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. 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.

Because you install it once and use it with any model. Shopify Polaris Checkout Extensions is plain Markdown rather than provider-specific code, so the same skill runs on GPT-5, Claude, Gemini, Grok, or a local model — and you can switch model mid-chat without it breaking. TypingMind runs on your own API keys, so you pay providers directly instead of a per-seat subscription, and your skills and chats stay in your own storage.

Open Plugins → Skills → Install from GitHub in TypingMind and paste https://github.com/Shopify/Shopify-AI-Toolkit/tree/main/deprecated/shopify-polaris-checkout-extensions. TypingMind reads its SKILL.md and installs it as a skill you can enable per chat.

Any model you connect in TypingMind. AI skills are plain Markdown instructions rather than provider-specific code, so GPT, Claude, Gemini, Grok, and local models can all load this skill when a request matches it.

As many as you like. As long as a model supports skills, you can use Shopify Polaris Checkout Extensions with it — GPT, Claude, Gemini, Grok, DeepSeek, Mistral, Llama and more — all on TypingMind with your own API keys.

Yes. It is published on GitHub by Shopify under the MIT license. You only pay your own AI provider for the tokens you use.

An AI skill is a reusable instruction bundle that teaches an AI model how to do one specific task. It follows the open Agent Skills format: a SKILL.md file with a name and description, plus any scripts, templates or reference files the model may need. The model reads the instructions only when your request matches the skill, so an installed skill costs nothing until it is used.

A plugin or MCP server gives a model new tools to call — code that runs somewhere and returns a result. An AI skill gives the model knowledge and process instead: how to approach a task, which steps to follow, what good output looks like. Skills are plain Markdown, so they need no server, no API key and no runtime, and they work with any model.