# API Reference

This section documents the public Python API of BYOST. Pages are generated automatically from function and module docstrings in the source code, following common scientific-Python documentation practice (Sphinx autodoc with NumPy-style docstrings where provided).

## Modules

| Module | Description |
| ------ | ----------- |
| [`BYOST.build`](build.md) | Build PCA/GPR building blocks from input spectra and conditions |
| [`BYOST.template`](template.md) | Retrieve and reconstruct spectral templates |
| [`BYOST.merge_spec`](merge_spec.md) | Merge blue- and red-side spectra |
| [`BYOST.visualize`](visualize.md) | Plot building blocks, GPR surfaces, and templates |

Most users import from the top-level package:

```python
import BYOST
from BYOST import make_buildingblock, get_template, plot_template
```

See the [Quick Guide](../BYOST_quick_guide.ipynb) for workflow examples.