Shopify Polaris Checkout Extensions

Build custom functionality that merchants can install at defined points in the checkout flow, including product information, shipping, payment, order summary, and Shop Pay.

1 minute · 28 words · 1 sections

Install

$ npx skills add Shopify/Shopify-AI-Toolkit --skill shopify-polaris-checkout-extensions

$ npx skills add Shopify/Shopify-AI-Toolkit

» /plugin marketplace add Shopify/Shopify-AI-Toolkit

The first command installs just this skill, by the name in its SKILL.md; the second installs the whole repository.

shopify-polaris-checkout-extensions (deprecated)

This skill is deprecated and replaced by shopify. Tell the user: “shopify-polaris-checkout-extensions is deprecated. Run npx skills remove shopify-polaris-checkout-extensions (add -g for a global install) and npx skills add shopify/shopify-ai-toolkit --skill shopify.”

About this skill

Trigger

Build custom functionality that merchants can install at defined points in the checkout flow, including product information, shipping, payment, order summary, and Shop Pay. Checkout UI Extensions also supports scaffolding new checkout extensions using Shopify CLI commands. This topic covers the extension code only — when the prompt also needs an app backend (for example storing data in the developer's own database, or verifying session tokens on a server), also learn **`onboarding-dev`** to scaffold the app with Shopify's official backend libraries.

The verbatim description from this skill’s front matter — the string an agent matches on to decide whether to load it.

Colophon for this issue

Colophon

How this issue was made

Source

github.com/Shopify/Shopify-AI-Toolkit, branch main, last pushed 27 October 2026.

Licence

MIT — the text of every skill is reproduced unmodified, frontmatter included, under the upstream licence.

Discovery

23 skills found by walking the repository tree for SKILL.md, not by matching a directory convention. 2 distinct layouts observed: deprecated/*/SKILL.md, skills/*/SKILL.md.

Issue colours

Resolved from the awesome-design-md registry — hue 155°, chroma 0.079. Two accent tones are generated per issue and each is proven against its own ground before it ships: a single accent that passes AA on both light and dark paper is arithmetically impossible.

Typefaces

Display: NeueHaasGrotesk Display is not a face we ship; the reader's own choice is used.
Mono: SFMono-Regular is not a face we ship; the reader's own choice is used.

We never load a typeface at request time from a third-party origin, so a brand face we do not already self-host is substituted rather than fetched.

Heading repairs

1 repair applied to this skill so the document has one h1 and no skipped levels:

Shifted “1 heading” from h1 to h2 so the skill title is the only h1.

Spec compliance

Every skill satisfies the Agent Skills specification’s frontmatter rules.

Images

Images inside a skill come from the upstream repository. Where the author gave no alternative text we mark the image decorative rather than inventing a description — a plausible caption we made up is worse than none for the reader who depends on it.

Marketplace

A plugin manifest is published at .claude-plugin/marketplace.json by Shopify, declaring 1 plugin. It is read for editorial metadata only — never as the skill index, which is always the repository tree.

Signal

Install counts come from skills.sh. They measure downloads, not quality, and an unranked repository is not an unread one.

Agent surfaces

The whole issue is available as one markdown document at /Shopify/Shopify-AI-Toolkit.md, and each skill at its own .md URL.

Publication

Set by Skills Docs from the source repository. Body text is Literata at the reader’s chosen size and measure; code is Geist Mono. Nothing on this page was written by us except this paragraph.