Get Started with Voice Alerts Using Go

    Overview

    This guide shows how to make voice calls to alert customers to critical issues that require immediate attention. You can play recorded audio when the call recipient answers or use text-to-speech. You can then take action based on a dialpad key they press in response. You can set different actions if the call is not answered, if the line is busy, or if you reach voicemail.

    You can send voice alerts either by using our PHLO visual workflow builder or our APIs and XML documents. Follow the instructions in one of the tabs below.

    To implement voice alerts use-case, you can create and deploy a PHLO with a few clicks on the PHLO canvas. PHLO also lets you visually construct your entire use-case. With PHLO, you only pay for calls you make/receive, and building with PHLO is free.

    Outline

    Implementation

    In this section, we will guide you to create a PHLO to implement voice alerts use-case.

    Prerequisites

    1. Create a Plivo Account(if you don’t have one already): You can sign up with your work email address and complete the phone verification step using your mobile number.
    2. Set up your Dotnet dev environment: To set up your dev environment in your .NET(C#) programming language, please refer to the instructions available in the Set up Your Dotnet Dev Environment section.
    3. Buy a Plivo number(optional): You must have a voice-enabled Plivo phone number if you are willing to receive incoming calls. You can purchase numbers from the Numbers section of your Plivo Console. It is also possible to purchase numbers using the Numbers API.

    Create the PHLO

    1. On the top navigation bar, click PHLO. The PHLO page will appear and display your existing PHLOs, if any exist. If this is your first PHLO, then the PHLO page will be empty.
    2. Click CREATE NEW PHLO to build a new PHLO.
    3. In the Choose your use-case window, click Build my own. The PHLO canvas will appear with the Start node. Note: The Start node is the starting point of any PHLO. You can choose between the four available trigger states of the Start node; Incoming SMS, Incoming Call, and API Request. For this PHLO, we will use the API Request trigger state.
    4. Click the Start node to open the Configurations tab, and then enter the information to retrieve from the HTTP Request payload. For example, this could be a list of numbers to call.
    5. Click Validate to save the configurations for the node.
    6. From the list of components on the left-hand side, drag and drop the Initiate Call component onto the canvas. This will add a Initiate call node onto the canvas.
    7. Connect the Start node with the Initiate Call node, using the API Request trigger state.
    8. Configure the Initiate Call node to select the From and To numbers from the Start node. Note:
      • Enter two curly brackets to view all available variables.
      • The values for the From and To numbers are picked from the HTTP Request Payload. Make sure to clearly define the variables in the Start node.
    9. Click Validate to save the configurations for the node.
    10. Similarly, create a node for the IVR Menu component and connect it to the Initiate Call node using the Answered trigger state.
    11. Click the IVR Menu node to open the Configurations tab.
    12. Configure the choices for the IVR Menu from the Configurations tab. In this example, we will select 1 and 2 as the allowed choices and enter a message to play to the user.
    13. Rename the IVR Menu node to Gather_Input. Note: You can rename the nodes as per your requirements. We are using specific names to help you relate to the different nodes used in this use case.
    14. Enter a message in the Speak Text field. The caller will be greeted with this message. Note: You can also configure the Language and Voice for the message.
    15. Click Validate to to save the configurations of the node.
    16. Similarly, create three nodes for the Play Audio component. Note: In this example, we will need three Play Audio nodes; one node for each option (Wrong Input, 1, and 2).
    17. Rename these nodes to Invalid_Input_Prompt, Resolved_Prompt, and** Escalation_Prompt** using the Configurations tab.
    18. Connect Invalid_Input_Prompt node to the Gather_Input using the Wrong Input trigger state.
    19. Connect the Prompt Completed trigger state of Invalid_Input_Prompt node to the IVR Menu. This will send the user back to the IVR Menu if they press an incorrect option, or if they do not press any key.
    20. Connect Resolved_Prompt and Escalation_Prompt nodes to the Gather_Input using the 1 and 2 trigger states.
    21. Next, configure the Play Audio nodes to play a specific message to the user. Note: The audio playback can either be static or dynamic. In this example, we will use a combination of a static message along with some dynamic message for the Resolved_Prompt and Escalation_Prompt nodes.
    22. On the Play Audio Configurations tab, enter a static message (For example, Your Database status is: ) in the Speak Text field, followed by a variable to include the dynamic text. Note: You can choose a variable by entering two curly brackets in the Speak Text field.
    23. Click Validate to save the configurations for the node.
    24. Configure** Resolved_Prompt** and Escalation_Prompt nodes to speak a fixed message in case of a wrong input or no input.
    25. Click Validate to save the configurations for the node.
    26. Next, create a node for Initiate Call component and rename it to Escalation_Call.
    27. Connect the Escalation_Prompt node to the Escalation_Call node using the Prompt Completed trigger state. This will call a second phone number and announce the alert. You can set up any number of escalation numbers by creating similar nodes for each phone number.
    28. Connect the Escalation_Call node back to the Escalation_Prompt node using the Answered trigger state. This will play the same prompt to the second user and the process will repeat.
    29. After you complete the configurations, click Save. You can trigger your PHLO using the PHLO URL to test it out. Your complete PHLO will look like this:

    Voice Alert

    Set up Your Go Dev Environment

    You must set up and install Go and Plivo’s Go SDK to implement voice alerts use-case. Here’s how.

    Install Go

    You can install Go from the Official Installer.

    Install Plivo Go Package

    • Create a project directory, run the following command:

      $ mkdir mygoapp
      
    • Change the directory to our project directory in the command line:

      $ cd mygoapp
      
    • You can install the Plivo Go package using the go command.

      $ go get github.com/plivo/plivo-go
      
    • You can also install by cloning this repository into your GOPATH.

    Trigger the PHLO

    Once you have created and configured your PHLO, copy the PHLO_ID from here. You can integrate a PHLO into your application workflow by making an API request to trigger the PHLO with the required payload.

    With Static Payload

    Once you have created and setup your Go dev envrironment, you can go to your Plivo Consolse and copy the PHLO_ID. You can integrate a PHLO into your application workflow by making an API request to trigger the PHLO with the required payload.

    Note: When you configure the params while creating the PHLO, the values are hardcoded, and they act as static payload.

    With Static Payload

    Code

    Now, create a file called TriggerPhlo.go and paste the following code:

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    package main
    
    import (
    	"fmt"
    	"plivo-go"
    )
    // Initialize the following params with corresponding values to trigger resources
    const authId = "auth_id"
    const authToken = "auth_token"
    const phloId = "phlo_id"
    
    func main() {
    	testPhloRunWithoutParams()
    }
    
    func testPhloRunWithoutParams() {
    	phloClient, err := plivo.NewPhloClient(authId, authToken, &plivo.ClientOptions{})
    	if err != nil {
    			fmt.Print("Error", err.Error())
    			return
    		}
    	phloGet, err := phloClient.Phlos.Get(phloId)
    	if err != nil {
    			fmt.Print("Error", err.Error())
    			return
    		}
    	response, err := phloGet.Run(nil)
    	if err != nil {
    			fmt.Print("Error", err.Error())
    			return
    		}
    	fmt.Printf("Response: %#v\n", response)
    }
    

    With Dynamic Payload

    To use dynamic values for the parameters, you can use the liquid templating params while creating the PHLO and pass the values while triggering the PHLO.

    With Dynamic Payload

    Code

    Now, create a file called TriggerPhlo.go and paste the following code:

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    package main
    
    import (
    	"fmt"
    	"plivo-go"
    )
    // Initialize the following params with corresponding values to trigger resources
    const authId = "auth_id"
    const authToken = "auth_token"
    const phloId = "phlo_id"
    
    func main() {
    	testPhloRunWithParams()
    }
    
    func testPhloRunWithParams() {
    	phloClient, err := plivo.NewPhloClient(authId, authToken, &plivo.ClientOptions{})
    	if err != nil {
    			fmt.Print("Error", err.Error())
    			return
    		}
    	phloGet, err := phloClient.Phlos.Get(phloId)
    	if err != nil {
    			fmt.Print("Error", err.Error())
    			return
    		}
    	//pass corresponding from and to values
    	type params map[string]interface{}
    	response, err := phloGet.Run(params{
    		"from": "+14157778888",
    		"to":   "+14157778889",
    	})
    
    	if err != nil {
    		println(err)
    	}
    	fmt.Printf("Response: %#v\n", response)
    }
    

    You can get your Auth_ID and Auth_token from your dashboard AUTHID

    You can find the PHLO_ID on the PHLO Listing page. PHLO Listing

    Test and Validate

    You can save the file and use the below command to run it.

    go run TriggerPhlo.go
    
    Note: If you are using a Plivo Trial account for this example, you can only make calls to phone numbers that have been verified with Plivo. Phone numbers can be verified at the Sandbox Numbers page.

    Here’s how to use Plivo APIs and XML to implement voice alerts.

    How it works

    Outbound Call Flow

    Plivo requests an answer URL when the call is answered (step 4) and expects the file at that address to hold a valid XML response from the application with instructions on how to handle the call. To see how this works, you can use https://s3.amazonaws.com/static.plivo.com/answer.xml as an answer URL to test your first outgoing call. The file contains this XML code:

    <Response> 
    <Speak>Your database is out of memory. Press 1 to resolve or 2 to escalate.</Speak> 
    </Response>
    

    This code instructs Plivo to say, “Your database is out of memory. Press 1 to resolve or 2 to escalate” to the callrecipient. You can find the entire list of valid Plivo XML verbs in our XML Reference documentation.

    Prerequisites

    To get started, you need a Plivo account — sign up with your work email address if you don’t have one already. If this is your first time using Plivo APIs, follow our instructions to set up a Go development environment.

    Create a voice alerts application in Go

    Create a file called MakeCall.go and paste into it this code.

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    package main
    
    import "fmt"
    import "github.com/plivo/plivo-go"
    
    func main() {
    	client, err := plivo.NewClient("<auth_id>","<auth_token>", &plivo.ClientOptions{})
    	if err != nil {
    			fmt.Print("Error", err.Error())
    			return
    		}
    	response, err := client.Calls.Create(
    		plivo.CallCreateParams{
    			From: "<caller_id>",
    			To: "<destination_number>",
    			AnswerURL: "https://s3.amazonaws.com/static.plivo.com/alert.xml",
    			AnswerMethod: "GET",
    		},
    	)
    	if err != nil {
    			fmt.Print("Error", err.Error())
    			return
    		}
    	fmt.Printf("Response: %#v\n", response)
    }
    

    Replace the auth placeholders with your authentication credentials from the Plivo console. Replace the phone number placeholders with actual phone numbers in E.164 format (for example, +12025551234).

    Note: We recommend that you store your credentials in the auth_id and auth_token environment variables, to avoid the possibility of accidentally committing them to source control. If you do this, you can initialize the client with no arguments and Plivo will automatically fetch the values from the environment variables. You can use the os.Setenv and os.Getenv functions to store environment variables and fetch them when initializing the client.

    Test

    Save the file and run it.

    go run MakeCall.go
    
    Note: If you’re using a Plivo Trial account, you can make calls only to phone numbers that have been verified with Plivo. You can verify (sandbox) a number by going to the console’s Phone Numbers > Sandbox Numbers page.