Sit lets you use slabs and stairs as chairs. It is available for Forge and NeoForge on Minecraft 1.12.2 - 26.3.
Right-click the top of a slab or stair with an empty hand to sit down, and press the minecart dismount key (SHIFT by default) to stand up. Half beds work too, and slabs or stairs from other mods are usually supported, with one config option for reach distance. Multiplayer needs it on both sides, so put it on your Minecraft server with one click in the panel and furnish a real café 🪑