> ## 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.

# Send usage event

> This endpoint is used for transmitting usage measurement events to either a designated customer or a specific subscription.

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

  curl --location --request POST "$LAGO_URL/api/v1/events" \
  --header "Authorization: Bearer $API_KEY" \
  --header 'Content-Type: application/json' \
  --data-raw '{
        "event": {
            "transaction_id": "__UNIQUE_ID__",
            "external_subscription_id": "__YOUR_SUBSCRIPTION_ID__",
            "code": "__BILLABLE_METRIC_CODE__",
            "timestamp": $(date +%s),
            "properties": {
              "custom_field": 12
            }
        }
    }'
  ```

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

  client = Client(api_key='__YOUR_API_KEY__')

  event = Event(
    transaction_id="__UNIQUE_ID__",
    external_subscription_id="__UNIQUE_ID__",
    code="__BILLABLE_METRIC_CODE__",
    timestamp=1650893379,
    properties={"custom_field": "custom"}
  )

  try:
      client.events.create(event)
  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.events.create(
    transaction_id: "__UNIQUE_ID__",
    external_subscription_id: "__SUBSCRIPTION_ID__",
    code: "__BILLABLE_METRIC_CODE__",
    timestamp: Time.now.to_i,
    properties: {
        custom_field: 12
    }
  )
  ```

  ```js Javascript
  await client.events.createEvent({
    event: {
      transaction_id: "__UNIQUE_TRANSACTION_ID__",
      external_subscription_id: "__UNIQUE_SUBSCRIPTION_ID__",
      code: "__BILLABLE_METRIC_CODE__",
      timestamp: 1650893379,
      properties: { customField: "custom" },
    },
  });
  ```

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

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

  eventInput := &lago.EventInput{
      TransactionID: "__UNIQUE_TRANSACTION_ID__",
      ExternalSubscriptionID: "__UNIQUE_SUBSCRIPTION_ID__",
      Code:          "__BILLABLE_METRIC_CODE__",
      Timestamp:     time.Now().Unix(),
      Properties: map[string]string{
              "nbusers": "12",
          },
  }

  err := lagoClient.Event().Create(eventInput)
  if err != nil {
      // Error is *lago.Error
      panic(err)
  }
  }
  ```

  ```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 CreateEventExample
    {
        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 EventsApi(Configuration.Default);
            var eventInput = new EventInput(); // EventInput | Event payload

            try
            {
                // Create a new event
                apiInstance.CreateEvent(eventInput);
            }
            catch (ApiException e)
            {
                Debug.Print("Exception when calling EventsApi.CreateEvent: " + 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\EventsApi(
    // 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
  );
  $event_input = new \OpenAPI\Client\Model\EventInput(); // \OpenAPI\Client\Model\EventInput | Event payload

  try {
    $apiInstance->createEvent($event_input);
  } catch (Exception $e) {
    echo 'Exception when calling EventsApi->createEvent: ', $e->getMessage(), PHP_EOL;
  }
  ```
</RequestExample>