rumdl - Markdown Linter for VS Code

A lightning-fast Markdown linter for VS Code powered by rumdl, a Rust-based linter with 97.2% markdownlint compatibility and 5x performance improvement.
Features
✅ Real-time linting with 50+ rules and precise column highlighting
✅ One-click auto-fixes for common issues
✅ 5x faster than markdownlint
✅ Markdownlint compatibility
✅ Zero configuration required
✅ Workspace-wide linting support
✅ Custom rule configuration
✅ Status bar integration
✅ Precise error positioning with improved column highlighting (rumdl 0.0.81+)
✅ Bundled rumdl binary - no separate installation required
✅ Cross-platform support with optimized binaries for all platforms
Installation
- Install the extension from the VS Code Marketplace
- That's it! rumdl is bundled with the extension - no additional setup required
The extension includes optimized rumdl binaries for all supported platforms:
- Windows (x64)
- macOS (Intel & Apple Silicon)
- Linux (x64 & ARM64)
Manual Installation (Optional)
If you prefer to use your own rumdl installation:
Install rumdl using one of these methods:
# Using Cargo (Rust)
cargo install rumdl
# Using pip (Python)
pip install rumdl
# Download binary from GitHub releases
# See: https://github.com/rvben/rumdl/releases
Configure the path in VS Code settings:
{
"rumdl.server.path": "/path/to/your/rumdl"
}
Quick Start
- Install the extension from the VS Code Marketplace
- Install rumdl (if not already installed):
# Using cargo
cargo install rumdl
# Using homebrew (macOS)
brew install rumdl
# Using npm
npm install -g rumdl
- Open a Markdown file - linting starts automatically!
Screenshots
Real-time Diagnostics

Quick Fixes

Status Bar Integration

Commands
Access these commands via the Command Palette (Cmd/Ctrl + Shift + P
):
rumdl: Fix All
- Apply all available auto-fixes to the current document
rumdl: Restart Server
- Restart the rumdl language server
rumdl: Show Client Logs
- View extension logs in the output panel
rumdl: Show Server Logs
- View server logs in the output panel
rumdl: Check Extension Status
- Display extension status and configuration
rumdl: Test Configuration Discovery
- Debug configuration file discovery and test rumdl settings
Configuration
The extension uses VS Code's standard configuration system. Open Settings (Cmd/Ctrl + ,
) and search for "rumdl" to configure:
Setting |
Description |
Default |
rumdl.enable |
Enable/disable the extension |
true |
rumdl.configPath |
Path to rumdl configuration file (relative to workspace root or absolute). If not specified, rumdl will auto-discover configuration files in the workspace. |
undefined |
rumdl.rules.select |
Array of rule IDs to enable. Empty array enables all rules. |
[] |
rumdl.rules.ignore |
Array of rule IDs to ignore/disable |
[] |
rumdl.server.path |
Custom path to rumdl binary |
"rumdl" |
rumdl.server.logLevel |
Server log level (error , warn , info , debug , trace ) |
"info" |
Project Configuration
Create a .rumdl.toml
file in your project root for project-specific settings:
# Enable/disable specific rules
[rules]
select = ["MD001", "MD003", "MD022"]
ignore = ["MD013", "MD033"]
# Rule-specific configuration
[rules.MD013]
line_length = 120
code_blocks = false
[rules.MD003]
style = "atx"
# File patterns to include/exclude
[files]
include = ["**/*.md", "**/*.markdown"]
exclude = ["node_modules/**", "target/**"]
Supported File Types
The extension automatically activates for these file extensions:
.md
.markdown
.mdown
.mkd
.mdx
rumdl is built for speed:
Tool |
Time (1000 files) |
Relative Speed |
rumdl |
0.8s |
5x faster |
markdownlint |
4.2s |
baseline |
Rule Compatibility
rumdl supports 97.2% of markdownlint rules:
- ✅ 50+ rules fully implemented
- ✅ Auto-fixes for 40+ rules
- ✅ Custom configuration support
- ✅ Same rule IDs as markdownlint
See the full rule list for details.
Troubleshooting
rumdl not found
If you see "rumdl executable not found":
- Install rumdl: Follow the installation guide
- Check PATH: Ensure rumdl is in your system PATH
- Set custom path: Configure
rumdl.server.path
in settings
Server not starting
If the server fails to start:
- Check logs: Use "rumdl: Show client logs" command
- Verify installation: Run
rumdl --version
in terminal
- Restart server: Use "rumdl: Restart Server" command
- Check configuration: Ensure
.rumdl.toml
is valid
If linting feels slow:
- Check file size: Very large files (>1MB) may be slower
- Exclude patterns: Add exclusions for generated files
- Reduce rules: Disable unused rules in configuration
Development
Building from Source
# Clone the repository
git clone https://github.com/rumdl/rumdl-vscode.git
cd rumdl-vscode
# Install dependencies
npm install
# Build the extension
npm run compile
# Run in development mode
npm run watch
Testing
# Run linting
npm run lint
Contributing
We welcome contributions! Please check the repository for contribution guidelines.
Reporting Issues
When reporting issues, please include:
- VS Code version
- Extension version
- rumdl version (
rumdl --version
)
- Debug information (use "rumdl: Print debug information")
- Sample Markdown file that reproduces the issue
License
This extension is licensed under the MIT License.
Changelog
See CHANGELOG.md for release history.
Enjoy lightning-fast Markdown linting with rumdl! ⚡