mktoc (make table of contents) is a CLI tool written in Rust to generate Table of Contents in Markdown files. It can be hooked up to execute on file save with third-party extensions like “Run on Save” for VSCode.



mktoc provides a few options and has sensible default values, see below.

$ mktoc
$ mktoc -m 4 -M 2

$ mktoc -h

mktoc [FLAGS] [OPTIONS] [file]

-h, --help       Prints help information
-s, --stdout     If set will output to stdout instead of replacing content in file
-V, --version    Prints version information

-M, --max-depth <max-depth>    Maximum heading level [env: MKTOC_MAX_DEPTH=]  [default: 6]
-m, --min-depth <min-depth>    Minimum heading level [env: MKTOC_MIN_DEPTH=2]  [default: 1]

<file>     [default:]

The Markdown file must contain the following HTML comment:

<!-- BEGIN mktoc -->
<!-- END mktoc -->

or optionally, it can contain a inline config

<!-- BEGIN mktoc {"min_depth": 2, "max_depth": 4, "wrap_in_details": true} -->
<!-- END mktoc -->

The ToC will be placed inside the comment. is used for CLI parameter setup and parsing which is a great library for handling CLI parameters in Rust.


As a library mktoc provides one main function: mktoc::make_toc(). This function takes the file name and the min and max heading levels as arguments and returns a Result<String, ::std::io::Error>.

There’s lots of text parsing and re-writing involved to get the heading levels right and build the Markdown menu. All of this can be found in the src/ file.

Building mktoc is a great exercise in file parsing. I use the tool everyday with the Run on Save plugin in VSCode to generate Table of Contents in README files, and I like the challenges it brings. Doing all parsing by myself instead of using a finished markdown parser is a great exercise.