jsonschema-markdown

Generate markdown documentation from JSON Schema files. The main goal is to generate documentation that is easy to read and understand.

Can be used as a command line tool or as a library.

Easy to use in CI/CD pipelines, as a Docker image is available.

Installation

pipx install jsonschema-markdown

Usage

To use jsonschema-markdown as a CLI, just pass the filename as an argument and redirect the output to a file.

$ jsonschema-markdown --help
Usage: jsonschema-markdown [OPTIONS] FILENAME

  Load FILENAME and output a markdown version.

  Use '-' as FILENAME to read from stdin.

Options:
  -t, --title TEXT                Do not use the title from the schema, use
                                  this title instead.
  --footer / --no-footer          Add a footer with a link to the project.
                                  [default: footer]
  --empty-columns / --no-empty-columns
                                  Remove empty columns from the output, useful
                                  when deprecated or examples are not used.
                                  [default: empty-columns]
  --resolve / --no-resolve        [Experimental] Resolve $ref pointers.
                                  [default: no-resolve]
  --debug / --no-debug            Enable debug output.  [default: no-debug]
  --examples-format [text|yaml|json]
                                  Format of the examples in the output.
                                  [default: text]
  --version                       Show the version and exit.
  --help                          Show this message and exit.

# Example
$ jsonschema-markdown schema.json > schema.md

Usage with Docker

The jsonschema-markdown command is also available as a Docker image. To use it, you can mount the schema file as a volume.

cat my-schema.json | docker run --rm -i elisiariocouto/jsonschema-markdown - > schema.md

⚠️ Warning: Do not pass the -t flag.

The Docker image is available at:

• elisiariocouto/jsonschema-markdown
• ghcr.io/elisiariocouto/jsonschema-markdown

Usage as a library

To use it as a library, load your JSON schema file as Python dict and pass it to generate. The function will return a string with the markdown.

import jsonschema_markdown

with open('schema.json') as f:
    schema = json.load(f)

markdown = jsonschema_markdown.generate(schema)

Features

The goal is to support the latest JSON Schema specification, 2020-12. However, this project does not currently support all features, but it should support:

• Required fields
• String patterns
• Enumerations
• Default values
• Descriptions and titles
• Nested objects using $defs or definitions
• Basic oneOf, anyOf, allOf functionality
• Arrays
• Integers with minimum, maximum values and exclusives
• Boolean values
• Deprecated fields (using the deprecated option, additionaly searches for case-insensitive deprecated in the field description)
• Supports optional YAML and JSON formatting for examples

Caveats

• This project is still in early development, and the output may change in the future.
• Custom definitions are expected to be in the same file as the schema that uses them, in the definitions or $defs parameter at the root of the document.
• Inline nested definitions are not represented in the output yet. See #18.

---

Examples

Example 1 Input

Given the following JSON Schema:

{
  "$id": "https://example.com/movie.schema.json",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "description": "A representation of a movie",
  "type": "object",
  "required": ["title", "director", "releaseDate"],
  "properties": {
    "title": {
      "type": "string"
    },
    "director": {
      "type": "string"
    },
    "releaseDate": {
      "type": "string",
      "format": "date"
    },
    "genre": {
      "type": "string",
      "enum": ["Action", "Comedy", "Drama", "Science Fiction"]
    },
    "duration": {
      "type": "string"
    },
    "cast": {
      "type": "array",
      "items": {
        "type": "string"
      },
      "additionalItems": false
    }
  }
}

Example 1 Ouput

The following markdown will be generated:

---

jsonschema-markdown

A representation of a movie

Type: object

Property	Type	Required	Possible values	Deprecated	Default	Description	Examples
title	string	✅	string
director	string	✅	string
releaseDate	string	✅	Format: date
genre	string		Action Comedy Drama Science Fiction
duration	string		string
cast	array		string

---

Markdown generated with jsonschema-markdown.

---

Example 2

In tests/model.py you can see a more complex example of a model that is exported as a JSON Schema.

The output can be seen in tests/model.md.