Staff of Building adds in new staff items which can be used to speed up building & block placement.
Holding a staff will show a placement range (but a range will only be displayed if you have the required items in your inventory). Clicking with the staff will fill in the selection with the relevant block, which lowers the staff durability and takes the blocks from your inventory.
Staff of Building requires the Fabric Loader and Fabric API to operate. Install Fabric Loader by using the executable found in the first link, or use MultiMC. Place the API jar and the relevant mod jar file into your mods folder and run the game.
For an overview of all available staff tiers, view the GitHub readme.
This mod is MIT. You are free to use the code and assets inside as you see fit.