markdraft 1.0.3

Preview local markdown files with mermaid diagram support.

Markdraft

Preview local markdown files in the browser with GitHub-flavored rendering, mermaid diagrams, math, syntax highlighting, and live reload. Zero runtime dependencies.

$ draft README.md
 * Serving on http://localhost:6419/

Installation

From PyPI

pip install markdraft

Or with uv:

uv tool install markdraft

Standalone executable

Download markdraft.pyz from Releases and run it directly — no installation needed:

python markdraft.pyz README.md

Requires Python 3.10+. On first run, markdraft downloads about 3.5 MB of JavaScript libraries from jsDelivr and caches them in ~/.markdraft/.

Usage

Preview a file:

$ draft README.md
 * Serving on http://localhost:6419/

Preview a directory (serves its README.md):

$ draft .

Open the browser automatically:

$ draft -b README.md

Specify host and port:

$ draft README.md 0.0.0.0:8080

Export to a self-contained HTML file:

$ draft --export README.md
Exporting to README.html

Export with CDN links instead of inlined assets:

$ draft --export --no-inline README.md

Dark mode:

$ draft --theme=dark README.md

The mdraft command is also available as an alias, for environments where draft conflicts with Azure Draft.

Features

• Live reload — file changes are detected and the browser refreshes automatically via Server-Sent Events
• Mermaid diagrams — ```mermaid fenced code blocks rendered by mermaid.js
• Math/LaTeX — $inline$ and $$display$$ math rendered by KaTeX
• Syntax highlighting — code blocks highlighted by highlight.js
• GitHub Alerts — > [!NOTE], > [!TIP], > [!IMPORTANT], > [!WARNING], > [!CAUTION] styled callout boxes
• GeoJSON maps — ```geojson and ```topojson rendered as interactive maps by Leaflet
• STL 3D models — ```stl rendered as rotating 3D views by Three.js
• Task lists — - [x] and - [ ] checkboxes
• Emoji shortcodes — :rocket: → :rocket:, full gemoji set (1,800+ shortcodes)
• GitHub styling — rendered with github-markdown-css
• Export — self-contained HTML files with all assets inlined or linked via CDN
• Zero dependencies — no pip runtime dependencies; rendering is done client-side by cached JavaScript libraries
• Auto/dark/light mode — follows OS preference by default (--theme=auto), or force with --theme=dark / --theme=light
• Standalone executable — download a single .pyz file, no installation required

Rendering Showcase

The examples below exercise every client-side rendering feature. Running draft README.md and checking that each one renders correctly is a quick smoke test for a new installation.

Syntax highlighting

def fibonacci(n: int) -> int:
    a, b = 0, 1
    for _ in range(n):
        a, b = b, a + b
    return a

Mermaid diagrams

graph LR
    A[Markdown file] --> B[HTTP Server]
    B --> C[Browser]
    C --> D[marked.js]
    D --> E[Rendered HTML]

Math / LaTeX

Euler's identity: $e^{i\pi} + 1 = 0$

The Gaussian integral:

$$\int_{-\infty}^{\infty} e^{-x^2} , dx = \sqrt{\pi}$$

GitHub Alerts

[!NOTE] This is a note — useful for supplementary information.

[!TIP] This is a tip — helpful advice for the reader.

[!IMPORTANT] This is important — key information the reader should know.

[!WARNING] This is a warning — something that could cause problems.

[!CAUTION] This is a caution — potential for data loss or security risk.

GeoJSON maps

{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "geometry": {
        "type": "Polygon",
        "coordinates": [[
          [-122.42, 37.78], [-122.42, 37.77], [-122.41, 37.77],
          [-122.41, 37.78], [-122.42, 37.78]
        ]]
      },
      "properties": { "name": "San Francisco" }
    }
  ]
}

Emoji shortcodes

:rocket: :sparkles: :warning: :bug: :white_check_mark: :x: :heart: :star: :fire: :eyes: :tada: :construction:

Task lists

• Syntax highlighting
• Mermaid diagrams
• Math / LaTeX
• GitHub Alerts
• GeoJSON maps
• Task lists
• Emoji shortcodes

Tables

Library	Purpose	Size
marked.js	Markdown rendering	40 KB
highlight.js	Syntax highlighting	40 KB
KaTeX	Math rendering	270 KB
mermaid.js	Diagrams	2.9 MB

CLI Reference

usage: draft [-h] [-V] [--user-content] [--wide] [--clear] [--export]
             [--no-inline] [-b] [--title TITLE] [--norefresh] [--quiet]
             [--theme THEME]
             [path] [address]

Flag	Description
path	File or directory to render (- for stdin)
address	host:port to listen on, or output file for --export
-b, --browser	Open browser tab after server starts
--export	Export to HTML file instead of serving
--no-inline	Use CDN links instead of inlining assets in export
--title TITLE	Override the page title
--theme THEME	Color theme: auto (default), light, or dark
--user-content	Render as GitHub issue/comment style
--wide	Wide layout (with --user-content)
--norefresh	Disable auto-refresh on file change
--quiet	Suppress terminal output
--clear	Clear the cached assets and exit
-V	Show version and exit

Python API

from markdraft import serve, export, clear_cache

# Start a preview server
serve("README.md", port=8080, browser=True)

# Export to HTML
export("README.md", out_filename="preview.html")

# Clear cached CDN assets
clear_cache()

Configuration

Create ~/.markdraft/settings.py to override defaults:

HOST = "0.0.0.0"
PORT = 8080
AUTOREFRESH = True
QUIET = False

The MARKDRAFT_HOME environment variable overrides the config directory (default ~/.markdraft).

Architecture

Markdraft is a thin HTTP server built on Python's http.server. It serves raw markdown via a JSON API and lets the browser handle all rendering:

sequenceDiagram
    participant B as Browser
    participant S as Server (http.server)
    B->>S: GET /
    S-->>B: HTML shell (template + script tags)
    B->>S: GET /__/api/content
    S-->>B: raw markdown as JSON
    Note over B: marked.js renders markdown
    Note over B: KaTeX renders math
    Note over B: highlight.js highlights code
    Note over B: mermaid.js renders diagrams
    B->>S: GET /__/api/refresh (SSE)
    S-->>B: file change notifications

Modules:

Module	Purpose
markdraft/server.py	HTTP server with routing
markdraft/readers.py	File/directory/stdin reading
markdraft/assets.py	CDN asset downloading and caching
markdraft/export.py	Self-contained HTML export
markdraft/watcher.py	File change detection for auto-refresh
markdraft/browser.py	Browser tab opening
markdraft/config.py	Constants, CDN URLs, settings loader
markdraft/command.py	CLI argument parsing

Development

git clone https://github.com/imofftoseethewizard/markdraft
cd markdraft
uv sync
uv run pytest              # 148 tests, ~8s parallel
uv run pyright markdraft/  # type checking
uv run black markdraft/ tests/  # formatting

Acknowledgments

Markdraft began as a fork of Grip by Joe Esposito. Grip is a well-crafted tool for previewing GitHub-flavored markdown locally, and its reader abstractions and CLI design informed markdraft's architecture.

Major changes from Grip

• Zero runtime dependencies — Grip depends on Flask, Markdown, Pygments, requests, docopt, path-and-address, and Werkzeug. Markdraft has no pip dependencies; it uses only the Python standard library.
• Client-side rendering — Grip renders markdown server-side with Python. Markdraft serves raw markdown and renders it in the browser with marked.js, highlight.js, and mermaid.js.
• Math/LaTeX support — $inline$ and $$display$$ math via KaTeX.
• GitHub Alerts — > [!NOTE], > [!WARNING], etc. rendered as styled callout boxes.
• Mermaid diagram support — ```mermaid fenced code blocks rendered as diagrams.
• GeoJSON maps and STL 3D models — interactive maps via Leaflet, rotating 3D model views via Three.js.
• stdlib HTTP server — replaces Flask with http.server.ThreadingHTTPServer.
• Modern Python — requires Python 3.10+, full type annotations, no Python 2 compatibility code.
• uv project management — pyproject.toml with hatchling build backend, managed by uv.
• Security hardening — path traversal protection via Path.relative_to(), symlink escape prevention, case-insensitive </script> escaping in exports.
• Standalone executable — downloadable .pyz file, no installation required.
• GitHub API removed — Grip's primary mode was to POST markdown to the GitHub API for rendering. Markdraft renders entirely offline.

License

MIT