go get github.com/team-telnyx/telnyx-go

import (
  "context"
  "fmt"
  "os"

  "github.com/team-telnyx/telnyx-go"
  "github.com/team-telnyx/telnyx-go/option"
)

client := telnyx.NewClient(
  option.WithAPIKey(os.Getenv("TELNYX_API_KEY")),
)

import "errors"

result, err := client.Messages.Send(ctx, params)
if err != nil {
  var apiErr *telnyx.Error
  if errors.As(err, &apiErr) {
    switch apiErr.StatusCode {
    case 422:
      fmt.Println("Validation error — check required fields and formats")
    case 429:
      // Rate limited — wait and retry with exponential backoff
      fmt.Println("Rate limited, retrying...")
    default:
      fmt.Printf("API error %d: %s\n", apiErr.StatusCode, apiErr.Error())
    }
  } else {
    fmt.Println("Network error — check connectivity and retry")
  }
}

	response, err := client.Messaging10dlc.GetEnum(context.Background(), telnyx.Messaging10dlcGetEnumParamsEndpointMno)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("%+v\n", response)

	response, err := client.Seti.GetBlackBoxTestResults(context.Background(), telnyx.SetiGetBlackBoxTestResultsParams{})
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("%+v\n", response.Data)