rumdl

rumdl [global-options] command [options] [paths...]

rumdl is a native Rust Markdown linter and formatter in the same spirit as ruff: one binary, fast enough for editors and CI, with automatic fixes and a language server. It implements the common markdownlint rule ids (MD013, MD033, …) plus extra rumdl-only rules, and it can read existing markdownlint / markdownlint-cli2 config files so a first run can be compared without rewriting the project config.Flavors cover GFM, MkDocs, MDX, Quarto, MyST, and others. When no flavor is set, rumdl infers from the file name (`.mdx` → MDX, `.qmd`/`.Rmd` → Quarto, and so on). Results are cached so unchanged files are skipped on later runs.check is the CI/pre-commit command (non-zero if issues remain). fmt is the editor-friendly formatter (zero on successful rewrite). server is the LSP used by the official VS Code and JetBrains plugins.

check [PATHS...]

Lint Markdown files and print diagnostics. Paths override include patterns. Exit `1` if violations remain.

With check, apply automatic fixes. Exit `0` only if nothing is left to fix.

Format Markdown (fixes always on). Exit `0` on success even if some violations cannot be auto-fixed. --check prints a diff and fails if files would change.

Write a default configuration file (`.rumdl.toml`). --pyproject adds a `[tool.rumdl]` section instead.

Import a markdownlint / markdownlint-cli2 config into rumdl's TOML format.

List rules, or print details for one rule id (e.g. `MD013`).

Show the effective configuration. --defaults / --no-defaults filter the dump.

Run the Markdown language server (diagnostics, quick fixes, formatting).

Install or manage the VS Code / Cursor / Windsurf extension.

Print a completion script for `bash`, `zsh`, `fish`, `powershell`, or `elvish`. Omitting SHELL uses `$SHELL`. --list prints supported shells.

Print version information.

Config path, or an inline TOML override such as `MD013.line-length=120`. Repeatable.

Ignore all configuration files and use built-in defaults (`--isolated` is an alias).

Disable rules (comma-separated ids).

Enable only the given rules.

Diagnostic format (`text`, `json`, plus CI formats such as GitHub, GitLab, SARIF, JUnit).

Print diagnostics, suppress summary lines.

With fmt, suppress diagnostics and summaries.

Read Markdown from stdin (and write formatted Markdown to stdout for fmt).

`auto` (default), `always`, or `never`.

Discovery walks parent directories for `.rumdl.toml`, `rumdl.toml`, and `[tool.rumdl]` in `pyproject.toml`. markdownlint JSON/YAML configs are also picked up unless --no-config is set. Inline `<!-- rumdl-disable-next-line MD026 -->` comments suppress individual rules..rumdl.toml / rumdl.toml

Native TOML config: global include/exclude, line length, enabled/disabled rules, and per-rule tables such as `[MD013]`.

Same settings nested under the Python project file.

Per-project lint cache written next to the files. Safe to gitignore.

fmt exiting 0 does not mean the file is clean — only that formatting ran. Use check (or check --fix) when a non-zero status must mean remaining violations.Not every markdownlint plugin/rule is implemented. Flavor auto-detection is filename-based; mixed-flavor trees may need an explicit flavor map in config.

rumdl (Ru(st) MarkDown Linter) was created by rvben as a Rust replacement for the Node.js markdownlint toolchain. It is MIT-licensed and ships as a single static binary (also on PyPI, npm, and crates.io).

markdownlint(1), ruff(1), prettier(1), vale(1), textlint(1), tldr-lint(1)

Source code · Homepage