# Elsa Workflows
[](https://www.nuget.org/packages/Elsa/)
[](https://github.com/elsa-workflows/elsa-core/actions/workflows/ci.yml)
[](https://discord.gg/hhChk5H472)
[]( http://stackoverflow.com/questions/tagged/elsa-workflows )
[](https://www.reddit.com/r/elsaworkflows/)
Elsa is a workflows library that enables workflow execution in any .NET application. Workflows can be defined in a variety of ways:
- Using C# code
- Using a designer
- Using JSON
- Using a custom DSL
## Documentation
Please checkout the [documentation website](https://v3.elsaworkflows.io/) to get started.
## Features
Here are some of the more important features offered by Elsa:
- Execute workflows in any .NET app.
- Supports both short-running and long-running workflows.
- Programming model loosely inspired on WF4 (composable activities).
- Support for complex activities such as Sequence, Flowchart and custom composite activities (which are like mini-workflows that can be used as activities).
- Ships with a workflows designer web component (currently supports Flowchart diagrams only).
## Console Examples
### Hello World
The following is a simple Hello World workflow created as a console application. The workflow is created using C#.
```csharp
using Elsa.Extensions;
using Elsa.Workflows.Core.Activities;
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 workflow = new WriteLine("Hello World!");
// Resolve a workflow runner to run the workflow.
var workflowRunner = serviceProvider.GetRequiredService();
// Run the workflow.
await workflowRunner.RunAsync(workflow);
```
Outputs:
```shell
Hello World!
```
### Sequential workflows
To build workflows that execute more than one step, choose an activity that can do so. For example, the `Sequence` activity lets us add multiple activities to execute in sequence (plumbing code left out for brevity):
```csharp
// Create a workflow.
var workflow = new Sequence
{
Activities =
{
new WriteLine("Hello World!"),
new WriteLine("Goodbye cruel world...")
}
};
```
Outputs:
```shell
Hello World!
Goodbye cruel world...
```
### Conditions
The following demonstrates a workflow where it asks the user to enter their age, and based on this, offers a beer or a soda:
```csharp
// Declare a workflow variable for use in the workflow.
var ageVariable = new Variable();
// Declare a workflow.
var workflow = new Sequence
{
// Register the variable.
Variables = { ageVariable },
// Setup the sequence of activities to run.
Activities =
{
new WriteLine("Please tell me your age:"),
new ReadLine(ageVariable), // Stores user input into the provided variable.,
new If
{
// If aged 18 or up, beer is provided, soda otherwise.
Condition = new Input(context => ageVariable.Get(context) < 18),
Then = new WriteLine("Enjoy your soda!"),
Else = new WriteLine("Enjoy your beer!")
},
new WriteLine("Come again!")
}
};
```
Notice that:
- To capture activity output, a workflow variable (ageVariable) is used.
- Depending on the result of the condition of the `If` activity, either the `Then` or the `Else` activity is executed.
- After the If activity completes, the final WriteLine activity is executed.
## ASP.NET Examples