shopify-custom-data — Claude skill for Shopify Metafields
A Claude and Claude skill that walks the agent through Metafields and Metaobjects in Shopify apps.
npx skills add openai/plugins --skill shopify-custom-data -a codexWhat shopify-custom-data does
The skill kicks in when a prompt mentions Metafields or Metaobjects, and it fixes the order of work: definitions first, then writing values, then reading them. Definitions live in shopify.app.toml, so they are version controlled and installed automatically. Values are read and written through the GraphQL Admin or Storefront API afterwards.
Inside are the exact calls: metafieldsSet for metafields, metaobjectUpsert for metaobjects, reads with jsonValue and aliases. Checkout extensions get their own section on useAppMetafields, and Shopify Functions get a GraphQL input query. The skill insists on one approach and does not offer alternatives unless asked, which keeps the developer from juggling options.
Watch the namespaces. A metaobject declared as [metaobjects.app.example] is read as $app:example, not app. The author calls namespace: app a serious mistake, so check your queries. Node.js is required. For scaffolding apps and extensions the skill points to Shopify CLI only: shopify app init, shopify app generate extension, shopify app dev, shopify app deploy.
What it helps with
- declare a product metafield schema in
shopify.app.toml - write a metafield value with
metafieldsSet - create an author metaobject and link it to a product
- read a metafield in a checkout extension without a network call
- select metafields in a Shopify Functions GraphQL query
Example prompts for the agent
- Add a care_guide metafield for a product in shopify.app.toml
- Write the example metafield value for product gid://shopify/Product/1234
- Show how to read a metaobject of type $app:author in the Storefront API
How to install shopify-custom-data
1Skills CLI (Vercel)
npx skills add openai/plugins --skill shopify-custom-data -a codex2Manually: put the files in place
.agents/skills/shopify-custom-data/SKILL.mdFor all projects use ~/.agents/skills/
1Skills CLI (Vercel)
npx skills add openai/plugins --skill shopify-custom-data -a claude-code2Manually: put the files in place
~/.claude/skills/shopify-custom-data/SKILL.mdCopy the whole skill folder; for one project use .claude/skills/shopify-custom-data/
Manually: put the files in place
.cursor/skills/shopify-custom-data/SKILL.mdCursor also reads .agents/skills/ and .claude/skills/
1GitHub CLI
gh skill install openai/plugins shopify-custom-data2Manually: put the files in place
.github/skills/shopify-custom-data/SKILL.mdPlatform CLI
gemini skills install https://github.com/openai/plugins --path plugins/shopify/skills/shopify-custom-dataManually: put the files in place
.devin/skills/shopify-custom-data/SKILL.mdThe legacy .windsurf/skills/ path still works
Claude.ai
Zip the folder and upload it in Settings → Capabilities → Skills
Step by step, with commands for each platform: Codex skills: how to install, where they live, how to call them
Questions about shopify-custom-data
How do I install shopify-custom-data in Claude?
Run npx skills add openai/plugins --skill shopify-custom-data, then npx skills add openai/plugins --skill shopify-custom-data -a codex. The skill file lands at .agents/skills/shopify-custom-data/SKILL.md.
What does shopify-custom-data do?
It sets the agent's order of work for Metafields and Metaobjects: TOML definitions, value writes through the Admin API, reads through the Admin or Storefront API.
Does shopify-custom-data require Node.js?
Yes, Node.js is listed as a requirement. The skill also tells the agent to scaffold apps and extensions through Shopify CLI.
