> For the complete documentation index, see [llms.txt](https://docs.gobtcpay.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.gobtcpay.com/api-reference/wallet-api/gobtc-pay-wallet-api/paying-at-a-pos.md).

# Paying at a POS

When the user scans the QR code shown on a merchant's POS terminal:

1. Call **Get payment** with the payment id from the QR code, and show the user the payment details (amount, merchant, expiry).
2. Call **Build payment transaction** with that payment. The response returns a `psbtBase64` — the unsigned transaction. Present it so the user can review what they are signing.
3. The user signs the PSBT with their key. Submit the signed transaction via **Settle payment** to complete the payment.

```mermaid
sequenceDiagram
  participant U as User
  participant W as Wallet app
  participant G as Gateway
  participant P as POS terminal
  P-->>U: show payment QR
  U->>W: scan QR (paymentId)
  W->>G: Get payment (paymentId)
  G-->>W: payment details
  W->>U: show amount & merchant
  W->>G: Build payment transaction (paymentId)
  G-->>W: psbtBase64
  W->>U: review & sign
  W->>G: Settle payment (signed PSBT)
  G-->>W: paymentTxId
```

***

This is the **Wallet** surface of the GoBTC Pay API. Backwards compatibility is preserved across published versions.

Found an error in the docs? Email <support@gomining.com>.


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