Flow Studio Integration

Integration Direction

The Flow Studio integration is bidirectional: Bidirectional

• Flow Studio → WorkDesk: HIL node suspension creates a record in Process_HILTasks that WorkDesk's sync service detects.
• WorkDesk → Flow Studio: Employee action (approve/submit/acknowledge) triggers WorkDesk to POST to the Flow Studio resume API, resuming the suspended workflow execution.

How Flow Studio Creates HIL Tasks

When a workflow execution reaches a HIL node in Flow Studio, the process engine:

Process_HILTasks Schema

The Process_HILTasks table is the handoff point between Flow Studio and WorkDesk. WorkDesk reads from this table but never writes to it — only the Flow Studio process engine writes HIL task records.

HILTaskSyncService

WorkDesk's backend service that monitors Process_HILTasks and creates corresponding WorkDesk task records:

// HILTaskSyncService.cs — simplified polling loop
public class HILTaskSyncService : BackgroundService
{
    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        while (!stoppingToken.IsCancellationRequested)
        {
            var newHilTasks = await _hilTaskRepo.GetNewTasksSinceAsync(
                _lastSyncCursor,
                tenantIds: _tenantRegistry.ActiveTenantIds,
                ct: stoppingToken);

            foreach (var hilTask in newHilTasks)
            {
                // Create WorkDesk task record
                var workdeskTask = new WorkDeskTask
                {
                    Id             = Guid.NewGuid(),
                    HilTaskId      = hilTask.Id,
                    ExecutionId    = hilTask.ExecutionId,
                    ActorId        = hilTask.AssignedActorId,
                    TenantId       = hilTask.TenantId,
                    Type           = hilTask.TaskType,
                    Title          = hilTask.Title,
                    FormId         = hilTask.FormId,
                    InitialValues  = hilTask.InitialValues,
                    ReviewContent  = hilTask.ReviewContent,
                    DueAt          = hilTask.DueAt,
                    Status         = TaskStatus.Pending,
                    CreatedAt      = DateTime.UtcNow
                };

                await _workdeskTaskRepo.InsertAsync(workdeskTask, stoppingToken);

                // Notify the user via EdgeStream
                await _edgeStream.PublishAsync(
                    topic: $"tasks.{hilTask.AssignedActorId}",
                    payload: new TaskAssignedEvent { Task = workdeskTask },
                    ct: stoppingToken);
            }

            _lastSyncCursor = newHilTasks.LastOrDefault()?.CreatedAt ?? _lastSyncCursor;
            await Task.Delay(TimeSpan.FromSeconds(5), stoppingToken); // poll every 5s
        }
    }
}

Resume API — WorkDesk to Flow Studio

When an employee completes a task in WorkDesk, the frontend calls the WorkDesk backend which in turn calls the Flow Studio resume API:

// WorkDesk Backend — Resume workflow after HIL task completion
POST /api/executions/{executionId}/resume
Authorization: Bearer {service-token}   // machine-to-machine token
Content-Type: application/json

// Request body — approval task
{
  "nodeId":   "hil-approval-node-1",
  "decision": "approved",              // "approved" | "rejected"
  "comment":  "Looks good, approved.", // optional
  "actorId":  "user-guid-here"
}

// Request body — form task
{
  "nodeId":    "hil-form-node-2",
  "formData":  {                       // submitted form field values
    "expenseAmount": 1200.00,
    "category":      "travel",
    "description":   "Q2 conference travel"
  },
  "actorId":   "user-guid-here"
}

// Request body — review task
{
  "nodeId":    "hil-review-node-3",
  "acknowledged": true,
  "actorId":   "user-guid-here"
}

// Response — 200 OK
{
  "executionId": "exec-guid",
  "status":      "running",   // execution resumed and is now running
  "resumedAt":   "2026-05-25T14:32:00Z"
}

What Happens After Resume

Execution History Linkage

WorkDesk's workflow history view links directly to Flow Studio's execution records. An employee can see:

• All executions they triggered (initiator view)
• All executions they participated in as a HIL respondent (participant view)
• The Observer Panel — a read-only drill-down into execution status, node list, and logs — powered by Flow Studio's execution detail API

// WorkDesk calls Flow Studio execution detail API for Observer Panel
GET /api/executions/{executionId}
Authorization: Bearer {userToken}

// Response includes
{
  "executionId": "...",
  "workflowName": "Expense Approval Flow",
  "status": "running",
  "startedAt": "...",
  "nodes": [
    { "nodeId": "node-1", "name": "Start", "status": "completed", "duration": 12 },
    { "nodeId": "hil-1",  "name": "Manager Approval", "status": "completed", "duration": 86400 },
    { "nodeId": "node-3", "name": "Send Notification", "status": "running",  "duration": null }
  ],
  "dataContext": { ... },    // only visible to workflow owner
  "hilTasks": [ ... ]        // HIL tasks associated with this execution
}

Error Handling