> ## Documentation Index
> Fetch the complete documentation index at: https://docs.versori.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Workflows, Triggers and Tasks

<Note>
  Workflows should not be confused with Durable Workflows, which are covered in the
  [Durable Workflows](/latest/run-sdk/latest/durable-workflows) page. Workflows in this context are not a public
  aspect of the SDK, but are created implicitly when using Triggers and Tasks.
</Note>

A workflow defines a single flow of data through your integration between one or more systems. It is made up of a single
trigger followed by one or more tasks/steps. A project may contain multiple workflows to support complex integrations.

As covered in the [Introduction](/latest/run-sdk/latest/introduction), a workflow is declared by calling the `webhook`
or `schedule` function, followed by one or more steps. This page goes into more detail to explain how to build a
multi-step workflow.

## Triggers

A trigger is created by calling the `webhook` or `schedule` function. On it's own, a trigger is not useful, but it is
the starting point for a workflow as this is what will start the execution of the workflow.

## Tasks

A Trigger exposes a single method, `then()`, which is used to add a task to the trigger and become a new workflow.

<Info>
  Although this is a non-developer facing guide, it's worth noting here that the `then()` signature is similar to
  that of the JavaScript Promise API. In the examples here we always pass a value to the `then()` method, such as the
  return value of a call to `fn()`, however you can pass an arbitrary function where the first parameter is a
  [Context](/latest/run-sdk/latest/context) object just like the Promise API.

  More information about the `then()` and `catch()` methods can be found in the developer guide.
</Info>

```typescript theme={null}
import { webhook, fn } from '@versori/run';

const workflow = webhook('upper-caser')
    .then(
        fn('upper-case', (ctx) => {
            if (typeof ctx.body !== 'string') {
                throw new Error('Body must be a string');
            }

            return ctx.body.toUpperCase();
        })
    );
```

In the example above, we're using the `fn()` task to validate the body of the request is a string, and then uppercases
it. There are various types of tasks which will be covered later.