	}
+	if groups[0].JID != "active@g.us" {
+		t.Fatalf("expected active@g.us, got %s", groups[0].JID)
+	}
+}
+
+func TestDeleteLeftGroupsOlderThan(t *testing.T) {
+	db := openTestDB(t)
+
+	now := time.Now().UTC()
+	created := now.AddDate(0, 0, -365)
+	oldLeft := now.AddDate(0, 0, -200)
+	recentLeft := now.AddDate(0, 0, -30)
+
+	if err := db.UpsertGroup("old-left@g.us", "Old Left", "owner@s.whatsapp.net", created); err != nil {
+		t.Fatalf("UpsertGroup old-left: %v", err)
+	}
+	if err := db.UpsertGroup("recent-left@g.us", "Recent Left", "owner@s.whatsapp.net", created); err != nil {
+		t.Fatalf("UpsertGroup recent-left: %v", err)
+	}
+
+	if err := db.MarkGroupLeft("old-left@g.us", oldLeft); err != nil {
+		t.Fatalf("MarkGroupLeft old: %v", err)
+	}
+	if err := db.MarkGroupLeft("recent-left@g.us", recentLeft); err != nil {
+		t.Fatalf("MarkGroupLeft recent: %v", err)
+	}
+
+	deleted, err := db.DeleteLeftGroupsOlderThan(180)
+	if err != nil {
+		t.Fatalf("DeleteLeftGroupsOlderThan: %v", err)
+	}
+	if deleted != 1 {
+		t.Fatalf("expected 1 deleted, got %d", deleted)
+	}
+
+	leftGroups, err := db.ListLeftGroups()
+	if err != nil {
+		t.Fatalf("ListLeftGroups: %v", err)
+	}
+	if len(leftGroups) != 1 {
+		t.Fatalf("expected 1 left group remaining, got %d", len(leftGroups))
+	}
+	if leftGroups[0].JID != "recent-left@g.us" {
+		t.Fatalf("expected recent-left@g.us, got %s", leftGroups[0].JID)
+	}
+}
+
+func TestListPrunableGroupsHonorsAgeAndIncludeActive(t *testing.T) {
+	db := openTestDB(t)
+
+	now := time.Now().UTC()
+	created := now.AddDate(0, 0, -400)
+	oldLeft := now.AddDate(0, 0, -200)
+	recentLeft := now.AddDate(0, 0, -30)
+	oldActive := now.AddDate(0, 0, -220)
+	recentActive := now.AddDate(0, 0, -10)
+
+	for _, tc := range []struct {
+		jid  string
+		name string
+	}{
+		{"old-left@g.us", "Old Left"},
+		{"recent-left@g.us", "Recent Left"},
+		{"old-active@g.us", "Old Active"},
+		{"recent-active@g.us", "Recent Active"},
+		{"unknown-active@g.us", "Unknown Active"},
+	} {
+		if err := db.UpsertGroup(tc.jid, tc.name, "owner@s.whatsapp.net", created); err != nil {
+			t.Fatalf("UpsertGroup %s: %v", tc.jid, err)
+		}
+	}
+	if err := db.MarkGroupLeft("old-left@g.us", oldLeft); err != nil {
+		t.Fatalf("MarkGroupLeft old: %v", err)
+	}
+	if err := db.MarkGroupLeft("recent-left@g.us", recentLeft); err != nil {
+		t.Fatalf("MarkGroupLeft recent: %v", err)
+	}
+	if err := db.UpsertChat("old-active@g.us", "group", "Old Active", oldActive); err != nil {
+		t.Fatalf("UpsertChat old active: %v", err)
+	}
+	if err := db.UpsertChat("recent-active@g.us", "group", "Recent Active", recentActive); err != nil {
+		t.Fatalf("UpsertChat recent active: %v", err)
+	}
+
+	leftOnly, err := db.ListPrunableGroups(180, false)
+	if err != nil {
+		t.Fatalf("ListPrunableGroups left only: %v", err)
+	}
+	if got, want := groupJIDs(leftOnly), []string{"old-left@g.us"}; !sameStrings(got, want) {
+		t.Fatalf("left-only targets = %#v, want %#v", got, want)
+	}
+
+	withActive, err := db.ListPrunableGroups(180, true)
+	if err != nil {
+		t.Fatalf("ListPrunableGroups include active: %v", err)
+	}
+	if got, want := groupJIDs(withActive), []string{"old-left@g.us", "old-active@g.us"}; !sameStrings(got, want) {
+		t.Fatalf("include-active targets = %#v, want %#v", got, want)
+	}
+
+	allLeft, err := db.ListPrunableGroups(0, false)
+	if err != nil {
+		t.Fatalf("ListPrunableGroups all left: %v", err)
+	}
+	if got, want := groupJIDs(allLeft), []string{"old-left@g.us", "recent-left@g.us"}; !sameStrings(got, want) {
+		t.Fatalf("all-left targets = %#v, want %#v", got, want)
+	}
+}
+
+func groupJIDs(groups []Group) []string {
+	out := make([]string, 0, len(groups))
+	for _, g := range groups {
+		out = append(out, g.JID)
+	}
+	return out
+}
+
+func sameStrings(a, b []string) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	seen := make(map[string]int, len(a))
+	for _, s := range a {
+		seen[s]++
+	}
+	for _, s := range b {
+		seen[s]--
+		if seen[s] < 0 {
+			return false
+		}
+	}
+	return true
+}
diff --git a/internal/store/groups.go b/internal/store/groups.go
index 71f2ada..6ea5148 100644
--- a/internal/store/groups.go
+++ b/internal/store/groups.go
@@ -1,6 +1,7 @@
 package store
 
 import (
+	"fmt"
 	"strings"
 	"time"
 )
@@ -154,3 +155,143 @@ func (d *DB) ListGroups(query string, limit int) ([]Group, error) {
 	}
 	return out, rows.Err()
 }
+
+func (d *DB) DeleteGroup(jid string) error {
+	jid = strings.TrimSpace(jid)
+	if jid == "" {
+		return fmt.Errorf("group JID is required")
+	}
+	_, err := d.sql.Exec(`DELETE FROM groups WHERE jid = ?`, jid)
+	return err
+}
+
+func (d *DB) DeleteGroupLocalData(jid string) (err error) {
+	jid = strings.TrimSpace(jid)
+	if jid == "" {
+		return fmt.Errorf("group JID is required")
+	}
+	tx, err := d.sql.Begin()
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if err != nil {
+			_ = tx.Rollback()
+		}
+	}()
+	if _, err = tx.Exec(`DELETE FROM groups WHERE jid = ?`, jid); err != nil {
+		return err
+	}
+	if _, err = tx.Exec(`DELETE FROM chats WHERE jid = ?`, jid); err != nil {
+		return err
+	}
+	return tx.Commit()
+}
+
+func (d *DB) ListLeftGroups() ([]Group, error) {
+	rows, err := d.sql.Query(`
+		SELECT jid, COALESCE(name,''), COALESCE(owner_jid,''), is_parent, COALESCE(linked_parent_jid,''), COALESCE(created_ts,0), COALESCE(left_at,0), updated_at
+		FROM groups
+		WHERE left_at IS NOT NULL
+		ORDER BY left_at DESC
+	`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var out []Group
+	for rows.Next() {
+		var g Group
+		var isParent int
+		var created, left, updated int64
+		if err := rows.Scan(&g.JID, &g.Name, &g.OwnerJID, &isParent, &g.LinkedParentJID, &created, &left, &updated); err != nil {
+			return nil, err
+		}
+		g.IsParent = isParent != 0
+		g.CreatedAt = fromUnix(created)
+		g.LeftAt = fromUnix(left)
+		g.UpdatedAt = fromUnix(updated)
+		out = append(out, g)
+	}
+	return out, rows.Err()
+}
+
+func (d *DB) ListPrunableGroups(days int, includeActive bool) ([]Group, error) {
+	if days < 0 {
+		return nil, fmt.Errorf("days must not be negative")
+	}
+	if includeActive && days <= 0 {
+		return nil, fmt.Errorf("days must be positive when pruning active groups")
+	}
+	cutoff := int64(0)
+	if days > 0 {
+		cutoff = unix(nowUTC().AddDate(0, 0, -days))
+	}
+	rows, err := d.sql.Query(`
+		SELECT jid, name, owner_jid, is_parent, linked_parent_jid, created_ts, left_at, updated_at
+		FROM (
+			SELECT
+				g.jid,
+				COALESCE(g.name,'') AS name,
+				COALESCE(g.owner_jid,'') AS owner_jid,
+				g.is_parent,
+				COALESCE(g.linked_parent_jid,'') AS linked_parent_jid,
+				COALESCE(g.created_ts,0) AS created_ts,
+				COALESCE(g.left_at,0) AS left_at,
+				g.updated_at,
+				CASE
+					WHEN COALESCE(MAX(m.ts), 0) > COALESCE(c.last_message_ts, 0) THEN COALESCE(MAX(m.ts), 0)
+					ELSE COALESCE(c.last_message_ts, 0)
+				END AS activity_ts
+			FROM groups g
+			LEFT JOIN chats c ON c.jid = g.jid
+			LEFT JOIN messages m ON m.chat_jid = g.jid
+			GROUP BY g.jid
+		)
+		WHERE
+			(left_at > 0 AND (? = 0 OR left_at < ?))
+			OR (? = 1 AND left_at = 0 AND activity_ts > 0 AND activity_ts < ?)
+		ORDER BY CASE WHEN left_at > 0 THEN left_at ELSE activity_ts END ASC
+	`, cutoff, cutoff, boolToInt(includeActive), cutoff)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var out []Group
+	for rows.Next() {
+		var g Group
+		var isParent int
+		var created, left, updated int64
+		if err := rows.Scan(&g.JID, &g.Name, &g.OwnerJID, &isParent, &g.LinkedParentJID, &created, &left, &updated); err != nil {
+			return nil, err
+		}
+		g.IsParent = isParent != 0
+		g.CreatedAt = fromUnix(created)
+		g.LeftAt = fromUnix(left)
+		g.UpdatedAt = fromUnix(updated)
+		out = append(out, g)
+	}
+	return out, rows.Err()
+}
+
+func (d *DB) DeleteLeftGroups() (int64, error) {
+	res, err := d.sql.Exec(`DELETE FROM groups WHERE left_at IS NOT NULL`)
+	if err != nil {
+		return 0, err
+	}
+	return res.RowsAffected()
+}
+
+func (d *DB) DeleteLeftGroupsOlderThan(days int) (int64, error) {
+	if days <= 0 {
+		return 0, fmt.Errorf("days must be positive")
+	}
+	cutoff := nowUTC().AddDate(0, 0, -days)
+	res, err := d.sql.Exec(`DELETE FROM groups WHERE left_at IS NOT NULL AND left_at < ?`, unix(cutoff))
+	if err != nil {
+		return 0, err
+	}
+	return res.RowsAffected()
+}