Decoupling NICE CXone Decision Nodes via Flow API with Go

What You Will Build

A production-ready Go utility that extracts decision nodes from monolithic NICE CXone flows by constructing decoupling payloads, validating graph constraints, applying atomic HTTP PATCH operations, and tracking decoupling metrics. This tutorial uses the NICE CXone Flow API (/api/v2/flow/flows/{flowId}) and the OAuth 2.0 Client Credentials flow. The implementation is written in Go 1.21+ using the standard library and encoding/json.

Prerequisites

• NICE CXone Developer Portal credentials (CLIENT_ID, CLIENT_SECRET, BASE_URL)
• OAuth scopes: flow:flows:read, flow:flows:write
• Go 1.21 or higher
• Dependencies: standard library only (net/http, encoding/json, context, time, sync, fmt, log, os, flag, math, strings)
• Target flow must contain at least one routing or decision node with multiple conditional branches

Authentication Setup

The NICE CXone API requires an OAuth 2.0 bearer token. The Client Credentials flow exchanges client secrets for an access token. Tokens expire after 30 minutes, so the implementation caches the token and refreshes it automatically when expiration approaches.

package main

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

type OAuthConfig struct {
	BaseURL       string
	ClientID      string
	ClientSecret  string
}

type TokenResponse struct {
	AccessToken string `json:"access_token"`
	ExpiresIn   int64  `json:"expires_in"`
	TokenType   string `json:"token_type"`
}

type TokenCache struct {
	mu        sync.Mutex
	token     *TokenResponse
	expiresAt time.Time
}

func NewTokenCache() *TokenCache {
	return &TokenCache{}
}

func (c *TokenCache) GetToken(ctx context.Context, cfg OAuthConfig) (string, error) {
	c.mu.Lock()
	defer c.mu.Unlock()

	if c.token != nil && time.Now().Before(c.expiresAt.Add(-time.Minute)) {
		return c.token.AccessToken, nil
	}

	payload := fmt.Sprintf("grant_type=client_credentials&client_id=%s&client_secret=%s", cfg.ClientID, cfg.ClientSecret)
	req, err := http.NewRequestWithContext(ctx, http.MethodPost, fmt.Sprintf("%s/oauth/token", cfg.BaseURL), bytes.NewBufferString(payload))
	if err != nil {
		return "", fmt.Errorf("creating token request: %w", err)
	}
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")

	client := &http.Client{Timeout: 10 * time.Second}
	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("oauth token error: %d %s", resp.StatusCode, resp.Status)
	}

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

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

Implementation

Step 1: Fetch Target Flow and Construct Flow Matrix

The NICE CXone Flow API returns a complete flow graph. You must parse the response into an adjacency structure (flow-matrix) to identify decision nodes, their conditional branches, and their fallback paths. This matrix enables safe isolation planning.

type FlowNode struct {
	ID          string      `json:"id"`
	Type        string      `json:"type"`
	Conditions  []Condition `json:"conditions,omitempty"`
	DefaultEdge string      `json:"defaultEdge,omitempty"`
}

type Condition struct {
	Expression string `json:"expression"`
	TargetID   string `json:"targetId"`
}

type FlowMatrix map[string]*FlowNode

func FetchFlow(ctx context.Context, baseURL, flowID, token string) (*FlowMatrix, error) {
	req, err := http.NewRequestWithContext(ctx, http.MethodGet, fmt.Sprintf("%s/api/v2/flow/flows/%s", baseURL, flowID), nil)
	if err != nil {
		return nil, fmt.Errorf("creating flow request: %w", err)
	}
	req.Header.Set("Authorization", "Bearer "+token)
	req.Header.Set("Accept", "application/json")

	client := &http.Client{Timeout: 15 * time.Second}
	resp, err := client.Do(req)
	if err != nil {
		return nil, fmt.Errorf("flow fetch failed: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("flow fetch error: %d", resp.StatusCode)
	}

	var rawFlow struct {
		Nodes []struct {
			ID         string        `json:"id"`
			Type       string        `json:"type"`
			Conditions []Condition   `json:"conditions,omitempty"`
			DefaultEdge string       `json:"defaultEdge,omitempty"`
		} `json:"nodes"`
	}

	if err := json.NewDecoder(resp.Body).Decode(&rawFlow); err != nil {
		return nil, fmt.Errorf("decoding flow: %w", err)
	}

	matrix := make(FlowMatrix)
	for _, n := range rawFlow.Nodes {
		matrix[n.ID] = &FlowNode{
			ID:          n.ID,
			Type:        n.Type,
			Conditions:  n.Conditions,
			DefaultEdge: n.DefaultEdge,
		}
	}
	return &matrix, nil
}

Step 2: Construct Isolate Directive and Validate Constraints

You must define the isolate directive payload that marks a decision node for decoupling. Before applying it, validate against flow-constraints (single entry point, valid node types) and maximum-branch-complexity limits. CXone enforces a hard limit of 500 nodes per flow and restricts branching depth. The validation pipeline rejects payloads that would exceed these thresholds or create invalid graphs.

type IsolateDirective struct {
	NodeRef             string      `json:"nodeRef"`
	TargetFlowID        string      `json:"targetFlowId"`
	ConditionalMapping  []Condition `json:"conditionalLogicMapping"`
	FallbackPath        string      `json:"fallbackPath"`
	IsolateTrigger      string      `json:"isolateTrigger"`
}

type DecouplingPayload struct {
	Op    string             `json:"op"`
	Path  string             `json:"path"`
	Value IsolateDirective   `json:"value"`
}

func ValidateIsolateDirective(directive IsolateDirective, matrix *FlowMatrix, maxBranchComplexity int) error {
	node, exists := (*matrix)[directive.NodeRef]
	if !exists {
		return fmt.Errorf("nodeRef %s not found in flow-matrix", directive.NodeRef)
	}

	if node.Type != "routing" && node.Type != "decision" {
		return fmt.Errorf("nodeRef %s is type %s, must be routing or decision", directive.NodeRef, node.Type)
	}

	branchCount := len(directive.ConditionalMapping)
	if branchCount > maxBranchComplexity {
		return fmt.Errorf("conditional branches %d exceed maximum-branch-complexity %d", branchCount, maxBranchComplexity)
	}

	if directive.FallbackPath == "" {
		return fmt.Errorf("fallbackPath is required for safe isolate iteration")
	}

	if _, exists := (*matrix)[directive.FallbackPath]; !exists {
		return fmt.Errorf("fallbackPath %s does not exist in flow-matrix", directive.FallbackPath)
	}

	return nil
}

Step 3: Generate Atomic JSON Patch and Apply with Retry Logic

NICE CXone supports atomic updates via PATCH /api/v2/flow/flows/{flowId} using the application/json-patch+json format. You must format the payload as a JSON Patch array. The implementation includes exponential backoff for 429 rate limits and verifies the response format.

type RetryConfig struct {
	MaxRetries int
	BaseDelay  time.Duration
}

func ApplyAtomicPatch(ctx context.Context, baseURL, flowID, token string, directive IsolateDirective, cfg RetryConfig) error {
	payload := []DecouplingPayload{
		{
			Op:    "add",
			Path:  fmt.Sprintf("/nodes/%s/isolateDirective", directive.NodeRef),
			Value: directive,
		},
	}

	jsonData, err := json.Marshal(payload)
	if err != nil {
		return fmt.Errorf("marshaling patch payload: %w", err)
	}

	var lastErr error
	for i := 0; i <= cfg.MaxRetries; i++ {
		req, err := http.NewRequestWithContext(ctx, http.MethodPatch, fmt.Sprintf("%s/api/v2/flow/flows/%s", baseURL, flowID), bytes.NewBuffer(jsonData))
		if err != nil {
			return fmt.Errorf("creating patch request: %w", err)
		}
		req.Header.Set("Authorization", "Bearer "+token)
		req.Header.Set("Content-Type", "application/json-patch+json")
		req.Header.Set("Accept", "application/json")

		client := &http.Client{Timeout: 20 * time.Second}
		resp, err := client.Do(req)
		if err != nil {
			lastErr = fmt.Errorf("patch request failed: %w", err)
			continue
		}
		defer resp.Body.Close()

		if resp.StatusCode == http.StatusTooManyRequests {
			lastErr = fmt.Errorf("rate limited (429)")
			time.Sleep(cfg.BaseDelay * time.Duration(math.Pow(2, float64(i))))
			continue
		}

		if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusAccepted {
			lastErr = fmt.Errorf("patch failed: %d", resp.StatusCode)
			continue
		}

		// Verify response format
		var result struct {
			Message string `json:"message"`
			Status  string `json:"status"`
		}
		if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
			lastErr = fmt.Errorf("decoding patch response: %w", err)
			continue
		}

		if result.Status != "success" {
			lastErr = fmt.Errorf("patch status not success: %s", result.Status)
			continue
		}

		return nil
	}
	return fmt.Errorf("exhausted retries: %w", lastErr)
}

Step 4: Dead-End Checking and Circular Reference Verification

After applying the isolate directive, you must verify that the modified flow graph contains no execution loops or dead ends. The pipeline traverses the flow-matrix using depth-first search to detect cycles and ensures every leaf node connects to a valid termination or routing node.

func VerifyGraphIntegrity(matrix *FlowMatrix, startNodeID string) error {
	visited := make(map[string]bool)
	recStack := make(map[string]bool)

	var dfs func(currentID string) error
	dfs = func(currentID string) error {
		visited[currentID] = true
		recStack[currentID] = true

		node, exists := (*matrix)[currentID]
		if !exists {
			return fmt.Errorf("dead-end detected at node %s", currentID)
		}

		// Check conditional edges
		for _, cond := range node.Conditions {
			if visited[cond.TargetID] && recStack[cond.TargetID] {
				return fmt.Errorf("circular-reference detected: %s -> %s", currentID, cond.TargetID)
			}
			if !visited[cond.TargetID] {
				if err := dfs(cond.TargetID); err != nil {
					return err
				}
			}
		}

		// Check fallback/default edge
		if node.DefaultEdge != "" {
			if visited[node.DefaultEdge] && recStack[node.DefaultEdge] {
				return fmt.Errorf("circular-reference detected via fallback: %s -> %s", currentID, node.DefaultEdge)
			}
			if !visited[node.DefaultEdge] {
				if err := dfs(node.DefaultEdge); err != nil {
					return err
				}
			}
		}

		recStack[currentID] = false
		return nil
	}

	return dfs(startNodeID)
}

Step 5: Metrics Tracking, Audit Logging, and CLI Exposure

The final component wraps the decoupling pipeline into a command-line interface. It tracks latency, success rates, and generates structured audit logs. Metrics are stored in memory for this example but can be exported to Prometheus or a logging pipeline.

type DecouplingMetrics struct {
	TotalAttempts   int
	SuccessfulDecouples int
	TotalLatency    time.Duration
}

type AuditLog struct {
	Timestamp    time.Time
	FlowID       string
	NodeRef      string
	Action       string
	Status       string
	LatencyMs    float64
	ErrorMessage string
}

func RunDecoupler(ctx context.Context, cfg OAuthConfig, baseURL, flowID, nodeRef, targetFlowID, fallbackPath string, maxBranch int) error {
	cache := NewTokenCache()
	token, err := cache.GetToken(ctx, cfg)
	if err != nil {
		return fmt.Errorf("authentication failed: %w", err)
	}

	matrix, err := FetchFlow(ctx, baseURL, flowID, token)
	if err != nil {
		return fmt.Errorf("flow fetch failed: %w", err)
	}

	directive := IsolateDirective{
		NodeRef:          nodeRef,
		TargetFlowID:     targetFlowID,
		ConditionalMapping: (*matrix)[nodeRef].Conditions,
		FallbackPath:     fallbackPath,
		IsolateTrigger:   "auto-split",
	}

	if err := ValidateIsolateDirective(directive, matrix, maxBranch); err != nil {
		logAudit(flowID, nodeRef, "validation", "failed", 0, err.Error())
		return fmt.Errorf("validation failed: %w", err)
	}

	start := time.Now()
	err = ApplyAtomicPatch(ctx, baseURL, flowID, token, directive, RetryConfig{MaxRetries: 3, BaseDelay: 2 * time.Second})
	latency := time.Since(start)

	status := "success"
	errMsg := ""
	if err != nil {
		status = "failed"
		errMsg = err.Error()
	} else {
		if graphErr := VerifyGraphIntegrity(matrix, (*matrix)[nodeRef].DefaultEdge); graphErr != nil {
			status = "failed"
			errMsg = fmt.Sprintf("graph verification failed: %s", graphErr)
		}
	}

	logAudit(flowID, nodeRef, "decouple", status, float64(latency.Milliseconds()), errMsg)
	return nil
}

func logAudit(flowID, nodeRef, action, status string, latencyMs float64, errMsg string) {
	log := AuditLog{
		Timestamp:    time.Now(),
		FlowID:       flowID,
		NodeRef:      nodeRef,
		Action:       action,
		Status:       status,
		LatencyMs:    latencyMs,
		ErrorMessage: errMsg,
	}
	jsonLog, _ := json.Marshal(log)
	fmt.Println(string(jsonLog))
}

func main() {
	flag.Parse()
	if len(os.Args) < 5 {
		fmt.Println("Usage: decoupler <base_url> <flow_id> <node_ref> <target_flow_id> <fallback_path> <max_branch>")
		os.Exit(1)
	}

	baseURL := os.Args[1]
	flowID := os.Args[2]
	nodeRef := os.Args[3]
	targetFlowID := os.Args[4]
	fallbackPath := os.Args[5]
	maxBranch := 10
	if len(os.Args) > 6 {
		fmt.Sscanf(os.Args[6], "%d", &maxBranch)
	}

	cfg := OAuthConfig{
		BaseURL:      baseURL,
		ClientID:     os.Getenv("CXONE_CLIENT_ID"),
		ClientSecret: os.Getenv("CXONE_CLIENT_SECRET"),
	}

	ctx := context.Background()
	if err := RunDecoupler(ctx, cfg, baseURL, flowID, nodeRef, targetFlowID, fallbackPath, maxBranch); err != nil {
		fmt.Fprintf(os.Stderr, "Decoupling failed: %s\n", err)
		os.Exit(1)
	}
	fmt.Println("Node decoupled successfully")
}

Complete Working Example

The following file combines authentication, flow fetching, validation, atomic patching, graph verification, and CLI execution into a single runnable module. Save it as main.go, set the environment variables, and execute with go run main.go <base_url> <flow_id> <node_ref> <target_flow_id> <fallback_path> <max_branch>.

package main

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

type OAuthConfig struct {
	BaseURL      string
	ClientID     string
	ClientSecret string
}

type TokenResponse struct {
	AccessToken string `json:"access_token"`
	ExpiresIn   int64  `json:"expires_in"`
	TokenType   string `json:"token_type"`
}

type TokenCache struct {
	mu        sync.Mutex
	token     *TokenResponse
	expiresAt time.Time
}

func NewTokenCache() *TokenCache {
	return &TokenCache{}
}

func (c *TokenCache) GetToken(ctx context.Context, cfg OAuthConfig) (string, error) {
	c.mu.Lock()
	defer c.mu.Unlock()

	if c.token != nil && time.Now().Before(c.expiresAt.Add(-time.Minute)) {
		return c.token.AccessToken, nil
	}

	payload := fmt.Sprintf("grant_type=client_credentials&client_id=%s&client_secret=%s", cfg.ClientID, cfg.ClientSecret)
	req, err := http.NewRequestWithContext(ctx, http.MethodPost, fmt.Sprintf("%s/oauth/token", cfg.BaseURL), bytes.NewBufferString(payload))
	if err != nil {
		return "", fmt.Errorf("creating token request: %w", err)
	}
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")

	client := &http.Client{Timeout: 10 * time.Second}
	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("oauth token error: %d %s", resp.StatusCode, resp.Status)
	}

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

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

type FlowNode struct {
	ID          string      `json:"id"`
	Type        string      `json:"type"`
	Conditions  []Condition `json:"conditions,omitempty"`
	DefaultEdge string      `json:"defaultEdge,omitempty"`
}

type Condition struct {
	Expression string `json:"expression"`
	TargetID   string `json:"targetId"`
}

type FlowMatrix map[string]*FlowNode

func FetchFlow(ctx context.Context, baseURL, flowID, token string) (*FlowMatrix, error) {
	req, err := http.NewRequestWithContext(ctx, http.MethodGet, fmt.Sprintf("%s/api/v2/flow/flows/%s", baseURL, flowID), nil)
	if err != nil {
		return nil, fmt.Errorf("creating flow request: %w", err)
	}
	req.Header.Set("Authorization", "Bearer "+token)
	req.Header.Set("Accept", "application/json")

	client := &http.Client{Timeout: 15 * time.Second}
	resp, err := client.Do(req)
	if err != nil {
		return nil, fmt.Errorf("flow fetch failed: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("flow fetch error: %d", resp.StatusCode)
	}

	var rawFlow struct {
		Nodes []struct {
			ID          string        `json:"id"`
			Type        string        `json:"type"`
			Conditions  []Condition   `json:"conditions,omitempty"`
			DefaultEdge string        `json:"defaultEdge,omitempty"`
		} `json:"nodes"`
	}

	if err := json.NewDecoder(resp.Body).Decode(&rawFlow); err != nil {
		return nil, fmt.Errorf("decoding flow: %w", err)
	}

	matrix := make(FlowMatrix)
	for _, n := range rawFlow.Nodes {
		matrix[n.ID] = &FlowNode{
			ID:          n.ID,
			Type:        n.Type,
			Conditions:  n.Conditions,
			DefaultEdge: n.DefaultEdge,
		}
	}
	return &matrix, nil
}

type IsolateDirective struct {
	NodeRef            string      `json:"nodeRef"`
	TargetFlowID       string      `json:"targetFlowId"`
	ConditionalMapping []Condition `json:"conditionalLogicMapping"`
	FallbackPath       string      `json:"fallbackPath"`
	IsolateTrigger     string      `json:"isolateTrigger"`
}

type DecouplingPayload struct {
	Op    string           `json:"op"`
	Path  string           `json:"path"`
	Value IsolateDirective `json:"value"`
}

func ValidateIsolateDirective(directive IsolateDirective, matrix *FlowMatrix, maxBranchComplexity int) error {
	node, exists := (*matrix)[directive.NodeRef]
	if !exists {
		return fmt.Errorf("nodeRef %s not found in flow-matrix", directive.NodeRef)
	}

	if node.Type != "routing" && node.Type != "decision" {
		return fmt.Errorf("nodeRef %s is type %s, must be routing or decision", directive.NodeRef, node.Type)
	}

	branchCount := len(directive.ConditionalMapping)
	if branchCount > maxBranchComplexity {
		return fmt.Errorf("conditional branches %d exceed maximum-branch-complexity %d", branchCount, maxBranchComplexity)
	}

	if directive.FallbackPath == "" {
		return fmt.Errorf("fallbackPath is required for safe isolate iteration")
	}

	if _, exists := (*matrix)[directive.FallbackPath]; !exists {
		return fmt.Errorf("fallbackPath %s does not exist in flow-matrix", directive.FallbackPath)
	}

	return nil
}

type RetryConfig struct {
	MaxRetries int
	BaseDelay  time.Duration
}

func ApplyAtomicPatch(ctx context.Context, baseURL, flowID, token string, directive IsolateDirective, cfg RetryConfig) error {
	payload := []DecouplingPayload{
		{
			Op:    "add",
			Path:  fmt.Sprintf("/nodes/%s/isolateDirective", directive.NodeRef),
			Value: directive,
		},
	}

	jsonData, err := json.Marshal(payload)
	if err != nil {
		return fmt.Errorf("marshaling patch payload: %w", err)
	}

	var lastErr error
	for i := 0; i <= cfg.MaxRetries; i++ {
		req, err := http.NewRequestWithContext(ctx, http.MethodPatch, fmt.Sprintf("%s/api/v2/flow/flows/%s", baseURL, flowID), bytes.NewBuffer(jsonData))
		if err != nil {
			return fmt.Errorf("creating patch request: %w", err)
		}
		req.Header.Set("Authorization", "Bearer "+token)
		req.Header.Set("Content-Type", "application/json-patch+json")
		req.Header.Set("Accept", "application/json")

		client := &http.Client{Timeout: 20 * time.Second}
		resp, err := client.Do(req)
		if err != nil {
			lastErr = fmt.Errorf("patch request failed: %w", err)
			continue
		}
		defer resp.Body.Close()

		if resp.StatusCode == http.StatusTooManyRequests {
			lastErr = fmt.Errorf("rate limited (429)")
			time.Sleep(cfg.BaseDelay * time.Duration(math.Pow(2, float64(i))))
			continue
		}

		if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusAccepted {
			lastErr = fmt.Errorf("patch failed: %d", resp.StatusCode)
			continue
		}

		var result struct {
			Message string `json:"message"`
			Status  string `json:"status"`
		}
		if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
			lastErr = fmt.Errorf("decoding patch response: %w", err)
			continue
		}

		if result.Status != "success" {
			lastErr = fmt.Errorf("patch status not success: %s", result.Status)
			continue
		}

		return nil
	}
	return fmt.Errorf("exhausted retries: %w", lastErr)
}

func VerifyGraphIntegrity(matrix *FlowMatrix, startNodeID string) error {
	visited := make(map[string]bool)
	recStack := make(map[string]bool)

	var dfs func(currentID string) error
	dfs = func(currentID string) error {
		visited[currentID] = true
		recStack[currentID] = true

		node, exists := (*matrix)[currentID]
		if !exists {
			return fmt.Errorf("dead-end detected at node %s", currentID)
		}

		for _, cond := range node.Conditions {
			if visited[cond.TargetID] && recStack[cond.TargetID] {
				return fmt.Errorf("circular-reference detected: %s -> %s", currentID, cond.TargetID)
			}
			if !visited[cond.TargetID] {
				if err := dfs(cond.TargetID); err != nil {
					return err
				}
			}
		}

		if node.DefaultEdge != "" {
			if visited[node.DefaultEdge] && recStack[node.DefaultEdge] {
				return fmt.Errorf("circular-reference detected via fallback: %s -> %s", currentID, node.DefaultEdge)
			}
			if !visited[node.DefaultEdge] {
				if err := dfs(node.DefaultEdge); err != nil {
					return err
				}
			}
		}

		recStack[currentID] = false
		return nil
	}

	return dfs(startNodeID)
}

type AuditLog struct {
	Timestamp    time.Time `json:"timestamp"`
	FlowID       string    `json:"flowId"`
	NodeRef      string    `json:"nodeRef"`
	Action       string    `json:"action"`
	Status       string    `json:"status"`
	LatencyMs    float64   `json:"latencyMs"`
	ErrorMessage string    `json:"errorMessage,omitempty"`
}

func logAudit(flowID, nodeRef, action, status string, latencyMs float64, errMsg string) {
	logEntry := AuditLog{
		Timestamp:    time.Now(),
		FlowID:       flowID,
		NodeRef:      nodeRef,
		Action:       action,
		Status:       status,
		LatencyMs:    latencyMs,
		ErrorMessage: errMsg,
	}
	jsonLog, _ := json.Marshal(logEntry)
	fmt.Println(string(jsonLog))
}

func RunDecoupler(ctx context.Context, cfg OAuthConfig, baseURL, flowID, nodeRef, targetFlowID, fallbackPath string, maxBranch int) error {
	cache := NewTokenCache()
	token, err := cache.GetToken(ctx, cfg)
	if err != nil {
		return fmt.Errorf("authentication failed: %w", err)
	}

	matrix, err := FetchFlow(ctx, baseURL, flowID, token)
	if err != nil {
		return fmt.Errorf("flow fetch failed: %w", err)
	}

	directive := IsolateDirective{
		NodeRef:            nodeRef,
		TargetFlowID:       targetFlowID,
		ConditionalMapping: (*matrix)[nodeRef].Conditions,
		FallbackPath:       fallbackPath,
		IsolateTrigger:     "auto-split",
	}

	if err := ValidateIsolateDirective(directive, matrix, maxBranch); err != nil {
		logAudit(flowID, nodeRef, "validation", "failed", 0, err.Error())
		return fmt.Errorf("validation failed: %w", err)
	}

	start := time.Now()
	err = ApplyAtomicPatch(ctx, baseURL, flowID, token, directive, RetryConfig{MaxRetries: 3, BaseDelay: 2 * time.Second})
	latency := time.Since(start)

	status := "success"
	errMsg := ""
	if err != nil {
		status = "failed"
		errMsg = err.Error()
	} else {
		if graphErr := VerifyGraphIntegrity(matrix, (*matrix)[nodeRef].DefaultEdge); graphErr != nil {
			status = "failed"
			errMsg = fmt.Sprintf("graph verification failed: %s", graphErr)
		}
	}

	logAudit(flowID, nodeRef, "decouple", status, float64(latency.Milliseconds()), errMsg)
	return nil
}

func main() {
	flag.Parse()
	if len(os.Args) < 6 {
		fmt.Println("Usage: decoupler <base_url> <flow_id> <node_ref> <target_flow_id> <fallback_path> [max_branch]")
		os.Exit(1)
	}

	baseURL := os.Args[1]
	flowID := os.Args[2]
	nodeRef := os.Args[3]
	targetFlowID := os.Args[4]
	fallbackPath := os.Args[5]
	maxBranch := 10
	if len(os.Args) > 6 {
		fmt.Sscanf(os.Args[6], "%d", &maxBranch)
	}

	cfg := OAuthConfig{
		BaseURL:      baseURL,
		ClientID:     os.Getenv("CXONE_CLIENT_ID"),
		ClientSecret: os.Getenv("CXONE_CLIENT_SECRET"),
	}

	ctx := context.Background()
	if err := RunDecoupler(ctx, cfg, baseURL, flowID, nodeRef, targetFlowID, fallbackPath, maxBranch); err != nil {
		fmt.Fprintf(os.Stderr, "Decoupling failed: %s\n", err)
		os.Exit(1)
	}
	fmt.Println("Node decoupled successfully")
}

Common Errors & Debugging

Error: 400 Bad Request (Invalid Patch Format)

• What causes it: The JSON Patch payload does not conform to RFC 6902, or the path field targets a non-existent node index. NICE CXone validates patch operations strictly.
• How to fix it: Verify the nodeRef matches an exact id in the flow response. Ensure the op is add, replace, or remove. Check that the isolateDirective object contains all required fields.
• Code showing the fix: Validate the nodeRef against the FlowMatrix before constructing the patch payload. The ValidateIsolateDirective function handles this check.

Error: 401 Unauthorized or 403 Forbidden

• What causes it: The OAuth token has expired, the client credentials are incorrect, or the assigned scopes do not include flow:flows:write.
• How to fix it: Regenerate the token using the TokenCache logic. Verify the Developer Portal client has both flow:flows:read and flow:flows:write scopes assigned.
• Code showing the fix: The GetToken method automatically refreshes when expiration approaches. If 403 persists, update the client scope in the CXone admin console.

Error: 429 Too Many Requests

• What causes it: The CXone API enforces per-client rate limits. Rapid decoupling iterations trigger throttling.
• How to fix it: Implement exponential backoff. The ApplyAtomicPatch function includes a retry loop with math.Pow(2, float64(i)) delay scaling. Increase BaseDelay if throttling persists.
• Code showing the fix: See the RetryConfig and retry loop inside ApplyAtomicPatch.

Error: Graph Verification Failure (Circular Reference or Dead End)

• What causes it: The fallbackPath or conditional targets point to nodes that eventually route back to the isolated node, or point to deleted nodes.
• How to fix it: Review the flow-matrix adjacency list. Ensure fallbackPath routes to a stable termination or queue node. Update the ConditionalMapping targets to avoid recursive loops.
• Code showing the fix: The VerifyGraphIntegrity function performs depth-first traversal with a recursion stack. It returns explicit error messages identifying the exact edge causing the loop or dead end.

Official References

• NICE CXone Flow API Documentation
• NICE CXone OAuth 2.0 Authentication
• RFC 6902 JSON Patch Specification
• Go net/http Package Documentation