Sending SMS in Kotlin: sms-client-kotlin Library API |…

Sending SMS in Kotlin: sms-client-kotlin Library API

Modern mobile applications and server solutions often require integration with SMS gateways to send notifications, confirmations, or marketing messages. For the Kotlin language, there is a convenient library sms-client-kotlin that provides a simple and type-safe API for working with popular SMS providers. In this article, we will thoroughly examine its architecture, methods, and usage examples.

What is sms-client-kotlin?

The sms-client-kotlin library is a lightweight HTTP client written in pure Kotlin using coroutines. It abstracts working with the REST API of various SMS providers (e.g., Twilio, Vonage, SMS-Center) and provides a unified interface for sending messages. Key advantages:

Asynchrony — all requests are executed via Kotlin coroutines.
Type safety — strict typing of request and response parameters.
Modularity — support for multiple providers through a single SmsSender interface.
Easy setup — minimal number of dependencies.

Installation and Setup

To add the library to your project, use Gradle. Add the dependency to the build.gradle.kts file:

dependencies {    implementation("com.github.sms-client:sms-client-kotlin:1.2.0")    implementation("io.ktor:ktor-client-core:2.3.0")    implementation("io.ktor:ktor-client-cio:2.3.0") // or another engine}

After synchronizing the project, you can create a client instance. Example initialization for the Twilio provider:

import sms.client.SmsClientimport sms.client.provider.twilio.TwilioConfig

fun main() {    val config = TwilioConfig(        accountSid = "ACxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",        authToken = "your_auth_token_here",        fromNumber = "+1234567890"    )

    val client = SmsClient.create(config)}

Main API Methods

The library provides several key methods for sending and managing SMS:

1. Sending a Single Message

The sendSms method takes the recipient's number and the message text. It returns an SmsResult object with information about the sending.

suspend fun sendSingleMessage(client: SmsClient) {    val result = client.sendSms(        to = "+79876543210",        message = "Hello! This is a test message from Kotlin."    )

    when (result) {        is SmsResult.Success -> println("Sent! ID: ${result.messageId}")        is SmsResult.Failure -> println("Error: ${result.errorMessage}")    }}

2. Batch Sending

For mass mailing, use the sendBatch method. It takes a list of recipients and a common text (or individual messages).

suspend fun sendBatch(client: SmsClient) {    val recipients = listOf(        BatchRecipient("+79111111111", "10% discount on your first order!"),        BatchRecipient("+79222222222", "Your confirmation code: 1234")    )

    val batchResult = client.sendBatch(recipients)    println("Successfully sent: ${batchResult.successCount}, errors: ${batchResult.failureCount}")}

3. Checking Delivery Status

The getDeliveryStatus method allows you to get the current status of a previously sent message by its identifier.

suspend fun checkStatus(client: SmsClient, messageId: String) {    val status = client.getDeliveryStatus(messageId)    println("Status of message $messageId: ${status.status} (${status.description})")}