elsa-core/src/samples/console/Elsa.Samples.HelloWorld/Program.cs

using Elsa.Extensions;
using Elsa.Workflows.Core.Activities;
using Elsa.Workflows.Core.Models;
using Elsa.Workflows.Core.Services;
using Microsoft.Extensions.DependencyInjection;

// Setup service container.
var services = new ServiceCollection();

// Add Elsa services.
services.AddElsa();

// Build service container.
var serviceProvider = services.BuildServiceProvider();

// Create a workflow.
var nameVariable = new Variable<string>();

// Define a simple sequential workflow:
var workflow = new Sequence
{
    // Register the name variable.
    Variables = { nameVariable }, 
    
    // Setup the sequence of activities to run.
    Activities =
    {
        new WriteLine("Please tell me your name:"), 
        new ReadLine(nameVariable),
        new WriteLine(context => $"Nice to meet you, {nameVariable.Get(context)}!")
    }
};

// Resolve a workflow runner to run the workflow.
var workflowRunner = serviceProvider.GetRequiredService<IWorkflowRunner>();

// Run the workflow.
await workflowRunner.RunAsync(workflow);