Why Notidian

Obsidian has no drawing. OneNote has no markdown. Notion locks your data in the cloud. Concepts has no knowledge management. There is no tool that lets you write and draw in the same note, stores everything as portable markdown files, and runs locally on your device.

Notidian fills that gap.

The Problem

If you think in both text and visuals, you’re forced to split your workflow across multiple apps. Write meeting notes in Obsidian, sketch diagrams in Concepts, manage tasks in TickTick, track events in Google Calendar. Your knowledge lives in five different places with five different formats.

None of these tools were designed to work together. None of them give you true ownership of your data.

What Notidian Is

Notidian is a local-first knowledge management app with an infinite canvas. Every note is a standard markdown file on your filesystem. And every note is also a canvas where you can draw with a GPU-accelerated engine that delivers 60 FPS with 5,000+ strokes.

Write and draw in the same note. Your text is markdown. Your drawings are rendered with WebGPU compute shaders. Both live in a single .md file you can open in any editor.

Core Principles

Your files are yours

Notes are .md files with YAML frontmatter on your local disk. No cloud lock-in, no proprietary database, no export needed. If Notidian disappears tomorrow, you have a folder of markdown files. We evaluated 19 file formats and chose the one where your data outlives the app.

GPU-accelerated drawing

A custom WebGPU engine with compute shaders for brush dynamics, pressure sensitivity, and GPU tessellation. This is not Canvas2D with a WebGL wrapper. This is direct GPU access with WGSL compute shaders — the same technology powering native apps, running in your browser.

Local-first, syncs everywhere

Your workspace lives on your device. Sync through whatever cloud storage you already use — iCloud Drive, Dropbox, Google Drive. No proprietary sync server, no data in transit you don’t control.

Progressive depth

Start with notes and drawings. Add tasks when you need them. Connect your calendar. Over time, Notidian grows to manage PDFs, ebooks, images, and documents — all searchable, all linked to your knowledge graph. But it never becomes a file manager. It manages your workspace.

The Technical Foundation

• WebGPU with WGSL compute shaders for drawing (no WebGL, no Canvas2D)
• Svelte 5 with runes for reactive UI
• Tauri 2 for native desktop and mobile
• LexicalJS for rich text editing overlaid on the canvas
• Rust backend with SQLite metadata cache and Tantivy full-text search
• Markdown files with YAML frontmatter as the storage format

Who This Is For

Individuals who manage personal knowledge. A researcher with 10,000 notes and sketches. A student who handwrites lecture notes and types summaries. A creative professional who thinks visually and writes textually.

This is not a team tool. Sharing is person-to-person — you share a specific note or folder with a partner, a collaborator, a friend. Your personal second brain, with occasional windows you open for others.

What’s Next

Notidian is actively developed. Current priorities:

1. Mobile — iOS and Android via Tauri 2
2. Sync — BYO-cloud file sync will return after the local architecture is finalized
3. AI — Local inference via WebLLM, your notes stay on your device
4. Collaboration — Share notes and folders for collaborative editing

The drawing engine is the technical moat. The markdown format is the trust moat. Together, they make Notidian something no competitor can replicate by adding a feature.