From 2b1cf209d662f61fbafdcb623c94f55ae2e23834 Mon Sep 17 00:00:00 2001
From: WildAi <2853742+wildminder@users.noreply.github.com>
Date: Wed, 7 Oct 2026 13:22:03 +0300
Subject: [PATCH] feat(loader): dedupe shared weights across packs

- ve/s3gen/s3gen_v3 safetensors + grapheme tokenizer are byte-identical
  across every repo that ships them (sha256-verified): fetched at most
  once into a reserved _shared store, hardlinked into each pack
- downloads carry pack-unique files only (allow_patterns); legacy
  full-repo folders satisfy the store before anything is fetched
- vendored MTL loads ve/s3gen from either serialization, safetensors
  first; upstream's strict load refused every SLP pack (P-036)
- .pt twins (s3gen.pt, s3gen_v3.pt, t3_cfg.pt, ve.pt) are never fetched
---
 README.md                      |  39 ++++++-
 modules/loader.py              | 186 +++++++++++++++++++++++-------
 modules/model_discovery.py     |   7 +-
 modules/model_info.py          |  59 ++++++----
 src/PATCHES.md                 |   2 +-
 src/chatterbox/mtl_tts.py      |  65 ++++++++---
 tests/test_local_checkpoint.py |  18 ++-
 tests/test_patcher.py          |  11 +-
 tests/test_shared_assets.py    | 200 +++++++++++++++++++++++++++++++++
 tests/test_tts_routing.py      |   4 +-
 10 files changed, 498 insertions(+), 93 deletions(-)
 create mode 100644 tests/test_shared_assets.py

diff --git a/README.md b/README.md
index d54d214..cd7bbfa 100644
--- a/README.md
+++ b/README.md
@@ -230,14 +230,41 @@ downloaded:
 - **Single Language Packs** (the six `ResembleAI/Chatterbox-Multilingual-<lang>`
   finetunes) load through the **Chatterbox Multilingual TTS 🌍** node. Each
   ships its own per-language t3 checkpoint (`t3_zh_cmn`, `t3_es_mx_latam`,
-  `t3_es_es`, `t3_pt_br`, `t3_pt_pt`, `t3_hi`) plus the multilingual s3gen and
-  grapheme tokenizer, so the pack folder is self-describing — the pack decides
-  what loads, not the variant widget. Only zh-cmn ships a built-in voice
-  (`conds.pt`); the other five fetch the shared `ve.pt` from
-  `ResembleAI/chatterbox` on first load and **require a reference audio clip**.
-  The `language` widget is ignored — every pack speaks its own language.
+  `t3_es_es`, `t3_pt_br`, `t3_pt_pt`, `t3_hi`); the decoder, grapheme
+  tokenizer and voice encoder are byte-identical across all six and come from
+  the shared store instead of being downloaded six times (see below). Only
+  zh-cmn ships a built-in voice (`conds.pt`); the other five **require a
+  reference audio clip**. The `language` widget is ignored — every pack
+  speaks its own language.
 - Classic packs (`t3_cfg.safetensors`) are the voice-conversion packs too.
 
+#### How packs share files
+
+Four files are byte-identical across every repo that ships them (verified by
+sha256): `ve.safetensors`, `s3gen.safetensors`, `s3gen_v3.safetensors` and the
+grapheme tokenizer `grapheme_mtl_merged_expanded_v1.json`. The node therefore
+fetches each of them at most once, into a reserved store at
+
+```text
+ComfyUI/models/tts/chatterbox/_shared/
+```
+
+and hardlinks it into every pack that needs it — a hardlink costs no extra
+disk, and each pack folder stays self-contained. When one of these files
+already exists anywhere on disk (a full `chatterbox/` download from an older
+version counts), it is linked from there and nothing is fetched at all.
+
+A pack download consequently carries only its unique files: an extra Single
+Language Pack is its ~2 GB t3 checkpoint and nothing else. The one exception
+is Flash, whose `s3gen.safetensors` is a different decoder despite the shared
+name — it always downloads its own.
+
+Downloads never fetch the legacy `.pt` twins (`s3gen.pt`, `s3gen_v3.pt`,
+`t3_cfg.pt`, `ve.pt`): they hold the same weights as their `.safetensors`
+siblings and nothing loads them. Existing folders that carry the twins keep
+working — you can delete those four files from a full `chatterbox/` download
+to reclaim ~3 GB.
+
 Folders from earlier builds named like a pack plus a variant
 (`chatterbox-nano__turbo`) are ordinary packs as far as the scanner is
 concerned and keep loading; rename or delete them at will.
diff --git a/modules/loader.py b/modules/loader.py
index 388bbe1..e3623a3 100644
--- a/modules/loader.py
+++ b/modules/loader.py
@@ -33,16 +33,24 @@ from __future__ import annotations
 import inspect
 import logging
 import os
+import shutil
 from typing import Any, Optional
 
 import torch
 
-from .constants import DEFAULT_MODEL_PACK_NAME, MTL_T3_MODELS
+from .constants import (
+    CHATTERBOX_FILES_TO_DOWNLOAD,
+    DEFAULT_MODEL_PACK_NAME,
+    MTL_T3_MODELS,
+)
 from .model_discovery import get_model_pack_path
 from .model_info import (
     AVAILABLE_CHATTERBOX_MODELS,
     CHATTERBOX_WEIGHT_FILES,
     MODEL_CONFIGS,
+    MTL_TOKENIZER_FILE,
+    SHARED_ASSET_DIR_NAME,
+    SHARED_ASSET_FILES,
     is_chatterbox_model_dir,
 )
 
@@ -76,15 +84,24 @@ _WEIGHT_ATTRIBUTES = ("t3", "s3gen", "ve")
 # checkpoint is appended by the caller, because its name is not fixed -- and
 # so is the s3gen decoder's: the Single Language Packs ship ``s3gen_v3.pt``
 # (P-036), the shared repo ships ``s3gen.pt``.
-MTL_CHECKPOINT_FILES: tuple[str, ...] = (
-    "ve.pt",
-    "grapheme_mtl_merged_expanded_v1.json",
-)
+#: Files every multilingual pack holds *besides* the resolved T3, voice
+#: encoder and s3gen checkpoints (P-036 resolves those per pack): just the
+#: grapheme tokenizer.
+MTL_CHECKPOINT_FILES: tuple[str, ...] = (MTL_TOKENIZER_FILE,)
 
 #: The s3gen filenames a multilingual pack may carry, in resolution order:
-#: the shared repo's canonical name first, the Single Language Packs' v3
-#: retrain second.
-MTL_S3GEN_CHECKPOINTS: tuple[str, ...] = ("s3gen.pt", "s3gen_v3.pt")
+#: the Single Language Packs' v3 retrain (safetensors first), then the shared
+#: repo's canonical decoder.
+MTL_S3GEN_CHECKPOINTS: tuple[str, ...] = (
+    "s3gen_v3.safetensors",
+    "s3gen_v3.pt",
+    "s3gen.safetensors",
+    "s3gen.pt",
+)
+
+#: Pack folders that historically hold the shared repo's weights. Read-only
+#: search candidates for shared assets; downloads never write into them.
+LEGACY_SHARED_DIRS: tuple[str, ...] = ("chatterbox", DEFAULT_MODEL_PACK_NAME)
 
 #: Turbo and Nano share one layout, and so share one completeness list. The
 #: tokenizer is checked separately: Turbo ships ``tokenizer.json``, Nano ships
@@ -533,7 +550,12 @@ class ChatterboxLoader:
     # -- download ------------------------------------------------------
 
     @staticmethod
-    def _ensure_downloaded(repo_id: str, local_dir: str, model_name: str = "") -> None:
+    def _ensure_downloaded(
+        repo_id: str,
+        local_dir: str,
+        model_name: str = "",
+        allow_patterns: Optional[list[str]] = None,
+    ) -> None:
         """Fetch an official pack from ``repo_id`` when it is not on disk.
 
         The completeness check is :meth:`is_pack_complete` rather than a
@@ -566,6 +588,8 @@ class ChatterboxLoader:
         from huggingface_hub import snapshot_download
 
         kwargs: dict[str, Any] = {"repo_id": repo_id, "local_dir": local_dir}
+        if allow_patterns:
+            kwargs["allow_patterns"] = list(allow_patterns)
         try:
             accepts_symlinks = (
                 "local_dir_use_symlinks" in inspect.signature(snapshot_download).parameters
@@ -583,6 +607,7 @@ class ChatterboxLoader:
         repo_id: str,
         local_dir: str,
         client_id: Optional[str] = None,
+        allow_patterns: Optional[list[str]] = None,
     ) -> None:
         """Ensure the pack exists, preferring the progress-tracking manager.
 
@@ -591,12 +616,25 @@ class ChatterboxLoader:
         blocks the prompt with no way out. The manager is therefore the path
         taken, and :meth:`_ensure_downloaded` is the fallback for when it cannot
         be imported (or has been torn down).
+
+        ``allow_patterns`` narrows the fetch to the named files -- the shared
+        weights are deduplicated away (see ``SHARED_ASSET_FILES``), so a pack
+        download must not drag every byte of the repo along. The manager's API
+        has no patterns parameter, so a filtered fetch goes straight to
+        ``snapshot_download`` (which resumes and skips complete files); the
+        manager keeps serving the unfiltered legacy path.
         """
         if ChatterboxLoader.is_pack_complete(local_dir):
             return
         if not repo_id:
             return
 
+        if allow_patterns:
+            ChatterboxLoader._ensure_downloaded(
+                repo_id, local_dir, model_name, allow_patterns
+            )
+            return
+
         manager = None
         try:
             from .downloader import get_download_manager
@@ -675,7 +713,22 @@ class ChatterboxLoader:
                 model_name,
                 pack_dir,
             )
-            ChatterboxLoader.download_pack(model_name, repo_id, pack_dir, client_id)
+            files = list(entry.get("files") or CHATTERBOX_FILES_TO_DOWNLOAD)
+            unique = set(entry.get("unique_files") or ())
+            ChatterboxLoader.download_pack(
+                model_name,
+                repo_id,
+                pack_dir,
+                client_id,
+                allow_patterns=[
+                    name
+                    for name in files
+                    if name not in SHARED_ASSET_FILES or name in unique
+                ],
+            )
+            ChatterboxLoader._ensure_shared_assets(
+                pack_dir, [name for name in files if name in SHARED_ASSET_FILES]
+            )
             try:
                 os.makedirs(pack_dir, exist_ok=True)
             except OSError as exc:
@@ -734,6 +787,59 @@ class ChatterboxLoader:
         """
         return [name for name in required if not os.path.isfile(os.path.join(pack_dir, name))]
 
+    @staticmethod
+    def _shared_store_dir() -> str:
+        """The reserved ``_shared`` directory under the Chatterbox models root."""
+        from .model_discovery import get_models_root
+
+        return os.path.join(get_models_root(), SHARED_ASSET_DIR_NAME)
+
+    @staticmethod
+    def _ensure_shared_assets(pack_dir: str, names) -> None:
+        """Materialize shared weights into ``pack_dir`` under canonical names.
+
+        The shared files (``SHARED_ASSET_FILES``) are byte-identical across
+        every repo that ships them, so each is fetched at most once. Search
+        order: the pack itself (nothing to do), the reserved ``_shared``
+        store, then the legacy full-repo folders a user may already have;
+        only when the file exists nowhere does one ``hf_hub_download`` from
+        the shared Chatterbox repo populate the store. The store copy is then
+        hardlinked into the pack -- both live under the Chatterbox models
+        root, so they share a volume and the link costs no extra disk -- with
+        a plain copy as the fallback for exotic filesystems.
+        """
+        from huggingface_hub import hf_hub_download
+
+        from .constants import CHATTERBOX_REPO_ID
+
+        store = ChatterboxLoader._shared_store_dir()
+        root = os.path.dirname(store)
+        for name in names:
+            target = os.path.join(pack_dir, name)
+            if os.path.isfile(target):
+                continue
+            source = None
+            candidates = [store]
+            candidates.extend(os.path.join(root, d) for d in LEGACY_SHARED_DIRS)
+            for candidate in candidates:
+                probe = os.path.join(candidate, name)
+                if os.path.isfile(probe):
+                    source = probe
+                    break
+            if source is None:
+                os.makedirs(store, exist_ok=True)
+                source = hf_hub_download(
+                    repo_id=CHATTERBOX_REPO_ID, filename=name, local_dir=store
+                )
+            try:
+                os.link(source, target)
+            except OSError:
+                try:
+                    os.makedirs(pack_dir, exist_ok=True)
+                except OSError:
+                    pass
+                shutil.copyfile(source, target)
+
     @staticmethod
     def _ensure_entry_point_dir(
         pack_dir: str,
@@ -741,13 +847,12 @@ class ChatterboxLoader:
         required: tuple[str, ...],
         model_name: str,
         client_id: Optional[str] = None,
-        companion_files: Optional[dict[str, str]] = None,
     ) -> None:
         """Fetch ``repo_id`` into ``pack_dir`` when a required file is absent.
 
-        The shared prologue for the multilingual and Turbo entry points. Both
-        are ordinary Hugging Face snapshots with their own file layouts, so the
-        completeness test is ``required`` -- not
+        The shared prologue for the multilingual, Turbo and Flash entry
+        points. All are ordinary Hugging Face snapshots with their own file
+        layouts, so the completeness test is ``required`` -- not
         :meth:`is_pack_complete`, which is written for the *classic* layout and
         would therefore re-download a perfectly good multilingual pack on every
         run.
@@ -756,10 +861,12 @@ class ChatterboxLoader:
         drops under ``models/tts/chatterbox``) satisfy the same test and take the
         same path: there is no special case for them anywhere in this class.
 
-        ``companion_files`` maps a required file that lives in a *different*
-        repository to that repository's id -- the Single Language Packs carry
-        no ``ve.pt`` of their own; it is fetched per-file from the shared
-        Chatterbox repo (a ~17 MB voice encoder, no download manager needed).
+        Downloads are narrowed by the registry entry's ``files`` list minus
+        the shared assets (``SHARED_ASSET_FILES``) -- those are byte-identical
+        across the family and are materialized afterwards by
+        :meth:`_ensure_shared_assets`, hardlinked out of the ``_shared``
+        store. An entry-less (community) pack falls back to a whole-repo
+        fetch: its layout is unknown.
         """
         if os.path.isdir(pack_dir) and not ChatterboxLoader._missing_checkpoint_files(
             pack_dir, required
@@ -767,29 +874,29 @@ class ChatterboxLoader:
             return
         if not repo_id:
             return
+        entry = ChatterboxLoader._registry_entry(model_name) or {}
+        unique = set(entry.get("unique_files") or ())
+        shared_needed = [
+            name for name in required if name in SHARED_ASSET_FILES and name not in unique
+        ]
+        patterns = None
+        if entry.get("files"):
+            patterns = [
+                name
+                for name in entry["files"]
+                if name not in SHARED_ASSET_FILES or name in unique
+            ]
         logging.info(
             "[Chatterbox TTS] Fetching '%s' from %s into '%s'...",
             model_name,
             repo_id,
             pack_dir,
         )
-        ChatterboxLoader.download_pack(model_name, repo_id, pack_dir, client_id)
-        if companion_files:
-            from huggingface_hub import hf_hub_download
+        ChatterboxLoader.download_pack(
+            model_name, repo_id, pack_dir, client_id, allow_patterns=patterns
+        )
+        ChatterboxLoader._ensure_shared_assets(pack_dir, shared_needed)
 
-            for filename, companion_repo in companion_files.items():
-                if not companion_repo or os.path.isfile(os.path.join(pack_dir, filename)):
-                    continue
-                logging.info(
-                    "[Chatterbox TTS] Fetching companion file '%s' from %s...",
-                    filename,
-                    companion_repo,
-                )
-                hf_hub_download(
-                    repo_id=companion_repo, filename=filename, local_dir=pack_dir
-                )
-
-    @staticmethod
     @staticmethod
     def _registry_entry(model_name: str) -> Optional[dict]:
         """The registry config for ``model_name``, official or local, or ``None``."""
@@ -835,10 +942,10 @@ class ChatterboxLoader:
         """The s3gen decoder filename a multilingual pack actually holds.
 
         The directory wins (a local community pack is on disk when this is
-        called with a ``model_path``); a registry entry whose ``files`` list
-        names the v3 decoder follows; the shared repo's canonical
-        ``s3gen.pt`` is the default, so the missing-file message keeps
-        naming it.
+        called with a ``model_path``), safetensors before any legacy ``.pt``
+        twin; a registry entry whose ``files`` list names a decoder follows;
+        the Single Language Packs' ``s3gen_v3.safetensors`` is the default,
+        so the missing-file message keeps naming it.
         """
         if os.path.isdir(pack_dir):
             for name in MTL_S3GEN_CHECKPOINTS:
@@ -881,7 +988,7 @@ class ChatterboxLoader:
         _refuse_wrong_variant_pack(pack_dir, model_name, entry_point="multilingual")
         t3_model = ChatterboxLoader._resolve_mtl_t3_file(pack_dir, model_name, t3_model)
         s3gen_file = ChatterboxLoader._resolve_mtl_s3gen_file(pack_dir, model_name)
-        required = (*MTL_CHECKPOINT_FILES, s3gen_file, t3_model)
+        required = (*MTL_CHECKPOINT_FILES, "ve.safetensors", s3gen_file, t3_model)
 
         from .constants import CHATTERBOX_REPO_ID
 
@@ -892,7 +999,6 @@ class ChatterboxLoader:
             required,
             model_name,
             client_id,
-            companion_files=entry.get("companion_files"),
         )
 
         missing = ChatterboxLoader._missing_checkpoint_files(pack_dir, required)
diff --git a/modules/model_discovery.py b/modules/model_discovery.py
index 1d71b62..a91541f 100644
--- a/modules/model_discovery.py
+++ b/modules/model_discovery.py
@@ -87,13 +87,18 @@ def _scan(root: str) -> List[Tuple[str, str]]:
     Uses ``os.scandir`` rather than ``os.listdir`` so the directory is read
     once and each entry's type comes from the readdir data already in hand.
     Every subdirectory counts as a pack: a partially downloaded one must stay
-    selectable so the download can finish it.
+    selectable so the download can finish it. The reserved shared-weight
+    store (``SHARED_ASSET_DIR_NAME``) is not a pack and never appears.
     """
+    from .model_info import SHARED_ASSET_DIR_NAME
+
     packs: List[Tuple[str, str]] = []
     try:
         with os.scandir(root) as entries:
             for entry in entries:
                 try:
+                    if entry.name == SHARED_ASSET_DIR_NAME:
+                        continue
                     if entry.is_dir():
                         packs.append((entry.name, entry.path))
                 except OSError as exc:
diff --git a/modules/model_info.py b/modules/model_info.py
index a30c57e..afe8182 100644
--- a/modules/model_info.py
+++ b/modules/model_info.py
@@ -68,6 +68,21 @@ __all__ = [
 # grapheme map the vendored ``MTLTokenizer`` loads instead of a fast tokenizer.
 MTL_TOKENIZER_FILE = "grapheme_mtl_merged_expanded_v1.json"
 
+# ── Shared assets ─────────────────────────────────────────────────────
+# Byte-identical across every repo that ships them (verified 2026-10-07 by
+# sha256 and HF LFS OIDs), so they are fetched at most once into the
+# reserved `_shared` store and hardlinked into each pack that needs them.
+# Downloads never fetch them into a pack directly.
+SHARED_ASSET_DIR_NAME = "_shared"
+SHARED_ASSET_FILES = frozenset(
+    {
+        "ve.safetensors",
+        "s3gen.safetensors",
+        "s3gen_v3.safetensors",
+        MTL_TOKENIZER_FILE,
+    }
+)
+
 
 MODEL_CONFIGS: Dict[str, Dict[str, Any]] = {
     # The pack a saved workflow names by default. Monolingual English, voice
@@ -87,7 +102,7 @@ MODEL_CONFIGS: Dict[str, Dict[str, Any]] = {
         "architecture": "chatterbox_multilingual",
         "sample_rate": 24000,
         "size_gb": 2.7,
-        "files": ["t3_cfg.safetensors", "ve.safetensors", "s3gen.safetensors", "tokenizer.json", "conds.pt"],
+        "files": ["t3_cfg.safetensors", "ve.safetensors", "s3gen.safetensors", MTL_TOKENIZER_FILE, "conds.pt"],
         "description": "Original single-language T3 weights, used by the multilingual loader as its v1.",
     },
     "T3_v2": {
@@ -95,7 +110,7 @@ MODEL_CONFIGS: Dict[str, Dict[str, Any]] = {
         "architecture": "chatterbox_multilingual",
         "sample_rate": 24000,
         "size_gb": 2.7,
-        "files": ["t3_mtl23ls_v2.safetensors", "ve.safetensors", "s3gen.safetensors", "tokenizer.json", "conds.pt"],
+        "files": ["t3_mtl23ls_v2.safetensors", "ve.safetensors", "s3gen.safetensors", MTL_TOKENIZER_FILE, "conds.pt"],
         "description": "23-language multilingual T3 (upstream default).",
     },
     "T3_v3": {
@@ -103,21 +118,22 @@ MODEL_CONFIGS: Dict[str, Dict[str, Any]] = {
         "architecture": "chatterbox_multilingual",
         "sample_rate": 24000,
         "size_gb": 2.7,
-        "files": ["t3_mtl23ls_v3.safetensors", "ve.safetensors", "s3gen.safetensors", "tokenizer.json", "conds.pt"],
+        "files": ["t3_mtl23ls_v3.safetensors", "ve.safetensors", "s3gen.safetensors", MTL_TOKENIZER_FILE, "conds.pt"],
         "description": "23-language multilingual T3, newer checkpoint: better similarity, fewer hallucinations.",
     },
     # The Single Language Pack: six dedicated finetunes of the multilingual
     # V3 family, one per priority language (2026-06 release). Each ships its
-    # own per-language t3 checkpoint ("t3_checkpoint") and s3gen_v3.pt; only
-    # zh-cmn bundles ve.pt and conds.pt -- the rest take ve.pt from the shared
-    # repo at load time ("companion_files") and have NO built-in voice, so a
-    # reference clip is required.
+    # own per-language t3 checkpoint ("t3_checkpoint"); the s3gen_v3 decoder,
+    # grapheme tokenizer and voice encoder are byte-identical across all six
+    # and come from the shared store (SHARED_ASSET_FILES). Only zh-cmn
+    # bundles a conds.pt (built-in voice); the rest have none, so a reference
+    # clip is required.
     "chatterbox-multilingual-zh-cmn": {
         "repo_id": "ResembleAI/Chatterbox-Multilingual-zh-cmn",
         "architecture": "chatterbox_multilingual",
         "sample_rate": 24000,
         "size_gb": 2.8,
-        "files": ["t3_zh_cmn.safetensors", "s3gen_v3.pt", MTL_TOKENIZER_FILE, "ve.pt", "conds.pt"],
+        "files": ["t3_zh_cmn.safetensors", "s3gen_v3.safetensors", MTL_TOKENIZER_FILE, "conds.pt"],
         "t3_checkpoint": "t3_zh_cmn.safetensors",
         "language": "zh",
         "description": "Single Language Pack: Chinese (zh). Ships a built-in voice.",
@@ -127,10 +143,9 @@ MODEL_CONFIGS: Dict[str, Dict[str, Any]] = {
         "architecture": "chatterbox_multilingual",
         "sample_rate": 24000,
         "size_gb": 2.6,
-        "files": ["t3_es_mx_latam.safetensors", "s3gen_v3.pt", MTL_TOKENIZER_FILE],
+        "files": ["t3_es_mx_latam.safetensors", "s3gen_v3.safetensors", MTL_TOKENIZER_FILE],
         "t3_checkpoint": "t3_es_mx_latam.safetensors",
         "language": "es",
-        "companion_files": {"ve.pt": CHATTERBOX_REPO_ID},
         "description": "Single Language Pack: Latin-American Spanish (es). Needs a reference clip.",
     },
     "chatterbox-multilingual-es-es": {
@@ -138,10 +153,9 @@ MODEL_CONFIGS: Dict[str, Dict[str, Any]] = {
         "architecture": "chatterbox_multilingual",
         "sample_rate": 24000,
         "size_gb": 2.6,
-        "files": ["t3_es_es.safetensors", "s3gen_v3.pt", MTL_TOKENIZER_FILE],
+        "files": ["t3_es_es.safetensors", "s3gen_v3.safetensors", MTL_TOKENIZER_FILE],
         "t3_checkpoint": "t3_es_es.safetensors",
         "language": "es",
-        "companion_files": {"ve.pt": CHATTERBOX_REPO_ID},
         "description": "Single Language Pack: Spain Spanish (es). Needs a reference clip.",
     },
     "chatterbox-multilingual-pt-br": {
@@ -149,10 +163,9 @@ MODEL_CONFIGS: Dict[str, Dict[str, Any]] = {
         "architecture": "chatterbox_multilingual",
         "sample_rate": 24000,
         "size_gb": 2.6,
-        "files": ["t3_pt_br.safetensors", "s3gen_v3.pt", MTL_TOKENIZER_FILE],
+        "files": ["t3_pt_br.safetensors", "s3gen_v3.safetensors", MTL_TOKENIZER_FILE],
         "t3_checkpoint": "t3_pt_br.safetensors",
         "language": "pt",
-        "companion_files": {"ve.pt": CHATTERBOX_REPO_ID},
         "description": "Single Language Pack: Brazilian Portuguese (pt). Needs a reference clip.",
     },
     "chatterbox-multilingual-pt-pt": {
@@ -160,10 +173,9 @@ MODEL_CONFIGS: Dict[str, Dict[str, Any]] = {
         "architecture": "chatterbox_multilingual",
         "sample_rate": 24000,
         "size_gb": 2.6,
-        "files": ["t3_pt_pt.safetensors", "s3gen_v3.pt", MTL_TOKENIZER_FILE],
+        "files": ["t3_pt_pt.safetensors", "s3gen_v3.safetensors", MTL_TOKENIZER_FILE],
         "t3_checkpoint": "t3_pt_pt.safetensors",
         "language": "pt",
-        "companion_files": {"ve.pt": CHATTERBOX_REPO_ID},
         "description": "Single Language Pack: Portugal Portuguese (pt). Needs a reference clip.",
     },
     "chatterbox-multilingual-hi": {
@@ -171,10 +183,9 @@ MODEL_CONFIGS: Dict[str, Dict[str, Any]] = {
         "architecture": "chatterbox_multilingual",
         "sample_rate": 24000,
         "size_gb": 2.6,
-        "files": ["t3_hi.safetensors", "s3gen_v3.pt", MTL_TOKENIZER_FILE],
+        "files": ["t3_hi.safetensors", "s3gen_v3.safetensors", MTL_TOKENIZER_FILE],
         "t3_checkpoint": "t3_hi.safetensors",
         "language": "hi",
-        "companion_files": {"ve.pt": CHATTERBOX_REPO_ID},
         "description": "Single Language Pack: Hindi (hi). Needs a reference clip.",
     },
     # The Turbo family, in ONE folder. Turbo is the family's name upstream
@@ -190,7 +201,7 @@ MODEL_CONFIGS: Dict[str, Dict[str, Any]] = {
         "architecture": "chatterbox_turbo",
         "sample_rate": 24000,
         "size_gb": 1.4,
-        "files": ["t3_turbo_v1.safetensors", "ve.safetensors", "s3gen.safetensors", "s3gen_meanflow.safetensors", "tokenizer.json", "conds.pt"],
+        "files": ["t3_turbo_v1.safetensors", "t3_turbo_v1.yaml", "ve.safetensors", "s3gen.safetensors", "s3gen_meanflow.safetensors", "tokenizer.json", "conds.pt", "vocab.json", "merges.txt", "tokenizer_config.json", "added_tokens.json", "special_tokens_map.json"],
         "description": "350M English model with paralinguistic tags; lower VRAM.",
     },
     # A quarter of Turbo again; runs on CPU at realtime. Shares the Turbo
@@ -203,12 +214,15 @@ MODEL_CONFIGS: Dict[str, Dict[str, Any]] = {
         "size_gb": 2.9,
         "files": [
             "t3_nano_v1.safetensors",
+            "t3_nano_v1.yaml",
             "ve.safetensors",
             "s3gen.safetensors",
             "s3gen_meanflow.safetensors",
             "vocab.json",
             "merges.txt",
             "tokenizer_config.json",
+            "added_tokens.json",
+            "special_tokens_map.json",
             "conds.pt",
         ],
         "description": "Turbo-family 110M model for CPU and tight latency budgets. "
@@ -227,6 +241,10 @@ MODEL_CONFIGS: Dict[str, Dict[str, Any]] = {
         "sample_rate": 24000,
         "size_gb": 3.1,
         "files": ["t3_flash.safetensors", "s3gen.safetensors", "ve.safetensors", "tokenizer.json"],
+        # Flash's s3gen.safetensors is a DIFFERENT decoder than the one the
+        # other families share despite the same filename -- it must never be
+        # resolved from, or linked into, the shared store.
+        "unique_files": ["s3gen.safetensors"],
         "description": "Block-diffusion Chatterbox: fast parallel decoding. Needs a "
         "reference audio clip.",
     },
@@ -260,7 +278,8 @@ CHATTERBOX_WEIGHT_FILES = (
     "t3_flash.safetensors",
     "ve.safetensors",
     "s3gen.safetensors",
-    "s3gen_v3.pt",  # Single Language Pack decoder (P-036)
+    "s3gen_v3.safetensors",  # Single Language Pack decoder (P-036)
+    "s3gen_v3.pt",  # legacy serialization, still loaded when present
     "s3gen.pt",
 )
 
diff --git a/src/PATCHES.md b/src/PATCHES.md
index 7952d0a..92ecc9f 100644
--- a/src/PATCHES.md
+++ b/src/PATCHES.md
@@ -58,7 +58,7 @@ ascending order.
 | P-034 | `chatterbox/models/s3gen/s3gen.py` | `S3Token2Mel.forward` | compat patch | The ref-dict casting loop no longer dtype-casts integer tensors: `prompt_token` (token ids) and `prompt_token_len` (lengths) are integers that must move between devices but never between dtypes. Under a bf16 flow the old blanket cast rounded the combined token length 635 down to 632 (bf16's 7-bit mantissa), truncating the padding mask and crashing `flow.inference` with a shape mismatch — and quietly corrupted token ids above 256 that bf16 cannot represent exactly. In fp32 the cast was an exact no-op, so upstream never noticed; device movement is preserved for both branches. |
 | P-019 | `chatterbox/models/t3/t3.py` | `T3.inference` | ComfyUI-API patch | Accepts `pbar` and advances it once per sampled token. `max_new_tokens` keeps upstream's default of `None` but now falls back to `self.hp.max_speech_tokens` instead of raising, so the node may omit it. |
 | P-025 | `chatterbox/mtl_tts.py` | `_apply_watermark` | feature addition | Same optional-`perth` patch as P-023 for the multilingual entry point. Also applies the `str(device)` comparison of P-003 and P-007 in `ChatterboxMultilingualTTS.from_local`, which upstream still compares raw. |
-| P-036 | `chatterbox/mtl_tts.py` | `_resolve_s3gen_checkpoint` | compat patch | The Single Language Pack finetunes (`ResembleAI/Chatterbox-Multilingual-zh-cmn` and its five siblings) ship their S3Gen decoder as `s3gen_v3.pt`, while the shared multilingual repo ships `s3gen.pt` — upstream's hard-coded `s3gen.pt` load made every SLP pack fail at the file check. `_resolve_s3gen_checkpoint` picks whichever the pack holds (preferring `s3gen.pt`), the completeness check tests that name, and `from_local` loads it. `REQUIRED_CHECKPOINT_FILES` drops `s3gen.pt` (now pack-dependent, resolved by the caller alongside the T3 filename), and `modules/loader.py`'s `MTL_CHECKPOINT_FILES` follows. The s3gen state-dict load is non-strict for the same reason: the SLP checkpoints predate the persistent `tokenizer._mel_filters`/`tokenizer.window` buffers (see `S3Token2Wav.ignore_state_dict_missing`), which are recomputed in `__init__` and never learned — a strict load refuses every SLP pack. The classic entry point already loads s3gen non-strict. |
+| P-036 | `chatterbox/mtl_tts.py` | `_resolve_s3gen_checkpoint` | compat patch | The Single Language Pack finetunes (`ResembleAI/Chatterbox-Multilingual-zh-cmn` and its five siblings) ship their S3Gen decoder as `s3gen_v3.safetensors` (plus a legacy `.pt` twin), while the shared multilingual repo ships `s3gen.safetensors` — upstream's hard-coded `s3gen.pt` load made every SLP pack fail at the file check. `_resolve_s3gen_checkpoint` picks whichever serialization the pack holds (safetensors first), `_resolve_ve_checkpoint` does the same for the voice encoder, and `_load_checkpoint` dispatches `load_file`/`torch.load` by extension, so a pack may carry either form. `REQUIRED_CHECKPOINT_FILES` shrinks to the grapheme tokenizer; the resolved ve/s3gen/T3 names join the required set at call time. The s3gen state-dict load is non-strict for a related reason: the SLP checkpoints predate the persistent `tokenizer._mel_filters`/`tokenizer.window` buffers (see `S3Token2Wav.ignore_state_dict_missing`), which are recomputed in `__init__` and never learned — a strict load refuses every SLP pack. The classic entry point already loads s3gen non-strict. `from_pretrained`'s `allow_patterns` fetch the safetensors serializations only — the repo's `.pt` twins are the same weights and are never loaded. |
 | P-029 | `chatterbox/mtl_tts.py` | `_require_checkpoint_files` | compat patch | Same patch as P-027 for `ChatterboxMultilingualTTS.from_local`. Its set differs: `ve.pt`, `s3gen.pt` and `grapheme_mtl_merged_expanded_v1.json`, plus the T3 checkpoint for the selected version. That last name is not fixed, so `from_local` appends the already-resolved `t3_model` to the tuple rather than the helper hard-coding it. |
 | P-026 | `chatterbox/tts_turbo.py` | `_apply_watermark` | feature addition | Same optional-`perth` patch as P-023 for the turbo entry point. Also applies the `str(device)` comparison of P-003 and P-007 in `ChatterboxTurboTTS.from_local`, which upstream still compares raw, and makes `pyloudnorm` an optional import — it is used only by `norm_loudness`, which already degrades gracefully, so the module-level hard import was making the whole entry point unimportable without it. |
 | P-030 | `chatterbox/tts_turbo.py` | `_require_checkpoint_files` | compat patch | Same patch as P-027 for `ChatterboxTurboTTS.from_local`, covering Turbo and Nano together — there is no separate Nano module, so there is no separate `from_local`. The variant's T3 checkpoint (`t3_turbo_v1.safetensors` or `t3_nano_v1.safetensors`) is appended by the caller for the same reason as P-029. |
diff --git a/src/chatterbox/mtl_tts.py b/src/chatterbox/mtl_tts.py
index e0b8ade..aba143b 100644
--- a/src/chatterbox/mtl_tts.py
+++ b/src/chatterbox/mtl_tts.py
@@ -37,26 +37,48 @@ MULTILINGUAL_T3_MODELS = {
 }
 
 # PATCHED (src/PATCHES.md P-027): the file set a multilingual pack has to hold
-# *besides* the version-selected T3 checkpoint, and the up-front check for it.
-# The T3 filename is version-dependent and the s3gen filename is
-# pack-dependent (P-036); both are resolved by the caller, so neither is in
-# this tuple.
+# *besides* the resolved T3, voice-encoder and s3gen checkpoints, and the
+# up-front check for it. The other three filenames are pack-dependent (P-036)
+# and resolved by the caller, so none of them is in this tuple.
 REQUIRED_CHECKPOINT_FILES = (
-    "ve.pt",
     "grapheme_mtl_merged_expanded_v1.json",
 )
 
 
 # PATCHED (src/PATCHES.md P-036): the Single Language Pack finetunes ship
-# their S3Gen decoder as ``s3gen_v3.pt``; the shared multilingual repo ships
-# ``s3gen.pt``. Resolve whichever the pack actually holds -- ``s3gen.pt``
-# stays the fallback so the missing-file message names the canonical file
-# when neither exists.
+# their S3Gen decoder as ``s3gen_v3.safetensors`` (plus a legacy ``.pt``
+# twin), while the shared multilingual repo ships ``s3gen.safetensors``.
+# Resolve whichever serialization the pack actually holds, preferring
+# safetensors (no pickle, what every other entry point loads); the canonical
+# ``s3gen.safetensors`` stays the fallback so the missing-file message names
+# it when nothing exists.
 def _resolve_s3gen_checkpoint(ckpt_dir):
-    for name in ("s3gen.pt", "s3gen_v3.pt"):
+    for name in (
+        "s3gen_v3.safetensors",
+        "s3gen_v3.pt",
+        "s3gen.safetensors",
+        "s3gen.pt",
+    ):
         if (Path(ckpt_dir) / name).is_file():
             return name
-    return "s3gen.pt"
+    return "s3gen.safetensors"
+
+
+def _resolve_ve_checkpoint(ckpt_dir):
+    """The voice-encoder file the pack holds, safetensors preferred (P-036)."""
+    for name in ("ve.safetensors", "ve.pt"):
+        if (Path(ckpt_dir) / name).is_file():
+            return name
+    return "ve.safetensors"
+
+
+def _load_checkpoint(path, map_location=None):
+    """Read a state dict from either serialization, by extension (P-036)."""
+    if str(path).endswith(".safetensors"):
+        from safetensors.torch import load_file
+
+        return load_file(str(path))
+    return torch.load(path, map_location=map_location, weights_only=True)
 
 
 def _require_checkpoint_files(ckpt_dir, required):
@@ -272,10 +294,15 @@ class ChatterboxMultilingualTTS:
 
         # PATCHED (src/PATCHES.md P-027): an incomplete directory is refused
         # here, by name, instead of at the first `torch.load`.
-        # PATCHED (src/PATCHES.md P-036): the s3gen filename follows the pack.
+        # PATCHED (src/PATCHES.md P-036): the s3gen and ve filenames follow
+        # the pack (safetensors preferred); the resolved names join the
+        # required set so the missing-file message names what is actually
+        # expected here.
+        ve_checkpoint = _resolve_ve_checkpoint(ckpt_dir)
         s3gen_checkpoint = _resolve_s3gen_checkpoint(ckpt_dir)
         _require_checkpoint_files(
-            ckpt_dir, (*REQUIRED_CHECKPOINT_FILES, s3gen_checkpoint, t3_model)
+            ckpt_dir,
+            (*REQUIRED_CHECKPOINT_FILES, ve_checkpoint, s3gen_checkpoint, t3_model),
         )
 
         # Always load to CPU first for non-CUDA devices to handle CUDA-saved models
@@ -289,8 +316,11 @@ class ChatterboxMultilingualTTS:
             map_location = None
 
         ve = VoiceEncoder()
+        # PATCHED (src/PATCHES.md P-036): resolve the voice-encoder file the
+        # pack actually holds (safetensors preferred) instead of hard-coding
+        # the legacy ``ve.pt`` name.
         ve.load_state_dict(
-            torch.load(ckpt_dir / "ve.pt", map_location=map_location, weights_only=True)
+            _load_checkpoint(ckpt_dir / _resolve_ve_checkpoint(ckpt_dir), map_location)
         )
         ve.to(device).eval()
 
@@ -308,7 +338,7 @@ class ChatterboxMultilingualTTS:
         # recomputed in __init__, never learned. Load non-strict like the
         # classic path in tts.py does; a strict load refuses every SLP pack.
         s3gen.load_state_dict(
-            torch.load(ckpt_dir / s3gen_checkpoint, map_location=map_location, weights_only=True),
+            _load_checkpoint(ckpt_dir / s3gen_checkpoint, map_location),
             strict=False,
         )
         s3gen.to(device).eval()
@@ -343,7 +373,10 @@ class ChatterboxMultilingualTTS:
                 repo_id=REPO_ID,
                 repo_type="model",
                 revision="main",
-                allow_patterns=["ve.pt", t3_model, "s3gen.pt", "grapheme_mtl_merged_expanded_v1.json", "conds.pt", "Cangjie5_TC.json"],
+                # PATCHED (src/PATCHES.md P-036): fetch the safetensors
+                # serializations only -- the repo's ``.pt`` twins are the
+                # same weights and never loaded.
+                allow_patterns=["ve.safetensors", t3_model, "s3gen.safetensors", "grapheme_mtl_merged_expanded_v1.json", "conds.pt", "Cangjie5_TC.json"],
                 token=os.getenv("HF_TOKEN"),
             )
         )
diff --git a/tests/test_local_checkpoint.py b/tests/test_local_checkpoint.py
index 513abb1..24d492f 100644
--- a/tests/test_local_checkpoint.py
+++ b/tests/test_local_checkpoint.py
@@ -366,12 +366,18 @@ class TestIncompleteDirectoryIsRefused:
             assert "_require_checkpoint_files(" in source, key
 
     def test_the_multilingual_set_is_the_pt_layout(self, real_vendor) -> None:
-        """The two fixed files; the s3gen + t3 names are resolved per pack (P-036)."""
-        assert MTL_CHECKPOINT_FILES == (
-            "ve.pt",
-            "grapheme_mtl_merged_expanded_v1.json",
+        """The grapheme tokenizer is fixed; ve + s3gen + t3 resolve per pack (P-036).
+
+        The resolution order prefers the safetensors serializations -- the
+        ``.pt`` twins hold the same weights and are never fetched.
+        """
+        assert MTL_CHECKPOINT_FILES == ("grapheme_mtl_merged_expanded_v1.json",)
+        assert MTL_S3GEN_CHECKPOINTS == (
+            "s3gen_v3.safetensors",
+            "s3gen_v3.pt",
+            "s3gen.safetensors",
+            "s3gen.pt",
         )
-        assert MTL_S3GEN_CHECKPOINTS == ("s3gen.pt", "s3gen_v3.pt")
         assert real_vendor["mtl_tts"].REQUIRED_CHECKPOINT_FILES == MTL_CHECKPOINT_FILES
 
     def test_the_turbo_set_is_shared_by_turbo_and_nano(self, real_vendor) -> None:
@@ -410,7 +416,7 @@ class TestIncompleteDirectoryIsRefused:
             )
         message = str(caught.value)
         assert "t3_mtl23ls_v3.safetensors" in message
-        assert "ve.pt" in message and "s3gen.pt" in message
+        assert "ve.safetensors" in message and "s3gen_v3.safetensors" in message
         assert str(empty) in message
 
     def test_the_turbo_loader_refusal_names_the_missing_files(self, tmp_path, monkeypatch) -> None:
diff --git a/tests/test_patcher.py b/tests/test_patcher.py
index a6b93ad..d378a99 100644
--- a/tests/test_patcher.py
+++ b/tests/test_patcher.py
@@ -733,8 +733,13 @@ class TestLoaderSurface:
         empty.mkdir()
         attempts: list[tuple] = []
 
-        def record_download_pack(model_name, repo_id, local_dir, client_id=None):
+        patterns_seen: list = []
+
+        def record_download_pack(
+            model_name, repo_id, local_dir, client_id=None, allow_patterns=None
+        ):
             attempts.append((model_name, repo_id, local_dir, client_id))
+            patterns_seen.append(allow_patterns)
 
         monkeypatch.setattr(
             ChatterboxLoader, "download_pack", staticmethod(record_download_pack)
@@ -752,6 +757,10 @@ class TestLoaderSurface:
             "load_model must attempt a download before giving up; the failure "
             "message is only truthful if it did"
         )
+        # The classic fetch is filtered: shared weights come from the store.
+        assert patterns_seen == [
+            ["t3_cfg.safetensors", "tokenizer.json", "conds.pt"]
+        ]
 
     def test_download_pack_is_skipped_for_a_complete_pack(self, pack_dir) -> None:
         called: list[tuple] = []
diff --git a/tests/test_shared_assets.py b/tests/test_shared_assets.py
new file mode 100644
index 0000000..6f37c8a
--- /dev/null
+++ b/tests/test_shared_assets.py
@@ -0,0 +1,200 @@
+"""The shared-weight store (2026-10-07 dedupe).
+
+``ve.safetensors``, ``s3gen.safetensors``, ``s3gen_v3.safetensors`` and the
+grapheme tokenizer are byte-identical across every repo that ships them, so
+they are fetched at most once into the reserved ``_shared`` directory and
+hardlinked into each pack. Downloads carry only the pack-unique files.
+"""
+
+from __future__ import annotations
+
+import os
+
+import pytest
+
+from ComfyUI_Chatterbox.modules import model_discovery
+from ComfyUI_Chatterbox.modules.loader import ChatterboxLoader
+from ComfyUI_Chatterbox.modules.model_info import (
+    CHATTERBOX_WEIGHT_FILES,
+    MTL_TOKENIZER_FILE,
+    SHARED_ASSET_DIR_NAME,
+    SHARED_ASSET_FILES,
+)
+
+SHARED_STORE = ("ve.safetensors", "s3gen.safetensors", "s3gen_v3.safetensors", MTL_TOKENIZER_FILE)
+
+
+@pytest.fixture()
+def models_root(tmp_path, monkeypatch):
+    """A private Chatterbox models root per test."""
+    root = tmp_path / "models" / "tts" / "chatterbox"
+    monkeypatch.setattr(model_discovery, "get_models_root", lambda: str(root))
+    return root
+
+
+class TestTheScanSkipsTheSharedStore:
+    def test_the_reserved_store_is_never_a_pack(self, models_root) -> None:
+        store = models_root / SHARED_ASSET_DIR_NAME
+        pack = models_root / "some-pack"
+        store.mkdir(parents=True)
+        pack.mkdir(parents=True)
+        assert model_discovery._scan(str(models_root)) == [("some-pack", str(pack))]
+
+
+class TestSharedAssetMaterialization:
+    def test_a_shared_file_is_linked_from_the_store(self, models_root) -> None:
+        store = models_root / SHARED_ASSET_DIR_NAME
+        store.mkdir(parents=True)
+        (store / "ve.safetensors").write_bytes(b"ve-weights")
+        pack = models_root / "fresh-pack"
+        pack.mkdir(parents=True)
+
+        ChatterboxLoader._ensure_shared_assets(pack, ["ve.safetensors"])
+
+        linked = pack / "ve.safetensors"
+        assert linked.read_bytes() == b"ve-weights"
+        assert os.stat(store / "ve.safetensors").st_nlink == 2
+
+    def test_a_legacy_full_repo_folder_is_used_before_any_fetch(
+        self, models_root, monkeypatch
+    ) -> None:
+        legacy = models_root / "chatterbox"
+        legacy.mkdir(parents=True)
+        (legacy / "s3gen_v3.safetensors").write_bytes(b"v3-decoder")
+        pack = models_root / "slp"
+        pack.mkdir(parents=True)
+
+        fetched: list = []
+
+        def refuse_fetch(**kwargs):
+            fetched.append(kwargs)
+
+        monkeypatch.setattr("huggingface_hub.hf_hub_download", refuse_fetch)
+
+        ChatterboxLoader._ensure_shared_assets(pack, ["s3gen_v3.safetensors"])
+
+        assert (pack / "s3gen_v3.safetensors").read_bytes() == b"v3-decoder"
+        assert not fetched, "a byte-identical legacy copy must not be re-fetched"
+
+    def test_a_missing_shared_file_is_fetched_into_the_store(
+        self, models_root, monkeypatch
+    ) -> None:
+        pack = models_root / "slp"
+        pack.mkdir(parents=True)
+
+        def fake_fetch(*, repo_id, filename, local_dir):
+            path = os.path.join(local_dir, filename)
+            with open(path, "wb") as handle:
+                handle.write(b"fresh")
+            return path
+
+        monkeypatch.setattr("huggingface_hub.hf_hub_download", fake_fetch)
+
+        ChatterboxLoader._ensure_shared_assets(pack, ["ve.safetensors"])
+
+        assert (pack / "ve.safetensors").read_bytes() == b"fresh"
+        assert (
+            models_root / SHARED_ASSET_DIR_NAME / "ve.safetensors"
+        ).read_bytes() == b"fresh"
+
+    def test_a_pack_that_already_holds_the_file_is_left_alone(self, models_root) -> None:
+        pack = models_root / "slp"
+        pack.mkdir(parents=True)
+        (pack / "ve.safetensors").write_bytes(b"pack-own")
+
+        ChatterboxLoader._ensure_shared_assets(pack, ["ve.safetensors"])
+
+        assert (pack / "ve.safetensors").read_bytes() == b"pack-own"
+
+
+class TestFilteredDownloads:
+    """The fetch carries pack-unique files only; shared ones never download."""
+
+    def _run(self, monkeypatch, models_root, model_name, required, entry):
+        from ComfyUI_Chatterbox.modules import model_info
+
+        monkeypatch.setitem(model_info.MODEL_CONFIGS, model_name, entry)
+        seen: dict = {}
+
+        def fake_download(model_name, repo_id, local_dir, client_id=None, allow_patterns=None):
+            seen["patterns"] = allow_patterns
+            seen["repo_id"] = repo_id
+
+        monkeypatch.setattr(ChatterboxLoader, "download_pack", fake_download)
+
+        def fake_fetch(*, repo_id, filename, local_dir):
+            path = os.path.join(local_dir, filename)
+            with open(path, "wb") as handle:
+                handle.write(b"shared")
+            return path
+
+        monkeypatch.setattr("huggingface_hub.hf_hub_download", fake_fetch)
+
+        ChatterboxLoader._ensure_entry_point_dir(
+            str(models_root / "pack-dir"),
+            entry["repo_id"],
+            required,
+            model_name,
+        )
+        return seen
+
+    def test_an_slp_download_carries_only_its_unique_files(
+        self, models_root, monkeypatch
+    ) -> None:
+        entry = {
+            "repo_id": "ResembleAI/Chatterbox-Multilingual-zh-cmn",
+            "files": [
+                "t3_zh_cmn.safetensors",
+                "s3gen_v3.safetensors",
+                MTL_TOKENIZER_FILE,
+                "conds.pt",
+            ],
+        }
+        seen = self._run(
+            monkeypatch,
+            models_root,
+            "chatterbox-multilingual-zh-cmn",
+            ("grapheme_mtl_merged_expanded_v1.json", "ve.safetensors",
+             "s3gen_v3.safetensors", "t3_zh_cmn.safetensors"),
+            entry,
+        )
+        assert seen["patterns"] == ["t3_zh_cmn.safetensors", "conds.pt"]
+
+    def test_flash_keeps_its_own_s3gen_decoder(self, models_root, monkeypatch) -> None:
+        from ComfyUI_Chatterbox.modules import model_info
+
+        entry = dict(model_info.MODEL_CONFIGS["chatterbox-flash"])
+        seen = self._run(
+            monkeypatch,
+            models_root,
+            "chatterbox-flash",
+            ("ve.safetensors", "s3gen.safetensors", "t3_flash.safetensors",
+             "tokenizer.json"),
+            entry,
+        )
+        assert "s3gen.safetensors" in seen["patterns"]
+        assert "ve.safetensors" not in seen["patterns"]
+
+    def test_the_turbo_fetch_keeps_the_meanflow_decoder(
+        self, models_root, monkeypatch
+    ) -> None:
+        from ComfyUI_Chatterbox.modules import model_info
+
+        entry = dict(model_info.MODEL_CONFIGS["chatterbox-turbo"])
+        seen = self._run(
+            monkeypatch,
+            models_root,
+            "chatterbox-turbo",
+            ("ve.safetensors", "s3gen.safetensors", "s3gen_meanflow.safetensors",
+             "t3_turbo_v1.safetensors"),
+            entry,
+        )
+        assert "s3gen_meanflow.safetensors" in seen["patterns"]
+        assert "ve.safetensors" not in seen["patterns"]
+        assert "s3gen.safetensors" not in seen["patterns"]
+
+
+class TestTheSharedSetIsRealWeights:
+    def test_every_shared_asset_is_a_recognised_weight(self) -> None:
+        for name in SHARED_ASSET_FILES:
+            assert name in CHATTERBOX_WEIGHT_FILES or name == MTL_TOKENIZER_FILE
diff --git a/tests/test_tts_routing.py b/tests/test_tts_routing.py
index 1c1e878..21907e7 100644
--- a/tests/test_tts_routing.py
+++ b/tests/test_tts_routing.py
@@ -601,13 +601,13 @@ class TestSingleLanguagePackRouting:
             ChatterboxLoader._resolve_mtl_s3gen_file(
                 str(tmp_path / "missing"), "chatterbox-multilingual-zh-cmn"
             )
-            == "s3gen_v3.pt"
+            == "s3gen_v3.safetensors"
         )
         assert (
             ChatterboxLoader._resolve_mtl_s3gen_file(
                 str(tmp_path / "missing"), "unknown-local-pack"
             )
-            == "s3gen.pt"
+            == "s3gen_v3.safetensors"
         )
 
     def test_a_slp_dir_sniffs_as_multilingual(self, tmp_path) -> None: