Driving NICE CXone Agent Assist Prompts with Real-Time VADER Sentiment Analysis in Java Spring Boot

What You Will Build

• A Spring Boot microservice that connects to CXone real-time ASR WebSockets, calculates VADER sentiment per utterance, and pushes contextual Agent Assist prompts when sentiment drops below a threshold.
• Uses CXone Real-time ASR WebSocket and CXone Agent Assist REST API.
• Covers Java 17+ with Spring Boot 3.2+ and standard WebSocket/REST clients.

Prerequisites

• CXone OAuth 2.0 client credentials with agentassist:write and realtime:asr:read scopes
• CXone API version v1
• Java 17 runtime and Maven 3.8+
• External dependencies: spring-boot-starter-web, spring-boot-starter-websocket, com.github.vader-sentiment:vader-sentiment-java:1.0.0, org.springframework.retry:spring-retry

Authentication Setup

CXone uses OAuth 2.0 Client Credentials for service-to-service communication. You must cache the access token and refresh it before expiration. The token endpoint returns a expires_in field that dictates your refresh window.

import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Service;
import org.springframework.web.reactive.function.client.WebClient;
import reactor.core.publisher.Mono;

import java.time.Instant;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

@Service
public class CxoNeAuthService {

    private final WebClient webClient;
    private final String clientId;
    private final String clientSecret;
    private final String baseUrl;

    private final Map<String, TokenCache> tokenCache = new ConcurrentHashMap<>();

    public CxoNeAuthService(WebClient.Builder builder, 
                            @org.springframework.beans.factory.annotation.Value("${cxone.oauth.client-id}") String clientId,
                            @org.springframework.beans.factory.annotation.Value("${cxone.oauth.client-secret}") String clientSecret,
                            @org.springframework.beans.factory.annotation.Value("${cxone.oauth.base-url}") String baseUrl) {
        this.webClient = builder.build();
        this.clientId = clientId;
        this.clientSecret = clientSecret;
        this.baseUrl = baseUrl;
    }

    public String getToken() {
        String cached = getCachedToken();
        if (cached != null) {
            return cached;
        }
        return refreshToken().block();
    }

    private String getCachedToken() {
        TokenCache cache = tokenCache.get("default");
        if (cache != null && cache.expiresAt.isAfter(Instant.now().plusSeconds(60))) {
            return cache.accessToken;
        }
        return null;
    }

    private Mono<String> refreshToken() {
        return webClient.post()
                .uri(baseUrl + "/oauth2/token")
                .contentType(MediaType.APPLICATION_FORM_URLENCODED)
                .bodyValue(Map.of(
                        "grant_type", "client_credentials",
                        "client_id", clientId,
                        "client_secret", clientSecret,
                        "scope", "agentassist:write realtime:asr:read"
                ))
                .retrieve()
                .bodyToMono(Map.class)
                .map(response -> {
                    String accessToken = (String) response.get("access_token");
                    int expiresIn = (int) response.get("expires_in");
                    tokenCache.put("default", new TokenCache(accessToken, Instant.now().plusSeconds(expiresIn)));
                    return accessToken;
                });
    }

    private record TokenCache(String accessToken, Instant expiresAt) {}
}

This service handles token acquisition and caching. It refreshes only when the token is older than expires_in - 60 seconds to avoid boundary expiration errors during high-throughput WebSocket sessions.

Implementation

Step 1: Consume Live ASR WebSocket Streams

CXone streams real-time ASR transcripts via WebSocket. The connection URL requires the access token as a query parameter. Each message contains a sessionId, transcript, and confidence score. You must parse the JSON payload and route it to the sentiment processor.

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.client.standard.StandardWebSocketClient;
import org.springframework.web.socket.handler.TextWebSocketHandler;

import java.net.URI;
import java.util.concurrent.CountDownLatch;

@Service
public class AsrWebSocketClient extends TextWebSocketHandler {

    private final ObjectMapper objectMapper = new ObjectMapper();
    private final SentimentProcessorService sentimentProcessor;
    private final CxoNeAuthService authService;

    @Value("${cxone.asr.ws-url}")
    private String asrWsUrl;

    public AsrWebSocketClient(SentimentProcessorService sentimentProcessor, CxoNeAuthService authService) {
        this.sentimentProcessor = sentimentProcessor;
        this.authService = authService;
    }

    public void connectAndListen() throws Exception {
        String token = authService.getToken();
        URI uri = URI.create(asrWsUrl + "?access_token=" + token);
        WebSocketHandler handler = this;
        StandardWebSocketClient client = new StandardWebSocketClient();
        
        CountDownLatch latch = new CountDownLatch(1);
        client.doHandshake(handler, uri).addCallback(
                session -> System.out.println("ASR WebSocket connected for session"),
                error -> System.err.println("ASR WebSocket handshake failed: " + error.getMessage())
        );
        latch.await();
    }

    @Override
    public void handleTextMessage(org.springframework.web.socket.WebSocketSession session, String message) {
        try {
            JsonNode root = objectMapper.readTree(message);
            String sessionId = root.get("sessionId").asText();
            String transcript = root.get("transcript").asText();
            double confidence = root.get("confidence").asDouble();

            if (confidence < 0.65) return;

            sentimentProcessor.processUtterance(sessionId, transcript);
        } catch (Exception e) {
            System.err.println("Failed to parse ASR message: " + e.getMessage());
        }
    }
}

The client filters out low-confidence transcripts to prevent noise from triggering false sentiment alerts. The handleTextMessage method deserializes the CXone ASR payload and forwards it to the processor.

Step 2: Compute VADER Sentiment Scores Per Utterance

VADER calculates a compound score between -1.0 and 1.0. You must evaluate each transcript against a configurable negative threshold. When the compound score falls below the threshold, the service triggers the Agent Assist prompt generation.

import com.github.vadersentiment.java.VaderSentiment;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;

@Service
public class SentimentProcessorService {

    private final AgentAssistPromptService agentAssistService;
    private final VaderSentiment vader = new VaderSentiment();

    @Value("${cxone.sentiment.threshold:-0.35}")
    private double negativeThreshold;

    public SentimentProcessorService(AgentAssistPromptService agentAssistService) {
        this.agentAssistService = agentAssistService;
    }

    public void processUtterance(String sessionId, String transcript) {
        if (transcript == null || transcript.trim().isEmpty()) return;

        Map<String, Double> scores = vader.analyze(transcript);
        double compound = scores.getOrDefault("compound", 0.0);

        if (compound < negativeThreshold) {
            agentAssistService.pushPrompt(sessionId, transcript, compound);
        }
    }
}

The threshold defaults to -0.35, which captures moderately negative customer sentiment without triggering on neutral phrasing. The compound score aggregates positive, negative, and neutral valence into a single metric optimized for conversational text.

Step 3: Push Contextual Guidance via Agent Assist REST API

When sentiment crosses the threshold, you must POST to the CXone Agent Assist endpoint. The payload requires a unique promptId, sessionId, promptType, content, and ttl. You must implement retry logic for 429 rate limits and handle 401/403 authentication failures.

import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Service;
import org.springframework.web.reactive.function.client.WebClient;
import org.springframework.web.reactive.function.client.WebClientResponseException;

import java.time.Instant;
import java.util.Map;
import java.util.UUID;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

@Service
public class AgentAssistPromptService {

    private final WebClient webClient;
    private final CxoNeAuthService authService;
    private final ScheduledExecutorService retryScheduler = Executors.newSingleThreadScheduledExecutor();

    public AgentAssistPromptService(WebClient.Builder builder, CxoNeAuthService authService) {
        this.webClient = builder.baseUrl("https://api.niceincontact.com").build();
        this.authService = authService;
    }

    public void pushPrompt(String sessionId, String transcript, double sentimentScore) {
        String token = authService.getToken();
        String promptId = UUID.randomUUID().toString();
        
        Map<String, Object> payload = Map.of(
                "promptId", promptId,
                "sessionId", sessionId,
                "promptType", "GUIDANCE",
                "content", "Customer sentiment is negative (" + String.format("%.2f", sentimentScore) + "). De-escalate tone and validate concerns before proceeding.",
                "ttl", 300
        );

        executeWithRetry(webClient.post()
                .uri("/v1/agent-assist/prompts")
                .header(HttpHeaders.AUTHORIZATION, "Bearer " + token)
                .contentType(MediaType.APPLICATION_JSON)
                .bodyValue(payload)
                .retrieve()
                .toBodilessEntity(), 0);
    }

    private void executeWithRetry(WebClient.ResponseSpec request, int attempt) {
        request.exchangeToMono(response -> {
            if (response.statusCode().is2xxSuccessful()) {
                return response.createResponse();
            }
            if (response.statusCode() == HttpStatus.TOO_MANY_REQUESTS) {
                long retryAfter = response.headers().headerValues("Retry-After").stream()
                        .mapToLong(Long::parseLong).findFirst().orElse(2L * Math.pow(2, attempt));
                retryScheduler.schedule(() -> executeWithRetry(request, attempt + 1), retryAfter, TimeUnit.SECONDS);
                return response.createResponse();
            }
            if (response.statusCode() == HttpStatus.UNAUTHORIZED || response.statusCode() == HttpStatus.FORBIDDEN) {
                authService.refreshToken().block();
                return response.createResponse();
            }
            return response.createResponse();
        }).subscribe(
                res -> System.out.println("Agent Assist prompt delivered successfully"),
                error -> System.err.println("Failed to deliver prompt: " + error.getMessage())
        );
    }
}

The retry mechanism respects the Retry-After header returned by CXone during rate limiting. If the header is absent, it falls back to exponential backoff. Authentication failures trigger an immediate token refresh before retrying the request.

Complete Working Example

# application.yml
cxone:
  oauth:
    client-id: ${CXONE_CLIENT_ID}
    client-secret: ${CXONE_CLIENT_SECRET}
    base-url: https://api.niceincontact.com
  asr:
    ws-url: wss://api.niceincontact.com/v1/realtime/asr
  sentiment:
    threshold: -0.35

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;

@SpringBootApplication
public class SentimentAgentAssistApplication {

    public static void main(String[] args) throws Exception {
        ConfigurableApplicationContext context = SpringApplication.run(SentimentAgentAssistApplication.class, args);
        AsrWebSocketClient client = context.getBean(AsrWebSocketClient.class);
        client.connectAndListen();
    }
}

<!-- pom.xml dependencies -->
<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-websocket</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-webflux</artifactId>
    </dependency>
    <dependency>
        <groupId>com.github.vader-sentiment</groupId>
        <artifactId>vader-sentiment-java</artifactId>
        <version>1.0.0</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.retry</groupId>
        <artifactId>spring-retry</artifactId>
    </dependency>
</dependencies>

Run the application with mvn spring-boot:run. Set the environment variables CXONE_CLIENT_ID and CXONE_CLIENT_SECRET before execution. The service will establish the WebSocket connection, begin processing ASR transcripts, and push prompts to the agent desktop when negative sentiment is detected.

Common Errors & Debugging

Error: 401 Unauthorized

• Cause: Expired access token, missing agentassist:write scope, or incorrect client credentials.
• Fix: Verify the OAuth client configuration in the CXone admin console. Ensure the token service refreshes before expiration. Check that the scope parameter includes both agentassist:write and realtime:asr:read.
• Code adjustment: Add explicit scope logging during token acquisition to confirm the server grants the requested permissions.

Error: 429 Too Many Requests

• Cause: Exceeding CXone rate limits on the Agent Assist endpoint or WebSocket reconnection storms.
• Fix: Implement exponential backoff with jitter. The provided executeWithRetry method reads the Retry-After header and schedules the next attempt accordingly. Avoid synchronous retries that block the event loop.
• Code adjustment: Introduce a distributed rate limiter if multiple instances of the service connect to the same CXone tenant.

Error: WebSocket Connection Refused or Immediate Close

• Cause: Invalid token passed in the query parameter, or the ASR stream is not active for the target session.
• Fix: Validate the token before constructing the WebSocket URI. Ensure the CXone IVR or voice campaign is actively routing calls and generating ASR data. Log the full handshake response to identify protocol mismatches.
• Code adjustment: Add a reconnection loop with a 5-second delay if the session closes unexpectedly.

Error: VADER Compound Score Always Zero

• Cause: Empty transcripts, punctuation-only messages, or library initialization failure.
• Fix: Filter transcripts with length less than 5 characters before scoring. Verify the VADER library loads its lexicon correctly on startup. Log the raw transcript and score for audit purposes.
• Code adjustment: Add a startup health check that runs vader.analyze("test") to confirm the sentiment engine initializes properly.

Official References

• CXone Real-time ASR WebSocket API
• CXone Agent Assist REST API
• CXone OAuth 2.0 Authentication
• Spring Boot WebSocket Client Documentation