# Loader **`class Loader(config)`** Bases: [`Step`](../technical/libnlp/steps/standard.md#squirro.lib.nlp.steps.base.Step) The [`Loader`](#squirro.lib.nlp.steps.loaders.Loader) step adds [`Document`](../technical/libnlp/base.md#squirro.lib.nlp.document.Document) to the [`Pipeline`](../technical/libnlp/base.md#squirro.lib.nlp.pipeline.Pipeline) stream. Therefore, it is most often the first [`Step`](../technical/libnlp/steps/standard.md#squirro.lib.nlp.steps.base.Step) specified. Parameters - `step` ([`str`](https://docs.python.org/3.11/library/stdtypes.html#str)) – loader - `type` ([`str`](https://docs.python.org/3.11/library/stdtypes.html#str)) – Type of [`Loader`](#squirro.lib.nlp.steps.loaders.Loader) - `fields` ([`list`](https://docs.python.org/3.11/library/stdtypes.html#list)`, ``[``]`) – List of fields to load (defaults to empty list)