Editor

Lokus uses a ProseMirror-based editor that renders Markdown as rich text. You write in Markdown or use the toolbar — the editor handles both. Files are stored as .md on disk.

Editor state management

Each open tab maintains its own isolated ProseMirror EditorState, including independent undo/redo history, selection, and scroll position. Switching between tabs restores the exact editor state you left.

Content for inactive tabs is held in an LRU cache with a maximum of 20 entries per editor group. When the cache is full, the least-recently-accessed clean (unsaved) entries are evicted first; dirty (modified) entries are preserved. You can reopen recently closed tabs — the last 20 closed tabs are tracked and can be restored into the focused pane.

Keyboard shortcuts

Text formatting

Action	macOS	Windows/Linux	Markdown
Bold	Cmd+B	Ctrl+B	**text**
Italic	Cmd+I	Ctrl+I	*text*
Strikethrough	Cmd+Shift+S	Ctrl+Shift+S	~~text~~
Inline code	Cmd+E	Ctrl+E	`code`
Highlight	Cmd+Shift+H	Ctrl+Shift+H	==text==
Underline	Cmd+U	Ctrl+U	—

Document structure

Action	macOS	Windows/Linux	Markdown
Heading 1	Cmd+Opt+1	Ctrl+Alt+1	#
Heading 2	Cmd+Opt+2	Ctrl+Alt+2	##
Heading 3	Cmd+Opt+3	Ctrl+Alt+3	###
Bullet list	Cmd+Shift+8	Ctrl+Shift+8	- or *
Ordered list	Cmd+Shift+7	Ctrl+Shift+7	1.
Task list	Cmd+Shift+9	Ctrl+Shift+9	- [ ]
Blockquote	Cmd+Shift+B	Ctrl+Shift+B	>
Horizontal rule	—	—	---

Code and technical

Action	macOS	Windows/Linux	Markdown
Code block	Cmd+Opt+C	Ctrl+Alt+C	```lang
Inline math	—	—	$x^2$
Block math	—	—	$$E=mc^2$$
Callout	Cmd+Opt+C	Ctrl+Alt+C	>[!note]

Section folding

Action	macOS	Windows/Linux
Fold section	Cmd+Opt+[	Ctrl+Alt+[
Unfold section	Cmd+Opt+]	Ctrl+Alt+]
Unfold all	Cmd+Opt+0	Ctrl+Alt+0

Click the fold indicator (triangle) next to any heading to collapse everything under that heading until the next heading of equal or higher level.

Slash commands

Type / on any line to open the command menu. Start typing to filter. Navigate with arrow keys, press Enter to insert.

Writing

Command	What it does
/Heading 1	Big section heading
/Heading 2	Medium section heading
/Heading 3	Small section heading
/Bullet List	Unordered list
/Ordered List	Numbered list
/Task List	Checkbox list
/Quote	Blockquote

Content

Command	What it does
/Image	Triggers image embed autocomplete (![[)
/Table	Opens a size picker grid (up to 6x8), click to insert
/Template	Opens the template picker
/Link to File	Opens the file picker, inserts a [[wiki-link]]
/Simple Task	Insert standalone !task syntax

Code

Command	What it does
/Code	Toggle inline code
/Code Block	Insert a fenced code block

Formatting

Command	What it does
/Highlight	Highlight text
/Strikethrough	Cross out text
/Superscript	Raise text (x^2)
/Subscript	Lower text (H2O)
/Horizontal Rule	Insert a divider

Callouts

Command	What it does
/Note Callout	Blue info callout
/Tip Callout	Green tip callout
/Info Callout	Cyan info callout
/Warning Callout	Orange warning callout
/Danger Callout	Red danger callout
/Success Callout	Green success callout
/Question Callout	Purple question callout
/Example Callout	Gray example callout

Math

Command	What it does
/Inline Math	Opens the math formula modal for inline LaTeX
/Block Math	Opens the math formula modal for display LaTeX

Code blocks

Type three backticks followed by a language name, then press Space to create a syntax-highlighted code block:

```javascript
const greeting = "hello";
```

Supported languages include: JavaScript, TypeScript, Python, Java, C, C++, C#, Go, Rust, PHP, Ruby, Swift, Kotlin, CSS, HTML/XML, JSON, YAML, Bash/Shell, SQL, and Markdown. Short aliases work too — js, ts, py, sh, yml, cs, md.

Inside a code block:

• Enter inserts a newline (stays in the block)
• Backspace at the start of an empty code block converts it back to a paragraph

Mermaid diagrams

Type ```mm (three backticks followed by mm, then a space) to insert a Mermaid diagram block. The block renders the diagram live as you type. Supports flowcharts, sequence diagrams, Gantt charts, and other Mermaid syntax.

Callouts

Callouts (admonitions) are styled blocks for notes, warnings, tips, and other highlighted content. Create them by typing:

>[!note] Optional title

The callout type goes inside [! ]. Available types:

Type	Color	Icon
note	Blue	Info
tip	Green	Lightbulb
warning	Orange	Warning triangle
danger	Red	Alert
info	Cyan	Info
success	Green	Checkmark
question	Purple	Question mark
example	Gray	Book

Collapsible callouts

Add a - after the type to make the callout start collapsed:

>[!warning]- Click to expand
Hidden content here.

Click the toggle button in the callout header to expand or collapse it.

Tables

Insert a table with the /Table slash command. A size picker grid appears — hover to select dimensions (up to 6 rows by 8 columns), then click to insert.

Tables include a header row by default. Use the bubble menu that appears when you click inside a table to add/remove rows and columns.

Images

Embed images using the ![[filename]] syntax. Type ![[ and an autocomplete dropdown appears showing image files in your workspace. Supported formats: PNG, JPG, JPEG, GIF, WebP, SVG, BMP, AVIF.

You can also paste a URL inside ![[ to embed an external image:

![[https://example.com/photo.png]]

The /Image slash command triggers the same ![[ autocomplete.

Math equations

Lokus supports LaTeX math via KaTeX.

Inline math: Wrap in single dollar signs: $x^2 + y^2 = z^2$

Block math: Wrap in double dollar signs:

$$
\int_0^\infty e^{-x^2} dx = \frac{\sqrt{\pi}}{2}
$$

You can also use the /Inline Math and /Block Math slash commands to open a formula editor with a live preview.

Symbol shortcuts

Type :shortcode: to insert special symbols. Works for Greek letters, math symbols, arrows, and more.

Examples:

Shortcode	Symbol
:alpha:	α
:beta:	β
:theta:	θ
:pi:	π
:omega:	ω
:Delta:	Δ
:Sigma:	Σ
:arrow:	→
:leftarrow:	←
:uparrow:	↑
:downarrow:	↓
:inf:	∞

The full set includes all Greek letters (lowercase and uppercase), arrows, math operators, logic symbols, and set operations. You can define custom symbols in Preferences.

Markdown paste

Paste Markdown text into the editor and it converts to rich text automatically. The editor detects Markdown formatting in clipboard content and compiles it to HTML before inserting.

Pasting inside a code block inserts plain text — no conversion happens.

Editor modes

Lokus has three editor modes, saved per file:

• Edit — Full rich text editing
• Live — Live preview of Markdown rendering
• Reading — Read-only rendered view

Section folding

Click the triangle icon next to any heading to fold/unfold the content beneath it. Fold state is saved per note in localStorage. Folding collapses all content between the heading and the next heading of equal or higher level.

Plugin extensions

The editor supports plugin-provided extensions. Plugins can:

• Register custom ProseMirror nodes and marks
• Add new slash commands to the / menu
• Subscribe to editor events
• Provide autocomplete suggestions

Plugin slash commands appear alongside built-in commands in the slash menu.