Linear - Smart Building in Minecraft
Linear mod dramatically simplifies the process of creating straight lines and walls in Minecraft, working in both survival and creative modes.
Easy to use: To start building, simply sneak and hold right mouse button. Then just move the cursor to the desired location and release the button:

The system automatically calculates the number of blocks used - this counter is displayed next to the cursor.
Limitations and visual cues: In survival mode, certain limitations apply. If you don't have enough blocks, are too far away, or try to place too many blocks at once, non-placeable blocks are highlighted in red. The block counter also turns red and shows only the amount that will actually be used. All limitations are configurable.

Variety of Building Modes
Press the G key (configurable) to switch between different building modes. The current mode is displayed in the bottom left corner of the screen (also configurable) when you're holding a block that supports multiple placement.
Five main modes are available:
Line (3 axes): Creates a line that can go in all three directions

Note: Building in air is only available in creative mode by default.
Line (2 axes): Creates a line limited to two directions

Line (1 axis): Creates a line in only one direction

Wall (3 axes): Creates a vertical or horizontal wall in all three directions

Wall (2 axes): Creates a wall limited to two directions

Process control: To cancel building, simply stop sneaking. If you don't want to use multiple placement while sneaking, toggle this function with the V key.
Flexible Configuration
In the configuration, you can adjust the position of the building mode indicator, placement ranges, white and black lists of blocks, and many other parameters.
Building ranges and all other limitations can be individually configured for each player using CraftTweaker integration.