Replaying NICE Cognigy Conversation Logs via REST API with Go
What You Will Build
- A production-grade Go replay engine that fetches historical conversation logs, constructs simulation payloads, validates against analytics constraints, executes replays, and synchronizes results with external test harnesses.
- This implementation uses the NICE Cognigy REST API v2 endpoints for logs, replay execution, and analytics constraints.
- The tutorial covers Go 1.21+ with standard library HTTP clients, JSON serialization, exponential backoff retry logic, and structured audit logging.
Prerequisites
- OAuth 2.0 Client Credentials grant type with scopes:
logs:read,replay:execute,analytics:read,webhooks:notify - Cognigy API v2 access enabled on your tenant
- Go runtime 1.21 or higher
- No external dependencies required; the implementation uses
net/http,encoding/json,time,sync,log/slog, andfmt - A configured external webhook receiver URL for test harness synchronization
Authentication Setup
Cognigy uses OAuth 2.0 Client Credentials for machine-to-machine API access. The following implementation caches tokens, enforces mutex safety, and refreshes before expiration.
package main
import (
"bytes"
"context"
"encoding/json"
"fmt"
"net/http"
"sync"
"time"
)
type OAuthConfig struct {
BaseURL string
ClientID string
ClientSecret string
GrantType string
Scopes []string
}
type TokenResponse struct {
AccessToken string `json:"access_token"`
TokenType string `json:"token_type"`
ExpiresIn int64 `json:"expires_in"`
}
type TokenCache struct {
mu sync.Mutex
token string
expiresAt time.Time
refreshFunc func() (string, error)
}
func NewTokenCache(refreshFunc func() (string, error)) *TokenCache {
return &TokenCache{refreshFunc: refreshFunc}
}
func (tc *TokenCache) GetToken(ctx context.Context) (string, error) {
tc.mu.Lock()
defer tc.mu.Unlock()
if time.Until(tc.expiresAt) > 0 {
return tc.token, nil
}
token, err := tc.refreshFunc()
if err != nil {
return "", fmt.Errorf("token refresh failed: %w", err)
}
tc.token = token
tc.expiresAt = time.Now().Add(time.Duration(55) * time.Minute)
return tc.token, nil
}
func fetchOAuthToken(cfg OAuthConfig) (string, error) {
payload := map[string]interface{}{
"grant_type": cfg.GrantType,
"client_id": cfg.ClientID,
"client_secret": cfg.ClientSecret,
"scope": "logs:read replay:execute analytics:read webhooks:notify",
}
body, err := json.Marshal(payload)
if err != nil {
return "", fmt.Errorf("marshal token payload: %w", err)
}
req, err := http.NewRequest("POST", cfg.BaseURL+"/oauth/token", bytes.NewBuffer(body))
if err != nil {
return "", fmt.Errorf("create token 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 token request: %w", err)
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
return "", fmt.Errorf("oauth error: status %d", resp.StatusCode)
}
var tokenResp TokenResponse
if err := json.NewDecoder(resp.Body).Decode(&tokenResp); err != nil {
return "", fmt.Errorf("decode token response: %w", err)
}
return tokenResp.AccessToken, nil
}
The OAuth flow requires POST /oauth/token with grant_type=client_credentials. The token cache ensures concurrent goroutines do not trigger duplicate refresh calls. The cache expiry is set to 55 minutes to account for network latency and server clock drift.
Implementation
Step 1: Fetch Historical Logs with Atomic GET and Format Verification
Cognigy stores conversation logs as immutable event streams. You must retrieve logs using atomic GET operations to prevent partial reads during scaling events. The endpoint supports pagination and returns a log matrix containing timestamps, intents, slots, and branch paths.
type LogEntry struct {
Timestamp int64 `json:"timestamp"`
Intent string `json:"intent"`
Slot string `json:"slot"`
Value string `json:"value"`
Branch string `json:"branch"`
Action string `json:"action"`
}
type LogResponse struct {
Results []LogEntry `json:"results"`
HasMore bool `json:"hasMore"`
Cursor string `json:"cursor,omitempty"`
}
func fetchConversationLogs(ctx context.Context, baseURL, conversationID string, tokenCache *TokenCache) ([]LogEntry, error) {
var allLogs []LogEntry
cursor := ""
page := 1
for {
url := fmt.Sprintf("%s/api/v2/logs?conversationId=%s&format=matrix&cursor=%s", baseURL, conversationID, cursor)
token, err := tokenCache.GetToken(ctx)
if err != nil {
return nil, err
}
req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
if err != nil {
return nil, fmt.Errorf("create log request: %w", err)
}
req.Header.Set("Authorization", "Bearer "+token)
req.Header.Set("Accept", "application/json")
client := &http.Client{Timeout: 30 * time.Second}
resp, err := client.Do(req)
if err != nil {
return nil, fmt.Errorf("execute log request: %w", err)
}
defer resp.Body.Close()
if resp.StatusCode == http.StatusUnauthorized {
tokenCache.mu.Lock()
tokenCache.token = ""
tokenCache.expiresAt = time.Time{}
tokenCache.mu.Unlock()
return fetchConversationLogs(ctx, baseURL, conversationID, tokenCache)
}
var logResp LogResponse
if err := json.NewDecoder(resp.Body).Decode(&logResp); err != nil {
return nil, fmt.Errorf("decode log response: %w", err)
}
if len(logResp.Results) == 0 && logResp.Cursor == "" {
break
}
allLogs = append(allLogs, logResp.Results...)
cursor = logResp.Cursor
page++
if !logResp.HasMore || page > 50 {
break
}
}
return allLogs, nil
}
The GET /api/v2/logs endpoint requires the logs:read scope. Pagination uses a cursor-based model. The function enforces a maximum of 50 pages to prevent runaway memory allocation. Format verification occurs at the JSON decoding stage; malformed matrices will trigger a decode error that propagates to the caller.
Step 2: Construct Replay Payloads with Log Matrix and Simulation Directive
Replay payloads must map historical logs into a simulation matrix while injecting a directive that controls execution speed, state reset behavior, and branch override rules.
type SimulationDirective struct {
Mode string `json:"mode"`
SpeedFactor float64 `json:"speedFactor"`
ResetState bool `json:"resetState"`
OverrideBranch bool `json:"overrideBranch"`
}
type ReplayPayload struct {
ConversationID string `json:"conversationId"`
LogMatrix []LogEntry `json:"logMatrix"`
SimulationDirective SimulationDirective `json:"simulationDirective"`
RequestedAt int64 `json:"requestedAt"`
}
func buildReplayPayload(logs []LogEntry, directive SimulationDirective) ReplayPayload {
return ReplayPayload{
ConversationID: "replay-" + fmt.Sprint(time.Now().UnixNano()),
LogMatrix: logs,
SimulationDirective: directive,
RequestedAt: time.Now().UnixMilli(),
}
}
The payload structure aligns with Cognigy’s replay engine expectations. The simulationDirective controls how the analytics engine processes the log matrix. Setting resetState to true clears intermediate dialog state before execution. The speedFactor adjusts internal timers to simulate real-time pacing or accelerated playback.
Step 3: Validate Replay Schemas Against Analytics Constraints
Before execution, you must validate the payload against tenant-specific analytics constraints. This prevents replay failures caused by duration limits, unsupported branch paths, or timestamp drift.
type AnalyticsConstraints struct {
MaxReplayDurationMs int64 `json:"maxReplayDurationMs"`
AllowedBranches []string `json:"allowedBranches"`
TimestampDriftToleranceMs int64 `json:"timestampDriftToleranceMs"`
}
func fetchAnalyticsConstraints(ctx context.Context, baseURL string, tokenCache *TokenCache) (AnalyticsConstraints, error) {
token, err := tokenCache.GetToken(ctx)
if err != nil {
return AnalyticsConstraints{}, err
}
req, err := http.NewRequestWithContext(ctx, "GET", baseURL+"/api/v2/analytics/constraints", nil)
if err != nil {
return AnalyticsConstraints{}, err
}
req.Header.Set("Authorization", "Bearer "+token)
client := &http.Client{Timeout: 10 * time.Second}
resp, err := client.Do(req)
if err != nil {
return AnalyticsConstraints{}, err
}
defer resp.Body.Close()
var constraints AnalyticsConstraints
if err := json.NewDecoder(resp.Body).Decode(&constraints); err != nil {
return AnalyticsConstraints{}, fmt.Errorf("decode constraints: %w", err)
}
return constraints, nil
}
func validateReplayPayload(payload ReplayPayload, constraints AnalyticsConstraints) error {
if len(payload.LogMatrix) == 0 {
return fmt.Errorf("log matrix is empty")
}
startTime := payload.LogMatrix[0].Timestamp
endTime := payload.LogMatrix[len(payload.LogMatrix)-1].Timestamp
duration := endTime - startTime
if duration > constraints.MaxReplayDurationMs {
return fmt.Errorf("replay duration %dms exceeds maximum %dms", duration, constraints.MaxReplayDurationMs)
}
allowedBranchMap := make(map[string]bool)
for _, branch := range constraints.AllowedBranches {
allowedBranchMap[branch] = true
}
for i, entry := range payload.LogMatrix {
if i > 0 {
drift := entry.Timestamp - payload.LogMatrix[i-1].Timestamp
if drift < 0 || drift > constraints.TimestampDriftToleranceMs {
return fmt.Errorf("timestamp drift violation at index %d: %dms", i, drift)
}
}
if !allowedBranchMap[entry.Branch] {
return fmt.Errorf("branch path %s is not allowed by analytics constraints", entry.Branch)
}
}
return nil
}
The GET /api/v2/analytics/constraints endpoint requires the analytics:read scope. Validation enforces three rules: total duration limits, chronological timestamp alignment, and branch path allowlisting. The drift check ensures logs were not reordered during extraction.
Step 4: Execute Replay with State Reset and Branch Verification
Execution uses an atomic POST operation. The engine applies the simulation directive, processes the log matrix, and returns execution metrics. You must handle 429 rate limits with exponential backoff.
type ReplayResult struct {
ExecutionID string `json:"executionId"`
Status string `json:"status"`
DurationMs int64 `json:"durationMs"`
StepsProcessed int `json:"stepsProcessed"`
BranchPath string `json:"branchPath"`
Timestamp int64 `json:"timestamp"`
}
func retryOnRateLimit(ctx context.Context, fn func() (*http.Response, error)) (*http.Response, error) {
maxRetries := 4
backoff := 1 * time.Second
for attempt := 0; attempt < maxRetries; attempt++ {
resp, err := fn()
if err != nil {
return nil, err
}
if resp.StatusCode == http.StatusTooManyRequests {
resp.Body.Close()
select {
case <-time.After(backoff):
backoff *= 2
case <-ctx.Done():
return nil, ctx.Err()
}
continue
}
return resp, nil
}
return nil, fmt.Errorf("max retries exceeded for 429 rate limit")
}
func executeReplay(ctx context.Context, baseURL string, payload ReplayPayload, tokenCache *TokenCache) (ReplayResult, error) {
body, err := json.Marshal(payload)
if err != nil {
return ReplayResult{}, fmt.Errorf("marshal replay payload: %w", err)
}
var result ReplayResult
resp, err := retryOnRateLimit(ctx, func() (*http.Response, error) {
token, tokErr := tokenCache.GetToken(ctx)
if tokErr != nil {
return nil, tokErr
}
req, reqErr := http.NewRequestWithContext(ctx, "POST", baseURL+"/api/v2/replay/execute", bytes.NewBuffer(body))
if reqErr != nil {
return nil, reqErr
}
req.Header.Set("Authorization", "Bearer "+token)
req.Header.Set("Content-Type", "application/json")
req.Header.Set("Accept", "application/json")
client := &http.Client{Timeout: 60 * time.Second}
return client.Do(req)
})
if err != nil {
return ReplayResult{}, fmt.Errorf("execute replay request: %w", err)
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusCreated {
return ReplayResult{}, fmt.Errorf("replay execution failed: status %d", resp.StatusCode)
}
if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
return ReplayResult{}, fmt.Errorf("decode replay result: %w", err)
}
return result, nil
}
The POST /api/v2/replay/execute endpoint requires the replay:execute scope. The retry wrapper handles 429 responses with exponential backoff. The execution timeout is set to 60 seconds to accommodate longer log matrices. State reset triggers are evaluated server-side based on the resetState directive flag.
Step 5: Synchronize Events and Track Latency
Replay results must synchronize with external test harnesses via webhooks. You also need to track latency, success rates, and generate audit logs for governance.
type WebhookPayload struct {
ExecutionID string `json:"executionId"`
Status string `json:"status"`
LatencyMs int64 `json:"latencyMs"`
SuccessRate float64 `json:"successRate"`
Timestamp int64 `json:"timestamp"`
}
type ReplayMetrics struct {
mu sync.Mutex
totalRuns int
successful int
totalLatency int64
}
func (m *ReplayMetrics) RecordRun(latencyMs int64, success bool) {
m.mu.Lock()
defer m.mu.Unlock()
m.totalRuns++
m.totalLatency += latencyMs
if success {
m.successful++
}
}
func (m *ReplayMetrics) GetSuccessRate() float64 {
m.mu.Lock()
defer m.mu.Unlock()
if m.totalRuns == 0 {
return 0.0
}
return float64(m.successful) / float64(m.totalRuns)
}
func sendWebhookSync(ctx context.Context, webhookURL string, payload WebhookPayload) error {
body, err := json.Marshal(payload)
if err != nil {
return fmt.Errorf("marshal webhook payload: %w", err)
}
req, err := http.NewRequestWithContext(ctx, "POST", webhookURL, bytes.NewBuffer(body))
if err != nil {
return fmt.Errorf("create webhook 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 webhook request: %w", err)
}
defer resp.Body.Close()
if resp.StatusCode < 200 || resp.StatusCode >= 300 {
return fmt.Errorf("webhook sync failed: status %d", resp.StatusCode)
}
return nil
}
The webhook payload contains execution metrics and success rates. The metrics struct uses mutex protection for concurrent recording. Latency tracking captures the delta between payload submission and result receipt. Audit logging occurs at each pipeline stage via structured log entries.
Complete Working Example
package main
import (
"context"
"encoding/json"
"fmt"
"log/slog"
"os"
"time"
)
func main() {
ctx := context.Background()
baseURL := "https://api.cognigy.com"
webhookURL := "https://test-harness.example.com/webhooks/replay"
cfg := OAuthConfig{
BaseURL: baseURL,
ClientID: os.Getenv("COGNIGY_CLIENT_ID"),
ClientSecret: os.Getenv("COGNIGY_CLIENT_SECRET"),
GrantType: "client_credentials",
}
tokenCache := NewTokenCache(func() (string, error) {
return fetchOAuthToken(cfg)
})
conversationID := os.Getenv("COGNIGY_CONVERSATION_ID")
if conversationID == "" {
slog.Error("COGNIGY_CONVERSATION_ID environment variable not set")
os.Exit(1)
}
metrics := &ReplayMetrics{}
logger := slog.New(slog.NewJSONHandler(os.Stdout, nil))
logger.Info("starting replay engine", "conversationId", conversationID)
logs, err := fetchConversationLogs(ctx, baseURL, conversationID, tokenCache)
if err != nil {
logger.Error("failed to fetch logs", "error", err)
os.Exit(1)
}
directive := SimulationDirective{
Mode: "simulation",
SpeedFactor: 1.0,
ResetState: true,
OverrideBranch: false,
}
payload := buildReplayPayload(logs, directive)
constraints, err := fetchAnalyticsConstraints(ctx, baseURL, tokenCache)
if err != nil {
logger.Error("failed to fetch constraints", "error", err)
os.Exit(1)
}
if err := validateReplayPayload(payload, constraints); err != nil {
logger.Error("validation failed", "error", err)
os.Exit(1)
}
startTime := time.Now()
result, err := executeReplay(ctx, baseURL, payload, tokenCache)
latency := time.Since(startTime).Milliseconds()
success := err == nil && result.Status == "completed"
metrics.RecordRun(latency, success)
webhookPayload := WebhookPayload{
ExecutionID: result.ExecutionID,
Status: result.Status,
LatencyMs: latency,
SuccessRate: metrics.GetSuccessRate(),
Timestamp: time.Now().UnixMilli(),
}
if err := sendWebhookSync(ctx, webhookURL, webhookPayload); err != nil {
logger.Warn("webhook sync failed", "error", err)
}
auditLog := map[string]interface{}{
"event": "replay_executed",
"executionId": result.ExecutionID,
"status": result.Status,
"latencyMs": latency,
"success": success,
"timestamp": time.Now().UnixMilli(),
}
auditJSON, _ := json.Marshal(auditLog)
logger.Info("audit log generated", "payload", string(auditJSON))
fmt.Printf("Replay completed: status=%s, duration=%dms, latency=%dms\n", result.Status, result.DurationMs, latency)
}
This script initializes the OAuth cache, fetches logs, validates against constraints, executes the replay, synchronizes with the test harness, records metrics, and generates an audit log. Replace environment variables with your tenant credentials before execution.
Common Errors & Debugging
Error: 401 Unauthorized
- Cause: Expired or invalid OAuth token. The client credentials grant may have been revoked or the token cache returned a stale value.
- Fix: Force cache invalidation by setting
expiresAtto a past time. Verifyclient_idandclient_secretmatch the registered OAuth application. - Code Fix: The
TokenCacheimplementation automatically retries with a fresh token whenStatusUnauthorizedis detected.
Error: 403 Forbidden
- Cause: Missing OAuth scope. The replay engine requires
replay:executeandlogs:read. Analytics validation requiresanalytics:read. - Fix: Update the OAuth application configuration in the Cognigy admin portal. Add the missing scopes to the
scopeparameter in the token request. - Code Fix: Verify the
fetchOAuthTokenfunction includes all required scopes in the grant payload.
Error: 429 Too Many Requests
- Cause: Rate limit exceeded on the replay execution endpoint. Cognigy enforces per-tenant and per-endpoint throttling.
- Fix: Implement exponential backoff. The
retryOnRateLimitwrapper handles this automatically. Reduce concurrent replay executions if you scale the pipeline. - Code Fix: The retry function waits 1s, 2s, 4s, 8s before retrying. Adjust
maxRetriesif your tenant allows higher throughput.
Error: 400 Bad Request (Schema Validation)
- Cause: Replay payload violates analytics constraints. Common triggers include exceeding
maxReplayDurationMs, timestamp drift, or disallowed branch paths. - Fix: Review the
validateReplayPayloadoutput. Trim logs to fit duration limits. Correct timestamp ordering. Verify branch paths against the allowed list. - Code Fix: The validation function returns specific error messages indicating the exact index or constraint violated.
Error: 500 Internal Server Error
- Cause: Server-side processing failure during simulation execution. Usually caused by malformed log matrices or unsupported directive configurations.
- Fix: Validate JSON structure against Cognigy’s schema. Ensure
simulationDirectivematches supported modes. Contact Cognigy support if the error persists with valid payloads. - Code Fix: Wrap execution in a retry loop with circuit breaker logic if 5xx errors occur repeatedly.