# Redoc vendor extensions
You can use the following [vendor extensions](https://redocly.com/docs/openapi-visual-reference/specification-extensions/) with Redoc.
- [Redoc vendor extensions](#redoc-vendor-extensions)
- [Swagger Object](#swagger-object)
- [x-servers](#x-servers)
- [x-tagGroups](#x-taggroups)
- [How to use with Redoc](#how-to-use-with-redoc)
- [Tag Group Object](#tag-group-object)
- [Fixed fields](#fixed-fields)
- [x-tagGroups example](#x-taggroups-example)
- [x-ignoredHeaderParameters](#x-ignoredheaderparameters)
- [How to use with Redoc](#how-to-use-with-redoc-1)
- [x-ignoredHeaderParameters example](#x-ignoredheaderparameters-example)
- [Info Object](#info-object)
- [x-logo](#x-logo)
- [How to use with Redoc](#how-to-use-with-redoc-2)
- [Logo Object](#logo-object)
- [Fixed fields](#fixed-fields-1)
- [x-logo example](#x-logo-example)
- [Tag Object](#tag-object)
- [x-traitTag](#x-traittag)
- [How to use with Redoc](#how-to-use-with-redoc-3)
- [x-traitTag example](#x-traittag-example)
- [x-displayName](#x-displayname)
- [Operation Object vendor extensions](#operation-object-vendor-extensions)
- [x-codeSamples](#x-codesamples)
- [How to use with Redoc](#how-to-use-with-redoc-4)
- [Code Sample Object](#code-sample-object)
- [Fixed fields](#fixed-fields-2)
- [Code Sample Object example](#code-sample-object-example)
- [Parameter Object](#parameter-object)
- [x-examples](#x-examples)
- [How to use with Redoc](#how-to-use-with-redoc-5)
- [Response Object vendor extensions](#response-object-vendor-extensions)
- [x-summary](#x-summary)
- [How to use with Redoc](#how-to-use-with-redoc-6)
- [Schema Object](#schema-object)
- [x-nullable](#x-nullable)
- [How to use with Redoc](#how-to-use-with-redoc-7)
- [x-extendedDiscriminator](#x-extendeddiscriminator)
- [How to use with Redoc](#how-to-use-with-redoc-8)
- [x-extendedDiscriminator example](#x-extendeddiscriminator-example)
- [x-additionalPropertiesName](#x-additionalpropertiesname)
- [How to use with Redoc](#how-to-use-with-redoc-9)
- [x-additionalPropertiesName example](#x-additionalpropertiesname-example)
- [x-explicitMappingOnly](#x-explicitmappingonly)
- [How to use with Redoc](#how-to-use-with-redoc-10)
- [x-explicitMappingOnly example](#x-explicitmappingonly-example)
### Swagger Object
Extends the OpenAPI root [OpenAPI Object](https://redocly.com/docs/openapi-visual-reference/openapi/)
#### x-servers
Backported from OpenAPI 3.0 [`servers`](https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.0.md#serverObject). Currently doesn't support templates.
#### x-tagGroups
| Field Name | Type | Description |
| :------------- | :-----------: | :---------- |
| x-tagGroups | [ [Tag Group Object](#tag-group-object) ] | A list of tag groups |
###### How to use with Redoc
`x-tagGroups` is used to group tags in the side menu.
Before you use `x-tagGroups`, make sure you **add all tags to a group**, since a tag that is not in a group, **is not displayed** at all!
#### Tag Group Object
Information about tags group
###### Fixed fields
| Field Name | Type | Description |
| :---------- | :--------: | :---------- |
| name | string | The group name |
| tags | [ string ] | List of tags to include in this group
###### x-tagGroups example
json
```json
{
"x-tagGroups": [
{
"name": "User Management",
"tags": ["Users", "API keys", "Admin"]
},
{
"name": "Statistics",
"tags": ["Main Stats", "Secondary Stats"]
}
]
}
```
yaml
```yaml
x-tagGroups:
- name: User Management
tags:
- Users
- API keys
- Admin
- name: Statistics
tags:
- Main Stats
- Secondary Stats
```
#### x-ignoredHeaderParameters
| Field Name | Type | Description |
| :-------------------------- | :-----------: | :---------- |
| x-ignoredHeaderParameters | [ string ] | A list of ignored headers |
###### How to use with Redoc
Use `x-ignoredHeaderParameters` to specify header parameter names which are ignored by Redoc.
###### x-ignoredHeaderParameters example
```yaml
swagger: '2.0'
info:
...
tags: [...]
x-ignoredHeaderParameters:
- Accept
- User-Agent
- X-Test-Header
```
### Info Object
Extends the OpenAPI [Info Object](https://redocly.com/docs/openapi-visual-reference/info/)
#### x-logo
| Field Name | Type | Description |
| :------------- | :-----------: | :---------- |
| x-logo | [Logo Object](#logo-object) | The information about API logo |
###### How to use with Redoc
`x-logo` is used to specify API logo. The corresponding image is displayed just above the side-menu.
#### Logo Object
The information about API logo
###### Fixed fields
| Field Name | Type | Description |
| :-------------- | :------: | :---------- |
| url | string | The URL pointing to the spec logo. MUST be in the format of a URL. It SHOULD be an absolute URL so your API definition is usable from any location
| backgroundColor | string | background color to be used. MUST be RGB color in [hexadecimal format] (https://en.wikipedia.org/wiki/Web_colors#Hex_triplet)
| altText | string | Text to use for alt tag on the logo. Defaults to 'logo' if nothing is provided.
| href | string | The URL pointing to the contact page. Default to 'info.contact.url' field of the OAS.
###### x-logo example
json
```json
{
"info": {
"version": "1.0.0",
"title": "Swagger Petstore",
"x-logo": {
"url": "https://redocly.github.io/redoc/petstore-logo.png",
"backgroundColor": "#FFFFFF",
"altText": "Petstore logo"
}
}
}
```
yaml
```yaml
info:
version: "1.0.0"
title: "Swagger Petstore"
x-logo:
url: "https://redocly.github.io/redoc/petstore-logo.png"
backgroundColor: "#FFFFFF"
altText: "Petstore logo"
```
### Tag Object
Extends the OpenAPI [Tag Object](https://redocly.com/docs/openapi-visual-reference/tags/)
#### x-traitTag
| Field Name | Type | Description |
| :------------- | :------: | :---------- |
| x-traitTag | boolean | In Swagger two operations can have multiple tags. This property distinguishes between tags that are used to group operations (default) from tags that are used to mark operation with certain trait (`true` value) |
###### How to use with Redoc
Tags that have `x-traitTag` set to `true` are listed in the side-menu but don't have any subitems (operations). It also renders the `description` tag.
This is useful for handling out common things like Pagination, Rate-Limits, etc.
###### x-traitTag example
json
```json
{
"name": "Pagination",
"description": "Pagination description (can use markdown syntax)",
"x-traitTag": true
}
```
yaml
```yaml
name: Pagination
description: Pagination description (can use markdown syntax)
x-traitTag: true
```
#### x-displayName
| Field Name | Type | Description |
| :------------- | :------: | :---------- |
| x-displayName | string | Defines the text that is used for this tag in the menu and in section headings |
### Operation Object vendor extensions
Extends the OpenAPI [Operation Object](https://redocly.com/docs/openapi-visual-reference/operation/)
#### x-codeSamples
| Field Name | Type | Description |
| :------------- | :------: | :---------- |
| x-codeSamples | [ [Code Sample Object](#code-sample-object) ] | A list of code samples associated with operation |
###### How to use with Redoc
`x-codeSamples` are rendered on the right panel in Redoc.
#### Code Sample Object
Operation code sample
###### Fixed fields
| Field Name | Type | Description |
| :---------- | :------: | :----------- |
| lang | string | Code sample language. Value should be one of the following [list](https://github.com/github/linguist/blob/master/lib/linguist/popular.yml) |
| label | string? | Code sample label, for example `Node` or `Python2.7`, _optional_, `lang` is used by default |
| source | string | Code sample source code |
###### Code Sample Object example
json
```json
{
"lang": "JavaScript",
"source": "console.log('Hello World');"
}
```
yaml
```yaml
lang: JavaScript
source: console.log('Hello World');
```
### Parameter Object
Extends the OpenAPI [Parameter Object](https://redocly.com/docs/openapi-visual-reference/parameter/)
#### x-examples
| Field Name | Type | Description |
| :------------- | :------: | :---------- |
| x-examples | [Example Object](https://redocly.com/docs/openapi-visual-reference/example/) | Object that contains examples for the request. Applies when `in` is `body` and mime-type is `application/json` |
###### How to use with Redoc
`x-examples` are rendered in the JSON tab on the right panel in Redoc.
### Response Object vendor extensions
Extends the OpenAPI [Response Object](https://redocly.com/docs/openapi-visual-reference/response/).
#### x-summary
| Field Name | Type | Description |
| :------------- | :------: | :---------- |
| x-summary | string | a short summary of the response |
###### How to use with Redoc
If specified, you can use `x-summary` as the response button text, with description rendered under the button.
### Schema Object
Extends the OpenAPI [Schema Object](https://redocly.com/docs/openapi-visual-reference/schemas/)
#### x-nullable
| Field Name | Type | Description |
| :------------- | :------: | :---------- |
| x-nullable | boolean | marks schema as a nullable |
###### How to use with Redoc
Schemas marked as `x-nullable` are marked in Redoc with the label Nullable.
#### x-extendedDiscriminator
**ATTENTION**: This is a Redoc-specific vendor extension, and is not supported by other tools.
| Field Name | Type | Description |
| :------------- | :------: | :---------- |
| x-extendedDiscriminator | string | specifies extended discriminator |
###### How to use with Redoc
Redoc uses this vendor extension to solve name-clash issues with the standard `discriminator`.
Value of this field specifies the field which is used as an extended discriminator.
Redoc displays definition with selectpicker using which user can select value of the `x-extendedDiscriminator`-marked field.
Redoc displays the definition derived from the current (using `allOf`) and has `enum` with only one value which is the same as the selected value of the field specified as `x-extendedDiscriminator`.
###### x-extendedDiscriminator example
```yaml
Payment:
x-extendedDiscriminator: type
type: object
required:
- type
properties:
type:
type: string
name:
type: string
CashPayment:
allOf:
- $ref: "#/definitions/Payment"
- properties:
type:
type: string
enum:
- cash
currency:
type: string
PayPalPayment:
allOf:
- $ref: "#/definitions/Payment"
- properties:
type:
type: string
enum:
- paypal
userEmail:
type: string
```
In the example above, the names of definitions (`PayPalPayment`) are named differently than names in the payload (`paypal`) which is not supported by default `discriminator`.
#### x-additionalPropertiesName
**ATTENTION**: This is a Redoc-specific vendor extension, and is not supported by other tools.
Extends the `additionalProperties` property of the schema object.
| Field Name | Type | Description |
| :------------- | :------: | :---------- |
| x-additionalPropertiesName | string | descriptive name of additional properties keys |
###### How to use with Redoc
Redoc uses this extension to display a more descriptive property name in objects with `additionalProperties` when viewing the property list with an `object`.
###### x-additionalPropertiesName example
```yaml
Player:
required:
- name
properties:
name:
type: string
additionalProperties:
x-additionalPropertiesName: attribute-name
type: string
```
#### x-explicitMappingOnly
**ATTENTION**: This is Redoc-specific vendor extension, and is not supported by other tools.
Extends the `discriminator` property of the schema object.
| Field Name | Type | Description |
| :------------- | :------: | :---------- |
| x-explicitMappingOnly | boolean | limit the discriminator selectpicker to the explicit mappings only |
###### How to use with Redoc
Redoc uses this extension to filter the `discriminator` mappings shown in the selectpicker.
When set to `true`, the selectpicker lists only the explicitly defined mappings. When `false`, the default behavior is kept, in other words, explicit and implicit mappings are shown.
###### x-explicitMappingOnly example
```yaml
Pet:
type: object
required:
- name
- photoUrls
discriminator:
propertyName: petType
x-explicitMappingOnly: true
mapping:
cat: "#/components/schemas/Cat"
bee: "#/components/schemas/HoneyBee"
```
Shows in the selectpicker only the items `cat` and `bee`, even though the `Dog` class inherits from the `Pet` class.