# Querying All API Versions

#### Function

This API is used to query all available Nova versions.

To support function extension, Nova APIs can be distinguished by version. There are two types of versions:

- Major version: Independent URL
- Microversion: Used by the HTTP request header X-OpenStack-Nova-API-Version. Since microversion 2.27, the new microversion header OpenStack-API-Version has been supported.

#### URI

GET /

#### Request

None

#### Response

The following table describes the response parameters.

Table 1 Response parameters
Parameter | Type | Description
--- | --- | ---
versions | Object | Specifies the API versions. For details, see Table 2.

Table 2 versions field description
Parameter | Type | Description
--- | --- | ---
id | string | Specifies the version ID.
links | Object | Specifies shortcut links for versions. For details, see Table 3.

min_version

string

- Specifies the microversion. If the APIs of this version support microversions, set this parameter to the supported minimum microversion.
- If the microversion is not supported, leave this parameter blank.

status

string

Specifies the API version status. Possible values are as follows:

- CURRENT: This is the preferred API version.
- SUPPORTED: This is the old API version that is still supported.
- DEPRECATED: This is the deprecated API version that will be removed.

version

string

- Specifies the microversion. If the APIs of this version support microversions, set this parameter to the supported maximum microversion.
- If the microversion is not supported, leave this parameter blank.

updated | string | The value of this parameter varies by API version. If the API version is 2.0, the value is 2011-01-21T11:33:21Z. If the API version is 2.1, the value is 2013-07-23T11:33:21Z.

Table 3 links field description
Parameter | Type | Description
--- | --- | ---
href | string | Specifies the links of the corresponding resources.

rel

string

- self: A self link contains a versioned link to the resource. Use these links when the link is followed immediately.
- bookmark: A bookmark link provides a permanent link to a resource that is appropriate for long term storage.
- alternate: An alternate link can contain an alternate representation of the resource.

  For example, an OpenStack Compute image might have an alternate representation in the OpenStack Image service.

#### Example Request

    GET https://{endpoint}/

#### Example Response

    {
     "versions": [{
      "links": [{
       "rel": "self",
       "href": "https://ecs.service.domain.com:443/v2/"
      }],
      "id": "v2.0",
      "updated": "2001-09-21T12:33:21Z",
      "status": "SUPPORTED"
     }]
    }

#### Returned Values

See Returned Values for General Requests.

Parent topic: API Version Query