Spines

A spine in Rheo is the backbone or ‘table of contents’ of Typst source files that should be compiled to an output format. It takes its name from the epub specification, in which the spine articulates—or reticulates— the set and order of chapters included.

You can specify a spine’s vertebrae for any output format using an array of glob strings in rheo.toml:

[epub.spine]
title = "My epub"
vertebrae = ["intro.typ", "*.typ"]

Notice how the first entry intro.typ is a specific file, whereas the second *.typ captures a range of files. When a glob string captures a range of source files, they will be ordered lexicographically in the spine.

EPUB

An EPUB must have a spine in order to be valid. By default, Rheo will infer the following spine if not specified:

[epub.spine]
title = "[project folder name]"
vertebrae = ["**/*.typ"]

PDF

By default, Rheo generates one PDF per Typst source file. You can specify a spine for the PDF format in order to reticulate multiple source documents into a single output PDF by indicating the vertebrae and setting merge to true:

[pdf.spine]
title = "My reticulated pdf"
vertebrae = ["intro.typ", "*.typ"]
merge = true

In a PDF generated in this way, relative links will resolve to internal document links that point to the relevant section.

HTML

Rheo does not currently support customizing HTML spines. The default spine uses all Typst files:

[html.spine]
title = "[project folder name]"
vertebrae = ["**/*.typ"]