PicaMD

Inline-WYSIWYG Markdown editor for macOS. AppKit-native (no Chromium), file-based (no library DB or vault), MIT.

Status: v0.8.0-alpha — first public release. Built on NSTextView, Swift 6 strict concurrency throughout, ad-hoc signed.

Where it sits

	Native AppKit	Inline WYSIWYG	File-based
PicaMD	✓	✓	✓
Typora	✗ (Electron)	✓	✓
Obsidian	✗ (Electron)	✓ (Live Preview)	~ (vault DB on top)
iA Writer	✓	✗ (syntax highlighting only)	✓
MarkEdit	✓	✗ (no live preview)	✓
Bear	✓	partial (proprietary "Polar Bear")	✗ (vault DB)

The combination — AppKit + inline-WYSIWYG + plain files — is empty on the market. That's the niche. Everything else (AI hook, MCP server, themes, export) is built on top.

Editor

• Cursor-aware syntax concealment. The line your cursor sits on shows raw markdown; every other line renders. Move the cursor away, the markers disappear. Move it back, they come back. Same trick Obsidian's Live Preview uses, done natively in AppKit instead of CodeMirror-in-WebView. Works for **, *, ~~, ==, `, #, >, [](), math $, code-fence backticks, <details>.
• Block overlays for tables, images, KaTeX math (offline-bundled), Mermaid diagrams (downloaded on first use). A lazy webview pool caps WKWebView instances at 12 so RAM stays bounded on long docs.
• Outline sidebar with cursor auto-tracking. Frontmatter bar with title + tag chips. Footnote tooltips on [^id] hover.
• Tabs (⌘T), Focus mode (⌃⌘F), Typewriter mode (⌃⌘Y), Command palette (⌘⇧P).

Themes

Three built-in presets — Stock+, Editorial, Tahoe. Four palettes — White, Off-White, Dark Grey, OLED. Seven accents. Body / heading font, heading scale, code-block style — all toggleable in ⌘, Settings. The chosen palette is independent of macOS Light/Dark Mode (use the White palette while macOS is in Dark Mode, if you want).

AI assistance (opt-in)

Off by default. When enabled, you get ⌃⌘1–⌃⌘9 bound to nine starter presets (clean Markdown, summarize, rewrite-natural, extend, fix grammar, translate DE↔EN, formalise, casualise, custom). ⌃Space opens a fuzzy picker over every preset.

Each preset is a name + system prompt + user prompt template + insertion mode (replace selection / append below / blockquote / HTML comment / popover). All editable, all reorderable, all re-bindable. Add your own.

Talks to:

• Anthropic (Claude API)
• OpenAI (or any OpenAI-compatible URL — Groq, Together, vLLM, …)
• Local (LM Studio, Ollama, llama.cpp --api)

API keys go in the macOS Keychain. Endpoint selection is per-preset; the default is whatever's set in Settings → AI → Providers.

Claude Code MCP integration

PicaMD ships with picamd-mcp, a stdio-MCP sidecar embedded in the app bundle. It lets Claude Code (or any MCP client) read and edit currently-open documents through eight tools.

// ~/.config/claude-code/mcp.json
{
  "mcpServers": {
    "picamd": {
      "command": "/Applications/PicaMD.app/Contents/Resources/picamd-mcp"
    }
  }
}

Tool	What it returns
workspace.openDocuments	path / title / line-count for every doc currently in a PicaMD window
workspace.search	substring matches across all open docs
document.metadata	title, frontmatter tags, word/line counts
document.outline	heading hierarchy with line numbers
document.readLines	1-indexed line range
document.readSection	body under a heading by text match
document.replaceLines	atomic line-range write (FileWatcher picks the change up live)
document.appendText	append with paragraph break

The point: Claude can call outline() + readSection("Methods") instead of Read(file) for the whole document — useful for long docs in repeated edit loops. Whether that's worth using over Claude's native Read with `offs

... View full README on GitHub