Go SDK

sumup-go(Opens in a new tab) is the official Go module. It exposes typed clients for every endpoint, handles authentication headers, and surfaces helpers for common request payloads.

Installation

Install the module with go get github.com/sumup/sumup-go (or go install for reproducible builds).

Configure Authentication

Create a secret API key or OAuth access token in the developer dashboard(Opens in a new tab). The SDK reads SUMUP_API_KEY by default, so setting SUMUP_API_KEY=sup_sk_MvxmLOl0... before running your binary is enough. You can also pass the key explicitly:

client := sumup.NewClient(client.WithAPIKey("sup_sk_MvxmLOl0..."))

Examples

Online Payment Checkout

package main

import (
  "context"
  "fmt"
  "log"
  "os"

  sumup "github.com/sumup/sumup-go"
)

func main() {
  ctx := context.Background()
  client := sumup.NewClient()

  merchantCode := os.Getenv("SUMUP_MERCHANT_CODE")
  desc := "Online payment via card widget"

  checkout, err := client.Checkouts.Create(ctx, sumup.CheckoutsCreateParams{
    Amount:            25.00,
    CheckoutReference: "ORDER-1001",
    Currency:          sumup.CurrencyEUR,
    Description:       &desc,
    MerchantCode:      merchantCode,
  })
  if err != nil {
    log.Fatalf("create checkout: %v", err)
  }

  fmt.Println(*checkout.ID)
  // Return checkout ID to your webpage so the SumUp card widget can complete the payment.
}

Cloud API Checkout

package main

import (
  "context"
  "fmt"
  "log"
  "os"
  "strings"
  "time"

  sumup "github.com/sumup/sumup-go"
)

func main() {
  ctx := context.Background()
  client := sumup.NewClient()

  merchantCode := os.Getenv("SUMUP_MERCHANT_CODE")
  affiliateKey := os.Getenv("SUMUP_AFFILIATE_KEY")
  appID := os.Getenv("SUMUP_APP_ID")

  readerList, err := client.Readers.List(ctx, merchantCode)
  if err != nil {
    log.Fatalf("list readers: %v", err)
  }

  var solo sumup.Reader
  for _, rdr := range readerList.Items {
    if strings.EqualFold(string(rdr.Device.Model), "solo") {
      solo = rdr
      break
    }
  }
  if solo.ID == "" {
    log.Fatal("Pair a Solo reader before using the Cloud API.")
  }

  checkout, err := client.Readers.CreateCheckout(ctx, merchantCode, string(solo.ID), sumup.CreateCheckoutRequest{
    TotalAmount: sumup.CreateCheckoutRequestTotalAmount{
      Currency: "EUR",
      MinorUnit: 2,
      Value:    1500,
    },
  })
  if err != nil {
    log.Fatalf("create checkout: %v", err)
  }

  fmt.Println(checkout.Data.ClientTransactionId)
}