Can one product be locked for purchase with upsells on Shopify?

Topic summary

A user is asking whether Shopify allows locking customers into purchasing a single core product from a collection while still enabling them to add upsells during checkout.

Key Question:

  • Can a mandatory base product be enforced with optional add-ons/upsells?

Current Status:

  • No responses or solutions have been provided yet
  • The inquiry remains unanswered

Technical Context:

  • This likely involves customizing the checkout flow or cart behavior
  • May require modifications using JavaScript, HTML/CSS, or Shopify’s cart API
  • Could relate to product bundling or conditional purchase logic
Summarized with AI on November 12. AI used: claude-sonnet-4-5-20250929.

Is there a way in Shopify when your client purchases a product on our website but we want to lock them into 1 core product only in a collection but they can add more upsells?