Accept a remote key for restore and verify, and document it (closes #124 )

A host restoring after the original is gone has no local index and cannot know a snapshot's human ID; `snapshot list` shows such snapshots only by their remote key. Restore and verify now resolve an identifier to that remote key: a human ID is hashed as before, and a remote key (or an unambiguous leading part of it, as the table prints) is used directly, resolved against the store's metadata listing. Deep verify reads the one snapshot in the exported database rather than filtering by the human ID. Adds an integration test that backs up with one index and hostname, then lists, restores, and deep-verifies from the store with a fresh empty index, a different hostname, and no age_recipients — comparing restored bytes to the source. The empty index is what makes it fail if restore ever needed the original one. Adds a "Restoring on another machine" README section walking the flow end to end, and drops the now-done roadmap item. Model: claude-opus-4-8
Reconcile the schema/migration docs with the code (closes #68 )
2026-09-21 20:00:22 +00:00 · 2026-09-21 21:58:37 +02:00
16 changed files with 420 additions and 220 deletions
@@ -104,7 +104,12 @@ Version: 2025-06-08

 13. Pre-1.0: NEVER write database migrations. There are no live databases
    anywhere — every user's local index can be rebuilt from a fresh full
-    backup. When the schema changes, just change `schema.sql` (and any code
-    that touches the affected tables). The local index is disposable until
-    1.0 ships and is tagged.
+    backup. To change the schema, edit `internal/database/schema/001.sql`
+    (and any code that touches the affected tables) directly; do not add new
+    numbered schema files. Those numbered files and the `schema_migrations`
+    table they populate only bootstrap a fresh database — they are not an
+    upgrade path. The local index is disposable until 1.0 ships and is
+    tagged; once 1.0 is tagged that clause expires and the question of
+    upgrading existing indexes returns. See [`docs/DATAMODEL.md`](docs/DATAMODEL.md)
+    for the full explanation.

@@ -84,6 +84,57 @@ VAULTIK_AGE_SECRET_KEY='AGE-SECRET-KEY-...' vaultik snapshot restore <snapshot-i
 # 0 3 * * * vaultik snapshot create --cron --prune --keep-newer-than 4w
 ```

+## restoring on another machine
+
+Restoring on a host that never ran the backup — a replacement machine
+after the original is gone — is the case vaultik is built for. That host
+needs only three things: the `vaultik` binary, the age **private** key,
+and the storage credentials for the destination. It does **not** need the
+local index, the original config file, or the original hostname.
+
+```sh
+# install
+go install sneak.berlin/go/vaultik/cmd/vaultik@latest
+
+# create a config and point it at the ORIGINAL backup destination
+vaultik config init
+vaultik config set storage_url "s3://bucket/prefix?endpoint=https://s3.example.com"
+vaultik config set s3.access_key_id "..."
+vaultik config set s3.secret_access_key "..."
+
+# see what is on the destination store
+vaultik snapshot list
+```
+
+`snapshot list` reads the destination store without the private key. A
+snapshot that is not in this host's (empty) local index is shown as
+remote-only: its row is identified by `<remote only:...>` rather than by
+a `hostname_name_timestamp` name, because the name lives only in the
+local index and the encrypted database and cannot be recovered from the
+store. Its timestamp and compressed size are real. (See the `snapshot
+list` description under [command details](#command-details) for the full
+explanation.)
+
+Use that remote key — the hex printed inside `<remote only:...>`, or the
+full `remote_key` from `snapshot list --json` — to restore and verify:
+
+```sh
+# restore everything to /tmp/restored, then check every restored file's
+# chunk hashes
+VAULTIK_AGE_SECRET_KEY='AGE-SECRET-KEY-...' \
+  vaultik snapshot restore --verify <remote-key> /tmp/restored
+
+# optionally, deep-verify the snapshot against the store (downloads and
+# cryptographically checks every blob)
+VAULTIK_AGE_SECRET_KEY='AGE-SECRET-KEY-...' \
+  vaultik snapshot verify --deep <remote-key>
+```
+
+`age_recipients` (the public key) is not needed to restore — only the
+private key in `VAULTIK_AGE_SECRET_KEY`. Both the abbreviated key printed
+in the table and the full 64-character key from `--json` are accepted; a
+leading part of the key is enough as long as it is unambiguous.
+
 ---

 ## cli
@@ -245,6 +296,8 @@ local index alone, and still exits zero.
 * Default (shallow): checks that all blobs referenced in the manifest exist in storage
 * `--deep`: Downloads and decrypts each blob, verifies chunk hashes against the
  encrypted metadata database
+* Accepts the same identifiers as `snapshot restore`: a snapshot ID, or a
+  remote-only snapshot's remote key (or an unambiguous leading part of it)
 * `--json`: Output results as JSON

 **`snapshot purge`**: Remove old snapshots based on criteria. Retention is
@@ -275,6 +328,10 @@ on the destination in one go, use `vaultik remote nuke --force`.

 **`snapshot restore`**: Restore files from a backup snapshot.
 * Requires `VAULTIK_AGE_SECRET_KEY` environment variable
+* Accepts a snapshot ID, or — for a snapshot only on the destination
+  store — its remote key (or an unambiguous leading part of it) as shown
+  by `snapshot list`. See
+  [restoring on another machine](#restoring-on-another-machine).
 * Optional path arguments to restore specific files/directories (default: all)
 * Preserves file permissions, timestamps, ownership (ownership requires root),
  symlinks, and empty directories
@@ -457,9 +514,13 @@ Key fields:
  sequentially. Restore speed is bound by single-stream throughput.
 * **Device nodes, named pipes, and sockets are silently skipped.** Only
  regular files, directories, and symlinks are backed up.
-* **No database migrations.** If the local SQLite schema changes between
-  versions, delete the local database (`vaultik database delete`) and run
-  a full backup. Remote storage is unaffected.
+* **No upgrade path between versions.** There is no supported way to carry
+  an existing local index across a schema change; if the local SQLite
+  schema changes between versions, delete the local database (`vaultik
+  database delete`) and run a full backup. Remote storage is unaffected.
+  (The binary does embed numbered schema files and a `schema_migrations`
+  table to bootstrap a fresh database — see [`docs/DATAMODEL.md`](docs/DATAMODEL.md)
+  — but that is not an upgrade path.)
 * **Files that change during backup may be inconsistent.** There is no
  filesystem snapshot or freeze. If a file is modified between the scan
  and chunk phases, the backed-up copy may reflect a partial write.
@@ -525,14 +586,12 @@ priority.

 ### infrastructure

-* **Cross-machine restore documentation.** The "restore from
-  another host" workflow works but isn't documented as a
-  first-class operation in this README. Worth a dedicated section
-  once it's settled.
-* **Schema migrations.** Currently nonexistent — pre-1.0 schema
-  changes are handled by `vaultik database delete` plus a full
-  re-scan. Post-1.0 we'll need a migration story to keep existing
-  index databases usable across upgrades.
+* **Cross-version schema upgrades.** There is no upgrade path between
+  released versions — pre-1.0 schema changes are handled by `vaultik
+  database delete` plus a full re-scan (see
+  [`docs/DATAMODEL.md`](docs/DATAMODEL.md)). Post-1.0 we'll need a
+  migration story to keep existing index databases usable across
+  upgrades.
 * **Storage backend coverage tests.** S3, file://, and rclone://
  all share the Storer interface but the rclone path is the least
  exercised in CI.
@@ -35,17 +35,6 @@ release" is exactly the contradiction
  no `--json` representation — under `--json` the summary is suppressed
  entirely — so nothing there can show a false `0`.

- 2026-09-21: Stopped `--json` from silencing stderr diagnostics
-  ([issue #112](https://git.eeqj.de/sneak/vaultik/issues/112)). `--json`
-  used to be folded into `Quiet`, which pinned the log level to `WARN`,
-  so `prune --json` gave a machine consumer no record of the local index
-  rows it deleted even under `--verbose`. `--json` now quiets only the
-  stdout UI (the JSON document must stay clean, per
-  [issue #108](https://git.eeqj.de/sneak/vaultik/issues/108)); the stderr
-  log level follows `--verbose`/`--debug` again. The coupling was
-  removed the same way for `snapshot verify`, `snapshot remove`, and
-  `remote info`, which carried it for the same outdated reason.
-
 - 2026-09-21: Made the s3 storage backend report a missing object as
  `storage.ErrNotFound`, like the `file` and `rclone` backends and as the
  `Storer` interface documents. `S3Storer.Get` and `Stat` returned the raw
@@ -5,11 +5,30 @@
 Vaultik uses a local SQLite database to track file metadata, chunk mappings, and blob associations during the backup process. This database serves as an index for incremental backups and enables efficient deduplication.

 **Important Notes:**
- **No Migration Support (pre-1.0)**: Vaultik does not support database schema
-  migrations. The local index is treated as disposable — if the schema changes,
-  delete the local SQLite database (`vaultik database delete`) and run a full
-  backup. The remote storage is unaffected; the new index will re-deduplicate
-  against existing remote blobs.
+
+This section is the authoritative explanation of the schema/migration story;
+other documents (the README and `AGENTS.md`) link here.
+
+- **No upgrade path between versions (pre-1.0)**: Vaultik has no supported way to
+  carry an existing local index across a schema change. The index is disposable
+  — if the on-disk schema changes between versions, delete the local SQLite
+  database (`vaultik database delete`) and run a full backup. Remote storage is
+  unaffected; the new index re-deduplicates against existing remote blobs. This
+  is the standing project policy, and it is separate from the schema bootstrap
+  described next.
+- **Schema bootstrap**: a fresh database is populated from numbered SQL files
+  embedded in the binary under `internal/database/schema/`. `000.sql` creates the
+  `schema_migrations` table; `001.sql` creates the application tables. On opening
+  a database the code applies each numbered file that has not yet run and records
+  its version in `schema_migrations`. This bootstraps a new database; it does not
+  upgrade an existing one between released versions.
+- **Changing the schema (pre-1.0)**: edit `internal/database/schema/001.sql` (and
+  the code that touches the affected tables) directly. Do not add new numbered
+  files — there is no installed base to migrate.
+- **Disposability expires at 1.0**: the index is treated as disposable only until
+  1.0 ships and is tagged. Once 1.0 is tagged that clause expires and the
+  question of upgrading existing indexes returns. It is deliberately left open
+  here.
 - **Version Compatibility**: In rare cases, you may need to use the same version
  of Vaultik to restore a backup as was used to create it. This ensures
  compatibility with the metadata format stored in S3.
@@ -48,11 +48,6 @@ type AppOptions struct {
 // silenced — per the documented convention that --quiet suppresses
 // non-error output only. The startup banner is printed by Entry
 // before cobra parses arguments, gated by the same arg-level check.
-//
-// --json quiets the UI here too, because stdout then carries a JSON
-// document and human narration would corrupt it. Unlike Quiet it does
-// not lower the stderr log level (issue #112), so --verbose/--debug
-// still surface diagnostics alongside the document.
 func setupGlobals(
 	lc fx.Lifecycle, g *globals.Globals, v *vaultik.Vaultik, opts log.Options,
 ) {
@@ -60,7 +55,7 @@ func setupGlobals(
 		OnStart: func(_ context.Context) error {
 			g.StartTime = time.Now().UTC()

-			if opts.Cron || opts.Quiet || opts.JSON {
+			if opts.Cron || opts.Quiet {
 				v.UI.SetQuiet(true)
 			}

@@ -207,10 +202,9 @@ func RunApp(ctx context.Context, app *fx.App) error {
 // instance in a goroutine, report a failure prefixed with failMsg
 // (suppressed while suppressErrors is true, e.g. under --json), then
 // trigger shutdown. The operation is cancelled when the app stops.
-// jsonOutput marks a command whose stdout is a JSON document: it quiets
-// the UI but, unlike Quiet, leaves the stderr log level alone.
+// extraQuiet is OR-ed into LogOptions.Quiet (e.g. --json output modes).
 func runVaultikApp(
-	cmd *cobra.Command, jsonOutput, suppressErrors bool,
+	cmd *cobra.Command, extraQuiet, suppressErrors bool,
 	failMsg string, op func(v *vaultik.Vaultik) error,
 ) error {
 	configPath, err := ResolveConfigPath()
@@ -225,8 +219,7 @@ func runVaultikApp(
 		LogOptions: log.Options{
 			Verbose: rootFlags.Verbose,
 			Debug:   rootFlags.Debug,
-			Quiet:   rootFlags.Quiet,
-			JSON:    jsonOutput,
+			Quiet:   rootFlags.Quiet || extraQuiet,
 		},
 		Modules: []fx.Option{},
 		Invokes: []fx.Option{
@@ -1,139 +0,0 @@
-package cli //nolint:testpackage // shares the prune fixtures and capture helpers
-
-import (
-	"bytes"
-	"io"
-	"os"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-// staleRecordLogMessage is the local-cleanup audit line CleanupLocalSnapshots
-// logs for each stale record. It is exactly the signal issue #112 says a
-// machine consumer lost under --json: gated off stdout, and pinned below
-// the log level on stderr because --json used to force Quiet.
-const staleRecordLogMessage = "Removing stale local snapshot record"
-
-// TestEntryPruneJSONStderrHonoursVerbosity is the end-to-end regression
-// guard for issue #112. Under --json the log level must still follow
-// --verbose/--debug rather than being pinned to WARN, so the
-// local-cleanup records reach stderr under --verbose while stdout stays
-// exactly one JSON document; without --verbose they stay below the
-// level, as they do without --json.
-//
-// Both halves are asserted together on the same run, because the fix has
-// to keep the document clean (issue #108) while freeing stderr.
-//
-// Not parallel: it replaces os.Args, os.Stdout, os.Stderr and the xdg
-// globals.
-//
-//nolint:paralleltest // replaces os.Args, os.Stdout, os.Stderr and the xdg globals
-func TestEntryPruneJSONStderrHonoursVerbosity(t *testing.T) {
-	for _, testCase := range []struct {
-		name         string
-		verbose      bool
-		wantOnStderr bool
-	}{
-		{
-			name:         "verbose json surfaces the cleanup record on stderr",
-			verbose:      true,
-			wantOnStderr: true,
-		},
-		{
-			name:         "json alone keeps the cleanup record below the level",
-			verbose:      false,
-			wantOnStderr: false,
-		},
-	} {
-		t.Run(testCase.name, func(t *testing.T) {
-			configPath := writeHermeticPruneConfig(t, true)
-
-			previousArgs := os.Args
-
-			t.Cleanup(func() {
-				os.Args = previousArgs
-				rootFlags = RootFlags{}
-			})
-
-			args := []string{
-				programName, flagConfig, configPath, cmdPrune, flagJSON,
-			}
-			if testCase.verbose {
-				args = append(args, "--verbose")
-			}
-
-			os.Args = args
-
-			stdout, stderr := captureProcessStdoutAndStderr(t, Entry)
-
-			// The document stays clean in both cases: freeing stderr must
-			// not regress issue #108.
-			requireExactlyOneJSONDocument(t, stdout)
-
-			if testCase.wantOnStderr {
-				assert.Contains(t, stderr, staleRecordLogMessage,
-					"--verbose --json must emit the cleanup record on stderr")
-				assert.Contains(t, stderr, stalePruneSnapshotID,
-					"the record must name the snapshot it removed")
-			} else {
-				assert.NotContains(t, stderr, staleRecordLogMessage,
-					"without --verbose the record stays below the log level")
-			}
-		})
-	}
-}
-
-// captureProcessStdoutAndStderr redirects both of the process's own
-// standard streams to pipes for the duration of fn and returns what was
-// written to each. The redirection is at the file-descriptor level
-// because the logger binds os.Stderr when it initializes inside fn, and
-// the JSON document reaches os.Stdout independently; the point is to see
-// where each actually lands.
-//
-// Not parallel-safe: os.Stdout and os.Stderr are process-global.
-func captureProcessStdoutAndStderr(t *testing.T, fn func()) (string, string) {
-	t.Helper()
-
-	outReader, outWriter, err := os.Pipe()
-	require.NoError(t, err)
-
-	errReader, errWriter, err := os.Pipe()
-	require.NoError(t, err)
-
-	previousOut, previousErr := os.Stdout, os.Stderr
-	os.Stdout, os.Stderr = outWriter, errWriter
-
-	capturedOut := drain(outReader)
-	capturedErr := drain(errReader)
-
-	fn()
-
-	os.Stdout, os.Stderr = previousOut, previousErr
-
-	require.NoError(t, outWriter.Close())
-	require.NoError(t, errWriter.Close())
-
-	out, errOut := <-capturedOut, <-capturedErr
-
-	require.NoError(t, outReader.Close())
-	require.NoError(t, errReader.Close())
-
-	return out, errOut
-}
-
-// drain copies a reader to a string on a goroutine and delivers the
-// result once the writer end is closed.
-func drain(reader io.Reader) <-chan string {
-	captured := make(chan string, 1)
-
-	go func() {
-		var buf bytes.Buffer
-
-		_, _ = io.Copy(&buf, reader)
-		captured <- buf.String()
-	}()
-
-	return captured
-}
@@ -46,8 +46,7 @@ work (e.g. after a crashed backup or to reclaim storage).`,
 				LogOptions: log.Options{
 					Verbose: rootFlags.Verbose,
 					Debug:   rootFlags.Debug,
-					Quiet:   rootFlags.Quiet,
-					JSON:    opts.JSON,
+					Quiet:   rootFlags.Quiet || opts.JSON,
 				},
 				Modules: []fx.Option{},
 				Invokes: []fx.Option{
@@ -88,8 +88,7 @@ func newRemoteInfoCommand() *cobra.Command {
 				LogOptions: log.Options{
 					Verbose: rootFlags.Verbose,
 					Debug:   rootFlags.Debug,
-					Quiet:   rootFlags.Quiet,
-					JSON:    jsonOutput,
+					Quiet:   rootFlags.Quiet || jsonOutput,
 				},
 				Modules: []fx.Option{},
 				Invokes: []fx.Option{
@@ -221,8 +221,11 @@ func newSnapshotVerifyCommand() *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "verify <snapshot-id>",
 		Short: "Verify snapshot integrity",
-		Long:  "Verifies that all blobs referenced in a snapshot exist",
-		Args:  requireSnapshotIDArg,
+		Long: "Verifies that all blobs referenced in a snapshot exist.\n\n" +
+			"The snapshot may be named by its ID or, on a host with no local\n" +
+			"index, by the remote key that 'snapshot list' prints for a\n" +
+			"remote-only snapshot (an unambiguous leading part is enough).",
+		Args: requireSnapshotIDArg,
 		RunE: func(cmd *cobra.Command, args []string) error {
 			snapshotID := args[0]

@@ -239,8 +242,7 @@ func newSnapshotVerifyCommand() *cobra.Command {
 				LogOptions: log.Options{
 					Verbose: rootFlags.Verbose,
 					Debug:   rootFlags.Debug,
-					Quiet:   rootFlags.Quiet,
-					JSON:    opts.JSON,
+					Quiet:   rootFlags.Quiet || opts.JSON,
 				},
 				Modules: []fx.Option{},
 				Invokes: []fx.Option{
@@ -48,6 +48,10 @@ target directory.
 If no paths are specified, all files are restored.
 If paths are specified, only matching files/directories are restored.

+The snapshot may be named by its ID or, when restoring on a host with no
+local index, by the remote key that 'snapshot list' prints for a
+remote-only snapshot (an unambiguous leading part is enough).
+
 Requires the VAULTIK_AGE_SECRET_KEY environment variable to be set with
 the age private key.

@@ -14,18 +14,8 @@ var Module = fx.Module("log",
 )

 // New creates a new logger configuration from provided options.
-//
-// JSON is intentionally not carried into Config: a command emitting a
-// JSON document on stdout must keep its stderr log level under
-// --verbose/--debug, so --json must not lower it (issue #112). JSON
-// silences the stdout UI in setupGlobals instead.
 func New(opts Options) Config {
-	return Config{
-		Verbose: opts.Verbose,
-		Debug:   opts.Debug,
-		Cron:    opts.Cron,
-		Quiet:   opts.Quiet,
-	}
+	return Config(opts)
 }

 // Options are provided by the CLI.
@@ -34,8 +24,4 @@ type Options struct {
 	Debug   bool
 	Cron    bool
 	Quiet   bool
-	// JSON marks a command whose stdout carries a machine-readable
-	// document. It silences the human UI on stdout (see setupGlobals),
-	// but unlike Quiet it leaves the stderr log level alone.
-	JSON bool
 }
@@ -18,7 +18,6 @@ import (
 	"sneak.berlin/go/vaultik/internal/blobgen"
 	"sneak.berlin/go/vaultik/internal/database"
 	"sneak.berlin/go/vaultik/internal/log"
-	"sneak.berlin/go/vaultik/internal/snapshot"
 	"sneak.berlin/go/vaultik/internal/types"
 )

@@ -577,14 +576,20 @@ func (v *Vaultik) handleRestoreVerification(
 }

 // downloadSnapshotDB downloads and decrypts the snapshot metadata
-// database. The snapshotID is the human ID; we hash it to the remote
-// key for the storage path.
+// database. The identifier is resolved to the snapshot's remote key: a
+// human ID is hashed, and a remote key (or its abbreviation, as printed
+// for a remote-only snapshot) is used as-is, so a host with no local
+// index can restore the snapshots it can only see on the store.
 func (v *Vaultik) downloadSnapshotDB(
 	snapshotID string, identity age.Identity,
 ) (*database.DB, error) {
+	remoteKey, err := v.resolveSnapshotRemoteKey(snapshotID)
+	if err != nil {
+		return nil, err
+	}
+
 	// Download encrypted database from storage
-	dbKey := fmt.Sprintf("metadata/%s/db.zst.age",
-		snapshot.RemoteSnapshotKey(snapshotID))
+	dbKey := fmt.Sprintf("metadata/%s/db.zst.age", remoteKey)

 	reader, err := v.Storage.Get(v.ctx, dbKey)
 	if err != nil {
@@ -0,0 +1,167 @@
+package vaultik_test
+
+import (
+	"bytes"
+	"context"
+	"io"
+	"path/filepath"
+	"testing"
+
+	"github.com/spf13/afero"
+	"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/ui"
+	"sneak.berlin/go/vaultik/internal/vaultik"
+)
+
+// TestRestoreOnAnotherMachine proves the disaster-recovery path: a host
+// that has only the vaultik binary, the age secret key, and the storage
+// credentials — no local index, a different hostname, and no
+// age_recipients configured — can list, restore, and verify a snapshot
+// straight from the destination store.
+//
+// The backup half writes a snapshot with one index and hostname. The
+// restore half throws that index away entirely: a fresh, empty index and
+// a config that shares nothing with the original but the storage location
+// and the secret key. If restore or verify needed the original local
+// index — or the human snapshot ID that only that index holds — this test
+// could not run, because the recovery host can know neither.
+func TestRestoreOnAnotherMachine(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	fs := afero.NewOsFs()
+	tempDir := t.TempDir()
+
+	dataDir := filepath.Join(tempDir, "source")
+	storeDir := filepath.Join(tempDir, "remote")
+	restoreDir := filepath.Join(tempDir, "restored")
+	dbPath := filepath.Join(tempDir, "index.sqlite")
+
+	chunkSize := int64(64 * 1024)
+	maxBlobSize := int64(512 * 1024)
+
+	sourceFiles := writeRecoverySourceTree(t, fs, dataDir, chunkSize)
+
+	ctx := context.Background()
+
+	// Backup host: one index, hostname test-host, age_recipients set.
+	// runFileStorageBackup closes the index before returning, so nothing
+	// below can lean on it.
+	_, storer, originalID := runFileStorageBackup(
+		ctx, t, fs, dataDir, storeDir, dbPath, chunkSize, maxBlobSize)
+
+	// Recovery host: a fresh empty index, a different hostname, and no
+	// age_recipients — only the secret key and the same storage location.
+	recovery, stdout := newRecoveryHost(ctx, t, fs, storer)
+
+	// The recovery index really is empty. This is the assertion that makes
+	// the test a guard against restore quietly depending on the original
+	// index: if it did, an empty index would make restore fail.
+	localSnaps, err := recovery.Repositories.Snapshots.ListRecent(ctx, 100)
+	require.NoError(t, err)
+	require.Empty(t, localSnaps, "recovery host must start with no local index")
+
+	// List: the snapshot shows up as remote-only, identified by its remote
+	// key, with no recoverable human ID.
+	require.NoError(t, recovery.ListSnapshots(true))
+
+	rows := decodeListJSON(t, stdout.String())
+	require.Len(t, rows, 1)
+
+	remote := rows[0]
+	assert.False(t, remote.LocallyTracked, "snapshot must be remote-only here")
+	assert.Empty(t, remote.ID, "the human ID is unknown to the recovery host")
+	require.Len(t, remote.RemoteKey, 64)
+	assert.Equal(t, snapshot.RemoteSnapshotKey(originalID), remote.RemoteKey,
+		"the listed key is the hashed snapshot ID")
+
+	// Restore driven by the abbreviated identifier the table prints (the
+	// first 12 hex of the remote key), then deep-verify from the store
+	// keyed by the full remote key. Both are what a recovery host can know.
+	require.NoError(t, recovery.Restore(&vaultik.RestoreOptions{
+		SnapshotID: remote.RemoteKey[:12],
+		TargetDir:  restoreDir,
+		Verify:     true,
+	}))
+	require.NoError(t, recovery.RunDeepVerify(
+		remote.RemoteKey, &vaultik.VerifyOptions{Deep: true}))
+
+	assertRestoredTreeMatches(t, fs, restoreDir, sourceFiles)
+}
+
+// writeRecoverySourceTree writes a small source tree spanning several
+// chunks (so restore reassembles real multi-chunk files) and returns the
+// content keyed by absolute path.
+func writeRecoverySourceTree(
+	t *testing.T, fs afero.Fs, dataDir string, chunkSize int64,
+) map[string][]byte {
+	t.Helper()
+
+	sourceFiles := map[string][]byte{
+		filepath.Join(dataDir, "notes.txt"):        []byte("recover me"),
+		filepath.Join(dataDir, "sub", "big.bin"):   bytesPattern("big-", int(chunkSize*3)),
+		filepath.Join(dataDir, "sub", "small.bin"): bytesPattern("small-", 128),
+	}
+
+	for path, content := range sourceFiles {
+		require.NoError(t, fs.MkdirAll(filepath.Dir(path), 0o755))
+		require.NoError(t, afero.WriteFile(fs, path, content, 0o644))
+	}
+
+	return sourceFiles
+}
+
+// newRecoveryHost builds the Vaultik a replacement machine would run: an
+// empty in-memory index, a hostname different from the backup host, no
+// age_recipients, and only the secret key plus the shared storer. It
+// returns the instance and the buffer its stdout is wired to.
+func newRecoveryHost(
+	ctx context.Context, t *testing.T, fs afero.Fs, storer storage.Storer,
+) (*vaultik.Vaultik, *bytes.Buffer) {
+	t.Helper()
+
+	recoveryDB, err := database.New(ctx, ":memory:")
+	require.NoError(t, err)
+	t.Cleanup(func() { _ = recoveryDB.Close() })
+
+	stdout := &bytes.Buffer{}
+
+	recovery := &vaultik.Vaultik{
+		Config: &config.Config{
+			AgeSecretKey: testAgeSecretKey,
+			Hostname:     "recovery-host",
+		},
+		Storage:      storer,
+		Fs:           fs,
+		Repositories: database.NewRepositories(recoveryDB),
+		DB:           recoveryDB,
+		Stdout:       stdout,
+		Stderr:       io.Discard,
+		UI:           ui.NewWithColor(io.Discard, false),
+	}
+	recovery.SetContext(ctx)
+
+	return recovery, stdout
+}
+
+// assertRestoredTreeMatches byte-compares every restored file against its
+// source content.
+func assertRestoredTreeMatches(
+	t *testing.T, fs afero.Fs, restoreDir string, sourceFiles map[string][]byte,
+) {
+	t.Helper()
+
+	for origPath, expected := range sourceFiles {
+		restored := filepath.Join(restoreDir, origPath)
+		got, err := afero.ReadFile(fs, restored)
+		require.NoErrorf(t, err, "restored file missing: %s", restored)
+		require.Truef(t, bytes.Equal(got, expected),
+			"byte mismatch for %s", origPath)
+	}
+}
@@ -670,9 +670,11 @@ func (v *Vaultik) VerifySnapshotWithOptions(

 	v.printVerifyHeader(snapshotID, opts)

-	// Download and parse manifest. The caller supplies a human
-	// snapshot ID; we hash it to address remote storage.
-	manifest, err := v.downloadManifestByKey(snapshot.RemoteSnapshotKey(snapshotID))
+	// Resolve the identifier to the snapshot's remote key and download the
+	// manifest. A human ID is hashed; a remote key (or its abbreviation,
+	// as printed for a remote-only snapshot) is used as-is, so a host with
+	// no local index can verify a snapshot it can only see on the store.
+	manifest, err := v.resolveAndDownloadManifest(snapshotID)
 	if err != nil {
 		if opts.JSON {
 			result.Status = verifyStatusFailed
@@ -0,0 +1,101 @@
+package vaultik
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"sneak.berlin/go/vaultik/internal/snapshot"
+)
+
+// remoteKeyHexLen is the length of a full remote snapshot key: a SHA256
+// digest rendered as lowercase hex.
+const remoteKeyHexLen = 64
+
+// Sentinel errors for resolving a snapshot identifier against the store.
+var (
+	errSnapshotKeyNotFound = errors.New(
+		"no snapshot on the destination store matches this identifier")
+	errSnapshotKeyAmbiguous = errors.New(
+		"identifier matches more than one snapshot on the destination store")
+)
+
+// resolveSnapshotRemoteKey turns a snapshot identifier supplied on the
+// command line into the remote key that names the snapshot's metadata
+// directory on the destination store. Every remote path a restore or
+// verify reads is built from that key.
+//
+// Two forms are accepted, matching the two things a host can know:
+//
+//   - A human snapshot ID (hostname_name_timestamp), which a host holding
+//     the local index has. It is hashed to its remote key; the store is
+//     not consulted.
+//   - A remote key, or the leading part of one, which is all a host with
+//     no local index can know — it is exactly what `snapshot list` prints
+//     for a remote-only snapshot (see formatRemoteOnlyID). It is resolved
+//     against the destination store's metadata listing; an identifier that
+//     matches no snapshot, or more than one, is an error.
+//
+// The two are told apart by shape: a remote key is lowercase hex, and a
+// human snapshot ID never is (it carries a hostname, underscores, and an
+// RFC3339 timestamp).
+func (v *Vaultik) resolveSnapshotRemoteKey(identifier string) (string, error) {
+	if !isRemoteKeyOrPrefix(identifier) {
+		return snapshot.RemoteSnapshotKey(identifier), nil
+	}
+
+	keys, err := v.listAllRemoteSnapshotKeys()
+	if err != nil {
+		return "", fmt.Errorf(
+			"listing destination store to resolve %q: %w", identifier, err)
+	}
+
+	var matches []string
+
+	for _, key := range keys {
+		if strings.HasPrefix(key, identifier) {
+			matches = append(matches, key)
+		}
+	}
+
+	switch len(matches) {
+	case 1:
+		return matches[0], nil
+	case 0:
+		return "", fmt.Errorf("%w: %s", errSnapshotKeyNotFound, identifier)
+	default:
+		return "", fmt.Errorf("%w: %s (%d matches)",
+			errSnapshotKeyAmbiguous, identifier, len(matches))
+	}
+}
+
+// resolveAndDownloadManifest resolves a snapshot identifier to its remote
+// key (see resolveSnapshotRemoteKey) and downloads that snapshot's
+// manifest.
+func (v *Vaultik) resolveAndDownloadManifest(
+	identifier string,
+) (*snapshot.Manifest, error) {
+	remoteKey, err := v.resolveSnapshotRemoteKey(identifier)
+	if err != nil {
+		return nil, err
+	}
+
+	return v.downloadManifestByKey(remoteKey)
+}
+
+// isRemoteKeyOrPrefix reports whether s is a full remote key or the
+// leading part of one: 1 to 64 lowercase hex characters. A human snapshot
+// ID is never all hex, so this shape test is enough to tell the two apart.
+func isRemoteKeyOrPrefix(s string) bool {
+	if s == "" || len(s) > remoteKeyHexLen {
+		return false
+	}
+
+	for _, r := range s {
+		if (r < '0' || r > '9') && (r < 'a' || r > 'f') {
+			return false
+		}
+	}
+
+	return true
+}
@@ -138,8 +138,15 @@ func (v *Vaultik) RunDeepVerify(snapshotID string, opts *VerifyOptions) error {
 func (v *Vaultik) loadVerificationData(
 	snapshotID string, opts *VerifyOptions, result *VerifyResult,
 ) (*snapshot.Manifest, *tempDB, []snapshot.BlobInfo, error) {
-	// All remote paths use the hashed key derived from the human ID.
-	remoteKey := snapshot.RemoteSnapshotKey(snapshotID)
+	// Resolve the identifier to the snapshot's remote key. A human ID is
+	// hashed; a remote key (or its abbreviation, as printed for a
+	// remote-only snapshot) is used as-is, so a host with no local index
+	// can verify a snapshot it can only see on the store.
+	remoteKey, err := v.resolveSnapshotRemoteKey(snapshotID)
+	if err != nil {
+		return nil, nil, nil, v.deepVerifyFailure(result, opts,
+			fmt.Sprintf("resolving snapshot identifier: %v", err), err)
+	}

 	// Download manifest. downloadManifestByKey is the single reader for
 	// remote manifests; see its doc comment.
@@ -186,7 +193,7 @@ func (v *Vaultik) loadVerificationData(
 			fmt.Errorf("failed to decrypt database: %w", err))
 	}

-	dbBlobs, err := v.getBlobsFromDatabase(snapshotID, tdb.DB)
+	dbBlobs, err := v.getBlobsFromDatabase(tdb.DB)
 	if err != nil {
 		_ = tdb.Close()

@@ -501,19 +508,21 @@ func (v *Vaultik) verifyBlobFinalIntegrity(
 	return nil
 }

-// getBlobsFromDatabase gets all blobs for the snapshot from the database
-func (v *Vaultik) getBlobsFromDatabase(
-	snapshotID string, db *sql.DB,
-) ([]snapshot.BlobInfo, error) {
+// getBlobsFromDatabase gets all blobs for the snapshot from the database.
+//
+// The exported per-snapshot database holds exactly one snapshot's data
+// (see cleanSnapshotDB), so every row in snapshot_blobs belongs to it.
+// We select them directly rather than filtering by the human snapshot ID,
+// which a host restoring from the store alone does not have.
+func (v *Vaultik) getBlobsFromDatabase(db *sql.DB) ([]snapshot.BlobInfo, error) {
 	query := `
 		SELECT b.blob_hash, b.compressed_size
 		FROM snapshot_blobs sb
 		JOIN blobs b ON sb.blob_hash = b.blob_hash
-		WHERE sb.snapshot_id = ?
 		ORDER BY b.blob_hash
 	`

-	rows, err := db.QueryContext(v.ctx, query, snapshotID)
+	rows, err := db.QueryContext(v.ctx, query)
 	if err != nil {
 		return nil, fmt.Errorf("failed to query snapshot blobs: %w", err)
 	}