slicktune.merge

PEFT multi-adapter loading and TIES / DARE-style merges.

Attributes

MERGE_METHODS
MergeMethod

Classes

AdapterRef	Reference to a PEFT adapter directory used in a multi-adapter load or merge.
MergeResult	Artifacts written by merge_adapters() or bake_adapter().

Functions

bake_adapter(→ MergeResult)	Merge a single PEFT adapter into base weights for serving.
load_multi_adapters(→ tuple[Any, ...)	Load a base model with one or more PEFT adapters attached.
merge_adapters(→ MergeResult)	Combine PEFT adapters with a PEFT weighted-merge method and save the result.
parse_adapter_ref(→ AdapterRef)	Parse a CLI-style adapter spec path or path:weight.

Package Contents

class slicktune.merge.AdapterRef

Reference to a PEFT adapter directory used in a multi-adapter load or merge.

Parameters:

• path (str or Path) – Directory containing adapter_config.json and adapter weights.

• name (str) – PEFT adapter name used when loading / combining.

• weight (float, optional) – Merge weight for this adapter, by default 1.0.

name: str

path: str | pathlib.Path

weight: float = 1.0

slicktune.merge.MERGE_METHODS: frozenset[str]

slicktune.merge.MergeMethod

class slicktune.merge.MergeResult

Artifacts written by merge_adapters() or bake_adapter().

Parameters:

• output_dir (Path) – Directory containing the merged adapter or baked full model.

• adapter_name (str or None) – Name of the combined PEFT adapter when baked is False.

• baked (bool) – Whether adapters were merged into base weights via merge_and_unload.

adapter_name: str | None

baked: bool

output_dir: pathlib.Path

slicktune.merge.bake_adapter(*, adapter_dir: str | pathlib.Path, output_dir: str | pathlib.Path, model_id: str | None = None) → MergeResult

Merge a single PEFT adapter into base weights for serving.

Parameters:

• adapter_dir (str or Path) – Directory from Tuner.fit() containing adapter weights.

• output_dir (str or Path) – Destination for the full merged Hugging Face checkpoint.

• model_id (str or None, optional) – Base model id. When omitted, read from adapter_config.json.

Returns:

MergeResult – Baked checkpoint metadata.

Raises:

• ValueError – If the adapter directory is invalid or base_model_name_or_path is missing when model_id is not provided.

• FileNotFoundError – If adapter_config.json is missing.

slicktune.merge.load_multi_adapters(*, model_id: str, adapters: list[AdapterRef], active: str | None = None) → tuple[Any, transformers.PreTrainedTokenizerBase]

Load a base model with one or more PEFT adapters attached.

Parameters:

• model_id (str) – Hugging Face id or local path of the base causal LM.

• adapters (list of AdapterRef) – Adapters to attach (at least one). Names must be unique.

• active (str or None, optional) – Adapter name to activate after load. Defaults to the first adapter.

Returns:

tuple[Any, PreTrainedTokenizerBase] – (peft_model, tokenizer).

Raises:

ValueError – If adapters is empty, names collide, or an adapter dir is invalid.

slicktune.merge.merge_adapters(*, model_id: str, adapters: list[AdapterRef], output_dir: str | pathlib.Path, method: MergeMethod | str = 'ties', density: float | None = 0.5, bake: bool = False, combined_name: str = 'merged') → MergeResult

Combine PEFT adapters with a PEFT weighted-merge method and save the result.

Parameters:

• model_id (str) – Base model id used when the adapters were trained.

• adapters (list of AdapterRef) – Adapters to combine (at least two for a true merge; one is allowed and simply selects / optionally bakes that adapter).

• output_dir (str or Path) – Destination directory for the combined adapter or baked model.

• method (str, optional) – PEFT combination_type (e.g. ties, dare_ties, linear), by default ties.

• density (float or None, optional) – Prune density in [0, 1] for TIES / DARE / magnitude methods. Ignored for methods that do not use density. Default 0.5.

• bake (bool, optional) – If True, call merge_and_unload and save a full HF checkpoint.

• combined_name (str, optional) – Name of the new weighted adapter, by default merged.

Returns:

MergeResult – Paths and bake flag for the written artifacts.

Raises:

ValueError – If inputs are invalid, method is unknown, or adapters have incompatible LoRA ranks for method.

slicktune.merge.parse_adapter_ref(spec: str) → AdapterRef

Parse a CLI-style adapter spec path or path:weight.

Parameters:

spec (str) – Adapter directory path, optionally followed by :weight.

Returns:

AdapterRef – Parsed reference with a name derived from the path stem.

Raises:

ValueError – If spec is empty.