> ## Documentation Index
> Fetch the complete documentation index at: https://plivo.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Reply to Incoming SMS

> Receive and send automated replies to incoming SMS text messages

## Overview

This guide shows how to receive SMS text messages on a Plivo phone number — something you might want to do to acknowledge a request from a customer, handle opt-ins and opt-outs, or implement an autoresponder application.

You can reply to SMS messages either by using our PHLO visual workflow builder or our APIs. Follow the instructions in one of the tabs below.

<Tabs>
  <Tab title="Using API">
    Here’s how to use Plivo APIs to reply to incoming SMS text messages.

    <h2 id="api-prerequisites">Prerequisites</h2>

    To get started, you need a Plivo account —  [sign up](https://cx.plivo.com/signup) with your work email address if you don’t have one already. To receive incoming messages, you must have a Plivo phone number that supports SMS; you can rent numbers from the [Numbers](https://cx.plivo.com/phone-numbers) page of the Plivo console or by using the [Numbers API](/docs/numbers/). If this is your first time using Plivo APIs, follow our instructions to set up a Java development environment and a web server and safely expose that server to the internet.

    <h2 id="api-create-a-spring-application-to-reply-to-messages">Create a Spring application to reply to messages</h2>

    Use [Spring Initializr](https://start.spring.io/) to create a boilerplate project called `Plivo SMS`. Open the file `PlivoSmsApplication` and paste into it this code.

    ```java theme={null}
    package com.example.Plivo.SMS;

    import com.plivo.api.exceptions.PlivoXmlException;
    import com.plivo.api.xml.Message;
    import com.plivo.api.xml.Response;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RestController;

    @RestController
    @SpringBootApplication
    public class PlivoSmsApplication {

    	public static void main(String[] args) {
    		SpringApplication.run(PlivoSmsApplication.class, args);
    	}
    	
    	@GetMapping(value = "/replysms/", produces = {"application/xml"})
    	public String getBody(String From, String To, String Text) throws PlivoXmlException {
    		System.out.println(From + " " + To + " " + Text);
    		Response res = new Response().children(
    				new Message(To, From, "Thank you, we received your request"));
    		return res.toXmlString();
    	}

    }
    ```

    Expose your local server to the internet.

    <h2 id="api-create-a-plivo-application-to-reply-to-messages">Create a Plivo application to reply to messages</h2>

    Associate the Spring application you created with Plivo by creating a Plivo application. Visiting Messaging > [Applications](https://cx.plivo.com/xml-applications) and click **Add New Application**. You can also use Plivo's [Application API](/docs/account/api/application/#create-an-application).

    Give your application a name — we called ours `Reply Incoming SMS`. Enter the server URL you want to use (for example `http://<yourdomain>.com/replysms/`) in the `Message URL` field and set the method to `POST`. Click **Create Application** to save your application.

    <Frame>
      <img src="https://mintcdn.com/plivo/2OFvQXVNT3srKLUy/images/create_reply_sms.png?fit=max&auto=format&n=2OFvQXVNT3srKLUy&q=85&s=0371a975aa748267124e9ea9debc7a0f" alt="Create Application" width="1440" height="822" data-path="images/create_reply_sms.png" />
    </Frame>

    <h2 id="api-assign-a-plivo-number-to-your-application">Assign a Plivo number to your application</h2>

    Navigate to the [Numbers](https://cx.plivo.com/phone-numbers) page and select the phone number you want to use for this application.

    From the Application Type drop-down, select `XML Application`.

    From the Plivo Application drop-down, select `Reply Incoming SMS` (the name we gave the application).

    Click **Update Number** to save.

    <Frame>
      <img src="https://mintcdn.com/plivo/NFI9_HRHTMInDf93/images/assign_reply_incoming_sms.png?fit=max&auto=format&n=NFI9_HRHTMInDf93&q=85&s=7f440f6a930c41f1f3393744857b50c3" alt="Assign Phone Number to Reply SMS App" width="1440" height="821" data-path="images/assign_reply_incoming_sms.png" />
    </Frame>

    <h2 id="api-test">Test</h2>

    Send a text message to the Plivo number you specified using any phone. You should receive a reply.
  </Tab>
</Tabs>