Using custom payment methods from POS app with API

Technical Q&A

Topic summary

Topic: Using Shopify POS custom payment methods via API.

  • Users have enabled custom payment methods in the Shopify POS (point‑of‑sale) app per the Shopify Help Center article (section: “Activating custom payments for the Shopify POS app”).
  • Goal: Reflect those custom POS payments via the Shopify API, including specifying the payment gateway associated with the custom method.
  • Current capability found: The GraphQL mutation orderMarkAsPaid can mark an order as paid.
  • Gap: There is no clear way (from the thread or linked docs) to pass or record the custom payment method’s gateway information via the API, nor guidance on sending a POS custom payment for approval/acceptance.

Status: Unresolved. Documentation appears to lack details on mapping custom POS payments to API fields (e.g., gateway) and handling approval flows. Key questions remain open.

Summarized with AI on January 13. AI used: gpt-5.
2

Same question here, anyone got an answer to using Shopify POS Custom Payment, then sending it over API & accepting approval? It does not state in any docs