@polyxd/ds-govuk

@polyxd/ds-govuk

GOV.UK Frontend as a Polyxd design-system pack: DTCG 2025.10 token files that satisfy the semantic token contract.

npm run check -w @polyxd/ds-govuk     # contract check
npm run generate -w @polyxd/ds-govuk  # regenerate tokens/*.json

Source

govuk-frontend 6.5.1 (MIT). GOV.UK publishes compiled component CSS and no token file at all: its palette, functional colours, spacing points, measurements and type scale live in Sass settings, as maps. Those six settings files are vendored verbatim under scripts/sources/govuk, and the generator reads their maps directly — narrowly, by the shape of each map, rather than by evaluating Sass.

Names are kept: govuk.palette-blue-shade-25 for a palette colour, govuk.link or govuk.secondary-text for a functional one, govuk.spacing-4, govuk.font-size-19.

One mode

GOV.UK has one theme. There is no dark mode to read, and this pack does not invent one: it ships a single mode, and the theme compiler renders it whichever mode a surface asks for. A dark-mode surface in a GOV.UK pack is a light GOV.UK page, which is what GOV.UK is.

What GOV.UK doesn't have, and what the pack does

Contract token	GOV.UK	What the pack uses
radius.*	square corners, everywhere	0 — the one shape decision the whole system is built on
shadow.raised, shadow.overlay	no shadows at all	a zero, transparent shadow: depth is a border, not a blur
motion.duration.*	nothing animates	zero, rather than an invented curve
color.border.focus	a yellow block with a 4px black bar under it	the black bar — the yellow alone is 1.35:1 on the page, and a single-colour ring can't be both halves
color.status.warning.*	its warning component is black text beside a black icon	its orange, which the palette carries for exactly this weight of message
type.label.small	the scale stops at 16px	16px — GOV.UK has no small print, which is the point of the system

Where a role does have to move, it moves along GOV.UK's own variants of the same colour (primary, tint-25…tint-95, shade-25, shade-50), sorted by measured luminance. In 6.5.1 the only moves are in orange: orange-primary is 2.25:1 on white, so accents take orange-shade-25, and panel text takes orange-shade-50.

Files

File	What's in it
tokens/system.light.json	GOV.UK's palette, functional colours, spacing and type scale, plus the polyxd.sys.* additions
tokens/semantic.json	the Polyxd contract, each token an alias
manifest.json	the one mode, contract version, provenance
scripts/sources/govuk/	the vendored Sass settings and GOV.UK's licence

Logo

This pack has no logo file, on purpose. The crown and the GOV.UK logotype are protected: the GOV.UK Service Manual (Making your service look like GOV.UK) says a service that isn't on GOV.UK must not use them, nor the GDS Transport typeface, nor suggest it is an official government website. Wherever Polyxd lists this pack it sets the plain words GOV.UK Design System in its own type.

GOV.UK and the crown are protected marks of the UK Government, named here only to identify the design system this pack is modelled on. Polyxd is not affiliated with the Government Digital Service.