SOAP vs. REST

Table of contents

• Introduction
• Key difference
• Detailed comparison

Introduction

Ongoing WMS has two different Application Programming Interfaces (APIs) which are intended for connecting systems like business systems (ERPs) and web shops to the WMS:

• Goods Owner SOAP API - based on Simple Object Access Protocol
• Goods Owner REST API - based on Representational state transfer

We also have an automation API which is used when you wish to connect automation equipment like conveyor belts.

In this article we will explain the difference between the Goods Owner SOAP API and the Goods Owner REST API.

Key difference

The key difference between the two APIs is:

• The SOAP API is a large and extensive API which gives the API user wide latitude in how he wishes to control the WMS and which fields to use.
• The REST API is a smaller and more focused API where the API user is offered less choice in how the integration works.

Thus the SOAP API has more functionality, and the REST API is easier to use.

Detailed comparison

Here are some specific comparison points between the APIs.

	SOAP	REST
May create, update and read articles, orders, purchase orders and return orders	Yes	Yes
May cancel orders and purchase orders	Yes	Yes
May attach files to orders and articles	Yes	Yes
May read tracking information from orders	Yes	Yes
May read stock adjustments	Yes	Yes
May read shipments and production orders 1	Yes	No
May read the current stock balance 2	Yes	Yes
May read historical stock balances (from past dates) 2	Yes	No
Allows the API user to read and update a large variety of data fields on the orders, purchase orders and articles 3	Yes	No
Can create kit articles and sub order lines 4	Yes	No
Each order and purchase order must have a unique order number 5	No	Yes
Each article must have a unique article number 5	No	Yes
Allows detailed advising of goods information on purchase orders 6	Yes	No

Shipments and production orders

The following entities can only be managed using the SOAP API, and not by the REST API:

• Shipment (note: this refers to Ongoing WMS' own concept of a shipment. It is unrelated to the "shipments" which transporters such as DHL and UPS have)
• Production order

In our experience, very few integrations need to use these entities.

Stock balances

Both APIs can read stock balances, but only the SOAP API can ask for what the stock balance was at a past date.

Which fields can be used?

The SOAP API allows you to update and read many fields on orders, purchase orders and articles. The REST API gives access to a much smaller selection of fields, making the REST API less complex.

Kit articles and sub order lines

Only the SOAP API may create kit articles, that is, articles which are defined in terms of other articles.

Only the SOAP API may create sub order lines, that is, define order lines which are "children" of another order line.

Unique order, purchase order and article numbers

The REST API has some requirements regarding uniqueness. In the REST API:

• An article (SKU) must have a unique article number.
• An order must have a unique order number.
• A purchase order must have a unique purchase order number.

In the SOAP API, the above are not always required.

Advising detailed goods information on purchase orders

Both the REST API and SOAP API allow you to create purchase orders, which advise the warehouse of which articles and quantities are expected to arrive at the warehouse.

The SOAP API takes this one step further, and allows the API user to also advise exactly which batch numbers, pallet numbers, expiry dates, etc are expected. The REST API does not allow this.