NVIDIA/Megatron-LM core_v0.18.0

NVIDIA Megatron Core 0.18.0

Repository: NVIDIA/Megatron-LM

Tag: core_v0.18.0

Published: 2026-06-23T00:16:28Z

Prerelease: no

Release notes: Changelog Details

• fix(ci): replace actions/setup-python with apt-get to avoid 429 rate limits by @ko3n1g :: PR: #4072
• ci: Fix package name for code-freeze workflow by @ko3n1g :: PR: #4077
• chore: bump _code_freeze workflow to v0.86.0 by @ko3n1g :: PR: #4078
• Fix checkpoint inspector by @janEbert :: PR: #4079
• Update docs to conform to NVIDIA style guides by @megnvidia :: PR: #4068
• Miscellaneous inference fixes by @santhnm2 :: PR: #4030
• fix fine_grained_callables with fused rmsnorm residual by @CarlosGomes98 :: PR: #4026
• [Main][feat] Support overlapping A2A Combine backprop with wgrad GEMM by @Wohox :: PR: #3795
• Modify mfsdp default data-parallel-sharding-strategy by @wplf :: PR: #3691
• Fix fsdp_dtensor conversion for pretrained-only checkpoints by @DAISY-gh :: PR: #3912
• Guard NVshmem issues by @wdykas :: PR: #4093
• m-fsdp: wire use_precision_aware_optimizer from ddp_config to ParamAn… by @rapatel :: PR: #4024
• Megatron-FSDP: Add MXFP8 transpose helper buffer for Hybrid FSDP by @shjwudp :: PR: #3918
• feat(fsdp): use TE general_gemm for mixed-precision wgrad in FSDP path by @Victarry :: PR: #3822
• Megatron-FSDP: Fix insufficient double buffers during gradient reduce by @shjwudp :: PR: #4054
• Fix M-FSDP MXFP8 related BUGs by @shjwudp :: PR: #3991
• Megatron-FSDP: Make _pre_forward_param_unshard and _register_post_backward_hook formal by @shjwudp :: PR: #4029
• FIX: Use decoupled gradients for precision-aware M-FSDP grad norm by @XueSongTap :: PR: #3746
• Align chat completions endpoint with vLLM by @santhnm2 :: PR: #4063
• [Megatron-FSDP] Fix compatibility with frozen parameters and add unit tests by @shjwudp :: PR: #3287
• [M-FSDP] Refactor uneven dtensor to full tensor and add UT by @shjwudp :: PR: #3190
• Add agent instruction files by @Phlip79 :: PR: #4102
• Bump eopt version by @skyw :: PR: #4100
• Refactor emerging optimizer integration by @skyw :: PR: #4113
• Fix over provisioning of Mamba state memory when max_requests is set by @santhnm2 :: PR: #4114
• base strategy simplification by @dimapihtar :: PR: #4001
• add support for DCP and FSDP async save by @dimapihtar :: PR: #4027
• Add more emerging optimizers (#3907) by @skyw :: PR: #4119
• Fix FSDP checkpoint conversion and loading for Qwen3.5-VL by @DAISY-gh :: PR: #3936
• docs: update mcore optimizer docstrings to google style by @Akshat8510 :: PR: #2799
• Set tensor-parallel attributes irrespective of perform_initialization by @ilml :: PR: #4084
• docs: add developer-guide skill with CI/CD and failure navigation guidance by @ko3n1g :: PR: #4035
• chore: Move skills by @ko3n1g :: PR: #4136
• ci: Let Claude react to comment by @ko3n1g :: PR: #4135
• Nemotron3 Super GB200 release config by @maanug-nv :: PR: #4118
• Enable CUDA graph for ADAM optimizer by @vasunvidia :: PR: #3429
• Claude review should recommend testing by @Phlip79 :: PR: #4137
• cleanup: remove unused scatter_gather_tensors_in_pipeline argument by @Phlip79 :: PR: #4140
• fix: Remove fail-fast (-x) and guard distributed teardown against deadlock by @ko3n1g :: PR: #4139
• Claude: add respond-to-issue skill by @Phlip79 :: PR: #4141
• Fix muon getter backward compatability by @skyw :: PR: #4157
• Audit of user guide by @megnvidia :: PR: #4098
• Fix RerunStateMachine crash (TypeError: 'NoneType' object is not subscriptable) by not saving a checkpoint after a transient NaN / Inf by @yezhengmao1 :: PR: #3981
• Preserve type of decorated methods/classes by @nschank :: PR: #4062
• update muon test case to use new interface by @skyw :: PR: #4163
• [M-FSDP] Fix Tensor Parallel mode detection by @shjwudp :: PR: #3191
• fix: remove weights_only=False for multimodal example by @faradawn :: PR: #4104
• Cudagraphs: Fix sequence packing segfault more generally by @mathemakitten :: PR: #4162
• Make MTP work with materialize_only_last_token_logits by @santhnm2 :: PR: #4166
• Add unit test for Mamba EP inference (eager fallback with mixed CUDA graphs) by @santhnm2 :: PR: #4085
• update docs in respect to async changes by @dimapihtar :: PR: #4177
• update checkpointing docs in respect to async changes by @dimapihtar :: PR: #4208
• chore: improve build-and-test skill with trigger rules and dependency workflow by @ko3n1g :: PR: #4199
• Fix layerwise optimizer with expt_dp_size=1 and contention with element-wise distributed optimizer by @skyw :: PR: #4138
• ci: add --cluster-a100/h100/gb200 args to trigger_internal_ci.py by @ko3n1g :: PR: #4195
• ci: Update golden values for nightly tests by @chtruong814 :: PR: #4215
• rename async_allgather to overlap_param_gather by @skyw :: PR: #4217
• Fix Slack sync for users with GitHub email privacy enabled by @Phlip79 :: PR: #4220
• Miscellaneous MTP inference fixes by @santhnm2 :: PR: #4191
• Move inference guards out of arguments.py by @mathemakitten :: PR: #4210
• Fix: enable fine-grained activation offloading for Mamba model. by @fanshiqing :: PR: #4173
• bump NVRx by @dimapihtar :: PR: #4178
• Update tokenizer args for Nemotron3 release config by @maanug-nv :: PR: #4239
• build: add dynamic git-versioning and drop rc0 pre-release tag by @ko3n1g :: PR: #4212
• Fix unnecessary permute padding for non-quantized MoE dispatch by @xiaoxi-wangfj :: PR: #4038
• Fix split state dict main by @kunlunl :: PR: #3676
• Add /split-pr Claude Code command for splitting PRs by CODEOWNERS by @Phlip79 :: PR: #4160
• Enable FP8 DPA for MXFP8 recipe by @vasunvidia :: PR: #4066
• Enable AG/RS overlap with explicit process group passing by @jeffnvidia :: PR: #3249
• Enable cpu_offloading with Full iteration CUDA graph by @vasunvidia :: PR: #3969
• Fix TransformerConfig validation for mixed dense/MoE upcycling by @rkteddy :: PR: #3647
• Remove cross-rank synchronization during checkpoint load & deprecate torch.distributed.checkpoint.state_dict_loader.load_state_dict by @asolergi-nv :: PR: #2864
• Fix incorrectly set decoupled_grad and DistOpt mechanics for MFSDP. by @cspades :: PR: #4133
• Refit Miscelaneous by @wdykas :: PR: #3973
• Add conditions_embeddings argument to TransformerBlock, TransformerLayer for DiT (diffusion transformer) by @huvunvidia :: PR: #4134
• Fix build_sequences_per_dataset output path arg usage by @DhineshPonnarasan :: PR: #4144
• ci: Flush pending CUDA work before the barrier in destroy_model_parallel by @chtruong814 :: PR: #4259
• Update oncall schedule...