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tao-finetune-cosmos-reason

Cosmos3-Nano video QA supervised fine-tuning with FSDP parallelism. Use when training or evaluating video question-answering models, fine-tuning Cosmos3-Nano or compatible Cosmos Reason models with SFT/LoRA, or working with Cosmos-RL. Trigger phrases include "fine-tune Cosmos", "Cosmos3 Nano Reasoner", "Cosmos-RL SFT", "video QA fine-tune", "Cosmos3-Nano training".

2,984stars345forksUpdated 8/17/2026

Security Assessment

Safe(92/100)
Security Score92/100

About tao-finetune-cosmos-reason

This NVIDIA skill drives supervised fine-tuning (SFT) and evaluation of Cosmos Reason video question-answering models, with the packaged default base model nvidia/Cosmos3-Nano. It solves the complexity of configuring a multi-GPU video-QA training run: it standardizes how the base model is sourced from HuggingFace, how FSDP parallelism is expressed (dp_shard_size for GPU count and dp_replicate_size for node count instead of the usual num_gpus/num_nodes), and when a checkpoint conversion to a Qwen3-VL HF safetensors directory is needed because some Cosmos-RL images cannot load the native Cosmos3 Omni format directly.

The skill is schema-driven and AutoML-aware. Generated TAO Core dataclass schemas live in schemas/<action>.schema.json with a manifest, and each emits a spec_template_<action>.yaml. Reference guides cover launch intake and preflight, evaluation (task types, LoRA eval, selective download, results), and AutoML/HPO policy including mapping objectives like accuracy targets to evaluation metrics and search spaces over learning rate, batch size, and weight decay. Train requests default to AutoML-on and route through a shared tao-run-automl runner when schemas and templates are packaged, falling back to direct training when AutoML is disabled or schemas are missing. Non-train actions (evaluate, inference, quantize) stay in this skill. It requires Docker with the NVIDIA container toolkit, and credentials are handled through the standard HF_TOKEN environment variable, with the user directed to accept the model license and provide a read token for gated models.

Target users are ML engineers and researchers fine-tuning or evaluating Cosmos Reason / Cosmos3-Nano video-QA models. Use cases include SFT and LoRA fine-tuning, accuracy-driven hyperparameter search, and evaluation of video-QA reasoning models.

FAQ

What does this skill fine-tune?

Cosmos Reason video question-answering models, with the packaged default base model hf_model://nvidia/Cosmos3-Nano, using supervised fine-tuning (SFT) and LoRA with FSDP-based parallelism.

What are the system requirements?

Per its metadata it requires Docker plus the NVIDIA container toolkit. Pretrained weights are pulled from HuggingFace, and gated models require an HF_TOKEN with read access after accepting the model agreement.

How is GPU and node count specified?

It uses FSDP parallelism: dp_shard_size sets the GPU count and dp_replicate_size sets the node count, rather than the standard num_gpus/num_nodes fields.

Do I need to convert the base model?

Only for certain Cosmos-RL images that cannot load the native Cosmos3 Omni checkpoint format. In that case you convert Cosmos3-Nano to a Qwen3-VL HF safetensors directory and use that as the pretrained-model path.

How does AutoML work here?

The model is AutoML-enabled by default; train requests route through the shared tao-run-automl runner when the train schema and template are packaged. You can disable it per run (automl_policy: off) for plain training.

All Files

25 files
references/demo_datasets.yaml0.5 KB
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references/cosmos-reason-automl.md5.1 KB
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BENCHMARK.md4.0 KB
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references/cosmos-data-specs.md15.2 KB
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references/cosmos-reason-parameters.md13.9 KB
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references/spec_template_evaluate.yaml1.1 KB
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evals/evals.json0.8 KB
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references/cosmos-actions-parameters.md17.2 KB
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references/cosmos-automl-deft.md5.4 KB
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references/cosmos-reason-launch.md9.2 KB
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references/skill_info.yaml7.5 KB
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references/spec_template_train.yaml2.2 KB
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schemas/quantize.schema.json2.5 KB
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SKILL.md12.1 KB
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references/cosmos-reason-evaluate.md3.6 KB
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references/detailed-guide.md0.6 KB
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references/spec_template_quantize.yaml0.4 KB
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schemas/manifest.json2.7 KB
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skill-card.md4.1 KB
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references/spec_template_inference.yaml0.3 KB
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schemas/inference.schema.json1.7 KB
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scripts/prepare_cosmos3_vlm_checkpoint.py11.0 KB
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schemas/evaluate.schema.json15.7 KB
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schemas/train.schema.json38.0 KB
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skill.oms.sig9.3 KB
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Install tao-finetune-cosmos-reason

Download and extract the skill files to your .claude/skills/ directory.

Quick Setup:

  1. Copy the skill folder to .claude/skills/
  2. Claude will automatically detect and use the skill

Repository

nvidia/skills