fix: use ungated llama tokenizer mirrors

renderers/base.py

@@ -1152,6 +1152,17 @@ def _model_has_vision_config(model_name: str) -> bool:
 }
 
 
+# Tokenizer repos to use when a canonical model repo is gated but an
+# audited unrestricted mirror ships byte-identical tokenizer files and
+# chat_template. The returned tokenizer keeps the caller's original
+# ``name_or_path`` so exact-match renderer resolution still uses
+# ``MODEL_RENDERER_MAP``.
+TOKENIZER_SOURCE_OVERRIDES: dict[str, str] = {
+    "meta-llama/Llama-3.2-1B-Instruct": "unsloth/Llama-3.2-1B-Instruct",
+    "meta-llama/Llama-3.2-3B-Instruct": "unsloth/Llama-3.2-3B-Instruct",
+}
+
+
 # Models for which ``fastokens`` is known to diverge from vanilla
 # ``transformers.AutoTokenizer`` and therefore must NOT be patched.
 # Empirical audit ran each entry of ``MODEL_RENDERER_MAP`` through both
@@ -1175,6 +1186,42 @@ def _model_has_vision_config(model_name: str) -> bool:
 _FASTOKENS_ANNOUNCED = False
 
 
+def _tokenizer_source_for(model_name_or_path: str) -> str:
+    return TOKENIZER_SOURCE_OVERRIDES.get(model_name_or_path, model_name_or_path)
+
+
+def _tokenizer_load_kwargs(model_name_or_path: str) -> dict[str, Any]:
+    revision = TRUSTED_REVISIONS.get(model_name_or_path)
+    if revision is not None:
+        return {"trust_remote_code": True, "revision": revision}
+    return {"trust_remote_code": False}
+
+
+def _preserve_requested_tokenizer_name(
+    tokenizer,
+    *,
+    requested_name_or_path: str,
+    loaded_name_or_path: str,
+):
+    if requested_name_or_path == loaded_name_or_path:
+        return tokenizer
+
+    try:
+        tokenizer.name_or_path = requested_name_or_path
+    except Exception:
+        init_kwargs = getattr(tokenizer, "init_kwargs", None)
+        if isinstance(init_kwargs, dict):
+            init_kwargs["name_or_path"] = requested_name_or_path
+
+    if getattr(tokenizer, "name_or_path", "") != requested_name_or_path:
+        raise RuntimeError(
+            f"Loaded tokenizer for {requested_name_or_path!r} from "
+            f"{loaded_name_or_path!r}, but could not preserve the requested "
+            "name_or_path for renderer auto-resolution."
+        )
+    return tokenizer
+
+
 def _patched_load(model_name_or_path: str, **kwargs):
     """Run ``AutoTokenizer.from_pretrained`` with fastokens patched in
     process-locally — patch around the load, unpatch right after.
@@ -1312,29 +1359,41 @@ def load_tokenizer(
     validation for configs with nested ``rope_parameters``), we fall
     back to loading the repo's self-contained ``tokenizer.json``
     directly — see ``_load_tokenizer_via_auto``.
-    """
-    kwargs: dict[str, Any] = {}
-    revision = TRUSTED_REVISIONS.get(model_name_or_path)
-    if revision is not None:
-        kwargs = {"trust_remote_code": True, "revision": revision}
-    else:
-        kwargs = {"trust_remote_code": False}
 
-    if not use_fastokens or model_name_or_path in FASTOKENS_INCOMPATIBLE:
-        return _load_tokenizer_via_auto(model_name_or_path, **kwargs)
+    Canonical Meta Llama-3.2 Instruct repos are gated on HuggingFace. For
+    those exact IDs we load tokenizer files from the audited unrestricted
+    ``unsloth`` mirrors instead, then restore ``tokenizer.name_or_path`` to
+    the requested Meta ID so auto-resolution still selects ``Llama3Renderer``.
+    """
+    load_name_or_path = _tokenizer_source_for(model_name_or_path)
+    kwargs = _tokenizer_load_kwargs(load_name_or_path)
+
+    if not use_fastokens or load_name_or_path in FASTOKENS_INCOMPATIBLE:
+        tok = _load_tokenizer_via_auto(load_name_or_path, **kwargs)
+        return _preserve_requested_tokenizer_name(
+            tok,
+            requested_name_or_path=model_name_or_path,
+            loaded_name_or_path=load_name_or_path,
+        )
 
     try:
-        return _patched_load(model_name_or_path, **kwargs)
+        tok = _patched_load(load_name_or_path, **kwargs)
     except Exception as exc:
         logger.info(
             "fastokens could not load %r (%s: %s); falling back to vanilla "
             "AutoTokenizer. Add this model to FASTOKENS_INCOMPATIBLE in "
             "renderers.base to suppress the retry.",
-            model_name_or_path,
+            load_name_or_path,
             type(exc).__name__,
             str(exc)[:160],
         )
-        return _load_tokenizer_via_auto(model_name_or_path, **kwargs)
+        tok = _load_tokenizer_via_auto(load_name_or_path, **kwargs)
+
+    return _preserve_requested_tokenizer_name(
+        tok,
+        requested_name_or_path=model_name_or_path,
+        loaded_name_or_path=load_name_or_path,
+    )
 
 
 def _populate_registry():
@@ -1702,12 +1761,8 @@ def _get_offset_tokenizer(tokenizer):
         if cached is not None:
             return cached
 
-        kwargs: dict[str, Any] = {}
-        revision = TRUSTED_REVISIONS.get(name_or_path)
-        if revision is not None:
-            kwargs = {"trust_remote_code": True, "revision": revision}
-        else:
-            kwargs = {"trust_remote_code": False}
+        load_name_or_path = _tokenizer_source_for(name_or_path)
+        kwargs = _tokenizer_load_kwargs(load_name_or_path)
 
         def _has_offsets(tok) -> bool:
             if not getattr(tok, "is_fast", False):
@@ -1727,7 +1782,12 @@ def _has_offsets(tok) -> bool:
         # off — serialized against pool patch/unpatch via ``_FASTOKENS_PATCH_LOCK``
         # so no concurrent window can swap the shim back in mid-load — then
         # restore the prior patch state. Never cache a non-offset tokenizer.
-        offset_tok = _load_tokenizer_via_auto(name_or_path, **kwargs)
+        offset_tok = _load_tokenizer_via_auto(load_name_or_path, **kwargs)
+        offset_tok = _preserve_requested_tokenizer_name(
+            offset_tok,
+            requested_name_or_path=name_or_path,
+            loaded_name_or_path=load_name_or_path,
+        )
         if not _has_offsets(offset_tok):
             import fastokens
 
@@ -1737,7 +1797,12 @@ def _has_offsets(tok) -> bool:
                     with contextlib.redirect_stdout(io.StringIO()):
                         fastokens.unpatch_transformers()
                 try:
-                    offset_tok = _load_tokenizer_via_auto(name_or_path, **kwargs)
+                    offset_tok = _load_tokenizer_via_auto(load_name_or_path, **kwargs)
+                    offset_tok = _preserve_requested_tokenizer_name(
+                        offset_tok,
+                        requested_name_or_path=name_or_path,
+                        loaded_name_or_path=load_name_or_path,
+                    )
                 finally:
                     if was_patched:
                         with contextlib.redirect_stdout(io.StringIO()):

tests/conftest.py

@@ -47,11 +47,10 @@
     # there's just no byte-output to parity-check against. Split-specific
     # parity (V3 bare prompt vs R1 <think>+history-strip) is covered in
     # tests/test_deepseek_r1.py.
-    # Llama-3 loads via the unrestricted unsloth mirror (byte-identical
-    # chat template) so CI needs no Meta-gated HF token. Pinned to the
-    # explicit "llama-3" config because the mirror name isn't in
-    # MODEL_RENDERER_MAP (so "auto" would fall back to DefaultRenderer).
-    ("unsloth/Llama-3.2-1B-Instruct", "llama-3"),
+    # Llama-3 uses the canonical Meta ID for renderer auto-resolution, while
+    # load_tokenizer fetches the tokenizer/chat_template from the unrestricted
+    # unsloth mirror so CI needs no Meta-gated HF token.
+    ("meta-llama/Llama-3.2-1B-Instruct", "auto"),
     ("openai/gpt-oss-20b", "gpt-oss"),
     ("Qwen/Qwen2.5-0.5B-Instruct", "default"),
 ]
@@ -139,7 +138,7 @@ def _skip_gpt_oss_for_hf_parity_tests(request):
 def _skip_llama_for_hf_parity_tests(request):
     callspec = getattr(request.node, "callspec", None)
     model_name = callspec.params.get("model_name") if callspec else None
-    if model_name != "unsloth/Llama-3.2-1B-Instruct":
+    if model_name != "meta-llama/Llama-3.2-1B-Instruct":
         return
     test_file = os.path.basename(str(request.node.fspath))
     if test_file in _LLAMA_HF_PARITY_TEST_FILES:

tests/test_llama_3.py

@@ -1,10 +1,10 @@
 """Llama-3 renderer coverage.
 
 Covers ``Llama3Renderer`` and the ``meta-llama/Llama-3.2-{1B,3B}-Instruct``
-entries in ``MODEL_RENDERER_MAP``. Tokenizers are loaded via the
-unrestricted ``unsloth/Llama-3.2-{1B,3B}-Instruct`` mirrors (verified
-byte-identical chat templates) so CI doesn't need an HF token with Meta
-license access.
+entries in ``MODEL_RENDERER_MAP``. ``load_tokenizer`` uses the
+unrestricted ``unsloth/Llama-3.2-{1B,3B}-Instruct`` mirrors underneath
+(verified byte-identical chat templates) so CI doesn't need an HF token
+with Meta license access.
 """
 
 from __future__ import annotations
@@ -34,7 +34,7 @@
 @pytest.fixture(scope="module", params=_MODEL_PAIRS, ids=[m for m, _ in _MODEL_PAIRS])
 def llama_pair(request):
     canonical, mirror = request.param
-    tok = load_tokenizer(mirror)
+    tok = load_tokenizer(canonical)
     renderer = Llama3Renderer(tok, Llama3RendererConfig(date_string=_PINNED_DATE))
     return canonical, mirror, tok, renderer
 
@@ -58,6 +58,14 @@ def test_create_renderer_via_explicit_config(llama_pair):
     assert isinstance(r, Llama3Renderer)
 
 
+def test_create_renderer_auto_resolves_after_mirror_load(llama_pair):
+    """``load_tokenizer(canonical_meta_id)`` loads from the unrestricted
+    mirror but preserves the canonical name needed for auto-resolution."""
+    canonical, _, tok, _ = llama_pair
+    assert tok.name_or_path == canonical
+    assert isinstance(create_renderer(tok), Llama3Renderer)
+
+
 # ---------------------------------------------------------------------------
 # Constructor contract
 # ---------------------------------------------------------------------------

tests/test_load_tokenizer.py

@@ -9,9 +9,11 @@
 from __future__ import annotations
 
 import re
+from types import SimpleNamespace
 from unittest.mock import patch
 
-from renderers.base import TRUSTED_REVISIONS, load_tokenizer
+from renderers import base
+from renderers.base import TOKENIZER_SOURCE_OVERRIDES, TRUSTED_REVISIONS, load_tokenizer
 
 
 # ---------------------------------------------------------------------------
@@ -70,6 +72,23 @@ def test_kimi_loads_with_pinned_revision(mock_from_pretrained):
     }
 
 
+@patch("transformers.AutoTokenizer.from_pretrained")
+def test_meta_llama_loads_tokenizer_from_unsloth_mirror(mock_from_pretrained):
+    """Canonical Meta Llama repos are gated; load their tokenizer/chat
+    template from the audited unrestricted mirror while preserving the
+    canonical name for renderer auto-resolution."""
+    canonical = "meta-llama/Llama-3.2-1B-Instruct"
+    mirror = "unsloth/Llama-3.2-1B-Instruct"
+    mock_from_pretrained.return_value = SimpleNamespace(name_or_path=mirror)
+
+    tok = load_tokenizer(canonical, use_fastokens=False)
+
+    args, kwargs = mock_from_pretrained.call_args
+    assert args == (mirror,)
+    assert kwargs == {"trust_remote_code": False}
+    assert tok.name_or_path == canonical
+
+
 @patch("transformers.AutoTokenizer.from_pretrained")
 def test_unknown_path_falls_through_to_no_remote_code(mock_from_pretrained):
     """Unknown / fine-tuned model paths — including ``moonshotai/Kimi-K2*``
@@ -92,6 +111,53 @@ def test_unknown_path_falls_through_to_no_remote_code(mock_from_pretrained):
         )
 
 
+def test_tokenizer_source_overrides_are_exact_llama_mirrors():
+    """Mirror overrides are intentionally narrow: only verified
+    byte-identical Llama tokenizer/template mirrors should live here."""
+    assert TOKENIZER_SOURCE_OVERRIDES == {
+        "meta-llama/Llama-3.2-1B-Instruct": "unsloth/Llama-3.2-1B-Instruct",
+        "meta-llama/Llama-3.2-3B-Instruct": "unsloth/Llama-3.2-3B-Instruct",
+    }
+
+
+def test_offset_tokenizer_uses_unsloth_mirror_for_meta_llama(monkeypatch):
+    """Offset-tokenizer reloads must use the same unrestricted source
+    override, otherwise Llama rendering can hit the gated Meta repo after
+    the initial tokenizer load succeeds."""
+
+    class _NoOffsets:
+        name_or_path = "meta-llama/Llama-3.2-1B-Instruct"
+
+        def __call__(self, *args, **kwargs):
+            raise NotImplementedError("fastokens shim has no offsets")
+
+    class _OffsetTokenizer:
+        is_fast = True
+
+        def __init__(self, name_or_path: str):
+            self.name_or_path = name_or_path
+
+        def __call__(self, *args, **kwargs):
+            return {"offset_mapping": [(0, 1)]}
+
+    calls = []
+
+    def _fake_load(name_or_path, **kwargs):
+        calls.append((name_or_path, kwargs))
+        return _OffsetTokenizer(name_or_path)
+
+    base._offset_tokenizers.clear()
+    monkeypatch.setattr(base, "_load_tokenizer_via_auto", _fake_load)
+
+    try:
+        tok = base._get_offset_tokenizer(_NoOffsets())
+    finally:
+        base._offset_tokenizers.clear()
+
+    assert calls == [("unsloth/Llama-3.2-1B-Instruct", {"trust_remote_code": False})]
+    assert tok.name_or_path == "meta-llama/Llama-3.2-1B-Instruct"
+
+
 # ---------------------------------------------------------------------------
 # Smoke: real tokenizer loads behave as expected
 # ---------------------------------------------------------------------------

tests/test_preserve_thinking.py

@@ -53,6 +53,8 @@ def _make(tokenizer, renderer_name, **flags):
     "poolside/Laguna-XS.2",
     # Llama-3 has no reasoning channel at all — preserve flags can't add
     # or drop anything, so they're pure no-ops.
+    "meta-llama/Llama-3.2-1B-Instruct",
+    "meta-llama/Llama-3.2-3B-Instruct",
     "unsloth/Llama-3.2-1B-Instruct",
 }
 
@@ -324,6 +326,8 @@ def test_preserve_btc_on_live_cycle_matches_all(
     "Qwen/Qwen3-VL-30B-A3B-Instruct",
     # Llama-3 ships no <think> rendering path, so reasoning_content never
     # surfaces in the output regardless of the preserve flags.
+    "meta-llama/Llama-3.2-1B-Instruct",
+    "meta-llama/Llama-3.2-3B-Instruct",
     "unsloth/Llama-3.2-1B-Instruct",
 }