Shopify Custom Data

If you're building a Shopify app that needs to store custom data beyond the standard product, customer, or order fields, this is your starting point. It walks you through the proper workflow: defining metafields and metaobjects in TOML (which is version controlled and auto-installed), writing values via the Admin API, then reading them back. The guidance is opinionated and strict about avoiding GraphQL definition mutations unless you absolutely need runtime configuration. It also covers the tricky bits like app-owned namespace syntax ($app:type) and accessing metafields in checkout extensions without network calls. Written for app developers, not merchants using the Shopify admin.