update create_optimizer for updated api

* upgrade transformers to 5.1.0 and torchao to 0.16.0

* upgrade trl for parity

* handle trl api changes

* orpo doesn't have max_prompt_len to check anymore

* cpoconfig doesn't take max_prompt_length and fix cpu offload

* slow fsdp1 test

* triton min 3.4.0 and liger to 0.7.0

* use transformers main for now for zero3 fix

* handle group_by_length change

* fix changes upstream

* mark skip flaky test

* use transformers latest release 5.2.0

docs/cli.qmd

@@ -210,6 +210,8 @@ axolotl lm-eval config.yml
 Configuration options:
 
 ```yaml
+lm_eval_model: # model to evaluate (local or hf path)
+
 # List of tasks to evaluate
 lm_eval_tasks:
   - arc_challenge
@@ -218,7 +220,7 @@ lm_eval_batch_size: # Batch size for evaluation
 output_dir: # Directory to save evaluation results
 ```
 
-See [LM Eval Harness](https://github.com/EleutherAI/lm-evaluation-harness) for more details.
+See [LM Eval Harness integration docs](https://docs.axolotl.ai/docs/custom_integrations.html#language-model-evaluation-harness-lm-eval) for full configuration details.
 
 ### delinearize-llama4
 

requirements.txt

@@ -2,21 +2,21 @@
 
 # START section of dependencies that don't install on Darwin/MacOS
 bitsandbytes==0.49.1
-triton>=3.0.0
+triton>=3.4.0
 mamba-ssm==1.2.0.post1
 xformers>=0.0.23.post1
-liger-kernel==0.6.4
+liger-kernel==0.7.0
 # END section
 
 packaging==26.0
 huggingface_hub>=1.1.7
 peft>=0.18.1
 tokenizers>=0.22.1
-transformers==5.0.0
+transformers @ git+https://github.com/winglian/transformers.git@refactor-inner-training-loop-reorder-only
 accelerate==1.12.0
 datasets==4.5.0
 deepspeed>=0.18.3
-trl==0.27.1
+trl==0.28.0
 hf_xet==1.2.0
 kernels==0.11.5
 
@@ -63,7 +63,7 @@ langdetect==1.0.9
 immutabledict==4.2.0
 antlr4-python3-runtime==4.13.2
 
-torchao==0.13.0
+torchao==0.16.0
 openenv-core==0.1.0
 schedulefree==1.4.1
 

src/axolotl/core/builders/causal.py

@@ -246,7 +246,8 @@ class HFCausalTrainerBuilder(TrainerBuilderBase):
             ddp_find_unused_parameters
         )
 
-        training_arguments_kwargs["group_by_length"] = self.cfg.group_by_length
+        if self.cfg.group_by_length:
+            training_arguments_kwargs["train_sampling_strategy"] = "group_by_length"
         training_arguments_kwargs["curriculum_sampling"] = self.cfg.curriculum_sampling
 
         training_arguments_kwargs["sample_packing"] = bool(self.cfg.sample_packing)

src/axolotl/core/builders/rl.py

@@ -11,7 +11,6 @@ from axolotl.core.trainers import (
 )
 from axolotl.core.trainers.dpo import DPOStrategy
 from axolotl.core.trainers.dpo.args import AxolotlDPOConfig
-from axolotl.core.trainers.grpo import GRPOStrategy
 from axolotl.integrations.base import PluginManager
 from axolotl.loaders.utils import ensure_dtype
 from axolotl.utils.callbacks.qat import QATCallback
@@ -53,6 +52,8 @@ class HFRLTrainerBuilder(TrainerBuilderBase):
         trainer_cls_args = [self.model]
 
         if self.cfg.rl in {RLType.GRPO, RLType.GDPO}:
+            from axolotl.core.trainers.grpo import GRPOStrategy
+
             trainer_cls = GRPOStrategy.get_trainer_class(
                 sequence_parallel=self.cfg.context_parallel_size > 1
             )
@@ -133,21 +134,17 @@ class HFRLTrainerBuilder(TrainerBuilderBase):
             if self.cfg.cpo_alpha is not None:
                 training_args_kwargs["cpo_alpha"] = self.cfg.cpo_alpha
 
-            # Handle when max_prompt_length == max_length from defaults
+            blocklist_args_kwargs.append("max_prompt_length")
-            # CPOTrainer requires strictly less than
-            if (
-                training_args_kwargs["max_prompt_length"]
-                == training_args_kwargs["max_length"]
-            ):
-                training_args_kwargs["max_prompt_length"] -= 1
 
         elif self.cfg.rl is RLType.ORPO:
             training_args_cls = AxolotlORPOConfig
 
+            blocklist_args_kwargs.append("max_prompt_length")
+
         elif self.cfg.rl is RLType.KTO:
             training_args_cls = AxolotlKTOConfig
             # KTOConfig in TRL >= 0.27.0 no longer accepts max_prompt_length
-            blocklist_args_kwargs = ["max_prompt_length"]
+            blocklist_args_kwargs.append("max_prompt_length")
 
             training_args_kwargs["desirable_weight"] = (
                 self.cfg.kto_desirable_weight or 1.0
@@ -157,6 +154,8 @@ class HFRLTrainerBuilder(TrainerBuilderBase):
             )
 
         elif self.cfg.rl in {RLType.GRPO, RLType.GDPO}:
+            from axolotl.core.trainers.grpo import GRPOStrategy
+
             training_args_cls = GRPOStrategy.get_training_args_class()
             training_args_kwargs.update(GRPOStrategy.set_training_args_kwargs(self.cfg))
             blocklist_args_kwargs = GRPOStrategy.get_blocklist_args_kwargs()

src/axolotl/core/trainers/dpo/trainer.py

@@ -57,16 +57,18 @@ class AxolotlDPOTrainer(
     def tokenize_row(
         features,
         processing_class,
-        max_prompt_length,
+        max_prompt_length: int | None = None,
-        max_completion_length,
+        max_completion_length: int | None = None,
-        add_special_tokens,
+        add_special_tokens: bool = True,
+        is_chat: bool = False,
     ) -> Dict:
         res = DPOTrainer.tokenize_row(
             features,
             processing_class,
-            max_prompt_length,
+            max_prompt_length=max_prompt_length,
-            max_completion_length,
+            max_completion_length=max_completion_length,
-            add_special_tokens,
+            add_special_tokens=add_special_tokens,
+            is_chat=is_chat,
         )
         # fix when the tokenizer doesn't have a bos_token_id, e.g. Qwen
         if processing_class.bos_token is None and res["prompt_input_ids"][0] is None:

src/axolotl/core/trainers/mixins/optimizer.py

@@ -104,7 +104,7 @@ class OptimizerMixin(Trainer):
 
         return optimizer_grouped_parameters
 
-    def create_optimizer(self):
+    def create_optimizer(self, model=None):
         if (
             self.args.loraplus_lr_ratio is None
             and self.args.embedding_lr_scale is None
@@ -112,9 +112,9 @@ class OptimizerMixin(Trainer):
             and self.args.lr_groups is None
             and self.optimizer_cls_and_kwargs is None
         ):
-            return super().create_optimizer()
+            return super().create_optimizer(model=model)
 
-        opt_model = self.model_wrapped if is_sagemaker_mp_enabled() else self.model
+        opt_model = self.model if model is None else model
 
         if (
             not self.optimizer

src/axolotl/integrations/kernels/README.md

@@ -0,0 +1,44 @@
+# Kernels Integration
+
+MoE (Mixture of Experts) kernels speed up training for MoE layers and reduce VRAM costs. In transformers v5, `batched_mm` and `grouped_mm` were integrated as built-in options via the `experts_implementation` config kwarg:
+
+```python
+class ExpertsInterface(GeneralInterface):
+    _global_mapping = {
+        "batched_mm": batched_mm_experts_forward,
+        "grouped_mm": grouped_mm_experts_forward,
+    }
+```
+
+In our custom integration, we add support for **ScatterMoE**, which is even more efficient and faster than `grouped_mm`.
+
+## Usage
+
+Add the following to your axolotl YAML config:
+
+```yaml
+plugins:
+  - axolotl.integrations.kernels.KernelsPlugin
+
+use_kernels: true
+use_scattermoe: true
+```
+
+**Important:** Setting `experts_implementation` is incompatible with `use_scattermoe`.
+
+## How It Works
+
+The `KernelsPlugin` runs before model loading and:
+
+1. Registers the ScatterMoE kernel from the [`axolotl-ai-co/scattermoe`](https://huggingface.co/axolotl-ai-co/scattermoe) Hub repo.
+2. Patches the model's `SparseMoeBlock` forward method with the optimized ScatterMoE implementation.
+
+This works for any MoE model in transformers that uses a `SparseMoeBlock` class (Mixtral, Qwen2-MoE, OLMoE, etc.).
+
+## Limitations
+
+ScatterMoE uses a softmax -> topk routing, so results may be different for some model arch as baseline (GPT-OSS, GLM_MOE_DSA).
+
+## Note on MegaBlocks
+
+We tested [MegaBlocks](https://huggingface.co/kernels-community/megablocks) but were unable to ensure numerical accuracy, so we did not integrate it. It was also incompatible with many newer model architectures in transformers.

src/axolotl/integrations/lm_eval/README.md

@@ -6,6 +6,12 @@ See https://github.com/EleutherAI/lm-evaluation-harness
 
 ## Usage
 
+There are two ways to use the LM Eval integration:
+
+### 1. Post-Training Evaluation
+
+When training with the plugin enabled, evaluation runs automatically after training completes:
+
 ```yaml
 plugins:
   - axolotl.integrations.lm_eval.LMEvalPlugin
@@ -16,9 +22,50 @@ lm_eval_tasks:
   - arc_easy
 
 lm_eval_batch_size: # Batch size for evaluation
-output_dir: # Directory to save evaluation results
+
+# Directory to save evaluation results.
+# The final model is loaded from this directory
+# unless specified otherwise (see below)
+output_dir:
 ```
 
+Run training as usual:
+```bash
+axolotl train config.yml
+```
+
+### 2. Standalone CLI Evaluation
+
+Evaluate any model directly without training:
+
+```yaml
+lm_eval_model: meta-llama/Llama-2-7b-hf
+
+plugins:
+  - axolotl.integrations.lm_eval.LMEvalPlugin
+
+lm_eval_tasks:
+  - gsm8k
+  - hellaswag
+  - arc_easy
+
+lm_eval_batch_size: 8
+output_dir: ./outputs
+```
+
+Run evaluation:
+```bash
+axolotl lm-eval config.yml
+```
+
+## Model Selection Priority
+
+The model to evaluate is selected in the following priority order:
+
+1. **`lm_eval_model`** - Explicit model path or HuggingFace repo (highest priority)
+2. **`hub_model_id`** - Trained model pushed to HuggingFace Hub
+3. **`output_dir`** - Local checkpoint directory containing trained model weights
+
 ## Citation
 
 ```bib

src/axolotl/integrations/lm_eval/__init__.py

@@ -5,7 +5,7 @@ Module for the Plugin for LM Eval Harness
 import subprocess  # nosec
 
 from axolotl.integrations.base import BasePlugin
-from axolotl.integrations.lm_eval.cli import build_lm_eval_command
+from axolotl.integrations.lm_eval.cli import build_lm_eval_command, get_model_path
 
 from .args import LMEvalArgs as LMEvalArgs
 
@@ -29,7 +29,7 @@ class LMEvalPlugin(BasePlugin):
                 wandb_project=cfg.wandb_project,
                 wandb_entity=cfg.wandb_entity,
                 wandb_name=cfg.wandb_name,
-                model=cfg.lm_eval_model or cfg.hub_model_id,
+                model=get_model_path(cfg),
             ):
                 subprocess.run(  # nosec
                     lm_eval_args,

src/axolotl/integrations/lm_eval/cli.py

@@ -13,6 +13,21 @@ import yaml
 from axolotl.utils.dict import DictDefault
 
 
+def get_model_path(cfg: DictDefault) -> str | None:
+    """
+    Determine which model path to use for evaluation.
+
+    Priority order (highest to lowest):
+    1. lm_eval_model - Explicit model path override
+    2. hub_model_id - Model pushed to HuggingFace Hub
+    3. None - Falls back to output_dir in build_lm_eval_command
+
+    Returns:
+        Model path string or None to use output_dir fallback
+    """
+    return cfg.lm_eval_model or cfg.hub_model_id or None
+
+
 def build_lm_eval_command(
     tasks: list[str],
     bfloat16=True,
@@ -108,7 +123,7 @@ def lm_eval(config: str, cloud: Optional[str] = None):
             wandb_project=cfg.wandb_project,
             wandb_entity=cfg.wandb_entity,
             wandb_name=cfg.wandb_name,
-            model=cfg.lm_eval_model or cfg.hub_model_id,
+            model=get_model_path(cfg),
             revision=cfg.revision,
             apply_chat_template=cfg.apply_chat_template,
             fewshot_as_multiturn=cfg.fewshot_as_multiturn,

src/axolotl/loaders/patch_manager.py

@@ -10,6 +10,7 @@ from functools import cached_property
 import addict
 import transformers
 from transformers import PretrainedConfig, PreTrainedModel
+from transformers.modeling_flash_attention_utils import is_flash_attn_available
 
 from axolotl.integrations.base import PluginManager
 from axolotl.monkeypatch.multipack import (
@@ -500,6 +501,7 @@ class PatchManager:
             and not self.cfg.trust_remote_code
             and not self.cfg.gptq
             and self.cfg.flash_attention
+            and is_flash_attn_available()
             and not self.inference
         ):
             # TODO(MengqingCao): split these patches separately

src/axolotl/monkeypatch/gradient_checkpointing/offload_cpu.py

@@ -59,7 +59,12 @@ class CPU_Offloaded_Gradient_Checkpointer(torch.autograd.Function):
         hidden_states = hidden_states.to("cuda", non_blocking=True).detach()
         hidden_states.requires_grad = True
         with torch.enable_grad():
-            (output,) = ctx.forward_function(hidden_states, *ctx.args)
+            output = ctx.forward_function(hidden_states, *ctx.args)
+            # Newer HF models (e.g. Qwen3MoE) using GradientCheckpointingLayer
+            # return a plain tensor, not a tuple.  Older models return tuples
+            # like (hidden_states, present_kv, ...).  Unwrap if needed.
+            if isinstance(output, (tuple, list)):
+                (output,) = output
         torch.autograd.backward(output, dY)
         return (
             None,

src/axolotl/monkeypatch/transformers/trainer_loss_calc.py

@@ -28,8 +28,12 @@ PATCHED_EVAL_CODE = {
     "array": 'metrics[f"{metric_key_prefix}_loss"] = np.nanmean(all_losses).item()',
 }
 
-ORIGINAL_MAYBE_CODE = "tr_loss_scalar = self._nested_gather(tr_loss).mean().item()"
+ORIGINAL_MAYBE_CODE = (
-PATCHED_MAYBE_CODE = "tr_loss_scalar = self._nested_gather(tr_loss).nanmean().item()"
+    "tr_loss_scalar = nested_gather(tr_loss, self.args.parallel_mode).mean().item()"
+)
+PATCHED_MAYBE_CODE = (
+    "tr_loss_scalar = nested_gather(tr_loss, self.args.parallel_mode).nanmean().item()"
+)
 
 
 def check_evaluation_loop_is_patchable() -> bool:

src/axolotl/utils/schemas/config.py

@@ -446,7 +446,16 @@ class AxolotlInputConfig(
         },
     )
 
-    unfrozen_parameters: list[str] | None = None
+    unfrozen_parameters: list[str] | None = Field(
+        default=None,
+        json_schema_extra={
+            "description": "List of regex patterns for parameter names to keep unfrozen. "
+            "All other parameters will be frozen via requires_grad=False. "
+            "Note: range-based patterns (e.g. embed_tokens.weight$[:32000]) use gradient "
+            "zeroing rather than a true freeze, so weight decay will still apply to the "
+            "frozen portion and optimizer states are allocated for the full parameter."
+        },
+    )
 
     sequence_len: int = Field(
         default=512,

tests/core/test_builders.py

@@ -300,7 +300,6 @@ class TestHFRLTrainerBuilder:
         self._test_common_training_arguments(training_arguments, rl=orpo_cfg.rl)
         # ORPO specific
         assert training_arguments.beta == 0.1  # maps from orpo_alpha
-        assert training_arguments.max_prompt_length == 512
 
     def test_kto_training_arguments(self, kto_cfg, model, tokenizer):
         builder = HFRLTrainerBuilder(kto_cfg, model, tokenizer)

tests/e2e/multigpu/test_fsdp1.py

@@ -186,6 +186,7 @@ class TestFSDP1:
 
         verify_training_success(temp_dir)
 
+    @pytest.mark.skip(reason="slow test, deprecate fsdp1 asap")
     def test_dpo_fft(self, temp_dir):
         cfg = DictDefault(
             {

tests/e2e/multigpu/test_fsdp2.py

@@ -365,6 +365,7 @@ class TestFSDP2:
 
         verify_training_success(temp_dir)
 
+    @pytest.mark.skip(reason="slow test w cu129 + torch 2.9.1 + py3.12")
     @require_torch_2_7_0
     def test_dpo_fft(self, temp_dir):
         cfg = DictDefault(

tests/prompt_strategies/test_chat_templates.py

@@ -115,6 +115,9 @@ class TestAssistantChatTemplateLlama3:
 
     def test_phi35(self, phi35_tokenizer, assistant_dataset):
         LOG.info("Testing phi-3.5 with assistant dataset")
+        assert "LlamaTokenizer" in phi35_tokenizer.__class__.__name__, (
+            "phi35 tokenizer should be a LlamaTokenizer"
+        )
         strategy = ChatTemplateStrategy(
             ChatTemplatePrompter(
                 phi35_tokenizer,
@@ -140,13 +143,13 @@ class TestAssistantChatTemplateLlama3:
         # fmt: off
         expected_input_ids = [
             32010,  # user
-            22172, 32007,  # user eot
+            12199, 32007,  # user eot
             32001,  # assistant
-            22172, 32007,  # assistant eot
+            12199, 32007,  # assistant eot
             32010,  # user
-            1781, 26966, 32007,  # user eot
+            16773, 26966, 32007,  # user eot
             32001,  # assistant
-            1781, 26966, 32007,  # assistant eot
+            16773, 26966, 32007,  # assistant eot
         ]
         expected_labels = [
             -100,  # user
@@ -156,7 +159,7 @@ class TestAssistantChatTemplateLlama3:
             -100,  # user
             -100, -100, -100,  # user eot
             -100,  # assistant
-            1781, 26966, 32007,  # assistant eot
+            16773, 26966, 32007,  # assistant eot
         ]
         # fmt: on
         LOG.debug(f"Expected input_ids: {expected_input_ids}")

tests/test_tokenizers.py

@@ -84,7 +84,8 @@ class TestTokenizers:
             }
         )
         tokenizer = load_tokenizer(cfg)
-        assert tokenizer("<|im_start|>user")["input_ids"] == [1, 32000, 1404]
+        assert "LlamaTokenizer" in tokenizer.__class__.__name__
+        assert tokenizer("<|im_start|>user")["input_ids"] == [1, 32000, 1792]
         assert len(tokenizer) == 32001
 
         # ensure reloading the tokenizer again from cfg results in same vocab length