diff --git a/proto/backend.proto b/proto/backend.proto
index 53fb173d5..fe56065f6 100644
--- a/proto/backend.proto
+++ b/proto/backend.proto
@@ -158,6 +158,27 @@ service BackendService {
     rpc SyncMedia (SyncMediaIn) returns (Empty);
     rpc AbortMediaSync (Empty) returns (Empty);
     rpc BeforeUpload (Empty) returns (Empty);
+
+    // translation/messages
+
+    rpc TranslateString (TranslateStringIn) returns (String);
+    rpc FormatTimespan (FormatTimespanIn) returns (String);
+
+    // tags
+
+    rpc RegisterTags (RegisterTagsIn) returns (Bool);
+    rpc AllTags (Empty) returns (AllTagsOut);
+    rpc GetChangedTags (Int32) returns (GetChangedTagsOut);
+
+    // config/preferences
+
+    rpc GetConfigJson (String) returns (Json);
+    rpc SetConfigJson (SetConfigJsonIn) returns (Empty);
+    rpc RemoveConfig (String) returns (Empty);
+    rpc SetAllConfig (Json) returns (Empty);
+    rpc GetAllConfig (Empty) returns (Json);
+    rpc GetPreferences (Empty) returns (Preferences);
+    rpc SetPreferences (Preferences) returns (Empty);
 }
 
 // Protobuf stored in .anki2 files
@@ -398,49 +419,9 @@ message I18nBackendInit {
     string locale_folder_path = 5;
 }
 
-// Legacy enum - needs migrating to RPC above
+// Errors
 ///////////////////////////////////////////////////////////
 
-message BackendInput {
-    oneof value {
-        TranslateStringIn translate_string = 30;
-        FormatTimeSpanIn format_time_span = 31;
-
-        RegisterTagsIn register_tags = 48;
-        Empty all_tags = 50;
-        int32 get_changed_tags = 51;
-
-        string get_config_json = 52;
-        SetConfigJson set_config_json = 53;
-        bytes set_all_config = 54;
-        Empty get_all_config = 55;
-
-        Empty get_preferences = 84;
-        Preferences set_preferences = 85;
-    }
-}
-
-message BackendOutput {
-    oneof value {
-        string translate_string = 30;
-        string format_time_span = 31;
-
-        bool register_tags = 48;
-        AllTagsOut all_tags = 50;
-        GetChangedTagsOut get_changed_tags = 51;
-
-        bytes get_config_json = 52;
-        Empty set_config_json = 53;
-        Empty set_all_config = 54;
-        bytes get_all_config = 55;
-
-        Preferences get_preferences = 84;
-        Empty set_preferences = 85;
-
-        BackendError error = 2047;
-    }
-}
-
 message BackendError {
     // localized error description suitable for displaying to the user
     string localized = 1;
@@ -504,6 +485,10 @@ message MediaSyncUploadProgress {
     uint32 deletions = 2;
 }
 
+// Messages
+///////////////////////////////////////////////////////////
+
+
 message SchedTimingTodayOut {
     uint32 days_elapsed = 1;
     int64 next_day_at = 2;
@@ -632,7 +617,7 @@ message TranslateArgValue {
     }
 }
 
-message FormatTimeSpanIn {
+message FormatTimespanIn {
     enum Context {
         PRECISE = 0;
         ANSWER_BUTTONS = 1;
@@ -736,12 +721,9 @@ message GetChangedTagsOut {
     repeated string tags = 1;
 }
 
-message SetConfigJson {
+message SetConfigJsonIn {
     string key = 1;
-    oneof op {
-        bytes val = 2;
-        Empty remove = 3;
-    }
+    bytes val = 2;
 }
 
 enum StockNoteType {
diff --git a/pylib/anki/collection.py b/pylib/anki/collection.py
index 2c37f805a..2a1b1da33 100644
--- a/pylib/anki/collection.py
+++ b/pylib/anki/collection.py
@@ -26,7 +26,13 @@ from anki.lang import _
 from anki.media import MediaManager, media_paths_from_col_path
 from anki.models import ModelManager
 from anki.notes import Note
-from anki.rsbackend import TR, DBError, RustBackend, pb
+from anki.rsbackend import (
+    TR,
+    DBError,
+    FormatTimeSpanContext,
+    RustBackend,
+    pb,
+)
 from anki.sched import Scheduler as V1Scheduler
 from anki.schedv2 import Scheduler as V2Scheduler
 from anki.tags import TagManager
@@ -65,13 +71,23 @@ class Collection:
         n = os.path.splitext(os.path.basename(self.path))[0]
         return n
 
-    def tr(self, key: TR, **kwargs: Union[str, int, float]) -> str:
-        return self.backend.translate(key, **kwargs)
-
     def weakref(self) -> Collection:
         "Shortcut to create a weak reference that doesn't break code completion."
         return weakref.proxy(self)
 
+    # I18n/messages
+    ##########################################################################
+
+    def tr(self, key: TR, **kwargs: Union[str, int, float]) -> str:
+        return self.backend.translate(key, **kwargs)
+
+    def format_timespan(
+        self,
+        seconds: float,
+        context: FormatTimeSpanContext = FormatTimeSpanContext.INTERVALS,
+    ) -> str:
+        return self.backend.format_timespan(seconds, context)
+
     # Scheduler
     ##########################################################################
 
diff --git a/pylib/anki/config.py b/pylib/anki/config.py
index 74afb0d80..0c853c629 100644
--- a/pylib/anki/config.py
+++ b/pylib/anki/config.py
@@ -23,6 +23,7 @@ import weakref
 from typing import Any
 
 import anki
+from anki.rsbackend import NotFoundError, from_json_bytes, to_json_bytes
 
 
 class ConfigManager:
@@ -30,10 +31,13 @@ class ConfigManager:
         self.col = col.weakref()
 
     def get_immutable(self, key: str) -> Any:
-        return self.col.backend.get_config_json(key)
+        try:
+            return from_json_bytes(self.col.backend.get_config_json(key))
+        except NotFoundError:
+            raise KeyError
 
     def set(self, key: str, val: Any) -> None:
-        self.col.backend.set_config_json(key, val)
+        self.col.backend.set_config_json(key, to_json_bytes(val))
 
     def remove(self, key: str) -> None:
         self.col.backend.remove_config(key)
diff --git a/pylib/anki/rsbackend.py b/pylib/anki/rsbackend.py
index 987c478e6..06f11024b 100644
--- a/pylib/anki/rsbackend.py
+++ b/pylib/anki/rsbackend.py
@@ -153,7 +153,7 @@ def proto_exception_to_native(err: pb.BackendError) -> Exception:
 
 MediaSyncProgress = pb.MediaSyncProgress
 
-FormatTimeSpanContext = pb.FormatTimeSpanIn.Context
+FormatTimeSpanContext = pb.FormatTimespanIn.Context
 
 
 class ProgressKind(enum.Enum):
@@ -203,35 +203,6 @@ class RustBackend:
         self._backend = ankirspy.open_backend(init_msg.SerializeToString())
         self._backend.set_progress_callback(_on_progress)
 
-    def _run_command(
-        self, input: pb.BackendInput, release_gil: bool = False
-    ) -> pb.BackendOutput:
-        input_bytes = input.SerializeToString()
-        output_bytes = self._backend.command(input_bytes, release_gil)
-        output = pb.BackendOutput()
-        output.ParseFromString(output_bytes)
-        kind = output.WhichOneof("value")
-        if kind == "error":
-            raise proto_exception_to_native(output.error)
-        else:
-            return output
-
-    def translate(self, key: TR, **kwargs: Union[str, int, float]) -> str:
-        return self._run_command(
-            pb.BackendInput(translate_string=translate_string_in(key, **kwargs))
-        ).translate_string
-
-    def format_time_span(
-        self,
-        seconds: float,
-        context: FormatTimeSpanContext = FormatTimeSpanContext.INTERVALS,
-    ) -> str:
-        return self._run_command(
-            pb.BackendInput(
-                format_time_span=pb.FormatTimeSpanIn(seconds=seconds, context=context)
-            )
-        ).format_time_span
-
     def db_query(
         self, sql: str, args: Sequence[ValueForDB], first_row_only: bool
     ) -> List[DBRow]:
@@ -254,76 +225,23 @@ class RustBackend:
     def _db_command(self, input: Dict[str, Any]) -> Any:
         return orjson.loads(self._backend.db_command(orjson.dumps(input)))
 
-    def all_tags(self) -> Iterable[TagUsnTuple]:
-        return self._run_command(pb.BackendInput(all_tags=pb.Empty())).all_tags.tags
+    def translate(self, key: TR, **kwargs: Union[str, int, float]) -> str:
+        return self.translate_string(translate_string_in(key, **kwargs))
 
-    def register_tags(self, tags: str, usn: Optional[int], clear_first: bool) -> bool:
-        if usn is None:
-            preserve_usn = False
-            usn_ = 0
-        else:
-            usn_ = usn
-            preserve_usn = True
-
-        return self._run_command(
-            pb.BackendInput(
-                register_tags=pb.RegisterTagsIn(
-                    tags=tags,
-                    usn=usn_,
-                    preserve_usn=preserve_usn,
-                    clear_first=clear_first,
-                )
-            )
-        ).register_tags
-
-    def get_changed_tags(self, usn: int) -> List[str]:
-        return list(
-            self._run_command(
-                pb.BackendInput(get_changed_tags=usn)
-            ).get_changed_tags.tags
+    def format_time_span(
+        self,
+        seconds: float,
+        context: FormatTimeSpanContext = FormatTimeSpanContext.INTERVALS,
+    ) -> str:
+        print(
+            "please use col.format_timespan() instead of col.backend.format_time_span()"
         )
+        return self.format_timespan(seconds, context)
 
-    def get_config_json(self, key: str) -> Any:
-        b = self._run_command(pb.BackendInput(get_config_json=key)).get_config_json
-        if b == b"":
-            raise KeyError
-        return orjson.loads(b)
-
-    def set_config_json(self, key: str, val: Any):
-        self._run_command(
-            pb.BackendInput(
-                set_config_json=pb.SetConfigJson(key=key, val=orjson.dumps(val))
-            )
-        )
-
-    def remove_config(self, key: str):
-        self._run_command(
-            pb.BackendInput(
-                set_config_json=pb.SetConfigJson(key=key, remove=pb.Empty())
-            )
-        )
-
-    def get_all_config(self) -> Dict[str, Any]:
-        jstr = self._run_command(
-            pb.BackendInput(get_all_config=pb.Empty())
-        ).get_all_config
-        return orjson.loads(jstr)
-
-    def set_all_config(self, conf: Dict[str, Any]):
-        self._run_command(pb.BackendInput(set_all_config=orjson.dumps(conf)))
-
-    def get_preferences(self) -> pb.Preferences:
-        return self._run_command(
-            pb.BackendInput(get_preferences=pb.Empty())
-        ).get_preferences
-
-    def set_preferences(self, prefs: pb.Preferences) -> None:
-        self._run_command(pb.BackendInput(set_preferences=prefs))
-
-    def _run_command2(self, method: int, input: Any) -> bytes:
+    def _run_command(self, method: int, input: Any) -> bytes:
         input_bytes = input.SerializeToString()
         try:
-            return self._backend.command2(method, input_bytes)
+            return self._backend.command(method, input_bytes)
         except Exception as e:
             err_bytes = bytes(e.args[0])
             err = pb.BackendError()
@@ -338,7 +256,7 @@ class RustBackend:
     def extract_av_tags(self, text: str, question_side: bool) -> pb.ExtractAVTagsOut:
         input = pb.ExtractAVTagsIn(text=text, question_side=question_side)
         output = pb.ExtractAVTagsOut()
-        output.ParseFromString(self._run_command2(1, input))
+        output.ParseFromString(self._run_command(1, input))
         return output
 
     def extract_latex(
@@ -346,19 +264,19 @@ class RustBackend:
     ) -> pb.ExtractLatexOut:
         input = pb.ExtractLatexIn(text=text, svg=svg, expand_clozes=expand_clozes)
         output = pb.ExtractLatexOut()
-        output.ParseFromString(self._run_command2(2, input))
+        output.ParseFromString(self._run_command(2, input))
         return output
 
     def get_empty_cards(self) -> pb.EmptyCardsReport:
         input = pb.Empty()
         output = pb.EmptyCardsReport()
-        output.ParseFromString(self._run_command2(3, input))
+        output.ParseFromString(self._run_command(3, input))
         return output
 
     def render_existing_card(self, card_id: int, browser: bool) -> pb.RenderCardOut:
         input = pb.RenderExistingCardIn(card_id=card_id, browser=browser)
         output = pb.RenderCardOut()
-        output.ParseFromString(self._run_command2(4, input))
+        output.ParseFromString(self._run_command(4, input))
         return output
 
     def render_uncommitted_card(
@@ -368,25 +286,25 @@ class RustBackend:
             note=note, card_ord=card_ord, template=template, fill_empty=fill_empty
         )
         output = pb.RenderCardOut()
-        output.ParseFromString(self._run_command2(5, input))
+        output.ParseFromString(self._run_command(5, input))
         return output
 
     def strip_av_tags(self, val: str) -> str:
         input = pb.String(val=val)
         output = pb.String()
-        output.ParseFromString(self._run_command2(6, input))
+        output.ParseFromString(self._run_command(6, input))
         return output.val
 
     def search_cards(self, search: str, order: pb.SortOrder) -> Sequence[int]:
         input = pb.SearchCardsIn(search=search, order=order)
         output = pb.SearchCardsOut()
-        output.ParseFromString(self._run_command2(7, input))
+        output.ParseFromString(self._run_command(7, input))
         return output.card_ids
 
     def search_notes(self, search: str) -> Sequence[int]:
         input = pb.SearchNotesIn(search=search)
         output = pb.SearchNotesOut()
-        output.ParseFromString(self._run_command2(8, input))
+        output.ParseFromString(self._run_command(8, input))
         return output.note_ids
 
     def find_and_replace(
@@ -407,67 +325,67 @@ class RustBackend:
             field_name=field_name,
         )
         output = pb.UInt32()
-        output.ParseFromString(self._run_command2(9, input))
+        output.ParseFromString(self._run_command(9, input))
         return output.val
 
     def local_minutes_west(self, val: int) -> int:
         input = pb.Int64(val=val)
         output = pb.Int32()
-        output.ParseFromString(self._run_command2(10, input))
+        output.ParseFromString(self._run_command(10, input))
         return output.val
 
     def set_local_minutes_west(self, val: int) -> pb.Empty:
         input = pb.Int32(val=val)
         output = pb.Empty()
-        output.ParseFromString(self._run_command2(11, input))
+        output.ParseFromString(self._run_command(11, input))
         return output
 
     def sched_timing_today(self) -> pb.SchedTimingTodayOut:
         input = pb.Empty()
         output = pb.SchedTimingTodayOut()
-        output.ParseFromString(self._run_command2(12, input))
+        output.ParseFromString(self._run_command(12, input))
         return output
 
     def studied_today(self, cards: int, seconds: float) -> str:
         input = pb.StudiedTodayIn(cards=cards, seconds=seconds)
         output = pb.String()
-        output.ParseFromString(self._run_command2(13, input))
+        output.ParseFromString(self._run_command(13, input))
         return output.val
 
     def congrats_learn_message(self, next_due: float, remaining: int) -> str:
         input = pb.CongratsLearnMessageIn(next_due=next_due, remaining=remaining)
         output = pb.String()
-        output.ParseFromString(self._run_command2(14, input))
+        output.ParseFromString(self._run_command(14, input))
         return output.val
 
     def check_media(self) -> pb.CheckMediaOut:
         input = pb.Empty()
         output = pb.CheckMediaOut()
-        output.ParseFromString(self._run_command2(15, input))
+        output.ParseFromString(self._run_command(15, input))
         return output
 
     def trash_media_files(self, fnames: Sequence[str]) -> pb.Empty:
         input = pb.TrashMediaFilesIn(fnames=fnames)
         output = pb.Empty()
-        output.ParseFromString(self._run_command2(16, input))
+        output.ParseFromString(self._run_command(16, input))
         return output
 
     def add_media_file(self, desired_name: str, data: bytes) -> str:
         input = pb.AddMediaFileIn(desired_name=desired_name, data=data)
         output = pb.String()
-        output.ParseFromString(self._run_command2(17, input))
+        output.ParseFromString(self._run_command(17, input))
         return output.val
 
     def empty_trash(self) -> pb.Empty:
         input = pb.Empty()
         output = pb.Empty()
-        output.ParseFromString(self._run_command2(18, input))
+        output.ParseFromString(self._run_command(18, input))
         return output
 
     def restore_trash(self) -> pb.Empty:
         input = pb.Empty()
         output = pb.Empty()
-        output.ParseFromString(self._run_command2(19, input))
+        output.ParseFromString(self._run_command(19, input))
         return output
 
     def add_or_update_deck_legacy(
@@ -477,37 +395,37 @@ class RustBackend:
             deck=deck, preserve_usn_and_mtime=preserve_usn_and_mtime
         )
         output = pb.DeckID()
-        output.ParseFromString(self._run_command2(20, input))
+        output.ParseFromString(self._run_command(20, input))
         return output.did
 
     def deck_tree(self, include_counts: bool, top_deck_id: int) -> pb.DeckTreeNode:
         input = pb.DeckTreeIn(include_counts=include_counts, top_deck_id=top_deck_id)
         output = pb.DeckTreeNode()
-        output.ParseFromString(self._run_command2(21, input))
+        output.ParseFromString(self._run_command(21, input))
         return output
 
     def deck_tree_legacy(self) -> bytes:
         input = pb.Empty()
         output = pb.Json()
-        output.ParseFromString(self._run_command2(22, input))
+        output.ParseFromString(self._run_command(22, input))
         return output.json
 
     def get_all_decks_legacy(self) -> bytes:
         input = pb.Empty()
         output = pb.Json()
-        output.ParseFromString(self._run_command2(23, input))
+        output.ParseFromString(self._run_command(23, input))
         return output.json
 
     def get_deck_id_by_name(self, val: str) -> int:
         input = pb.String(val=val)
         output = pb.DeckID()
-        output.ParseFromString(self._run_command2(24, input))
+        output.ParseFromString(self._run_command(24, input))
         return output.did
 
     def get_deck_legacy(self, did: int) -> bytes:
         input = pb.DeckID(did=did)
         output = pb.Json()
-        output.ParseFromString(self._run_command2(25, input))
+        output.ParseFromString(self._run_command(25, input))
         return output.json
 
     def get_deck_names(
@@ -517,19 +435,19 @@ class RustBackend:
             skip_empty_default=skip_empty_default, include_filtered=include_filtered
         )
         output = pb.DeckNames()
-        output.ParseFromString(self._run_command2(26, input))
+        output.ParseFromString(self._run_command(26, input))
         return output.entries
 
     def new_deck_legacy(self, val: bool) -> bytes:
         input = pb.Bool(val=val)
         output = pb.Json()
-        output.ParseFromString(self._run_command2(27, input))
+        output.ParseFromString(self._run_command(27, input))
         return output.json
 
     def remove_deck(self, did: int) -> pb.Empty:
         input = pb.DeckID(did=did)
         output = pb.Empty()
-        output.ParseFromString(self._run_command2(28, input))
+        output.ParseFromString(self._run_command(28, input))
         return output
 
     def add_or_update_deck_config_legacy(
@@ -539,76 +457,76 @@ class RustBackend:
             config=config, preserve_usn_and_mtime=preserve_usn_and_mtime
         )
         output = pb.DeckConfigID()
-        output.ParseFromString(self._run_command2(29, input))
+        output.ParseFromString(self._run_command(29, input))
         return output.dcid
 
     def all_deck_config_legacy(self) -> bytes:
         input = pb.Empty()
         output = pb.Json()
-        output.ParseFromString(self._run_command2(30, input))
+        output.ParseFromString(self._run_command(30, input))
         return output.json
 
     def get_deck_config_legacy(self, dcid: int) -> bytes:
         input = pb.DeckConfigID(dcid=dcid)
         output = pb.Json()
-        output.ParseFromString(self._run_command2(31, input))
+        output.ParseFromString(self._run_command(31, input))
         return output.json
 
     def new_deck_config_legacy(self) -> bytes:
         input = pb.Empty()
         output = pb.Json()
-        output.ParseFromString(self._run_command2(32, input))
+        output.ParseFromString(self._run_command(32, input))
         return output.json
 
     def remove_deck_config(self, dcid: int) -> pb.Empty:
         input = pb.DeckConfigID(dcid=dcid)
         output = pb.Empty()
-        output.ParseFromString(self._run_command2(33, input))
+        output.ParseFromString(self._run_command(33, input))
         return output
 
     def get_card(self, cid: int) -> pb.Card:
         input = pb.CardID(cid=cid)
         output = pb.Card()
-        output.ParseFromString(self._run_command2(34, input))
+        output.ParseFromString(self._run_command(34, input))
         return output
 
     def update_card(self, input: pb.Card) -> pb.Empty:
         output = pb.Empty()
-        output.ParseFromString(self._run_command2(35, input))
+        output.ParseFromString(self._run_command(35, input))
         return output
 
     def add_card(self, input: pb.Card) -> int:
         output = pb.CardID()
-        output.ParseFromString(self._run_command2(36, input))
+        output.ParseFromString(self._run_command(36, input))
         return output.cid
 
     def new_note(self, ntid: int) -> pb.Note:
         input = pb.NoteTypeID(ntid=ntid)
         output = pb.Note()
-        output.ParseFromString(self._run_command2(37, input))
+        output.ParseFromString(self._run_command(37, input))
         return output
 
     def add_note(self, note: pb.Note, deck_id: int) -> int:
         input = pb.AddNoteIn(note=note, deck_id=deck_id)
         output = pb.NoteID()
-        output.ParseFromString(self._run_command2(38, input))
+        output.ParseFromString(self._run_command(38, input))
         return output.nid
 
     def update_note(self, input: pb.Note) -> pb.Empty:
         output = pb.Empty()
-        output.ParseFromString(self._run_command2(39, input))
+        output.ParseFromString(self._run_command(39, input))
         return output
 
     def get_note(self, nid: int) -> pb.Note:
         input = pb.NoteID(nid=nid)
         output = pb.Note()
-        output.ParseFromString(self._run_command2(40, input))
+        output.ParseFromString(self._run_command(40, input))
         return output
 
     def add_note_tags(self, nids: Sequence[int], tags: str) -> int:
         input = pb.AddNoteTagsIn(nids=nids, tags=tags)
         output = pb.UInt32()
-        output.ParseFromString(self._run_command2(41, input))
+        output.ParseFromString(self._run_command(41, input))
         return output.val
 
     def update_note_tags(
@@ -618,12 +536,12 @@ class RustBackend:
             nids=nids, tags=tags, replacement=replacement, regex=regex
         )
         output = pb.UInt32()
-        output.ParseFromString(self._run_command2(42, input))
+        output.ParseFromString(self._run_command(42, input))
         return output.val
 
     def cloze_numbers_in_note(self, input: pb.Note) -> Sequence[int]:
         output = pb.ClozeNumbersInNoteOut()
-        output.ParseFromString(self._run_command2(43, input))
+        output.ParseFromString(self._run_command(43, input))
         return output.numbers
 
     def after_note_updates(
@@ -635,13 +553,13 @@ class RustBackend:
             generate_cards=generate_cards,
         )
         output = pb.Empty()
-        output.ParseFromString(self._run_command2(44, input))
+        output.ParseFromString(self._run_command(44, input))
         return output
 
     def field_names_for_notes(self, nids: Sequence[int]) -> Sequence[str]:
         input = pb.FieldNamesForNotesIn(nids=nids)
         output = pb.FieldNamesForNotesOut()
-        output.ParseFromString(self._run_command2(45, input))
+        output.ParseFromString(self._run_command(45, input))
         return output.fields
 
     def add_or_update_notetype(self, json: bytes, preserve_usn_and_mtime: bool) -> int:
@@ -649,43 +567,43 @@ class RustBackend:
             json=json, preserve_usn_and_mtime=preserve_usn_and_mtime
         )
         output = pb.NoteTypeID()
-        output.ParseFromString(self._run_command2(46, input))
+        output.ParseFromString(self._run_command(46, input))
         return output.ntid
 
     def get_stock_notetype_legacy(self, kind: pb.StockNoteType) -> bytes:
         input = pb.GetStockNotetypeIn(kind=kind)
         output = pb.Json()
-        output.ParseFromString(self._run_command2(47, input))
+        output.ParseFromString(self._run_command(47, input))
         return output.json
 
     def get_notetype_legacy(self, ntid: int) -> bytes:
         input = pb.NoteTypeID(ntid=ntid)
         output = pb.Json()
-        output.ParseFromString(self._run_command2(48, input))
+        output.ParseFromString(self._run_command(48, input))
         return output.json
 
     def get_notetype_names(self) -> Sequence[pb.NoteTypeNameID]:
         input = pb.Empty()
         output = pb.NoteTypeNames()
-        output.ParseFromString(self._run_command2(49, input))
+        output.ParseFromString(self._run_command(49, input))
         return output.entries
 
     def get_notetype_names_and_counts(self) -> Sequence[pb.NoteTypeNameIDUseCount]:
         input = pb.Empty()
         output = pb.NoteTypeUseCounts()
-        output.ParseFromString(self._run_command2(50, input))
+        output.ParseFromString(self._run_command(50, input))
         return output.entries
 
     def get_notetype_id_by_name(self, val: str) -> int:
         input = pb.String(val=val)
         output = pb.NoteTypeID()
-        output.ParseFromString(self._run_command2(51, input))
+        output.ParseFromString(self._run_command(51, input))
         return output.ntid
 
     def remove_notetype(self, ntid: int) -> pb.Empty:
         input = pb.NoteTypeID(ntid=ntid)
         output = pb.Empty()
-        output.ParseFromString(self._run_command2(52, input))
+        output.ParseFromString(self._run_command(52, input))
         return output
 
     def open_collection(
@@ -702,37 +620,114 @@ class RustBackend:
             log_path=log_path,
         )
         output = pb.Empty()
-        output.ParseFromString(self._run_command2(53, input))
+        output.ParseFromString(self._run_command(53, input))
         return output
 
     def close_collection(self, downgrade_to_schema11: bool) -> pb.Empty:
         input = pb.CloseCollectionIn(downgrade_to_schema11=downgrade_to_schema11)
         output = pb.Empty()
-        output.ParseFromString(self._run_command2(54, input))
+        output.ParseFromString(self._run_command(54, input))
         return output
 
     def check_database(self) -> Sequence[str]:
         input = pb.Empty()
         output = pb.CheckDatabaseOut()
-        output.ParseFromString(self._run_command2(55, input))
+        output.ParseFromString(self._run_command(55, input))
         return output.problems
 
     def sync_media(self, hkey: str, endpoint: str) -> pb.Empty:
         input = pb.SyncMediaIn(hkey=hkey, endpoint=endpoint)
         output = pb.Empty()
-        output.ParseFromString(self._run_command2(56, input))
+        output.ParseFromString(self._run_command(56, input))
         return output
 
     def abort_media_sync(self) -> pb.Empty:
         input = pb.Empty()
         output = pb.Empty()
-        output.ParseFromString(self._run_command2(57, input))
+        output.ParseFromString(self._run_command(57, input))
         return output
 
     def before_upload(self) -> pb.Empty:
         input = pb.Empty()
         output = pb.Empty()
-        output.ParseFromString(self._run_command2(58, input))
+        output.ParseFromString(self._run_command(58, input))
+        return output
+
+    def translate_string(self, input: pb.TranslateStringIn) -> str:
+        output = pb.String()
+        output.ParseFromString(self._run_command(59, input))
+        return output.val
+
+    def format_timespan(
+        self, seconds: float, context: pb.FormatTimespanIn.Context
+    ) -> str:
+        input = pb.FormatTimespanIn(seconds=seconds, context=context)
+        output = pb.String()
+        output.ParseFromString(self._run_command(60, input))
+        return output.val
+
+    def register_tags(
+        self, tags: str, preserve_usn: bool, usn: int, clear_first: bool
+    ) -> bool:
+        input = pb.RegisterTagsIn(
+            tags=tags, preserve_usn=preserve_usn, usn=usn, clear_first=clear_first
+        )
+        output = pb.Bool()
+        output.ParseFromString(self._run_command(61, input))
+        return output.val
+
+    def all_tags(self) -> Sequence[pb.TagUsnTuple]:
+        input = pb.Empty()
+        output = pb.AllTagsOut()
+        output.ParseFromString(self._run_command(62, input))
+        return output.tags
+
+    def get_changed_tags(self, val: int) -> Sequence[str]:
+        input = pb.Int32(val=val)
+        output = pb.GetChangedTagsOut()
+        output.ParseFromString(self._run_command(63, input))
+        return output.tags
+
+    def get_config_json(self, val: str) -> bytes:
+        input = pb.String(val=val)
+        output = pb.Json()
+        output.ParseFromString(self._run_command(64, input))
+        return output.json
+
+    def set_config_json(self, key: str, val: bytes) -> pb.Empty:
+        input = pb.SetConfigJsonIn(key=key, val=val)
+        output = pb.Empty()
+        output.ParseFromString(self._run_command(65, input))
+        return output
+
+    def remove_config(self, val: str) -> pb.Empty:
+        input = pb.String(val=val)
+        output = pb.Empty()
+        output.ParseFromString(self._run_command(66, input))
+        return output
+
+    def set_all_config(self, json: bytes) -> pb.Empty:
+        input = pb.Json(json=json)
+        output = pb.Empty()
+        output.ParseFromString(self._run_command(67, input))
+        return output
+
+    def get_all_config(self) -> bytes:
+        input = pb.Empty()
+        output = pb.Json()
+        output.ParseFromString(self._run_command(68, input))
+        return output.json
+
+    def get_preferences(self) -> pb.CollectionSchedulingSettings:
+        input = pb.Empty()
+        output = pb.Preferences()
+        output.ParseFromString(self._run_command(69, input))
+        return output.sched
+
+    def set_preferences(self, sched: pb.CollectionSchedulingSettings) -> pb.Empty:
+        input = pb.Preferences(sched=sched)
+        output = pb.Empty()
+        output.ParseFromString(self._run_command(70, input))
         return output
 
     # @@AUTOGEN@@
diff --git a/pylib/anki/schedv2.py b/pylib/anki/schedv2.py
index 6c4c216d0..63ce56e13 100644
--- a/pylib/anki/schedv2.py
+++ b/pylib/anki/schedv2.py
@@ -1369,9 +1369,7 @@ To study outside of the normal schedule, click the Custom Study button below."""
         ivl_secs = self.nextIvl(card, ease)
         if not ivl_secs:
             return _("(end)")
-        s = self.col.backend.format_time_span(
-            ivl_secs, FormatTimeSpanContext.ANSWER_BUTTONS
-        )
+        s = self.col.format_timespan(ivl_secs, FormatTimeSpanContext.ANSWER_BUTTONS)
         if ivl_secs < self.col.conf["collapseTime"]:
             s = "<" + s
         return s
diff --git a/pylib/anki/stats.py b/pylib/anki/stats.py
index 2fc3363a0..d6e330854 100644
--- a/pylib/anki/stats.py
+++ b/pylib/anki/stats.py
@@ -52,9 +52,7 @@ class CardStats:
             if next:
                 self.addLine(self.col.tr(TR.STATISTICS_DUE_DATE), next)
             if c.queue == QUEUE_TYPE_REV:
-                self.addLine(
-                    _("Interval"), self.col.backend.format_time_span(c.ivl * 86400)
-                )
+                self.addLine(_("Interval"), self.col.format_timespan(c.ivl * 86400))
             self.addLine(_("Ease"), "%d%%" % (c.factor / 10.0))
             self.addLine(_("Reviews"), "%d" % c.reps)
             self.addLine(_("Lapses"), "%d" % c.lapses)
@@ -86,9 +84,7 @@ class CardStats:
         return time.strftime("%Y-%m-%d", time.localtime(tm))
 
     def time(self, tm: float) -> str:
-        return self.col.backend.format_time_span(
-            tm, context=FormatTimeSpanContext.PRECISE
-        )
+        return self.col.format_timespan(tm, context=FormatTimeSpanContext.PRECISE)
 
 
 # Collection stats
@@ -645,12 +641,8 @@ group by day order by day)"""
             ),
         )
         i: List[str] = []
-        self._line(
-            i, _("Average interval"), self.col.backend.format_time_span(avg * 86400)
-        )
-        self._line(
-            i, _("Longest interval"), self.col.backend.format_time_span(max_ * 86400)
-        )
+        self._line(i, _("Average interval"), self.col.format_timespan(avg * 86400))
+        self._line(i, _("Longest interval"), self.col.format_timespan(max_ * 86400))
         return txt + self._lineTbl(i)
 
     def _ivls(self) -> Tuple[List[Any], int]:
diff --git a/pylib/anki/sync.py b/pylib/anki/sync.py
index 8182d8468..8d925802e 100644
--- a/pylib/anki/sync.py
+++ b/pylib/anki/sync.py
@@ -19,6 +19,8 @@ from . import hooks
 from .httpclient import HttpClient
 
 # add-on compat
+from .rsbackend import from_json_bytes, to_json_bytes
+
 AnkiRequestsClient = HttpClient
 
 
@@ -402,7 +404,7 @@ from notes where %s"""
     ##########################################################################
 
     def getTags(self) -> List:
-        return self.col.backend.get_changed_tags(self.maxUsn)
+        return list(self.col.backend.get_changed_tags(self.maxUsn))
 
     def mergeTags(self, tags) -> None:
         self.col.tags.register(tags, usn=self.maxUsn)
@@ -448,10 +450,10 @@ from notes where %s"""
     ##########################################################################
 
     def getConf(self) -> Dict[str, Any]:
-        return self.col.backend.get_all_config()
+        return from_json_bytes(self.col.backend.get_all_config())
 
     def mergeConf(self, conf: Dict[str, Any]) -> None:
-        self.col.backend.set_all_config(conf)
+        self.col.backend.set_all_config(to_json_bytes(conf))
 
 
 # HTTP syncing tools
diff --git a/pylib/anki/tags.py b/pylib/anki/tags.py
index 7e27b4f81..c6aa7d910 100644
--- a/pylib/anki/tags.py
+++ b/pylib/anki/tags.py
@@ -36,7 +36,16 @@ class TagManager:
     def register(
         self, tags: Collection[str], usn: Optional[int] = None, clear=False
     ) -> None:
-        self.col.backend.register_tags(" ".join(tags), usn, clear)
+        if usn is None:
+            preserve_usn = False
+            usn_ = 0
+        else:
+            usn_ = usn
+            preserve_usn = True
+
+        self.col.backend.register_tags(
+            tags=" ".join(tags), preserve_usn=preserve_usn, usn=usn_, clear_first=clear
+        )
 
     def registerNotes(self, nids: Optional[List[int]] = None) -> None:
         "Add any missing tags from notes to the tags list."
diff --git a/pylib/tools/genbackend.py b/pylib/tools/genbackend.py
index 5c4dc7cb8..862595966 100755
--- a/pylib/tools/genbackend.py
+++ b/pylib/tools/genbackend.py
@@ -29,6 +29,9 @@ LABEL_OPTIONAL = 1
 LABEL_REQUIRED = 2
 LABEL_REPEATED = 3
 
+# messages we don't want to unroll in codegen
+SKIP_UNROLL_INPUT = {"TranslateString"}
+
 
 def python_type(field):
     type = python_type_inner(field)
@@ -50,13 +53,20 @@ def python_type_inner(field):
     elif type == TYPE_BYTES:
         return "bytes"
     elif type == TYPE_MESSAGE:
-        return "pb." + field.message_type.name
+        return fullname(field.message_type.full_name)
     elif type == TYPE_ENUM:
-        return "pb." + field.enum_type.name
+        return fullname(field.enum_type.full_name)
     else:
         raise Exception(f"unknown type: {type}")
 
 
+def fullname(fullname):
+    if "FluentString" in fullname:
+        return fullname.replace("backend_proto", "anki.fluent_pb2")
+    else:
+        return fullname.replace("backend_proto", "pb")
+
+
 # get_deck_i_d -> get_deck_id etc
 def fix_snakecase(name):
     for fix in "a_v", "i_d":
@@ -80,14 +90,18 @@ def get_input_assign(msg):
 
 def render_method(method, idx):
     input_name = method.input_type.name
-    if input_name.endswith("In") or len(method.input_type.fields) < 2:
+    if (
+        (input_name.endswith("In") or len(method.input_type.fields) < 2)
+        and not method.input_type.oneofs
+        and not method.name in SKIP_UNROLL_INPUT
+    ):
         input_args = get_input_args(method.input_type)
         input_assign = get_input_assign(method.input_type)
         input_assign_outer = (
-            f"input = pb.{method.input_type.name}({input_assign})\n        "
+            f"input = {fullname(method.input_type.full_name)}({input_assign})\n        "
         )
     else:
-        input_args = f"self, input: pb.{input_name}"
+        input_args = f"self, input: {fullname(method.input_type.full_name)}"
         input_assign_outer = ""
     name = fix_snakecase(stringcase.snakecase(method.name))
     if len(method.output_type.fields) == 1:
@@ -101,7 +115,7 @@ def render_method(method, idx):
     return f"""\
     def {name}({input_args}) -> {return_type}:
         {input_assign_outer}output = pb.{method.output_type.name}()
-        output.ParseFromString(self._run_command2({idx+1}, input))
+        output.ParseFromString(self._run_command({idx+1}, input))
         return output{single_field}
 """
 
diff --git a/qt/aqt/browser.py b/qt/aqt/browser.py
index f10e59d7e..3ee8623f6 100644
--- a/qt/aqt/browser.py
+++ b/qt/aqt/browser.py
@@ -323,7 +323,7 @@ class DataModel(QAbstractTableModel):
                 return _("(new)")
             elif c.type == CARD_TYPE_LRN:
                 return _("(learning)")
-            return self.col.backend.format_time_span(c.ivl * 86400)
+            return self.col.format_timespan(c.ivl * 86400)
         elif type == "cardEase":
             if c.type == CARD_TYPE_NEW:
                 return _("(new)")
@@ -1491,7 +1491,7 @@ border: 1px solid #000; padding: 3px; '>%s</div>"""
 
             s += ("<td align=right>%s</td>" * 2) % (
                 "%d%%" % (factor / 10) if factor else "",
-                self.col.backend.format_time_span(taken),
+                self.col.format_timespan(taken),
             ) + "</tr>"
         s += "</table>"
         if cnt < self.card.reps:
diff --git a/qt/aqt/legacy.py b/qt/aqt/legacy.py
index 828025a58..96d458079 100644
--- a/qt/aqt/legacy.py
+++ b/qt/aqt/legacy.py
@@ -40,7 +40,7 @@ def stripSounds(text) -> str:
 
 def fmtTimeSpan(time, pad=0, point=0, short=False, inTime=False, unit=99):
     print("fmtTimeSpan() has become col.backend.format_time_span()")
-    return aqt.mw.col.backend.format_time_span(time)
+    return aqt.mw.col.format_timespan(time)
 
 
 def install_pylib_legacy() -> None:
diff --git a/rslib/src/backend/mod.rs b/rslib/src/backend/mod.rs
index 2fb769b26..29705c034 100644
--- a/rslib/src/backend/mod.rs
+++ b/rslib/src/backend/mod.rs
@@ -41,7 +41,7 @@ use crate::{
 use fluent::FluentValue;
 use futures::future::{AbortHandle, Abortable};
 use log::error;
-use pb::{backend_input::Value, BackendService};
+use pb::BackendService;
 use prost::Message;
 use serde_json::Value as JsonValue;
 use std::collections::{HashMap, HashSet};
@@ -99,13 +99,6 @@ fn anki_error_to_proto_error(err: AnkiError, i18n: &I18n) -> pb::BackendError {
     }
 }
 
-// Convert an Anki error to a protobuf output.
-impl std::convert::From<pb::BackendError> for pb::backend_output::Value {
-    fn from(err: pb::BackendError) -> Self {
-        pb::backend_output::Value::Error(err)
-    }
-}
-
 impl std::convert::From<NetworkErrorKind> for i32 {
     fn from(e: NetworkErrorKind) -> Self {
         use pb::network_error::NetworkErrorKind as V;
@@ -947,6 +940,133 @@ impl BackendService for Backend {
     fn before_upload(&mut self, _input: Empty) -> BackendResult<Empty> {
         self.with_col(|col| col.before_upload().map(Into::into))
     }
+
+    // i18n/messages
+    //-------------------------------------------------------------------
+
+    fn translate_string(&mut self, input: pb::TranslateStringIn) -> BackendResult<pb::String> {
+        let key = match pb::FluentString::from_i32(input.key) {
+            Some(key) => key,
+            None => return Ok("invalid key".to_string().into()),
+        };
+
+        let map = input
+            .args
+            .iter()
+            .map(|(k, v)| (k.as_str(), translate_arg_to_fluent_val(&v)))
+            .collect();
+
+        Ok(self.i18n.trn(key, map).into())
+    }
+
+    fn format_timespan(&mut self, input: pb::FormatTimespanIn) -> BackendResult<pb::String> {
+        let context = match pb::format_timespan_in::Context::from_i32(input.context) {
+            Some(context) => context,
+            None => return Ok("".to_string().into()),
+        };
+        Ok(match context {
+            pb::format_timespan_in::Context::Precise => time_span(input.seconds, &self.i18n, true),
+            pb::format_timespan_in::Context::Intervals => {
+                time_span(input.seconds, &self.i18n, false)
+            }
+            pb::format_timespan_in::Context::AnswerButtons => {
+                answer_button_time(input.seconds, &self.i18n)
+            }
+        }
+        .into())
+    }
+
+    // tags
+    //-------------------------------------------------------------------
+
+    fn all_tags(&mut self, _input: Empty) -> BackendResult<pb::AllTagsOut> {
+        let tags = self.with_col(|col| col.storage.all_tags())?;
+        let tags: Vec<_> = tags
+            .into_iter()
+            .map(|(tag, usn)| pb::TagUsnTuple { tag, usn: usn.0 })
+            .collect();
+        Ok(pb::AllTagsOut { tags })
+    }
+
+    fn register_tags(&mut self, input: pb::RegisterTagsIn) -> BackendResult<pb::Bool> {
+        self.with_col(|col| {
+            col.transact(None, |col| {
+                let usn = if input.preserve_usn {
+                    Usn(input.usn)
+                } else {
+                    col.usn()?
+                };
+                col.register_tags(&input.tags, usn, input.clear_first)
+                    .map(|val| pb::Bool { val })
+            })
+        })
+    }
+
+    fn get_changed_tags(&mut self, input: pb::Int32) -> BackendResult<pb::GetChangedTagsOut> {
+        self.with_col(|col| {
+            col.transact(None, |col| {
+                Ok(pb::GetChangedTagsOut {
+                    tags: col.storage.get_changed_tags(Usn(input.val))?,
+                })
+            })
+        })
+    }
+
+    // config/preferences
+    //-------------------------------------------------------------------
+
+    fn get_config_json(&mut self, input: pb::String) -> BackendResult<pb::Json> {
+        self.with_col(|col| {
+            let val: Option<JsonValue> = col.get_config_optional(input.val.as_str());
+            val.ok_or(AnkiError::NotFound)
+                .and_then(|v| serde_json::to_vec(&v).map_err(Into::into))
+                .map(Into::into)
+        })
+    }
+
+    fn set_config_json(&mut self, input: pb::SetConfigJsonIn) -> BackendResult<Empty> {
+        self.with_col(|col| {
+            col.transact(None, |col| {
+                // ensure it's a well-formed object
+                let val: JsonValue = serde_json::from_slice(&input.val)?;
+                col.set_config(input.key.as_str(), &val)
+            })
+        })
+        .map(Into::into)
+    }
+
+    fn remove_config(&mut self, input: pb::String) -> BackendResult<Empty> {
+        self.with_col(|col| col.transact(None, |col| col.remove_config(input.val.as_str())))
+            .map(Into::into)
+    }
+
+    fn set_all_config(&mut self, input: pb::Json) -> BackendResult<Empty> {
+        let val: HashMap<String, JsonValue> = serde_json::from_slice(&input.json)?;
+        self.with_col(|col| {
+            col.transact(None, |col| {
+                col.storage
+                    .set_all_config(val, col.usn()?, TimestampSecs::now())
+            })
+        })
+        .map(Into::into)
+    }
+
+    fn get_all_config(&mut self, _input: Empty) -> BackendResult<pb::Json> {
+        self.with_col(|col| {
+            let conf = col.storage.get_all_config()?;
+            serde_json::to_vec(&conf).map_err(Into::into)
+        })
+        .map(Into::into)
+    }
+
+    fn get_preferences(&mut self, _input: Empty) -> BackendResult<pb::Preferences> {
+        self.with_col(|col| col.get_preferences())
+    }
+
+    fn set_preferences(&mut self, input: pb::Preferences) -> BackendResult<Empty> {
+        self.with_col(|col| col.transact(None, |col| col.set_preferences(input)))
+            .map(Into::into)
+    }
 }
 
 impl Backend {
@@ -964,30 +1084,7 @@ impl Backend {
         &self.i18n
     }
 
-    /// Decode a request, process it, and return the encoded result.
-    pub fn run_command_bytes(&mut self, req: &[u8]) -> Vec<u8> {
-        let mut buf = vec![];
-
-        let req = match pb::BackendInput::decode(req) {
-            Ok(req) => req,
-            Err(_e) => {
-                // unable to decode
-                let err = AnkiError::invalid_input("couldn't decode backend request");
-                let oerr = anki_error_to_proto_error(err, &self.i18n);
-                let output = pb::BackendOutput {
-                    value: Some(oerr.into()),
-                };
-                output.encode(&mut buf).expect("encode failed");
-                return buf;
-            }
-        };
-
-        let resp = self.run_command(req);
-        resp.encode(&mut buf).expect("encode failed");
-        buf
-    }
-
-    pub fn run_command_bytes2(
+    pub fn run_command_bytes(
         &mut self,
         method: u32,
         input: &[u8],
@@ -1016,53 +1113,6 @@ impl Backend {
         )
     }
 
-    fn run_command(&mut self, input: pb::BackendInput) -> pb::BackendOutput {
-        let oval = if let Some(ival) = input.value {
-            match self.run_command_inner(ival) {
-                Ok(output) => output,
-                Err(err) => anki_error_to_proto_error(err, &self.i18n).into(),
-            }
-        } else {
-            anki_error_to_proto_error(
-                AnkiError::invalid_input("unrecognized backend input value"),
-                &self.i18n,
-            )
-            .into()
-        };
-
-        pb::BackendOutput { value: Some(oval) }
-    }
-
-    fn run_command_inner(
-        &mut self,
-        ival: pb::backend_input::Value,
-    ) -> Result<pb::backend_output::Value> {
-        use pb::backend_output::Value as OValue;
-        Ok(match ival {
-            Value::TranslateString(input) => OValue::TranslateString(self.translate_string(input)),
-            Value::FormatTimeSpan(input) => OValue::FormatTimeSpan(self.format_time_span(input)),
-            Value::AllTags(_) => OValue::AllTags(self.all_tags()?),
-            Value::RegisterTags(input) => OValue::RegisterTags(self.register_tags(input)?),
-            Value::GetChangedTags(usn) => OValue::GetChangedTags(self.get_changed_tags(usn)?),
-            Value::GetConfigJson(key) => OValue::GetConfigJson(self.get_config_json(&key)?),
-            Value::SetConfigJson(input) => OValue::SetConfigJson({
-                self.set_config_json(input)?;
-                pb::Empty {}
-            }),
-
-            Value::SetAllConfig(input) => OValue::SetConfigJson({
-                self.set_all_config(&input)?;
-                pb::Empty {}
-            }),
-            Value::GetAllConfig(_) => OValue::GetAllConfig(self.get_all_config()?),
-            Value::GetPreferences(_) => OValue::GetPreferences(self.get_preferences()?),
-            Value::SetPreferences(prefs) => OValue::SetPreferences({
-                self.set_preferences(prefs)?;
-                pb::Empty {}
-            }),
-        })
-    }
-
     fn fire_progress_callback(&self, progress: Progress) -> bool {
         if let Some(cb) = &self.progress_callback {
             let bytes = progress_to_proto_bytes(progress, &self.i18n);
@@ -1105,126 +1155,9 @@ impl Backend {
         ret
     }
 
-    fn translate_string(&self, input: pb::TranslateStringIn) -> String {
-        let key = match pb::FluentString::from_i32(input.key) {
-            Some(key) => key,
-            None => return "invalid key".to_string(),
-        };
-
-        let map = input
-            .args
-            .iter()
-            .map(|(k, v)| (k.as_str(), translate_arg_to_fluent_val(&v)))
-            .collect();
-
-        self.i18n.trn(key, map)
-    }
-
-    fn format_time_span(&self, input: pb::FormatTimeSpanIn) -> String {
-        let context = match pb::format_time_span_in::Context::from_i32(input.context) {
-            Some(context) => context,
-            None => return "".to_string(),
-        };
-        match context {
-            pb::format_time_span_in::Context::Precise => time_span(input.seconds, &self.i18n, true),
-            pb::format_time_span_in::Context::Intervals => {
-                time_span(input.seconds, &self.i18n, false)
-            }
-            pb::format_time_span_in::Context::AnswerButtons => {
-                answer_button_time(input.seconds, &self.i18n)
-            }
-        }
-    }
-
     pub fn db_command(&self, input: &[u8]) -> Result<String> {
         self.with_col(|col| db_command_bytes(&col.storage, input))
     }
-
-    fn all_tags(&self) -> Result<pb::AllTagsOut> {
-        let tags = self.with_col(|col| col.storage.all_tags())?;
-        let tags: Vec<_> = tags
-            .into_iter()
-            .map(|(tag, usn)| pb::TagUsnTuple { tag, usn: usn.0 })
-            .collect();
-        Ok(pb::AllTagsOut { tags })
-    }
-
-    fn register_tags(&self, input: pb::RegisterTagsIn) -> Result<bool> {
-        self.with_col(|col| {
-            col.transact(None, |col| {
-                let usn = if input.preserve_usn {
-                    Usn(input.usn)
-                } else {
-                    col.usn()?
-                };
-                col.register_tags(&input.tags, usn, input.clear_first)
-            })
-        })
-    }
-
-    fn get_changed_tags(&self, usn: i32) -> Result<pb::GetChangedTagsOut> {
-        self.with_col(|col| {
-            col.transact(None, |col| {
-                Ok(pb::GetChangedTagsOut {
-                    tags: col.storage.get_changed_tags(Usn(usn))?,
-                })
-            })
-        })
-    }
-
-    fn get_config_json(&self, key: &str) -> Result<Vec<u8>> {
-        self.with_col(|col| {
-            let val: Option<JsonValue> = col.get_config_optional(key);
-            match val {
-                None => Ok(vec![]),
-                Some(val) => Ok(serde_json::to_vec(&val)?),
-            }
-        })
-    }
-
-    fn set_config_json(&self, input: pb::SetConfigJson) -> Result<()> {
-        self.with_col(|col| {
-            col.transact(None, |col| {
-                if let Some(op) = input.op {
-                    match op {
-                        pb::set_config_json::Op::Val(val) => {
-                            // ensure it's a well-formed object
-                            let val: JsonValue = serde_json::from_slice(&val)?;
-                            col.set_config(input.key.as_str(), &val)
-                        }
-                        pb::set_config_json::Op::Remove(_) => col.remove_config(input.key.as_str()),
-                    }
-                } else {
-                    Err(AnkiError::invalid_input("no op received"))
-                }
-            })
-        })
-    }
-
-    fn set_all_config(&self, conf: &[u8]) -> Result<()> {
-        let val: HashMap<String, JsonValue> = serde_json::from_slice(conf)?;
-        self.with_col(|col| {
-            col.transact(None, |col| {
-                col.storage
-                    .set_all_config(val, col.usn()?, TimestampSecs::now())
-            })
-        })
-    }
-
-    fn get_all_config(&self) -> Result<Vec<u8>> {
-        self.with_col(|col| {
-            let conf = col.storage.get_all_config()?;
-            serde_json::to_vec(&conf).map_err(Into::into)
-        })
-    }
-
-    fn get_preferences(&self) -> Result<pb::Preferences> {
-        self.with_col(|col| col.get_preferences())
-    }
-
-    fn set_preferences(&self, prefs: pb::Preferences) -> Result<()> {
-        self.with_col(|col| col.transact(None, |col| col.set_preferences(prefs)))
-    }
 }
 
 fn to_nids(ids: Vec<i64>) -> Vec<NoteID> {
diff --git a/rspy/src/lib.rs b/rspy/src/lib.rs
index beac28fc2..b7fd82ad2 100644
--- a/rspy/src/lib.rs
+++ b/rspy/src/lib.rs
@@ -93,6 +93,18 @@ fn want_release_gil(method: u32) -> bool {
             BackendMethod::CloseCollection => true,
             BackendMethod::AbortMediaSync => true,
             BackendMethod::BeforeUpload => true,
+            BackendMethod::TranslateString => false,
+            BackendMethod::FormatTimespan => false,
+            BackendMethod::RegisterTags => true,
+            BackendMethod::AllTags => true,
+            BackendMethod::GetChangedTags => true,
+            BackendMethod::GetConfigJson => true,
+            BackendMethod::SetConfigJson => true,
+            BackendMethod::RemoveConfig => true,
+            BackendMethod::SetAllConfig => true,
+            BackendMethod::GetAllConfig => true,
+            BackendMethod::GetPreferences => true,
+            BackendMethod::SetPreferences => true,
         }
     } else {
         false
@@ -101,23 +113,12 @@ fn want_release_gil(method: u32) -> bool {
 
 #[pymethods]
 impl Backend {
-    fn command(&mut self, py: Python, input: &PyBytes, release_gil: bool) -> PyObject {
-        let in_bytes = input.as_bytes();
-        let out_bytes = if release_gil {
-            py.allow_threads(move || self.backend.run_command_bytes(in_bytes))
-        } else {
-            self.backend.run_command_bytes(in_bytes)
-        };
-        let out_obj = PyBytes::new(py, &out_bytes);
-        out_obj.into()
-    }
-
-    fn command2(&mut self, py: Python, method: u32, input: &PyBytes) -> PyResult<PyObject> {
+    fn command(&mut self, py: Python, method: u32, input: &PyBytes) -> PyResult<PyObject> {
         let in_bytes = input.as_bytes();
         if want_release_gil(method) {
-            py.allow_threads(move || self.backend.run_command_bytes2(method, in_bytes))
+            py.allow_threads(move || self.backend.run_command_bytes(method, in_bytes))
         } else {
-            self.backend.run_command_bytes2(method, in_bytes)
+            self.backend.run_command_bytes(method, in_bytes)
         }
         .map(|out_bytes| {
             let out_obj = PyBytes::new(py, &out_bytes);