> ## 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.

# Write an SMS Autoresponder

> Build a keyword-based SMS autoresponder for automated replies

## Overview

This guide shows how to write an autoresponder for SMS text messages. Autoresponders can streamline marketing campaigns and subscription signups and reduce the amount of work humans have to do.

You can create an autoresponder 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 set up an SMS autoresponder.

    <h2 id="api-{{'Outline' | slugify}}">How it works</h2>

    <Frame>
      <img src="https://mintcdn.com/plivo/sqGJ0ONkT5kTuesy/images/sms-autoresponder.png?fit=max&auto=format&n=sqGJ0ONkT5kTuesy&q=85&s=efe5ae0859d2a62184abc7a876bec19e" alt="Outbound-SMS Flow" width="1446" height="774" data-path="images/sms-autoresponder.png" />
    </Frame>

    <h2 id="api-{{'Outline' | slugify}}">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.

    <h2 id="api-{{'Create the autoresponder application using Spring' | slugify}}">Create the autoresponder application using Spring</h2>

    Edit the PlivoSmsApplication.java file in the src/main/java/com.example.demo/ folder and paste into it this code.

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

    import com.plivo.api.exceptions.PlivoValidationException;
    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.PostMapping;

    @SpringBootApplication
    public class PlivoSmsApplication {

    	public static void main(String[] args) {
    		SpringApplication.run(PlivoSmsApplication.class, args);
    	}
    	
    	@PostMapping(value = "/autoresponder/", produces = {"text/xml"})
    	public String postBody(String From, String To, String Text) throws PlivoXmlException, PlivoValidationException {
    		String body;
    		if (Text.toLowerCase() == "interested") {
    			body = "Thank you for showing interest. One of our agents will contact you.";
    		}
    		else{
    			body = "Reply 'Interested' to connect with our agents";
    		}
    		Response response = new Response().children(
    				new Message(To,From,body));
    		return response.toXmlString();
    	}

    }
    ```

    Save the file and run it.

    You should see your basic server application in action at [http://localhost:8080/autoresponder/](http://localhost:8080/autoresponder/).

    Set up ngrok to expose your local server to the internet.

    <h2 id="api-create-a-plivo-application-for-autoresponder">Create a Plivo application for the autoresponder</h2>

    Associate the controller you created with Plivo by creating a Plivo application. Visit 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 `Autoresponder`. Enter the server URL you want to use (for example `https://<yourdomain>.com/autoresponder/`) 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/EvRfP72Bjs4tuRt5/images/create-app-autoresponder.png?fit=max&auto=format&n=EvRfP72Bjs4tuRt5&q=85&s=7f9aa51d5cbdd884072e6a53b53df53e" alt="Create Application" width="2874" height="1574" data-path="images/create-app-autoresponder.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 `Autoresponder` (the name we gave the application).

    Click **Update Number** to save.

    <Frame>
      <img src="https://mintcdn.com/plivo/NFI9_HRHTMInDf93/images/assign-app-autoresponder.png?fit=max&auto=format&n=NFI9_HRHTMInDf93&q=85&s=904f86e58fe21b0df89043205e9c74c6" alt="Assign Phone Number to Plivo Number" width="2870" height="1574" data-path="images/assign-app-autoresponder.png" />
    </Frame>

    <h2 id="Test">Test</h2>
    Send a text message to the Plivo number you specified using any phone.
  </Tab>
</Tabs>