1.16/20w06 update: It seems like the 1.15 version of the mod works as well, as long as you update the Fabric API (hint: https://www.curseforge.com/minecraft/mc-mods/fabric-api/files/2875599)
New: The Fabric 1.14.4 version removed the GUI, instead, it changes the way the MC GUI behaves. The Fabric 1.14.4 version works with 1.15, 1.15.1, 1.15.2 as well.
- Click to execute a trade once (as opposed to just selecting it)
- Shift-Click to execute a trade as often as possible
- Ctrl-Click to prepare the trade (just like a normal click in the original GUI )
Sorry, no Forge version planned, as I believe Fabric is a much better alternative.
This is a mod for people who trade with villagers a lot. It does not add any functioniality to villagers, and it doesn't allow you to do anything you can't do in vanilla Minecraft, but it allows you to do the same things with a lot less clicks and mouse movements. Because of this, it can be used with standard, unmodded, servers, You should still check your server owner if they're ok with you using it, but as long as your server has a "no unfair advantage" policy, they may allow it.
Please note that if the mod works for you locally, but not on your server, then the server owner may have installed some anticheat plugin that prevents fast-clicking the player inventory. In that case, please ask your server owner to reconsider. If they refuse, you have my sympathies, but I won't build some anti-anticheat-code into my mod; after all, if an owner decides they want to run a broken server, they have the right to do so. You, as a user, have the right to play somewhere else, of course.
When you open a villager trading window, you'll get a list of all item trades the villager offers next to it. This list includs enchantments in the case of smiths and librarians, and shows you at a glance which trades are enabled and which aren't. Clicking on a trade will execute it once, without you needing to move items to/from the merchant UI.
This image is actually a bit outdated; since 1.2, you won't get green/red dye to show enabled trades. They have been replaced by a red stop sign (trade locked), green arrow (trade available), and white arrow (trade available but the player lacks the resources to trade).
To make sure the mod doesn't slow down your minecraft, it has been optimized using jprofiler (https://www.ej-technologies.com/products/jprofiler/overview.html).