Modifying Genesys Cloud Task Router Worker Capacity via API with Go

What You Will Build

• A Go module that atomically patches worker capacity settings for a routing queue using the Genesys Cloud CX Task Router API.
• The code constructs RoutingQueueMember payloads, validates capacity constraints, executes idempotent HTTP PATCH operations with 429 retry logic, and synchronizes events with external resource managers.
• This tutorial is written in Go 1.21+ using the official platform-client-sdk-go and standard library HTTP clients.

Prerequisites

• OAuth Client Credentials grant with scopes: routing:queue:update, routing:worker:read, routing:member:update
• Genesys Cloud Go SDK v8+ (github.com/mypurecloud/platform-client-sdk-go/v8)
• Go 1.21+ runtime environment
• External dependencies: go get github.com/mypurecloud/platform-client-sdk-go/v8

Authentication Setup

Genesys Cloud uses OAuth 2.0 Client Credentials for server-to-server integrations. The SDK handles token acquisition and automatic rotation, but you must configure the environment variables explicitly.

package main

import (
    "context"
    "fmt"
    "log"
    "os"

    "github.com/mypurecloud/platform-client-sdk-go/v8/platformclientv2"
)

func setupConfiguration() *platformclientv2.Configuration {
    cfg, err := platformclientv2.NewConfiguration()
    if err != nil {
        log.Fatalf("Failed to initialize SDK configuration: %v", err)
    }

    cfg.SetBaseURL("https://api.mypurecloud.com")
    cfg.SetClientID(os.Getenv("GENESYS_CLIENT_ID"))
    cfg.SetClientSecret(os.Getenv("GENESYS_CLIENT_SECRET"))

    // SDK automatically acquires and caches tokens.
    // We disable token caching to force explicit refresh demonstration in production.
    cfg.SetTokenCacheEnabled(false)

    return cfg
}

The SDK’s Configuration object manages the /oauth/token endpoint internally. When the access token expires, subsequent API calls trigger a silent refresh. You must ensure your client has the routing:member:update scope, or the PATCH operation returns a 403 Forbidden response.

Implementation

Step 1: Worker Status Validation and Offline Checking

Before modifying capacity, you must verify the worker exists and determine their current online status. Genesys Cloud routing engines ignore capacity updates for workers in a hard offline state. This step implements the offline-worker checking pipeline.

func validateWorkerStatus(ctx context.Context, routingAPI *platformclientv2.RoutingApi, workerID string) (bool, error) {
    // GET /api/v2/routing/workers/{workerId}
    worker, resp, err := routingAPI.GetRoutingWorker(ctx, workerID)
    if err != nil {
        if resp != nil && resp.StatusCode == 404 {
            return false, fmt.Errorf("worker %s not found", workerID)
        }
        return false, fmt.Errorf("worker status check failed: %w", err)
    }

    // Evaluate availability-window logic
    if worker.Status == nil || worker.Status.Value == nil {
        return false, fmt.Errorf("worker status is undefined")
    }

    statusValue := *worker.Status.Value
    offlineStates := map[string]bool{
        "offline": true,
        "notavailable": true,
        "systembusy": true,
    }

    if offlineStates[statusValue] {
        log.Printf("Worker %s is in offline state: %s. Capacity update will be deferred.", workerID, statusValue)
        return false, nil
    }

    return true, nil
}

The GetRoutingWorker call maps to GET /api/v2/routing/workers/{workerId}. The response includes the current routing status. If the worker is offline, the system skips the capacity patch to prevent routing engine conflicts. The function returns a boolean indicating whether the worker is eligible for scaling.

Step 2: Payload Construction and Schema Validation

Capacity modifications require a RoutingQueueMember payload containing the worker reference, capacity directive, and maximum capacity percentage. You must validate these values against task-constraints before sending them to the API.

type CapacityScaleDirective struct {
    WorkerID                string  `json:"worker_id"`
    QueueID                 string  `json:"queue_id"`
    TargetCapacity          float32 `json:"target_capacity"`
    MaximumCapacityPct      int32   `json:"maximum_capacity_percentage"`
    WrapUpTimeoutMs         int64   `json:"wrap_up_timeout_ms"`
}

func validateScaleDirective(directive CapacityScaleDirective) error {
    // task-constraints validation
    if directive.TargetCapacity <= 0 {
        return fmt.Errorf("capacity must be greater than zero")
    }
    if directive.TargetCapacity > 10.0 {
        return fmt.Errorf("capacity exceeds system maximum of 10.0")
    }
    if directive.MaximumCapacityPct < 100 || directive.MaximumCapacityPct > 200 {
        return fmt.Errorf("maximum capacity percentage must be between 100 and 200")
    }
    return nil
}

func buildPatchPayload(directive CapacityScaleDirective) map[string]interface{} {
    return map[string]interface{}{
        "worker": map[string]string{
            "id": directive.WorkerID,
        },
        "capacity":                directive.TargetCapacity,
        "maximumCapacityPercentage": directive.MaximumCapacityPct,
        "wrapUpTimeout":           directive.WrapUpTimeoutMs,
    }
}

The CapacityScaleDirective struct maps directly to the RoutingQueueMember schema. The validation function enforces Genesys Cloud limits: capacity cannot exceed 10.0, and maximum capacity percentage must fall within the 100-200 range. The buildPatchPayload function constructs the exact JSON structure required by the PATCH endpoint.

Step 3: Atomic HTTP PATCH Execution with Retry Logic

Genesys Cloud supports atomic updates via PATCH /api/v2/routing/queues/{queueId}/members. You must handle 429 Too Many Requests responses with exponential backoff to prevent rate-limit cascades. This step also simulates load-balance-calculation verification.

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

type PatchResponse struct {
    Worker struct {
        ID   string `json:"id"`
        Name string `json:"name"`
    } `json:"worker"`
    Capacity                float32 `json:"capacity"`
    MaximumCapacityPercentage int32 `json:"maximumCapacityPercentage"`
}

func executeAtomicPatch(ctx context.Context, cfg *platformclientv2.Configuration, queueID string, payload map[string]interface{}) (*PatchResponse, error) {
    // Retrieve access token from SDK configuration
    accessToken, err := cfg.GetAccessToken(ctx)
    if err != nil {
        return nil, fmt.Errorf("token acquisition failed: %w", err)
    }

    jsonData, err := json.Marshal([]interface{}{payload})
    if err != nil {
        return nil, fmt.Errorf("payload serialization failed: %w", err)
    }

    // PATCH /api/v2/routing/queues/{queueId}/members
    url := fmt.Sprintf("%s/api/v2/routing/queues/%s/members", cfg.GetBaseURL(), queueID)
    
    var lastErr error
    for attempt := 0; attempt < 3; attempt++ {
        req, err := http.NewRequestWithContext(ctx, http.MethodPatch, url, bytes.NewBuffer(jsonData))
        if err != nil {
            return nil, fmt.Errorf("request creation failed: %w", err)
        }

        req.Header.Set("Authorization", "Bearer "+accessToken)
        req.Header.Set("Content-Type", "application/json")
        req.Header.Set("Accept", "application/json")

        client := &http.Client{Timeout: 15 * time.Second}
        resp, err := client.Do(req)
        if err != nil {
            lastErr = fmt.Errorf("network error: %w", err)
            time.Sleep(time.Duration(attempt+1) * 2 * time.Second)
            continue
        }
        defer resp.Body.Close()

        if resp.StatusCode == 429 {
            log.Printf("Rate limited (429). Retrying in %d seconds...", attempt+1)
            time.Sleep(time.Duration(attempt+1) * 3 * time.Second)
            continue
        }

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

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

        return &patchResp, nil
    }

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

The PATCH operation sends an array containing the single member update. Genesys Cloud processes this atomically. The retry loop handles 429 responses with progressive delays. The function returns the updated member object for downstream verification.

Step 4: Metrics Tracking, Webhook Synchronization, and Audit Logging

Production scaling requires latency tracking, success rate calculation, external resource manager synchronization, and immutable audit trails. This step implements the monitoring and governance pipeline.

import (
    "fmt"
    "log"
    "time"
)

type ScaleMetrics struct {
    LatencyMs   float64
    SuccessRate float64
    TotalOps    int
    SuccessOps  int
}

func (m *ScaleMetrics) RecordOperation(success bool, duration time.Duration) {
    m.TotalOps++
    if success {
        m.SuccessOps++
    }
    m.LatencyMs = float64(duration.Milliseconds())
    if m.TotalOps > 0 {
        m.SuccessRate = float64(m.SuccessOps) / float64(m.TotalOps) * 100
    }
}

func dispatchWebhookSync(workerID string, newCapacity float32) {
    // Simulates external-resource-manager alignment
    log.Printf("WEBHOOK_SYNC | worker=%s | capacity=%f | timestamp=%s", 
        workerID, newCapacity, time.Now().UTC().Format(time.RFC3339))
}

func generateAuditLog(workerID string, queueID string, oldCapacity float32, newCapacity float32, success bool) {
    auditEntry := map[string]interface{}{
        "event_type": "worker_capacity_modification",
        "worker_id":  workerID,
        "queue_id":   queueID,
        "old_capacity": oldCapacity,
        "new_capacity": newCapacity,
        "status":     map[bool]string{true: "success", false: "failed"}[success],
        "timestamp":  time.Now().UTC().Format(time.RFC3339),
        "source":     "automated_scale_modifier",
    }
    auditJSON, _ := json.Marshal(auditEntry)
    log.Printf("AUDIT_LOG | %s", string(auditJSON))
}

The ScaleMetrics struct tracks operation duration and success rates. The dispatchWebhookSync function emits structured logs that your external resource manager can consume via a log shipper or direct HTTP callback. The generateAuditLog function creates an immutable governance record for compliance and debugging.

Complete Working Example

The following script combines all steps into a single executable module. Replace the environment variables with your Genesys Cloud credentials.

package main

import (
    "bytes"
    "context"
    "encoding/json"
    "fmt"
    "io"
    "log"
    "net/http"
    "os"
    "time"

    "github.com/mypurecloud/platform-client-sdk-go/v8/platformclientv2"
)

type CapacityScaleDirective struct {
    WorkerID             string  `json:"worker_id"`
    QueueID              string  `json:"queue_id"`
    TargetCapacity       float32 `json:"target_capacity"`
    MaximumCapacityPct   int32   `json:"maximum_capacity_percentage"`
    WrapUpTimeoutMs      int64   `json:"wrap_up_timeout_ms"`
}

type PatchResponse struct {
    Worker struct {
        ID   string `json:"id"`
        Name string `json:"name"`
    } `json:"worker"`
    Capacity                float32 `json:"capacity"`
    MaximumCapacityPercentage int32 `json:"maximumCapacityPercentage"`
}

type ScaleMetrics struct {
    LatencyMs   float64
    SuccessRate float64
    TotalOps    int
    SuccessOps  int
}

func (m *ScaleMetrics) RecordOperation(success bool, duration time.Duration) {
    m.TotalOps++
    if success {
        m.SuccessOps++
    }
    m.LatencyMs = float64(duration.Milliseconds())
    m.SuccessRate = float64(m.SuccessOps) / float64(m.TotalOps) * 100
}

func main() {
    ctx := context.Background()
    cfg := setupConfiguration()
    routingAPI := platformclientv2.NewRoutingApi(cfg)

    directive := CapacityScaleDirective{
        WorkerID:             os.Getenv("GENESYS_WORKER_ID"),
        QueueID:              os.Getenv("GENESYS_QUEUE_ID"),
        TargetCapacity:       2.5,
        MaximumCapacityPct:   150,
        WrapUpTimeoutMs:      60000,
    }

    if err := validateScaleDirective(directive); err != nil {
        log.Fatalf("Schema validation failed: %v", err)
    }

    metrics := &ScaleMetrics{}
    startTime := time.Now()

    // Step 1: Offline-worker checking
    isOnline, err := validateWorkerStatus(ctx, routingAPI, directive.WorkerID)
    if err != nil {
        log.Fatalf("Worker validation error: %v", err)
    }
    if !isOnline {
        log.Printf("Worker is offline. Skipping capacity update.")
        return
    }

    // Step 2 & 3: Atomic PATCH with retry
    payload := buildPatchPayload(directive)
    resp, err := executeAtomicPatch(ctx, cfg, directive.QueueID, payload)
    duration := time.Since(startTime)

    success := err == nil
    metrics.RecordOperation(success, duration)

    // Step 4: Governance and sync
    if success {
        dispatchWebhookSync(directive.WorkerID, resp.Capacity)
        generateAuditLog(directive.WorkerID, directive.QueueID, 1.0, resp.Capacity, true)
        log.Printf("Capacity updated successfully. New capacity: %f", resp.Capacity)
    } else {
        generateAuditLog(directive.WorkerID, directive.QueueID, 1.0, directive.TargetCapacity, false)
        log.Printf("Capacity update failed: %v", err)
    }

    log.Printf("Metrics | Latency: %.0fms | SuccessRate: %.1f%% | TotalOps: %d", 
        metrics.LatencyMs, metrics.SuccessRate, metrics.TotalOps)
}

func setupConfiguration() *platformclientv2.Configuration {
    cfg, err := platformclientv2.NewConfiguration()
    if err != nil {
        log.Fatalf("Failed to initialize SDK configuration: %v", err)
    }
    cfg.SetBaseURL("https://api.mypurecloud.com")
    cfg.SetClientID(os.Getenv("GENESYS_CLIENT_ID"))
    cfg.SetClientSecret(os.Getenv("GENESYS_CLIENT_SECRET"))
    cfg.SetTokenCacheEnabled(false)
    return cfg
}

func validateWorkerStatus(ctx context.Context, routingAPI *platformclientv2.RoutingApi, workerID string) (bool, error) {
    worker, resp, err := routingAPI.GetRoutingWorker(ctx, workerID)
    if err != nil {
        if resp != nil && resp.StatusCode == 404 {
            return false, fmt.Errorf("worker %s not found", workerID)
        }
        return false, fmt.Errorf("worker status check failed: %w", err)
    }
    if worker.Status == nil || worker.Status.Value == nil {
        return false, fmt.Errorf("worker status is undefined")
    }
    statusValue := *worker.Status.Value
    offlineStates := map[string]bool{"offline": true, "notavailable": true, "systembusy": true}
    if offlineStates[statusValue] {
        log.Printf("Worker %s is offline: %s. Deferring scale.", workerID, statusValue)
        return false, nil
    }
    return true, nil
}

func validateScaleDirective(directive CapacityScaleDirective) error {
    if directive.TargetCapacity <= 0 || directive.TargetCapacity > 10.0 {
        return fmt.Errorf("capacity must be between 0 and 10.0")
    }
    if directive.MaximumCapacityPct < 100 || directive.MaximumCapacityPct > 200 {
        return fmt.Errorf("maximum capacity percentage must be between 100 and 200")
    }
    return nil
}

func buildPatchPayload(directive CapacityScaleDirective) map[string]interface{} {
    return map[string]interface{}{
        "worker": map[string]string{"id": directive.WorkerID},
        "capacity": directive.TargetCapacity,
        "maximumCapacityPercentage": directive.MaximumCapacityPct,
        "wrapUpTimeout": directive.WrapUpTimeoutMs,
    }
}

func executeAtomicPatch(ctx context.Context, cfg *platformclientv2.Configuration, queueID string, payload map[string]interface{}) (*PatchResponse, error) {
    accessToken, err := cfg.GetAccessToken(ctx)
    if err != nil {
        return nil, fmt.Errorf("token acquisition failed: %w", err)
    }
    jsonData, err := json.Marshal([]interface{}{payload})
    if err != nil {
        return nil, fmt.Errorf("payload serialization failed: %w", err)
    }
    url := fmt.Sprintf("%s/api/v2/routing/queues/%s/members", cfg.GetBaseURL(), queueID)
    var lastErr error
    for attempt := 0; attempt < 3; attempt++ {
        req, err := http.NewRequestWithContext(ctx, http.MethodPatch, url, bytes.NewBuffer(jsonData))
        if err != nil {
            return nil, fmt.Errorf("request creation failed: %w", err)
        }
        req.Header.Set("Authorization", "Bearer "+accessToken)
        req.Header.Set("Content-Type", "application/json")
        req.Header.Set("Accept", "application/json")
        client := &http.Client{Timeout: 15 * time.Second}
        resp, err := client.Do(req)
        if err != nil {
            lastErr = fmt.Errorf("network error: %w", err)
            time.Sleep(time.Duration(attempt+1) * 2 * time.Second)
            continue
        }
        defer resp.Body.Close()
        if resp.StatusCode == 429 {
            log.Printf("Rate limited (429). Retrying in %d seconds...", attempt+1)
            time.Sleep(time.Duration(attempt+1) * 3 * time.Second)
            continue
        }
        if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusCreated {
            body, _ := io.ReadAll(resp.Body)
            return nil, fmt.Errorf("API returned %d: %s", resp.StatusCode, string(body))
        }
        var patchResp PatchResponse
        if err := json.NewDecoder(resp.Body).Decode(&patchResp); err != nil {
            return nil, fmt.Errorf("response decoding failed: %w", err)
        }
        return &patchResp, nil
    }
    return nil, fmt.Errorf("exhausted retries: %w", lastErr)
}

func dispatchWebhookSync(workerID string, newCapacity float32) {
    log.Printf("WEBHOOK_SYNC | worker=%s | capacity=%f | timestamp=%s", 
        workerID, newCapacity, time.Now().UTC().Format(time.RFC3339))
}

func generateAuditLog(workerID string, queueID string, oldCapacity float32, newCapacity float32, success bool) {
    auditEntry := map[string]interface{}{
        "event_type": "worker_capacity_modification",
        "worker_id":  workerID,
        "queue_id":   queueID,
        "old_capacity": oldCapacity,
        "new_capacity": newCapacity,
        "status":     map[bool]string{true: "success", false: "failed"}[success],
        "timestamp":  time.Now().UTC().Format(time.RFC3339),
        "source":     "automated_scale_modifier",
    }
    auditJSON, _ := json.Marshal(auditEntry)
    log.Printf("AUDIT_LOG | %s", string(auditJSON))
}

Common Errors & Debugging

Error: 403 Forbidden

• Cause: The OAuth client lacks the routing:member:update or routing:queue:update scope.
• Fix: Navigate to the Genesys Cloud admin console, open the OAuth application settings, and add the missing scopes. Regenerate the client secret if you modified the scope list.
• Code showing the fix: Verify scope presence before initialization.

// Add to setupConfiguration()
requiredScopes := []string{"routing:member:update", "routing:queue:update", "routing:worker:read"}
// Validate against your client configuration in the admin console

Error: 429 Too Many Requests

• Cause: Exceeding the Task Router API rate limits (typically 100 requests per second for member updates).
• Fix: The executeAtomicPatch function implements exponential backoff. If cascading failures occur, reduce batch sizes or implement a token bucket rate limiter before calling the endpoint.
• Code showing the fix: Increase retry delay or add jitter.

time.Sleep(time.Duration(attempt+1) * 3 * time.Second + time.Duration(rand.Intn(500))*time.Millisecond)

Error: 422 Unprocessable Entity

• Cause: The capacity or maximumCapacityPercentage values violate Genesys Cloud schema constraints.
• Fix: Run the validateScaleDirective function before sending the PATCH request. Ensure capacity does not exceed 10.0 and maximum percentage falls within 100-200.
• Code showing the fix: Add explicit range checks.

if directive.TargetCapacity > 10.0 || directive.MaximumCapacityPct > 200 {
    return fmt.Errorf("values exceed Genesys Cloud routing constraints")
}

Official References

• Update Routing Queue Member API Documentation
• Genesys Cloud Go SDK Reference
• OAuth Client Credentials Flow
• Task Router Capacity Configuration Guide