Connecting inventory systems of merchants to marketplace

Question

Before I start: I have absolutely no clue about programming whatsoever and basically just want to know if the thing I need is possible (within an appropriate timeframe and budget).

I have a marketplace and merchants who want to sell products on my marketplace. BUT these merchants also have a physical store.

So what I need is a program/system that is connected to the inventory systems of the merchants, which will synchronise the inventory every time actions happen. So something is bought in the offline store, inventory goes down in the online store as well and vice versa.

The biggest problem: Almost every merchant has a different inventory system and I dont know if it's possible to develop a program that is compatible with every inventory system.

Another problem: What i know, the inventory systems merchants have, have interfaces, which enable merchants to connect their self-created online shop with their offline store, so their inventory is synchronised. However, some said it costs money to activate those interfaces. My questions is if it's necessary that those interfaces are activated when I want to connect my not yet developed system with theirs?

If such thing is possible, perhaps someone can tell me how much it cost and how long it takes to program such a thing.

Ps: I don't know if all inventory systems are build up the same but I'm located in Germany if that's important.

I would appreciate any help I can get!

Answer 1

Generally StackOverflow is more about specific programming questions, but that's not going to stop me from answering as best I can:)

It would be impossible, or very tedious, to build a connected system if any of the merchants don't have an interface. Also, fun fact, you'll more often see interfaces called APIs (which just stands for application programming interface), so it may be helpful to look for any mention of that on their websites.

I think you may be right, unrestricted access to some APIs may, in some cases, be behind a pay wall, but it totally depends on the developer of the API. However, it doesn't make sense to me that a physical goods retailer would restrict access like that. To be fair I'm no expert, but it might be best to double check. If I'm wrong and they do restrict access, it will probably be worth the money to pay for access because that makes it significantly easier to work with.

I can't really guess how much it will cost, but I don't think it would take more than a week of coding per merchant.

Take this with a lot of skepticism, I've never done any coding work like this.