3.0.9 • Public • Published


OpenAPI / Swagger / AsyncAPI / Semoasa definition to Slate / Shins compatible markdown

Build Tested on Tested on Mermade OpenAPIs Known Vulnerabilities

Widdershins adverb:

  • In a direction contrary to the sun's course;
  • anticlockwise;
  • helping you produce static documentation from your OpenAPI 3.0 / Swagger 2.0 / AsyncAPI 1.x / Semoasa 0.1.0 definition

Widdershins screenshot


  • As of v3.0.0 Widdershins no longer expands the definition of OpenAPI body parameters / requestBodies by default, unless they have an inline schema. You can restore the old behaviour by using the --expandBody option.
  • You may limit the depth of schema examples using the --maxDepth option. The default is 10.
  • To omit schemas entirely, please copy and customise the template.
  • As of v3.x you must use the --harmony flag if running on Node.js 4

To install

  • Clone the git repository, or
  • npm install [-g] widdershins, or
  • yarn global add widdershins
node widdershins [options] {input-file|url} [[-o] output markdown]
  --expandBody          Expand requestBody properties in parameters    [boolean]
  --headings            Levels of headings to expand in TOC[number] [default: 2]
  --omitBody            Omit top-level fake body parameter object      [boolean]
  --resolve             Resolve external $refs                         [boolean]
  --summary             Use summary instead of operationId for TOC     [boolean]
  --verbose             Increase verbosity                             [boolean]
  -h, --help            Show help                                      [boolean]
  --version             Show version number                            [boolean]
  -c, --code            Turn generic code samples off                  [boolean]
  -d, --discovery       Include WebAPI discovery data       [boolean]
  -e, --environment     Load config/override options from file          [string]
  -i, --includes        List of files to include, comma separated       [string]
  -l, --lang            Automatically generate list of languages for code
                        samples                                        [boolean]
  -m, --maxDepth        Maximum depth for schema examples          [default: 10]
  -o, --outfile         File to write output markdown to                [string]
  -r, --raw             Output raw schemas not example values          [boolean]
  -s, --search          Whether to enable search or not, default true
                                                       [boolean] [default: true]
  -t, --theme           Syntax-highlighter theme to use                 [string]
  -u, --user_templates  directory to load override templates from       [string]
  -x, --experimental    For backwards compatibility only, ignored      [boolean]


var converter = require('widdershins');
var options = {}; // defaults shown
options.codeSamples = true;
//options.language_tabs = [];
//options.loadedFrom = sourceUrl;
//options.user_templates = './user_templates';
options.templateCallback = function(templateName,stage,data) { return data };
options.theme = 'darkula'; = true;
options.sample = true; // set false by --raw
options.schema = true; // set false by --noschema
options.discovery = false;
options.includes = [];
options.summary = false;
options.headings = 2;
  // str contains the converted markdown

The headings option is currently only supported by Shins, not Slate which lacks this feature.

To only include a subset of the pre-defined language-tabs, or to rename their display-names, you can override the options.language_tabs:

options.language_tabs = [{ 'http': 'HTTP' }, { 'javascript': 'JavaScript' }, { 'javascript--nodejs': 'Node.JS' }, { 'python': 'Python' }, { 'ruby': 'Ruby' }];

If you need to support a version of Slate <v1.5.0 (or a renderer which also doesn't support display-names for language-tabs, such as node-slate, slate-node or whiteboard), you can use the --environment option with the included whiteboard_env.json file to simply achieve this.

The loadedFrom option is only needed where the OpenAPI / Swagger definition does not specify a host, and (as per the OpenAPI specification) the API endpoint is deemed to be based on the source URL the definition was loaded from.

Note that the list of included files is simply passed into the header of the markdown file, they are actually included by Slate or the alternative you use.

To see the list of highlight-js syntax highlighting themes, click here. WebAPI discovery data is included if the discovery option above is set true. See the W3C WebAPI Discovery Community Group for more information.

Language tabs

Widdershins supports the x-code-samples vendor-extension to completely customise your documentation. Alternatively, you can edit the default code-samples in the templates sub-directory, or override them using the user_templates option to specify a directory containing your templates.

Widdershins supports the use of multiple language tabs with the same language (i.e. plain Javascript and Node.Js). To use this support you must be using Slate (or one of its ports compatible with) version 1.5.0 or higher. Shins versions track Slate version numbers.

Template parameters

Templates are compiled with doT.js.

Templates have access to a data object with a range of properties based on the document context.

If you specify an options.templateCallback function, it will be called before and after each template, with three parameters, the template name, the stage, ('pre' or 'post') and the current data object. You can mutate the data object in any way you see fit, as long as you return it. Content in the data.append property will be appended to the current output stream.

User templates

To override a .dot template, you need to copy over the child .def partials as well.

To override a .def partial, you need to copy over the parent .dot template as well. For OpenAPI 3 this will be except for parameters, responses and callbacks, which are children of the template.

This means it is usually easiest to copy all .dot and .def files to your user templates directory. A visual diff tool which can run across two directories (such as Meld or WinMerge) may be useful in bringing in changes from Widdershins updates.


To run a test-suite:

node testRunner {path-to-APIs}

The test harness currently expects .yaml or .json files and has been tested against

Comparison between this and other OpenAPI / Swagger to Slate tools

Blog posting by the author of Widdershins.


Thanks to @latgeek for the logo.

Widdershins in the wild

Please feel free to add a link to your API documentation here.

Widdershins and Shins

If you need a wrapper around both Widdershins and Shins, why not consider the following projects:

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npm i openapi-to-nolink-markdown

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