Settings

Most of what you would want to change is in the commands — Ctrl/⌘ P, under This window:

Change the theme	the palette the window is drawn in. See themes.
Light or dark	follow the system, or pin one. A theme published in one half only leaves nothing to choose here.
Interface size	how large the window is drawn: fields, buttons, spacing, type.
Reading font size	how large the text you read is set, over the size above.
Sync title and filename	whether renaming one renames the other. See writing notes.

Choosing one writes it down. There is no separate save.

The two sizes are multipliers over what was designed. The interface goes from 0.8 to 2 and the text you read from 0.8 to 1.75; hairlines, borders and focus rings stay one physical line under either. A number outside those bounds is refused, said out loud, and left in the file exactly as you wrote it.

The file

Everything else lives in one file, numen.json, in the folder numen keeps its own things in.

It is yours to edit. Fields you leave out keep their defaults, so a file naming one setting is a complete file. Keys numen does not know are carried through untouched, and a file that does not parse is never written over — numen says so and leaves it alone.

{
  "appearance": {
    "mode": "system",
    "theme": "preset:numen",
    "interface_scale": 1,
    "text_scale": 1
  }
}

What is in it

appearance	the four above.
indexing.embedding	the model that reads your notes so they can be found by meaning. See search by meaning.
indexing.recognition	how a scanned book is read. See reading scanned books.
indexing.proofreading	what corrects a reading afterwards, and nothing by default.
agent	which assistant answers in the panel, and how it is started. See the agent.
naming	whether a note’s title and its filename are kept as one name. See writing notes.

Every setting is the complete list, taken from the application itself.

A key never written back into this file is a key to a service: name the environment variable it is read from, and it stays out of your files.