MarkdownHub#

Collaborative Markdown editor with real-time preview, version history, and multi-file repository support.

Phase 1 — Solo Editor MVP (current)#

What's built:

• Auth: Email/password registration and login, plus GitHub/Google OAuth stubs
• Repositories: Create repos with name, description, visibility (private/public/unlisted)
• File management: Create, browse, view, and edit Markdown files within repos
• Split-pane editor: CodeMirror 6 on the left, rendered Markdown on the right
• Auto-save: Saves content after 2s of inactivity (no version created)
• Manual save with version: Creates a named snapshot for version history
• Version history: List all versions, select two to compare
• Diff viewer: Side-by-side diff with line-level add/delete highlighting
• Server-side rendering: Go templates, goldmark for Markdown rendering

Stack#

Running locally#

# Set env vars (or use defaults for dev)
export SESSION_SECRET="your-secret-here"
export BASE_URL="http://localhost:8080"

# Optional: OAuth (skip for password-only auth)
export GITHUB_CLIENT_ID="..."
export GITHUB_CLIENT_SECRET="..."
export GOOGLE_CLIENT_ID="..."
export GOOGLE_CLIENT_SECRET="..."

# Build and run
go build -o markdownhub ./cmd/server
./markdownhub

Server starts on :8080.

What's next#

Phase 2 — Comments#

• Line-anchored comments with content hash drift detection
• Threaded replies (one level)
• Resolve/unresolve
• Gutter indicators in editor

Phase 3 — Collaborative Editing#

• Yjs CRDT via WebSocket
• Real-time multi-user editing
• Presence indicators (cursors, selections)
• Awareness protocol

Project structure#

markdownhub/
├── cmd/server/main.go          # Entry point, routing
├── internal/
│   ├── auth/                   # Sessions, password hashing, OAuth config
│   ├── db/                     # SQLite queries and migrations
│   ├── handler/                # HTTP handlers
│   ├── middleware/              # Auth injection, logging
│   ├── model/                  # Data structs
│   ├── render/                 # Goldmark Markdown rendering
│   └── version/                # Diff computation
├── migrations/                 # SQL migration files
├── static/css/                 # Stylesheets
├── templates/                  # Go HTML templates
├── Dockerfile
└── fly.toml

Note on CodeMirror#

The editor template references CodeMirror 6 modules at /static/vendor/codemirror.js and /static/vendor/codemirror-lang-markdown.js. You'll need to bundle these yourself (or use a CDN). A quick way:

npm init -y
npm install @codemirror/state @codemirror/view @codemirror/lang-markdown codemirror
npx esbuild --bundle --format=esm --outfile=static/vendor/codemirror.js node_modules/codemirror/dist/index.js
npx esbuild --bundle --format=esm --outfile=static/vendor/codemirror-lang-markdown.js node_modules/@codemirror/lang-markdown/dist/index.js

/plugin marketplace add anthropics/claude-code /plugin install frontend-design@claude-code-plugins