You create a door on a flat solid surface that you can see within range. The door is large enough to allow Medium creatures to pass through unhindered. When opened, the door leads to the demiplane of your Great Library. There are no restriction except for size on who may use this door after it's creation. You can close any door you created at least 24 hours ago by using an action, as long as they are on the same plane of existence as you. Creatures inside can use and action to leave the demiplane and appear in an unoccupied space closest to their original entrance. Creatures can always choose to leave the demiplane even if there are no more doors. The material components for subsequent castings of this spell to create more doors include: Small pieces of the door's desired material as well as 375 gold pieces.

The demiplane of the Great Library is created when you cast this spell for the first time and is 30 feet in each dimension.  A warm golden-orange glow fills the room emanating from a dozen floating magic candles that never burn out. The inside is furnished with chairs and tables befitting of its size while the walls are lined with bookshelves. The furniture is made of a simple, inexpensive material that caster desires. All furniture disappears into a puff of white smoke when removed from the demiplane and reappears in its original place. The furniture and other parts of the demiplane cannot be used as spell components. The bookshelves - upon creation of the demiplane - contain up to 60 books and/or tomes (at the DM's discretion). The remaining space in the bookshelves can be filled by bringing books and/or tomes into the demiplane and placing them into a an empty shelf space. When done, they become part of the inventory of the library and when brought outside of the demiplane, disappear and reappear in their shelf space. Books and tomes that count as rare or higher rarity are unaffected by this. The library also has one unseen servant who acts as librarian (and knows the location of every book in the library). Furthermore they very roughly know the contents of all books and may point visitors towards the information they are looking for. They follow the caster's command and see him as the owner of the library. However they will not harm or tarnish the inventory in any way. Any unseen servant that is reduced to 0 hp reappears at the place where it died after 24 hours. The maximum number of simultaneous doors is 3.

You can cast this spell once at 6th level. When you do, the cost of casting increases to 7500 gp (only once) and the library increases to 300 feet in length and width and gains two upper floors (each floor being 30 feat in height). Travelling between the floors is possible via stairs or small teleportation sigils at the beginning and end of the stairs that can be touched as an action and transport the user to their desired floor and staircase (as more staircases are needed for the larger variants of the library). The amount of stairacases is subject to the DM's discretion. The number of unseen servants increases to 30. The number of simultaneous doors increases to 6. The furniture is now made out of comfortable materials of the caster's choosing (at the DM's discretion) and new furniture appears in an appropriate amount. The magic candles turn into small floating chandeliers made of out copper and new chandeliers appear in an appropriate amount.

You can cast this spell once at 9th level . When you do, the cost of casting increases to 75000 gp (only once) and the library increases to 3000 feet and gains 4 upper floors for a total of 6. The number of unseen servants increases to 300. The number of simultaneous doors increases to 18. The furniture is now made out of the finest and most luxurious materials of the caster's choosing (at the DM's discretion) and new furniture appears in an appropriate amount. The magic chandeliers are now made out of gold, large in size and may have gemstones as decorations. New chandeliers appear in an appropriate amount.

If you cast this spell at 9th level everyday for a month the material components worth 75000 gp will be used after the last casting and the library can now gain a new floor whenever the last one's bookshelves are completely filled. Each new floor also gains 50 unseen servants as well as furniture and chandeliers in an appropriate amount. The unseen servants are now able to write books. Their imagination and quality of writing is based on the caster's intelligence, Charisma or Wisdom (whichever is highest). Each unseen servant can create one book every week.These books are simply of an informing or entertaining nature and are not magical. They are automatically added to the library's inventory and can't be removed.