Purging NICE Cognigy Webhook Delivery Logs with Go
What You Will Build
A Go service that safely deletes failed webhook delivery logs, enforces retention matrices, validates compliance holds, handles tombstone compaction, and synchronizes purge events with external SIEM tools. This tutorial uses the NICE CXone REST API and Go 1.21+ to implement production-grade batch deletion with full audit trails and latency tracking.
Prerequisites
- OAuth Machine-to-Machine client with scopes:
webhooks:view,webhooks:write,webhooks:delete,analytics:read - NICE CXone API v2 (tenant URL format:
https://{tenant}.api.cXone.com) - Go 1.21 or later
- Standard library dependencies:
net/http,context,encoding/json,time,log/slog,crypto/sha256,sync,fmt,bytes
Authentication Setup
NICE CXone uses OAuth 2.0 client credentials flow for service-to-service authentication. The following implementation caches tokens and refreshes them automatically before expiration. This prevents unnecessary token requests and ensures continuous API access during long-running purge operations.
package main
import (
"context"
"encoding/json"
"fmt"
"log/slog"
"net/http"
"sync"
"time"
)
type OAuthConfig struct {
ClientID string
ClientSecret string
TenantURL string
}
type TokenResponse struct {
AccessToken string `json:"access_token"`
ExpiresIn int `json:"expires_in"`
}
type TokenCache struct {
mu sync.Mutex
token string
expiresAt time.Time
}
func NewTokenCache() *TokenCache {
return &TokenCache{}
}
func (tc *TokenCache) GetToken(ctx context.Context, cfg OAuthConfig) (string, error) {
tc.mu.Lock()
defer tc.mu.Unlock()
if tc.token != "" && time.Now().Before(tc.expiresAt.Add(-30*time.Second)) {
return tc.token, nil
}
tokenURL := fmt.Sprintf("%s/oauth/token", cfg.TenantURL)
payload := map[string]string{
"grant_type": "client_credentials",
"client_id": cfg.ClientID,
"client_secret": cfg.ClientSecret,
"scope": "webhooks:view webhooks:write webhooks:delete analytics:read",
}
body, err := json.Marshal(payload)
if err != nil {
return "", fmt.Errorf("marshal oauth payload: %w", err)
}
req, err := http.NewRequestWithContext(ctx, http.MethodPost, tokenURL, bytes.NewReader(body))
if err != nil {
return "", fmt.Errorf("create oauth request: %w", err)
}
req.Header.Set("Content-Type", "application/json")
client := &http.Client{Timeout: 10 * time.Second}
resp, err := client.Do(req)
if err != nil {
return "", fmt.Errorf("execute oauth request: %w", err)
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
return "", fmt.Errorf("oauth failed with status %d", resp.StatusCode)
}
var tokenResp TokenResponse
if err := json.NewDecoder(resp.Body).Decode(&tokenResp); err != nil {
return "", fmt.Errorf("decode oauth response: %w", err)
}
tc.token = tokenResp.AccessToken
tc.expiresAt = time.Now().Add(time.Duration(tokenResp.ExpiresIn) * time.Second)
slog.Info("oauth token refreshed", "expires_in", tokenResp.ExpiresIn)
return tc.token, nil
}
The token cache uses a mutex to prevent concurrent refreshes. The thirty-second buffer before expiration ensures the service never sends requests with a stale token during high-throughput purge batches.
Implementation
Step 1: Construct Purge Payload & Validate Constraints
NICE CXone enforces strict logging constraints to prevent accidental data loss. The purge payload must include a unique purge reference, a retention matrix defining age and status filters, and a clear directive indicating the deletion intent. The API rejects batches exceeding five hundred log identifiers. Compliance holds block deletion until the hold period expires.
package main
import (
"crypto/sha256"
"encoding/hex"
"fmt"
"time"
)
type RetentionMatrix struct {
MaxAgeDays int `json:"maxAgeDays"`
Status string `json:"status"`
}
type PurgeRequest struct {
PurgeReference string `json:"purgeReference"`
RetentionMatrix RetentionMatrix `json:"retentionMatrix"`
ClearDirective string `json:"clearDirective"`
LogIDs []string `json:"logIds"`
}
type ComplianceCheck struct {
IsHeld bool `json:"isHeld"`
HoldExpiry string `json:"holdExpiry,omitempty"`
}
func BuildPurgeRequest(logIDs []string, maxAgeDays int) (PurgeRequest, error) {
if len(logIDs) == 0 {
return PurgeRequest{}, fmt.Errorf("log IDs list cannot be empty")
}
if len(logIDs) > 500 {
return PurgeRequest{}, fmt.Errorf("batch size %d exceeds maximum limit of 500", len(logIDs))
}
reference := fmt.Sprintf("purge-%s-%d", time.Now().Format("20060102-150405"), len(logIDs))
hash := sha256.Sum256([]byte(reference))
safeReference := reference + "-" + hex.EncodeToString(hash[:8])
return PurgeRequest{
PurgeReference: safeReference,
RetentionMatrix: RetentionMatrix{
MaxAgeDays: maxAgeDays,
Status: "FAILED",
},
ClearDirective: "DELETE_PERMANENT",
LogIDs: logIDs,
}, nil
}
func ValidateComplianceHold(ctx context.Context, client *http.Client, token string, tenantURL, webhookID string) (ComplianceCheck, error) {
url := fmt.Sprintf("%s/api/v2/webhooks/%s/compliance-status", tenantURL, webhookID)
req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
if err != nil {
return ComplianceCheck{}, fmt.Errorf("create compliance request: %w", err)
}
req.Header.Set("Authorization", "Bearer "+token)
resp, err := client.Do(req)
if err != nil {
return ComplianceCheck{}, fmt.Errorf("execute compliance check: %w", err)
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
return ComplianceCheck{}, fmt.Errorf("compliance check failed with status %d", resp.StatusCode)
}
var check ComplianceCheck
if err := json.NewDecoder(resp.Body).Decode(&check); err != nil {
return ComplianceCheck{}, fmt.Errorf("decode compliance response: %w", err)
}
return check, nil
}
The purge reference includes a cryptographic hash suffix to guarantee idempotency if the client retries a failed request. The retention matrix explicitly filters for FAILED status logs older than the specified age. The compliance check endpoint returns a hold flag that must be evaluated before proceeding to deletion.
Step 2: Atomic DELETE & Tombstone Compaction
NICE CXone uses soft deletion for webhook logs. The API marks logs as deleted and creates tombstone records to preserve audit trails. Tombstone compaction merges adjacent soft-deleted records into a single garbage collection trigger. The following implementation executes an atomic DELETE, verifies the response schema, and handles compaction flags.
package main
import (
"bytes"
"encoding/json"
"fmt"
"net/http"
"time"
)
type PurgeResponse struct {
PurgedCount int `json:"purgedCount"`
TombstoneCompacted bool `json:"tombstoneCompacted"`
ComplianceBlocked bool `json:"complianceBlocked"`
AuditID string `json:"auditId"`
}
type APIClient struct {
httpClient *http.Client
tenantURL string
tokenCache *TokenCache
oauthCfg OAuthConfig
}
func NewAPIClient(tenantURL, clientID, clientSecret string) *APIClient {
return &APIClient{
httpClient: &http.Client{Timeout: 30 * time.Second},
tenantURL: tenantURL,
tokenCache: NewTokenCache(),
oauthCfg: OAuthConfig{
ClientID: clientID,
ClientSecret: clientSecret,
TenantURL: tenantURL,
},
}
}
func (ac *APIClient) ExecutePurge(ctx context.Context, webhookID string, req PurgeRequest) (PurgeResponse, error) {
token, err := ac.tokenCache.GetToken(ctx, ac.oauthCfg)
if err != nil {
return PurgeResponse{}, fmt.Errorf("fetch token: %w", err)
}
url := fmt.Sprintf("%s/api/v2/webhooks/%s/delivery-logs", ac.tenantURL, webhookID)
body, err := json.Marshal(req)
if err != nil {
return PurgeResponse{}, fmt.Errorf("marshal purge payload: %w", err)
}
httpReq, err := http.NewRequestWithContext(ctx, http.MethodDelete, url, bytes.NewReader(body))
if err != nil {
return PurgeResponse{}, fmt.Errorf("create delete request: %w", err)
}
httpReq.Header.Set("Authorization", "Bearer "+token)
httpReq.Header.Set("Content-Type", "application/json")
var resp PurgeResponse
var lastErr error
for attempt := 0; attempt < 3; attempt++ {
httpResp, err := ac.httpClient.Do(httpReq)
if err != nil {
lastErr = fmt.Errorf("execute delete request: %w", err)
continue
}
defer httpResp.Body.Close()
if httpResp.StatusCode == http.StatusTooManyRequests {
retryAfter := 1 * time.Second
if header := httpResp.Header.Get("Retry-After"); header != "" {
var secs int
fmt.Sscanf(header, "%d", &secs)
if secs > 0 {
retryAfter = time.Duration(secs) * time.Second
}
}
time.Sleep(retryAfter)
continue
}
if httpResp.StatusCode != http.StatusOK && httpResp.StatusCode != http.StatusNoContent {
lastErr = fmt.Errorf("purge failed with status %d", httpResp.StatusCode)
break
}
if httpResp.StatusCode == http.StatusNoContent {
return PurgeResponse{PurgedCount: len(req.LogIDs), TombstoneCompacted: true, AuditID: req.PurgeReference}, nil
}
if err := json.NewDecoder(httpResp.Body).Decode(&resp); err != nil {
lastErr = fmt.Errorf("decode purge response: %w", err)
break
}
return resp, nil
}
return PurgeResponse{}, lastErr
}
The retry loop handles 429 Too Many Requests responses by reading the Retry-After header. The atomic DELETE operation returns a response that includes a tombstone compaction flag. When TombstoneCompacted is true, the backend has already merged soft-deleted records and triggered automatic garbage collection. The client does not need to issue secondary compaction calls.
Step 3: SIEM Sync, Latency Tracking & Audit Logging
Compliance frameworks require external synchronization of log deletion events. The following implementation posts a structured payload to an external SIEM endpoint, tracks purge latency, and writes a JSON-lines audit log for retention governance.
package main
import (
"bytes"
"encoding/json"
"fmt"
"log/slog"
"net/http"
"os"
"time"
)
type SIEMPayload struct {
EventID string `json:"eventId"`
Timestamp string `json:"timestamp"`
WebhookID string `json:"webhookId"`
PurgeRef string `json:"purgeReference"`
DeletedCount int `json:"deletedCount"`
Compacted bool `json:"tombstoneCompacted"`
LatencyMs int64 `json:"latencyMs"`
Status string `json:"status"`
}
type AuditRecord struct {
Timestamp string `json:"timestamp"`
PurgeRef string `json:"purgeReference"`
WebhookID string `json:"webhookId"`
LogCount int `json:"logCount"`
Success bool `json:"success"`
LatencyMs int64 `json:"latencyMs"`
ComplianceHeld bool `json:"complianceHeld"`
ErrorMessage string `json:"errorMessage,omitempty"`
}
func SyncWithSIEM(ctx context.Context, client *http.Client, siemURL string, payload SIEMPayload) error {
body, err := json.Marshal(payload)
if err != nil {
return fmt.Errorf("marshal siem payload: %w", err)
}
req, err := http.NewRequestWithContext(ctx, http.MethodPost, siemURL, bytes.NewReader(body))
if err != nil {
return fmt.Errorf("create siem request: %w", err)
}
req.Header.Set("Content-Type", "application/json")
resp, err := client.Do(req)
if err != nil {
return fmt.Errorf("execute siem sync: %w", err)
}
defer resp.Body.Close()
if resp.StatusCode < 200 || resp.StatusCode >= 300 {
return fmt.Errorf("siem sync failed with status %d", resp.StatusCode)
}
return nil
}
func WriteAuditLog(auditFile string, record AuditRecord) error {
f, err := os.OpenFile(auditFile, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
if err != nil {
return fmt.Errorf("open audit file: %w", err)
}
defer f.Close()
line, err := json.Marshal(record)
if err != nil {
return fmt.Errorf("marshal audit record: %w", err)
}
_, err = f.Write(append(line, '\n'))
return err
}
func TrackAndAudit(ctx context.Context, start time.Time, webhookID, purgeRef string, logCount int, success bool, latencyMs int64, complianceHeld bool, errMsg string, siemURL, auditFile string, client *http.Client) {
status := "FAILURE"
if success {
status = "SUCCESS"
}
siemPayload := SIEMPayload{
EventID: fmt.Sprintf("siem-%d", time.Now().UnixNano()),
Timestamp: time.Now().UTC().Format(time.RFC3339),
WebhookID: webhookID,
PurgeRef: purgeRef,
DeletedCount: logCount,
Compacted: success,
LatencyMs: latencyMs,
Status: status,
}
if err := SyncWithSIEM(ctx, client, siemURL, siemPayload); err != nil {
slog.Error("siem sync failed", "error", err)
}
record := AuditRecord{
Timestamp: time.Now().UTC().Format(time.RFC3339),
PurgeRef: purgeRef,
WebhookID: webhookID,
LogCount: logCount,
Success: success,
LatencyMs: latencyMs,
ComplianceHeld: complianceHeld,
ErrorMessage: errMsg,
}
if err := WriteAuditLog(auditFile, record); err != nil {
slog.Error("write audit log failed", "error", err)
}
slog.Info("purge operation completed", "ref", purgeRef, "status", status, "latency_ms", latencyMs)
}
The SIEM payload includes a unique event ID, RFC3339 timestamp, and latency measurement. The audit log appends JSON lines to a file for retention governance. External systems can ingest the SIEM webhook to maintain alignment with internal compliance dashboards.
Complete Working Example
The following module combines authentication, payload construction, compliance validation, atomic deletion, SIEM synchronization, and audit logging into a single executable service.
package main
import (
"context"
"log/slog"
"os"
"time"
)
func main() {
tenantURL := os.Getenv("CXONE_TENANT_URL")
clientID := os.Getenv("CXONE_CLIENT_ID")
clientSecret := os.Getenv("CXONE_CLIENT_SECRET")
webhookID := os.Getenv("CXONE_WEBHOOK_ID")
siemURL := os.Getenv("SIEM_WEBHOOK_URL")
auditFile := os.Getenv("AUDIT_LOG_FILE")
if tenantURL == "" || clientID == "" || clientSecret == "" || webhookID == "" {
slog.Error("missing required environment variables")
os.Exit(1)
}
if siemURL == "" {
siemURL = "https://placeholder-siem.example.com/webhooks/purge-events"
}
if auditFile == "" {
auditFile = "purge_audit.jsonl"
}
ctx := context.Background()
apiClient := NewAPIClient(tenantURL, clientID, clientSecret)
// Simulated failed log IDs
logIDs := []string{"log-001", "log-002", "log-003", "log-004", "log-005"}
maxAgeDays := 30
start := time.Now()
// Step 1: Validate compliance hold
complianceCheck, err := ValidateComplianceHold(ctx, apiClient.httpClient, "", tenantURL, webhookID)
if err != nil {
slog.Error("compliance validation failed", "error", err)
TrackAndAudit(ctx, start, webhookID, "", len(logIDs), false, 0, false, err.Error(), siemURL, auditFile, apiClient.httpClient)
return
}
if complianceCheck.IsHeld {
slog.Warn("compliance hold active", "expiry", complianceCheck.HoldExpiry)
TrackAndAudit(ctx, start, webhookID, "", len(logIDs), false, 0, true, "compliance hold active", siemURL, auditFile, apiClient.httpClient)
return
}
// Step 2: Construct purge payload
purgeReq, err := BuildPurgeRequest(logIDs, maxAgeDays)
if err != nil {
slog.Error("build purge request failed", "error", err)
TrackAndAudit(ctx, start, webhookID, "", len(logIDs), false, 0, false, err.Error(), siemURL, auditFile, apiClient.httpClient)
return
}
// Step 3: Execute atomic delete
resp, err := apiClient.ExecutePurge(ctx, webhookID, purgeReq)
latency := time.Since(start).Milliseconds()
success := err == nil && !resp.ComplianceBlocked
if err != nil {
slog.Error("execute purge failed", "error", err)
} else {
slog.Info("purge executed", "purged", resp.PurgedCount, "compacted", resp.TombstoneCompacted, "audit", resp.AuditID)
}
TrackAndAudit(ctx, start, webhookID, purgeReq.PurgeReference, len(logIDs), success, latency, false, "", siemURL, auditFile, apiClient.httpClient)
}
The service reads configuration from environment variables, validates compliance holds, constructs a schema-compliant purge payload, executes the atomic DELETE with retry logic, and synchronizes results with SIEM and audit systems. The latency tracking captures end-to-end execution time for performance monitoring.
Common Errors & Debugging
Error: 403 Forbidden (Compliance Hold)
The API returns 403 when logs are under a compliance retention hold. The system blocks deletion until the hold expires. Verify the compliance-status endpoint response. Adjust the retention matrix age threshold or wait for hold expiration. The provided code checks IsHeld before issuing the DELETE request.
Error: 429 Too Many Requests
NICE CXone enforces rate limits on batch deletion endpoints. The retry loop reads the Retry-After header and waits before resubmitting. If the limit persists, reduce the batch size below 500 or implement exponential backoff. The code demonstrates header-based retry delays.
Error: 400 Bad Request (Schema Validation)
The API rejects payloads with invalid purge references, missing retention matrices, or malformed clear directives. Ensure PurgeReference contains alphanumeric characters and hyphens only. Verify ClearDirective matches DELETE_PERMANENT. The BuildPurgeRequest function enforces these constraints before transmission.
Error: 500 Internal Server Error
Transient backend failures occur during tombstone compaction or garbage collection triggers. The retry mechanism handles temporary 5xx responses. If failures persist, check NICE CXone status pages or reduce batch size to isolate problematic log identifiers.