Some products and features are in the process of being renamed. Generative playbook and flow features are also being migrated to a single consolidated console. See the details.

Create a webhook service

The prebuilt agent you created in the last step requires a webhook. Cloud Run functions are used to host the webhook in this tutorial due to their simplicity, but there are many other ways that you could host a webhook service. The example also uses the Go programming language, but you can use any language supported by Cloud Run functions.

Create the Function

Cloud Run functions can be created with the Google Cloud console (visit documentation, open console). To create a function for this tutorial:

It is important that your Dialogflow agent and the function are both in the same project. This is the easiest way for Dialogflow to have secure access to your function. Before creating the function, select your project from the Google Cloud console.

Go to project selector
Open the Cloud Run functions overview page.

Go to Cloud Run functions overview
Click Create Function, and set the following fields:
- Environment: 1st gen
- Function name: tutorial-telecommunications-webhook
- Region: If you specified a region for your agent, use the same region.
- HTTP Trigger type: HTTP
- URL: Click the copy button here and save the value. You will need this URL when configuring the webhook.
- Authentication: Require authentication
- Require HTTPS: checked
Click Save.
Click Next (You do not need special runtime, build, connections, or security settings).
Set the following fields:
- Runtime: Select the latest Go runtime.
- Source code: Inline Editor
- Entry point: HandleWebhookRequest

Replace the code with the following:

package cxtwh

import (
	"context"
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	"os"
	"strings"

	"cloud.google.com/go/spanner"
  "google.golang.org/grpc/codes"
)

// client is a Spanner client, created only once to avoid creation
// for every request.
// See: https://cloud.google.com/functions/docs/concepts/go-runtime#one-time_initialization
var client *spanner.Client

func init() {
	// If using a database, these environment variables will be set.
	pid := os.Getenv("PROJECT_ID")
	iid := os.Getenv("SPANNER_INSTANCE_ID")
	did := os.Getenv("SPANNER_DATABASE_ID")
	if pid != "" && iid != "" && did != "" {
		db := fmt.Sprintf("projects/%s/instances/%s/databases/%s",
			pid, iid, did)
		log.Printf("Creating Spanner client for %s", db)
		var err error
		// Use the background context when creating the client,
		// but use the request context for calls to the client.
		// See: https://cloud.google.com/functions/docs/concepts/go-runtime#contextcontext
		client, err = spanner.NewClient(context.Background(), db)
		if err != nil {
			log.Fatalf("spanner.NewClient: %v", err)
		}
	}
}

type fulfillmentInfo struct {
	Tag string `json:"tag"`
}

type sessionInfo struct {
	Session    string                 `json:"session"`
	Parameters map[string]interface{} `json:"parameters"`
}

type text struct {
	Text []string `json:"text"`
}

type responseMessage struct {
	Text text `json:"text"`
}

type fulfillmentResponse struct {
	Messages []responseMessage `json:"messages"`
}

// webhookRequest is used to unmarshal a WebhookRequest JSON object. Note that
// not all members need to be defined--just those that you need to process.
// As an alternative, you could use the types provided by the Dialogflow protocol buffers:
// https://pkg.go.dev/google.golang.org/genproto/googleapis/cloud/dialogflow/cx/v3#WebhookRequest
type webhookRequest struct {
	FulfillmentInfo fulfillmentInfo `json:"fulfillmentInfo"`
	SessionInfo     sessionInfo     `json:"sessionInfo"`
}

// webhookResponse is used to marshal a WebhookResponse JSON object. Note that
// not all members need to be defined--just those that you need to process.
// As an alternative, you could use the types provided by the Dialogflow protocol buffers:
// https://pkg.go.dev/google.golang.org/genproto/googleapis/cloud/dialogflow/cx/v3#WebhookResponse
type webhookResponse struct {
	FulfillmentResponse fulfillmentResponse `json:"fulfillmentResponse"`
	SessionInfo         sessionInfo         `json:"sessionInfo"`
}

// detectCustomerAnomaly handles same-named tag.
func detectCustomerAnomaly(ctx context.Context, request webhookRequest) (
	webhookResponse, error) {
	// Create session parameters that are populated in the response.
	// This example hard codes values, but a real system
	// might look up this value in a database.
	p := map[string]interface{}{
		"anomaly_detect":        "false",
		"purchase":              "device protection",
		"purchase_amount":       "12.25",
		"bill_without_purchase": "54.34",
		"total_bill":            "66.59",
		"first_month":           "January 1",
	}
	// Build and return the response.
	response := webhookResponse{
		SessionInfo: sessionInfo{
			Parameters: p,
		},
	}
	return response, nil
}

// validatePhoneLine handles same-named tag.
func validatePhoneLine(ctx context.Context, request webhookRequest) (
	webhookResponse, error) {
	// Create session parameters that are populated in the response.
	// This example hard codes values, but a real system
	// might look up this value in a database.
	p := map[string]interface{}{
		"domestic_coverage":   "true",
		"phone_line_verified": "true",
	}
	// Build and return the response.
	response := webhookResponse{
		SessionInfo: sessionInfo{
			Parameters: p,
		},
	}
	return response, nil
}

// cruisePlanCoverage handles same-named tag.
func cruisePlanCoverage(ctx context.Context, request webhookRequest) (
	webhookResponse, error) {
	// Get the existing parameter values
	port := request.SessionInfo.Parameters["destination"].(string)
	port = strings.ToLower(port)
	// Check if the port is covered
	covered := "false"
	if client != nil {
		// A Spanner client exists, so access the database.
		// See: https://pkg.go.dev/cloud.google.com/go/spanner#ReadOnlyTransaction.ReadRow
		row, err := client.Single().ReadRow(ctx,
			"Destinations",
			spanner.Key{port},
			[]string{"Covered"})
		if err != nil {
			if spanner.ErrCode(err) == codes.NotFound {
				log.Printf("Port %s not found", port)
			} else {
				return webhookResponse{}, err
			}
		} else {
			// A row was returned, so check the value
			var c bool
			err := row.Column(0, &c)
			if err != nil {
				return webhookResponse{}, err
			}
			if c {
				covered = "true"
			}
		}
	} else {
		// No Spanner client exists, so use hardcoded list of ports.
		coveredPorts := map[string]bool{
			"anguilla": true,
			"canada":   true,
			"mexico":   true,
		}
		_, ok := coveredPorts[port]
		if ok {
			covered = "true"
		}
	}
	// Create session parameters that are populated in the response.
	// This example hard codes values, but a real system
	// might look up this value in a database.
	p := map[string]interface{}{
		"port_is_covered": covered,
	}
	// Build and return the response.
	response := webhookResponse{
		SessionInfo: sessionInfo{
			Parameters: p,
		},
	}
	return response, nil
}

// internationalCoverage handles same-named tag.
func internationalCoverage(ctx context.Context, request webhookRequest) (
	webhookResponse, error) {
	// Get the existing parameter values
	destination := request.SessionInfo.Parameters["destination"].(string)
	destination = strings.ToLower(destination)
	// Hardcoded list of covered international monthly destinations
	coveredMonthly := map[string]bool{
		"anguilla":  true,
		"australia": true,
		"brazil":    true,
		"canada":    true,
		"chile":     true,
		"england":   true,
		"france":    true,
		"india":     true,
		"japan":     true,
		"mexico":    true,
		"singapore": true,
	}
	// Hardcoded list of covered international daily destinations
	coveredDaily := map[string]bool{
		"brazil":    true,
		"canada":    true,
		"chile":     true,
		"england":   true,
		"france":    true,
		"india":     true,
		"japan":     true,
		"mexico":    true,
		"singapore": true,
	}
	// Check coverage
	coverage := "neither"
	_, monthly := coveredMonthly[destination]
	_, daily := coveredDaily[destination]
	if monthly && daily {
		coverage = "both"
	} else if monthly {
		coverage = "monthly_only"
	} else if daily {
		coverage = "daily_only"
	}
	// Create session parameters that are populated in the response.
	// This example hard codes values, but a real system
	// might look up this value in a database.
	p := map[string]interface{}{
		"coverage": coverage,
	}
	// Build and return the response.
	response := webhookResponse{
		SessionInfo: sessionInfo{
			Parameters: p,
		},
	}
	return response, nil
}

// cheapestPlan handles same-named tag.
func cheapestPlan(ctx context.Context, request webhookRequest) (
	webhookResponse, error) {
	// Create session parameters that are populated in the response.
	// This example hard codes values, but a real system
	// might look up this value in a database.
	p := map[string]interface{}{
		"monthly_cost":   70,
		"daily_cost":     100,
		"suggested_plan": "monthly",
	}
	// Build and return the response.
	response := webhookResponse{
		SessionInfo: sessionInfo{
			Parameters: p,
		},
	}
	return response, nil
}

// Define a type for handler functions.
type handlerFn func(ctx context.Context, request webhookRequest) (
	webhookResponse, error)

// Create a map from tag to handler function.
var handlers map[string]handlerFn = map[string]handlerFn{
	"detectCustomerAnomaly": detectCustomerAnomaly,
	"validatePhoneLine":     validatePhoneLine,
	"cruisePlanCoverage":    cruisePlanCoverage,
	"internationalCoverage": internationalCoverage,
	"cheapestPlan":          cheapestPlan,
}

// handleError handles internal errors.
func handleError(w http.ResponseWriter, err error) {
	log.Printf("ERROR: %v", err)
	http.Error(w,
		fmt.Sprintf("ERROR: %v", err),
		http.StatusInternalServerError)
}

// HandleWebhookRequest handles WebhookRequest and sends the WebhookResponse.
func HandleWebhookRequest(w http.ResponseWriter, r *http.Request) {
	var request webhookRequest
	var response webhookResponse
	var err error

	// Read input JSON
	if err = json.NewDecoder(r.Body).Decode(&request); err != nil {
		handleError(w, err)
		return
	}
	log.Printf("Request: %+v", request)

	// Get the tag from the request, and call the corresponding
	// function that handles that tag.
	tag := request.FulfillmentInfo.Tag
	if fn, ok := handlers[tag]; ok {
		response, err = fn(r.Context(), request)
	} else {
		err = fmt.Errorf("Unknown tag: %s", tag)
	}
	if err != nil {
		handleError(w, err)
		return
	}
	log.Printf("Response: %+v", response)

	// Send response
	if err = json.NewEncoder(w).Encode(&response); err != nil {
		handleError(w, err)
		return
	}
}

Click Deploy.
Wait until the status indicator shows that the function has successfully deployed. While waiting, examine the code you just deployed.

Configure the webhook for your agent

Now that the webhook exists as a service, you will associate this webhook with your agent. To configure the webhook for your agent:

Open the Dialogflow CX console.
Choose your Google Cloud project.
Select your agent.
Select the Manage tab.
Click Webhooks.
Click the existing webhook (created by the prebuilt agent).
Update the Webhook URL to the webhook URL you saved when creating the function.
Set the Subtype to Standard.
Click Save.

Try the agent

Your agent is now ready to try. Click the Test Agent button to open the simulator. Attempt to have the following conversation with the agent:

Conversational turn	You	Agent
1	Hello	Hi! I'm the virtual telecommunications agent. I can help you resolve billing and plan questions, troubleshoot, and add travel and cruise plans. How can I assist you today?
2	I want to add a cruise plan	Let me take a look for you. What is your phone number with us?
3	123-123-1234	How many days is your cruise?
4	7	Option 1 includes talk and text. It costs $[XX]/day. More info here [URL]. Option 2 includes talk, text and data. It costs $[XX]/day. More info here [URL]. Which cruise plan would you like to add?
5	Option 1	Got it. I've added that plan to your account. While on your cruise, you may also need coverage on land. What port will you be stopping at?
6	Mexico	And, how many days are you spending there?
7	3	Great news! Mexico has free coverage on land. You're all set. Is there anything else I can help you with today?

This particular conversation was managed by the Cruise Plan flow.

At conversational turn #6, you provided "Mexico" as your destination port. The destination port and the number of days there are captured as the destination and trip_duration form parameters of the Collect Port page. Browse your agent to find these parameter definitions.

Screenshot of Collect Port page in Dialogflow counsole

In the Collect Port page, there is a condition route for form completion: $page.params.status = "FINAL". Once the two form parameters have been provided, this route is called. This route calls your webhook and provides the cruisePlanCoverage tag to your webhook. If you examine the webhook code above, you see that this tag triggers the same named function to be called.

This function determines whether the provided destination is covered by the plan. The function checks whether specific environment variables are set with information for connecting to the database. If these environment variables are not set, the function uses a hardcoded list of destinations. In upcoming steps, you will alter the environment for the function so that it retrieves data from a database in order to validate plan coverage for destinations.

Troubleshooting

The webhook code includes logging statements. If you are having issues, try viewing the logs for your function.

More information

For more information about the steps above, see:

Cloud Run functions Go quickstart

Create a prebuilt agent

Query a database