querying-markdown

mq is "jq for Markdown" — it parses a .md file into a node stream and lets you select, filter, and transform by structure (.h2, .code("rust"), .link) instead of by line-matching. Reach for it when the task is structural: "every H2 title", "all bash code blocks", "a table of contents", "strip the frontmatter". For plain substring search, grep is still the right tool; for code (not prose) structure, use tree-sitting.

Before you use mq: is this actually a structural task?

mq parses the whole document into a node tree before it answers, and that parse cost is real (see Empirical findings). Most "query a markdown file" tasks don't need it. Decide first, using the target — not the file type: