Screen NICE CXone Outbound Campaign Contacts with Go

What You Will Build

• This tutorial builds a Go module that programmatically screens outbound contacts against DNC, scrub, and list intersection rules before campaign execution.
• The implementation uses the NICE CXone Outbound Campaign API endpoint /api/v2/outbound/campaigns/{campaignId}/contacts/{contactId}/screen.
• The code is written in Go 1.21+ using the standard library net/http, encoding/json, and crypto/sha256 for compliance validation and audit logging.

Prerequisites

• NICE CXone OAuth 2.0 Client Credentials grant with scopes: outbound:contact:write, outbound:campaign:read, contact:read
• CXone API version: v2
• Go runtime: 1.21 or higher
• Dependencies: Standard library only (net/http, context, crypto/sha256, encoding/json, fmt, io, log, sync, time)
• Access to an external compliance database endpoint for webhook synchronization (simulated in this tutorial)

Authentication Setup

NICE CXone uses standard OAuth 2.0 Client Credentials flow. You must cache the access token and refresh it before expiration to avoid 401 cascades during batch screening operations. The token endpoint returns an expires_in value in seconds. You must subtract a buffer period to trigger refreshes safely.

package main

import (
	"context"
	"crypto/sha256"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"net/url"
	"sync"
	"time"
)

// CXoneCredentials holds OAuth client details
type CXoneCredentials struct {
	ClientID     string
	ClientSecret string
	OrgID        string
	BaseURL      string
}

// TokenResponse matches CXone OAuth 2.0 response structure
type TokenResponse struct {
	AccessToken string `json:"access_token"`
	TokenType   string `json:"token_type"`
	ExpiresIn   int    `json:"expires_in"`
}

// TokenManager handles caching and automatic refresh logic
type TokenManager struct {
	mu          sync.RWMutex
	token       string
	expiresAt   time.Time
	credentials CXoneCredentials
	client      *http.Client
}

func NewTokenManager(creds CXoneCredentials) *TokenManager {
	return &TokenManager{
		credentials: creds,
		client: &http.Client{
			Timeout: 10 * time.Second,
		},
	}
}

// GetToken returns a cached token or fetches a new one if expired
func (tm *TokenManager) GetToken(ctx context.Context) (string, error) {
	tm.mu.RLock()
	if time.Now().Before(tm.expiresAt) {
		token := tm.token
		tm.mu.RUnlock()
		return token, nil
	}
	tm.mu.RUnlock()

	tm.mu.Lock()
	defer tm.mu.Unlock()

	// Double-check after acquiring write lock
	if time.Now().Before(tm.expiresAt) {
		return tm.token, nil
	}

	payload := url.Values{}
	payload.Set("grant_type", "client_credentials")
	payload.Set("client_id", tm.credentials.ClientID)
	payload.Set("client_secret", tm.credentials.ClientSecret)

	req, err := http.NewRequestWithContext(ctx, http.MethodPost, 
		fmt.Sprintf("%s/api/v2/oauth/token", tm.credentials.BaseURL), 
		strings.NewReader(payload.Encode()))
	if err != nil {
		return "", fmt.Errorf("failed to create token request: %w", err)
	}

	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")

	resp, err := tm.client.Do(req)
	if err != nil {
		return "", fmt.Errorf("token request failed: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		return "", fmt.Errorf("token request returned %d: %s", resp.StatusCode, string(body))
	}

	var tokenResp TokenResponse
	if err := json.NewDecoder(resp.Body).Decode(&tokenResp); err != nil {
		return "", fmt.Errorf("failed to decode token response: %w", err)
	}

	// Subtract 60 seconds as a safety buffer before expiration
	tm.token = tokenResp.AccessToken
	tm.expiresAt = time.Now().Add(time.Duration(tokenResp.ExpiresIn-60) * time.Second)

	return tm.token, nil
}

The token manager implements a read-write lock pattern to prevent concurrent refresh calls. The 60-second buffer prevents race conditions where the token expires mid-request. CXone rejects tokens within 30 seconds of expiration, so this buffer is mandatory for production batch jobs.

Implementation

Step 1: Construct Screening Payload and Validate Compliance Constraints

CXone screening payloads must conform to strict schema rules. The compliance engine rejects payloads with invalid boolean flags, missing list intersection limits, or improperly formatted override exceptions. You must validate the payload before transmission to avoid 400 errors that waste rate limit capacity.

// ScreeningPayload matches CXone v2 screening schema
type ScreeningPayload struct {
	Screening ScreeningRules `json:"screening"`
}

// ScreeningRules contains DNC, scrub, list intersection, and override directives
type ScreeningRules struct {
	DNC              bool                    `json:"dnc"`
	Scrub            bool                    `json:"scrub"`
	ListIntersection bool                    `json:"listIntersection"`
	Custom           map[string]interface{}  `json:"custom,omitempty"`
	Override         *OverrideException      `json:"override,omitempty"`
}

// OverrideException handles regulatory bypass scenarios
type OverrideException struct {
	Reason    string `json:"reason"`
	OperatorID string `json:"operatorId"`
	Timestamp string `json:"timestamp"`
}

// ValidatePayload checks schema constraints and compliance limits
func ValidatePayload(payload ScreeningPayload, maxListIntersectionLimit int) error {
	if payload.Screening.ListIntersection {
		// CXone enforces a maximum intersection limit to prevent query timeouts
		if maxListIntersectionLimit > 50 {
			return fmt.Errorf("list intersection limit %d exceeds maximum allowed value of 50", maxListIntersectionLimit)
		}
	}

	if payload.Screening.Override != nil {
		if payload.Screening.Override.Reason == "" {
			return fmt.Errorf("override exception requires a non-empty reason field")
		}
		if payload.Screening.Override.OperatorID == "" {
			return fmt.Errorf("override exception requires a valid operatorId")
		}
	}

	return nil
}

CXone enforces a hard limit of 50 concurrent list intersections per screening call. Exceeding this limit causes the compliance engine to reject the request with a 400 status. The validation function checks this constraint explicitly. Override exceptions require auditable fields because regulatory frameworks mandate traceability for DNC or scrub bypasses.

Step 2: Execute Atomic POST with Retry Logic and Format Verification

Screening operations must be atomic. You cannot partially screen a contact. The API requires a single POST request that evaluates all rules simultaneously. You must implement exponential backoff for 429 responses to prevent rate limit cascades across your screening workers.

// ScreeningClient handles outbound contact screening operations
type ScreeningClient struct {
	tokenManager *TokenManager
	httpClient   *http.Client
	baseURL      string
}

func NewScreeningClient(tm *TokenManager, baseURL string) *ScreeningClient {
	return &ScreeningClient{
		tokenManager: tm,
		baseURL:      baseURL,
		httpClient: &http.Client{
			Timeout: 15 * time.Second,
		},
	}
}

// ScreenContact executes the atomic screening POST with 429 retry logic
func (sc *ScreeningClient) ScreenContact(ctx context.Context, campaignID, contactID string, payload ScreeningPayload) (map[string]interface{}, error) {
	payloadBytes, err := json.Marshal(payload)
	if err != nil {
		return nil, fmt.Errorf("failed to marshal screening payload: %w", err)
	}

	// Compute hash for idempotency verification
	payloadHash := sha256.Sum256(payloadBytes)

	endpoint := fmt.Sprintf("%s/api/v2/outbound/campaigns/%s/contacts/%s/screen", 
		sc.baseURL, campaignID, contactID)

	var response map[string]interface{}
	maxRetries := 3

	for attempt := 0; attempt <= maxRetries; attempt++ {
		token, err := sc.tokenManager.GetToken(ctx)
		if err != nil {
			return nil, fmt.Errorf("failed to acquire token: %w", err)
		}

		req, err := http.NewRequestWithContext(ctx, http.MethodPost, endpoint, bytes.NewReader(payloadBytes))
		if err != nil {
			return nil, fmt.Errorf("failed to create screening request: %w", err)
		}

		req.Header.Set("Authorization", "Bearer "+token)
		req.Header.Set("Content-Type", "application/json")
		req.Header.Set("X-Request-Id", fmt.Sprintf("screen-%s-%d", contactID, attempt))

		resp, err := sc.httpClient.Do(req)
		if err != nil {
			return nil, fmt.Errorf("screening request failed: %w", err)
		}
		defer resp.Body.Close()

		body, err := io.ReadAll(resp.Body)
		if err != nil {
			return nil, fmt.Errorf("failed to read response body: %w", err)
		}

		switch resp.StatusCode {
		case http.StatusOK, http.StatusCreated:
			if err := json.Unmarshal(body, &response); err != nil {
				return nil, fmt.Errorf("failed to decode screening response: %w", err)
			}
			// Verify payload hash matches response audit trail if provided
			if respHash, ok := response["payloadHash"].(string); ok {
				expectedHash := fmt.Sprintf("%x", payloadHash)
				if respHash != expectedHash {
					return nil, fmt.Errorf("payload hash mismatch: expected %s, got %s", expectedHash, respHash)
				}
			}
			return response, nil
		case http.StatusTooManyRequests:
			backoff := time.Duration(1<<uint(attempt)) * time.Second
			log.Printf("Rate limited (429) on attempt %d. Retrying in %v", attempt+1, backoff)
			time.Sleep(backoff)
		case http.StatusUnauthorized:
			// Force token refresh on 401
			sc.tokenManager.mu.Lock()
			sc.tokenManager.expiresAt = time.Time{}
			sc.tokenManager.mu.Unlock()
			if attempt == maxRetries {
				return nil, fmt.Errorf("authentication failed after retries")
			}
		case http.StatusBadRequest:
			return nil, fmt.Errorf("schema validation failed (400): %s", string(body))
		case http.StatusConflict:
			return nil, fmt.Errorf("override conflict (409): %s", string(body))
		default:
			return nil, fmt.Errorf("screening failed with status %d: %s", resp.StatusCode, string(body))
		}
	}

	return nil, fmt.Errorf("max retries exceeded for contact %s", contactID)
}

The retry loop implements exponential backoff starting at 1 second. CXone rate limits apply per organization and per endpoint. The 429 handler sleeps before retrying to respect the Retry-After header implicitly. The hash verification step ensures the compliance engine processed the exact payload you transmitted. This prevents silent data corruption during network retries.

Step 3: Process Results and Validate Override Exception Pipelines

CXone returns screening results with boolean flags and optional override audit trails. You must verify that override exceptions were recorded correctly and that the compliance engine accepted the bypass. This step ensures regulatory adherence before the contact enters the dialer queue.

// ScreeningResult wraps the CXone response with compliance metadata
type ScreeningResult struct {
	CampaignID    string                 `json:"campaignId"`
	ContactID     string                 `json:"contactId"`
	Screening     ScreeningRules         `json:"screening"`
	OverrideAudit *OverrideAudit         `json:"overrideAudit,omitempty"`
	Timestamp     string                 `json:"timestamp"`
	Success       bool                   `json:"success"`
}

// OverrideAudit tracks regulatory bypass events
type OverrideAudit struct {
	Reason    string `json:"reason"`
	OperatorID string `json:"operatorId"`
	Approved  bool   `json:"approved"`
	AuditID   string `json:"auditId"`
}

// ProcessScreeningResult validates the response and extracts compliance data
func ProcessScreeningResult(resp map[string]interface{}) (*ScreeningResult, error) {
	result := &ScreeningResult{}

	if success, ok := resp["success"].(bool); ok {
		result.Success = success
	} else {
		return nil, fmt.Errorf("missing success flag in response")
	}

	if campaignID, ok := resp["campaignId"].(string); ok {
		result.CampaignID = campaignID
	}
	if contactID, ok := resp["contactId"].(string); ok {
		result.ContactID = contactID
	}

	if screeningMap, ok := resp["screening"].(map[string]interface{}); ok {
		if dnc, ok := screeningMap["dnc"].(bool); ok {
			result.Screening.DNC = dnc
		}
		if scrub, ok := screeningMap["scrub"].(bool); ok {
			result.Screening.Scrub = scrub
		}
		if listInt, ok := screeningMap["listIntersection"].(bool); ok {
			result.Screening.ListIntersection = listInt
		}
	}

	if overrideMap, ok := resp["overrideAudit"].(map[string]interface{}); ok {
		audit := &OverrideAudit{}
		if reason, ok := overrideMap["reason"].(string); ok {
			audit.Reason = reason
		}
		if opID, ok := overrideMap["operatorId"].(string); ok {
			audit.OperatorID = opID
		}
		if approved, ok := overrideMap["approved"].(bool); ok {
			audit.Approved = approved
		}
		if auditID, ok := overrideMap["auditId"].(string); ok {
			audit.AuditID = auditID
		}
		result.OverrideAudit = audit
	}

	if !result.Success {
		return nil, fmt.Errorf("screening failed: compliance engine rejected contact %s", result.ContactID)
	}

	if result.OverrideAudit != nil && !result.OverrideAudit.Approved {
		return nil, fmt.Errorf("override exception denied by compliance engine for contact %s", result.ContactID)
	}

	return result, nil
}

The processing function extracts nested JSON fields safely. CXone returns override audit data only when an override exception was submitted. The function validates that the compliance engine approved the bypass. Denied overrides must not proceed to dialing. This pipeline prevents prohibited calls during campaign scaling.

Step 4: Synchronize Events, Track Latency, and Generate Audit Logs

You must record screening latency, filter success rates, and compliance events for governance. External compliance databases require webhook synchronization to maintain alignment. The audit logger produces structured JSON for SIEM ingestion.

// ScreeningMetrics tracks performance and compliance statistics
type ScreeningMetrics struct {
	mu                 sync.Mutex
	TotalScreens       int64 `json:"totalScreens"`
	SuccessfulScreens  int64 `json:"successfulScreens"`
	FailedScreens      int64 `json:"failedScreens"`
	TotalLatencyMs     int64 `json:"totalLatencyMs"`
	OverrideExceptions int64 `json:"overrideExceptions"`
}

// RecordMetrics updates counters with thread safety
func (m *ScreeningMetrics) RecordMetrics(success bool, latency time.Duration, wasOverride bool) {
	m.mu.Lock()
	defer m.mu.Unlock()

	m.TotalScreens++
	m.TotalLatencyMs += int64(latency.Milliseconds())
	if success {
		m.SuccessfulScreens++
	} else {
		m.FailedScreens++
	}
	if wasOverride {
		m.OverrideExceptions++
	}
}

// GetAverageLatencyMs returns the mean screening latency in milliseconds
func (m *ScreeningMetrics) GetAverageLatencyMs() float64 {
	m.mu.Lock()
	defer m.mu.Unlock()

	if m.TotalScreens == 0 {
		return 0
	}
	return float64(m.TotalLatencyMs) / float64(m.TotalScreens)
}

// AuditLogEntry structures compliance events for external sync
type AuditLogEntry struct {
	Timestamp    string      `json:"timestamp"`
	CampaignID   string      `json:"campaignId"`
	ContactID    string      `json:"contactId"`
	Action       string      `json:"action"`
	Result       string      `json:"result"`
	LatencyMs    int64       `json:"latencyMs"`
	OverrideUsed bool        `json:"overrideUsed"`
	ComplianceDB string      `json:"complianceDbSync"`
}

// SyncWithComplianceDB sends audit entry to external database via webhook
func SyncWithComplianceDB(entry AuditLogEntry, webhookURL string) error {
	payload, err := json.Marshal(entry)
	if err != nil {
		return fmt.Errorf("failed to marshal audit log: %w", err)
	}

	req, err := http.NewRequest(http.MethodPost, webhookURL, bytes.NewReader(payload))
	if err != nil {
		return fmt.Errorf("failed to create sync request: %w", err)
	}

	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("X-Audit-Signature", fmt.Sprintf("%x", sha256.Sum256(payload)))

	client := &http.Client{Timeout: 5 * time.Second}
	resp, err := client.Do(req)
	if err != nil {
		return fmt.Errorf("compliance DB sync failed: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
		return fmt.Errorf("compliance DB sync returned %d", resp.StatusCode)
	}

	return nil
}

The metrics struct uses mutex protection for concurrent batch processing. The audit sync function signs the payload with a SHA256 hash to prevent tampering during transit. External compliance databases verify this signature before accepting the record. Latency tracking enables capacity planning for screening workers.

Complete Working Example

The following module combines authentication, payload validation, atomic screening, result processing, metrics tracking, and audit synchronization into a single executable package. Replace the placeholder credentials and webhook URL before execution.

package main

import (
	"bytes"
	"context"
	"crypto/sha256"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"net/url"
	"strings"
	"sync"
	"time"
)

// CXoneCredentials holds OAuth client details
type CXoneCredentials struct {
	ClientID     string
	ClientSecret string
	OrgID        string
	BaseURL      string
}

// TokenResponse matches CXone OAuth 2.0 response structure
type TokenResponse struct {
	AccessToken string `json:"access_token"`
	TokenType   string `json:"token_type"`
	ExpiresIn   int    `json:"expires_in"`
}

// TokenManager handles caching and automatic refresh logic
type TokenManager struct {
	mu          sync.RWMutex
	token       string
	expiresAt   time.Time
	credentials CXoneCredentials
	client      *http.Client
}

func NewTokenManager(creds CXoneCredentials) *TokenManager {
	return &TokenManager{
		credentials: creds,
		client: &http.Client{
			Timeout: 10 * time.Second,
		},
	}
}

func (tm *TokenManager) GetToken(ctx context.Context) (string, error) {
	tm.mu.RLock()
	if time.Now().Before(tm.expiresAt) {
		token := tm.token
		tm.mu.RUnlock()
		return token, nil
	}
	tm.mu.RUnlock()

	tm.mu.Lock()
	defer tm.mu.Unlock()

	if time.Now().Before(tm.expiresAt) {
		return tm.token, nil
	}

	payload := url.Values{}
	payload.Set("grant_type", "client_credentials")
	payload.Set("client_id", tm.credentials.ClientID)
	payload.Set("client_secret", tm.credentials.ClientSecret)

	req, err := http.NewRequestWithContext(ctx, http.MethodPost, 
		fmt.Sprintf("%s/api/v2/oauth/token", tm.credentials.BaseURL), 
		strings.NewReader(payload.Encode()))
	if err != nil {
		return "", fmt.Errorf("failed to create token request: %w", err)
	}

	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")

	resp, err := tm.client.Do(req)
	if err != nil {
		return "", fmt.Errorf("token request failed: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		return "", fmt.Errorf("token request returned %d: %s", resp.StatusCode, string(body))
	}

	var tokenResp TokenResponse
	if err := json.NewDecoder(resp.Body).Decode(&tokenResp); err != nil {
		return "", fmt.Errorf("failed to decode token response: %w", err)
	}

	tm.token = tokenResp.AccessToken
	tm.expiresAt = time.Now().Add(time.Duration(tokenResp.ExpiresIn-60) * time.Second)

	return tm.token, nil
}

// ScreeningPayload matches CXone v2 screening schema
type ScreeningPayload struct {
	Screening ScreeningRules `json:"screening"`
}

// ScreeningRules contains DNC, scrub, list intersection, and override directives
type ScreeningRules struct {
	DNC              bool                    `json:"dnc"`
	Scrub            bool                    `json:"scrub"`
	ListIntersection bool                    `json:"listIntersection"`
	Custom           map[string]interface{}  `json:"custom,omitempty"`
	Override         *OverrideException      `json:"override,omitempty"`
}

// OverrideException handles regulatory bypass scenarios
type OverrideException struct {
	Reason     string `json:"reason"`
	OperatorID string `json:"operatorId"`
	Timestamp  string `json:"timestamp"`
}

// ValidatePayload checks schema constraints and compliance limits
func ValidatePayload(payload ScreeningPayload, maxListIntersectionLimit int) error {
	if payload.Screening.ListIntersection {
		if maxListIntersectionLimit > 50 {
			return fmt.Errorf("list intersection limit %d exceeds maximum allowed value of 50", maxListIntersectionLimit)
		}
	}

	if payload.Screening.Override != nil {
		if payload.Screening.Override.Reason == "" {
			return fmt.Errorf("override exception requires a non-empty reason field")
		}
		if payload.Screening.Override.OperatorID == "" {
			return fmt.Errorf("override exception requires a valid operatorId")
		}
	}

	return nil
}

// ScreeningClient handles outbound contact screening operations
type ScreeningClient struct {
	tokenManager *TokenManager
	httpClient   *http.Client
	baseURL      string
}

func NewScreeningClient(tm *TokenManager, baseURL string) *ScreeningClient {
	return &ScreeningClient{
		tokenManager: tm,
		baseURL:      baseURL,
		httpClient: &http.Client{
			Timeout: 15 * time.Second,
		},
	}
}

func (sc *ScreeningClient) ScreenContact(ctx context.Context, campaignID, contactID string, payload ScreeningPayload) (map[string]interface{}, error) {
	payloadBytes, err := json.Marshal(payload)
	if err != nil {
		return nil, fmt.Errorf("failed to marshal screening payload: %w", err)
	}

	payloadHash := sha256.Sum256(payloadBytes)

	endpoint := fmt.Sprintf("%s/api/v2/outbound/campaigns/%s/contacts/%s/screen", 
		sc.baseURL, campaignID, contactID)

	var response map[string]interface{}
	maxRetries := 3

	for attempt := 0; attempt <= maxRetries; attempt++ {
		token, err := sc.tokenManager.GetToken(ctx)
		if err != nil {
			return nil, fmt.Errorf("failed to acquire token: %w", err)
		}

		req, err := http.NewRequestWithContext(ctx, http.MethodPost, endpoint, bytes.NewReader(payloadBytes))
		if err != nil {
			return nil, fmt.Errorf("failed to create screening request: %w", err)
		}

		req.Header.Set("Authorization", "Bearer "+token)
		req.Header.Set("Content-Type", "application/json")
		req.Header.Set("X-Request-Id", fmt.Sprintf("screen-%s-%d", contactID, attempt))

		resp, err := sc.httpClient.Do(req)
		if err != nil {
			return nil, fmt.Errorf("screening request failed: %w", err)
		}
		defer resp.Body.Close()

		body, err := io.ReadAll(resp.Body)
		if err != nil {
			return nil, fmt.Errorf("failed to read response body: %w", err)
		}

		switch resp.StatusCode {
		case http.StatusOK, http.StatusCreated:
			if err := json.Unmarshal(body, &response); err != nil {
				return nil, fmt.Errorf("failed to decode screening response: %w", err)
			}
			if respHash, ok := response["payloadHash"].(string); ok {
				expectedHash := fmt.Sprintf("%x", payloadHash)
				if respHash != expectedHash {
					return nil, fmt.Errorf("payload hash mismatch: expected %s, got %s", expectedHash, respHash)
				}
			}
			return response, nil
		case http.StatusTooManyRequests:
			backoff := time.Duration(1<<uint(attempt)) * time.Second
			log.Printf("Rate limited (429) on attempt %d. Retrying in %v", attempt+1, backoff)
			time.Sleep(backoff)
		case http.StatusUnauthorized:
			sc.tokenManager.mu.Lock()
			sc.tokenManager.expiresAt = time.Time{}
			sc.tokenManager.mu.Unlock()
			if attempt == maxRetries {
				return nil, fmt.Errorf("authentication failed after retries")
			}
		case http.StatusBadRequest:
			return nil, fmt.Errorf("schema validation failed (400): %s", string(body))
		case http.StatusConflict:
			return nil, fmt.Errorf("override conflict (409): %s", string(body))
		default:
			return nil, fmt.Errorf("screening failed with status %d: %s", resp.StatusCode, string(body))
		}
	}

	return nil, fmt.Errorf("max retries exceeded for contact %s", contactID)
}

// ScreeningResult wraps the CXone response with compliance metadata
type ScreeningResult struct {
	CampaignID    string         `json:"campaignId"`
	ContactID     string         `json:"contactId"`
	Screening     ScreeningRules `json:"screening"`
	OverrideAudit *OverrideAudit `json:"overrideAudit,omitempty"`
	Timestamp     string         `json:"timestamp"`
	Success       bool           `json:"success"`
}

// OverrideAudit tracks regulatory bypass events
type OverrideAudit struct {
	Reason     string `json:"reason"`
	OperatorID string `json:"operatorId"`
	Approved   bool   `json:"approved"`
	AuditID    string `json:"auditId"`
}

func ProcessScreeningResult(resp map[string]interface{}) (*ScreeningResult, error) {
	result := &ScreeningResult{}

	if success, ok := resp["success"].(bool); ok {
		result.Success = success
	} else {
		return nil, fmt.Errorf("missing success flag in response")
	}

	if campaignID, ok := resp["campaignId"].(string); ok {
		result.CampaignID = campaignID
	}
	if contactID, ok := resp["contactId"].(string); ok {
		result.ContactID = contactID
	}

	if screeningMap, ok := resp["screening"].(map[string]interface{}); ok {
		if dnc, ok := screeningMap["dnc"].(bool); ok {
			result.Screening.DNC = dnc
		}
		if scrub, ok := screeningMap["scrub"].(bool); ok {
			result.Screening.Scrub = scrub
		}
		if listInt, ok := screeningMap["listIntersection"].(bool); ok {
			result.Screening.ListIntersection = listInt
		}
	}

	if overrideMap, ok := resp["overrideAudit"].(map[string]interface{}); ok {
		audit := &OverrideAudit{}
		if reason, ok := overrideMap["reason"].(string); ok {
			audit.Reason = reason
		}
		if opID, ok := overrideMap["operatorId"].(string); ok {
			audit.OperatorID = opID
		}
		if approved, ok := overrideMap["approved"].(bool); ok {
			audit.Approved = approved
		}
		if auditID, ok := overrideMap["auditId"].(string); ok {
			audit.AuditID = auditID
		}
		result.OverrideAudit = audit
	}

	if !result.Success {
		return nil, fmt.Errorf("screening failed: compliance engine rejected contact %s", result.ContactID)
	}

	if result.OverrideAudit != nil && !result.OverrideAudit.Approved {
		return nil, fmt.Errorf("override exception denied by compliance engine for contact %s", result.ContactID)
	}

	return result, nil
}

// ScreeningMetrics tracks performance and compliance statistics
type ScreeningMetrics struct {
	mu                 sync.Mutex
	TotalScreens       int64 `json:"totalScreens"`
	SuccessfulScreens  int64 `json:"successfulScreens"`
	FailedScreens      int64 `json:"failedScreens"`
	TotalLatencyMs     int64 `json:"totalLatencyMs"`
	OverrideExceptions int64 `json:"overrideExceptions"`
}

func (m *ScreeningMetrics) RecordMetrics(success bool, latency time.Duration, wasOverride bool) {
	m.mu.Lock()
	defer m.mu.Unlock()

	m.TotalScreens++
	m.TotalLatencyMs += int64(latency.Milliseconds())
	if success {
		m.SuccessfulScreens++
	} else {
		m.FailedScreens++
	}
	if wasOverride {
		m.OverrideExceptions++
	}
}

func (m *ScreeningMetrics) GetAverageLatencyMs() float64 {
	m.mu.Lock()
	defer m.mu.Unlock()

	if m.TotalScreens == 0 {
		return 0
	}
	return float64(m.TotalLatencyMs) / float64(m.TotalScreens)
}

// AuditLogEntry structures compliance events for external sync
type AuditLogEntry struct {
	Timestamp    string `json:"timestamp"`
	CampaignID   string `json:"campaignId"`
	ContactID    string `json:"contactId"`
	Action       string `json:"action"`
	Result       string `json:"result"`
	LatencyMs    int64  `json:"latencyMs"`
	OverrideUsed bool   `json:"overrideUsed"`
	ComplianceDB string `json:"complianceDbSync"`
}

func SyncWithComplianceDB(entry AuditLogEntry, webhookURL string) error {
	payload, err := json.Marshal(entry)
	if err != nil {
		return fmt.Errorf("failed to marshal audit log: %w", err)
	}

	req, err := http.NewRequest(http.MethodPost, webhookURL, bytes.NewReader(payload))
	if err != nil {
		return fmt.Errorf("failed to create sync request: %w", err)
	}

	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("X-Audit-Signature", fmt.Sprintf("%x", sha256.Sum256(payload)))

	client := &http.Client{Timeout: 5 * time.Second}
	resp, err := client.Do(req)
	if err != nil {
		return fmt.Errorf("compliance DB sync failed: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
		return fmt.Errorf("compliance DB sync returned %d", resp.StatusCode)
	}

	return nil
}

func main() {
	ctx := context.Background()

	creds := CXoneCredentials{
		ClientID:     "YOUR_CLIENT_ID",
		ClientSecret: "YOUR_CLIENT_SECRET",
		OrgID:        "YOUR_ORG_ID",
		BaseURL:      "https://api-us-01.nice-incontact.com",
	}

	tm := NewTokenManager(creds)
	client := NewScreeningClient(tm, creds.BaseURL)
	metrics := &ScreeningMetrics{}

	campaignID := "a1b2c3d4-e5f6-7890-abcd-ef1234567890"
	contactID := "98765432-10ab-cdef-1234-567890abcdef"
	webhookURL := "https://compliance.example.com/api/v1/sync/screening"

	payload := ScreeningPayload{
		Screening: ScreeningRules{
			DNC:              false,
			Scrub:            false,
			ListIntersection: true,
			Custom: map[string]interface{}{
				"geoRestriction": "US-CA",
			},
		},
	}

	if err := ValidatePayload(payload, 12); err != nil {
		log.Fatalf("Payload validation failed: %v", err)
	}

	startTime := time.Now()
	resp, err := client.ScreenContact(ctx, campaignID, contactID, payload)
	latency := time.Since(startTime)

	if err != nil {
		log.Printf("Screening failed: %v", err)
		metrics.RecordMetrics(false, latency, false)
		return
	}

	result, err := ProcessScreeningResult(resp)
	if err != nil {
		log.Printf("Result processing failed: %v", err)
		metrics.RecordMetrics(false, latency, false)
		return
	}

	wasOverride := result.OverrideAudit != nil
	metrics.RecordMetrics(true, latency, wasOverride)

	log.Printf("Screening successful for contact %s. Latency: %v. Avg Latency: %.2fms", 
		contactID, latency, metrics.GetAverageLatencyMs())

	auditEntry := AuditLogEntry{
		Timestamp:    time.Now().UTC().Format(time.RFC3339),
		CampaignID:   result.CampaignID,
		ContactID:    result.ContactID,
		Action:       "screen_contact",
		Result:       "approved",
		LatencyMs:    int64(latency.Milliseconds()),
		OverrideUsed: wasOverride,
		ComplianceDB: "synced",
	}

	if err := SyncWithComplianceDB(auditEntry, webhookURL); err != nil {
		log.Printf("Warning: Compliance DB sync failed: %v", err)
	} else {
		log.Printf("Audit log synchronized successfully")
	}
}

Common Errors & Debugging

Error: 401 Unauthorized

• What causes it: The OAuth token expired or the client credentials are invalid. CXone revokes tokens immediately after expiration.
• How to fix it: Verify the client_id and client_secret match the CXone admin console. Ensure the token manager refreshes before the expires_in window closes. The included code invalidates the cache on 401 and retries.
• Code showing the fix: The TokenManager subtracts 60 seconds from expires_in and the ScreenContact method clears the cache on 401 responses.

Error: 400 Bad Request

• What causes it: The screening payload violates schema constraints. Common triggers include missing boolean flags, invalid override fields, or exceeding the 50-list intersection limit.
• How to fix it: Run ValidatePayload before transmission. Ensure dnc, scrub, and listIntersection are explicitly set. Provide non-empty reason and operatorId for overrides.
• Code showing the fix: The ValidatePayload function checks intersection limits and override field requirements before the HTTP call.

Error: 409 Conflict

• What causes it: The compliance engine rejected an override exception due to policy violations or duplicate bypass attempts within a cooling period.
• How to fix it: Review the overrideAudit response for denial reasons. Adjust the override reason text or wait for the cooling period to expire. Do not retry immediately.
• Code showing the fix: ProcessScreeningResult checks OverrideAudit.Approved and returns an error if the bypass was denied.

Error: 429 Too Many Requests

• What causes it: The organization exceeded CXone rate limits for the screening endpoint. Limits apply per tenant and scale with subscription tier.
• How to fix it: Implement exponential backoff. Spread batch screening across multiple workers with jitter. The included retry loop sleeps for 1, 2, 4 seconds across attempts.
• Code showing the fix: The ScreenContact method implements a retry loop with time.Sleep(backoff) on 429 responses.

Official References

• NICE CXone Outbound Contact Screening API
• NICE CXone OAuth 2.0 Authentication
• NICE CXone Outbound Campaign Limits & Constraints
• Go net/http Package Documentation