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
Version |
Date |
Notes |
2.0 |
2014-09-08 |
Release of Swagger 2.0 |
1.2 |
2014-03-14 |
Initial release of the formal document. |
1.1 |
2012-08-22 |
Release of Swagger 1.1 |
1.0 |
2011-08-10 |
First release of the Swagger Specification |
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
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 Schema definitions.
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:
Common Name |
type |
format |
Comments |
integer |
integer |
int32 |
signed 32 bits |
long |
integer |
int64 |
signed 64 bits |
float |
number |
float |
|
double |
number |
double |
|
string |
string |
|
|
byte |
string |
byte |
base64 encoded characters |
binary |
string |
binary |
any sequence of octets |
boolean |
boolean |
|
|
date |
string |
date |
As defined by full-date - RFC3339 |
dateTime |
string |
date-time |
As defined by date-time - RFC3339 |
password |
string |
password |
Used to hint UIs the input needs to be obscured. |
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
Field Name |
Type |
Description |
swagger |
string |
Required. Specifies the Swagger Specification version being used. It can be used by the Swagger UI and other clients to interpret the API listing. The value MUST be "2.0" . |
info |
Info Object |
Required. Provides metadata about the API. The metadata can be used by the clients if needed. |
host |
string |
The host (name or ip) serving the API. This MUST be the host only and does not include the scheme nor sub-paths. It MAY include a port. If the host is not included, the host serving the documentation is to be used (including the port). The host does not support path templating. |
basePath |
string |
The base path on which the API is served, which is relative to the host . If it is not included, the API is served directly under the host . The value MUST start with a leading slash (/ ). The basePath does not support path templating. |
schemes |
[string ] |
The transfer protocol of the API. Values MUST be from the list: "http" , "https" , "ws" , "wss" . If the schemes is not included, the default scheme to be used is the one used to access the Swagger definition itself. |
consumes |
[string ] |
A list of MIME types the APIs can consume. This is global to all APIs but can be overridden on specific API calls. Value MUST be as described under Mime Types. |
produces |
[string ] |
A list of MIME types the APIs can produce. This is global to all APIs but can be overridden on specific API calls. Value MUST be as described under Mime Types. |
paths |
Paths Object |
Required. The available paths and operations for the API. |
definitions |
Definitions Object |
An object to hold data types produced and consumed by operations. |
parameters |
Parameters Definitions Object |
An object to hold parameters that can be used across operations. This property does not define global parameters for all operations. |
responses |
Responses Definitions Object |
An object to hold responses that can be used across operations. This property does not define global responses for all operations. |
securityDefinitions |
Security Definitions Object |
Security scheme definitions that can be used across the specification. |
security |
[Security Requirement Object] |
A declaration of which security schemes are applied for the API as a whole. The list of values describes alternative security schemes that can be used (that is, there is a logical OR between the security requirements). Individual operations can override this definition. |
tags |
[Tag Object] |
A list of tags used by the specification with additional metadata. The order of the tags can be used to reflect on their order by the parsing tools. Not all tags that are used by the Operation Object must be declared. The tags that are not declared may be organized randomly or based on the tools' logic. Each tag name in the list MUST be unique. |
externalDocs |
External Documentation Object |
Additional external documentation. |
Patterned Objects
Field Pattern |
Type |
Description |
^x- |
Any |
Allows extensions to the Swagger Schema. The field name MUST begin with x- , for example, x-internal-id . The value can be null , a primitive, an array or an object. See Vendor Extensions for further details. |
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
Field Name |
Type |
Description |
title |
string |
Required. The title of the application. |
description |
string |
A short description of the application. GFM syntax can be used for rich text representation. |
termsOfService |
string |
The Terms of Service for the API. |
contact |
Contact Object |
The contact information for the exposed API. |
license |
License Object |
The license information for the exposed API. |
version |
string |
Required Provides the version of the application API (not to be confused with the specification version). |
Patterned Objects
Field Pattern |
Type |
Description |
^x- |
Any |
Allows extensions to the Swagger Schema. The field name MUST begin with x- , for example, x-internal-id . The value can be null , a primitive, an array or an object. See Vendor Extensions for further details. |
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": "[email protected]"
},
"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: [email protected]
license:
name: Apache 2.0
url: http://www.apache.org/licenses/LICENSE-2.0.html
version: 1.0.1
Contact information for the exposed API.
Fixed Fields
Field Name |
Type |
Description |
name |
string |
The identifying name of the contact person/organization. |
url |
string |
The URL pointing to the contact information. MUST be in the format of a URL. |
email |
string |
The email address of the contact person/organization. MUST be in the format of an email address. |
Patterned Objects
Field Pattern |
Type |
Description |
^x- |
Any |
Allows extensions to the Swagger Schema. The field name MUST begin with x- , for example, x-internal-id . The value can be null , a primitive, an array or an object. See Vendor Extensions for further details. |
{
"name": "API Support",
"url": "http://www.swagger.io/support",
"email": "[email protected]"
}
name: API Support
url: http://www.swagger.io/support
email: [email protected]
License Object
License information for the exposed API.
Fixed Fields
Field Name |
Type |
Description |
name |
string |
Required. The license name used for the API. |
url |
string |
A URL to the license used for the API. MUST be in the format of a URL. |
Patterned Objects
Field Pattern |
Type |
Description |
^x- |
Any |
Allows extensions to the Swagger Schema. The field name MUST begin with x- , for example, x-internal-id . The value can be null , a primitive, an array or an object. See Vendor Extensions for further details. |
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
Field Pattern |
Type |
Description |
/{path} |
Path Item Object |
A relative path to an individual endpoint. The field name MUST begin with a slash. The path is appended to the basePath in order to construct the full URL. Path templating is allowed. |
^x- |
Any |
Allows extensions to the Swagger Schema. The field name MUST begin with x- , for example, x-internal-id . The value can be null , a primitive, an array or an object. See Vendor Extensions for further details. |
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
Field Name |
Type |
Description |
$ref |
string |
Allows for an external definition of this path item. The referenced structure MUST be in the format of a Path Item Object. If there are conflicts between the referenced definition and this Path Item's definition, the behavior is undefined. |
get |
Operation Object |
A definition of a GET operation on this path. |
put |
Operation Object |
A definition of a PUT operation on this path. |
post |
Operation Object |
A definition of a POST operation on this path. |
delete |
Operation Object |
A definition of a DELETE operation on this path. |
options |
Operation Object |
A definition of a OPTIONS operation on this path. |
head |
Operation Object |
A definition of a HEAD operation on this path. |
patch |
Operation Object |
A definition of a PATCH operation on this path. |
parameters |
[Parameter Object | Reference Object] |
A list of parameters that are applicable for all the operations described under this path. These parameters can be overridden at the operation level, but cannot be removed there. The list MUST NOT include duplicated parameters. A unique parameter is defined by a combination of a name and location. The list can use the Reference Object to link to parameters that are defined at the Swagger Object's parameters. There can be one "body" parameter at most. |
Patterned Fields
Field Pattern |
Type |
Description |
^x- |
Any |
Allows extensions to the Swagger Schema. The field name MUST begin with x- , for example, x-internal-id . The value can be null , a primitive, an array or an object. See Vendor Extensions for further details. |
Path Item Object Example
{
"get": {
"description": "Returns pets based on ID",
"summary": "Find pets by ID",
"operationId": "getPetsById",
"produces": [
"application/json",
"text/html"
],
"responses": {
"200": {
"description": "pet response",
"schema": {
"type": "array",
"items": {
"$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
Field Name |
Type |
Description |
tags |
[string ] |
A list of tags for API documentation control. Tags can be used for logical grouping of operations by resources or any other qualifier. |
summary |
string |
A short summary of what the operation does. For maximum readability in the swagger-ui, this field SHOULD be less than 120 characters. |
description |
string |
A verbose explanation of the operation behavior. GFM syntax can be used for rich text representation. |
externalDocs |
External Documentation Object |
Additional external documentation for this operation. |
operationId |
string |
Unique string used to identify the operation. The id MUST be unique among all operations described in the API. Tools and libraries MAY use the operationId to uniquely identify an operation, therefore, it is recommended to follow common programming naming conventions. |
consumes |
[string ] |
A list of MIME types the operation can consume. This overrides the consumes definition at the Swagger Object. An empty value MAY be used to clear the global definition. Value MUST be as described under Mime Types. |
produces |
[string ] |
A list of MIME types the operation can produce. This overrides the produces definition at the Swagger Object. An empty value MAY be used to clear the global definition. Value MUST be as described under Mime Types. |
parameters |
[Parameter Object | Reference Object] |
A list of parameters that are applicable for this operation. If a parameter is already defined at the Path Item, the new definition will override it, but can never remove it. The list MUST NOT include duplicated parameters. A unique parameter is defined by a combination of a name and location. The list can use the Reference Object to link to parameters that are defined at the Swagger Object's parameters. There can be one "body" parameter at most. |
responses |
Responses Object |
Required. The list of possible responses as they are returned from executing this operation. |
schemes |
[string ] |
The transfer protocol for the operation. Values MUST be from the list: "http" , "https" , "ws" , "wss" . The value overrides the Swagger Object schemes definition. |
deprecated |
boolean |
Declares this operation to be deprecated. Usage of the declared operation should be refrained. Default value is false . |
security |
[Security Requirement Object] |
A declaration of which security schemes are applied for this operation. The list of values describes alternative security schemes that can be used (that is, there is a logical OR between the security requirements). This definition overrides any declared top-level security . To remove a top-level security declaration, an empty array can be used. |
Patterned Objects
Field Pattern |
Type |
Description |
^x- |
Any |
Allows extensions to the Swagger Schema. The field name MUST begin with x- , for example, x-internal-id . The value can be null , a primitive, an array or an object. See Vendor Extensions for further details. |
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
Field Name |
Type |
Description |
description |
string |
A short description of the target documentation. GFM syntax can be used for rich text representation. |
url |
string |
Required. The URL for the target documentation. Value MUST be in the format of a URL. |
Patterned Objects
Field Pattern |
Type |
Description |
^x- |
Any |
Allows extensions to the Swagger Schema. The field name MUST begin with x- , for example, x-internal-id . The value can be null , a primitive, an array or an object. See Vendor Extensions for further details. |
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 consumes
property of an operation). This is the only parameter type that can be used to send files, thus supporting the file
type. 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
Field Name |
Type |
Description |
name |
string |
Required. The name of the parameter. Parameter names are case sensitive. - If
in is "path" , the name field MUST correspond to the associated path segment from the path field in the Paths Object. See Path Templating for further information. - For all other cases, the
name corresponds to the parameter name used based on the in property.
|
in |
string |
Required. The location of the parameter. Possible values are "query", "header", "path", "formData" or "body". |
description |
string |
A brief description of the parameter. This could contain examples of use. GFM syntax can be used for rich text representation. |
required |
boolean |
Determines whether this parameter is mandatory. If the parameter is in "path", this property is required and its value MUST be true . Otherwise, the property MAY be included and its default value is false . |
If in
is "body"
:
Field Name |
Type |
Description |
schema |
Schema Object |
Required. The schema defining the type used for the body parameter. |
If in
is any value other than "body"
:
Field Name |
Type |
Description |
type |
string |
Required. The type of the parameter. Since the parameter is not located at the request body, it is limited to simple types (that is, not an object). The value MUST be one of "string" , "number" , "integer" , "boolean" , "array" or "file" . If type is "file" , the consumes MUST be either "multipart/form-data" , " application/x-www-form-urlencoded" or both and the parameter MUST be in "formData" . |
format |
string |
The extending format for the previously mentioned type . See Data Type Formats for further details. |
allowEmptyValue |
boolean |
Sets the ability to pass empty-valued parameters. This is valid only for either query or formData parameters and allows you to send a parameter with a name only or an empty value. Default value is false . |
items |
Items Object |
Required if type is "array". Describes the type of items in the array. |
collectionFormat |
string |
Determines the format of the array if type array is used. Possible values are: csv - comma separated values foo,bar . ssv - space separated values foo bar . tsv - tab separated values foo\tbar . pipes - pipe separated values foo|bar . multi - corresponds to multiple parameter instances instead of multiple values for a single instance foo=bar&foo=baz . This is valid only for parameters in "query" or "formData". Default value is csv . |
default |
* |
Declares the value of the parameter that the server will use if none is provided, for example a "count" to control the number of results per page might default to 100 if not supplied by the client in the request. (Note: "default" has no meaning for required parameters.) See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-6.2. Unlike JSON Schema this value MUST conform to the defined type for this parameter. |
maximum |
number |
See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.1.2. |
exclusiveMaximum |
boolean |
See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.1.2. |
minimum |
number |
See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.1.3. |
exclusiveMinimum |
boolean |
See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.1.3. |
maxLength |
integer |
See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.2.1. |
minLength |
integer |
See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.2.2. |
pattern |
string |
See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.2.3. |
maxItems |
integer |
See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.3.2. |
minItems |
integer |
See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.3.3. |
uniqueItems |
boolean |
See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.3.4. |
enum |
[*] |
See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.5.1. |
multipleOf |
number |
See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.1.1. |
Patterned Fields
Field Pattern |
Type |
Description |
^x- |
Any |
Allows extensions to the Swagger Schema. The field name MUST begin with x- , for example, x-internal-id . The value can be null , a primitive, an array or an object. See Vendor Extensions for further details. |
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
Field Pattern |
Type |
Description |
^x- |
Any |
Allows extensions to the Swagger Schema. The field name MUST begin with x- , for example, x-internal-id . The value can be null , a primitive, an array or an object. See Vendor Extensions for further details. |
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:
$ref: '#/definitions/ErrorModel'
Response Object
Describes a single response from an API Operation.
Fixed Fields
Field Name |
Type |
Description |
description |
string |
Required. A short description of the response. GFM syntax can be used for rich text representation. |
schema |
Schema Object |
A definition of the response structure. It can be a primitive, an array or an object. If this field does not exist, it means no content is returned as part of the response. As an extension to the Schema Object, its root type value may also be "file" . This SHOULD be accompanied by a relevant produces mime-type. |
headers |
Headers Object |
A list of headers that are sent with the response. |
examples |
Example Object |
An example of the response message. |
Patterned Objects
Field Pattern |
Type |
Description |
^x- |
Any |
Allows extensions to the Swagger Schema. The field name MUST begin with x- , for example, x-internal-id . The value can be null , a primitive, an array or an object. See Vendor Extensions for further details. |
Response Object Examples
Response of an array of a complex type:
{
"description": "A complex object array response",
"schema": {
"type": "array",
"items": {
"$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
Lists the headers that can be sent as part of a response.
Patterned Fields
Field Pattern |
Type |
Description |
{name} |
Header Object |
The name of the property corresponds to the name of the header. The value describes the type of the header. |
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
Field Pattern |
Type |
Description |
{mime type} |
Any |
The name of the property MUST be one of the Operation produces values (either implicit or inherited). The value SHOULD be an example of what such a response would look like. |
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
Patterned Objects
Field Pattern |
Type |
Description |
^x- |
Any |
Allows extensions to the Swagger Schema. The field name MUST begin with x- , for example, x-internal-id . The value can be null , a primitive, an array or an object. See Vendor Extensions for further details. |
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
Field Name |
Type |
Description |
name |
string |
Required. The name of the tag. |
description |
string |
A short description for the tag. GFM syntax can be used for rich text representation. |
externalDocs |
External Documentation Object |
Additional external documentation for this tag. |
Patterned Fields
Field Pattern |
Type |
Description |
^x- |
Any |
Allows extensions to the Swagger Schema. The field name MUST begin with x- , for example, x-internal-id . The value can be null , a primitive, an array or an object. See Vendor Extensions for further details. |
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
Field Name |
Type |
Description |
$ref |
string |
Required. The reference string. |
Reference Object Example
{
"$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
Field Name |
Type |
Description |
discriminator |
string |
Adds support for polymorphism. The discriminator is the schema property name that is used to differentiate between other schema that inherit this schema. The property name used MUST be defined at this schema and it MUST be in the required property list. When used, the value MUST be the name of this schema or any schema that inherits it. |
readOnly |
boolean |
Relevant only for Schema "properties" definitions. Declares the property as "read only". This means that it MAY be sent as part of a response but MUST NOT be sent as part of the request. Properties marked as readOnly being true SHOULD NOT be in the required list of the defined schema. Default value is false . |
xml |
XML Object |
This MAY be used only on properties schemas. It has no effect on root schemas. Adds Additional metadata to describe the XML representation format of this property. |
externalDocs |
External Documentation Object |
Additional external documentation for this schema. |
example |
Any |
A free-form property to include an example of an instance for this schema. |
Patterned Objects
Field Pattern |
Type |
Description |
^x- |
Any |
Allows extensions to the Swagger Schema. The field name MUST begin with x- , for example, x-internal-id . The value can be null , a primitive, an array or an object. See Vendor Extensions for further details. |
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 definitions
property. 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
Field Name |
Type |
Description |
name |
string |
Replaces the name of the element/attribute used for the described schema property. When defined within the Items Object (items ), it will affect the name of the individual XML elements within the list. When defined alongside type being array (outside the items ), it will affect the wrapping element and only if wrapped is true . If wrapped is false , it will be ignored. |
namespace |
string |
The URL of the namespace definition. Value SHOULD be in the form of a URL. |
prefix |
string |
The prefix to be used for the name. |
attribute |
boolean |
Declares whether the property definition translates to an attribute instead of an element. Default value is false . |
wrapped |
boolean |
MAY be used only for an array definition. Signifies whether the array is wrapped (for example, <books><book/><book/></books> ) or unwrapped (<book/><book/> ). Default value is false . The definition takes effect only when defined alongside type being array (outside the items ). |
Patterned Objects
Field Pattern |
Type |
Description |
^x- |
Any |
Allows extensions to the Swagger Schema. The field name MUST begin with x- , for example, x-internal-id . The value can be null , a primitive, an array or an object. See Vendor Extensions for further details. |
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
Field Pattern |
Type |
Description |
{name} |
Schema Object |
A single definition, mapping a "name" to the schema it defines. |
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
Field Pattern |
Type |
Description |
{name} |
Parameter Object |
A single parameter definition, mapping a "name" to the parameter it defines. |
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
Field Pattern |
Type |
Description |
{name} |
Response Object |
A single response definition, mapping a "name" to the response it defines. |
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
Field Pattern |
Type |
Description |
{name} |
Security Scheme Object |
A single security scheme definition, mapping a "name" to the scheme it defines. |
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
Field Name |
Type |
Validity |
Description |
type |
string |
Any |
Required. The type of the security scheme. Valid values are "basic" , "apiKey" or "oauth2" . |
description |
string |
Any |
A short description for security scheme. |
name |
string |
apiKey |
Required. The name of the header or query parameter to be used. |
in |
string |
apiKey |
Required The location of the API key. Valid values are "query" or "header" . |
flow |
string |
oauth2 |
Required. The flow used by the OAuth2 security scheme. Valid values are "implicit" , "password" , "application" or "accessCode" . |
authorizationUrl |
string |
oauth2 ("implicit" , "accessCode" ) |
Required. The authorization URL to be used for this flow. This SHOULD be in the form of a URL. |
tokenUrl |
string |
oauth2 ("password" , "application" , "accessCode" ) |
Required. The token URL to be used for this flow. This SHOULD be in the form of a URL. |
scopes |
Scopes Object |
oauth2 |
Required. The available scopes for the OAuth2 security scheme. |
Patterned Fields
Field Name |
Type |
Description |
^x- |
Any |
Allows extensions to the Swagger Schema. The field name MUST begin with x- , for example, x-internal-id . The value can be null , a primitive, an array or an object. See Vendor Extensions for further details. |
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
Field Pattern |
Type |
Description |
{name} |
string |
Maps between a name of a scope to a short description of it (as the value of the property). |
Patterned Objects
Field Pattern |
Type |
Description |
^x- |
Any |
Allows extensions to the Swagger Schema. The field name MUST begin with x- , for example, x-internal-id . The value can be null , a primitive, an array or an object. See Vendor Extensions for further details. |
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
Field Pattern |
Type |
Description |
{name} |
[string ] |
Each name must correspond to a security scheme which is declared in the Security Definitions. If the security scheme is of type "oauth2" , then the value is a list of scope names required for the execution. For other security scheme types, the array MUST be empty. |
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:
- 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.
- 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.