README.md

@@ -175,12 +175,40 @@ needed.
 * `--keep-newer-than <duration>`: With `--prune`, keep snapshots newer than
   this duration instead of only the latest (e.g. `4w`, `30d`, `6mo`, `1y`)
 
-**`snapshot list`**: Show every snapshot known to the destination
+**`snapshot list`**: Show every snapshot known to this host — the union
-store with timestamps and three sizes per snapshot (compressed
+of the local index and the backup destination store — with timestamps
-remote size; total uncompressed chunk size; size of chunks newly
+and three sizes per snapshot (compressed remote size; total
-referenced by that snapshot). The uncompressed and "new chunk"
+uncompressed chunk size; size of chunks newly referenced by that
-columns show `<remote only>` for snapshots not in the local index.
+snapshot).
-* `--json`: Output in JSON format
+
+Listing the destination store does **not** require the age secret key,
+so it works in vaultik's intended configuration, where the backed-up
+host holds only the public key. A host that has lost its local index
+can still see what it has backed up.
+
+What that host cannot see is a remote-only snapshot's name. The
+snapshot ID is hashed at the storage boundary and the manifest records
+only the hash, so hostname and snapshot name exist solely in the local
+index and in the encrypted per-snapshot database. Snapshots found only
+on the destination store are therefore listed as
+`<remote only:<abbreviated remote key>>` and show `<remote only>` in
+the uncompressed and "new chunk" columns, which can only be computed
+from the local index. Their timestamp and compressed size are real,
+read from the manifest.
+
+Snapshots in the local index with no counterpart on the destination
+store are reported below the table as drift, with the `vaultik prune`
+invocation that reconciles them.
+
+If the destination store cannot be listed (unmounted volume,
+permission denied, network down), the command warns, falls back to the
+local index alone, and still exits zero.
+* `--json`: Output in JSON format. Each entry carries `locally_tracked`
+  (whether the snapshot is in the local index), `remote_key` (the full
+  64-character storage key), and `remote_present` (whether it was seen
+  on the destination store, or `null` if the destination could not be
+  listed). The warning about an unlistable destination goes to stderr
+  so stdout stays a single parseable document.
 
 **`snapshot verify`**: Verify snapshot integrity.
 * Default (shallow): checks that all blobs referenced in the manifest exist in storage

TODO.md

@@ -19,6 +19,25 @@ or delete the branch.
 
 # Completed Steps
 
+- 2026-08-09: Made `snapshot list` list the destination store without
+  the private key (issue #64). The listing is now the union of the
+  local index and a single streamed listing of the `metadata/` prefix,
+  with no `age_secret_key` gate — the manifest is unencrypted, so a
+  host holding only the public key can enumerate its own backups and a
+  host that lost its local index can still see them. A remote-only
+  snapshot's hostname and name are deliberately not recovered (they are
+  not recoverable without the private key, and making them so would
+  undo the privacy property tracked in issue #81); such rows are
+  labelled by an abbreviation of their remote key and carry the real
+  timestamp and compressed size from the manifest, with `<remote only>`
+  in the two columns that require the local index. Local-only snapshots
+  are reported as drift, and the hint now names `vaultik prune`, which
+  exists, instead of `vaultik snapshot cleanup`, which does not.
+  `reportRemoteDrift` collapsed into the merged view. Every remote
+  manifest read in the codebase now goes through
+  `downloadManifestByKey`, so issue #81 has one call site to change.
+  Verified with `script/cibuild` and end to end against a `file://`
+  destination with no secret key present.
 - 2026-08-09: Closed the gap between `make lint` and CI (issue #78).
   `script/lint` now runs the digest-pinned `golangci-lint` image taken
   from the `Dockerfile` lint stage, which is the single source of truth

internal/vaultik/helpers.go

@@ -53,18 +53,36 @@ const (
 )
 
 // SnapshotInfo contains information about a snapshot.
-// UncompressedSize and NewChunkSize are populated only when the snapshot
+//
-// is present in the local database; LocallyTracked indicates whether
+// LocallyTracked says which of the two sources this row came from, and
-// those values are meaningful.
+// therefore which fields are meaningful:
+//
+//   - true: the snapshot is in the local index. ID is its human
+//     snapshot ID and UncompressedSize/NewChunkSize are populated.
+//   - false: the snapshot was found only on the destination store. ID
+//     is empty, because the human ID cannot be recovered from remote
+//     storage without the age secret key (see RemoteKey), and
+//     UncompressedSize/NewChunkSize are zero because they are computed
+//     from local index rows that do not exist.
+//
+// RemoteKey is always populated: for a locally tracked snapshot it is
+// the key the snapshot would occupy on the destination store, and for a
+// remote-only snapshot it is the only identifier available.
+//
+// RemotePresent reports whether the snapshot's metadata was seen on the
+// destination store. It is nil when the destination could not be
+// listed, so "absent" and "unknown" stay distinguishable.
 //
 //nolint:tagliatelle // snake_case is the established output format
 type SnapshotInfo struct {
 	ID               types.SnapshotID `json:"id"`
+	RemoteKey        string           `json:"remote_key"`
 	Timestamp        time.Time        `json:"timestamp"`
 	CompressedSize   int64            `json:"compressed_size"`
 	UncompressedSize int64            `json:"uncompressed_size,omitempty"`
 	NewChunkSize     int64            `json:"new_chunk_size,omitempty"`
 	LocallyTracked   bool             `json:"locally_tracked"`
+	RemotePresent    *bool            `json:"remote_present"`
 }
 
 // formatBytes formats bytes in a human-readable format

internal/vaultik/snapshot.go

@@ -9,10 +9,8 @@ import (
 	"regexp"
 	"sort"
 	"strings"
-	"text/tabwriter"
 	"time"
 
-	"sneak.berlin/go/vaultik/internal/database"
 	"sneak.berlin/go/vaultik/internal/log"
 	"sneak.berlin/go/vaultik/internal/snapshot"
 )
@@ -447,243 +445,6 @@ func (v *Vaultik) getSnapshotBlobSizes(snapshotID string) (int64, int64) {
 	return compressed, uncompressed
 }
 
-// ListSnapshots prints the table of snapshots, plus any reconciliation
-// warnings/notes between the local index and the backup destination
-// store.
-//
-// The local index database is always the primary source for the
-// table — it has the human snapshot IDs, timestamps, and per-snapshot
-// stats.
-//
-// If an age secret key is configured AND remote listing succeeds, we
-// cross-reference: any local snapshot whose hashed key isn't visible
-// remotely gets a "local-only" cleanup hint, and any remote key that
-// doesn't correspond to a known local snapshot gets reported in a
-// NOTE.
-//
-// If no age key is set the local machine is assumed write-only
-// (backup-only), so we skip remote listing entirely — there's no
-// value showing keys the user couldn't restore anyway.
-//
-// If remote listing fails (unmounted volume, permission denied,
-// network), we degrade to local-only with a warning. List never
-// fails just because the destination is unreachable.
-func (v *Vaultik) ListSnapshots(jsonOutput bool) error {
-	log.Info("Listing snapshots")
-
-	localSnaps, err := v.Repositories.Snapshots.ListRecent(v.ctx, listRecentLimit)
-	if err != nil {
-		return fmt.Errorf("listing local snapshots: %w", err)
-	}
-
-	snapshots := make([]SnapshotInfo, 0, len(localSnaps))
-	for _, ls := range localSnaps {
-		if ls.CompletedAt == nil {
-			continue
-		}
-
-		snapshots = append(snapshots, v.snapshotInfoFromLocal(ls))
-	}
-
-	sort.Slice(snapshots, func(i, j int) bool {
-		return snapshots[i].Timestamp.After(snapshots[j].Timestamp)
-	})
-
-	if jsonOutput {
-		encoder := json.NewEncoder(v.Stdout)
-		encoder.SetIndent("", "  ")
-
-		return encoder.Encode(snapshots)
-	}
-
-	err = v.printSnapshotTable(snapshots)
-	if err != nil {
-		return err
-	}
-
-	if v.Config.AgeSecretKey == "" {
-		return nil
-	}
-
-	v.reportRemoteDrift(localSnaps)
-
-	return nil
-}
-
-// reportRemoteDrift cross-references local snapshot records against the
-// remote metadata keys and reports local-only records and unknown
-// remote keys. Never fails: remote listing errors degrade to a warning.
-func (v *Vaultik) reportRemoteDrift(localSnaps []*database.Snapshot) {
-	remoteKeys, err := v.listAllRemoteSnapshotKeys()
-	if err != nil {
-		v.UI.Warningf("Could not list backup destination store: %v.", err)
-
-		return
-	}
-
-	localKeys := make(map[string]string, len(localSnaps))
-	for _, ls := range localSnaps {
-		if ls.CompletedAt == nil {
-			continue
-		}
-
-		localKeys[snapshot.RemoteSnapshotKey(ls.ID.String())] = ls.ID.String()
-	}
-
-	remoteSet := make(map[string]bool, len(remoteKeys))
-	for _, k := range remoteKeys {
-		remoteSet[k] = true
-	}
-
-	var localOnly []string
-
-	for key, humanID := range localKeys {
-		if !remoteSet[key] {
-			localOnly = append(localOnly, humanID)
-		}
-	}
-
-	var remoteOnlyCount int
-
-	for key := range remoteSet {
-		if _, ok := localKeys[key]; !ok {
-			remoteOnlyCount++
-		}
-	}
-
-	if len(localOnly) > 0 {
-		v.UI.Warningf("%d local snapshot record(s) not found in backup "+
-			"destination store:", len(localOnly))
-
-		for _, id := range localOnly {
-			v.UI.Infof("%s", v.UI.Snapshot(id))
-		}
-
-		v.UI.Infof("Run 'vaultik snapshot cleanup' to remove stale local records.")
-	}
-
-	if remoteOnlyCount > 0 {
-		v.UI.Noticef("NOTE: %d remote snapshot(s) found in backup destination "+
-			"store but not in local database.", remoteOnlyCount)
-	}
-}
-
-// snapshotInfoFromLocal builds a SnapshotInfo row from a local snapshot
-// record. Failures from any per-snapshot stat query degrade that
-// column to its snapshot-row fallback but never fail the listing.
-func (v *Vaultik) snapshotInfoFromLocal(ls *database.Snapshot) SnapshotInfo {
-	idStr := ls.ID.String()
-
-	totalSize, err := v.Repositories.Snapshots.GetSnapshotTotalCompressedSize(
-		v.ctx, idStr)
-	if err != nil {
-		log.Warn("Failed to get total compressed size", "id", idStr, "error", err)
-
-		totalSize = ls.BlobSize
-	}
-
-	uncompressedSize, err := v.Repositories.Snapshots.GetSnapshotUncompressedChunkSize(
-		v.ctx, idStr)
-	if err != nil {
-		log.Warn("Failed to get uncompressed chunk size", "id", idStr, "error", err)
-	}
-
-	newChunkSize, err := v.Repositories.Snapshots.GetSnapshotNewChunkSize(v.ctx, idStr)
-	if err != nil {
-		log.Warn("Failed to get new chunk size", "id", idStr, "error", err)
-	}
-
-	return SnapshotInfo{
-		ID:               ls.ID,
-		Timestamp:        ls.StartedAt,
-		CompressedSize:   totalSize,
-		UncompressedSize: uncompressedSize,
-		NewChunkSize:     newChunkSize,
-		LocallyTracked:   true,
-	}
-}
-
-// tabPadding is the tabwriter cell padding for the snapshot table.
-const tabPadding = 3
-
-// printSnapshotTable renders the snapshot list as a formatted table
-func (v *Vaultik) printSnapshotTable(snapshots []SnapshotInfo) error {
-	w := tabwriter.NewWriter(v.Stdout, 0, 0, tabPadding, ' ', 0)
-
-	_, err := fmt.Fprintln(w, "CONFIGURED SNAPSHOTS:")
-	if err != nil {
-		return err
-	}
-
-	_, err = fmt.Fprintln(w, "NAME\tPATHS")
-	if err != nil {
-		return err
-	}
-
-	_, err = fmt.Fprintln(w, "────\t─────")
-	if err != nil {
-		return err
-	}
-
-	for _, name := range v.Config.SnapshotNames() {
-		snap := v.Config.Snapshots[name]
-
-		paths := strings.Join(snap.Paths, ", ")
-
-		_, err = fmt.Fprintf(w, "%s\t%s\n", name, paths)
-		if err != nil {
-			return err
-		}
-	}
-
-	_, err = fmt.Fprintln(w)
-	if err != nil {
-		return err
-	}
-
-	_, err = fmt.Fprintln(w, "REMOTE SNAPSHOTS:")
-	if err != nil {
-		return err
-	}
-
-	_, err = fmt.Fprintln(w,
-		"SNAPSHOT ID\tTIMESTAMP\tCOMPRESSED SIZE\t"+
-			"UNCOMPRESSED SIZE\tNEW CHUNK SIZE")
-	if err != nil {
-		return err
-	}
-
-	_, err = fmt.Fprintln(w,
-		"───────────\t─────────\t───────────────\t"+
-			"─────────────────\t──────────────")
-	if err != nil {
-		return err
-	}
-
-	const remoteOnlyCell = "<remote only>"
-	for _, snap := range snapshots {
-		uncompressed := remoteOnlyCell
-		newChunks := remoteOnlyCell
-
-		if snap.LocallyTracked {
-			uncompressed = formatBytes(snap.UncompressedSize)
-			newChunks = formatBytes(snap.NewChunkSize)
-		}
-
-		_, err = fmt.Fprintf(w, "%s\t%s\t%s\t%s\t%s\n",
-			snap.ID,
-			snap.Timestamp.Format("2006-01-02 15:04:05"),
-			formatBytes(snap.CompressedSize),
-			uncompressed,
-			newChunks)
-		if err != nil {
-			return err
-		}
-	}
-
-	return w.Flush()
-}
-
 // SnapshotPurgeOptions contains options for the snapshot purge command.
 type SnapshotPurgeOptions struct {
 	KeepLatest bool // Keep only the most recent snapshot per name
@@ -1123,6 +884,14 @@ func (v *Vaultik) CleanupLocalSnapshots() error {
 // metadata/<remoteKey>/manifest.json.zst. The remoteKey is the double-
 // SHA256 derivation produced by snapshot.RemoteSnapshotKey, not the
 // human snapshot ID. Callers that have a human ID must hash first.
+//
+// This is the only place vaultik reads a manifest off the destination
+// store, deliberately: the manifest is currently stored compressed but
+// unencrypted, which is what lets `snapshot list` enumerate the
+// destination on a host holding no private key. Whether to encrypt it
+// is open (issue #81), and routing every read through here means that
+// decision has exactly one call site to change. Keep it that way — do
+// not open metadata/<key>/manifest.json.zst directly elsewhere.
 func (v *Vaultik) downloadManifestByKey(remoteKey string) (*snapshot.Manifest, error) {
 	manifestPath := fmt.Sprintf("metadata/%s/manifest.json.zst", remoteKey)
 

internal/vaultik/snapshot_list.go

@@ -0,0 +1,486 @@
+package vaultik
+
+import (
+	"encoding/json"
+	"fmt"
+	"sort"
+	"strings"
+	"text/tabwriter"
+	"time"
+
+	"golang.org/x/sync/errgroup"
+	"sneak.berlin/go/vaultik/internal/database"
+	"sneak.berlin/go/vaultik/internal/log"
+	"sneak.berlin/go/vaultik/internal/snapshot"
+)
+
+// remoteOnlyCell fills the table columns that can only be derived from
+// the local index. A snapshot present only on the destination store has
+// no local rows to derive them from.
+const remoteOnlyCell = "<remote only>"
+
+// remoteKeyDisplayLen is how many hex characters of a remote key are
+// shown in the identifier column for a remote-only snapshot. Twelve
+// matches the abbreviation length used elsewhere in the UI and is far
+// past the point of ambiguity for a SHA256 digest.
+const remoteKeyDisplayLen = 12
+
+// maxRemoteOnlyRows caps how many remote-only snapshots a single
+// `snapshot list` will describe. Each one costs a manifest read, so an
+// uncapped listing against a destination holding many thousands of
+// unknown snapshots would be both slow and unbounded in memory. Beyond
+// the cap the table is truncated and the count of omitted snapshots is
+// reported.
+const maxRemoteOnlyRows = 1000
+
+// remoteManifestFetchConcurrency bounds how many manifest reads are in
+// flight at once while describing remote-only snapshots. The listing
+// itself is a single streamed prefix request; only the per-snapshot
+// manifest reads need throttling.
+const remoteManifestFetchConcurrency = 8
+
+// tabPadding is the tabwriter cell padding for the snapshot table.
+const tabPadding = 3
+
+// ListSnapshots prints the table of snapshots known to this host: the
+// union of the local index database and the backup destination store.
+//
+// Remote listing needs no age secret key. A snapshot's manifest
+// (metadata/<remote-key>/manifest.json.zst) is compressed but not
+// encrypted, so a host holding only the public key — the configuration
+// vaultik is designed for — can still enumerate what it has backed up
+// and see each snapshot's timestamp and compressed size.
+//
+// What that host cannot see is a remote-only snapshot's human ID.
+// snapshot.RemoteSnapshotKey is one-way and the manifest stores the
+// hashed key rather than the ID, so hostname and snapshot name live
+// only in the local index and in the encrypted db.zst.age. Remote-only
+// rows are therefore identified by an abbreviation of their remote key,
+// and the two columns that genuinely require the local index
+// (uncompressed size, new chunk size) render as "<remote only>". No
+// attempt is made to recover or fabricate the human ID.
+//
+// Snapshots in the local index with no counterpart on the destination
+// store are reported as drift below the table.
+//
+// If remote listing fails (unmounted volume, permission denied,
+// network), we degrade to local-only with a warning. List never fails
+// just because the destination is unreachable.
+func (v *Vaultik) ListSnapshots(jsonOutput bool) error {
+	log.Info("Listing snapshots")
+
+	localSnaps, err := v.Repositories.Snapshots.ListRecent(v.ctx, listRecentLimit)
+	if err != nil {
+		return fmt.Errorf("listing local snapshots: %w", err)
+	}
+
+	snapshots := make([]SnapshotInfo, 0, len(localSnaps))
+	localKeys := make(map[string]bool, len(localSnaps))
+
+	for _, ls := range localSnaps {
+		if ls.CompletedAt == nil {
+			continue
+		}
+
+		info := v.snapshotInfoFromLocal(ls)
+		localKeys[info.RemoteKey] = true
+		snapshots = append(snapshots, info)
+	}
+
+	listing, remoteErr := v.collectRemoteSnapshots(localKeys)
+	if remoteErr != nil {
+		v.warnRemoteListingFailed(remoteErr, jsonOutput)
+	} else {
+		snapshots = append(snapshots, listing.remoteOnly...)
+		markRemotePresence(snapshots, listing.keys)
+	}
+
+	sort.Slice(snapshots, func(i, j int) bool {
+		return snapshots[i].Timestamp.After(snapshots[j].Timestamp)
+	})
+
+	if jsonOutput {
+		encoder := json.NewEncoder(v.Stdout)
+		encoder.SetIndent("", "  ")
+
+		return encoder.Encode(snapshots)
+	}
+
+	err = v.printSnapshotTable(snapshots)
+	if err != nil {
+		return err
+	}
+
+	if remoteErr == nil {
+		v.reportListDrift(snapshots, listing)
+	}
+
+	return nil
+}
+
+// warnRemoteListingFailed reports an unreachable or unreadable
+// destination store without failing the command: the local index is
+// still worth printing, and `snapshot list` exiting non-zero because a
+// volume is unmounted would be worse than useless.
+//
+// In --json mode the warning goes to stderr rather than through the
+// logger or the UI writer, both of which emit on stdout — the JSON
+// document has to be the only thing on stdout for `snapshot list --json
+// | jq` to work. The failure is also representable in the document
+// itself: every row's remote_present is null when the destination could
+// not be listed.
+func (v *Vaultik) warnRemoteListingFailed(err error, jsonOutput bool) {
+	if jsonOutput {
+		_, _ = fmt.Fprintf(v.Stderr,
+			"Warning: could not list backup destination store: %v. "+
+				"Showing snapshots from the local index only.\n", err)
+
+		return
+	}
+
+	log.Warn("Could not list backup destination store", "error", err)
+	v.UI.Warningf("Could not list backup destination store: %v.", err)
+	v.UI.Infof("Showing snapshots from the local index only.")
+}
+
+// remoteSnapshotListing is the result of one pass over the destination
+// store's metadata/ prefix.
+type remoteSnapshotListing struct {
+	// keys holds every remote snapshot key present on the destination
+	// store, whether or not it is known locally.
+	keys map[string]bool
+
+	// remoteOnly holds one row per remote key with no local
+	// counterpart, built from that snapshot's manifest.
+	remoteOnly []SnapshotInfo
+
+	// omitted counts remote-only keys dropped because describing them
+	// all would have exceeded maxRemoteOnlyRows.
+	omitted int
+
+	// unreadable counts remote-only keys whose manifest could not be
+	// read or decoded.
+	unreadable int
+}
+
+// collectRemoteSnapshots enumerates the destination store and describes
+// every snapshot on it that localKeys does not already account for.
+//
+// The enumeration is a single streamed listing of the metadata/ prefix,
+// so the request count does not scale with the number of snapshots.
+// Manifest reads scale only with the number of snapshots the local
+// index does not already know about, and are capped at
+// maxRemoteOnlyRows.
+func (v *Vaultik) collectRemoteSnapshots(
+	localKeys map[string]bool,
+) (*remoteSnapshotListing, error) {
+	keys, err := v.listAllRemoteSnapshotKeys()
+	if err != nil {
+		return nil, err
+	}
+
+	listing := &remoteSnapshotListing{
+		keys: make(map[string]bool, len(keys)),
+	}
+
+	unknown := make([]string, 0, len(keys))
+
+	for _, key := range keys {
+		listing.keys[key] = true
+
+		if !localKeys[key] {
+			unknown = append(unknown, key)
+		}
+	}
+
+	// Sorted so both the truncation point and the fetch order are
+	// deterministic run to run.
+	sort.Strings(unknown)
+
+	if len(unknown) > maxRemoteOnlyRows {
+		listing.omitted = len(unknown) - maxRemoteOnlyRows
+		unknown = unknown[:maxRemoteOnlyRows]
+	}
+
+	listing.remoteOnly, listing.unreadable = v.describeRemoteOnlySnapshots(unknown)
+
+	return listing, nil
+}
+
+// describeRemoteOnlySnapshots reads the manifest for each supplied
+// remote key and turns it into a table row, returning the rows and the
+// number of keys whose manifest could not be read.
+//
+// A key whose manifest is missing or corrupt is skipped rather than
+// failing the listing: one bad snapshot directory must not hide every
+// other snapshot the user has.
+func (v *Vaultik) describeRemoteOnlySnapshots(keys []string) ([]SnapshotInfo, int) {
+	found := make([]SnapshotInfo, len(keys))
+	ok := make([]bool, len(keys))
+
+	var group errgroup.Group
+
+	group.SetLimit(remoteManifestFetchConcurrency)
+
+	for i, key := range keys {
+		group.Go(func() error {
+			info, err := v.remoteSnapshotInfo(key)
+			if err != nil {
+				log.Warn("Could not describe remote snapshot",
+					"remote_key", key, "error", err)
+
+				return nil
+			}
+
+			found[i] = info
+			ok[i] = true
+
+			return nil
+		})
+	}
+
+	// No goroutine above ever returns an error; failures are recorded
+	// in ok and reported as a count.
+	_ = group.Wait()
+
+	infos := make([]SnapshotInfo, 0, len(keys))
+	unreadable := 0
+
+	for i := range keys {
+		if !ok[i] {
+			unreadable++
+
+			continue
+		}
+
+		infos = append(infos, found[i])
+	}
+
+	return infos, unreadable
+}
+
+// remoteSnapshotInfo builds a table row for a snapshot that exists on
+// the destination store but not in the local index, from the only
+// source available without the private key: the unencrypted manifest.
+//
+// ID is deliberately left zero. Recovering it would mean inverting
+// snapshot.RemoteSnapshotKey, which is not possible, or writing the
+// human ID somewhere unencrypted on the destination, which would undo
+// the privacy property that hashing the key exists to provide (see
+// issue #81). The renderer marks the row as unnamed rather than
+// guessing.
+func (v *Vaultik) remoteSnapshotInfo(remoteKey string) (SnapshotInfo, error) {
+	manifest, err := v.downloadManifestByKey(remoteKey)
+	if err != nil {
+		return SnapshotInfo{}, err
+	}
+
+	timestamp, err := time.Parse(time.RFC3339, manifest.Timestamp)
+	if err != nil {
+		// The snapshot is really there; an unparseable timestamp is not
+		// reason enough to hide it. It sorts to the bottom as the zero
+		// time.
+		log.Warn("Remote manifest has an unparseable timestamp",
+			"remote_key", remoteKey, "timestamp", manifest.Timestamp, "error", err)
+
+		timestamp = time.Time{}
+	}
+
+	return SnapshotInfo{
+		RemoteKey:      remoteKey,
+		Timestamp:      timestamp.UTC(),
+		CompressedSize: manifest.TotalCompressedSize,
+		LocallyTracked: false,
+	}, nil
+}
+
+// markRemotePresence records, for every row, whether its remote key was
+// seen on the destination store during this listing. Only called when
+// the listing succeeded: when it did not, presence stays nil ("not
+// known") rather than being reported as absence.
+func markRemotePresence(snapshots []SnapshotInfo, remoteKeys map[string]bool) {
+	for i := range snapshots {
+		present := remoteKeys[snapshots[i].RemoteKey]
+		snapshots[i].RemotePresent = &present
+	}
+}
+
+// snapshotInfoFromLocal builds a SnapshotInfo row from a local snapshot
+// record. Failures from any per-snapshot stat query degrade that
+// column to its snapshot-row fallback but never fail the listing.
+func (v *Vaultik) snapshotInfoFromLocal(ls *database.Snapshot) SnapshotInfo {
+	idStr := ls.ID.String()
+
+	totalSize, err := v.Repositories.Snapshots.GetSnapshotTotalCompressedSize(
+		v.ctx, idStr)
+	if err != nil {
+		log.Warn("Failed to get total compressed size", "id", idStr, "error", err)
+
+		totalSize = ls.BlobSize
+	}
+
+	uncompressedSize, err := v.Repositories.Snapshots.GetSnapshotUncompressedChunkSize(
+		v.ctx, idStr)
+	if err != nil {
+		log.Warn("Failed to get uncompressed chunk size", "id", idStr, "error", err)
+	}
+
+	newChunkSize, err := v.Repositories.Snapshots.GetSnapshotNewChunkSize(v.ctx, idStr)
+	if err != nil {
+		log.Warn("Failed to get new chunk size", "id", idStr, "error", err)
+	}
+
+	return SnapshotInfo{
+		ID:               ls.ID,
+		RemoteKey:        snapshot.RemoteSnapshotKey(idStr),
+		Timestamp:        ls.StartedAt,
+		CompressedSize:   totalSize,
+		UncompressedSize: uncompressedSize,
+		NewChunkSize:     newChunkSize,
+		LocallyTracked:   true,
+	}
+}
+
+// reportListDrift prints the reconciliation notes the merged table
+// cannot express on its own: local records with no counterpart on the
+// destination store, plus counts of remote snapshots that were
+// unreadable or omitted.
+//
+// This is what remains of the old reportRemoteDrift, and it no longer
+// touches the destination store. Its remote-only half collapsed into
+// the table — those snapshots are rows now, not a footnote count — and
+// its local-only half reads the merge ListSnapshots already computed,
+// so `snapshot list` lists the destination exactly once per invocation.
+func (v *Vaultik) reportListDrift(
+	snapshots []SnapshotInfo, listing *remoteSnapshotListing,
+) {
+	var localOnly []string
+
+	for _, snap := range snapshots {
+		if snap.LocallyTracked && !listing.keys[snap.RemoteKey] {
+			localOnly = append(localOnly, snap.ID.String())
+		}
+	}
+
+	if len(localOnly) > 0 {
+		v.UI.Warningf("%d local snapshot record(s) not found in backup "+
+			"destination store:", len(localOnly))
+
+		for _, id := range localOnly {
+			v.UI.Infof("%s", v.UI.Snapshot(id))
+		}
+
+		v.UI.Infof("Run '%s' to remove stale local records.", pruneCommandHint)
+	}
+
+	if len(listing.remoteOnly) > 0 {
+		v.UI.Noticef("NOTE: %d snapshot(s) on the backup destination store "+
+			"are not in the local index. Their hostname and snapshot name "+
+			"cannot be recovered without the age secret key, so they are "+
+			"listed by remote key.", len(listing.remoteOnly))
+	}
+
+	if listing.unreadable > 0 {
+		v.UI.Warningf("%d remote snapshot(s) could not be described: "+
+			"manifest missing or unreadable.", listing.unreadable)
+	}
+
+	if listing.omitted > 0 {
+		v.UI.Warningf("%d further remote-only snapshot(s) not shown "+
+			"(limit %d per listing).", listing.omitted, maxRemoteOnlyRows)
+	}
+}
+
+// formatRemoteOnlyID renders the identifier cell for a snapshot absent
+// from the local index. Its human ID cannot be recovered without the
+// private key, so the cell shows an abbreviation of the remote key
+// instead. The angle brackets make it obvious this is not a snapshot
+// name, which matters more than compactness: a bare hex string would
+// read as a name the user simply doesn't recognize.
+func formatRemoteOnlyID(remoteKey string) string {
+	short := remoteKey
+	if len(short) > remoteKeyDisplayLen {
+		short = short[:remoteKeyDisplayLen]
+	}
+
+	return "<remote only:" + short + ">"
+}
+
+// printSnapshotTable renders the snapshot list as a formatted table
+func (v *Vaultik) printSnapshotTable(snapshots []SnapshotInfo) error {
+	w := tabwriter.NewWriter(v.Stdout, 0, 0, tabPadding, ' ', 0)
+
+	_, err := fmt.Fprintln(w, "CONFIGURED SNAPSHOTS:")
+	if err != nil {
+		return err
+	}
+
+	_, err = fmt.Fprintln(w, "NAME\tPATHS")
+	if err != nil {
+		return err
+	}
+
+	_, err = fmt.Fprintln(w, "────\t─────")
+	if err != nil {
+		return err
+	}
+
+	for _, name := range v.Config.SnapshotNames() {
+		snap := v.Config.Snapshots[name]
+
+		paths := strings.Join(snap.Paths, ", ")
+
+		_, err = fmt.Fprintf(w, "%s\t%s\n", name, paths)
+		if err != nil {
+			return err
+		}
+	}
+
+	_, err = fmt.Fprintln(w)
+	if err != nil {
+		return err
+	}
+
+	_, err = fmt.Fprintln(w, "REMOTE SNAPSHOTS:")
+	if err != nil {
+		return err
+	}
+
+	_, err = fmt.Fprintln(w,
+		"SNAPSHOT ID\tTIMESTAMP\tCOMPRESSED SIZE\t"+
+			"UNCOMPRESSED SIZE\tNEW CHUNK SIZE")
+	if err != nil {
+		return err
+	}
+
+	_, err = fmt.Fprintln(w,
+		"───────────\t─────────\t───────────────\t"+
+			"─────────────────\t──────────────")
+	if err != nil {
+		return err
+	}
+
+	for _, snap := range snapshots {
+		id := formatRemoteOnlyID(snap.RemoteKey)
+		uncompressed := remoteOnlyCell
+		newChunks := remoteOnlyCell
+
+		if snap.LocallyTracked {
+			id = snap.ID.String()
+			uncompressed = formatBytes(snap.UncompressedSize)
+			newChunks = formatBytes(snap.NewChunkSize)
+		}
+
+		_, err = fmt.Fprintf(w, "%s\t%s\t%s\t%s\t%s\n",
+			id,
+			snap.Timestamp.Format("2006-01-02 15:04:05"),
+			formatBytes(snap.CompressedSize),
+			uncompressed,
+			newChunks)
+		if err != nil {
+			return err
+		}
+	}
+
+	return w.Flush()
+}

internal/vaultik/snapshot_list_test.go

@@ -0,0 +1,533 @@
+package vaultik_test
+
+import (
+	"bytes"
+	"context"
+	"database/sql"
+	"encoding/json"
+	"errors"
+	"io"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/vaultik/internal/config"
+	"sneak.berlin/go/vaultik/internal/database"
+	"sneak.berlin/go/vaultik/internal/log"
+	"sneak.berlin/go/vaultik/internal/snapshot"
+	"sneak.berlin/go/vaultik/internal/storage"
+	"sneak.berlin/go/vaultik/internal/types"
+	"sneak.berlin/go/vaultik/internal/ui"
+	"sneak.berlin/go/vaultik/internal/vaultik"
+)
+
+// errRemoteUnreachable stands in for the real-world reasons a
+// destination store cannot be listed: unmounted volume, permission
+// denied, network down.
+var errRemoteUnreachable = errors.New("permission denied")
+
+// observingStorer wraps testStorer to record how the destination store
+// was used: how many prefix listings were issued (the merged listing
+// must not scale requests with snapshot count) and which object keys
+// were fetched (nothing encrypted may be fetched during a listing).
+// Setting listErr makes every listing fail, simulating an unreachable
+// destination.
+type observingStorer struct {
+	*testStorer
+
+	mu        sync.Mutex
+	listCalls int
+	fetched   []string
+	listErr   error
+}
+
+func newObservingStorer() *observingStorer {
+	return &observingStorer{testStorer: newTestStorer()}
+}
+
+func (s *observingStorer) ListStream(
+	ctx context.Context, prefix string,
+) <-chan storage.ObjectInfo {
+	s.mu.Lock()
+	s.listCalls++
+	failure := s.listErr
+	s.mu.Unlock()
+
+	if failure != nil {
+		ch := make(chan storage.ObjectInfo, 1)
+		ch <- storage.ObjectInfo{Err: failure}
+
+		close(ch)
+
+		return ch
+	}
+
+	return s.testStorer.ListStream(ctx, prefix)
+}
+
+func (s *observingStorer) Get(
+	ctx context.Context, key string,
+) (io.ReadCloser, error) {
+	s.mu.Lock()
+	s.fetched = append(s.fetched, key)
+	s.mu.Unlock()
+
+	return s.testStorer.Get(ctx, key)
+}
+
+// listStreamCalls returns how many prefix listings were issued.
+func (s *observingStorer) listStreamCalls() int {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	return s.listCalls
+}
+
+// fetchedKeys returns a copy of every object key that was read.
+func (s *observingStorer) fetchedKeys() []string {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	return append([]string(nil), s.fetched...)
+}
+
+// listEnv is a Vaultik wired for exercising ListSnapshots: an in-memory
+// index database, an observable in-memory destination store, and
+// captured output.
+//
+// The configuration deliberately has no age secret key. That is the
+// production configuration vaultik is designed for — the backed-up host
+// holds only the public key — and every assertion in this file has to
+// hold in it.
+type listEnv struct {
+	v      *vaultik.Vaultik
+	store  *observingStorer
+	stdout *bytes.Buffer
+	stderr *bytes.Buffer
+}
+
+func newListEnv(t *testing.T) *listEnv {
+	t.Helper()
+
+	ctx := context.Background()
+
+	db, err := database.New(ctx, ":memory:")
+	require.NoError(t, err)
+	t.Cleanup(func() { _ = db.Close() })
+
+	store := newObservingStorer()
+	stdout := &bytes.Buffer{}
+	stderr := &bytes.Buffer{}
+
+	v := &vaultik.Vaultik{
+		Config: &config.Config{
+			AgeSecretKey: "",
+			Snapshots: map[string]config.SnapshotConfig{
+				listConfiguredName: {Paths: []string{"/" + listConfiguredName}},
+			},
+		},
+		Storage:      store,
+		Repositories: database.NewRepositories(db),
+		DB:           db,
+		Stdout:       stdout,
+		Stderr:       stderr,
+		Stdin:        &bytes.Buffer{},
+		UI:           ui.NewWithColor(stdout, false),
+	}
+	v.SetContext(ctx)
+
+	return &listEnv{v: v, store: store, stdout: stdout, stderr: stderr}
+}
+
+// addLocal inserts a completed snapshot into the local index.
+func (e *listEnv) addLocal(t *testing.T, id string, startedAt time.Time) {
+	t.Helper()
+
+	completedAt := startedAt.Add(time.Minute)
+	snap := &database.Snapshot{
+		ID:             types.SnapshotID(id),
+		Hostname:       "testhost",
+		VaultikVersion: testLabel,
+		StartedAt:      startedAt,
+		CompletedAt:    &completedAt,
+	}
+
+	ctx := context.Background()
+	err := e.v.Repositories.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
+		return e.v.Repositories.Snapshots.Create(ctx, tx, snap)
+	})
+	require.NoError(t, err, "creating local snapshot %s", id)
+}
+
+// addRemote writes a manifest to the destination store at the hashed
+// path the production code uses, exactly as a real backup would. Every
+// fixture snapshot has the same compressed size (fiveMegabytes); the
+// tests care about which columns are populated, not about size variety.
+func (e *listEnv) addRemote(
+	t *testing.T, snapshotID string, timestamp time.Time,
+) string {
+	t.Helper()
+
+	remoteKey := snapshot.RemoteSnapshotKey(snapshotID)
+	manifest := &snapshot.Manifest{
+		// Note: the hashed key, never the human ID. That is precisely
+		// why a remote-only snapshot cannot be named.
+		SnapshotID:          remoteKey,
+		Timestamp:           timestamp.UTC().Format(time.RFC3339),
+		BlobCount:           1,
+		TotalCompressedSize: fiveMegabytes,
+		Blobs: []snapshot.BlobInfo{
+			{Hash: testBlobHashA, CompressedSize: fiveMegabytes},
+		},
+	}
+
+	data, err := snapshot.EncodeManifest(manifest, 3)
+	require.NoError(t, err)
+
+	err = e.store.Put(context.Background(),
+		"metadata/"+remoteKey+"/manifest.json.zst", bytes.NewReader(data))
+	require.NoError(t, err)
+
+	return remoteKey
+}
+
+// Fixtures shared across the listing tests.
+const (
+	// listConfiguredName is the one snapshot name in the test config.
+	listConfiguredName = "home"
+	listLocalID        = "testhost_home_2026-03-01T10:00:00Z"
+	listRemoteID       = "otherhost_media_2026-03-02T11:22:33Z"
+	// fiveMegabytes formats as "5.0 MB" through formatBytes.
+	fiveMegabytes = 5 * 1024 * 1024
+)
+
+// TestListSnapshots_RemoteWithoutSecretKey is the regression guard for
+// issue #64: `snapshot list` must read the destination store on a host
+// that holds no private key. If the remote listing is ever gated on
+// age_secret_key again, this fails.
+func TestListSnapshots_RemoteWithoutSecretKey(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	env := newListEnv(t)
+	require.Empty(t, env.v.Config.AgeSecretKey,
+		"this test is meaningless unless the host has no private key")
+
+	timestamp := time.Date(2026, 3, 2, 11, 22, 33, 0, time.UTC)
+	remoteKey := env.addRemote(t, listRemoteID, timestamp)
+
+	err := env.v.ListSnapshots(false)
+	require.NoError(t, err)
+
+	// The destination store was actually read, with a single prefix
+	// listing rather than one request per snapshot.
+	assert.Equal(t, 1, env.store.listStreamCalls(),
+		"expected exactly one prefix listing of the destination store")
+
+	// Nothing encrypted was touched: enumerating snapshots must never
+	// need the age secret key.
+	for _, key := range env.store.fetchedKeys() {
+		assert.NotContains(t, key, ".age",
+			"listing must not read encrypted objects")
+	}
+
+	out := env.stdout.String()
+
+	// The snapshot is identified by an abbreviation of its remote key.
+	assert.Contains(t, out, "<remote only:"+remoteKey[:12]+">")
+
+	// Its human ID is not recoverable and must not be invented.
+	assert.NotContains(t, out, "otherhost")
+	assert.NotContains(t, out, "media")
+
+	// Manifest-derived columns carry real values.
+	assert.Contains(t, out, "2026-03-02 11:22:33")
+	assert.Contains(t, out, "5.0 MB")
+
+	// The two columns that require the local index are marked, not
+	// blank and not zero. ("<remote only:" does not match this needle,
+	// so the count is exactly the two marker cells.)
+	assert.Equal(t, 2, strings.Count(out, remoteOnlyCellText),
+		"expected the uncompressed and new-chunk cells to be marked")
+}
+
+// remoteOnlyCellText is the marker the table puts in columns that can
+// only be computed from the local index.
+const remoteOnlyCellText = "<remote only>"
+
+// TestListSnapshots_RemoteOnlyRowRendering pins the exact row a
+// remote-only snapshot produces, so the "<remote only>" cells and the
+// LocallyTracked == false branch are verified rather than assumed.
+func TestListSnapshots_RemoteOnlyRowRendering(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	env := newListEnv(t)
+
+	timestamp := time.Date(2026, 3, 2, 11, 22, 33, 0, time.UTC)
+	remoteKey := env.addRemote(t, listRemoteID, timestamp)
+
+	err := env.v.ListSnapshots(false)
+	require.NoError(t, err)
+
+	label := "<remote only:" + remoteKey[:12] + ">"
+	row := findTableRow(t, env.stdout.String(), label)
+
+	// Identifier column: the abbreviated remote key, never blank and
+	// visibly not a snapshot name.
+	assert.True(t, strings.HasPrefix(row, label),
+		"identifier column must lead the row: %q", row)
+
+	// Manifest-derived columns: real values, not placeholders.
+	assert.Contains(t, row, "2026-03-02 11:22:33")
+	assert.Contains(t, row, "5.0 MB")
+
+	// Exactly the two local-index-derived columns are marked.
+	assert.Equal(t, 2, strings.Count(row, remoteOnlyCellText),
+		"uncompressed and new-chunk cells must both be marked: %q", row)
+
+	// And the note explaining why the row has no name.
+	assert.Contains(t, env.stdout.String(),
+		"are not in the local index")
+}
+
+// findTableRow returns the single output line containing needle.
+func findTableRow(t *testing.T, out, needle string) string {
+	t.Helper()
+
+	var found []string
+
+	for line := range strings.SplitSeq(out, "\n") {
+		if strings.Contains(line, needle) {
+			found = append(found, line)
+		}
+	}
+
+	require.Len(t, found, 1, "expected exactly one line containing %q", needle)
+
+	return found[0]
+}
+
+// TestListSnapshots_MergesLocalAndRemote checks that both sources land
+// in one table and that a locally tracked snapshot keeps its human ID
+// and its local-index-derived columns.
+func TestListSnapshots_MergesLocalAndRemote(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	env := newListEnv(t)
+
+	localStart := time.Date(2026, 3, 1, 10, 0, 0, 0, time.UTC)
+	env.addLocal(t, listLocalID, localStart)
+	env.addRemote(t, listLocalID, localStart)
+
+	remoteKey := env.addRemote(t, listRemoteID,
+		time.Date(2026, 3, 2, 11, 22, 33, 0, time.UTC))
+
+	err := env.v.ListSnapshots(false)
+	require.NoError(t, err)
+
+	out := env.stdout.String()
+
+	assert.Contains(t, out, listLocalID)
+	assert.Contains(t, out, "<remote only:"+remoteKey[:12]+">")
+
+	// The locally tracked row is not marked as remote-only anywhere.
+	localRow := findTableRow(t, out, listLocalID)
+	assert.NotContains(t, localRow, "<remote only>")
+
+	// The local snapshot is present remotely, so no drift is reported.
+	assert.NotContains(t, out, "not found in backup destination store")
+}
+
+// TestListSnapshots_LocalOnlyReportedAsDrift covers a snapshot in the
+// local index with no counterpart on the destination store, and checks
+// the remediation hint names a command that actually exists.
+func TestListSnapshots_LocalOnlyReportedAsDrift(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	env := newListEnv(t)
+	env.addLocal(t, listLocalID, time.Date(2026, 3, 1, 10, 0, 0, 0, time.UTC))
+
+	err := env.v.ListSnapshots(false)
+	require.NoError(t, err)
+
+	out := env.stdout.String()
+
+	assert.Contains(t, out, listLocalID)
+	assert.Contains(t, out, "1 local snapshot record(s) not found in backup")
+	assert.Contains(t, out, "vaultik prune")
+
+	// There is no `vaultik snapshot cleanup` command; the hint must not
+	// name one.
+	assert.NotContains(t, out, "snapshot cleanup")
+}
+
+// TestListSnapshots_UnreachableRemoteDegrades covers the promise in the
+// doc comment: an unreachable destination is a warning plus local-only
+// output, never a failure.
+func TestListSnapshots_UnreachableRemoteDegrades(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	env := newListEnv(t)
+	env.addLocal(t, listLocalID, time.Date(2026, 3, 1, 10, 0, 0, 0, time.UTC))
+	env.store.listErr = errRemoteUnreachable
+
+	// Zero exit code: the CLI turns a nil return into exit 0.
+	err := env.v.ListSnapshots(false)
+	require.NoError(t, err)
+
+	out := env.stdout.String()
+
+	assert.Contains(t, out, "Could not list backup destination store")
+	assert.Contains(t, out, "permission denied")
+	assert.Contains(t, out, "Showing snapshots from the local index only.")
+
+	// The local index is still shown.
+	assert.Contains(t, out, listLocalID)
+
+	// With no remote listing there is no basis for a drift claim, so
+	// none must be made.
+	assert.NotContains(t, out, "not found in backup destination store")
+}
+
+// TestListSnapshots_UnreadableManifestDoesNotHideOthers checks that one
+// corrupt remote snapshot directory cannot suppress every other
+// snapshot on the destination store.
+func TestListSnapshots_UnreadableManifestDoesNotHideOthers(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	env := newListEnv(t)
+
+	goodKey := env.addRemote(t, listRemoteID,
+		time.Date(2026, 3, 2, 11, 22, 33, 0, time.UTC))
+
+	badKey := snapshot.RemoteSnapshotKey("testhost_broken_2026-03-03T00:00:00Z")
+	err := env.store.Put(context.Background(),
+		"metadata/"+badKey+"/manifest.json.zst",
+		strings.NewReader("this is not a zstd stream"))
+	require.NoError(t, err)
+
+	err = env.v.ListSnapshots(false)
+	require.NoError(t, err)
+
+	out := env.stdout.String()
+
+	assert.Contains(t, out, "<remote only:"+goodKey[:12]+">")
+	assert.NotContains(t, out, "<remote only:"+badKey[:12]+">")
+	assert.Contains(t, out, "1 remote snapshot(s) could not be described")
+}
+
+// listJSONRow mirrors the JSON shape ListSnapshots emits, so the test
+// asserts against the wire format rather than the Go struct.
+//
+//nolint:tagliatelle // snake_case is the established output format
+type listJSONRow struct {
+	ID             string `json:"id"`
+	RemoteKey      string `json:"remote_key"`
+	CompressedSize int64  `json:"compressed_size"`
+	LocallyTracked bool   `json:"locally_tracked"`
+	RemotePresent  *bool  `json:"remote_present"`
+}
+
+// decodeListJSON parses the command's stdout, which must contain
+// nothing but the JSON document.
+func decodeListJSON(t *testing.T, out string) []listJSONRow {
+	t.Helper()
+
+	var rows []listJSONRow
+
+	err := json.Unmarshal([]byte(out), &rows)
+	require.NoError(t, err, "stdout must be parseable JSON: %q", out)
+
+	return rows
+}
+
+// TestListSnapshots_JSONMergedView covers the --json view of all three
+// cases at once: tracked-and-present, tracked-but-missing remotely, and
+// remote-only.
+func TestListSnapshots_JSONMergedView(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	env := newListEnv(t)
+
+	syncedStart := time.Date(2026, 3, 1, 10, 0, 0, 0, time.UTC)
+	env.addLocal(t, listLocalID, syncedStart)
+	env.addRemote(t, listLocalID, syncedStart)
+
+	driftedID := "testhost_home_2026-02-01T10:00:00Z"
+	env.addLocal(t, driftedID, time.Date(2026, 2, 1, 10, 0, 0, 0, time.UTC))
+
+	remoteKey := env.addRemote(t, listRemoteID,
+		time.Date(2026, 3, 2, 11, 22, 33, 0, time.UTC))
+
+	err := env.v.ListSnapshots(true)
+	require.NoError(t, err)
+
+	rows := decodeListJSON(t, env.stdout.String())
+	require.Len(t, rows, 3)
+
+	byKey := make(map[string]listJSONRow, len(rows))
+	for _, row := range rows {
+		byKey[row.RemoteKey] = row
+	}
+
+	synced := byKey[snapshot.RemoteSnapshotKey(listLocalID)]
+	assert.Equal(t, listLocalID, synced.ID)
+	assert.True(t, synced.LocallyTracked)
+	require.NotNil(t, synced.RemotePresent)
+	assert.True(t, *synced.RemotePresent)
+
+	drifted := byKey[snapshot.RemoteSnapshotKey(driftedID)]
+	assert.Equal(t, driftedID, drifted.ID)
+	assert.True(t, drifted.LocallyTracked)
+	require.NotNil(t, drifted.RemotePresent)
+	assert.False(t, *drifted.RemotePresent,
+		"a local-only snapshot must be visible as drift in --json too")
+
+	remoteOnly := byKey[remoteKey]
+	assert.False(t, remoteOnly.LocallyTracked)
+	assert.Empty(t, remoteOnly.ID,
+		"the human ID is unrecoverable and must not be fabricated")
+	assert.Len(t, remoteOnly.RemoteKey, 64,
+		"--json carries the full remote key, not the truncated form")
+	assert.Equal(t, int64(fiveMegabytes), remoteOnly.CompressedSize)
+	require.NotNil(t, remoteOnly.RemotePresent)
+	assert.True(t, *remoteOnly.RemotePresent)
+}
+
+// TestListSnapshots_JSONUnreachableRemote checks that a failed listing
+// does not corrupt the JSON document with warning text, and that
+// "unknown" is reported as null rather than as absence.
+func TestListSnapshots_JSONUnreachableRemote(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	env := newListEnv(t)
+	env.addLocal(t, listLocalID, time.Date(2026, 3, 1, 10, 0, 0, 0, time.UTC))
+	env.store.listErr = errRemoteUnreachable
+
+	err := env.v.ListSnapshots(true)
+	require.NoError(t, err)
+
+	// stdout must be nothing but the JSON document, so the warning has
+	// to go to stderr.
+	rows := decodeListJSON(t, env.stdout.String())
+	require.Len(t, rows, 1)
+
+	assert.Equal(t, listLocalID, rows[0].ID)
+	assert.True(t, rows[0].LocallyTracked)
+	assert.Nil(t, rows[0].RemotePresent,
+		"remote state is unknown when the destination cannot be listed")
+
+	assert.Contains(t, env.stderr.String(),
+		"could not list backup destination store")
+	assert.Contains(t, env.stderr.String(), "permission denied")
+}