Book JSON

book.json

Applies to all versions (1.21.1 and 26.2).

book.json is the manifest of a book. It lives at data/<namespace>/vellumli_books/<book>/book.json (or next to an external book in .minecraft/vellumli_books/<book>/book.json). Only the name field is required.

Fields

Field	Type	Default	Description
name	string	(required)	Display name of the book. Used as a translation key (the text itself is shown if no translation exists).
landing_text	string	vellumli.gui.lexicon.landing_info	Text shown on the landing page. Used as a translation key (the text itself is shown if no translation exists).
subtitle	string	""	Subtitle translation key shown under the title while version is the number 0.
version	string	"0"	Edition of the book. See Version and subtitle.
use_resource_pack	boolean	false	Must be true for every book that is not an external book.
dont_generate_book	boolean	false	If true, no book item is generated; supply one with custom_book_item.
custom_book_item	string	""	Item stack string used as the book item when dont_generate_book is true.
pamphlet	boolean	false	Pamphlet mode: the book must have exactly one category and opens directly to its entries.
i18n	boolean	false	If true, category names, entry names and page titles are treated as translation keys.
show_progress	boolean	true	Show the unlock progress bar on the landing page.
show_toasts	boolean	true	Show a toast when new entries are unlocked.
pause_game	boolean	false	Pause the game (singleplayer) while the book GUI is open.
creative_tab	resource location	null	Creative tab to add the generated book item to.
advancements_tab	resource location	null	Advancement tab associated with this book. The advancements tab button is not shown in this build (the screen is not ported yet).
index_icon	string	""	Icon used for the book in the index. An item stack string, or a texture path ending in .png. Empty means use the book item.
macros	object	{}	Extra text macros (see Text formatting).

Appearance

Field	Type	Default	Description
book_texture	resource location	vellumli:textures/gui/book_brown.png	Background GUI texture.
filler_texture	resource location	vellumli:textures/gui/page_filler.png	Texture used by the empty page filler.
crafting_texture	resource location	vellumli:textures/gui/crafting.png	Texture used for recipe and item decorations.
model	resource location	vellumli:book_brown	Item model for the generated book. Resolved under item/.
use_blocky_font	boolean	false	Use the game's default font instead of the uniform font.

Colors

All colors are hexadecimal RGB strings (no #, no alpha).

Field	Default	Description
text_color	000000	Body text color.
header_color	333333	Headers and page titles.
nameplate_color	FFDD00	Book name plate in the header.
link_color	0000EE	Link text color.
link_hover_color	8800EE	Reserved hover color.
progress_bar_color	FFFF55	Filled portion of the progress bar.
progress_bar_background	DDDDDD	Background of the progress bar.

Sound

Field	Type	Default	Description
open_sound	resource location	vellumli:book_open	Sound played when the book opens.
flip_sound	resource location	vellumli:book_flip	Sound played when a page is turned.

Overflow

Field	Type	Default	Description
text_overflow_mode	enum	null	One of OVERFLOW, TRUNCATE, RESIZE. Overrides the global config value for this book.

Version and subtitle

• version equal to 0 (or any value that is not a number) behaves specially:
  • A numeric 0 shows the subtitle translation key under the title.
  • A non-numeric value (for example "dev") shows the "Writer's Edition" label.
• A numeric version other than 0 shows an ordinal edition label such as "3rd Edition", and subtitle is ignored.

Removed fields

extend no longer exists. If a book declares extend, Vellumli throws on load and tells the author to ship the content in a resource pack instead. Outside a resource pack / external book, use_resource_pack set to false also throws.