Changes
-
Flax NNX Migration: Enabled
pure_nnx,enable_nnx, andpure_nnx_decoderconfigurations by default (PR #3526), migrating MaxText primarily on Flax NNX (PR #2885). -
Dependency Upgrades: Upgraded JAX to version 0.10.2 for pre-training and 0.11.0 for post-training.
-
Model Support & Architecture:
- DeepSeek-V4: Full model integration, decoders, and configuration stack (PR #4153), added HyperHead, aligned Sinkhorn implementation (PR #4337), and added checkpoint conversion support (PR #4336). See the user guide for more details.
- Qwen3-VL: Added support for Qwen3-VL models (PR #4293, PR #4517) and Qwen3-VL-4B (PR #4263).
- Apple Envy MoE: Added model configurations and support for Apple Envy Switch architectures.
- Chunked MoE: Added chunked MoE support via
num_moe_token_chunksto reduce memory footprint (PR #4499). - Block Diffusion: Added block-diffusion pre-training support (PR #4776), model-independent block corruption utilities (PR #4737), and causal-block attention across Dense, Splash, and Tokamax kernels (PR #4743).
-
LoRA & QLoRA: Added native LoRA and QLoRA support for Gemma4, Gemma3, Qwen3, and Llama3, along with interactive tutorials (PR #3969, PR #4265, PR #4068, PR #3968, PR #3970, PR #4417).
-
Context Parallelism (CP), Ring Attention:
- Added Ulysses and USP CP strategy and packing (PR #4687, PR #4825, PR #4836), Tokamax load-balanced Ring Attention (PR #4266, PR #4537, PR #4622), and sequence packing for USP and All-Gather CP (PR #4230, PR #4887).
- DeepSeek MoE & MLA: Added Ring Attention with DSA Sparse Indexer PR #4767, auxiliary loss-free and sequence-wise load balancing PR #4753, MLA QK head chunking PR #4564, optimized generate_mask PR #4437, and Approximate Top-K PR #4243.
- Positional Embeddings: Added YaRN RoPE config PR #4238, standardized MRoPE to BS3 convention for multimodal training PR #4709, and fixed Qwen3.5 partial rotary factor handling.
- Kernels & Megacore: Added configurable attention_for_vit kernels PR #4232 and enabled Megacore for Splash Attention dkv backward PR #4755.
-
Quantization & Performance: Added FP4 [E2M1] (PR #4495) and experimental attention quantization (PR #4487); enabled TE Collective GEMMs (PR #4470) and overlap (PR #4307), MoE comms with collective matmul (PR #4295), Tokamax GMM v2 (MoE configuration guide), and double-buffered inner scans during gradient accumulation (PR #4316).
-
Checkpointing: Added support for Multi-tier checkpointing in Pathways.
-
Goodput & Elasticity:
-
Post Training:
- Added
reward_functions_pathandreward_functionsCLI knobs for custom rewards (PR #4149) to RL training. - Updated tutorials with
AgenticGRPOLearnerfor async RL training (PR #4181) and added GRPO Gemma4-e4b tutorial (PR #4427). - Added RL support for Qwen3 30B and GPT-OSS 20B. See the Qwen3 30B RL tutorial and GPT-OSS 20B RL tutorial for recipes.
- Added support for DPO along with tutorials (PR #4362).
- Added
-
Usability & Infrastructure:
- Added wandb logging support (PR #3053).
- Added Hugging Face Grain streaming integration and onboarding guide (PR #4486).
- Added Simple-evals runner support for gpt-oss model family (PR #4644).
- Added scripts to run vanilla DiLoCo on MaxText (PR #4095).
- Added option to enable on-demand profiling server in ML Diagnostics (PR #4131).
Bug Fixes
-
Post-Training:
- Resolved Gemma 3/4 RL rollout gibberish issue by unrolling scanned weights for vLLM adapter (PR #4536, PR #4519, PR #4404).
- Fixed RL LR schedule defaults (PR #4225), added
drop_remainder=Trueto prevent shape mismatches on tail batches during GRPO training (PR #4252) and resolved Qwen3.5 MRoPE/Kv-cache rollout issues (PR #4177).
-
Compilation:
-
Model-Specific Fixes:
-
NNX, MoE & MTP:
Deprecations
- Tensor Transpose Parallelism Removed: Completely removed the
tensor_transposephysical mesh axis and deletedici_tensor_transpose_parallelismanddcn_tensor_transpose_parallelismconfiguration options. - Flax Linen Deprecation Warning: Flax Linen is now deprecated in favor of Flax NNX; running with
pure_nnx=Falseorenable_nnx=Falsewill issue a deprecation warning.