transitions_and_workflows.md

Transitions and Workflows

• A Transition is a manual or automatic task that forms the building block of a Workflow.
• A Workflow is a set of steps combined to a finite state machine.

By taking advantage of Transitions and Workflows in Lucidtech's API you can easily structure a complex flow for your documents. A Transition can be either a manual processing step or an automatic operation, and the workflow can therefore combine the power of AI and automation with necessary manual tasks.

Manual Transition

A manual step is often needed for approval of partly automated tasks, or tasks that are not yet automated.

A manual transition can be created in the following manner using Lucidtech's CLI.

las transitions create manual params.json --name Approve --description 'manual approval of invoices'

See the tutorials-section for more information on what to put in the params.json file.

Docker transitions

An automated task does not require any human interaction and requires only a simple docker image. This makes it easy to test your automated task locally and update it in your favorite docker repository. Once you have a docker image you want to use and credentials necessary to run it you are able to create the transition by using Lucidtech's CLI:

las transitions create docker params.json --name Predict --description 'automatic prediction of invoices'

See the tutorials-section for more information on what to put in the params.json file.

Workflow

When you have all necessary transitions ready you can combine them into one workflow, for this example we will make the following workflow.

To achieve this we need to make a workflow-specification, this is a json-file written in a limited version of Amazon States Language (ASL). Just make sure that the resource in each step corresponds to the transitionId for the transition you want to use. An example of a workflow specification for a simple workflow with one manual and one automatic step would look something like this:

{
  "definition": {
    "Comment": "A workflow for prediction and approval", 
    "StartAt": "Predict",
    "States": {
      "Predict": {
        "Type": "Task",
        "Resource": "las:transition:<docker-hex>",
        "Next": "Approve" 
      },
      "Approve": {
        "Type": "Task",
        "Resource": "las:transition:<manual-hex>",
        "End": true
      }
    }   
  }
}