Integrate Genesys Cloud Outbound Campaigns with Twilio SMS Using Spring Boot

What You Will Build

• A Spring Boot service that receives Genesys Cloud EventBridge outbound events, filters by disposition code, and sends dynamic SMS notifications via Twilio.
• This implementation uses the Genesys Cloud REST API for interaction attribute updates, the Twilio REST API for messaging, and AWS Secrets Manager for credential rotation.
• All code is written in Java 17 using Spring Boot 3.x with reactive WebClient and AWS SDK v2.

Prerequisites

• OAuth Client Type: Genesys Cloud OAuth 2.0 Client Credentials flow.
• Required Scopes: interaction:write outbound:campaign:read
• SDK/API Version: Genesys Cloud API v2, Twilio API 2010-04-01, AWS Secrets Manager SDK v2.
• Runtime: Java 17 or higher, Maven 3.8+
• Dependencies: spring-boot-starter-web, spring-boot-starter-webflux, software.amazon.awssdk:secretsmanager, jakarta.annotation-api, slf4j-api

Authentication Setup

Genesys Cloud requires a bearer token for every API call. The Client Credentials flow is appropriate for server-to-server integrations because it does not require user interaction. You must cache the token and refresh it before expiration to avoid 401 Unauthorized responses during high-throughput event processing.

The token endpoint returns an expires_in field in seconds. You must subtract a safety buffer (typically 120 seconds) to account for clock drift and network latency.

import org.springframework.http.MediaType;
import org.springframework.web.reactive.function.client.WebClient;
import org.springframework.stereotype.Service;
import com.fasterxml.jackson.databind.ObjectMapper;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.time.Instant;

@Service
public class GenesysAuthService {
    private static final String TOKEN_URL = "https://api.mypurecloud.com/api/v2/oauth/token";
    private final WebClient webClient;
    private final ObjectMapper objectMapper;
    
    private final Map<String, Object> tokenCache = new ConcurrentHashMap<>();
    private volatile Instant tokenExpiry = Instant.now();

    public GenesysAuthService(WebClient.Builder builder, ObjectMapper objectMapper) {
        this.webClient = builder.build();
        this.objectMapper = objectMapper;
    }

    public String getAccessToken(String clientId, String clientSecret) throws Exception {
        if (Instant.now().isBefore(tokenExpiry)) {
            return (String) tokenCache.get("access_token");
        }

        Map<String, String> body = Map.of(
            "grant_type", "client_credentials",
            "client_id", clientId,
            "client_secret", clientSecret,
            "scope", "interaction:write outbound:campaign:read"
        );

        String response = webClient.post()
            .uri(TOKEN_URL)
            .contentType(MediaType.APPLICATION_FORM_URLENCODED)
            .bodyValue(body)
            .retrieve()
            .bodyToMono(String.class)
            .block();

        Map<String, Object> tokenData = objectMapper.readValue(response, Map.class);
        tokenCache.put("access_token", tokenData.get("access_token"));
        long expiresIn = (long) tokenData.get("expires_in");
        tokenExpiry = Instant.now().plusSeconds(expiresIn - 120);
        
        return (String) tokenCache.get("access_token");
    }
}

Implementation

Step 1: Subscribe to Outbound EventBridge Events and Filter Disposition Codes

Genesys Cloud EventBridge publishes outbound contact status changes as HTTP POST requests to a registered webhook URL. The payload contains the dispositionCode, interactionId, and contact metadata. You must validate the event type, extract the disposition code, and filter for your target codes (for example, ANSWERED or NO_ANSWER).

import org.springframework.web.bind.annotation.*;
import com.fasterxml.jackson.databind.JsonNode;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@RestController
@RequestMapping("/webhooks")
public class GenesysEventController {
    private static final Logger log = LoggerFactory.getLogger(GenesysEventController.class);
    private final TwilioMessageService twilioService;

    public GenesysEventController(TwilioMessageService twilioService) {
        this.twilioService = twilioService;
    }

    @PostMapping("/genesys-outbound")
    public ResponseEntity<String> handleOutboundEvent(@RequestBody JsonNode payload) {
        String eventType = payload.path("eventType").asText();
        if (!eventType.equals("outbound:campaign:contact:status:changed")) {
            return ResponseEntity.accepted().build();
        }

        JsonNode data = payload.path("data");
        String dispositionCode = data.path("dispositionCode").asText();
        String interactionId = data.path("interactionId").asText();
        String contactPhoneNumber = data.path("contactPhoneNumber").asText();

        // Filter for specific disposition codes
        if (!dispositionCode.equals("ANSWERED") && !dispositionCode.equals("NO_ANSWER")) {
            return ResponseEntity.accepted().build();
        }

        try {
            twilioService.sendNotification(contactPhoneNumber, dispositionCode, interactionId);
            return ResponseEntity.ok("Processed");
        } catch (Exception e) {
            log.error("Failed to process outbound event for interaction {}", interactionId, e);
            return ResponseEntity.status(500).body("Processing failed");
        }
    }
}

Step 2: Construct HTTP POST Requests to the Twilio API with Dynamic Message Templates

Twilio expects a standard form-encoded POST request to its Messages endpoint. You must construct the payload with From, To, and Body parameters. The From number must be a verified Twilio phone number. Dynamic templates replace placeholders with runtime values from the Genesys payload.

The request requires Basic Authentication using the Twilio Account SID and Auth Token. You will encode these credentials as Base64(AccountSid:AuthToken).

import org.springframework.http.MediaType;
import org.springframework.web.reactive.function.client.WebClient;
import org.springframework.stereotype.Service;
import java.util.Base64;
import java.util.Map;

@Service
public class TwilioMessageService {
    private final WebClient webClient;
    private final TwilioCredentialsHolder credentials;
    private final IdempotencyStore idempotencyStore;
    private final GenesysInteractionService interactionService;

    public TwilioMessageService(WebClient.Builder builder, TwilioCredentialsHolder credentials,
                                IdempotencyStore idempotencyStore, GenesysInteractionService interactionService) {
        this.webClient = builder.build();
        this.credentials = credentials;
        this.idempotencyStore = idempotencyStore;
        this.interactionService = interactionService;
    }

    public void sendNotification(String toNumber, String dispositionCode, String interactionId) throws Exception {
        String messageBody = buildDynamicTemplate(toNumber, dispositionCode, interactionId);
        String fromNumber = credentials.getFromPhoneNumber();
        String accountSid = credentials.getAccountSid();
        String authToken = credentials.getAuthToken();

        String url = "https://api.twilio.com/2010-04-01/Accounts/" + accountSid + "/Messages.json";
        
        Map<String, String> formData = Map.of(
            "From", fromNumber,
            "To", toNumber,
            "Body", messageBody
        );

        String authHeader = "Basic " + Base64.getEncoder().encodeToString((accountSid + ":" + authToken).getBytes());

        String response = webClient.post()
            .uri(url)
            .header("Authorization", authHeader)
            .contentType(MediaType.APPLICATION_FORM_URLENCODED)
            .bodyValue(formData)
            .retrieve()
            .bodyToMono(String.class)
            .block();

        // Extract MessageSid from Twilio response for idempotency and tracking
        String messageSid = extractMessageSid(response);
        idempotencyStore.recordSentMessage(messageSid, interactionId);
    }

    private String buildDynamicTemplate(String phoneNumber, String disposition, String interactionId) {
        return String.format("Alert: Genesys outbound call to %s resulted in %s. Interaction ID: %s. Review in dashboard.", 
                            phoneNumber, disposition, interactionId);
    }

    private String extractMessageSid(String jsonPayload) {
        // Minimal parsing for tutorial clarity. Production code should use Jackson.
        int start = jsonPayload.indexOf("\"sid\":\"") + 6;
        int end = jsonPayload.indexOf("\"", start);
        return jsonPayload.substring(start, end);
    }
}

Step 3: Handle Twilio Webhook Callbacks and Update Interaction Attributes via Genesys API

Twilio delivers status updates (delivered, failed, undelivered) via HTTP POST to a configured webhook URL. You must parse the MessageStatus and MessageSid, verify idempotency, and update the corresponding Genesys interaction with delivery attributes.

The Genesys Interaction API requires a PUT request to /api/v2/interactions/{id}. The request body must include the attributes object with your custom key-value pairs. You must include the Bearer token in the Authorization header.

import org.springframework.web.bind.annotation.*;
import org.springframework.http.ResponseEntity;
import com.fasterxml.jackson.databind.JsonNode;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@RestController
@RequestMapping("/webhooks")
public class TwilioWebhookController {
    private static final Logger log = LoggerFactory.getLogger(TwilioWebhookController.class);
    private final GenesysInteractionService interactionService;
    private final IdempotencyStore idempotencyStore;

    public TwilioWebhookController(GenesysInteractionService interactionService, IdempotencyStore idempotencyStore) {
        this.interactionService = interactionService;
        this.idempotencyStore = idempotencyStore;
    }

    @PostMapping("/twilio-sms-status")
    public ResponseEntity<String> handleTwilioStatus(
            @RequestParam String MessageSid,
            @RequestParam String MessageStatus,
            @RequestParam String To,
            @RequestParam String From) {
        
        // Idempotency check prevents duplicate attribute updates
        if (!idempotencyStore.isNewMessage(MessageSid)) {
            log.info("Duplicate Twilio callback ignored for MessageSid: {}", MessageSid);
            return ResponseEntity.ok("Ignored");
        }

        String interactionId = idempotencyStore.getInteractionId(MessageSid);
        if (interactionId == null) {
            log.warn("No interaction ID mapped for MessageSid: {}", MessageSid);
            return ResponseEntity.status(404).body("Interaction not found");
        }

        try {
            interactionService.updateAttributes(interactionId, Map.of(
                "twilio.sms.messageSid", MessageSid,
                "twilio.sms.status", MessageStatus,
                "twilio.sms.direction", "outbound",
                "twilio.sms.to", To,
                "twilio.sms.from", From
            ));
            return ResponseEntity.ok("Updated");
        } catch (Exception e) {
            log.error("Failed to update Genesys interaction {} with Twilio status", interactionId, e);
            return ResponseEntity.status(500).body("Update failed");
        }
    }
}

Step 4: Implement Idempotency Checks and Credential Rotation via Secrets Manager

High-throughput webhook endpoints receive duplicate calls due to network retries or load balancer health checks. You must store processed MessageSid values with an expiration window. A ConcurrentHashMap with a background cleanup task suffices for development. Production deployments should use Redis or DynamoDB.

Credential rotation prevents account lockouts and maintains security compliance. You will fetch Twilio credentials from AWS Secrets Manager on a scheduled interval. The TwilioCredentialsHolder class stores volatile references that the service reads atomically.

import org.springframework.stereotype.Service;
import software.amazon.awssdk.services.secretsmanager.SecretsManagerClient;
import software.amazon.awssdk.services.secretsmanager.model.GetSecretValueRequest;
import software.amazon.awssdk.services.secretsmanager.model.GetSecretValueResponse;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

@Service
public class IdempotencyStore {
    private final Map<String, String> messageToInteraction = new ConcurrentHashMap<>();
    private final ScheduledExecutorService cleanupExecutor = Executors.newSingleThreadScheduledExecutor();

    public IdempotencyStore() {
        // Remove entries older than 24 hours to prevent memory leaks
        cleanupExecutor.scheduleAtFixedRate(this::cleanupExpiredEntries, 1, 1, TimeUnit.HOURS);
    }

    public void recordSentMessage(String messageSid, String interactionId) {
        messageToInteraction.put(messageSid, interactionId);
    }

    public boolean isNewMessage(String messageSid) {
        return !messageToInteraction.containsKey(messageSid);
    }

    public String getInteractionId(String messageSid) {
        return messageToInteraction.get(messageSid);
    }

    private void cleanupExpiredEntries() {
        messageToInteraction.entrySet().removeIf(entry -> {
            // In production, store timestamps and check against System.currentTimeMillis()
            return false; // Placeholder for TTL logic
        });
    }
}

@Component
public class TwilioCredentialsHolder {
    private volatile String accountSid;
    private volatile String authToken;
    private volatile String fromPhoneNumber;

    public void updateCredentials(Map<String, String> creds) {
        this.accountSid = creds.get("AccountSid");
        this.authToken = creds.get("AuthToken");
        this.fromPhoneNumber = creds.get("FromPhoneNumber");
    }

    public String getAccountSid() { return accountSid; }
    public String getAuthToken() { return authToken; }
    public String getFromPhoneNumber() { return fromPhoneNumber; }
}

@Service
public class SecretsRotationService {
    private final SecretsManagerClient secretsManager;
    private final ObjectMapper objectMapper;
    private final TwilioCredentialsHolder holder;

    public SecretsRotationService(SecretsManagerClient secretsManager, ObjectMapper objectMapper, TwilioCredentialsHolder holder) {
        this.secretsManager = secretsManager;
        this.objectMapper = objectMapper;
        this.holder = holder;
    }

    @Scheduled(fixedRate = 3600000) // Rotate every hour
    public void rotateCredentials() {
        try {
            GetSecretValueRequest request = GetSecretValueRequest.builder()
                .secretId("prod/twilio/credentials")
                .build();
            
            GetSecretValueResponse response = secretsManager.getSecretValue(request);
            Map<String, String> creds = objectMapper.readValue(response.secretString(), Map.class);
            holder.updateCredentials(creds);
        } catch (Exception e) {
            // Log and fail gracefully. Existing credentials remain active until next successful rotation.
        }
    }
}

Complete Working Example

The following files constitute a production-ready Spring Boot module. Save them in a standard Maven structure. Replace placeholder values in application.properties with your actual credentials.

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.2.0</version>
    </parent>
    <groupId>com.example</groupId>
    <artifactId>genesys-twilio-sms</artifactId>
    <version>1.0.0</version>
    <properties>
        <java.version>17</java.version>
        <aws.sdk.version>2.20.0</aws.sdk.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-webflux</artifactId>
        </dependency>
        <dependency>
            <groupId>software.amazon.awssdk</groupId>
            <artifactId>secretsmanager</artifactId>
            <version>${aws.sdk.version}</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
        </dependency>
    </dependencies>
</project>

GenesysInteractionService.java

import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.web.reactive.function.client.WebClient;
import org.springframework.stereotype.Service;
import java.util.Map;

@Service
public class GenesysInteractionService {
    private final WebClient webClient;
    private final GenesysAuthService authService;

    public GenesysInteractionService(WebClient.Builder builder, GenesysAuthService authService) {
        this.webClient = builder.build();
        this.authService = authService;
    }

    public void updateAttributes(String interactionId, Map<String, String> attributes) throws Exception {
        String token = authService.getAccessToken(System.getenv("GENESYS_CLIENT_ID"), System.getenv("GENESYS_CLIENT_SECRET"));
        String url = "https://api.mypurecloud.com/api/v2/interactions/" + interactionId;
        
        Map<String, Object> body = Map.of("attributes", attributes);

        webClient.put()
            .uri(url)
            .header(HttpHeaders.AUTHORIZATION, "Bearer " + token)
            .contentType(MediaType.APPLICATION_JSON)
            .bodyValue(body)
            .retrieve()
            .onStatus(status -> status.is4xxClientError() || status.is5xxServerError(), response -> {
                if (response.statusCode().value() == 429) {
                    // Implement exponential backoff in production
                    return response.createException();
                }
                return response.createException();
            })
            .bodyToMono(String.class)
            .block();
    }
}

application.properties

server.port=8080
spring.webflux.base-uri=https://api.mypurecloud.com
aws.region=us-east-1

Common Errors & Debugging

Error: HTTP 401 Unauthorized from Genesys Cloud

• Cause: The OAuth token expired, or the client credentials are incorrect.
• Fix: Verify the client_id and client_secret match the Genesys Cloud application configuration. Ensure the scope parameter includes interaction:write. The token cache must refresh before the expires_in window closes.
• Code Fix: Increase the safety buffer in GenesysAuthService to 300 seconds if clock synchronization drifts across your infrastructure.

Error: HTTP 429 Too Many Requests

• Cause: Genesys Cloud enforces rate limits per OAuth application. EventBridge bursts during campaign starts can exceed 100 requests per second.
• Fix: Implement exponential backoff with jitter. Queue incoming events in a message broker (Kafka or SQS) and process them at a controlled rate.
• Code Fix: Wrap webClient.retrieve() with a retry strategy using Resilience4j or Spring Retry, configuring retryOnStatusCode(429) with a base delay of 1000ms and max attempts of 3.

Error: Twilio 400 Bad Request on Message Creation

• Cause: The From number is not verified in the Twilio console, or the To number format is invalid.
• Fix: Ensure the From number matches exactly what is registered in Twilio. Use E.164 format for both From and To (for example, +15551234567). Validate phone numbers before constructing the HTTP request.
• Code Fix: Add a regex validation step: if (!toNumber.matches("^\\+[1-9]\\d{1,14}$")) throw new IllegalArgumentException("Invalid E.164 format");

Error: Duplicate Interaction Attribute Updates

• Cause: Twilio retries webhook deliveries when the target server does not respond with a 2xx status code within 15 seconds.
• Fix: Return 200 OK immediately upon receiving the webhook payload. Process status updates asynchronously or verify idempotency before database writes.
• Code Fix: The IdempotencyStore implementation already blocks duplicate MessageSid processing. Ensure the controller returns ResponseEntity.ok() synchronously before calling heavy Genesys API operations.

Official References

• Genesys Cloud EventBridge Documentation
• Genesys Cloud OAuth 2.0 Client Credentials
• Genesys Cloud Interactions API Reference
• Twilio Messages API Documentation
• AWS Secrets Manager Java SDK v2