Include localization support for POS UI extension templates

[vctrchu]

Resolves https://github.com/shop/issues-retail/issues/20278

DO NOT MERGE UNTIL 1/19/2026 / POS 10.19

Problem

POS extension templates (pos-action, pos-block, pos-smart-grid) did not include locale files or demonstrate i18n usage, making it unclear to developers how to internationalize their POS extensions. This was inconsistent with admin extension templates which fully demonstrate localization.

Solution

• Added locales folder structure with en.default.json.liquid and fr.json.liquid to all three POS templates
• Updated shopify.extension.toml.liquid to use name = "t:name" for locale-based extension naming
• Implemented i18n examples in all flavors (Preact, React, JavaScript):
  • Preact: shopify.i18n.translate()
  • React: i18n from useApi()
  • JavaScript: api.i18n.translate()
• Created appropriate locale keys for each template:
  • pos-action: "name", "welcome"
  • pos-block: "name", "welcome", "block_heading", "block_content", "open_action"
  • pos-smart-grid: "name", "tile_heading", "tile_subheading", "modal_heading", "welcome"

Testing

• dev cd cli
• pnpm shopify app generate extension --clone-url https://github.com/Shopify/extensions-templates#11-06-include_localization_support_for_pos_ui_extension_templates --path ./your-app-root

[vctrchu]

• Include localization support for POS UI extension templates #338 👈 (View in Graphite)
• main

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[aaronschubert0]

If we're shipping this in 2026-01 that doesn't support React, can we just leave those templates as is and solely focus on the Preact / JS variants instead?

[aaronschubert0]

@vctrchu just doubling checking does the CLI support non-english values here?

[vctrchu]

I want to believe so based on the assumption that other extensions such as admin-block, etc follow this pattern

[vctrchu]

Looks like its also publicly documented https://shopify.dev/docs/apps/build/app-extensions/configure-app-extensions#common-properties

[vctrchu]

@aaronschubert0 That works for me. I made this change before the fact I realized that the il8n was not properly exposed and now that we are patching it to 2025-10 and releasing it for 2026-01, it makes sense to only update the preact/js templates.