Transfer

A modular PyTorch framework for fine-tuning Hugging Face language models.

Transfer simplifies applying techniques like Supervised Fine-Tuning (SFT) and Direct Preference Optimization (DPO) to any Hugging Face causal language model.

Features

• SFT and DPO — two fine-tuning strategies out of the box
• Multi-turn conversation support — point to a messages_column of chat-style message lists
• Completion-only loss masking — train on assistant tokens only with train_on_completions_only
• LoRA / QLoRA — 4-bit quantization (nf4 / fp4) via bitsandbytes, configurable LoRA rank and target modules
• Training loop controls — gradient accumulation, LR scheduling (cosine, linear, constant, …), gradient clipping
• Checkpointing and logging — intermediate checkpoints every N steps, CSV training logs, optional W&B integration
• Built-in evaluation — perplexity and semantic entropy metrics
• CLI — transfer train and transfer infer commands for training and inference without writing Python

Installation

From PyPI

pip install transfer-llm

From source

git clone https://github.com/deduu/transfer.git
cd transfer
pip install .

Quick Start

Single-turn SFT

from datasets import Dataset
from transfer import Trainer, SFTConfig

# Prepare data
dataset = Dataset.from_dict({
    "prompt": ["What is the capital of France?", "Explain gravity."],
    "response": ["The capital of France is Paris.", "Gravity is ..."],
})

# Configure
config = SFTConfig(
    model_name="google/gemma-2b",
    num_epochs=3,
    batch_size=2,
    learning_rate=5e-5,
    output_dir="./gemma-sft",
)

# Train
trainer = Trainer(task="sft", config=config, train_dataset=dataset)
trainer.train()
trainer.save_model()

Multi-turn SFT with completion masking and LoRA

from datasets import Dataset
from transfer import Trainer, SFTConfig

# Each row contains a list of message dicts
conversations = [
    {"messages": [
        {"role": "system", "content": "You are a helpful assistant."},
        {"role": "user", "content": "What is the weather in SF?"},
        {"role": "assistant", "content": "It is 62 F and foggy."},
    ]},
    # ... more conversations
]
dataset = Dataset.from_list(conversations)

config = SFTConfig(
    model_name="meta-llama/Llama-3.2-3B-Instruct",
    messages_column="messages",           # read from chat-style column
    train_on_completions_only=True,       # loss on assistant tokens only
    num_epochs=3,
    batch_size=1,
    learning_rate=2e-5,
    max_length=1024,
    gradient_accumulation_steps=4,
    warmup_steps=10,
    scheduler_type="cosine",
    save_steps=50,
    logging_steps=5,
    use_lora=True,
    lora_r=16,
    lora_alpha=32,
    lora_dropout=0.05,
    output_dir="./agent-sft-output",
)

trainer = Trainer(task="sft", config=config, train_dataset=dataset)
trainer.train()
trainer.save_model()

DPO

from datasets import load_dataset
from transfer import Trainer, DPOConfig

dataset = load_dataset("Anthropic/hh-rlhf", split="train[:1%]")

config = DPOConfig(
    model_name="google/gemma-2b",
    num_epochs=1,
    batch_size=2,
    beta=0.1,
    output_dir="./gemma-dpo",
)

trainer = Trainer(task="dpo", config=config, train_dataset=dataset)
trainer.train()
trainer.save_model()

CLI Usage

The transfer command is installed automatically with the package.

Training

transfer train \
  --task sft \
  --model_name google/gemma-2b \
  --dataset_path data.jsonl \
  --output_dir ./my-sft-model \
  --num_epochs 3 \
  --batch_size 4 \
  --learning_rate 2e-4 \
  --use_lora \
  --gradient_accumulation_steps 4 \
  --scheduler_type cosine \
  --warmup_steps 50 \
  --save_steps 200 \
  --logging_steps 10

Use --messages_column messages --train_on_completions_only for multi-turn datasets.

Inference

transfer infer \
  --model_name google/gemma-2b \
  --adapter_path ./my-sft-model \
  --prompt "Explain quantum computing" \
  --use_chat_template \
  --max_new_tokens 256 \
  --temperature 0.7 \
  --do_sample

Configuration

SFTConfig

DPOConfig

Inherits all parameters from above, plus:

Development

git clone https://github.com/deduu/transfer.git
cd transfer
pip install -e ".[dev]"
pytest tests/ -v

License

MIT