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Adapters

What is a LoRA Adapter?

A LoRA adapter is a small set of delta weights (typically 10--50 MB) that can be loaded on top of a frozen base model. This makes adapters lightweight, portable, and easy to version.

Saving Adapters

After training, the adapter is automatically saved to {output_dir}/adapter/. You can also save manually:

from easylora import save_adapter

save_adapter(model, "./my_adapter", metadata={"task": "summarisation"})

The adapter directory contains:

  • adapter_model.safetensors -- adapter weights
  • adapter_config.json -- PEFT configuration
  • easylora_metadata.json -- optional metadata you provide

Loading Adapters

from easylora import load_adapter

model = load_adapter(
    base_model_name_or_path="meta-llama/Llama-3.2-1B",
    adapter_dir="./my_adapter",
)

Merging Adapters

Merging bakes the adapter weights into the base model, producing a standalone model that does not require PEFT at inference time:

from easylora import merge_adapter

merge_adapter(
    base_model_name_or_path="meta-llama/Llama-3.2-1B",
    adapter_dir="./output/adapter",
    output_dir="./merged_model",
)
easylora merge \
    --base-model meta-llama/Llama-3.2-1B \
    --adapter-dir ./output/adapter \
    --output-dir ./merged_model

The merged model can be loaded with standard HuggingFace APIs:

from transformers import AutoModelForCausalLM
model = AutoModelForCausalLM.from_pretrained("./merged_model")

Output Artifacts

After a training run, the output directory contains:

output/
  adapter/              # LoRA adapter weights
  train_config.json     # Full config used
  train_log.jsonl       # Step-by-step training metrics
  summary.json          # Final loss, steps, runtime
  metadata.json         # Base model, versions, timestamp
  logs.jsonl            # Application logs

Publishing to HuggingFace Hub

Set push_to_hub: true and hub_repo_id in your config:

output:
  push_to_hub: true
  hub_repo_id: "your-username/my-lora-adapter"
  hub_private: true

Ensure you are logged in via huggingface-cli login before training.