@voidbase-cloud/plugin-tax-flat

The flat-rate tax plugin of voidbase, as a package of its own. It provides tax@1: one percentage, VOIDBASE_TAX_RATE, on the order's subtotal, as one line labelled with the rate. Unset or zero is a shop that charges no tax, which is a valid shop and not an error.

It ships with voidbase and is on by default — @voidbase-cloud/voidbase depends on this package and loads it — so an instance needs nothing here. Install it yourself only to load it into an app that builds its own plugin graph.

The shape

• It is the default behind an interface, not the behaviour itself. commerce requires tax@1, not this plugin. A shop that owes VAT per country, or that has to call Avalara or TaxJar, installs something else that provides tax@1, and commerce never learns that anything changed.
• The rounding is the part worth reading. Amounts are integers in the currency's minor unit, and the rate is applied to the subtotal, half away from zero — rounding each line and adding them up is how a total ends up a penny away from what the customer was shown.
• It imports the core by name and only by name: @voidbase-cloud/voidbase/platform (the #platform/env pick, both conditions kept), /types, /interfaces, /kernel and /plugins. No new entry point.
• @voidbase-cloud/voidbase/plugins/tax-flat stays published forever, as a re-export of this package.

The rest of the shape — the lockstep version, the peer edge back on the core, hono declared at the core's own range, npm as the only registry this name is published to — is the template packages/plugin-realtime/README.md describes, and packages/voidbase/test/unit/plugin-extraction.test.ts asserts it over every @voidbase-cloud/plugin-* package in the workspace rather than over any one of them.

Licence

MIT, with voidbase.