OpenAPI Specification

(fka Swagger RESTful API Documentation Specification)

Version 2.0

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.

The Swagger specification is licensed under The Apache License, Version 2.0.

Introductions

Swagger? is a project used to describe and document RESTful APIs.

The Swagger specification defines a set of files required to describe such an API. These files can then be used by the Swagger-UI project to display the API and Swagger-Codegen to generate clients in various languages. Additional utilities can also take advantage of the resulting files, such as testing tools.

Revision History

Definitions

Path Templating

Path templating refers to the usage of curly braces ({}) to mark a section of a URL path as replaceable using path parameters.

Mime Types

Mime type definitions are spread across several resources. The mime type definitions should be in compliance with RFC 6838.

Some examples of possible mime type definitions:

  text/plain; charset=utf-8
  application/json
  application/vnd.github+json
  application/vnd.github.v3+json
  application/vnd.github.v3.raw+json
  application/vnd.github.v3.text+json
  application/vnd.github.v3.html+json
  application/vnd.github.v3.full+json
  application/vnd.github.v3.diff
  application/vnd.github.v3.patch

HTTP Status Codes

The HTTP Status Codes are used to indicate the status of the executed operation. The available status codes are described by RFC 7231 and in the IANA Status Code Registry.

Specification

Format

The files describing the RESTful API in accordance with the Swagger specification are represented as JSON objects and conform to the JSON standards. YAML, being a superset of JSON, can be used as well to represent a Swagger specification file.

For example, if a field is said to have an array value, the JSON array representation will be used:

{
   "field" : [...]
}

While the API is described using JSON it does not impose a JSON input/output to the API itself.

All field names in the specification are case sensitive.

The schema exposes two types of fields. Fixed fields, which have a declared name, and Patterned fields, which declare a regex pattern for the field name. Patterned fields can have multiple occurrences as long as each has a unique name.

File Structure

The Swagger representation of the API is made of a single file. However, parts of the definitions can be split into separate files, at the discretion of the user. This is applicable for $ref fields in the specification as follows from the JSON Schemadefinitions.

By convention, the Swagger specification file is named swagger.json.

Data Types

Primitive data types in the Swagger Specification are based on the types supported by the JSON-Schema Draft 4. Models are described using the Schema Object which is a subset of JSON Schema Draft 4.

An additional primitive data type "file" is used by the Parameter Object and the Response Object to set the parameter type or the response as being a file.

Primitives have an optional modifier property format. Swagger uses several known formats to more finely define the data type being used. However, the format property is an open string-valued property, and can have any value to support documentation needs. Formats such as "email", "uuid", etc., can be used even though they are not defined by this specification. Types that are not accompanied by a format property follow their definition from the JSON Schema (except for file type which is defined above). The formats defined by the Swagger Specification are:

Schema

Swagger Object

This is the root document object for the API specification. It combines what previously was the Resource Listing and API Declaration (version 1.2 and earlier) together into one document.

Fixed Fields

Patterned Objects

Info Object

The object provides metadata about the API. The metadata can be used by the clients if needed, and can be presented in the Swagger-UI for convenience.

Fixed Fields

Patterned Objects

Info Object Example:

{
  "title": "Swagger Sample App",
  "description": "This is a sample server Petstore server.",
  "termsOfService": "http://swagger.io/terms/",
  "contact": {
    "name": "API Support",
    "url": "http://www.swagger.io/support",
    "email": "support@swagger.io"
  },
  "license": {
    "name": "Apache 2.0",
    "url": "http://www.apache.org/licenses/LICENSE-2.0.html"
  },
  "version": "1.0.1"
}

title: Swagger Sample App
description: This is a sample server Petstore server.
termsOfService: http://swagger.io/terms/
contact:
  name: API Support
  url: http://www.swagger.io/support
  email: support@swagger.io
license:
  name: Apache 2.0
  url: http://www.apache.org/licenses/LICENSE-2.0.html
version: 1.0.1

Contact Object

Contact information for the exposed API.

Fixed Fields

Patterned Objects

Contact Object Example:

{
  "name": "API Support",
  "url": "http://www.swagger.io/support",
  "email": "support@swagger.io"
}

name: API Support
url: http://www.swagger.io/support
email: support@swagger.io

License Object

License information for the exposed API.

Fixed Fields

Patterned Objects

License Object Example:

{
  "name": "Apache 2.0",
  "url": "http://www.apache.org/licenses/LICENSE-2.0.html"
}

name: Apache 2.0
url: http://www.apache.org/licenses/LICENSE-2.0.html

Paths Object

Holds the relative paths to the individual endpoints. The path is appended to the basePath in order to construct the full URL. The Paths may be empty, due to ACL constraints.

Patterned Fields

Paths Object Example

{
  "/pets": {
    "get": {
      "description": "Returns all pets from the system that the user has access to",
      "produces": [
        "application/json"
      ],
      "responses": {
        "200": {
          "description": "A list of pets.",
          "schema": {
            "type": "array",
            "items": {
              "$ref": "#/definitions/pet"
            }
          }
        }
      }
    }
  }
}

/pets:
  get:
    description: Returns all pets from the system that the user has access to
    produces:
    - application/json
    responses:
      ‘200‘:
        description: A list of pets.
        schema:
          type: array
          items:
            $ref: ‘#/definitions/pet‘

Path Item Object

Describes the operations available on a single path. A Path Item may be empty, due to ACL constraints. The path itself is still exposed to the documentation viewer but they will not know which operations and parameters are available.

Fixed Fields

Patterned Fields

Path Item Object Example

{
  "get": {
    "description": "Returns pets based on ID",
    "summary": "Find pets by ID",
    "operationId": "getPetsById",
    "produces": [
      "application/json",
      "text/html"
    ],
    "responses": {
      "200": {
        "description": "pet response",
        "schema": {
          "type": "array",
          "items": {
            "$ref": "#/definitions/Pet"
          }
        }
      },
      "default": {
        "description": "error payload",
        "schema": {
          "$ref": "#/definitions/ErrorModel"
        }
      }
    }
  },
  "parameters": [
    {
      "name": "id",
      "in": "path",
      "description": "ID of pet to use",
      "required": true,
      "type": "array",
      "items": {
        "type": "string"
      },
      "collectionFormat": "csv"
    }
  ]
}

get:
  description: Returns pets based on ID
  summary: Find pets by ID
  operationId: getPetsById
  produces:
  - application/json
  - text/html
  responses:
    ‘200‘:
      description: pet response
      schema:
        type: array
        items:
          $ref: ‘#/definitions/Pet‘
    default:
      description: error payload
      schema:
        $ref: ‘#/definitions/ErrorModel‘
parameters:
- name: id
  in: path
  description: ID of pet to use
  required: true
  type: array
  items:
    type: string
  collectionFormat: csv

Operation Object

Describes a single API operation on a path.

Fixed Fields

Patterned Objects

Operation Object Example

{
  "tags": [
    "pet"
  ],
  "summary": "Updates a pet in the store with form data",
  "description": "",
  "operationId": "updatePetWithForm",
  "consumes": [
    "application/x-www-form-urlencoded"
  ],
  "produces": [
    "application/json",
    "application/xml"
  ],
  "parameters": [
    {
      "name": "petId",
      "in": "path",
      "description": "ID of pet that needs to be updated",
      "required": true,
      "type": "string"
    },
    {
      "name": "name",
      "in": "formData",
      "description": "Updated name of the pet",
      "required": false,
      "type": "string"
    },
    {
      "name": "status",
      "in": "formData",
      "description": "Updated status of the pet",
      "required": false,
      "type": "string"
    }
  ],
  "responses": {
    "200": {
      "description": "Pet updated."
    },
    "405": {
      "description": "Invalid input"
    }
  },
  "security": [
    {
      "petstore_auth": [
        "write:pets",
        "read:pets"
      ]
    }
  ]
}

tags:
- pet
summary: Updates a pet in the store with form data
description: ""
operationId: updatePetWithForm
consumes:
- application/x-www-form-urlencoded
produces:
- application/json
- application/xml
parameters:
- name: petId
  in: path
  description: ID of pet that needs to be updated
  required: true
  type: string
- name: name
  in: formData
  description: Updated name of the pet
  required: false
  type: string
- name: status
  in: formData
  description: Updated status of the pet
  required: false
  type: string
responses:
  ‘200‘:
    description: Pet updated.
  ‘405‘:
    description: Invalid input
security:
- petstore_auth:
  - write:pets
  - read:pets

External Documentation Object

Allows referencing an external resource for extended documentation.

Fixed Fields

Patterned Objects

External Documentation Object Example

{
  "description": "Find more info here",
  "url": "https://swagger.io"
}

description: Find more info here
url: https://swagger.io

Parameter Object

Describes a single operation parameter.

A unique parameter is defined by a combination of a name and location.

There are five possible parameter types.

• Path - Used together with Path Templating, where the parameter value is actually part of the operation‘s URL. This does not include the host or base path of the API. For example, in /items/{itemId}, the path parameter is itemId.
• Query - Parameters that are appended to the URL. For example, in /items?id=###, the query parameter is id.
• Header - Custom headers that are expected as part of the request.
• Body - The payload that‘s appended to the HTTP request. Since there can only be one payload, there can only be one body parameter. The name of the body parameter has no effect on the parameter itself and is used for documentation purposes only. Since Form parameters are also in the payload, body and form parameters cannot exist together for the same operation.
• Form - Used to describe the payload of an HTTP request when either application/x-www-form-urlencoded, multipart/form-data or both are used as the content type of the request (in Swagger‘s definition, the consumesproperty of an operation). This is the only parameter type that can be used to send files, thus supporting the filetype. Since form parameters are sent in the payload, they cannot be declared together with a body parameter for the same operation. Form parameters have a different format based on the content-type used (for further details, consult http://www.w3.org/TR/html401/interact/forms.html#h-17.13.4):
  • application/x-www-form-urlencoded - Similar to the format of Query parameters but as a payload. For example, foo=1&bar=swagger - both foo and bar are form parameters. This is normally used for simple parameters that are being transferred.
  • multipart/form-data - each parameter takes a section in the payload with an internal header. For example, for the header Content-Disposition: form-data; name="submit-name" the name of the parameter is submit-name. This type of form parameters is more commonly used for file transfers.

Fixed Fields

If in is "body":

If in is any value other than "body":

Patterned Fields

Parameter Object Examples

Body Parameters

A body parameter with a referenced schema definition (normally for a model definition):

{
  "name": "user",
  "in": "body",
  "description": "user to add to the system",
  "required": true,
  "schema": {
    "$ref": "#/definitions/User"
  }
}

name: user
in: body
description: user to add to the system
required: true
schema:
  $ref: ‘#/definitions/User‘

A body parameter that is an array of string values:

{
  "name": "user",
  "in": "body",
  "description": "user to add to the system",
  "required": true,
  "schema": {
    "type": "array",
    "items": {
      "type": "string"
    }
  }
}

name: user
in: body
description: user to add to the system
required: true
schema:
  type: array
  items:
    type: string

Other Parameters

A header parameter with an array of 64 bit integer numbers:

{
  "name": "token",
  "in": "header",
  "description": "token to be passed as a header",
  "required": true,
  "type": "array",
  "items": {
    "type": "integer",
    "format": "int64"
  },
  "collectionFormat": "csv"
}

name: token
in: header
description: token to be passed as a header
required: true
type: array
items:
  type: integer
  format: int64
collectionFormat: csv

A path parameter of a string value:

{
  "name": "username",
  "in": "path",
  "description": "username to fetch",
  "required": true,
  "type": "string"
}

name: username
in: path
description: username to fetch
required: true
type: string

An optional query parameter of a string value, allowing multiple values by repeating the query parameter:

{
  "name": "id",
  "in": "query",
  "description": "ID of the object to fetch",
  "required": false,
  "type": "array",
  "items": {
    "type": "string"
  },
  "collectionFormat": "multi"
}

name: id
in: query
description: ID of the object to fetch
required: false
type: array
items:
  type: string
collectionFormat: multi

A form data with file type for a file upload:

{
  "name": "avatar",
  "in": "formData",
  "description": "The avatar of the user",
  "required": true,
  "type": "file"
}

name: avatar
in: formData
description: The avatar of the user
required: true
type: file

Items Object

A limited subset of JSON-Schema‘s items object. It is used by parameter definitions that are not located in "body".

Fixed Fields

Patterned Objects

Items Object Examples

Items must be of type string and have the minimum length of 2 characters:

{
    "type": "string",
    "minLength": 2
}

type: string
minLength: 2

An array of arrays, the internal array being of type integer, numbers must be between 0 and 63 (inclusive):

{
    "type": "array",
    "items": {
        "type": "integer",
        "minimum": 0,
        "maximum": 63
    }
}

type: array
items:
  type: integer
  minimum: 0
  maximum: 63

Responses Object

A container for the expected responses of an operation. The container maps a HTTP response code to the expected response. It is not expected from the documentation to necessarily cover all possible HTTP response codes, since they may not be known in advance. However, it is expected from the documentation to cover a successful operation response and any known errors.

The default can be used as the default response object for all HTTP codes that are not covered individually by the specification.

The Responses Object MUST contain at least one response code, and it SHOULD be the response for a successful operation call.

Fixed Fields

Patterned Fields

Responses Object Example

A 200 response for successful operation and a default response for others (implying an error):

{
  "200": {
    "description": "a pet to be returned",
    "schema": {
      "$ref": "#/definitions/Pet"
    }
  },
  "default": {
    "description": "Unexpected error",
    "schema": {
      "$ref": "#/definitions/ErrorModel"
    }
  }
}

‘200‘:
  description: a pet to be returned
  schema:
    $ref: ‘#/definitions/Pet‘
default:
  description: Unexpected error
  schema:
    $ref: ‘#/definitions/ErrorModel‘

Response Object

Describes a single response from an API Operation.

Fixed Fields

Patterned Objects

Response Object Examples

Response of an array of a complex type:

{
  "description": "A complex object array response",
  "schema": {
    "type": "array",
    "items": {
      "$ref": "#/definitions/VeryComplexType"
    }
  }
}

description: A complex object array response
schema:
  type: array
  items:
    $ref: ‘#/definitions/VeryComplexType‘

Response with a string type:

{
  "description": "A simple string response",
  "schema": {
    "type": "string"
  }
}

description: A simple string response
schema:
  type: string

Response with headers:

{
  "description": "A simple string response",
  "schema": {
    "type": "string"
  },
  "headers": {
    "X-Rate-Limit-Limit": {
      "description": "The number of allowed requests in the current period",
      "type": "integer"
    },
    "X-Rate-Limit-Remaining": {
      "description": "The number of remaining requests in the current period",
      "type": "integer"
    },
    "X-Rate-Limit-Reset": {
      "description": "The number of seconds left in the current period",
      "type": "integer"
    }
  }
}

description: A simple string response
schema:
  type: string
headers:
  X-Rate-Limit-Limit:
    description: The number of allowed requests in the current period
    type: integer
  X-Rate-Limit-Remaining:
    description: The number of remaining requests in the current period
    type: integer
  X-Rate-Limit-Reset:
    description: The number of seconds left in the current period
    type: integer

Response with no return value:

{
  "description": "object created"
}

description: object created

Headers Object

Lists the headers that can be sent as part of a response.

Patterned Fields

Headers Object Example

Rate-limit headers:

{
    "X-Rate-Limit-Limit": {
        "description": "The number of allowed requests in the current period",
        "type": "integer"
    },
    "X-Rate-Limit-Remaining": {
        "description": "The number of remaining requests in the current period",
        "type": "integer"
    },
    "X-Rate-Limit-Reset": {
        "description": "The number of seconds left in the current period",
        "type": "integer"
    }
}

X-Rate-Limit-Limit:
  description: The number of allowed requests in the current period
  type: integer
X-Rate-Limit-Remaining:
  description: The number of remaining requests in the current period
  type: integer
X-Rate-Limit-Reset:
  description: The number of seconds left in the current period
  type: integer

Example Object

Allows sharing examples for operation responses.

Patterned Fields

Example Object Example

Example response for application/json mimetype of a Pet data type:

{
  "application/json": {
    "name": "Puma",
    "type": "Dog",
    "color": "Black",
    "gender": "Female",
    "breed": "Mixed"
  }
}

application/json:
  name: Puma
  type: Dog
  color: Black
  gender: Female
  breed: Mixed

Header Object

Patterned Objects

Header Object Example

A simple header with of an integer type:

{
  "description": "The number of allowed requests in the current period",
  "type": "integer"
}

description: The number of allowed requests in the current period
type: integer

Tag Object

Allows adding meta data to a single tag that is used by the Operation Object. It is not mandatory to have a Tag Object per tag used there.

Fixed Fields

Patterned Fields

Tag Object Example

{
    "name": "pet",
    "description": "Pets operations"
}

name: pet
description: Pets operations

Reference Object

A simple object to allow referencing other definitions in the specification. It can be used to reference parameters and responses that are defined at the top level for reuse.

The Reference Object is a JSON Reference that uses a JSON Pointer as its value. For this specification, only canonical dereferencing is supported.

Fixed Fields

Reference Object Example

{
    "$ref": "#/definitions/Pet"
}

$ref: ‘#/definitions/Pet‘

Relative Schema File Example

{
  "$ref": "Pet.json"
}

$ref: ‘Pet.yaml‘

Relative Files With Embedded Schema Example

{
  "$ref": "definitions.json#/Pet"
}

$ref: ‘definitions.yaml#/Pet‘

Schema Object

The Schema Object allows the definition of input and output data types. These types can be objects, but also primitives and arrays. This object is based on the JSON Schema Specification Draft 4 and uses a predefined subset of it. On top of this subset, there are extensions provided by this specification to allow for more complete documentation.

Further information about the properties can be found in JSON Schema Core and JSON Schema Validation. Unless stated otherwise, the property definitions follow the JSON Schema specification as referenced here.

The following properties are taken directly from the JSON Schema definition and follow the same specifications:

• $ref - As a JSON Reference
• format (See Data Type Formats for further details)
• title
• description (GFM syntax can be used for rich text representation)
• default (Unlike JSON Schema, the value MUST conform to the defined type for the Schema Object)
• multipleOf
• maximum
• exclusiveMaximum
• minimum
• exclusiveMinimum
• maxLength
• minLength
• pattern
• maxItems
• minItems
• uniqueItems
• maxProperties
• minProperties
• required
• enum
• type

The following properties are taken from the JSON Schema definition but their definitions were adjusted to the Swagger Specification. Their definition is the same as the one from JSON Schema, only where the original definition references the JSON Schema definition, the Schema Object definition is used instead.

• items
• allOf
• properties
• additionalProperties

Other than the JSON Schema subset fields, the following fields may be used for further schema documentation.

Fixed Fields

Patterned Objects

Composition and Inheritance (Polymorphism)

Swagger allows combining and extending model definitions using the allOf property of JSON Schema, in effect offering model composition. allOf takes in an array of object definitions that are validated independently but together compose a single object.

While composition offers model extensibility, it does not imply a hierarchy between the models. To support polymorphism, Swagger adds the support of the discriminator field. When used, the discriminator will be the name of the property used to decide which schema definition is used to validate the structure of the model. As such, the discriminator field MUST be a required field. The value of the chosen property has to be the friendly name given to the model under the definitionsproperty. As such, inline schema definitions, which do not have a given id, cannot be used in polymorphism.

XML Modeling

The xml property allows extra definitions when translating the JSON definition to XML. The XML Object contains additional information about the available options.

Schema Object Examples

Primitive Sample

Unlike previous versions of Swagger, Schema definitions can be used to describe primitive and arrays as well.

{
    "type": "string",
    "format": "email"
}

type: string
format: email

Simple Model

{
  "type": "object",
  "required": [
    "name"
  ],
  "properties": {
    "name": {
      "type": "string"
    },
    "address": {
      "$ref": "#/definitions/Address"
    },
    "age": {
      "type": "integer",
      "format": "int32",
      "minimum": 0
    }
  }
}

type: object
required:
- name
properties:
  name:
    type: string
  address:
    $ref: ‘#/definitions/Address‘
  age:
    type: integer
    format: int32
    minimum: 0

Model with Map/Dictionary Properties

For a simple string to string mapping:

{
  "type": "object",
  "additionalProperties": {
    "type": "string"
  }
}

type: object
additionalProperties:
  type: string

For a string to model mapping:

{
  "type": "object",
  "additionalProperties": {
    "$ref": "#/definitions/ComplexModel"
  }
}

type: object
additionalProperties:
  $ref: ‘#/definitions/ComplexModel‘

Model with Example

{
  "type": "object",
  "properties": {
    "id": {
      "type": "integer",
      "format": "int64"
    },
    "name": {
      "type": "string"
    }
  },
  "required": [
    "name"
  ],
  "example": {
    "name": "Puma",
    "id": 1
  }
}

type: object
properties:
  id:
    type: integer
    format: int64
  name:
    type: string
required:
- name
example:
  name: Puma
  id: 1

Models with Composition

{
  "definitions": {
    "ErrorModel": {
      "type": "object",
      "required": [
        "message",
        "code"
      ],
      "properties": {
        "message": {
          "type": "string"
        },
        "code": {
          "type": "integer",
          "minimum": 100,
          "maximum": 600
        }
      }
    },
    "ExtendedErrorModel": {
      "allOf": [
        {
          "$ref": "#/definitions/ErrorModel"
        },
        {
          "type": "object",
          "required": [
            "rootCause"
          ],
          "properties": {
            "rootCause": {
              "type": "string"
            }
          }
        }
      ]
    }
  }
}

definitions:
  ErrorModel:
    type: object
    required:
    - message
    - code
    properties:
      message:
        type: string
      code:
        type: integer
        minimum: 100
        maximum: 600
  ExtendedErrorModel:
    allOf:
    - $ref: ‘#/definitions/ErrorModel‘
    - type: object
      required:
      - rootCause
      properties:
        rootCause:
          type: string

Models with Polymorphism Support

{
  "definitions": {
    "Pet": {
      "type": "object",
      "discriminator": "petType",
      "properties": {
        "name": {
          "type": "string"
        },
        "petType": {
          "type": "string"
        }
      },
      "required": [
        "name",
        "petType"
      ]
    },
    "Cat": {
      "description": "A representation of a cat",
      "allOf": [
        {
          "$ref": "#/definitions/Pet"
        },
        {
          "type": "object",
          "properties": {
            "huntingSkill": {
              "type": "string",
              "description": "The measured skill for hunting",
              "default": "lazy",
              "enum": [
                "clueless",
                "lazy",
                "adventurous",
                "aggressive"
              ]
            }
          },
          "required": [
            "huntingSkill"
          ]
        }
      ]
    },
    "Dog": {
      "description": "A representation of a dog",
      "allOf": [
        {
          "$ref": "#/definitions/Pet"
        },
        {
          "type": "object",
          "properties": {
            "packSize": {
              "type": "integer",
              "format": "int32",
              "description": "the size of the pack the dog is from",
              "default": 0,
              "minimum": 0
            }
          },
          "required": [
            "packSize"
          ]
        }
      ]
    }
  }
}

definitions:
  Pet:
    type: object
    discriminator: petType
    properties:
      name:
        type: string
      petType:
        type: string
    required:
    - name
    - petType
  Cat:
    description: A representation of a cat
    allOf:
    - $ref: ‘#/definitions/Pet‘
    - type: object
      properties:
        huntingSkill:
          type: string
          description: The measured skill for hunting
          default: lazy
          enum:
          - clueless
          - lazy
          - adventurous
          - aggressive
      required:
      - huntingSkill
  Dog:
    description: A representation of a dog
    allOf:
    - $ref: ‘#/definitions/Pet‘
    - type: object
      properties:
        packSize:
          type: integer
          format: int32
          description: the size of the pack the dog is from
          default: 0
          minimum: 0
      required:
      - packSize

XML Object

A metadata object that allows for more fine-tuned XML model definitions.

When using arrays, XML element names are not inferred (for singular/plural forms) and the name property should be used to add that information. See examples for expected behavior.

Fixed Fields

Patterned Objects

XML Object Examples

The examples of the XML object definitions are included inside a property definition of a Schema Object with a sample of the XML representation of it.

No XML Element

Basic string property:

{
    "animals": {
        "type": "string"
    }
}

animals:
  type: string

<animals>...</animals>

Basic string array property (wrapped is false by default):

{
    "animals": {
        "type": "array",
        "items": {
            "type": "string"
        }
    }
}

animals:
  type: array
  items:
    type: string

<animals>...</animals>
<animals>...</animals>
<animals>...</animals>

XML Name Replacement

{
  "animals": {
    "type": "string",
    "xml": {
      "name": "animal"
    }
  }
}

animals:
  type: string
  xml:
    name: animal

<animal>...</animal>

XML Attribute, Prefix and Namespace

In this example, a full model definition is shown.

{
  "Person": {
    "type": "object",
    "properties": {
      "id": {
        "type": "integer",
        "format": "int32",
        "xml": {
          "attribute": true
        }
      },
      "name": {
        "type": "string",
        "xml": {
          "namespace": "http://swagger.io/schema/sample",
          "prefix": "sample"
        }
      }
    }
  }
}

Person:
  type: object
  properties:
    id:
      type: integer
      format: int32
      xml:
        attribute: true
    name:
      type: string
      xml:
        namespace: http://swagger.io/schema/sample
        prefix: sample

<Person id="123">
    <sample:name xmlns:sample="http://swagger.io/schema/sample">example</sample:name>
</Person>

XML Arrays

Changing the element names:

{
  "animals": {
    "type": "array",
    "items": {
      "type": "string",
      "xml": {
        "name": "animal"
      }
    }
  }
}

animals:
  type: array
  items:
    type: string
    xml:
      name: animal

<animal>value</animal>
<animal>value</animal>

The external name property has no effect on the XML:

{
  "animals": {
    "type": "array",
    "items": {
      "type": "string",
      "xml": {
        "name": "animal"
      }
    },
    "xml": {
      "name": "aliens"
    }
  }
}

animals:
  type: array
  items:
    type: string
    xml:
      name: animal
  xml:
    name: aliens

<animal>value</animal>
<animal>value</animal>

Even when the array is wrapped, if no name is explicitly defined, the same name will be used both internally and externally:

{
  "animals": {
    "type": "array",
    "items": {
      "type": "string"
    },
    "xml": {
      "wrapped": true
    }
  }
}

animals:
  type: array
  items:
    type: string
  xml:
    wrapped: true

<animals>
  <animals>value</animals>
  <animals>value</animals>
</animals>

To overcome the above example, the following definition can be used:

{
  "animals": {
    "type": "array",
    "items": {
      "type": "string",
      "xml": {
        "name": "animal"
      }
    },
    "xml": {
      "wrapped": true
    }
  }
}

animals:
  type: array
  items:
    type: string
    xml:
      name: animal
  xml:
    wrapped: true

<animals>
  <animal>value</animal>
  <animal>value</animal>
</animals>

Affecting both internal and external names:

{
  "animals": {
    "type": "array",
    "items": {
      "type": "string",
      "xml": {
        "name": "animal"
      }
    },
    "xml": {
      "name": "aliens",
      "wrapped": true
    }
  }
}

animals:
  type: array
  items:
    type: string
    xml:
      name: animal
  xml:
    name: aliens
    wrapped: true

<aliens>
  <animal>value</animal>
  <animal>value</animal>
</aliens>

If we change the external element but not the internal ones:

{
  "animals": {
    "type": "array",
    "items": {
      "type": "string"
    },
    "xml": {
      "name": "aliens",
      "wrapped": true
    }
  }
}

animals:
  type: array
  items:
    type: string
  xml:
    name: aliens
    wrapped: true

<aliens>
  <aliens>value</aliens>
  <aliens>value</aliens>
</aliens>

Definitions Object

An object to hold data types that can be consumed and produced by operations. These data types can be primitives, arrays or models.

Patterned Fields

Definitions Object Example

{
  "Category": {
    "type": "object",
    "properties": {
      "id": {
        "type": "integer",
        "format": "int64"
      },
      "name": {
        "type": "string"
      }
    }
  },
  "Tag": {
    "type": "object",
    "properties": {
      "id": {
        "type": "integer",
        "format": "int64"
      },
      "name": {
        "type": "string"
      }
    }
  }
}

Category:
  type: object
  properties:
    id:
      type: integer
      format: int64
    name:
      type: string
Tag:
  type: object
  properties:
    id:
      type: integer
      format: int64
    name:
      type: string

Parameters Definitions Object

An object to hold parameters to be reused across operations. Parameter definitions can be referenced to the ones defined here.

This does not define global operation parameters.

Patterned Fields

Parameters Definition Object Example

{
  "skipParam": {
    "name": "skip",
    "in": "query",
    "description": "number of items to skip",
    "required": true,
    "type": "integer",
    "format": "int32"
  },
  "limitParam": {
    "name": "limit",
    "in": "query",
    "description": "max records to return",
    "required": true,
    "type": "integer",
    "format": "int32"
  }
}

skipParam:
  name: skip
  in: query
  description: number of items to skip
  required: true
  type: integer
  format: int32
limitParam:
  name: limit
  in: query
  description: max records to return
  required: true
  type: integer
  format: int32

Responses Definitions Object

An object to hold responses to be reused across operations. Response definitions can be referenced to the ones defined here.

This does not define global operation responses.

Patterned Fields

Responses Definitions Object Example

{
  "NotFound": {
    "description": "Entity not found."
  },
  "IllegalInput": {
    "description": "Illegal input for operation."
  },
  "GeneralError": {
    "description": "General Error",
    "schema": {
        "$ref": "#/definitions/GeneralError"
    }
  }
}

NotFound:
  description: Entity not found.
IllegalInput:
  description: Illegal input for operation.
GeneralError:
  description: General Error
  schema:
    $ref: ‘#/definitions/GeneralError‘

Security Definitions Object

A declaration of the security schemes available to be used in the specification. This does not enforce the security schemes on the operations and only serves to provide the relevant details for each scheme.

Patterned Fields

Security Definitions Object Example

{
  "api_key": {
    "type": "apiKey",
    "name": "api_key",
    "in": "header"
  },
  "petstore_auth": {
    "type": "oauth2",
    "authorizationUrl": "http://swagger.io/api/oauth/dialog",
    "flow": "implicit",
    "scopes": {
      "write:pets": "modify pets in your account",
      "read:pets": "read your pets"
    }
  }
}

api_key:
  type: apiKey
  name: api_key
  in: header
petstore_auth:
  type: oauth2
  authorizationUrl: http://swagger.io/api/oauth/dialog
  flow: implicit
  scopes:
    write:pets: modify pets in your account
    read:pets: read your pets

Security Scheme Object

Allows the definition of a security scheme that can be used by the operations. Supported schemes are basic authentication, an API key (either as a header or as a query parameter) and OAuth2‘s common flows (implicit, password, application and access code).

Fixed Fields

Patterned Fields

Security Scheme Object Example

Basic Authentication Sample

{
  "type": "basic"
}

type: basic

API Key Sample

{
  "type": "apiKey",
  "name": "api_key",
  "in": "header"
}

type: apiKey
name: api_key
in: header

Implicit OAuth2 Sample

{
  "type": "oauth2",
  "authorizationUrl": "http://swagger.io/api/oauth/dialog",
  "flow": "implicit",
  "scopes": {
    "write:pets": "modify pets in your account",
    "read:pets": "read your pets"
  }
}

type: oauth2
authorizationUrl: http://swagger.io/api/oauth/dialog
flow: implicit
scopes:
  write:pets: modify pets in your account
  read:pets: read your pets

Scopes Object

Lists the available scopes for an OAuth2 security scheme.

Patterned Fields

Patterned Objects

Scopes Object Example

{
  "write:pets": "modify pets in your account",
  "read:pets": "read your pets"
}

write:pets: modify pets in your account
read:pets: read your pets

Security Requirement Object

Lists the required security schemes to execute this operation. The object can have multiple security schemes declared in it which are all required (that is, there is a logical AND between the schemes).

The name used for each property MUST correspond to a security scheme declared in the Security Definitions.

Patterned Fields

Security Requirement Object Examples

Non-OAuth2 Security Requirement

{
  "api_key": []
}

api_key: []

OAuth2 Security Requirement

{
  "petstore_auth": [
    "write:pets",
    "read:pets"
  ]
}

petstore_auth:
- write:pets
- read:pets

Specification Extensions

While the Swagger Specification tries to accommodate most use cases, additional data can be added to extend the specification at certain points.

The extensions properties are always prefixed by "x-" and can have any valid JSON format value.

The extensions may or may not be supported by the available tooling, but those may be extended as well to add requested support (if tools are internal or open-sourced).

Security Filtering

Some objects in the Swagger specification may be declared and remain empty, or completely be removed, even though they are inherently the core of the API documentation.

The reasoning behind it is to allow an additional layer of access control over the documentation itself. While not part of the specification itself, certain libraries may choose to allow access to parts of the documentation based on some form of authentication/authorization.

Two examples for this:

1. The Paths Object may be empty. It may be counterintuitive, but this may tell the viewer that they got to the right place, but can‘t access any documentation. They‘d still have access to the Info Object which may contain additional information regarding authentication.
2. The Path Item Object may be empty. In this case, the viewer will be aware that the path exists, but will not be able to see any of its operations or parameters. This is different than hiding the path itself from the Paths Object so the user will not be aware of its existence. This allows the documentation provider a finer control over what the viewer can see.

View Source on GitHub

SWAGGER SPECIFICATION