Synapse Note
A WYSIWYG markdown editor for VS Code with native theming, wiki-link navigation, and live previews for diagrams, math, and Excalidraw drawings.
A Synapse Note opens on demand — no separate preview pane, no syntax tags cluttering your prose, and the plain text editor stays available whenever you need it (for example, to view a git diff).
Quick start
- Install the extension.
- Right-click any
.md file in the Explorer and pick Open with Synapse Note. Already have the file open in the text editor? Use the Open with Synapse Note button in the editor tab bar, or run it from the command palette.
- To flip a Synapse Note back to the plain text editor — for git diff markers, search decorations, or quick raw-markdown edits — run Synapse Note: Open as Text Editor.
- Want every
.md to open in Synapse Note by default? See Settings below.
- Run Synapse Note: Show Features for an in-app feature tour — every page is itself a Synapse Note, demonstrating the feature it describes.
- Run Synapse Note: Show Skills for a markdown syntax reference — useful for humans and AI agents drafting docs that will be rendered by this editor.
Features
Writing
- Bold, italic, strike,
inline code, ==highlight==, H~2~O subscript, E=mc^2^ superscript
- Floating selection toolbar for one-click formatting
- Slash menu (
/) for inserting any block
Structure
- Headings (H1–H6) with an outline panel
- Lists, ordered lists, task lists with
- [x] checkboxes
- Blockquotes (nestable), tables with row/column controls, horizontal rules
Code
- Fenced code blocks with Shiki syntax highlighting (100+ languages)
- Block decorators:
title="hello.py", linenums, hl_lines="2 3"
- Click a block to edit in CodeMirror with language-aware indent and bracket matching
Math
- Inline
$E = mc^2$ and block $$\int...$$ math via KaTeX
- Click any expression to edit; live error diagnostics
Admonitions
- Obsidian-style callout syntax:
> [!NOTE], > [!WARNING], > [!TIP], etc. — 11 types
Diagrams
- Mermaid — flowcharts, sequence, state, ER, Gantt, pie, sankey, mindmaps
- Excalidraw — embed
.excalidraw files with pan/zoom and live reload
Wiki-links
- Type
[[ for an autocompleting note picker over your workspace
[[Note#Heading]] for deep links, [[Note|alias]] for custom labels- Rename a note → optionally rewrite every link to it (configurable)
Frontmatter
- YAML metadata block at the top of any note, edited as inline rows
Settings
| Setting |
Default |
Description |
synapseNote.updateLinksOnRename |
ask |
When a .md file is renamed, how to handle wiki-links pointing at it. Values: ask, always, never. |
To make Synapse Note the default editor for every .md file — skipping the right-click step — add this to your settings.json:
"workbench.editorAssociations": {
"*.md": "synapse-note.editor"
}
Git diff views, search result previews, and other virtual-document URIs always fall back to the plain text editor, so diff markers and search decorations keep working even with this setting on.
Tech stack
Milkdown 7 (ProseMirror + Remark) · Svelte 5 · Shiki 3 · CodeMirror 6 · KaTeX 0.16 · Mermaid 11 · Excalidraw 0.18 · Vite 6 · esbuild
Status
Pre-release. The editor is daily-driver usable, but features and behavior may change between updates.
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