maxtext-v0.2.3

Changes

• Upgraded JAX to version 0.10.0 for pre-training and 0.10.1 for post-training.
• New vLLM-Powered Evaluation Framework: Introduced an eval framework for running lm-eval, evalchemy, and custom benchmarking against MaxText checkpoints. See the evaluation guide for details.
• Added support for pre-training new models:
  • Qwen3.5: Qwen3.5 35B & 397B is now supported.
  • Qwen3-Omni: Support for multimodal SFT (PR #3863).
• Direct Preference Optimization (DPO/ORPO) Support: Full support for DPO and ORPO alignment pipelines. See the DPO tutorial for details.
• Reinforcement Learning (RL) Recipe: Added a pre-configured RL recipe for Qwen3-30b-a3b.
• Iterative Quality Monitoring (RL): Added intermediate evaluation hooks to automatically run quality benchmarks during RL training (every eval_interval steps), optimized with a new eval_batch_size configuration knob.
• Developer Extensibility: Added dataset_processor_path CLI knob for custom dataset integration, and refactored shared post-training hooks to simplify custom SFT, DPO, and RL workflow development.
• Generalized Learn-to-Init (LTI) for Distillation: Enhanced post-training distillation capabilities with generalized LTI support.
• Added support for recording elastic goodput events during training to track efficiency (PR #3901).
• Installation Updates: Updated the [tpu-post-train] installation command to require UV_TORCH_BACKEND=cpu(see Installation Guide).
• Zero1 AOT Compilation: Added zero1 support to Ahead-Of-Time (AOT) compilation in train compile, improving compilation capabilities for zero1 config.
• MoE Performance Optimization: Integrated ragged gather reduce into Mixture of Experts (MoE) layers to optimize memory and performance by replacing ragged scatter and supporting backward pass.
• Added E2E scripts to run checkpoint conversion, pre-training and post-training (SFT, RL) with Gemma3-4B model.
• Bug Fixes and Usability Enhancements:
  • Attention Masking Fix in RL: Fixed an issue in TunixMaxTextAdapter where queries at non-pad positions could attend to pad-position keys during training, which was corrupting log-probabilities and affecting GRPO training reward trajectories (PR #4016).
  • JAX/NNX Gradient Mutation Fix: Refactored post-training loops (train_distill, train_sft, train_rl) to use jax.value_and_grad with explicit NNX state split/merge instead of nesting nnx.value_and_grad inside nnx.jit (PR #3652).
  • Qwen3-MoE Checkpoint Conversion: Fixed checkpoint conversion issues for Qwen3-MoE models (PR #3868).
  • Duplicate Configuration Failures Fix: Allowed identical config overrides and handled configuration exceptions cleanly (PR #3933).
• Documentation Improvements: Updated Getting started guide, including new guides for the evaluation framework and the DPO tutorial.

Deprecations

• Deleted legacy DPO implementation in favor of the integrated DPO trainer.
• Removed stack trace collection feature.