> ## Documentation Index
> Fetch the complete documentation index at: https://lago-ftr-wallet-improvements.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Apply a coupon

> This endpoint is used to apply a specific coupon to a customer, before or during a subscription.

<RequestExample>
  ```bash cURL
  LAGO_URL="https://api.getlago.com"
  API_KEY="__YOUR_API_KEY__"

  curl --location --request POST "$LAGO_URL/api/v1/applied_coupons" \
    --header "Authorization: Bearer $API_KEY" \
    --header 'Content-Type: application/json' \
    --data-raw '{
      "applied_coupon": {
        "external_customer_id": "5eb02857-a71e-4ea2-bcf9-57d3a41bc6ba",
        "coupon_code": "startup_deal",
        "amount_cents": 2500,
        "amount_currency": "EUR",
        "frequency": "recurring",
        "frequency_duration": 3
      }
    }'
  ```

  ```python Python
  from lago_python_client.client import Client
  from lago_python_client.exceptions import LagoApiError
  from lago_python_client.models import AppliedCoupon

  client = Client(api_key='__YOUR_API_KEY__')

  applied_coupon = AppliedCoupon(
    external_customer_id="5eb02857-a71e-4ea2-bcf9-57d8885990ba",
    coupon_code="startup_deal",
    amount_cents=2500,
    amount_currency="EUR",
    frequency="recurring",
    frequency_duration=3
  )

  try:
      client.applied_coupons.create(applied_coupon)
  except LagoApiError as e:
      repair_broken_state(e)  # do something on error or raise your own exception
  ```

  ```ruby Ruby
  require 'lago-ruby-client'

  client = Lago::Api::Client.new({api_key: '__YOUR_API_KEY__'})

  client.applied_coupons.create(
    external_customer_id: "5eb02857-a71e-4ea2-bcf9-57d3a41bc6ba",
    coupon_code: "startup_deal",
    amount_cents: 2500,
    amount_currency: "EUR",
    frequency: "recurring",
    frequency_duration: 3
  )
  ```

  ```js Javascript
  const appliedCouponObject = {
    external_customer_id: "5eb02857-a71e-4ea2-bcf9-57d8885990ba",
    coupon_code: "startup_deal",
    amount_cents: 2500,
    amount_currency: "EUR",
    frequency: "recurring" as AppliedCouponObject["frequency"],
    frequency_duration: 3,
  };

  await client.appliedCoupons.applyCoupon({
    appliedCoupon: appliedCouponObject,
  });
  ```

  ```go Go
  import "fmt"
  import "github.com/getlago/lago-go-client"

  func main() {
  lagoClient := lago.New().
      SetApiKey("__YOUR_API_KEY__")

  applyCouponInput := &lago.ApplyCouponInput{
      ExternalCustomerID: "5eb02857-a71e-4ea2-bcf9-57d8885990ba",
      CouponCode: "startup_deal",
      Frequency: lago.CouponFrequencyRecurring,
      FrequencyDuration: 3
  }

  appliedCoupon, err := lagoClient.Coupon().ApplyToCustomer(applyCouponInput)
  if err != nil {
      // Error is *lago.Error
      panic(err)
  }

  // appliedCoupon is *lago.AppliedCoupon
  fmt.Println(appliedCoupon)
  }
  ```

  ```csharp C#
  using System.Collections.Generic;
  using System.Diagnostics;
  using Org.OpenAPITools.Api;
  using Org.OpenAPITools.Client;
  using Org.OpenAPITools.Model;

  namespace Example
  {
    public class ApplyCouponExample
    {
        public static void Main()
        {
            Configuration.Default.BasePath = "https://api.getlago.com/api/v1";
            // Configure HTTP bearer authorization: bearerAuth
            Configuration.Default.AccessToken = "YOUR_ACCESS_TOKEN";

            var apiInstance = new CouponsApi(Configuration.Default);
            var appliedCouponInput = new AppliedCouponInput(); // AppliedCouponInput | Apply coupon payload

            try
            {
                // Apply a coupon to a customer
                AppliedCoupon result = apiInstance.ApplyCoupon(appliedCouponInput);
                Debug.WriteLine(result);
            }
            catch (ApiException e)
            {
                Debug.Print("Exception when calling CouponsApi.ApplyCoupon: " + e.Message );
                Debug.Print("Status Code: "+ e.ErrorCode);
                Debug.Print(e.StackTrace);
            }
        }
    }
  }
  ```

  ```php PHP
  <?php
  require_once(__DIR__ . '/vendor/autoload.php');


  // Configure Bearer authorization: bearerAuth
  $config = OpenAPI\Client\Configuration::getDefaultConfiguration()->setAccessToken('YOUR_ACCESS_TOKEN');


  $apiInstance = new OpenAPI\Client\Api\CouponsApi(
    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
    // This is optional, `GuzzleHttp\Client` will be used as default.
    new GuzzleHttp\Client(),
    $config
  );
  $applied_coupon_input = new \OpenAPI\Client\Model\AppliedCouponInput(); // \OpenAPI\Client\Model\AppliedCouponInput | Apply coupon payload

  try {
    $result = $apiInstance->applyCoupon($applied_coupon_input);
    print_r($result);
  } catch (Exception $e) {
    echo 'Exception when calling CouponsApi->applyCoupon: ', $e->getMessage(), PHP_EOL;
  }
  ```
</RequestExample>