diff --git a/proto/backend.proto b/proto/backend.proto
index d8b12e3d7..6a505c37c 100644
--- a/proto/backend.proto
+++ b/proto/backend.proto
@@ -71,7 +71,7 @@ message BackendInput {
         int32 get_changed_notetypes = 56;
         AddOrUpdateNotetypeIn add_or_update_notetype = 57;
         Empty get_all_decks = 58;
-        bytes set_all_decks = 59;
+//        bytes set_all_decks = 59;
         Empty all_stock_notetypes = 60;
         int64 get_notetype_legacy = 61;
         Empty get_notetype_names = 62;
@@ -83,6 +83,12 @@ message BackendInput {
         Note update_note = 68;
         int64 get_note = 69;
         Empty get_empty_cards = 70;
+        int64 get_deck_legacy = 71;
+        string get_deck_id_by_name = 72;
+        Empty get_deck_names = 73;
+        AddOrUpdateDeckLegacyIn add_or_update_deck_legacy = 74;
+        bool new_deck_legacy = 75;
+        int64 remove_deck = 76;
     }
 }
 
@@ -134,7 +140,7 @@ message BackendOutput {
         bytes get_changed_notetypes = 56;
         int64 add_or_update_notetype = 57;
         bytes get_all_decks = 58;
-        Empty set_all_decks = 59;
+//        Empty set_all_decks = 59;
         bytes get_notetype_legacy = 61;
         NoteTypeNames get_notetype_names = 62;
         NoteTypeUseCounts get_notetype_names_and_counts = 63;
@@ -145,6 +151,12 @@ message BackendOutput {
         Empty update_note = 68;
         Note get_note = 69;
         EmptyCardsReport get_empty_cards = 70;
+        bytes get_deck_legacy = 71;
+        int64 get_deck_id_by_name = 72;
+        DeckNames get_deck_names = 73;
+        int64 add_or_update_deck_legacy = 74;
+        bytes new_deck_legacy = 75;
+        Empty remove_deck = 76;
 
         BackendError error = 2047;
     }
@@ -166,6 +178,8 @@ message BackendError {
         string json_error = 9;
         string proto_error = 10;
         Empty not_found_error = 11;
+        Empty exists = 12;
+        Empty deck_is_filtered = 13;
     }
 }
 
@@ -614,3 +628,80 @@ message NoteWithEmptyCards {
     repeated int64 card_ids = 2;
     bool will_delete_note = 3;
 }
+
+message Deck {
+    int64 id = 1;
+    string name = 2;
+    uint32 mtime_secs = 3;
+    int32 usn = 4;
+    DeckCommon common = 5;
+    oneof kind {
+        NormalDeck normal = 6;
+        FilteredDeck filtered = 7;
+    }
+}
+
+message DeckCommon {
+    bool collapsed = 1;
+    uint32 last_day_studied = 2;
+    int32 new_studied = 3;
+    int32 review_studied = 4;
+    int32 learning_studied = 5;
+    int32 secs_studied = 6;
+    bytes other = 16;
+}
+
+message DeckKind {
+    oneof kind {
+        NormalDeck normal = 1;
+        FilteredDeck filtered = 2;
+    }
+}
+
+message NormalDeck {
+    int64 config_id = 1;
+    uint32 extend_new = 2;
+    uint32 extend_review = 3;
+    string description = 4;
+}
+
+message FilteredDeck {
+    bool reschedule = 1;
+    repeated FilteredSearchTerm search_terms = 2;
+    // v1 scheduler only
+    repeated float delays = 3;
+    // v2 scheduler only
+    uint32 preview_delay = 4;
+}
+
+message FilteredSearchTerm {
+    string search = 1;
+    uint32 limit = 2;
+    FilteredSearchOrder order = 3;
+}
+
+enum FilteredSearchOrder {
+    FILTERED_SEARCH_ORDER_OLDEST_FIRST = 0;
+    FILTERED_SEARCH_ORDER_RANDOM = 1;
+    FILTERED_SEARCH_ORDER_INTERVALS_ASCENDING = 2;
+    FILTERED_SEARCH_ORDER_INTERVALS_DESCENDING = 3;
+    FILTERED_SEARCH_ORDER_LAPSES = 4;
+    FILTERED_SEARCH_ORDER_ADDED = 5;
+    FILTERED_SEARCH_ORDER_DUE = 6;
+    FILTERED_SEARCH_ORDER_REVERSE_ADDED = 7;
+    FILTERED_SEARCH_ORDER_DUE_PRIORITY = 8;
+}
+
+message DeckNames {
+    repeated DeckNameID entries = 1;
+}
+
+message DeckNameID {
+    int64 id = 1;
+    string name = 2;
+}
+
+message AddOrUpdateDeckLegacyIn {
+    bytes deck = 1;
+    bool preserve_usn_and_mtime = 2;
+}
diff --git a/pylib/anki/collection.py b/pylib/anki/collection.py
index 8afbd45a8..33ea1cc97 100644
--- a/pylib/anki/collection.py
+++ b/pylib/anki/collection.py
@@ -158,14 +158,10 @@ class _Collection:
             self.dty,  # no longer used
             self._usn,
             self.ls,
-            decks,
         ) = self.db.first(
             """
-select crt, mod, scm, dty, usn, ls,
-decks from col"""
+select crt, mod, scm, dty, usn, ls from col"""
         )
-        self.decks.decks = self.backend.get_all_decks()
-        self.decks.changed = False
 
     def setMod(self) -> None:
         """Mark DB modified.
diff --git a/pylib/anki/decks.py b/pylib/anki/decks.py
index 0ae47b9c9..d1c6ec379 100644
--- a/pylib/anki/decks.py
+++ b/pylib/anki/decks.py
@@ -8,6 +8,7 @@ import unicodedata
 from typing import Any, Dict, List, Optional, Set, Tuple, Union
 
 import anki  # pylint: disable=unused-import
+import anki.backend_pb2 as pb
 from anki import hooks
 from anki.consts import *
 from anki.errors import DeckRenameError
@@ -25,11 +26,13 @@ defaultDeck = {
     "conf": 1,
     "usn": 0,
     "desc": "",
-    "dyn": DECK_STD,  # anki uses int/bool interchangably here
+    "dyn": DECK_STD,
     "collapsed": False,
     # added in beta11
     "extendNew": 10,
     "extendRev": 50,
+    # fixme: if we keep this, mod must be set or handled in serde
+    "mod": 0,
 }
 
 defaultDynamicDeck = {
@@ -49,119 +52,140 @@ defaultDynamicDeck = {
     "return": True,  # currently unused
     # v2 scheduler
     "previewDelay": 10,
+    "mod": 0,
 }
 
 
-class DeckManager:
-    decks: Dict[str, Any]
+class DecksDictProxy:
+    def __init__(self, col: anki.storage._Collection):
+        self._col = col.weakref()
 
+    def _warn(self):
+        print("add-on should use methods on col.decks, not col.decks.decks dict")
+
+    def __getitem__(self, item):
+        self._warn()
+        return self._col.decks.get(int(item))
+
+    def __setitem__(self, key, val):
+        self._warn()
+        self._col.decks.save(val)
+
+    def __len__(self):
+        self._warn()
+        return len(self._col.decks.all_names_and_ids())
+
+    def keys(self):
+        self._warn()
+        return [str(nt.id) for nt in self._col.decks.all_names_and_ids()]
+
+    def values(self):
+        self._warn()
+        return self._col.decks.all()
+
+    def items(self):
+        self._warn()
+        return [(str(nt["id"]), nt) for nt in self._col.decks.all()]
+
+    def __contains__(self, item):
+        self._warn()
+        self._col.decks.have(item)
+
+
+class DeckManager:
     # Registry save/load
     #############################################################
 
     def __init__(self, col: anki.storage._Collection) -> None:
         self.col = col.weakref()
-        self.decks = {}
+        self.decks = DecksDictProxy(col)
+        # do not access this directly!
+        # self._cache: Dict[int, ] = {}
+        #        self.decks = {}
         self._dconf_cache: Optional[Dict[int, Dict[str, Any]]] = None
 
-    def save(self, g: Optional[Any] = None) -> None:
+    def save(self, g: Dict = None) -> None:
         "Can be called with either a deck or a deck configuration."
-        if g:
-            # deck conf?
-            if "maxTaken" in g:
-                self.update_config(g)
-                return
-            else:
-                g["mod"] = intTime()
-                g["usn"] = self.col.usn()
-        self.changed = True
+        if not g:
+            print("col.decks.save() should be passed the changed deck")
+            return
 
-    def flush(self) -> None:
-        if self.changed:
-            self.col.backend.set_all_decks(self.decks)
-            self.changed = False
+        # deck conf?
+        if "maxTaken" in g:
+            self.update_config(g)
+            return
+        else:
+            # g["mod"] = intTime()
+            # g["usn"] = self.col.usn()
+            self.update(g)
+
+    # legacy
+    def flush(self):
+        pass
 
     # Deck save/load
     #############################################################
 
+    # fixme: if we're stripping chars on add, then we need to do that on lookup as well
+    # and need to make sure \x1f conversion
+
     def id(
         self, name: str, create: bool = True, type: Optional[Dict[str, Any]] = None
     ) -> Optional[int]:
         "Add a deck with NAME. Reuse deck if already exists. Return id as int."
         if type is None:
             type = defaultDeck
-        name = name.replace('"', "")
-        name = unicodedata.normalize("NFC", name)
-        deck = self.byName(name)
-        if deck:
-            return int(deck["id"])
-        if not create:
-            return None
-        g = copy.deepcopy(type)
-        if "::" in name:
-            # not top level; ensure all parents exist
-            name = self._ensureParents(name)
-        g["name"] = name
-        while 1:
-            id = intTime(1000)
-            if str(id) not in self.decks:
-                break
-        g["id"] = id
-        self.decks[str(id)] = g
-        self.save(g)
-        self.maybeAddToActive()
-        hooks.deck_added(g)
-        return int(id)
 
-    def rem(self, did: int, cardsToo: bool = False, childrenToo: bool = True) -> None:
+        id = self.id_for_name(name)
+        if id:
+            return id
+        elif not create:
+            return None
+
+        deck = self.new_deck_legacy(bool(type["dyn"]))
+        deck["name"] = name
+        self.update(deck)
+
+        # fixme
+        self.maybeAddToActive()
+
+        # fixme
+        hooks.deck_added(deck)
+
+        return deck["id"]
+
+    def rem(self, did: int, cardsToo: bool = True, childrenToo: bool = True) -> None:
         "Remove the deck. If cardsToo, delete any cards inside."
-        if str(did) == "1":
-            # we won't allow the default deck to be deleted, but if it's a
-            # child of an existing deck then it needs to be renamed
-            deck = self.get(did)
-            if "::" in deck["name"]:
-                base = self.basename(deck["name"])
-                suffix = ""
-                while True:
-                    # find an unused name
-                    name = base + suffix
-                    if not self.byName(name):
-                        deck["name"] = name
-                        self.save(deck)
-                        break
-                    suffix += "1"
-            return
-        # log the removal regardless of whether we have the deck or not
-        self.col._logRem([did], REM_DECK)
-        # do nothing else if doesn't exist
-        if not str(did) in self.decks:
-            return
-        deck = self.get(did)
-        if deck["dyn"]:
-            # deleting a cramming deck returns cards to their previous deck
-            # rather than deleting the cards
-            self.col.sched.emptyDyn(did)
-            if childrenToo:
-                for name, id in self.children(did):
-                    self.rem(id, cardsToo, childrenToo=False)
-        else:
-            # delete children first
-            if childrenToo:
-                # we don't want to delete children when syncing
-                for name, id in self.children(did):
-                    self.rem(id, cardsToo, childrenToo=False)
-            # delete cards too?
-            if cardsToo:
-                # don't use cids(), as we want cards in cram decks too
-                cids = self.col.db.list(
-                    "select id from cards where did=? or odid=?", did, did
-                )
-                self.col.remCards(cids)
-        # delete the deck and add a grave
-        del self.decks[str(did)]
+        assert cardsToo and childrenToo
+        self.col.backend.remove_deck(did)
+        # fixme: default deck special case
+        # if str(did) == "1":
+        #     # we won't allow the default deck to be deleted, but if it's a
+        #     # child of an existing deck then it needs to be renamed
+        #     deck = self.get(did)
+        #     if "::" in deck["name"]:
+        #         base = self.basename(deck["name"])
+        #         suffix = ""
+        #         while True:
+        #             # find an unused name
+        #             name = base + suffix
+        #             if not self.byName(name):
+        #                 deck["name"] = name
+        #                 self.save(deck)
+        #                 break
+        #             suffix += "1"
+        #     return
+
+        # fixme:
+        #         # don't use cids(), as we want cards in cram decks too
+        #         cids = self.col.db.list(
+        #             "select id from cards where did=? or odid=?", did, did
+        #         )
+
+        # fixme
         # ensure we have an active deck
         if did in self.active():
-            self.select(int(list(self.decks.keys())[0]))
-        self.save()
+            self.select(self.all_names_and_ids()[0].id)
 
     def allNames(self, dyn: bool = True, force_default: bool = True) -> List:
         "An unsorted list of all deck names."
@@ -172,6 +196,29 @@ class DeckManager:
                 x["name"] for x in self.all(force_default=force_default) if not x["dyn"]
             ]
 
+    def all_names_and_ids(self) -> List[pb.DeckNameID]:
+        return self.col.backend.get_deck_names_and_ids()
+
+    def id_for_name(self, name: str) -> Optional[int]:
+        return self.col.backend.get_deck_id_by_name(name)
+
+    def get_legacy(self, did: int) -> Optional[Dict]:
+        return self.col.backend.get_deck_legacy(did)
+
+    def have(self, id: int) -> bool:
+        return not self.get_legacy(int(id))
+
+    def get_all_legacy(self) -> List[Dict]:
+        return list(self.col.backend.get_all_decks().values())
+
+    def new_deck_legacy(self, filtered: bool) -> Dict:
+        try:
+            return self.col.backend.new_deck_legacy(filtered)
+        except anki.rsbackend.DeckIsFilteredError:
+            raise DeckRenameError("deck was filtered")
+        except anki.rsbackend.ExistsError:
+            raise DeckRenameError("deck already exists")
+
     def all(self, force_default: bool = True) -> List:
         """A list of all decks.
 
@@ -181,19 +228,20 @@ class DeckManager:
         * default deck contains a card
         * default deck has a child (assumed not to be the case if assume_no_child)
         """
-        decks = list(self.decks.values())
+        decks = self.get_all_legacy()
         if not force_default and not self.should_default_be_displayed(force_default):
             decks = [deck for deck in decks if deck["id"] != 1]
         return decks
 
     def allIds(self) -> List[str]:
-        return list(self.decks.keys())
+        return [str(x.id) for x in self.all_names_and_ids()]
 
     def collapse(self, did) -> None:
         deck = self.get(did)
         deck["collapsed"] = not deck["collapsed"]
         self.save(deck)
 
+    # fixme
     def collapseBrowser(self, did) -> None:
         deck = self.get(did)
         collapsed = deck.get("browserCollapsed", False)
@@ -201,51 +249,54 @@ class DeckManager:
         self.save(deck)
 
     def count(self) -> int:
-        return len(self.decks)
+        return len(self.all_names_and_ids())
 
-    def get(self, did: Union[int, str], default: bool = True) -> Any:
-        id = str(did)
-        if id in self.decks:
-            return self.decks[id]
+    def get(self, did: Union[int, str], default: bool = True) -> Optional[Dict]:
+        if not did:
+            if default:
+                return self.get_legacy(1)
+            else:
+                return None
+        id = int(did)
+        deck = self.get_legacy(id)
+        if deck:
+            return deck
         elif default:
-            return self.decks["1"]
+            return self.get_legacy(1)
+        else:
+            return None
 
-    def byName(self, name: str) -> Any:
+    def byName(self, name: str) -> Optional[Dict]:
         """Get deck with NAME, ignoring case."""
-        for m in list(self.decks.values()):
-            if self.equalName(m["name"], name):
-                return m
+        id = self.id_for_name(name)
+        if id:
+            return self.get_legacy(id)
+        return None
 
-    def update(self, g: Dict[str, Any]) -> None:
+    def update(self, g: Dict[str, Any], preserve_usn=False) -> None:
         "Add or update an existing deck. Used for syncing and merging."
-        self.decks[str(g["id"])] = g
+        try:
+            self.col.backend.add_or_update_deck_legacy(g, preserve_usn)
+        except anki.rsbackend.DeckIsFilteredError:
+            raise DeckRenameError("deck was filtered")
+        except anki.rsbackend.ExistsError:
+            raise DeckRenameError("deck already exists")
+
+        #       self.decks[str(g["id"])] = g
         self.maybeAddToActive()
         # mark registry changed, but don't bump mod time
-        self.save()
+
+    #        self.save()
 
     def rename(self, g: Dict[str, Any], newName: str) -> None:
         "Rename deck prefix to NAME if not exists. Updates children."
-        # make sure target node doesn't already exist
-        if self.byName(newName):
-            raise DeckRenameError(_("That deck already exists."))
-        # make sure we're not nesting under a filtered deck
-        for p in self.parentsByName(newName):
-            if p["dyn"]:
-                raise DeckRenameError(_("A filtered deck cannot have subdecks."))
-        # ensure we have parents
-        newName = self._ensureParents(newName)
-        # rename children
-        for grp in self.all():
-            if grp["name"].startswith(g["name"] + "::"):
-                grp["name"] = grp["name"].replace(g["name"] + "::", newName + "::", 1)
-                self.save(grp)
-        # adjust name
         g["name"] = newName
-        # ensure we have parents again, as we may have renamed parent->child
-        newName = self._ensureParents(newName)
-        self.save(g)
-        # renaming may have altered active did order
-        self.maybeAddToActive()
+        self.update(g)
+        return
+
+        # fixme: ensure rename of b in a::b::c generates new b
+        # fixme: renaming may have altered active did order
+        # self.maybeAddToActive()
 
     def renameForDragAndDrop(self, draggedDeckDid: int, ontoDeckDid: Any) -> None:
         draggedDeck = self.get(draggedDeckDid)
@@ -389,6 +440,7 @@ class DeckManager:
         grp["conf"] = id
         self.save(grp)
 
+    # fixme: expensive
     def didsForConf(self, conf) -> List:
         dids = []
         for deck in list(self.decks.values()):
@@ -459,16 +511,18 @@ class DeckManager:
     def for_card_ids(self, cids: List[int]) -> List[int]:
         return self.col.db.list(f"select did from cards where id in {ids2str(cids)}")
 
+    # fixme
     def _recoverOrphans(self) -> None:
-        dids = list(self.decks.keys())
-        mod = self.col.db.mod
-        self.col.db.execute(
-            "update cards set did = 1 where did not in " + ids2str(dids)
-        )
-        self.col.db.mod = mod
+        pass
+        # dids = list(self.decks.keys())
+        # mod = self.col.db.mod
+        # self.col.db.execute(
+        #     "update cards set did = 1 where did not in " + ids2str(dids)
+        # )
+        # self.col.db.mod = mod
 
     def _checkDeckTree(self) -> None:
-        decks = self.col.decks.all()
+        decks = self.all()
         decks.sort(key=self.key)
         names: Set[str] = set()
 
@@ -522,18 +576,20 @@ class DeckManager:
             return True
         if self.col.db.scalar("select 1 from cards where did = 1 limit 1"):
             return True
-        if len(self.decks) == 1:
-            return True
-        # looking for children
-        if assume_no_child:
-            return False
-        if default_deck is None:
-            default_deck = self.get(1)
-        defaultName = default_deck["name"]
-        for name in self.allNames():
-            if name.startswith(f"{defaultName}::"):
-                return True
+        # fixme
         return False
+        # if len(self.all_names_and_ids()) == 1:
+        #     return True
+        # # looking for children
+        # if assume_no_child:
+        #     return False
+        # if default_deck is None:
+        #     default_deck = self.get(1)
+        # defaultName = default_deck["name"]
+        # for name in self.allNames():
+        #     if name.startswith(f"{defaultName}::"):
+        #         return True
+        # return False
 
     # Deck selection
     #############################################################
@@ -632,7 +688,7 @@ class DeckManager:
         return parents
 
     def nameMap(self) -> dict:
-        return dict((d["name"], d) for d in self.decks.values())
+        return dict((d["name"], d) for d in self.all())
 
     # Sync handling
     ##########################################################################
diff --git a/pylib/anki/models.py b/pylib/anki/models.py
index 6a1de1d6d..9dfab2eb1 100644
--- a/pylib/anki/models.py
+++ b/pylib/anki/models.py
@@ -191,9 +191,6 @@ class ModelManager:
     def all_use_counts(self) -> List[pb.NoteTypeNameIDUseCount]:
         return self.col.backend.get_notetype_use_counts()
 
-    def id_for_name(self, name: str) -> Optional[int]:
-        return self.col.backend.get_notetype_id_by_name(name)
-
     # legacy
 
     def allNames(self) -> List[str]:
@@ -227,6 +224,9 @@ class ModelManager:
     # Retrieving and creating models
     #############################################################
 
+    def id_for_name(self, name: str) -> Optional[int]:
+        return self.col.backend.get_notetype_id_by_name(name)
+
     def get(self, id: int) -> Optional[NoteType]:
         "Get model with ID, or None."
         # deal with various legacy input types
diff --git a/pylib/anki/rsbackend.py b/pylib/anki/rsbackend.py
index 34e7cb957..7edf4fe97 100644
--- a/pylib/anki/rsbackend.py
+++ b/pylib/anki/rsbackend.py
@@ -102,6 +102,14 @@ class NotFoundError(Exception):
     pass
 
 
+class ExistsError(Exception):
+    pass
+
+
+class DeckIsFilteredError(Exception):
+    pass
+
+
 def proto_exception_to_native(err: pb.BackendError) -> Exception:
     val = err.WhichOneof("value")
     if val == "interrupted":
@@ -122,6 +130,10 @@ def proto_exception_to_native(err: pb.BackendError) -> Exception:
         return StringError(err.localized)
     elif val == "not_found_error":
         return NotFoundError()
+    elif val == "exists":
+        return ExistsError()
+    elif val == "deck_is_filtered":
+        return DeckIsFilteredError()
     else:
         assert_impossible_literal(val)
 
@@ -597,9 +609,6 @@ class RustBackend:
         ).get_all_decks
         return orjson.loads(jstr)
 
-    def set_all_decks(self, nts: Dict[str, Dict[str, Any]]):
-        self._run_command(pb.BackendInput(set_all_decks=orjson.dumps(nts)))
-
     def all_stock_notetypes(self) -> List[NoteType]:
         return list(
             self._run_command(
@@ -674,6 +683,52 @@ class RustBackend:
             pb.BackendInput(get_empty_cards=pb.Empty()), release_gil=True
         ).get_empty_cards
 
+    def get_deck_legacy(self, did: int) -> Optional[Dict]:
+        try:
+            bytes = self._run_command(
+                pb.BackendInput(get_deck_legacy=did)
+            ).get_deck_legacy
+            return orjson.loads(bytes)
+        except NotFoundError:
+            return None
+
+    def get_deck_names_and_ids(self) -> List[pb.DeckNameID]:
+        return list(
+            self._run_command(
+                pb.BackendInput(get_deck_names=pb.Empty())
+            ).get_deck_names.entries
+        )
+
+    def add_or_update_deck_legacy(
+        self, deck: Dict[str, Any], preserve_usn: bool
+    ) -> None:
+        deck_json = orjson.dumps(deck)
+        id = self._run_command(
+            pb.BackendInput(
+                add_or_update_deck_legacy=pb.AddOrUpdateDeckLegacyIn(
+                    deck=deck_json, preserve_usn_and_mtime=preserve_usn
+                )
+            )
+        ).add_or_update_deck_legacy
+        deck["id"] = id
+
+    def new_deck_legacy(self, filtered: bool) -> Dict[str, Any]:
+        jstr = self._run_command(
+            pb.BackendInput(new_deck_legacy=filtered)
+        ).new_deck_legacy
+        return orjson.loads(jstr)
+
+    def get_deck_id_by_name(self, name: str) -> Optional[int]:
+        return (
+            self._run_command(
+                pb.BackendInput(get_deck_id_by_name=name)
+            ).get_deck_id_by_name
+            or None
+        )
+
+    def remove_deck(self, did: int) -> None:
+        self._run_command(pb.BackendInput(remove_deck=did))
+
 
 def translate_string_in(
     key: TR, **kwargs: Union[str, int, float]
diff --git a/pylib/anki/storage.py b/pylib/anki/storage.py
index 82da0dc0c..daa697f9c 100644
--- a/pylib/anki/storage.py
+++ b/pylib/anki/storage.py
@@ -1,8 +1,6 @@
 # Copyright: Ankitects Pty Ltd and contributors
 # License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
-import copy
-import json
 import os
 import weakref
 from dataclasses import dataclass
@@ -10,10 +8,8 @@ from typing import Optional
 
 from anki.collection import _Collection
 from anki.dbproxy import DBProxy
-from anki.lang import _
 from anki.media import media_paths_from_col_path
 from anki.rsbackend import RustBackend
-from anki.utils import intTime
 
 
 @dataclass
@@ -43,37 +39,7 @@ def Collection(
     backend.open_collection(path, media_dir, media_db, log_path)
     db = DBProxy(weakref.proxy(backend), path)
 
-    # initial setup required?
-    create = db.scalar("select decks = '{}' from col")
-    if create:
-        initial_db_setup(db)
-
     # add db to col and do any remaining upgrades
-    col = _Collection(db, backend=backend, server=server, log=should_log)
-    if create:
-        col.save()
-    else:
-        db.begin()
-    return col
-
-
-# Creating a new collection
-######################################################################
-
-
-def initial_db_setup(db: DBProxy) -> None:
-    import anki.decks
-
+    col = _Collection(db, backend=backend, server=server)
     db.begin()
-
-    g = copy.deepcopy(anki.decks.defaultDeck)
-    g["id"] = 1
-    g["name"] = _("Default")
-    g["conf"] = 1
-    g["mod"] = intTime()
-
-    db.execute(
-        """
-update col set decks = ?""",
-        json.dumps({"1": g}),
-    )
+    return col
diff --git a/pylib/tests/test_decks.py b/pylib/tests/test_decks.py
index b53510d27..69a465305 100644
--- a/pylib/tests/test_decks.py
+++ b/pylib/tests/test_decks.py
@@ -7,13 +7,13 @@ from tests.shared import assertException, getEmptyCol
 def test_basic():
     deck = getEmptyCol()
     # we start with a standard deck
-    assert len(deck.decks.decks) == 1
+    assert len(deck.decks.all_names_and_ids()) == 1
     # it should have an id of 1
     assert deck.decks.name(1)
     # create a new deck
     parentId = deck.decks.id("new deck")
     assert parentId
-    assert len(deck.decks.decks) == 2
+    assert len(deck.decks.all_names_and_ids()) == 2
     # should get the same id
     assert deck.decks.id("new deck") == parentId
     # we start with the default deck selected
@@ -54,22 +54,11 @@ def test_remove():
     deck.addNote(f)
     c = f.cards()[0]
     assert c.did == g1
-    # by default deleting the deck leaves the cards with an invalid did
     assert deck.cardCount() == 1
     deck.decks.rem(g1)
-    assert deck.cardCount() == 1
-    c.load()
-    assert c.did == g1
-    # but if we try to get it, we get the default
-    assert deck.decks.name(c.did) == "[no deck]"
-    # let's create another deck and explicitly set the card to it
-    g2 = deck.decks.id("g2")
-    c.did = g2
-    c.flush()
-    # this time we'll delete the card/note too
-    deck.decks.rem(g2, cardsToo=True)
     assert deck.cardCount() == 0
-    assert deck.noteCount() == 0
+    # if we try to get it, we get the default
+    assert deck.decks.name(c.did) == "[no deck]"
 
 
 def test_rename():
diff --git a/pylib/tests/test_schedv1.py b/pylib/tests/test_schedv1.py
index c323f0912..6afdbcccf 100644
--- a/pylib/tests/test_schedv1.py
+++ b/pylib/tests/test_schedv1.py
@@ -630,6 +630,7 @@ def test_cram():
     assert d.sched.nextIvl(c, 2) == 138 * 60 * 60 * 24
     cram = d.decks.get(did)
     cram["delays"] = [1, 10]
+    d.decks.save(cram)
     assert d.sched.answerButtons(c) == 3
     assert d.sched.nextIvl(c, 1) == 60
     assert d.sched.nextIvl(c, 2) == 600
@@ -739,6 +740,7 @@ def test_cram_resched():
     did = d.decks.newDyn("Cram")
     cram = d.decks.get(did)
     cram["resched"] = False
+    d.decks.save(cram)
     d.sched.rebuildDyn(did)
     d.reset()
     # graduate should return it to new
@@ -1017,7 +1019,7 @@ def test_deckDue():
     foobaz = f.model()["did"] = d.decks.id("foo::baz")
     d.addNote(f)
     d.reset()
-    assert len(d.decks.decks) == 5
+    assert len(d.decks.all_names_and_ids()) == 5
     cnts = d.sched.deckDueList()
     assert cnts[0] == ["Default", 1, 0, 0, 1]
     assert cnts[1] == ["Default::1", default1, 1, 0, 0]
diff --git a/pylib/tests/test_schedv2.py b/pylib/tests/test_schedv2.py
index 4e1d822d3..a2e7202e8 100644
--- a/pylib/tests/test_schedv2.py
+++ b/pylib/tests/test_schedv2.py
@@ -460,6 +460,8 @@ def test_review_limits():
     assert tree[1][5][0][2] == 4  # child
 
     # switch limits
+    parent = d.decks.get(parent["id"])
+    child = d.decks.get(child["id"])
     d.decks.setConf(parent, cconf["id"])
     d.decks.setConf(child, pconf["id"])
     d.decks.select(parent["id"])
@@ -825,6 +827,7 @@ def test_preview():
     did = d.decks.newDyn("Cram")
     cram = d.decks.get(did)
     cram["resched"] = False
+    d.decks.save(cram)
     d.sched.rebuildDyn(did)
     d.reset()
     # grab the first card
@@ -1032,7 +1035,7 @@ def test_deckDue():
     foobaz = f.model()["did"] = d.decks.id("foo::baz")
     d.addNote(f)
     d.reset()
-    assert len(d.decks.decks) == 5
+    assert len(d.decks.all_names_and_ids()) == 5
     cnts = d.sched.deckDueList()
     assert cnts[0] == ["Default", 1, 1, 0, 1]
     assert cnts[1] == ["Default::1", default1, 1, 0, 0]
diff --git a/rslib/src/backend/mod.rs b/rslib/src/backend/mod.rs
index 1d862c3da..32e12a64e 100644
--- a/rslib/src/backend/mod.rs
+++ b/rslib/src/backend/mod.rs
@@ -11,7 +11,7 @@ use crate::{
     collection::{open_collection, Collection},
     config::SortKind,
     deckconf::{DeckConf, DeckConfID},
-    decks::{Deck, DeckID},
+    decks::{Deck, DeckID, DeckSchema11},
     err::{AnkiError, NetworkErrorKind, Result, SyncErrorKind},
     i18n::{tr_args, I18n, TR},
     latex::{extract_latex, extract_latex_expanding_clozes, ExtractedLatex},
@@ -78,6 +78,8 @@ fn anki_error_to_proto_error(err: AnkiError, i18n: &I18n) -> pb::BackendError {
         AnkiError::JSONError { info } => V::JsonError(info),
         AnkiError::ProtoError { info } => V::ProtoError(info),
         AnkiError::NotFound => V::NotFoundError(Empty {}),
+        AnkiError::Existing => V::Exists(Empty {}),
+        AnkiError::DeckIsFiltered => V::DeckIsFiltered(Empty {}),
     };
 
     pb::BackendError {
@@ -306,10 +308,6 @@ impl Backend {
                 OValue::GetChangedNotetypes(self.get_changed_notetypes()?)
             }
             Value::GetAllDecks(_) => OValue::GetAllDecks(self.get_all_decks()?),
-            Value::SetAllDecks(bytes) => {
-                self.set_all_decks(&bytes)?;
-                OValue::SetAllDecks(pb::Empty {})
-            }
             Value::AllStockNotetypes(_) => OValue::AllStockNotetypes(pb::AllStockNotetypesOut {
                 notetypes: all_stock_notetypes(&self.i18n)
                     .into_iter()
@@ -342,6 +340,22 @@ impl Backend {
             }
             Value::GetNote(nid) => OValue::GetNote(self.get_note(nid)?),
             Value::GetEmptyCards(_) => OValue::GetEmptyCards(self.get_empty_cards()?),
+            Value::GetDeckLegacy(did) => OValue::GetDeckLegacy(self.get_deck_legacy(did)?),
+            Value::GetDeckIdByName(name) => {
+                OValue::GetDeckIdByName(self.get_deck_id_by_name(&name)?)
+            }
+            Value::GetDeckNames(_) => OValue::GetDeckNames(self.get_deck_names()?),
+            Value::AddOrUpdateDeckLegacy(input) => {
+                OValue::AddOrUpdateDeckLegacy(self.add_or_update_deck_legacy(input)?)
+            }
+            Value::NewDeckLegacy(filtered) => {
+                OValue::NewDeckLegacy(self.new_deck_legacy(filtered)?)
+            }
+
+            Value::RemoveDeck(did) => OValue::RemoveDeck({
+                self.remove_deck(did)?;
+                pb::Empty {}
+            }),
         })
     }
 
@@ -846,14 +860,9 @@ impl Backend {
         // })
     }
 
-    fn set_all_decks(&self, json: &[u8]) -> Result<()> {
-        let val: HashMap<DeckID, Deck> = serde_json::from_slice(json)?;
-        self.with_col(|col| col.transact(None, |col| col.storage.set_all_decks(val)))
-    }
-
     fn get_all_decks(&self) -> Result<Vec<u8>> {
         self.with_col(|col| {
-            let decks = col.storage.get_all_decks()?;
+            let decks = col.storage.get_all_decks_as_schema11()?;
             serde_json::to_vec(&decks).map_err(Into::into)
         })
     }
@@ -974,6 +983,59 @@ impl Backend {
             })
         })
     }
+
+    fn get_deck_legacy(&self, did: i64) -> Result<Vec<u8>> {
+        self.with_col(|col| {
+            let deck: DeckSchema11 = col
+                .storage
+                .get_deck(DeckID(did))?
+                .ok_or(AnkiError::NotFound)?
+                .into();
+            serde_json::to_vec(&deck).map_err(Into::into)
+        })
+    }
+
+    fn get_deck_id_by_name(&self, human_name: &str) -> Result<i64> {
+        self.with_col(|col| {
+            col.get_deck_id(human_name)
+                .map(|d| d.map(|d| d.0).unwrap_or_default())
+        })
+    }
+
+    fn get_deck_names(&self) -> Result<pb::DeckNames> {
+        self.with_col(|col| {
+            let names = col.storage.get_all_deck_names()?;
+            Ok(pb::DeckNames {
+                entries: names
+                    .into_iter()
+                    .map(|(id, name)| pb::DeckNameId { id: id.0, name })
+                    .collect(),
+            })
+        })
+    }
+
+    fn add_or_update_deck_legacy(&self, input: pb::AddOrUpdateDeckLegacyIn) -> Result<i64> {
+        self.with_col(|col| {
+            let schema11: DeckSchema11 = serde_json::from_slice(&input.deck)?;
+            let mut deck: Deck = schema11.into();
+            col.add_or_update_deck(&mut deck, input.preserve_usn_and_mtime)?;
+            Ok(deck.id.0)
+        })
+    }
+
+    fn new_deck_legacy(&self, filtered: bool) -> Result<Vec<u8>> {
+        let deck = if filtered {
+            Deck::new_filtered()
+        } else {
+            Deck::new_normal()
+        };
+        let schema11: DeckSchema11 = deck.into();
+        serde_json::to_vec(&schema11).map_err(Into::into)
+    }
+
+    fn remove_deck(&self, did: i64) -> Result<()> {
+        self.with_col(|col| col.remove_deck_and_child_decks(DeckID(did)))
+    }
 }
 
 fn translate_arg_to_fluent_val(arg: &pb::TranslateArgValue) -> FluentValue {
diff --git a/rslib/src/card.rs b/rslib/src/card.rs
index b4a8fa99d..65b3d5b16 100644
--- a/rslib/src/card.rs
+++ b/rslib/src/card.rs
@@ -5,9 +5,13 @@ use crate::decks::DeckID;
 use crate::define_newtype;
 use crate::err::{AnkiError, Result};
 use crate::notes::NoteID;
-use crate::{collection::Collection, timestamp::TimestampSecs, types::Usn, undo::Undoable};
+use crate::{
+    collection::Collection, config::SchedulerVersion, timestamp::TimestampSecs, types::Usn,
+    undo::Undoable,
+};
 use num_enum::TryFromPrimitive;
 use serde_repr::{Deserialize_repr, Serialize_repr};
+use std::collections::HashSet;
 
 define_newtype!(CardID, i64);
 
@@ -86,6 +90,60 @@ impl Default for Card {
     }
 }
 
+impl Card {
+    pub(crate) fn return_home(&mut self, sched: SchedulerVersion) {
+        if self.odid.0 == 0 {
+            // this should not happen
+            return;
+        }
+
+        // fixme: avoid bumping mtime?
+        self.did = self.odid;
+        self.odid.0 = 0;
+        if self.odue > 0 {
+            self.due = self.odue;
+        }
+        self.odue = 0;
+
+        self.queue = match sched {
+            SchedulerVersion::V1 => {
+                match self.ctype {
+                    CardType::New => CardQueue::New,
+                    CardType::Learn => CardQueue::New,
+                    CardType::Review => CardQueue::Review,
+                    // not applicable in v1, should not happen
+                    CardType::Relearn => {
+                        println!("did not expect relearn type in v1 for card {}", self.id);
+                        CardQueue::New
+                    }
+                }
+            }
+            SchedulerVersion::V2 => {
+                if (self.queue as i8) >= 0 {
+                    match self.ctype {
+                        CardType::Learn | CardType::Relearn => {
+                            if self.due > 1_000_000_000 {
+                                // unix timestamp
+                                CardQueue::Learn
+                            } else {
+                                // day number
+                                CardQueue::DayLearn
+                            }
+                        }
+                        CardType::New => CardQueue::New,
+                        CardType::Review => CardQueue::Review,
+                    }
+                } else {
+                    self.queue
+                }
+            }
+        };
+
+        if sched == SchedulerVersion::V1 && self.ctype == CardType::Learn {
+            self.ctype = CardType::New;
+        }
+    }
+}
 #[derive(Debug)]
 pub(crate) struct UpdateCardUndo(Card);
 
@@ -145,6 +203,28 @@ impl Collection {
         card.usn = self.usn()?;
         self.storage.add_card(card)
     }
+
+    /// Remove cards and any resulting orphaned notes.
+    /// Expects a transaction.
+    pub(crate) fn remove_cards_inner(&mut self, cids: &[CardID]) -> Result<()> {
+        let usn = self.usn()?;
+        let mut nids = HashSet::new();
+        for cid in cids {
+            if let Some(card) = self.storage.get_card(*cid)? {
+                // fixme: undo
+                nids.insert(card.nid);
+                self.storage.remove_card(*cid)?;
+                self.storage.add_card_grave(*cid, usn)?;
+            }
+        }
+        for nid in nids {
+            if self.storage.note_is_orphaned(nid)? {
+                self.remove_note_only(nid, usn)?;
+            }
+        }
+
+        Ok(())
+    }
 }
 
 #[cfg(test)]
diff --git a/rslib/src/config.rs b/rslib/src/config.rs
index e1474e3ce..ebaa08f32 100644
--- a/rslib/src/config.rs
+++ b/rslib/src/config.rs
@@ -9,6 +9,7 @@ use serde::{de::DeserializeOwned, Serialize};
 use serde_aux::field_attributes::deserialize_bool_from_anything;
 use serde_derive::Deserialize;
 use serde_json::json;
+use serde_repr::{Deserialize_repr, Serialize_repr};
 use slog::warn;
 
 pub(crate) fn schema11_config_as_string() -> String {
@@ -40,6 +41,13 @@ pub(crate) enum ConfigKey {
     LocalOffset,
     CurrentNoteTypeID,
     NextNewCardPosition,
+    SchedulerVersion,
+}
+#[derive(PartialEq, Serialize_repr, Deserialize_repr, Clone, Copy)]
+#[repr(u8)]
+pub(crate) enum SchedulerVersion {
+    V1 = 1,
+    V2 = 2,
 }
 
 impl From<ConfigKey> for &'static str {
@@ -53,6 +61,7 @@ impl From<ConfigKey> for &'static str {
             ConfigKey::LocalOffset => "localOffset",
             ConfigKey::CurrentNoteTypeID => "curModel",
             ConfigKey::NextNewCardPosition => "nextPos",
+            ConfigKey::SchedulerVersion => "schedVer",
         }
     }
 }
@@ -142,6 +151,11 @@ impl Collection {
         self.set_config(ConfigKey::NextNewCardPosition, &pos.wrapping_add(1))?;
         Ok(pos)
     }
+
+    pub(crate) fn sched_ver(&self) -> SchedulerVersion {
+        self.get_config_optional(ConfigKey::SchedulerVersion)
+            .unwrap_or(SchedulerVersion::V1)
+    }
 }
 
 #[derive(Deserialize, PartialEq, Debug)]
diff --git a/rslib/src/decks/mod.rs b/rslib/src/decks/mod.rs
index c0fe58831..03d447c5c 100644
--- a/rslib/src/decks/mod.rs
+++ b/rslib/src/decks/mod.rs
@@ -1,15 +1,41 @@
 // Copyright: Ankitects Pty Ltd and contributors
 // License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
-use crate::{collection::Collection, define_newtype, err::Result};
-
+use crate::backend_proto as pb;
+pub use crate::backend_proto::{
+    deck_kind::Kind as DeckKind, Deck as DeckProto, DeckCommon, DeckKind as DeckKindProto,
+    FilteredDeck, FilteredSearchOrder, FilteredSearchTerm, NormalDeck,
+};
+use crate::{
+    card::CardID,
+    collection::Collection,
+    define_newtype,
+    err::{AnkiError, Result},
+    text::normalize_to_nfc,
+    timestamp::TimestampSecs,
+    types::Usn,
+};
 mod schema11;
-pub use schema11::Deck;
-use std::sync::Arc;
+pub use schema11::DeckSchema11;
+use std::{borrow::Cow, sync::Arc};
 
 define_newtype!(DeckID, i64);
 
-pub(crate) fn child_ids<'a>(decks: &'a [Deck], name: &str) -> impl Iterator<Item = DeckID> + 'a {
+#[derive(Debug)]
+pub struct Deck {
+    pub id: DeckID,
+    pub name: String,
+    pub mtime_secs: TimestampSecs,
+    pub usn: Usn,
+    pub common: DeckCommon,
+    pub kind: DeckKind,
+}
+
+// fixme: needs update
+pub(crate) fn child_ids<'a>(
+    decks: &'a [DeckSchema11],
+    name: &str,
+) -> impl Iterator<Item = DeckID> + 'a {
     let prefix = format!("{}::", name.to_ascii_lowercase());
     decks
         .iter()
@@ -17,7 +43,8 @@ pub(crate) fn child_ids<'a>(decks: &'a [Deck], name: &str) -> impl Iterator<Item
         .map(|d| d.id())
 }
 
-pub(crate) fn get_deck(decks: &[Deck], id: DeckID) -> Option<&Deck> {
+// fixme: needs update
+pub(crate) fn get_deck(decks: &[DeckSchema11], id: DeckID) -> Option<&DeckSchema11> {
     for d in decks {
         if d.id() == id {
             return Some(d);
@@ -28,12 +55,93 @@ pub(crate) fn get_deck(decks: &[Deck], id: DeckID) -> Option<&Deck> {
 }
 
 impl Deck {
-    pub(crate) fn is_filtered(&self) -> bool {
-        matches!(self, Deck::Filtered(_))
+    pub fn new_normal() -> Deck {
+        let mut norm = NormalDeck::default();
+        norm.config_id = 1;
+
+        Deck {
+            id: DeckID(0),
+            name: "".into(),
+            mtime_secs: TimestampSecs(0),
+            usn: Usn(0),
+            common: DeckCommon::default(),
+            kind: DeckKind::Normal(norm),
+        }
+    }
+
+    pub fn new_filtered() -> Deck {
+        let mut filt = FilteredDeck::default();
+        filt.search_terms.push(FilteredSearchTerm {
+            search: "".into(),
+            limit: 100,
+            order: 0,
+        });
+        filt.preview_delay = 10;
+        filt.reschedule = true;
+        Deck {
+            id: DeckID(0),
+            name: "".into(),
+            mtime_secs: TimestampSecs(0),
+            usn: Usn(0),
+            common: DeckCommon::default(),
+            kind: DeckKind::Filtered(filt),
+        }
     }
 }
 
+impl Deck {
+    pub(crate) fn is_filtered(&self) -> bool {
+        matches!(self.kind, DeckKind::Filtered(_))
+    }
+
+    pub(crate) fn prepare_for_update(&mut self) {
+        // fixme - we currently only do this when converting from human; should be done in pub methods instead
+
+        // if self.name.contains(invalid_char_for_deck_component) {
+        //     self.name = self.name.replace(invalid_char_for_deck_component, "");
+        // }
+        // ensure_string_in_nfc(&mut self.name);
+    }
+
+    // fixme: unify with prepare for update
+    pub(crate) fn set_modified(&mut self, usn: Usn) {
+        self.mtime_secs = TimestampSecs::now();
+        self.usn = usn;
+    }
+}
+
+// fixme: need to bump usn on upgrade if we rename
+fn invalid_char_for_deck_component(c: char) -> bool {
+    c.is_ascii_control() || c == '"'
+}
+
+fn normalized_deck_name_component(comp: &str) -> Cow<str> {
+    let mut out = normalize_to_nfc(comp);
+    if out.contains(invalid_char_for_deck_component) {
+        out = out.replace(invalid_char_for_deck_component, "").into();
+    }
+    let trimmed = out.trim();
+    if trimmed.is_empty() {
+        "blank".into()
+    } else if trimmed.len() != out.len() {
+        // fixme: trimming leading/trailing spaces may break old clients if we don't bump mod
+        trimmed.to_string().into()
+    } else {
+        out
+    }
+}
+
+pub(crate) fn human_deck_name_to_native(name: &str) -> String {
+    let mut out = String::with_capacity(name.len());
+    for comp in name.split("::") {
+        out.push_str(&normalized_deck_name_component(comp));
+        out.push('\x1f');
+    }
+    out.trim_end_matches('\x1f').into()
+}
+
 impl Collection {
+    // fixme: this cache may belong in CardGenContext?
     pub(crate) fn get_deck(&mut self, did: DeckID) -> Result<Option<Arc<Deck>>> {
         if let Some(deck) = self.state.deck_cache.get(&did) {
             return Ok(Some(deck.clone()));
@@ -47,3 +155,312 @@ impl Collection {
         }
     }
 }
+
+impl From<Deck> for DeckProto {
+    fn from(d: Deck) -> Self {
+        DeckProto {
+            id: d.id.0,
+            name: d.name,
+            mtime_secs: d.mtime_secs.0 as u32,
+            usn: d.usn.0,
+            common: Some(d.common),
+            kind: Some(d.kind.into()),
+        }
+    }
+}
+
+impl From<DeckKind> for pb::deck::Kind {
+    fn from(k: DeckKind) -> Self {
+        match k {
+            DeckKind::Normal(n) => pb::deck::Kind::Normal(n),
+            DeckKind::Filtered(f) => pb::deck::Kind::Filtered(f),
+        }
+    }
+}
+
+fn immediate_parent_name(machine_name: &str) -> Option<&str> {
+    machine_name.rsplitn(2, '\x1f').nth(1)
+}
+
+impl Collection {
+    pub(crate) fn add_or_update_deck(&mut self, deck: &mut Deck, preserve_usn: bool) -> Result<()> {
+        // fixme: vet cache clearing
+        self.state.deck_cache.clear();
+
+        self.transact(None, |col| {
+            let usn = col.usn()?;
+
+            deck.prepare_for_update();
+
+            // fixme: bail
+            assert!(!deck.name.contains("::"));
+
+            // fixme: check deck name is not duplicate
+            // handle blank deck name, etc
+
+            if !preserve_usn {
+                deck.set_modified(usn);
+            }
+
+            if deck.id.0 == 0 {
+                col.match_or_create_parents(deck)?;
+                col.storage.add_deck(deck)
+            } else {
+                if let Some(existing_deck) = col.storage.get_deck(deck.id)? {
+                    if existing_deck.name != deck.name {
+                        return col.update_renamed_deck(existing_deck, deck, usn);
+                    }
+                } else {
+                    // fixme: this should only happen in the syncing case, and we should
+                    // ensure there are no missing parents at the end of the sync
+                }
+                col.storage.update_deck(deck)
+            }
+        })
+    }
+
+    pub fn get_or_create_normal_deck(&mut self, human_name: &str) -> Result<Deck> {
+        let native_name = human_deck_name_to_native(human_name);
+        if let Some(did) = self.storage.get_deck_id(&native_name)? {
+            self.storage.get_deck(did).map(|opt| opt.unwrap())
+        } else {
+            let mut deck = Deck::new_normal();
+            deck.name = native_name;
+            self.add_or_update_deck(&mut deck, false)?;
+            Ok(deck)
+        }
+    }
+
+    fn update_renamed_deck(&mut self, existing: Deck, updated: &mut Deck, usn: Usn) -> Result<()> {
+        // new name should not conflict with a different deck
+        if let Some(other_did) = self.storage.get_deck_id(&updated.name)? {
+            if other_did != updated.id {
+                // fixme: this could break when syncing
+                return Err(AnkiError::Existing);
+            }
+        }
+
+        self.match_or_create_parents(updated)?;
+        self.storage.update_deck(updated)?;
+        self.rename_child_decks(&existing, &updated.name, usn)
+    }
+
+    // fixme: make sure this handles foo::bar and FOO::baz
+    fn rename_child_decks(&mut self, old: &Deck, new_name: &str, usn: Usn) -> Result<()> {
+        let children = self.storage.child_decks(old)?;
+        let old_component_count = old.name.matches('\x1f').count() + 1;
+
+        for mut child in children {
+            let child_components: Vec<_> = child.name.split('\x1f').collect();
+            let child_only = &child_components[old_component_count..];
+            let new_name = format!("{}\x1f{}", new_name, child_only.join("\x1f"));
+            child.name = new_name;
+            child.set_modified(usn);
+            self.storage.update_deck(&child)?;
+        }
+
+        Ok(())
+    }
+
+    /// Add a single, normal deck with the provided name for a child deck.
+    /// Caller must have done necessarily validation on name.
+    fn add_parent_deck(&self, machine_name: &str) -> Result<()> {
+        let mut deck = Deck::new_normal();
+        deck.name = machine_name.into();
+        // fixme: undo
+        self.storage.add_deck(&mut deck)
+    }
+
+    /// If parent deck(s) exist, rewrite name to match their case.
+    /// If they don't exist, create them.
+    /// Returns an error if a DB operation fails, or if the first existing parent is a filtered deck.
+    fn match_or_create_parents(&mut self, deck: &mut Deck) -> Result<()> {
+        let child_split: Vec<_> = deck.name.split('\x1f').collect();
+        if let Some(parent_deck) = self.first_existing_parent(&deck.name, 0)? {
+            if parent_deck.is_filtered() {
+                return Err(AnkiError::DeckIsFiltered);
+            }
+            let parent_count = parent_deck.name.matches('\x1f').count() + 1;
+            let need_create = parent_count != child_split.len() - 1;
+            deck.name = format!(
+                "{}\x1f{}",
+                parent_deck.name,
+                &child_split[parent_count..].join("\x1f")
+            );
+            if need_create {
+                self.create_missing_parents(&deck.name)?;
+            }
+            Ok(())
+        } else if child_split.len() == 1 {
+            // no parents required
+            Ok(())
+        } else {
+            // no existing parents
+            self.create_missing_parents(&deck.name)
+        }
+    }
+
+    fn create_missing_parents(&self, mut machine_name: &str) -> Result<()> {
+        while let Some(parent_name) = immediate_parent_name(machine_name) {
+            if self.storage.get_deck_id(parent_name)?.is_none() {
+                self.add_parent_deck(parent_name)?;
+            }
+            machine_name = parent_name;
+        }
+        Ok(())
+    }
+
+    fn first_existing_parent(
+        &self,
+        machine_name: &str,
+        recursion_level: usize,
+    ) -> Result<Option<Deck>> {
+        if recursion_level > 10 {
+            return Err(AnkiError::invalid_input("deck nesting level too deep"));
+        }
+        if let Some(parent_name) = immediate_parent_name(machine_name) {
+            if let Some(parent_did) = self.storage.get_deck_id(parent_name)? {
+                self.storage.get_deck(parent_did)
+            } else {
+                self.first_existing_parent(parent_name, recursion_level + 1)
+            }
+        } else {
+            Ok(None)
+        }
+    }
+
+    /// Get a deck based on its human name. If you have a machine name,
+    /// use the method in storage instead.
+    pub(crate) fn get_deck_id(&self, human_name: &str) -> Result<Option<DeckID>> {
+        let machine_name = human_deck_name_to_native(&human_name);
+        self.storage.get_deck_id(&machine_name)
+    }
+
+    pub fn remove_deck_and_child_decks(&mut self, did: DeckID) -> Result<()> {
+        self.transact(None, |col| {
+            let usn = col.usn()?;
+
+            if let Some(deck) = col.storage.get_deck(did)? {
+                let child_decks = col.storage.child_decks(&deck)?;
+
+                // top level
+                col.remove_single_deck(&deck, usn)?;
+
+                // remove children
+                for deck in child_decks {
+                    col.remove_single_deck(&deck, usn)?;
+                }
+            }
+            Ok(())
+        })
+    }
+
+    pub(crate) fn remove_single_deck(&mut self, deck: &Deck, usn: Usn) -> Result<()> {
+        // fixme: undo
+        match deck.kind {
+            DeckKind::Normal(_) => self.delete_all_cards_in_normal_deck(deck.id)?,
+            DeckKind::Filtered(_) => self.return_all_cards_in_filtered_deck(deck.id)?,
+        }
+        self.storage.remove_deck(deck.id)?;
+        self.storage.add_deck_grave(deck.id, usn)
+    }
+
+    fn delete_all_cards_in_normal_deck(&mut self, did: DeckID) -> Result<()> {
+        // fixme: need to search on odid as well
+        // fixme: the odid requirement will require a table scan, which will be slow when deleting a large tree
+        let cids = self.storage.all_cards_in_single_deck(did)?;
+        self.remove_cards_inner(&cids)
+    }
+
+    fn return_all_cards_in_filtered_deck(&mut self, did: DeckID) -> Result<()> {
+        let cids = self.storage.all_cards_in_single_deck(did)?;
+        self.return_cards_to_home_deck(&cids)
+    }
+
+    fn return_cards_to_home_deck(&mut self, cids: &[CardID]) -> Result<()> {
+        let sched = self.sched_ver();
+        for cid in cids {
+            if let Some(mut card) = self.storage.get_card(*cid)? {
+                // fixme: undo
+                card.return_home(sched);
+                self.storage.update_card(&card)?;
+            }
+        }
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::{human_deck_name_to_native, immediate_parent_name};
+    use crate::{
+        collection::{open_test_collection, Collection},
+        err::Result,
+    };
+
+    fn sorted_names(col: &Collection) -> Vec<String> {
+        col.storage
+            .get_all_deck_names()
+            .unwrap()
+            .into_iter()
+            .map(|d| d.1)
+            .collect()
+    }
+
+    #[test]
+    fn parent() {
+        assert_eq!(immediate_parent_name("foo"), None);
+        assert_eq!(immediate_parent_name("foo\x1fbar"), Some("foo"));
+        assert_eq!(
+            immediate_parent_name("foo\x1fbar\x1fbaz"),
+            Some("foo\x1fbar")
+        );
+    }
+
+    #[test]
+    fn from_human() {
+        assert_eq!(&human_deck_name_to_native("foo"), "foo");
+        assert_eq!(&human_deck_name_to_native("foo::bar"), "foo\x1fbar");
+        assert_eq!(&human_deck_name_to_native("fo\x1fo::ba\nr"), "foo\x1fbar");
+        assert_eq!(
+            &human_deck_name_to_native("foo::::baz"),
+            "foo\x1fblank\x1fbaz"
+        );
+    }
+
+    #[test]
+    fn adding_updating() -> Result<()> {
+        let mut col = open_test_collection();
+
+        let deck1 = col.get_or_create_normal_deck("foo")?;
+        let deck2 = col.get_or_create_normal_deck("FOO")?;
+        assert_eq!(deck1.id, deck2.id);
+        assert_eq!(sorted_names(&col), vec!["Default", "foo"]);
+
+        // missing parents should be automatically created, and case should match
+        // existing parents
+        let _deck3 = col.get_or_create_normal_deck("FOO::BAR::BAZ")?;
+        assert_eq!(
+            sorted_names(&col),
+            vec!["Default", "foo", "foo::BAR", "foo::BAR::BAZ"]
+        );
+
+        Ok(())
+    }
+
+    #[test]
+    fn renaming() -> Result<()> {
+        let mut col = open_test_collection();
+
+        let _ = col.get_or_create_normal_deck("foo::bar::baz")?;
+        let mut top_deck = col.get_or_create_normal_deck("foo")?;
+        top_deck.name = "other".into();
+        col.add_or_update_deck(&mut top_deck, false)?;
+        assert_eq!(
+            sorted_names(&col),
+            vec!["Default", "other", "other::bar", "other::bar::baz"]
+        );
+
+        Ok(())
+    }
+}
diff --git a/rslib/src/decks/schema11.rs b/rslib/src/decks/schema11.rs
index ee9608df6..48a41b76d 100644
--- a/rslib/src/decks/schema11.rs
+++ b/rslib/src/decks/schema11.rs
@@ -2,11 +2,16 @@
 // License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
 use super::DeckID;
+use super::{
+    human_deck_name_to_native, Deck, DeckCommon, DeckKind, FilteredDeck, FilteredSearchTerm,
+    NormalDeck,
+};
 use crate::{
     serde::{default_on_invalid, deserialize_bool_from_anything, deserialize_number_from_string},
     timestamp::TimestampSecs,
     types::Usn,
 };
+
 use serde_derive::{Deserialize, Serialize};
 use serde_json::Value;
 use serde_tuple::Serialize_tuple;
@@ -14,19 +19,19 @@ use std::collections::HashMap;
 
 #[derive(Serialize, PartialEq, Debug, Clone)]
 #[serde(untagged)]
-pub enum Deck {
-    Normal(NormalDeck),
-    Filtered(FilteredDeck),
+pub enum DeckSchema11 {
+    Normal(NormalDeckSchema11),
+    Filtered(FilteredDeckSchema11),
 }
 
 // serde doesn't support integer/bool enum tags, so we manually pick the correct variant
 mod dynfix {
-    use super::{Deck, FilteredDeck, NormalDeck};
+    use super::{DeckSchema11, FilteredDeckSchema11, NormalDeckSchema11};
     use serde::de::{self, Deserialize, Deserializer};
     use serde_json::{Map, Value};
 
-    impl<'de> Deserialize<'de> for Deck {
-        fn deserialize<D>(deserializer: D) -> Result<Deck, D::Error>
+    impl<'de> Deserialize<'de> for DeckSchema11 {
+        fn deserialize<D>(deserializer: D) -> Result<DeckSchema11, D::Error>
         where
             D: Deserializer<'de>,
         {
@@ -58,12 +63,12 @@ mod dynfix {
 
             let rest = Value::Object(map);
             if is_dyn {
-                FilteredDeck::deserialize(rest)
-                    .map(Deck::Filtered)
+                FilteredDeckSchema11::deserialize(rest)
+                    .map(DeckSchema11::Filtered)
                     .map_err(de::Error::custom)
             } else {
-                NormalDeck::deserialize(rest)
-                    .map(Deck::Normal)
+                NormalDeckSchema11::deserialize(rest)
+                    .map(DeckSchema11::Normal)
                     .map_err(de::Error::custom)
             }
         }
@@ -71,7 +76,7 @@ mod dynfix {
 }
 
 #[derive(Serialize, Deserialize, PartialEq, Debug, Clone)]
-pub struct DeckCommon {
+pub struct DeckCommonSchema11 {
     #[serde(deserialize_with = "deserialize_number_from_string")]
     pub(crate) id: DeckID,
     #[serde(
@@ -83,7 +88,7 @@ pub struct DeckCommon {
     pub(crate) name: String,
     pub(crate) usn: Usn,
     #[serde(flatten)]
-    pub(crate) today: DeckToday,
+    pub(crate) today: DeckTodaySchema11,
     collapsed: bool,
     #[serde(default)]
     desc: String,
@@ -95,9 +100,9 @@ pub struct DeckCommon {
 
 #[derive(Serialize, Deserialize, PartialEq, Debug, Clone)]
 #[serde(rename_all = "camelCase")]
-pub struct NormalDeck {
+pub struct NormalDeckSchema11 {
     #[serde(flatten)]
-    pub(crate) common: DeckCommon,
+    pub(crate) common: DeckCommonSchema11,
 
     #[serde(deserialize_with = "deserialize_number_from_string")]
     pub(crate) conf: i64,
@@ -109,13 +114,13 @@ pub struct NormalDeck {
 
 #[derive(Serialize, Deserialize, PartialEq, Debug, Clone)]
 #[serde(rename_all = "camelCase")]
-pub struct FilteredDeck {
+pub struct FilteredDeckSchema11 {
     #[serde(flatten)]
-    common: DeckCommon,
+    common: DeckCommonSchema11,
 
     #[serde(deserialize_with = "deserialize_bool_from_anything")]
     resched: bool,
-    terms: Vec<FilteredSearch>,
+    terms: Vec<FilteredSearchTermSchema11>,
 
     // unused, but older clients require its existence
     #[serde(default)]
@@ -127,50 +132,50 @@ pub struct FilteredDeck {
 
     // new scheduler
     #[serde(default)]
-    preview_delay: u16,
+    preview_delay: u32,
 }
 #[derive(Serialize, Deserialize, Debug, PartialEq, Default, Clone)]
-pub struct DeckToday {
+pub struct DeckTodaySchema11 {
     #[serde(rename = "lrnToday")]
-    pub(crate) lrn: TodayAmount,
+    pub(crate) lrn: TodayAmountSchema11,
     #[serde(rename = "revToday")]
-    pub(crate) rev: TodayAmount,
+    pub(crate) rev: TodayAmountSchema11,
     #[serde(rename = "newToday")]
-    pub(crate) new: TodayAmount,
+    pub(crate) new: TodayAmountSchema11,
     #[serde(rename = "timeToday")]
-    pub(crate) time: TodayAmount,
+    pub(crate) time: TodayAmountSchema11,
 }
 
 #[derive(Serialize_tuple, Deserialize, Debug, PartialEq, Default, Clone)]
 #[serde(from = "Vec<Value>")]
-pub struct TodayAmount {
+pub struct TodayAmountSchema11 {
     day: i32,
     amount: i32,
 }
 
-impl From<Vec<Value>> for TodayAmount {
+impl From<Vec<Value>> for TodayAmountSchema11 {
     fn from(mut v: Vec<Value>) -> Self {
         let amt = v.pop().and_then(|v| v.as_i64()).unwrap_or(0);
         let day = v.pop().and_then(|v| v.as_i64()).unwrap_or(0);
-        TodayAmount {
+        TodayAmountSchema11 {
             amount: amt as i32,
             day: day as i32,
         }
     }
 }
 #[derive(Serialize_tuple, Deserialize, Debug, PartialEq, Clone)]
-pub struct FilteredSearch {
+pub struct FilteredSearchTermSchema11 {
     search: String,
     #[serde(deserialize_with = "deserialize_number_from_string")]
     limit: i32,
-    order: i8,
+    order: i32,
 }
 
-impl Deck {
-    pub fn common(&self) -> &DeckCommon {
+impl DeckSchema11 {
+    pub fn common(&self) -> &DeckCommonSchema11 {
         match self {
-            Deck::Normal(d) => &d.common,
-            Deck::Filtered(d) => &d.common,
+            DeckSchema11::Normal(d) => &d.common,
+            DeckSchema11::Filtered(d) => &d.common,
         }
     }
 
@@ -190,16 +195,16 @@ impl Deck {
     }
 }
 
-impl Default for Deck {
+impl Default for DeckSchema11 {
     fn default() -> Self {
-        Deck::Normal(NormalDeck::default())
+        DeckSchema11::Normal(NormalDeckSchema11::default())
     }
 }
 
-impl Default for NormalDeck {
+impl Default for NormalDeckSchema11 {
     fn default() -> Self {
-        NormalDeck {
-            common: DeckCommon {
+        NormalDeckSchema11 {
+            common: DeckCommonSchema11 {
                 id: DeckID(0),
                 mtime: TimestampSecs(0),
                 name: "".to_string(),
@@ -216,3 +221,169 @@ impl Default for NormalDeck {
         }
     }
 }
+
+// schema 11 -> latest
+
+impl From<DeckSchema11> for Deck {
+    fn from(deck: DeckSchema11) -> Self {
+        match deck {
+            DeckSchema11::Normal(d) => Deck {
+                id: d.common.id,
+                name: human_deck_name_to_native(&d.common.name),
+                mtime_secs: d.common.mtime,
+                usn: d.common.usn,
+                common: (&d.common).into(),
+                kind: DeckKind::Normal(d.into()),
+            },
+            DeckSchema11::Filtered(d) => Deck {
+                id: d.common.id,
+                name: human_deck_name_to_native(&d.common.name),
+                mtime_secs: d.common.mtime,
+                usn: d.common.usn,
+                common: (&d.common).into(),
+                kind: DeckKind::Filtered(d.into()),
+            },
+        }
+    }
+}
+
+impl From<&DeckCommonSchema11> for DeckCommon {
+    fn from(common: &DeckCommonSchema11) -> Self {
+        let other = if common.other.is_empty() {
+            vec![]
+        } else {
+            serde_json::to_vec(&common.other).unwrap_or_default()
+        };
+        DeckCommon {
+            collapsed: common.collapsed,
+            last_day_studied: common.today.new.day as u32,
+            new_studied: common.today.new.amount,
+            review_studied: common.today.rev.amount,
+            learning_studied: common.today.lrn.amount,
+            secs_studied: common.today.time.amount,
+            other,
+        }
+    }
+}
+
+impl From<NormalDeckSchema11> for NormalDeck {
+    fn from(deck: NormalDeckSchema11) -> Self {
+        NormalDeck {
+            config_id: deck.conf,
+            extend_new: deck.extend_new.max(0) as u32,
+            extend_review: deck.extend_rev.max(0) as u32,
+            description: deck.common.desc,
+        }
+    }
+}
+
+impl From<FilteredDeckSchema11> for FilteredDeck {
+    fn from(deck: FilteredDeckSchema11) -> Self {
+        FilteredDeck {
+            reschedule: deck.resched,
+            search_terms: deck.terms.into_iter().map(Into::into).collect(),
+            delays: deck.delays.unwrap_or_default(),
+            preview_delay: deck.preview_delay,
+        }
+    }
+}
+
+impl From<FilteredSearchTermSchema11> for FilteredSearchTerm {
+    fn from(term: FilteredSearchTermSchema11) -> Self {
+        FilteredSearchTerm {
+            search: term.search,
+            limit: term.limit.max(0) as u32,
+            order: term.order,
+        }
+    }
+}
+
+// latest -> schema 11
+
+impl From<Deck> for DeckSchema11 {
+    fn from(deck: Deck) -> Self {
+        match deck.kind {
+            DeckKind::Normal(ref norm) => DeckSchema11::Normal(NormalDeckSchema11 {
+                conf: norm.config_id,
+                extend_new: norm.extend_new as i32,
+                extend_rev: norm.extend_review as i32,
+                common: deck.into(),
+            }),
+            DeckKind::Filtered(ref filt) => DeckSchema11::Filtered(FilteredDeckSchema11 {
+                resched: filt.reschedule,
+                terms: filt.search_terms.iter().map(|v| v.clone().into()).collect(),
+                separate: true,
+                delays: if filt.delays.is_empty() {
+                    None
+                } else {
+                    Some(filt.delays.clone())
+                },
+                preview_delay: filt.preview_delay as u32,
+                common: deck.into(),
+            }),
+        }
+    }
+}
+
+impl From<Deck> for DeckCommonSchema11 {
+    fn from(deck: Deck) -> Self {
+        let other: HashMap<String, Value> = if deck.common.other.is_empty() {
+            Default::default()
+        } else {
+            serde_json::from_slice(&deck.common.other).unwrap_or_default()
+        };
+        DeckCommonSchema11 {
+            id: deck.id,
+            mtime: deck.mtime_secs,
+            name: deck.name.replace("\x1f", "::"),
+            usn: deck.usn,
+            today: (&deck).into(),
+            collapsed: deck.common.collapsed,
+            dynamic: if matches!(deck.kind, DeckKind::Filtered(_)) {
+                1
+            } else {
+                0
+            },
+            desc: match deck.kind {
+                DeckKind::Normal(n) => n.description,
+                DeckKind::Filtered(_) => String::new(),
+            },
+            other,
+        }
+    }
+}
+
+impl From<&Deck> for DeckTodaySchema11 {
+    fn from(deck: &Deck) -> Self {
+        let day = deck.common.last_day_studied as i32;
+        let c = &deck.common;
+        DeckTodaySchema11 {
+            lrn: TodayAmountSchema11 {
+                day,
+                amount: c.learning_studied,
+            },
+            rev: TodayAmountSchema11 {
+                day,
+                amount: c.review_studied,
+            },
+            new: TodayAmountSchema11 {
+                day,
+                amount: c.new_studied,
+            },
+            time: TodayAmountSchema11 {
+                day,
+                amount: c.secs_studied,
+            },
+        }
+    }
+}
+
+impl From<FilteredSearchTerm> for FilteredSearchTermSchema11 {
+    fn from(term: FilteredSearchTerm) -> Self {
+        FilteredSearchTermSchema11 {
+            search: term.search,
+            limit: term.limit as i32,
+            order: term.order,
+        }
+    }
+}
diff --git a/rslib/src/err.rs b/rslib/src/err.rs
index 5c3f2a74f..32389afc7 100644
--- a/rslib/src/err.rs
+++ b/rslib/src/err.rs
@@ -48,6 +48,12 @@ pub enum AnkiError {
 
     #[fail(display = "A requested item was not found.")]
     NotFound,
+
+    #[fail(display = "The provided item already exists.")]
+    Existing,
+
+    #[fail(display = "Unable to place item in/under a filtered deck.")]
+    DeckIsFiltered,
 }
 
 // error helpers
diff --git a/rslib/src/notes.rs b/rslib/src/notes.rs
index dbfc78560..f80592a46 100644
--- a/rslib/src/notes.rs
+++ b/rslib/src/notes.rs
@@ -220,6 +220,16 @@ impl Collection {
 
         Ok(())
     }
+
+    /// Remove a note. Cards must already have been deleted.
+    pub(crate) fn remove_note_only(&mut self, nid: NoteID, usn: Usn) -> Result<()> {
+        if let Some(_note) = self.storage.get_note(nid)? {
+            // fixme: undo
+            self.storage.remove_note(nid)?;
+            self.storage.add_note_grave(nid, usn)?;
+        }
+        Ok(())
+    }
 }
 
 #[cfg(test)]
diff --git a/rslib/src/notetype/cardgen.rs b/rslib/src/notetype/cardgen.rs
index 900c69b0c..2bd28ca24 100644
--- a/rslib/src/notetype/cardgen.rs
+++ b/rslib/src/notetype/cardgen.rs
@@ -289,11 +289,8 @@ impl Collection {
 
     /// If deck exists and and is a normal deck, return it.
     fn deck_id_if_normal(&mut self, did: DeckID) -> Option<DeckID> {
-        // fixme: currently disabled until deck writes are immediate
-        return Some(did);
-
         self.get_deck(did)
             .ok()
-            .and_then(|opt| opt.and_then(|d| if !d.is_filtered() { Some(d.id()) } else { None }))
+            .and_then(|opt| opt.and_then(|d| if !d.is_filtered() { Some(d.id) } else { None }))
     }
 }
diff --git a/rslib/src/search/cards.rs b/rslib/src/search/cards.rs
index 0e6346548..5bc3a131d 100644
--- a/rslib/src/search/cards.rs
+++ b/rslib/src/search/cards.rs
@@ -92,8 +92,7 @@ fn write_order(sql: &mut String, kind: &SortKind, reverse: bool) -> Result<()> {
     Ok(())
 }
 
-// In the future these items should be moved from JSON into separate SQL tables,
-// - for now we use a temporary deck to sort them.
+// fixme: use the new tables
 fn prepare_sort(col: &mut Collection, kind: &SortKind) -> Result<()> {
     use SortKind::*;
     match kind {
@@ -106,7 +105,7 @@ fn prepare_sort(col: &mut Collection, kind: &SortKind) -> Result<()> {
 
             match kind {
                 CardDeck => {
-                    for (k, v) in col.storage.get_all_decks()? {
+                    for (k, v) in col.storage.get_all_decks_as_schema11()? {
                         stmt.execute(params![k, v.name()])?;
                     }
                 }
diff --git a/rslib/src/search/sqlwriter.rs b/rslib/src/search/sqlwriter.rs
index 17a491051..1cb8baf39 100644
--- a/rslib/src/search/sqlwriter.rs
+++ b/rslib/src/search/sqlwriter.rs
@@ -221,6 +221,7 @@ impl SqlWriter<'_> {
         Ok(())
     }
 
+    // fixme: update for new table
     fn write_deck(&mut self, deck: &str) -> Result<()> {
         match deck {
             "*" => write!(self.sql, "true").unwrap(),
@@ -229,7 +230,7 @@ impl SqlWriter<'_> {
                 let all_decks: Vec<_> = self
                     .col
                     .storage
-                    .get_all_decks()?
+                    .get_all_decks_as_schema11()?
                     .into_iter()
                     .map(|(_, v)| v)
                     .collect();
diff --git a/rslib/src/storage/card/mod.rs b/rslib/src/storage/card/mod.rs
index 16a060709..3631f16e8 100644
--- a/rslib/src/storage/card/mod.rs
+++ b/rslib/src/storage/card/mod.rs
@@ -111,6 +111,13 @@ impl super::SqliteStorage {
         card.id = CardID(self.db.last_insert_rowid());
         Ok(())
     }
+
+    pub(crate) fn remove_card(&self, cid: CardID) -> Result<()> {
+        self.db
+            .prepare_cached("delete from cards where id = ?")?
+            .execute(&[cid])?;
+        Ok(())
+    }
 }
 
 #[cfg(test)]
diff --git a/rslib/src/storage/deck/add_deck.sql b/rslib/src/storage/deck/add_deck.sql
new file mode 100644
index 000000000..fbee07b1f
--- /dev/null
+++ b/rslib/src/storage/deck/add_deck.sql
@@ -0,0 +1 @@
+insert into decks 
\ No newline at end of file
diff --git a/rslib/src/storage/deck/alloc_id.sql b/rslib/src/storage/deck/alloc_id.sql
new file mode 100644
index 000000000..80004ad56
--- /dev/null
+++ b/rslib/src/storage/deck/alloc_id.sql
@@ -0,0 +1,13 @@
+select
+  case
+    when ?1 in (
+      select
+        id
+      from decks
+    ) then (
+      select
+        max(id) + 1
+      from decks
+    )
+    else ?1
+  end;
\ No newline at end of file
diff --git a/rslib/src/storage/deck/get_deck.sql b/rslib/src/storage/deck/get_deck.sql
new file mode 100644
index 000000000..51ec1c145
--- /dev/null
+++ b/rslib/src/storage/deck/get_deck.sql
@@ -0,0 +1,8 @@
+select
+  name,
+  id,
+  mtime_secs,
+  usn,
+  common,
+  kind
+from decks
\ No newline at end of file
diff --git a/rslib/src/storage/deck/mod.rs b/rslib/src/storage/deck/mod.rs
index 7e3f88a8c..11c49ce7e 100644
--- a/rslib/src/storage/deck/mod.rs
+++ b/rslib/src/storage/deck/mod.rs
@@ -3,29 +3,200 @@
 
 use super::SqliteStorage;
 use crate::{
-    decks::{Deck, DeckID},
-    err::Result,
+    card::CardID,
+    decks::{Deck, DeckCommon, DeckID, DeckKindProto, DeckSchema11},
+    err::{AnkiError, DBErrorKind, Result},
+    i18n::{I18n, TR},
+    timestamp::TimestampMillis,
 };
-use rusqlite::NO_PARAMS;
-use std::collections::HashMap;
+use prost::Message;
+use rusqlite::{params, Row, NO_PARAMS};
+use std::collections::{HashMap, HashSet};
+use unicase::UniCase;
+
+fn row_to_deck(row: &Row) -> Result<Deck> {
+    let common = DeckCommon::decode(row.get_raw(4).as_blob()?)?;
+    let kind = DeckKindProto::decode(row.get_raw(5).as_blob()?)?;
+    let id = row.get(1)?;
+    Ok(Deck {
+        id,
+        name: row.get(0)?,
+        mtime_secs: row.get(2)?,
+        usn: row.get(3)?,
+        common,
+        kind: kind.kind.ok_or_else(|| AnkiError::DBError {
+            kind: DBErrorKind::MissingEntity,
+            info: format!("invalid deck kind: {}", id),
+        })?,
+    })
+}
 
 impl SqliteStorage {
-    pub(crate) fn get_all_decks(&self) -> Result<HashMap<DeckID, Deck>> {
-        self.db
-            .query_row_and_then("select decks from col", NO_PARAMS, |row| -> Result<_> {
-                Ok(serde_json::from_str(row.get_raw(0).as_str()?)?)
-            })
+    pub(crate) fn get_all_decks_as_schema11(&self) -> Result<HashMap<DeckID, DeckSchema11>> {
+        self.get_all_decks()
+            .map(|r| r.into_iter().map(|d| (d.id, d.into())).collect())
     }
 
-    pub(crate) fn set_all_decks(&self, decks: HashMap<DeckID, Deck>) -> Result<()> {
+    pub(crate) fn get_deck(&self, did: DeckID) -> Result<Option<Deck>> {
+        self.db
+            .prepare_cached(concat!(include_str!("get_deck.sql"), " where id = ?"))?
+            .query_and_then(&[did], row_to_deck)?
+            .next()
+            .transpose()
+    }
+
+    pub(crate) fn get_all_decks(&self) -> Result<Vec<Deck>> {
+        self.db
+            .prepare(include_str!("get_deck.sql"))?
+            .query_and_then(NO_PARAMS, row_to_deck)?
+            .collect()
+    }
+
+    /// Get all deck names in human-readable form (::)
+    pub(crate) fn get_all_deck_names(&self) -> Result<Vec<(DeckID, String)>> {
+        self.db
+            .prepare("select name, id from decks")?
+            .query_and_then(NO_PARAMS, |row| {
+                Ok((row.get(1)?, row.get_raw(0).as_str()?.replace('\x1f', "::")))
+            })?
+            .collect()
+    }
+
+    pub(crate) fn get_deck_id(&self, machine_name: &str) -> Result<Option<DeckID>> {
+        self.db
+            .prepare("select id from decks where name = ?")?
+            .query_and_then(&[machine_name], |row| row.get(0))?
+            .next()
+            .transpose()
+            .map_err(Into::into)
+    }
+
+    // caller should ensure name unique
+    pub(crate) fn add_deck(&self, deck: &mut Deck) -> Result<()> {
+        assert!(deck.id.0 == 0);
+        deck.id.0 = self
+            .db
+            .prepare(include_str!("alloc_id.sql"))?
+            .query_row(&[TimestampMillis::now()], |r| r.get(0))?;
+        self.update_deck(deck).map_err(|err| {
+            // restore id of 0
+            deck.id.0 = 0;
+            err
+        })
+    }
+
+    // fixme: bail instead of assert
+    pub(crate) fn update_deck(&self, deck: &Deck) -> Result<()> {
+        assert!(deck.id.0 != 0);
+        let mut stmt = self.db.prepare_cached(include_str!("update_deck.sql"))?;
+        let mut common = vec![];
+        deck.common.encode(&mut common)?;
+        let kind_enum = DeckKindProto {
+            kind: Some(deck.kind.clone()),
+        };
+        let mut kind = vec![];
+        kind_enum.encode(&mut kind)?;
+        stmt.execute(params![
+            deck.name,
+            deck.id,
+            deck.mtime_secs,
+            deck.usn,
+            common,
+            kind
+        ])?;
+
+        Ok(())
+    }
+
+    pub(crate) fn remove_deck(&self, did: DeckID) -> Result<()> {
+        self.db
+            .prepare_cached("delete from decks where id = ?")?
+            .execute(&[did])?;
+        Ok(())
+    }
+
+    pub(crate) fn all_cards_in_single_deck(&self, did: DeckID) -> Result<Vec<CardID>> {
+        self.db
+            .prepare_cached("select id from cards where did = ?")?
+            .query_and_then(&[did], |r| r.get(0).map_err(Into::into))?
+            .collect()
+    }
+
+    pub(crate) fn child_decks(&self, parent: &Deck) -> Result<Vec<Deck>> {
+        let prefix_start = format!("{}\x1f", parent.name);
+        let prefix_end = format!("{}\x20", parent.name);
+        self.db
+            .prepare_cached(concat!(
+                include_str!("get_deck.sql"),
+                " where name >= ? and name < ?"
+            ))?
+            .query_and_then(&[prefix_start, prefix_end], row_to_deck)?
+            .collect()
+    }
+
+    // Upgrading/downgrading/legacy
+
+    // pub(crate) fn get_all_decks_as_schema11(&self) -> Result<HashMap<DeckID, DeckSchema11>> {
+    //     let mut nts = HashMap::new();
+    //     for (ntid, _name) in self.get_all_deck_names()? {
+    //         let full = self.get_deck(ntid)?.unwrap();
+    //         nts.insert(ntid, full.into());
+    //     }
+    //     Ok(nts)
+    // }
+
+    pub(super) fn add_default_deck(&self, i18n: &I18n) -> Result<()> {
+        let mut deck = Deck::new_normal();
+        deck.id.0 = 1;
+        // fixme: separate key
+        deck.name = i18n.tr(TR::DeckConfigDefaultName).into();
+        self.update_deck(&deck)
+    }
+
+    // fixme: make sure conflicting deck names don't break things
+    pub(crate) fn upgrade_decks_to_schema15(&self) -> Result<()> {
+        let decks = self.get_schema11_decks()?;
+        let mut names = HashSet::new();
+        for (_id, deck) in decks {
+            let mut deck = Deck::from(deck);
+            loop {
+                let name = UniCase::new(deck.name.clone());
+                if !names.contains(&name) {
+                    names.insert(name);
+                    break;
+                }
+                deck.name.push('_');
+            }
+            self.update_deck(&deck)?;
+        }
+        self.db.execute("update col set decks = ''", NO_PARAMS)?;
+        Ok(())
+    }
+
+    pub(crate) fn downgrade_decks_from_schema15(&self) -> Result<()> {
+        let decks = self.get_all_decks_as_schema11()?;
+        self.set_schema11_decks(decks)
+    }
+
+    fn get_schema11_decks(&self) -> Result<HashMap<DeckID, DeckSchema11>> {
+        let mut stmt = self.db.prepare("select decks from col")?;
+        let decks = stmt
+            .query_and_then(NO_PARAMS, |row| -> Result<HashMap<DeckID, DeckSchema11>> {
+                let v: HashMap<DeckID, DeckSchema11> =
+                    serde_json::from_str(row.get_raw(0).as_str()?)?;
+                Ok(v)
+            })?
+            .next()
+            .ok_or_else(|| AnkiError::DBError {
+                info: "col table empty".to_string(),
+                kind: DBErrorKind::MissingEntity,
+            })??;
+        Ok(decks)
+    }
+
+    pub(crate) fn set_schema11_decks(&self, decks: HashMap<DeckID, DeckSchema11>) -> Result<()> {
         let json = serde_json::to_string(&decks)?;
         self.db.execute("update col set decks = ?", &[json])?;
         Ok(())
     }
-
-    pub(crate) fn get_deck(&self, did: DeckID) -> Result<Option<Deck>> {
-        // fixme: this is just temporary until we create an extra table
-        let mut decks = self.get_all_decks()?;
-        Ok(decks.remove(&did))
-    }
 }
diff --git a/rslib/src/storage/deck/update_deck.sql b/rslib/src/storage/deck/update_deck.sql
new file mode 100644
index 000000000..5c77a89a2
--- /dev/null
+++ b/rslib/src/storage/deck/update_deck.sql
@@ -0,0 +1,4 @@
+insert
+  or replace into decks (name, id, mtime_secs, usn, common, kind)
+values
+  (?, ?, ?, ?, ?, ?)
\ No newline at end of file
diff --git a/rslib/src/storage/graves/add.sql b/rslib/src/storage/graves/add.sql
new file mode 100644
index 000000000..d01f13c95
--- /dev/null
+++ b/rslib/src/storage/graves/add.sql
@@ -0,0 +1,4 @@
+insert
+  or ignore into graves (usn, oid, type)
+values
+  (?, ?, ?)
\ No newline at end of file
diff --git a/rslib/src/storage/graves/mod.rs b/rslib/src/storage/graves/mod.rs
new file mode 100644
index 000000000..b55fc7155
--- /dev/null
+++ b/rslib/src/storage/graves/mod.rs
@@ -0,0 +1,39 @@
+// Copyright: Ankitects Pty Ltd and contributors
+// License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
+
+use super::SqliteStorage;
+use crate::{card::CardID, decks::DeckID, err::Result, notes::NoteID, types::Usn};
+use rusqlite::{params, NO_PARAMS};
+
+enum GraveKind {
+    Card,
+    Note,
+    Deck,
+}
+
+impl SqliteStorage {
+    fn add_grave(&self, oid: i64, kind: GraveKind, usn: Usn) -> Result<()> {
+        self.db
+            .prepare_cached(include_str!("add.sql"))?
+            .execute(params![usn, oid, kind as u8])?;
+        Ok(())
+    }
+
+    #[allow(dead_code)]
+    pub(crate) fn clear_all_graves(&self) -> Result<()> {
+        self.db.execute("delete from graves", NO_PARAMS)?;
+        Ok(())
+    }
+
+    pub(crate) fn add_card_grave(&self, cid: CardID, usn: Usn) -> Result<()> {
+        self.add_grave(cid.0, GraveKind::Card, usn)
+    }
+
+    pub(crate) fn add_note_grave(&self, nid: NoteID, usn: Usn) -> Result<()> {
+        self.add_grave(nid.0, GraveKind::Note, usn)
+    }
+
+    pub(crate) fn add_deck_grave(&self, did: DeckID, usn: Usn) -> Result<()> {
+        self.add_grave(did.0, GraveKind::Deck, usn)
+    }
+}
diff --git a/rslib/src/storage/mod.rs b/rslib/src/storage/mod.rs
index 2192be013..ce2fb8df6 100644
--- a/rslib/src/storage/mod.rs
+++ b/rslib/src/storage/mod.rs
@@ -5,6 +5,7 @@ mod card;
 mod config;
 mod deck;
 mod deckconf;
+mod graves;
 mod note;
 mod notetype;
 mod sqlite;
diff --git a/rslib/src/storage/note/is_orphaned.sql b/rslib/src/storage/note/is_orphaned.sql
new file mode 100644
index 000000000..7b27c1ee9
--- /dev/null
+++ b/rslib/src/storage/note/is_orphaned.sql
@@ -0,0 +1,5 @@
+select
+  count(id) = 0
+from cards
+where
+  nid = ?;
\ No newline at end of file
diff --git a/rslib/src/storage/note/mod.rs b/rslib/src/storage/note/mod.rs
index 9faf7e80a..da4f86e08 100644
--- a/rslib/src/storage/note/mod.rs
+++ b/rslib/src/storage/note/mod.rs
@@ -74,4 +74,18 @@ impl super::SqliteStorage {
         note.id.0 = self.db.last_insert_rowid();
         Ok(())
     }
+
+    pub(crate) fn remove_note(&self, nid: NoteID) -> Result<()> {
+        self.db
+            .prepare_cached("delete from notes where id = ?")?
+            .execute(&[nid])?;
+        Ok(())
+    }
+
+    pub(crate) fn note_is_orphaned(&self, nid: NoteID) -> Result<bool> {
+        self.db
+            .prepare_cached(include_str!("is_orphaned.sql"))?
+            .query_row(&[nid], |r| r.get(0))
+            .map_err(Into::into)
+    }
 }
diff --git a/rslib/src/storage/sqlite.rs b/rslib/src/storage/sqlite.rs
index 00307723f..761ccc589 100644
--- a/rslib/src/storage/sqlite.rs
+++ b/rslib/src/storage/sqlite.rs
@@ -198,6 +198,7 @@ impl SqliteStorage {
 
         if create {
             storage.add_default_deck_config(i18n)?;
+            storage.add_default_deck(i18n)?;
             storage.add_stock_notetypes(i18n)?;
         }
 
diff --git a/rslib/src/storage/upgrades/mod.rs b/rslib/src/storage/upgrades/mod.rs
index bc19e5c60..f8e816f22 100644
--- a/rslib/src/storage/upgrades/mod.rs
+++ b/rslib/src/storage/upgrades/mod.rs
@@ -17,6 +17,7 @@ impl SqliteStorage {
             self.db
                 .execute_batch(include_str!("schema15_upgrade.sql"))?;
             self.upgrade_notetypes_to_schema15()?;
+            self.upgrade_decks_to_schema15()?;
         }
 
         Ok(())
@@ -25,6 +26,7 @@ impl SqliteStorage {
     pub(super) fn downgrade_to_schema_11(&self) -> Result<()> {
         self.begin_trx()?;
 
+        self.downgrade_decks_from_schema15()?;
         self.downgrade_notetypes_from_schema15()?;
         self.downgrade_config_from_schema14()?;
         self.downgrade_tags_from_schema14()?;
diff --git a/rslib/src/storage/upgrades/schema11_downgrade.sql b/rslib/src/storage/upgrades/schema11_downgrade.sql
index c86df17cd..14bacf26c 100644
--- a/rslib/src/storage/upgrades/schema11_downgrade.sql
+++ b/rslib/src/storage/upgrades/schema11_downgrade.sql
@@ -4,6 +4,7 @@ drop table tags;
 drop table fields;
 drop table templates;
 drop table notetypes;
+drop table decks;
 update col
 set
   ver = 11;
\ No newline at end of file
diff --git a/rslib/src/storage/upgrades/schema15_upgrade.sql b/rslib/src/storage/upgrades/schema15_upgrade.sql
index 9f7716934..c8bb2ce0d 100644
--- a/rslib/src/storage/upgrades/schema15_upgrade.sql
+++ b/rslib/src/storage/upgrades/schema15_upgrade.sql
@@ -26,6 +26,15 @@ create table notetypes (
 );
 create unique index idx_notetypes_name on notetypes (name);
 create index idx_notetypes_usn on notetypes (usn);
+create table decks (
+  name text not null primary key collate unicase,
+  id integer not null,
+  mtime_secs integer not null,
+  usn integer not null,
+  common bytes not null,
+  kind bytes not null
+);
+create unique index idx_decks_id on decks (id);
 update col
 set
   ver = 15;