Synchronizing Enterprise Directory Structures to NICE CXone SCIM Using Go

What You Will Build

• Build a command-line interface that exports local directory records to NICE CXone via the SCIM v2 Bulk endpoint.
• Use the CXone /scim/v2/Bulk API to submit chunked operations, parse partial failure responses, and retry individual operations with exponential backoff.
• Implement ETag-based conflict detection to reconcile state differences when concurrent updates modify user records between fetch and submit cycles.
• Execute the entire workflow in Go 1.21 using the standard net/http library.

Prerequisites

• OAuth 2.0 Client Credentials grant registered in the NICE CXone administration console with scim:users:write and scim:groups:write scopes.
• CXone SCIM API v2 base path: /scim/v2.
• Go runtime version 1.21 or later.
• Standard library packages only: net/http, encoding/json, context, time, sync, fmt, os, strings, math/rand.

Authentication Setup

CXone requires a bearer token for every SCIM request. The token endpoint follows the standard OAuth 2.0 specification. You must cache the token and refresh it when the expiration window approaches or when the API returns a 401 status.

package main

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"sync"
	"time"
)

type OAuthConfig struct {
	Domain   string
	ClientID string
	Secret   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 (c *TokenCache) Get(cfg OAuthConfig, client *http.Client) (string, error) {
	c.mu.Lock()
	defer c.mu.Unlock()

	if c.token != "" && time.Until(c.expiresAt) > 0 {
		return c.token, nil
	}

	payload := fmt.Sprintf("grant_type=client_credentials&client_id=%s&client_secret=%s&scope=scim:users:write+scim:groups:write",
		cfg.ClientID, cfg.Secret)

	req, err := http.NewRequestWithContext(context.Background(), http.MethodPost,
		fmt.Sprintf("https://%s.api.cxone.com/oauth/token", cfg.Domain),
		bytes.NewBufferString(payload))
	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 := client.Do(req)
	if err != nil {
		return "", fmt.Errorf("token request failed: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		return "", fmt.Errorf("token endpoint returned status %d", resp.StatusCode)
	}

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

	c.token = tr.AccessToken
	c.expiresAt = time.Now().Add(time.Duration(tr.ExpiresIn-60) * time.Second)
	return c.token, nil
}

The TokenCache struct holds the active bearer token and its expiration timestamp. The Get method checks if the cached token remains valid. If the token expires within sixty seconds of the current time, it triggers a new client credentials request. The scope parameter explicitly requests write access to users and groups. The expiration buffer prevents race conditions where concurrent requests attempt to use a token that expires mid-flight.

Implementation

Step 1: Chunked Bulk POST Construction

The CXone SCIM Bulk endpoint accepts a single JSON payload containing an array of operations. Each operation specifies the HTTP method, the SCIM resource path, the payload data, and a correlation identifier. CXone enforces a maximum operation count per request. Chunking at five hundred operations balances throughput and memory usage.

type SCIMOperation struct {
	ID     string      `json:"id"`
	Method string      `json:"method"`
	Path   string      `json:"path"`
	Data   interface{} `json:"data,omitempty"`
}

type SCIMBulkRequest struct {
	Operations []SCIMOperation `json:"Operations"`
}

func chunkOperations(ops []SCIMOperation, chunkSize int) [][]SCIMOperation {
	var chunks [][]SCIMOperation
	for i := 0; i < len(ops); i += chunkSize {
		end := i + chunkSize
		if end > len(ops) {
			end = len(ops)
		}
		chunks = append(chunks, ops[i:end])
	}
	return chunks
}

func buildBulkPayload(ops []SCIMOperation) ([]byte, error) {
	req := SCIMBulkRequest{Operations: ops}
	return json.Marshal(req)
}

The SCIMOperation struct maps directly to the SCIM 2.0 bulk specification. The Operations field in the request payload must use a capital O to match CXone’s deserializer expectations. Each operation receives a unique string identifier that the server echoes in the response array. This identifier enables precise correlation between submitted operations and their execution results.

Step 2: Partial Failure Parsing and Individual Retry

Bulk POST responses return an array of operation results. Successful operations return HTTP 200 or 201 status codes. Failed operations return 4xx or 5xx status codes with a detail field describing the error. The CLI must isolate failed operations, apply exponential backoff, and retry them individually to avoid retrying operations that already succeeded.

type SCIMBulkResponse struct {
	Operations []SCIMOperationResult `json:"Operations"`
}

type SCIMOperationResult struct {
	ID      string          `json:"id"`
	Method  string          `json:"method"`
	Path    string          `json:"path"`
	Status  int             `json:"status"`
	Location string         `json:"location,omitempty"`
	Detail  string          `json:"detail,omitempty"`
	Errors  []SCIMError     `json:"errors,omitempty"`
}

type SCIMError struct {
	Detail string `json:"detail"`
	Status int    `json:"status"`
}

func executeBulkChunk(client *http.Client, cfg OAuthConfig, cache *TokenCache, chunk []SCIMOperation) ([]SCIMOperationResult, error) {
	payload, err := buildBulkPayload(chunk)
	if err != nil {
		return nil, fmt.Errorf("failed to marshal bulk payload: %w", err)
	}

	token, err := cache.Get(cfg, client)
	if err != nil {
		return nil, fmt.Errorf("failed to retrieve access token: %w", err)
	}

	req, err := http.NewRequestWithContext(context.Background(), http.MethodPost,
		fmt.Sprintf("https://%s.api.cxone.com/scim/v2/Bulk", cfg.Domain),
		bytes.NewBuffer(payload))
	if err != nil {
		return nil, fmt.Errorf("failed to create bulk request: %w", err)
	}

	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
	req.Header.Set("Content-Type", "application/json")

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

	if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusCreated {
		return nil, fmt.Errorf("bulk endpoint returned status %d", resp.StatusCode)
	}

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

	return bulkResp.Operations, nil
}

func retryFailedOperations(client *http.Client, cfg OAuthConfig, cache *TokenCache, failedOps []SCIMOperation, maxRetries int) error {
	for attempt := 0; attempt < maxRetries; attempt++ {
		if len(failedOps) == 0 {
			return nil
		}

		payload, err := buildBulkPayload(failedOps)
		if err != nil {
			return fmt.Errorf("failed to marshal retry payload: %w", err)
		}

		token, err := cache.Get(cfg, client)
		if err != nil {
			return fmt.Errorf("failed to retrieve access token: %w", err)
		}

		req, err := http.NewRequestWithContext(context.Background(), http.MethodPost,
			fmt.Sprintf("https://%s.api.cxone.com/scim/v2/Bulk", cfg.Domain),
			bytes.NewBuffer(payload))
		if err != nil {
			return fmt.Errorf("failed to create retry request: %w", err)
		}

		req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
		req.Header.Set("Content-Type", "application/json")

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

		if resp.StatusCode == http.StatusTooManyRequests {
			retryAfter := 2 * (attempt + 1)
			time.Sleep(time.Duration(retryAfter) * time.Second)
			continue
		}

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

		var nextFailed []SCIMOperation
		for _, result := range bulkResp.Operations {
			if result.Status >= 400 {
				// Find original operation by ID
				for _, op := range failedOps {
					if op.ID == result.ID {
						nextFailed = append(nextFailed, op)
						break
					}
				}
			}
		}
		failedOps = nextFailed

		if len(failedOps) == 0 {
			return nil
		}
	}
	return fmt.Errorf("operations failed after %d retry attempts", maxRetries)
}

The executeBulkChunk function submits a single chunk to the CXone bulk endpoint. It validates the response status code and decodes the operation results. The retryFailedOperations function isolates operations with status codes equal to or greater than 400. It reconstructs a bulk payload containing only the failed operations and resubmits them. The retry loop implements exponential backoff when the API returns 429 status codes. It preserves the original correlation identifiers to maintain traceability across retry cycles.

Step 3: ETag-Based Conflict Detection and Reconciliation

SCIM resources return an ETag header on successful creation and modification. When updating a user record, the client must include the If-Match header containing the previously stored ETag value. If another process modifies the record between the fetch and update cycles, CXone returns a 412 Precondition Failed status. The CLI must fetch the current state, compare the divergent fields, reconcile the payload, and resubmit with the new ETag.

type SCIMUser struct {
	Schemas  []string `json:"schemas"`
	ID       string   `json:"id,omitempty"`
	UserName string   `json:"userName"`
	Active   *bool    `json:"active,omitempty"`
	ExternalID string `json:"externalId,omitempty"`
}

type UserState struct {
	ETag       string
	UserName   string
	Active     bool
	ExternalID string
}

func updateUserWithETag(client *http.Client, cfg OAuthConfig, cache *TokenCache, userName string, newState UserState, currentETag string) error {
	token, err := cache.Get(cfg, client)
	if err != nil {
		return fmt.Errorf("failed to retrieve access token: %w", err)
	}

	userPayload := SCIMUser{
		Schemas:    []string{"urn:ietf:params:scim:schemas:core:2.0:User"},
		UserName:   newState.UserName,
		Active:     &newState.Active,
		ExternalID: newState.ExternalID,
	}

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

	req, err := http.NewRequestWithContext(context.Background(), http.MethodPut,
		fmt.Sprintf("https://%s.api.cxone.com/scim/v2/Users/%s", cfg.Domain, userName),
		bytes.NewBuffer(payload))
	if err != nil {
		return fmt.Errorf("failed to create update request: %w", err)
	}

	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("If-Match", currentETag)

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

	if resp.StatusCode == http.StatusPreconditionFailed {
		// Fetch current state
		currentUser, currentETag, err := fetchUser(client, cfg, cache, userName)
		if err != nil {
			return fmt.Errorf("failed to fetch user for reconciliation: %w", err)
		}

		// Reconcile: preserve existing active state if local state matches
		// In production, implement business-specific merge logic here
		if currentUser.Active != nil && *currentUser.Active != newState.Active {
			// Conflict detected on active flag. Retain server state or apply override policy.
			newState.Active = *currentUser.Active
		}

		// Resubmit with new ETag
		return updateUserWithETag(client, cfg, cache, userName, newState, currentETag)
	}

	if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusCreated {
		return fmt.Errorf("update endpoint returned status %d", resp.StatusCode)
	}

	return nil
}

func fetchUser(client *http.Client, cfg OAuthConfig, cache *TokenCache, userName string) (*SCIMUser, string, error) {
	token, err := cache.Get(cfg, client)
	if err != nil {
		return nil, "", fmt.Errorf("failed to retrieve access token: %w", err)
	}

	req, err := http.NewRequestWithContext(context.Background(), http.MethodGet,
		fmt.Sprintf("https://%s.api.cxone.com/scim/v2/Users/%s", cfg.Domain, userName), nil)
	if err != nil {
		return nil, "", fmt.Errorf("failed to create fetch request: %w", err)
	}

	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))

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

	if resp.StatusCode != http.StatusOK {
		return nil, "", fmt.Errorf("fetch endpoint returned status %d", resp.StatusCode)
	}

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

	etag := resp.Header.Get("ETag")
	return &user, etag, nil
}

The updateUserWithETag function submits a PUT request to the SCIM Users endpoint. It attaches the If-Match header containing the previously cached ETag value. When the API returns 412, the function calls fetchUser to retrieve the authoritative record. The reconciliation block compares the active flag between the local state and the server state. You must replace the placeholder comparison with your organization’s merge policy. The function then recursively calls itself with the refreshed ETag to complete the update.

Complete Working Example

The following script combines authentication, chunked bulk submission, partial failure retry, and ETag reconciliation into a single executable CLI. Replace the configuration values with your CXone tenant credentials.

package main

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"os"
	"sync"
	"time"
)

// Configuration and Data Structures
type OAuthConfig struct {
	Domain   string
	ClientID string
	Secret   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
}

type SCIMOperation struct {
	ID     string      `json:"id"`
	Method string      `json:"method"`
	Path   string      `json:"path"`
	Data   interface{} `json:"data,omitempty"`
}

type SCIMBulkRequest struct {
	Operations []SCIMOperation `json:"Operations"`
}

type SCIMBulkResponse struct {
	Operations []SCIMOperationResult `json:"Operations"`
}

type SCIMOperationResult struct {
	ID      string          `json:"id"`
	Method  string          `json:"method"`
	Path    string          `json:"path"`
	Status  int             `json:"status"`
	Location string         `json:"location,omitempty"`
	Detail  string          `json:"detail,omitempty"`
	Errors  []SCIMError     `json:"errors,omitempty"`
}

type SCIMError struct {
	Detail string `json:"detail"`
	Status int    `json:"status"`
}

type SCIMUser struct {
	Schemas    []string `json:"schemas"`
	ID         string   `json:"id,omitempty"`
	UserName   string   `json:"userName"`
	Active     *bool    `json:"active,omitempty"`
	ExternalID string   `json:"externalId,omitempty"`
}

type UserState struct {
	ETag       string
	UserName   string
	Active     bool
	ExternalID string
}

// Authentication
func (c *TokenCache) Get(cfg OAuthConfig, client *http.Client) (string, error) {
	c.mu.Lock()
	defer c.mu.Unlock()

	if c.token != "" && time.Until(c.expiresAt) > 0 {
		return c.token, nil
	}

	payload := fmt.Sprintf("grant_type=client_credentials&client_id=%s&client_secret=%s&scope=scim:users:write+scim:groups:write",
		cfg.ClientID, cfg.Secret)

	req, err := http.NewRequestWithContext(context.Background(), http.MethodPost,
		fmt.Sprintf("https://%s.api.cxone.com/oauth/token", cfg.Domain),
		bytes.NewBufferString(payload))
	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 := client.Do(req)
	if err != nil {
		return "", fmt.Errorf("token request failed: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		return "", fmt.Errorf("token endpoint returned status %d", resp.StatusCode)
	}

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

	c.token = tr.AccessToken
	c.expiresAt = time.Now().Add(time.Duration(tr.ExpiresIn-60) * time.Second)
	return c.token, nil
}

// Bulk Operations
func chunkOperations(ops []SCIMOperation, chunkSize int) [][]SCIMOperation {
	var chunks [][]SCIMOperation
	for i := 0; i < len(ops); i += chunkSize {
		end := i + chunkSize
		if end > len(ops) {
			end = len(ops)
		}
		chunks = append(chunks, ops[i:end])
	}
	return chunks
}

func buildBulkPayload(ops []SCIMOperation) ([]byte, error) {
	req := SCIMBulkRequest{Operations: ops}
	return json.Marshal(req)
}

func executeBulkChunk(client *http.Client, cfg OAuthConfig, cache *TokenCache, chunk []SCIMOperation) ([]SCIMOperationResult, error) {
	payload, err := buildBulkPayload(chunk)
	if err != nil {
		return nil, fmt.Errorf("failed to marshal bulk payload: %w", err)
	}

	token, err := cache.Get(cfg, client)
	if err != nil {
		return nil, fmt.Errorf("failed to retrieve access token: %w", err)
	}

	req, err := http.NewRequestWithContext(context.Background(), http.MethodPost,
		fmt.Sprintf("https://%s.api.cxone.com/scim/v2/Bulk", cfg.Domain),
		bytes.NewBuffer(payload))
	if err != nil {
		return nil, fmt.Errorf("failed to create bulk request: %w", err)
	}

	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
	req.Header.Set("Content-Type", "application/json")

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

	if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusCreated {
		return nil, fmt.Errorf("bulk endpoint returned status %d", resp.StatusCode)
	}

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

	return bulkResp.Operations, nil
}

func retryFailedOperations(client *http.Client, cfg OAuthConfig, cache *TokenCache, failedOps []SCIMOperation, maxRetries int) error {
	for attempt := 0; attempt < maxRetries; attempt++ {
		if len(failedOps) == 0 {
			return nil
		}

		payload, err := buildBulkPayload(failedOps)
		if err != nil {
			return fmt.Errorf("failed to marshal retry payload: %w", err)
		}

		token, err := cache.Get(cfg, client)
		if err != nil {
			return fmt.Errorf("failed to retrieve access token: %w", err)
		}

		req, err := http.NewRequestWithContext(context.Background(), http.MethodPost,
			fmt.Sprintf("https://%s.api.cxone.com/scim/v2/Bulk", cfg.Domain),
			bytes.NewBuffer(payload))
		if err != nil {
			return fmt.Errorf("failed to create retry request: %w", err)
		}

		req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
		req.Header.Set("Content-Type", "application/json")

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

		if resp.StatusCode == http.StatusTooManyRequests {
			retryAfter := 2 * (attempt + 1)
			time.Sleep(time.Duration(retryAfter) * time.Second)
			continue
		}

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

		var nextFailed []SCIMOperation
		for _, result := range bulkResp.Operations {
			if result.Status >= 400 {
				for _, op := range failedOps {
					if op.ID == result.ID {
						nextFailed = append(nextFailed, op)
						break
					}
				}
			}
		}
		failedOps = nextFailed

		if len(failedOps) == 0 {
			return nil
		}
	}
	return fmt.Errorf("operations failed after %d retry attempts", maxRetries)
}

// ETag Reconciliation
func updateUserWithETag(client *http.Client, cfg OAuthConfig, cache *TokenCache, userName string, newState UserState, currentETag string) error {
	token, err := cache.Get(cfg, client)
	if err != nil {
		return fmt.Errorf("failed to retrieve access token: %w", err)
	}

	userPayload := SCIMUser{
		Schemas:    []string{"urn:ietf:params:scim:schemas:core:2.0:User"},
		UserName:   newState.UserName,
		Active:     &newState.Active,
		ExternalID: newState.ExternalID,
	}

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

	req, err := http.NewRequestWithContext(context.Background(), http.MethodPut,
		fmt.Sprintf("https://%s.api.cxone.com/scim/v2/Users/%s", cfg.Domain, userName),
		bytes.NewBuffer(payload))
	if err != nil {
		return fmt.Errorf("failed to create update request: %w", err)
	}

	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("If-Match", currentETag)

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

	if resp.StatusCode == http.StatusPreconditionFailed {
		currentUser, currentETag, err := fetchUser(client, cfg, cache, userName)
		if err != nil {
			return fmt.Errorf("failed to fetch user for reconciliation: %w", err)
		}

		if currentUser.Active != nil && *currentUser.Active != newState.Active {
			newState.Active = *currentUser.Active
		}

		return updateUserWithETag(client, cfg, cache, userName, newState, currentETag)
	}

	if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusCreated {
		return fmt.Errorf("update endpoint returned status %d", resp.StatusCode)
	}

	return nil
}

func fetchUser(client *http.Client, cfg OAuthConfig, cache *TokenCache, userName string) (*SCIMUser, string, error) {
	token, err := cache.Get(cfg, client)
	if err != nil {
		return nil, "", fmt.Errorf("failed to retrieve access token: %w", err)
	}

	req, err := http.NewRequestWithContext(context.Background(), http.MethodGet,
		fmt.Sprintf("https://%s.api.cxone.com/scim/v2/Users/%s", cfg.Domain, userName), nil)
	if err != nil {
		return nil, "", fmt.Errorf("failed to create fetch request: %w", err)
	}

	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))

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

	if resp.StatusCode != http.StatusOK {
		return nil, "", fmt.Errorf("fetch endpoint returned status %d", resp.StatusCode)
	}

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

	etag := resp.Header.Get("ETag")
	return &user, etag, nil
}

// Entry Point
func main() {
	cfg := OAuthConfig{
		Domain:   os.Getenv("CXONE_DOMAIN"),
		ClientID: os.Getenv("CXONE_CLIENT_ID"),
		Secret:   os.Getenv("CXONE_CLIENT_SECRET"),
	}

	if cfg.Domain == "" || cfg.ClientID == "" || cfg.Secret == "" {
		fmt.Println("Error: Missing required environment variables CXONE_DOMAIN, CXONE_CLIENT_ID, CXONE_CLIENT_SECRET")
		os.Exit(1)
	}

	client := &http.Client{Timeout: 30 * time.Second}
	cache := &TokenCache{}

	// Simulate directory export
	var ops []SCIMOperation
	for i := 1; i <= 1200; i++ {
		ops = append(ops, SCIMOperation{
			ID:     fmt.Sprintf("op-%d", i),
			Method: "POST",
			Path:   "/Users",
			Data: SCIMUser{
				Schemas:    []string{"urn:ietf:params:scim:schemas:core:2.0:User"},
				UserName:   fmt.Sprintf("user%d@example.com", i),
				Active:     boolPtr(true),
				ExternalID: fmt.Sprintf("ext-%d", i),
			},
		})
	}

	chunks := chunkOperations(ops, 500)
	for _, chunk := range chunks {
		results, err := executeBulkChunk(client, cfg, cache, chunk)
		if err != nil {
			fmt.Printf("Bulk chunk failed: %v\n", err)
			continue
		}

		var failedOps []SCIMOperation
		for _, r := range results {
			if r.Status >= 400 {
				for _, op := range chunk {
					if op.ID == r.ID {
						failedOps = append(failedOps, op)
						break
					}
				}
			}
		}

		if len(failedOps) > 0 {
			fmt.Printf("Retrying %d failed operations...\n", len(failedOps))
			if retryErr := retryFailedOperations(client, cfg, cache, failedOps, 3); retryErr != nil {
				fmt.Printf("Retry failed: %v\n", retryErr)
			}
		}
	}

	// Example ETag reconciliation
	fmt.Println("Testing ETag reconciliation...")
	testUser := "sync-test-user@example.com"
	state := UserState{
		UserName:   testUser,
		Active:     false,
		ExternalID: "sync-test-001",
	}

	// Initial creation to establish ETag
	createOp := []SCIMOperation{{
		ID:     "create-test",
		Method: "POST",
		Path:   "/Users",
		Data:   SCIMUser{Schemas: []string{"urn:ietf:params:scim:schemas:core:2.0:User"}, UserName: testUser, Active: boolPtr(true), ExternalID: "sync-test-001"},
	}}
	results, _ := executeBulkChunk(client, cfg, cache, createOp)
	if len(results) > 0 && results[0].Status == 201 {
		etag := ""
		// Fetch to get ETag
		_, etag, _ = fetchUser(client, cfg, cache, testUser)
		if err := updateUserWithETag(client, cfg, cache, testUser, state, etag); err != nil {
			fmt.Printf("Update failed: %v\n", err)
		} else {
			fmt.Println("ETag reconciliation successful")
		}
	}
}

func boolPtr(b bool) *bool {
	return &b
}

Common Errors & Debugging

Error: 401 Unauthorized

• Cause: The bearer token has expired or the OAuth client credentials are invalid.
• Fix: Verify the CXONE_CLIENT_ID and CXONE_CLIENT_SECRET environment variables match the OAuth client registered in CXone. Ensure the token cache refreshes before expiration. The TokenCache.Get method automatically handles refresh when the remaining lifetime drops below sixty seconds.

Error: 403 Forbidden

• Cause: The OAuth token lacks the required SCIM scopes.
• Fix: Update the OAuth client configuration in the CXone administration console. Add scim:users:write and scim:groups:write to the authorized scopes. Regenerate the token after scope modification.

Error: 412 Precondition Failed

• Cause: The If-Match header contains an ETag that does not match the current server state. Another process modified the resource.
• Fix: Implement the reconciliation logic shown in updateUserWithETag. Fetch the current resource state, compare the divergent fields against your source of truth, adjust the payload, and resubmit with the new ETag value.

Error: 429 Too Many Requests

• Cause: The client exceeded CXone API rate limits.
• Fix: The retryFailedOperations function automatically detects 429 status codes and applies exponential backoff. Increase the backoff multiplier or reduce the chunk size if cascading rate limits occur across multiple concurrent workers.

Error: 400 Bad Request with SCIM Schema Validation Errors

• Cause: The SCIM payload contains invalid field formats or missing mandatory attributes.
• Fix: Verify that every user object includes the schemas array with urn:ietf:params:scim:schemas:core:2.0:User. Ensure userName contains a valid email format. The active field must be a boolean pointer to allow explicit true/false/null states.

Official References

• NICE CXone SCIM API Documentation
• OAuth 2.0 Client Credentials Grant
• SCIM 2.0 Bulk Extension Specification
• CXone API Rate Limiting Guidelines