Describe the solution you'd like

My ultimate goal is to be able to make the use of a warp cost X (configurable) number of Ender Pearls.
There 2 methods I can think of for MyWarp to accomplish this:

1. Utilize economy plugins which provide multiple currencies, and those currencies being item based. I'm not sure if this is possible through Vault or not.
2. Have MyWarp deduct the items from inventory directly.
   Note that if this method is chosen, it might be desirable to be able to utilize ender chest inventory as well, but should be configurable.

Describe alternatives you've considered

The only other way I can think of to accomplish this is to use the PayForCommands plugin. However this has the down side of that if you typo a warp name, or the command results in some other failure, you still get charged anyway. Plus this wouldn't work for signs.

In theory this should be possible using MyWarp's economy integration as long as you are using an economy plugin that is entirely item based and supported by Vault.

I do not have any personal experience with any economy plugin, but did you already try Gringotts? From reading its documentation it looks like it can deduce items directly from inventory if you disable Gringotts' vaults.

MyWarp - in principle - supports multiple currencies because it delegates every action to Vault. The problem is that Vault's API is not designed to support multiple currencies at all (API calls take raw numbers as arguments); plugins that support Vault may offer multiple currencies, but any currency must be reducible to a single one which is handled by Vault. That seems to be the way Gringots does it.

Is there any plugin that implements multiple item based currencies with an API I could hook into?

Otherwise I will investigate if such a feature could be implemented by MyWarp itself without becoming painful to maintain - I suspect some kind of abstraction over a player's inventory and items would be required at core level.

So I went poking around, and it looks like almost all the plugins which offer multiple currencies don't integrate with vault. The only one which I could find which does is The New Economy which from my experience is buggy as hell, and I wouldn't want it anywhere near my server.

So yeah, I guess through vault isn't really much of an option :-(

Another thought: register and trigger events for each of the different actions (warp by command, warp by sign, create warp, etc). Then this behavior can be left up to the user by using skript, TriggerReactor, etc. In my case I could check inventory for an ender pearl, and if I don't find one, cancel the event, and if I do, remove it from inventory and allow event to continue.