MSON is short for Markdown Syntax for Object Notation, and it’s a way to represent data structures in a human readable plain text form. This tutorial will take you though the basics of MSON and how you can use MSON to describe a data structure.


MSON is available for API Blueprint documents.

Data structures in MSON

To get started, we’re going to create a data structure in MSON to represent a Person which has a name.

A data structure to store a Person could be represented in MSON using the following:

# Person

+ name

Here we’ve declared our own named type called “Person”. A heading is one or more # symbols followed by a string representing the name of our data structure. By default, named types like Person are object types.

An object is constructed with properties, and in this case we’ve listed them below the heading in a list. Lists are created by putting each list item on its own line and preceding each line with either a +, * or -.

In our Person data structure, we have a single property called name. Similarly to our Person definition, we can declare the type that our property is, with round brackets. For example, we can declare that our name is a string using + name (string). By default, properties on objects are string’s unless specified to another type, as in our above example we have omitted the string type definition.

We can attach a description for our name property by following the type definition with a dash (-) followed by the description.

+ name (string) - The Person's name

We may also specify a sample value for the person’s name by preceding the property name by a colon (:) and then the value.

+ name: Kyle (string) - The Person's name

NOTE: It’s important to note, that if a sample value contains reserved characters such as :, (,), <, >, {, }, [, ], _, *, -, +, ` then the sample value must be wrapped in a code-block using back-ticks:

+ name: `Spencer-Churchill` (string) - The Person's name

So far we have used the object and string types. MSON includes a total of 6 base types. Three of these base types are primitive types such as boolean, string and number. There are also three structure types called array, enum and object. Let’s use some of these new types to create another data structure.

# Company

+ name: Apiary
+ founder (Person)
+ founded: 2011 (number) - The year in which the company was founded


When declaring a named type, you may also inherit from another type. For example, we could declare a data structure called “Administrator” which inherits from the Person type.

# Administrator (Person)

+ role (string) - The administrators role

When inheriting from another data structure, all of the parents properties will be inherited. For example, our Administrator structure will contain the name property from our previous definition.


It’s also possible to nest other data structures directly without a data structure instead of referencing another type as we have done above between our Company and Person.

# Company

+ name: Apiary
+ founder (Person)
+ address
    + street: 235 Ninth Street
    + city: San Francisco
    + state: California

In this example, we’ve declared a property called address which is a nested structure within our Company.


In this case, since we have inline properties within our address property, the default type for the address is object instead of string.

Additional Learning

You can find more examples of MSON, along with additional information from the MSON Specification.