mdsmith

mdsmith is a Markdown linter and formatter for keeping writing neat and consistent. It checks style, readability, structure, and cross-file integrity, and it can auto-fix changes that it can cleanly repair. The project describes itself as fast enough to stay out of the way, and it is meant to work across a whole Markdown tree rather than only on individual files.

Its rule set includes formatting fixes for whitespace, headings, code fences, bare URLs, list indentation, and table alignment. mdsmith fix loops through up to 10 passes and stops when edits stabilize, while mdsmith check provides a read-only counterpart for CI. The tool also supports conventions and renderer flavors through a pinned Markdown convention that selects a curated rule preset and a target renderer flavor. It flags syntax that a chosen flavor will not render, enforces size and readability limits, and can detect verbatim copy-paste across files. In addition, it covers cross-file integrity by flagging broken links and missing anchors, enforcing per-file section schemas, renaming headings without breaking links, and tracking dependencies through includes, catalogs, build inputs, and links.

mdsmith runs in the CLI, as an LSP server, and through integrations for VS Code, Neovim, Obsidian, and Claude Code. Its editor and agent integrations use the same rule engine, and the LSP server provides diagnostics, quick-fixes, and navigation features such as definition, references, symbol search, and call hierarchy over include and catalog directives plus cross-file links. The binary is described as a single static Go binary with no runtime to start. It is available through go install, npm, pip, uvx, mise, asdf, and GitHub Releases, and the page says these installs work offline in locked-down CI because there is no postinstall network call. The project page also points to GitHub, docs, and a migration path from markdownlint.