feat: Add support for OLMo-3 model (#4678)

* feat: Add support for OLMo-3 model in mapping and tests

* Update unsloth/models/mapper.py

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

* Update tests/test_get_model_name.py

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

* Fix casing, add Think variants, and align version gate for OLMo-3 PR 4678

Mapper: switch slugs from OLMo-3 to canonical Olmo-3 mixed case, drop the
non-existent unsloth/Olmo-3-7B-Instruct-bnb-4bit dead alias, and add the
already-published Olmo-3-7B-Think and Olmo-3-32B-Think Unsloth mirrors.

Loader: change the olmo3 transformers version gate from Version("4.57.0")
to Version("4.57.0.dev0") so nightly/source builds that already contain
olmo3 are not blocked, matching the OLMo-2, Gemma 3 and Cohere patterns.

* Use canonical Olmo-3 casing and cover Think variants in OLMo-3 tests

Mirrors the mapper.py fixes on pr-4678-code: HuggingFace canonical slugs
for the OLMo-3 family use mixed-case Olmo-3 (not OLMo-3 like OLMo-2), and
Unsloth already hosts Olmo-3-7B-Think and Olmo-3-32B-Think mirrors, so
the resolution matrix now covers all three published Olmo-3 families.

---------

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
Co-authored-by: Daniel Han <danielhanchen@gmail.com>

tests/test_get_model_name.py

@@ -64,6 +64,42 @@ class TestGetModelName(unittest.TestCase):
                 "unsloth/Ministral-3-3B-Instruct-2512",
                 True,
             ),
+            (
+                "allenai/Olmo-3-7B-Instruct",
+                True,
+                "unsloth/Olmo-3-7B-Instruct-unsloth-bnb-4bit",
+                True,
+            ),
+            (
+                "allenai/Olmo-3-7B-Instruct",
+                False,
+                "unsloth/Olmo-3-7B-Instruct",
+                True,
+            ),
+            (
+                "allenai/Olmo-3-7B-Think",
+                True,
+                "unsloth/Olmo-3-7B-Think-unsloth-bnb-4bit",
+                True,
+            ),
+            (
+                "allenai/Olmo-3-7B-Think",
+                False,
+                "unsloth/Olmo-3-7B-Think",
+                True,
+            ),
+            (
+                "allenai/Olmo-3-32B-Think",
+                True,
+                "unsloth/Olmo-3-32B-Think-unsloth-bnb-4bit",
+                True,
+            ),
+            (
+                "allenai/Olmo-3-32B-Think",
+                False,
+                "unsloth/Olmo-3-32B-Think",
+                True,
+            ),
             ("unsloth/Kimi-K2-Instruct", True, "unsloth/Kimi-K2-Instruct-BF16", True),
             ("unsloth/Kimi-K2-Instruct", False, "unsloth/Kimi-K2-Instruct", False),
             # Fallback-to-original behavior
@@ -113,6 +149,10 @@ class TestGetModelName(unittest.TestCase):
                 "mistralai/ministral-3-3b-instruct-2512",
                 "unsloth/ministral-3-3b-instruct-2512-unsloth-bnb-4bit",
             ),
+            (
+                "allenai/olmo-3-7b-instruct",
+                "unsloth/olmo-3-7b-instruct-unsloth-bnb-4bit",
+            ),
             ("unsloth/kimi-k2-instruct", "unsloth/kimi-k2-instruct-bf16"),
         ]
         for src, expected in contracts:

unsloth/models/loader.py

@@ -1210,13 +1210,20 @@ class FastModel(FastBaseModel):
             # Granite-4 rms norms are stored as 16 bit, but we upcast
             os.environ["UNSLOTH_HIGH_PRECISION_LAYERNORM"] = "1"
             os.environ["UNSLOTH_DISABLE_STATIC_GENERATION"] = "1"
-        # Olmo 2
+        # OLMo 2
         elif "olmo2" in model_types_all and transformers_version < Version(
             "4.50.0.dev0"
         ):
             raise RuntimeError(
                 "Unsloth: OLMo-2 only works on transformers >= 4.50.0." + NIGHTLY
             )
+        # OLMo 3
+        elif "olmo3" in model_types_all and transformers_version < Version(
+            "4.57.0.dev0"
+        ):
+            raise RuntimeError(
+                "Unsloth: OLMo-3 only works on transformers >= 4.57.0." + LATEST
+            )
         elif "falcon_h1" in model_types_all:
             # Falcon must use float32 Triton ie TRITON_F32_DEFAULT = 'ieee'
             # since Mamba kernels error out on using lower precision

unsloth/models/mapper.py

@@ -762,6 +762,18 @@ __INT_TO_FLOAT_MAPPER = \
         "allenai/OLMo-2-0325-32B-Instruct",
         "unsloth/OLMo-2-0325-32B-Instruct-bnb-4bit",
     ),
+    "unsloth/Olmo-3-7B-Instruct-unsloth-bnb-4bit" : (
+        "unsloth/Olmo-3-7B-Instruct",
+        "allenai/Olmo-3-7B-Instruct",
+    ),
+    "unsloth/Olmo-3-7B-Think-unsloth-bnb-4bit" : (
+        "unsloth/Olmo-3-7B-Think",
+        "allenai/Olmo-3-7B-Think",
+    ),
+    "unsloth/Olmo-3-32B-Think-unsloth-bnb-4bit" : (
+        "unsloth/Olmo-3-32B-Think",
+        "allenai/Olmo-3-32B-Think",
+    ),
     "unsloth/Mistral-Small-3.1-24B-Instruct-2503-unsloth-bnb-4bit" : (
         "unsloth/Mistral-Small-3.1-24B-Instruct-2503",
         "mistralai/Mistral-Small-3.1-24B-Instruct-2503",