---
title: Overview
date: 2026-06-28T22:15:00+01:00
author: John Henry Donovan
canonical_url: "https://johnhenry.ie/plugins/bundle-builder/docs/getting-started/overview"
section: Plugins
---
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Documentation

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# Overview

**Bundle Builder** lets you group several Craft Commerce products into one purchasable **bundle**. It adds to the cart as **one line item** at **one price**, while the customer still picks a variant for each component at checkout.

## What it does

- Editors set up **bundle types** first (each with its own field layout, SKU/description formats, URL settings and tax treatment), then create **bundles** under them, all through Craft's native element editor.
- A bundle references one or more **products**, each with a quantity. The customer picks the **variant** for each product when adding to the cart.
- Pricing is either **fixed** or **automatic** (the components' total minus a discount, kept in sync as component prices move).
- Availability is gated by each component's stock, and once an order completes, each chosen variant's inventory comes down.
- Tax follows the composite-vs-multiple-supply distinction common to VAT, GST and sales-tax regimes: **composite** (single rate) or **multiple** (apportioned per component).

## How it works under the hood

A bundle is a `Bundle` element extending `craft\commerce\base\Purchasable`: a real purchasable with its own SKU, base price, tax/shipping category and snapshot. It doesn't track its own inventory; instead:

- `getIsAvailable()` checks the post/expiry window and that every component has an in-stock variant.
- On add-to-cart, the chosen variants are checked and written to the line item as **readable options** plus a machine-readable **snapshot**.
- On order completion, that snapshot drives the **inventory decrement** of each component variant.
- For *multiple supply* bundles, a custom tax adjuster splits the tax across components, against whatever tax rates and zones are set up in Commerce: VAT, GST, sales tax, or otherwise.

## Next

- [Installation](https://johnhenry.ie/plugins/bundle-builder/docs/getting-started/installation)
- [Bundle types](https://johnhenry.ie/plugins/bundle-builder/docs/getting-started/bundle-types)
- [Creating bundles](https://johnhenry.ie/plugins/bundle-builder/docs/guide/creating-bundles)
- [Tax treatment](https://johnhenry.ie/plugins/bundle-builder/docs/guide/tax-treatment)

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