Human-in-the-Loop Tasks

The Extensions.HumanTasks package adds human task management to workflows — approval gates, manual review steps, escalation, and delegation.

Installation

dotnet add package WorkflowFramework.Extensions.HumanTasks

HumanTaskStep

Creates a task and waits for a human to complete it:

using WorkflowFramework.Extensions.HumanTasks;

var inbox = new InMemoryTaskInbox();

var workflow = new WorkflowBuilder()
    .Step(new HumanTaskStep(inbox, new HumanTaskOptions
    {
        Title = "Review expense report",
        Description = "Please review the attached expense report for Q4.",
        Assignee = "manager@example.com",
        Timeout = TimeSpan.FromHours(48),
        Escalation = new EscalationRule
        {
            Timeout = TimeSpan.FromHours(24),
            EscalateTo = "director@example.com"
        }
    }))
    .Build();

After completion, the context contains:

• HumanTask(Review expense report).TaskId — the task ID
• HumanTask(Review expense report).Outcome — the outcome string
• HumanTask(Review expense report).Status — Approved, Rejected, Completed, etc.

ApprovalStep

A specialized step requiring approval from one or more people:

var workflow = new WorkflowBuilder()
    .Step(new ApprovalStep(inbox, new ApprovalOptions
    {
        Title = "Budget approval",
        Approvers = { "finance@example.com", "cfo@example.com" },
        Mode = ApprovalMode.Sequential,  // or Parallel
        Timeout = TimeSpan.FromHours(24)
    }))
    .If(ctx => (bool)ctx.Properties["Approval.Approved"]!)
        .Step(proceedStep)
    .Else()
        .Step(rejectStep)
    .EndIf()
    .Build();

Approval Modes

Mode	Behavior
Sequential	Approvers are asked one at a time; first rejection stops the chain
Parallel	All approvers are asked simultaneously; all must approve

ITaskInbox

The core abstraction for task lifecycle management:

public interface ITaskInbox
{
    Task<HumanTask> CreateTaskAsync(HumanTask task, CancellationToken ct = default);
    Task<HumanTask?> GetTaskAsync(string taskId, CancellationToken ct = default);
    Task<IReadOnlyList<HumanTask>> GetTasksForAssigneeAsync(string assignee, CancellationToken ct = default);
    Task CompleteTaskAsync(string taskId, string outcome, IDictionary<string, object?>? data = null, CancellationToken ct = default);
    Task DelegateTaskAsync(string taskId, string newAssignee, CancellationToken ct = default);
    Task<HumanTask> WaitForCompletionAsync(string taskId, TimeSpan timeout, CancellationToken ct = default);
}

Completing Tasks Externally

From your API or UI, complete tasks via the inbox:

// Approve
await inbox.CompleteTaskAsync(taskId, "approved");

// Reject with reason
await inbox.CompleteTaskAsync(taskId, "rejected", new Dictionary<string, object?>
{
    ["reason"] = "Budget exceeded policy limits"
});

// Delegate to someone else
await inbox.DelegateTaskAsync(taskId, "alternate@example.com");

Task Statuses

Pending → InProgress → Approved | Rejected | Completed | Escalated | Cancelled

Note

InMemoryTaskInbox is suitable for development and testing. For production, implement ITaskInbox against your database or task management system.