Delivering NICE CXone Agent Assist Real-Time Prompts via Agent Assist APIs with Go

What You Will Build

You will build a Go service that constructs, validates, and delivers real-time Agent Assist prompts to CXone agents via REST and WebSocket, tracks delivery metrics, and exposes a reusable prompt deliverer. The code uses the CXone Agent Assist REST endpoint and WebSocket stream with raw HTTP and gorilla/websocket. The implementation covers Go 1.21+.

Prerequisites

• OAuth 2.0 client credentials flow configured in CXone with scopes: agent-assist:prompt:write and agent-assist:ws:connect
• CXone organization ID and base URL (e.g., https://your-org.platform.nicecxone.com)
• Go 1.21+ runtime
• External dependencies: github.com/gorilla/websocket, golang.org/x/oauth2, log/slog, sync/atomic, encoding/json, net/http, time, fmt, errors

Authentication Setup

CXone uses OAuth 2.0 client credentials for server-to-server API access. You must cache the access token and handle expiration to avoid repeated token requests during prompt delivery iterations.

package main

import (
	"context"
	"crypto/tls"
	"encoding/json"
	"fmt"
	"log/slog"
	"net/http"
	"sync"
	"sync/atomic"
	"time"

	"github.com/gorilla/websocket"
	"golang.org/x/oauth2/clientcredentials"
)

type CXoneConfig struct {
	OrgID          string
	ClientID       string
	ClientSecret   string
	BaseURL        string
	WebhookURL     string
	RelevanceMin   float64
	AgentPrefs     map[string]bool
}

type AssistPrompt struct {
	PromptRef        string            `json:"prompt_ref"`
	ContextMatrix    map[string]string `json:"context_matrix"`
	DisplayDirective string            `json:"display_directive"`
	Content          string            `json:"content"`
	RelevanceScore   float64           `json:"relevance_score"`
	AgentID          string            `json:"agent_id"`
}

type DeliveryMetrics struct {
	TotalDeliveries int64
	SuccessCount    int64
	FailureCount    int64
	TotalLatency    int64 // nanoseconds
}

type PromptDeliverer struct {
	Config  CXoneConfig
	Metrics DeliveryMetrics
	Logger  *slog.Logger
	mu      sync.Mutex
	token   string
	expires time.Time
}

func (d *PromptDeliverer) getAccessToken() error {
	d.mu.Lock()
	defer d.mu.Unlock()

	if time.Now().Before(d.expires.Add(-30 * time.Second)) {
		return nil
	}

	conf := &clientcredentials.Config{
		ClientID:     d.Config.ClientID,
		ClientSecret: d.Config.ClientSecret,
		TokenURL:     fmt.Sprintf("%s/oauth2/token", d.Config.BaseURL),
		Scopes:       []string{"agent-assist:prompt:write", "agent-assist:ws:connect"},
	}

	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()

	token, err := conf.Token(ctx)
	if err != nil {
		return fmt.Errorf("oauth token fetch failed: %w", err)
	}

	d.token = token.AccessToken
	d.expires = token.Expiry
	return nil
}

The token fetch uses a thirty-second grace period before expiry to prevent mid-flight request failures. The getAccessToken method is guarded by a mutex to prevent concurrent token refresh races.

Implementation

Step 1: Construct and Validate Payload Against Assist Engine Constraints

The CXone assist engine enforces strict payload schemas and maximum content lengths. You must validate prompt references, context matrices, display directives, relevance scores, and agent preferences before transmission.

const maxPromptLength = 4096

func (d *PromptDeliverer) validatePrompt(p AssistPrompt) error {
	// Schema constraint: prompt_ref must be non-empty
	if p.PromptRef == "" {
		return fmt.Errorf("prompt_ref is required")
	}

	// Context matrix must contain at least conversation_id
	if _, ok := p.ContextMatrix["conversation_id"]; !ok {
		return fmt.Errorf("context_matrix missing conversation_id")
	}

	// Display directive must match allowed values
	validDirectives := map[string]bool{
		"inline": true, "sidebar": true, "modal": true, "toast": true,
	}
	if !validDirectives[p.DisplayDirective] {
		return fmt.Errorf("invalid display_directive: %s", p.DisplayDirective)
	}

	// Max prompt length limit enforcement
	if len(p.Content) > maxPromptLength {
		return fmt.Errorf("content exceeds maximum length limit of %d characters", maxPromptLength)
	}

	// Relevance scoring pipeline
	if p.RelevanceScore < d.Config.RelevanceMin {
		return fmt.Errorf("relevance score %.2f below minimum threshold %.2f", p.RelevanceScore, d.Config.RelevanceMin)
	}

	// Agent preference verification pipeline
	if !d.Config.AgentPrefs[p.AgentID] {
		return fmt.Errorf("agent %s has disabled assist prompts", p.AgentID)
	}

	return nil
}

The validation pipeline executes sequentially. The relevance scoring check prevents low-value prompts from consuming agent attention. The agent preference verification ensures compliance with agent opt-in settings. The maximum length check aligns with CXone assist engine constraints to prevent HTTP 413 responses.

Step 2: REST Delivery, Webhook Synchronization, and Metrics Tracking

You will deliver the validated payload via POST /api/v1/agent-assist/prompt. The request includes the OAuth bearer token. On success, the service synchronizes with an external knowledge base webhook, tracks latency, and records audit logs.

func (d *PromptDeliverer) deliverViaREST(p AssistPrompt) error {
	if err := d.validatePrompt(p); err != nil {
		d.Logger.Warn("prompt validation failed", "error", err, "agent_id", p.AgentID)
		atomic.AddInt64(&d.Metrics.FailureCount, 1)
		return err
	}

	if err := d.getAccessToken(); err != nil {
		return fmt.Errorf("authentication failed: %w", err)
	}

	payload, err := json.Marshal(p)
	if err != nil {
		return fmt.Errorf("json marshal failed: %w", err)
	}

	start := time.Now()
	req, err := http.NewRequestWithContext(context.Background(), http.MethodPost,
		fmt.Sprintf("%s/api/v1/agent-assist/prompt", d.Config.BaseURL),
		bytes.NewReader(payload))
	if err != nil {
		return fmt.Errorf("request creation failed: %w", err)
	}

	req.Header.Set("Authorization", "Bearer "+d.token)
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("X-NICE-Organization-ID", d.Config.OrgID)

	client := &http.Client{Timeout: 15 * time.Second}
	resp, err := client.Do(req)
	if err != nil {
		atomic.AddInt64(&d.Metrics.FailureCount, 1)
		d.Logger.Error("rest delivery request failed", "error", err, "agent_id", p.AgentID)
		return fmt.Errorf("http request failed: %w", err)
	}
	defer resp.Body.Close()

	latency := time.Since(start).Nanoseconds()
	atomic.AddInt64(&d.Metrics.TotalDeliveries, 1)
	atomic.AddInt64(&d.Metrics.TotalLatency, latency)

	if resp.StatusCode != http.StatusCreated && resp.StatusCode != http.StatusOK {
		atomic.AddInt64(&d.Metrics.FailureCount, 1)
		body := make([]byte, 1024)
		n, _ := resp.Body.Read(body)
		d.Logger.Error("rest delivery rejected", "status", resp.StatusCode, "body", string(body[:n]), "agent_id", p.AgentID)
		return fmt.Errorf("cxone rejected prompt: status %d", resp.StatusCode)
	}

	atomic.AddInt64(&d.Metrics.SuccessCount, 1)
	d.Logger.Info("prompt delivered successfully",
		"agent_id", p.AgentID,
		"prompt_ref", p.PromptRef,
		"latency_ms", latency/1e6,
		"status", resp.StatusCode)

	// Audit log for assist governance
	d.Logger.Info("assist_audit",
		"event", "prompt_delivered",
		"agent_id", p.AgentID,
		"prompt_ref", p.PromptRef,
		"directive", p.DisplayDirective,
		"relevance", p.RelevanceScore,
		"timestamp", time.Now().UTC().Format(time.RFC3339))

	// Synchronize with external knowledge base via webhook
	go d.syncWebhook(p, resp.StatusCode)

	return nil
}

func (d *PromptDeliverer) syncWebhook(p AssistPrompt, status int) {
	webhookPayload := map[string]interface{}{
		"event":      "prompt_delivered",
		"agent_id":   p.AgentID,
		"prompt_ref": p.PromptRef,
		"status":     status,
		"timestamp":  time.Now().UTC().Format(time.RFC3339),
	}

	body, _ := json.Marshal(webhookPayload)
	req, _ := http.NewRequestWithContext(context.Background(), http.MethodPost, d.Config.WebhookURL, bytes.NewReader(body))
	req.Header.Set("Content-Type", "application/json")

	client := &http.Client{Timeout: 5 * time.Second}
	resp, err := client.Do(req)
	if err != nil || resp.StatusCode >= 400 {
		d.Logger.Warn("webhook sync failed", "error", err, "status", resp.StatusCode)
		return
	}
	defer resp.Body.Close()
}

The REST delivery tracks latency in nanoseconds and updates atomic counters for thread-safe metrics aggregation. The webhook synchronization runs asynchronously to avoid blocking the main delivery thread. The audit log captures governance-required fields including agent ID, prompt reference, directive, and relevance score.

Step 3: WebSocket Heartbeat Monitoring, Format Verification, and Auto-Dismissal

Real-time assist requires a persistent WebSocket connection. You must handle ping/pong heartbeats, verify incoming message formats, and trigger automatic prompt dismissal on timeout or error to prevent UI rendering stale data.

var wsDialer = websocket.Dialer{
	HandshakeTimeout: 10 * time.Second,
	TLSClientConfig:  &tls.Config{InsecureSkipVerify: false},
}

func (d *PromptDeliverer) connectWebSocket() (*websocket.Conn, error) {
	if err := d.getAccessToken(); err != nil {
		return nil, fmt.Errorf("auth failed: %w", err)
	}

	url := fmt.Sprintf("wss://%s.platform.nicecxone.com/api/v1/agent-assist/ws", d.Config.OrgID)
	headers := http.Header{}
	headers.Set("Authorization", "Bearer "+d.token)
	headers.Set("X-NICE-Organization-ID", d.Config.OrgID)

	conn, resp, err := wsDialer.Dial(url, headers)
	if err != nil {
		return nil, fmt.Errorf("websocket dial failed: %w, status: %d", err, resp.StatusCode)
	}

	// Start heartbeat monitoring
	go d.handleHeartbeat(conn)
	go d.handleIncomingMessages(conn)

	return conn, nil
}

func (d *PromptDeliverer) handleHeartbeat(conn *websocket.Conn) {
	ticker := time.NewTicker(30 * time.Second)
	defer ticker.Stop()

	for range ticker.C {
		if err := conn.WriteMessage(websocket.PingMessage, []byte("keepalive")); err != nil {
			d.Logger.Warn("websocket ping failed", "error", err)
			conn.Close()
			return
		}
	}
}

func (d *PromptDeliverer) handleIncomingMessages(conn *websocket.Conn) {
	for {
		_, message, err := conn.ReadMessage()
		if err != nil {
			if websocket.IsUnexpectedCloseError(err, websocket.CloseGoingAway, websocket.CloseNormalClosure) {
				d.Logger.Error("websocket read error", "error", err)
			}
			return
		}

		// Format verification for incoming assist engine responses
		var payload map[string]interface{}
		if err := json.Unmarshal(message, &payload); err != nil {
			d.Logger.Warn("invalid websocket message format", "raw", string(message))
			continue
		}

		event, ok := payload["event"].(string)
		if !ok {
			d.Logger.Warn("missing event field in websocket message")
			continue
		}

		switch event {
		case "prompt_displayed":
			d.Logger.Info("ui rendering confirmed", "payload", payload)
		case "prompt_dismissed":
			d.Logger.Info("agent dismissed prompt", "payload", payload)
		case "timeout":
			// Automatic prompt dismissal trigger for safe deliver iteration
			d.sendDismissCommand(conn, payload["prompt_ref"].(string))
		}
	}
}

func (d *PromptDeliverer) sendDismissCommand(conn *websocket.Conn, promptRef string) {
	dismissPayload := map[string]interface{}{
		"action":      "dismiss",
		"prompt_ref":  promptRef,
		"reason":      "timeout_or_error",
		"timestamp":   time.Now().UTC().Format(time.RFC3339),
	}
	body, _ := json.Marshal(dismissPayload)
	conn.WriteMessage(websocket.TextMessage, body)
	d.Logger.Info("auto-dismissal triggered", "prompt_ref", promptRef)
}

The WebSocket connection uses a thirty-second ping interval to maintain connection state across CXone load balancers. The handleIncomingMessages routine verifies JSON format before processing. The timeout event triggers an automatic dismissal command to clear stale UI elements and prepare the agent interface for the next prompt iteration. All write operations are atomic relative to the connection lifecycle.

Complete Working Example

package main

import (
	"bytes"
	"fmt"
	"log/slog"
	"os"
	"time"

	"github.com/gorilla/websocket"
)

// Previous structs and methods from Steps 1-3 are included here in production.
// This main function demonstrates initialization and execution flow.

func main() {
	logger := slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{Level: slog.LevelInfo}))

	config := CXoneConfig{
		OrgID:          "your-org-id",
		ClientID:       "your-client-id",
		ClientSecret:   "your-client-secret",
		BaseURL:        "https://your-org.platform.nicecxone.com",
		WebhookURL:     "https://your-internal-kb.example.com/api/v1/assist-sync",
		RelevanceMin:   0.75,
		AgentPrefs:     map[string]bool{"agent-123": true, "agent-456": false},
	}

	deliverer := &PromptDeliverer{
		Config: config,
		Logger: logger,
	}

	prompt := AssistPrompt{
		PromptRef:        "kb-ref-98765",
		ContextMatrix:    map[string]string{"conversation_id": "conv-555", "channel": "voice"},
		DisplayDirective: "sidebar",
		Content:          "Verify customer account status before proceeding with refund. Reference policy section 4.2.",
		RelevanceScore:   0.89,
		AgentID:          "agent-123",
	}

	// REST delivery path
	if err := deliverer.deliverViaREST(prompt); err != nil {
		logger.Error("rest delivery failed", "error", err)
		os.Exit(1)
	}

	// WebSocket streaming path
	conn, err := deliverer.connectWebSocket()
	if err != nil {
		logger.Error("websocket connection failed", "error", err)
		os.Exit(1)
	}
	defer conn.Close()

	logger.Info("assist prompt deliverer initialized and streaming")

	// Keep main alive for WS operations
	select {}
}

Replace the placeholder configuration values with your CXone credentials. The service initializes the deliverer, validates the prompt, executes REST delivery with webhook synchronization, and establishes a persistent WebSocket stream for real-time updates.

Common Errors & Debugging

Error: 401 Unauthorized

• Cause: Expired OAuth token or missing agent-assist:prompt:write scope.
• Fix: Verify client credentials in CXone Admin. Ensure the token refresh grace period aligns with your delivery frequency. Add explicit scope logging during token fetch.
• Code Fix: The getAccessToken method already implements a thirty-second pre-expiry refresh. If you see repeated 401s, increase the grace period or log the token expiry timestamp.

Error: 403 Forbidden

• Cause: OAuth client lacks permissions for the Agent Assist module or the organization ID mismatch.
• Fix: Assign the Agent Assist Administrator or API Developer role to the OAuth client. Verify X-NICE-Organization-ID matches the OAuth token scope.
• Code Fix: Add slog.Error logging for 403 responses to capture the exact rejection reason from the CXone response body.

Error: 413 Payload Too Large

• Cause: Prompt content exceeds the assist engine maximum length limit.
• Fix: Enforce maxPromptLength validation before transmission. Truncate or split content at the application layer.
• Code Fix: The validatePrompt method checks len(p.Content) > maxPromptLength. Adjust the constant if CXone policy changes, but never exceed documented limits.

Error: 429 Too Many Requests

• Cause: Rate limit exceeded on prompt delivery endpoints.
• Fix: Implement exponential backoff with jitter. Track request timestamps and throttle delivery frequency per agent.
• Code Fix: Wrap client.Do() in a retry loop that checks for 429 status and sleeps for 2^attempt * time.Second before retrying.

Error: WebSocket Close Code 1006

• Cause: Abnormal closure due to network interruption or CXone load balancer timeout.
• Fix: Implement automatic reconnection logic. Monitor ping/pong latency. Re-authenticate if the session expires.
• Code Fix: Add a connection state monitor that calls connectWebSocket() when conn.ReadMessage() returns a permanent error.

Official References

• NICE CXone Agent Assist API Documentation
• CXone OAuth 2.0 Authentication Guide
• CXone WebSocket Real-Time Streaming Reference
• Gorilla WebSocket Package Documentation
• Go OAuth2 Client Credentials Flow