How APIs Work with Warehouse Management Software

• APIs allow your warehouse management system (WMS) to exchange data instantly with the rest of your tech stack, eliminating manual work and keeping orders, stock, and shipping information accurate in real time.

• Strong API connections prevent common fulfillment bottlenecks—like overselling, delayed updates, and repeated data entry—so your team can scale order volume without adding extra labor.

• With the open API in Descartes Peoplevox™, you can integrate key systems, automate fulfillment workflows, trigger reports and notifications, and stay flexible as your ecommerce operation grows.

APIs matter because ecommerce warehouses move fast. When your warehouse management system (WMS) can’t exchange data cleanly with your ecommerce platform, shipping system, or enterprise resource planning (ERP) program, you feel the impact immediately: delays, stock inaccuracies, and frustrated customers.

This guide breaks down how APIs actually work with warehouse management software and why they’re essential if you want to scale without adding headcount.

What is an API?

API stands for Application Programming Interface, a way for programmers to communicate with an application without needing access to databases and source code. Think of it as a standard plug socket for digital systems. Anything can easily plug into it as long as the plug follows the same standard.

To be more technical, APIs consist of an exact specification produced by the providers of an application and/or service, which programmers must follow if they wish to use that service. This specification covers the available functionality, how it must be used, and the formats accepted as inputs or outputs.

When a platform like Peoplevox WMS offers an open API endpoint, developers can connect other applications to it and share or extract data as required. This helps all the software systems and applications work together in a functional business ecosystem.

Need to know more about the Peoplevox API? Keep reading or contact us

How do APIs work?

Whenever a system wants to access a dataset from another application, it must send a properly formatted request through the API. This is because only a certain amount of data is available to access, and it must be requested in a particular language unique to each application.

The API is a middleman of sorts, checking what is allowed, accepting requests, and returning the data to the system that requested it. It also tells programmers what they can request, precisely how they have to ask for it, and how to receive it.

How an API works with a WMS

When another system, such as your Shopify site, needs warehouse data, it sends a properly formatted request through the WMS API. Here’s an example of what the workflow would look like.

Let’s say an order comes in through Shopify. With an API connection:

• The order syncs instantly into your WMS.

• Warehouse staff pick from real-time stock levels.

• Your shipping platform receives weights and dimensions from the WMS.

• Tracking updates sync back to Shopify automatically.

The API stands between the WMS and all your other programs, automatically pushing data between them. This lets accounts, customer relations, and sales systems exchange information more efficiently. No exporting. No re-entering data. No bottlenecks in your fulfillment workflow. 

Curious what API-led fulfillment looks like in action? Talk to our team

Why are APIs important?

Uniting disconnected systems

Most ecommerce companies nowadays are running several software systems internally: IMS/OMS, WMS, ERP, shipping software, accounting software, returns management, and a multichannel listing management system.

Giving these individual programs the ability to communicate directly and work together is increasingly important for both financial and collaborative reasons. You could always use an all-in-one ecommerce operations platform, or you can custom-build your tech stack using APIs.

Saving time and preventing errors

When systems are connected via an API, convoluted and time-consuming tasks can be streamlined into much more straightforward and easier-to-manage processes. Because the programs automatically share data, you can eliminate manual data entry and key entry errors, making your company more efficient. This also reduces operational costs.

Generating new revenue streams

You can also use APIs to generate additional revenue streams and even form entirely new companies. Uber is the perfect example of this, using APIs to amalgamate Google Maps for mapping and location services, Braintree for payments, Twilio for SMS, and Oracle for its database requirements. Through API connectivity, you can combine diverse programs into a unified, marketable solution.

What happens when a WMS runs without strong API connections?

• Stockouts and overselling: Sales channels don’t update fast enough as orders are picked.

• Slow fulfillment: Orders arrive in batches instead of real time.

• Manual data entry: Every extra click and keystroke increases the risk of mistakes.

• Delayed shipping updates: Customers wait longer for status and tracking notifications.

If this sounds familiar, we can help you streamline these workflows — Request a demo

What can I do with the API for Peoplevox WMS?

At Descartes, we recognize that you need best-in-class connectivity to remain competitive. That’s why Peoplevox includes an open API to exchange all major data required to operate your warehouse. It can push data to external applications via the API, including product data, sales orders, purchase orders, and more. With the Peoplevox API, you can:

Unite your tech stack

This connectivity allows you to adopt a flexible approach to integrating your different systems. Whether you use an inventory management system, ERP, order management system, returns software, shipping platform, or any other software, you can connect to our open API endpoint. All you need is a set of valid credentials for your Peoplevox installation.

Fulfill orders faster

With your tech stack connected to Peoplevox, your warehouse team can eliminate manual fulfillment processes, such as updating order status, emailing customers tracking information, adjusting inventory levels, and generating pick lists. With seamless data transfer across platforms, workers can speed up fulfillment.

Trigger reports and notifications

You can run the Peoplevox system and generate user-defined reports via the API, subscribe to notifications about important warehouse events, like changes to item availability. You can also choose the data you want to receive and the format you receive it in.

Stay at the forefront of innovation

At Descartes, we continuously update Peoplevox, so you will always have access to the data and connectivity you need. Technology changes fast, and we help customers stay ahead with technological innovation for logistics and supply chain.

Accelerate warehouse operations

The Peoplevox WMS helps your warehouse team do what ecommerce businesses need most: fulfill orders quickly, accurately, and without unnecessary labor. When you’re expanding order volume and trying to speed up fulfillment, Peoplevox has the mature, reliable connectivity you need to succeed.

Want to see how Peoplevox works in real warehouses?