Go SDK

sumup-go 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. 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().WithAuth("sup_sk_MvxmLOl0...")

Examples

Online payment checkout

package main

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

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

func main() {
  ctx := context.Background()
  client := sumup.NewClient().WithAuth(os.Getenv("SUMUP_API_KEY"))

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

  checkout, err := client.Checkouts.Create(ctx, sumup.CreateCheckoutBody{
    Amount:           25.00,
    CheckoutReference: "ORDER-1001",
    Currency:         shared.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.
}

Solo Cloud API checkout

package main

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

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

func main() {
  ctx := context.Background()
  client := sumup.NewClient().WithAuth(os.Getenv("SUMUP_API_KEY"))

  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 readers.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.")
  }

  description := "Solo Cloud API checkout"
  body := readers.CreateReaderCheckoutBody{
    Affiliate: &readers.CreateReaderCheckoutBodyAffiliate{
      AppId:               appID,
      ForeignTransactionId: fmt.Sprintf("solo-%d", time.Now().Unix()),
      Key:                 affiliateKey,
    },
    Description: &description,
    TotalAmount: readers.CreateReaderCheckoutBodyTotalAmount{
      Currency: "EUR",
      MinorUnit: 2,
      Value:    1500,
    },
  }

resp, err := client.Readers.CreateCheckout(ctx, merchantCode, string(solo.ID), body)
  if err != nil {
    log.Fatalf("create Solo checkout: %v", err)
  }

  fmt.Println(resp.Data.ClientTransactionId)
}