Items

One workflow can process one kind of item. For example if you have a workflow for tracking parcels, then the item going through that workflow is 'Parcel'. But there might be several parcels at any given point of time - every one of the parcels has its own state and other attributes.

Some other examples of items:

Example workflow	Item
Loan application procedure	Loan
Escrow payment flow	Payment
Car repair shop	Incident
Car reseller	Car
NFT sales portal	Image
Project funding procedure	Project

Item attributes

Items have characteristics - information to describe every item. This information evolves as the item passes through its workflow. Each attribute also has an attribute type - for example a Color could be Type with values Red|Green|Blue but the attribute Price would be of type Money.

Real world example

As an example imagine a workflow for buying 3D prints. It starts with getting a price quote from the printhouse and ends with the print posted/sent out. This is an overview of the use-cases in this example:

• Client creates a request to get back a quote for a printing job. The request contains of the following attributes as parameters: name, print file, client wallet address, quantity
• A whitelisted Printer can make an offer for the job by also adding the price.
• The client can then either reject or accept the offer. Upon accepting the offer the Client also makes a payment to the Printer.
• If the client rejects the offer the item goes back into Requested state and can be amended by the Client. Client can specify new quantity, amend the file and change the description.
• When the Printout is done (printed), it will get sent out and moved to Shipped status. This transition requires a tracking code as parameter.

The item in this case would be Printout and its properties are as follows:

Printout

Property	Type
Id	Integer
Status	Integer
Name	String
Price	Money
Description	String
STL File Url	String
Client	User
Printer	Restricted User
Quantity	Integer

In the course of the workflow the attributes would change as the item evolves:

Available attribute types

Type	Description	Example
Text	Textual data	Name of item
Integer	Full number	Count
Yes/no	Tickbox	Can pay out funds?
Float	Number with comma	Height
Type	Predetermined list of select words	Shape: Circle, Square, Hexagon
Date	Time with date accuracy	Deadline
Timestamp	Time with second accuract	Created at
Money	Number with comma and currency sign, can be used as payment in select crypto currency	Price
User	Wallet address	Owner
Restricted user	Whitelisted wallet address	Employee
Blob	Any file upload, will be stored in IPFS	Evidence zip
Image	File of image type, will be stored in IPFS	Applicant Photo
Address	A struct with Street, Region, Index, Country selector	Shipping address
Name, email and address	Same as Address but adds person name and email fields	Billing address
Other flow id	Id of an item in another flow	Car model Id

Transient attributes

When adding new items you can mark them as "Transient". The difference with normal attributes is that transient ones will not get saved with the item and will not take storage space on the blockchain.

Benefits of Transient attributes

Why would one use transient attributes?

• If you have a Charity workflow, with a Transition called Donate which takes in a parameter called Donation Amount it makes sense to mark it as "Transient" because the last donation amount would not give any meaningful information. It makes sense to only use it during that donation to create a one-time payment with that amount. Furthermore, one can always find out the historic donations by looking at the blockchain history.
• If you use it as an intermediate variable for the calculation step. For example a transient parameter could be Days (integer), but calculation step would convert it into seconds and store a Deadline (timestamp) instead using the following expression: now() + (Days * 24 * 60 * 60).