@letterpress/language

Framework-neutral CodeMirror 6 language services for Letterpress's versioned email/mjml-liquid@1, html/liquid@1, and text/liquid@1 profiles. The generated backend contract supplies profile and element metadata, completion vocabulary, and diagnostic codes. Pinned CodeMirror parsers and the Shopify Liquid formatter provide the browser implementation. The browser models a smaller advisory diagnostic set; publication still requires the Elixir compiler.

The MJML + Liquid formatter is lazy-loaded as a browser-only bundle. Consumers do not need to install Prettier or the Shopify formatter plugin.

The package supports its declared CodeMirror peer ranges. Newer Liquid peers also provide automatic percent-brace closing; older peers retain the language services without that optional enhancement.

See the repository README and public contract for the package boundary and backend guarantees.

import { letterpressLanguage } from "@letterpress/language"

const extension = letterpressLanguage({
  profile: "email/mjml-liquid@1",
  schema: {
    version: 1,
    variables: {
      name: { type: "string", context: "html_text" },
      action_url: { type: "url", context: "url" },
    },
  },
})

The package supplies mixed parsing, folding, indentation, completion, formatting, contract-aware local diagnostics, and stale-response filtering. Local diagnostics are authoring feedback; only the Hex compiler can approve a publication artifact.