REST API Version History

REST API Version History

This documents the changes made to the REST API with every microversion change. The description for each version should be a verbose one which has enough information to be suitable for use in user documentation.


This is the initial version of the v2.1 API which supports microversions. The V2.1 API is from the REST API users's point of view exactly the same as v2.0 except with strong input validation.

A user can specify a header in the API request:

X-OpenStack-Nova-API-Version: <version>

where <version> is any valid api version for this API.

If no version is specified then the API will behave as if a version request of v2.1 was requested.


Added Keypair type.

A user can request the creation of a certain 'type' of keypair (ssh or x509) in the os-keypairs plugin

If no keypair type is specified, then the default ssh type of keypair is created.

Fixes status code for os-keypairs create method from 200 to 201

Fixes status code for os-keypairs delete method from 202 to 204

2.3 (Maximum in Kilo)

Exposed additional attributes in os-extended-server-attributes: reservation_id, launch_index, ramdisk_id, kernel_id, hostname, root_device_name, userdata.

Exposed delete_on_termination for volumes_attached in os-extended-volumes.

This change is required for the extraction of EC2 API into a standalone service. It exposes necessary properties absent in public nova APIs yet. Add info for Standalone EC2 API to cut access to Nova DB.


Show the reserved status on a FixedIP object in the os-fixed-ips API extension. The extension allows one to reserve and unreserve a fixed IP but the show method does not report the current status.


Before version 2.5, the command nova list --ip6 xxx returns all servers for non-admins, as the filter option is silently discarded. There is no reason to treat ip6 different from ip, though, so we just add this option to the allowed list.


A new API for getting remote console is added:

POST /servers/<uuid>/remote-consoles
  "remote_console": {
    "protocol": ["vnc"|"rdp"|"serial"|"spice"],
    "type": ["novnc"|"xpvnc"|"rdp-html5"|"spice-html5"|"serial"]

Example response:

  "remote_console": {
    "protocol": "vnc",
    "type": "novnc",
    "url": ""

The old APIs 'os-getVNCConsole', 'os-getSPICEConsole', 'os-getSerialConsole' and 'os-getRDPConsole' are removed.


Check the is_public attribute of a flavor before adding tenant access to it. Reject the request with HTTPConflict error.


Add 'mks' protocol and 'webmks' type for remote consoles.


Add a new locked attribute to the detailed view, update, and rebuild action. locked will be true if anyone is currently holding a lock on the server, false otherwise.


Added user_id parameter to os-keypairs plugin, as well as a new property in the request body, for the create operation.

Administrators will be able to list, get details and delete keypairs owned by users other than themselves and to create new keypairs on behalf of their users.


Exposed attribute forced_down for os-services. Added ability to change the forced_down attribute by calling an update.

2.12 (Maximum in Liberty)

Exposes VIF net_id attribute in os-virtual-interfaces. User will be able to get Virtual Interfaces net_id in Virtual Interfaces list and can determine in which network a Virtual Interface is plugged into.


Add information project_id and user_id to os-server-groups API response data.


Remove onSharedStorage parameter from server's evacuate action. Nova will automatically detect if the instance is on shared storage. Also adminPass is removed from the response body. The user can get the password with the server's os-server-password action.


From this version of the API users can choose 'soft-affinity' and 'soft-anti-affinity' rules too for server-groups.


Exposes new host_status attribute for servers/detail and servers/{server_id}. Ability to get nova-compute status when querying servers. By default, this is only exposed to cloud administrators.


Add a new API for triggering crash dump in an instance. Different operation systems in instance may need different configurations to trigger crash dump.


Establishes a set of routes that makes project_id an optional construct in v2.1.


Allow the user to set and get the server description. The user will be able to set the description when creating, rebuilding, or updating a server, and get the description as part of the server details.


From this version of the API user can call detach and attach volumes for instances which are in shelved and shelved_offloaded state.


The os-instance-actions API now returns information from deleted instances.


A new resource servers:migrations added. A new API to force live migration to complete added:

POST /servers/<uuid>/migrations/<id>/action
  "force_complete": null


From this version of the API users can get the migration summary list by index API or the information of a specific migration by get API. And the old top-level resource /os-migrations won't be extended anymore. Add migration_type for old /os-migrations API, also add ref link to the /servers/{uuid}/migrations/{id} for it when the migration is an in-progress live-migration.


A new API call to cancel a running live migration:

DELETE /servers/<uuid>/migrations/<id>

2.25 (Maximum in Mitaka)

Modify input parameter for os-migrateLive. The block_migration will support 'auto' value, and disk_over_commit flag will be removed.


Added support of server tags.

A user can create, update, delete or check existence of simple string tags for servers by the os-server-tags plugin.

Tags have the following schema restrictions:

  • Tag is a Unicode bytestring no longer than 60 characters.
  • Tag is a non-empty string.
  • '/' is not allowed to be in a tag name
  • Comma is not allowed to be in a tag name in order to simplify requests that specify lists of tags
  • All other characters are allowed to be in a tag name
  • Each server can have up to 50 tags.

The resource point for these operations is /servers/<server_id>/tags

A user can add a single tag to the server by sending PUT request to the /servers/<server_id>/tags/<tag>

where <tag> is any valid tag name.

A user can replace all current server tags to the new set of tags by sending PUT request to the /servers/<server_id>/tags. New set of tags must be specified in request body. This set must be in list 'tags'.

A user can remove specified tag from the server by sending DELETE request to the /servers/<server_id>/tags/<tag>

where <tag> is tag name which user wants to remove.

A user can remove all tags from the server by sending DELETE request to the /servers/<server_id>/tags

A user can get a set of server tags with information about server by sending GET request to the /servers/<server_id>

Request returns dictionary with information about specified server, including list 'tags'

    'id': {server_id},
    'tags': ['foo', 'bar', 'baz']

A user can get only a set of server tags by sending GET request to the /servers/<server_id>/tags


   'tags': ['foo', 'bar', 'baz']

A user can check if a tag exists or not on a server by sending GET /servers/{server_id}/tags/{tag}

Request returns 204 No Content if tag exist on a server or 404 Not Found if tag doesn't exist on a server.

A user can filter servers in GET /servers request by new filters:

  • tags
  • tags-any
  • not-tags
  • not-tags-any

These filters can be combined. Also user can use more than one string tags for each filter. In this case string tags for each filter must be separated by comma: GET /servers?tags=red&tags-any=green,orange


Added support for the new form of microversion headers described in the Microversion Specification. Both the original form of header and the new form is supported.


Nova API hypervisor.cpu_info change from string to JSON object.

From this version of the API the hypervisor's 'cpu_info' field will be will returned as JSON object (not string) by sending GET request to the /v2.1/os-hypervisors/{hypervisor_id}.


Updates the POST request body for the evacuate action to include the optional force boolean field defaulted to False. Also changes the evacuate action behaviour when providing a host string field by calling the nova scheduler to verify the provided host unless the force attribute is set.


Updates the POST request body for the live-migrate action to include the optional force boolean field defaulted to False. Also changes the live-migrate action behaviour when providing a host string field by calling the nova scheduler to verify the provided host unless the force attribute is set.


Fix os-console-auth-tokens to return connection info for all types of tokens, not just RDP.


Adds an optional, arbitrary 'tag' item to the 'networks' item in the server boot request body. In addition, every item in the block_device_mapping_v2 array can also have an optional, arbitrary 'tag' item. These tags are used to identify virtual device metadata, as exposed in the metadata API and on the config drive. For example, a network interface on the virtual PCI bus tagged with 'nic1' will appear in the metadata along with its bus (PCI), bus address (ex: 0000:00:02.0), MAC address, and tag ('nic1').


A bug has caused the tag attribute to no longer be accepted for networks starting with version 2.37 and for block_device_mapping_v2 starting with version 2.33. In other words, networks could only be tagged between versions 2.32 and 2.36 inclusively and block devices only in version 2.32. As of version 2.42 the tag attribute has been restored and both networks and block devices can be tagged again.


Support pagination for hypervisor by accepting limit and marker from the GET API request:

GET /v2.1/{tenant_id}/os-hypervisors?marker={hypervisor_id}&limit={limit}

In the context of device tagging at server create time, 2.33 also removes the tag attribute from block_device_mapping_v2. This is a bug that is fixed in 2.42, in which the tag attribute is reintroduced.


Checks in os-migrateLive before live-migration actually starts are now made in background. os-migrateLive is not throwing 400 Bad Request if pre-live-migration checks fail.


Added pagination support for keypairs.

Optional parameters 'limit' and 'marker' were added to GET /os-keypairs request, the default sort_key was changed to 'name' field as ASC order, the generic request format is:

GET /os-keypairs?limit={limit}&marker={kp_name}


All the APIs which proxy to another service were deprecated in this version, also the fping API. Those APIs will return 404 with Microversion 2.36. The network related quotas and limits are removed from API also. The deprecated API endpoints as below:



A regression was introduced in this microversion which broke the force parameter in the PUT /os-quota-sets API. The fix will have to be applied to restore this functionality.


Added support for automatic allocation of networking, also known as "Get Me a Network". With this microversion, when requesting the creation of a new server (or servers) the networks entry in the server portion of the request body is required. The networks object in the request can either be a list or an enum with values:

  1. none which means no networking will be allocated for the created server(s).
  2. auto which means either a network that is already available to the project will be used, or if one does not exist, will be automatically created for the project. Automatic network allocation for a project only happens once for a project. Subsequent requests using auto for the same project will reuse the network that was previously allocated.

Also, the uuid field in the networks object in the server create request is now strictly enforced to be in UUID format.

In the context of device tagging at server create time, 2.37 also removes the tag attribute from networks. This is a bug that is fixed in 2.42, in which the tag attribute is reintroduced.

2.38 (Maximum in Newton)

Before version 2.38, the command nova list --status invalid_status was returning empty list for non admin user and 500 InternalServerError for admin user. As there are sufficient statuses defined already, any invalid status should not be accepted. From this version of the API admin as well as non admin user will get 400 HTTPBadRequest if invalid status is passed to nova list command.


Deprecates image-metadata proxy API that is just a proxy for Glance API to operate the image metadata. Also removes the extra quota enforcement with Nova metadata quota (quota checks for 'createImage' and 'createBackup' actions in Nova were removed). After this version Glance configuration option image_property_quota should be used to control the quota of image metadatas. Also, removes the maxImageMeta field from os-limits API response.


Optional query parameters limit and marker were added to the os-simple-tenant-usage endpoints for pagination. If a limit isn’t provided, the configurable max_limit will be used which currently defaults to 1000.

GET /os-simple-tenant-usage?limit={limit}&marker={instance_uuid}
GET /os-simple-tenant-usage/{tenant_id}?limit={limit}&marker={instance_uuid}

A tenant’s usage statistics may span multiple pages when the number of instances exceeds limit, and API consumers will need to stitch together the aggregate results if they still want totals for all instances in a specific time window, grouped by tenant.

Older versions of the os-simple-tenant-usage endpoints will not accept these new paging query parameters, but they will start to silently limit by max_limit to encourage the adoption of this new microversion, and circumvent the existing possibility of DoS-like usage requests when there are thousands of instances.


The 'uuid' attribute of an aggregate is now returned from calls to the /os-aggregates endpoint. This attribute is auto-generated upon creation of an aggregate. The os-aggregates API resource endpoint remains an administrator-only API.

2.42 (Maximum in Ocata)

In the context of device tagging at server create time, a bug has caused the tag attribute to no longer be accepted for networks starting with version 2.37 and for block_device_mapping_v2 starting with version 2.33. Microversion 2.42 restores the tag parameter to both networks and block_device_mapping_v2, allowing networks and block devices to be tagged again.


The os-hosts API is deprecated as of the 2.43 microversion. Requests made with microversion >= 2.43 will result in a 404 error. To list and show host details, use the os-hypervisors API. To enable or disable a service, use the os-services API. There is no replacement for the shutdown, startup, reboot, or maintenance_mode actions as those are system-level operations which should be outside of the control of the compute service.


The following APIs which are considered as proxies of Neutron networking API, are deprecated and will result in a 404 error response in new Microversion:

POST /servers/{server_uuid}/action
    "addFixedIp": {...}

POST /servers/{server_uuid}/action
    "removeFixedIp": {...}

POST /servers/{server_uuid}/action
    "addFloatingIp": {...}

POST /servers/{server_uuid}/action
    "removeFloatingIp": {...}

Those server actions can be replaced by calling the Neutron API directly.

The nova-network specific API to query the server's interfaces is deprecated:

GET /servers/{server_uuid}/os-virtual-interfaces

To query attached neutron interfaces for a specific server, the API GET /servers/{server_uuid}/os-interface can be used.


The createImage and createBackup server action APIs no longer return a Location header in the response for the snapshot image, they now return a json dict in the response body with an image_id key and uuid value.


The request_id created for every inbound request is now returned in X-OpenStack-Request-ID in addition to X-Compute-Request-ID to be consistent with the rest of OpenStack. This is a signaling only microversion, as these header settings happen well before microversion processing.


Replace the flavor name/ref with the actual flavor details from the embedded flavor object when displaying server details. Requests made with microversion >= 2.47 will no longer return the flavor ID/link but instead will return a subset of the flavor details. If the user is prevented by policy from indexing extra-specs, then the extra_specs field will not be included in the flavor information.


Before version 2.48, VM diagnostics response was just a 'blob' of data returned by each hypervisor. From this version VM diagnostics response is standardized. It has a set of fields which each hypervisor will try to fill. If a hypervisor driver is unable to provide a specific field then this field will be reported as 'None'.


Continuing from device role tagging at server create time introduced in version 2.32 and later fixed in 2.42, microversion 2.49 allows the attachment of network interfaces and volumes with an optional tag parameter. This tag is used to identify the virtual devices in the guest and is exposed in the metadata API. Because the config drive cannot be updated while the guest is running, it will only contain metadata of devices that were tagged at boot time. Any changes made to devices while the instance is running - be it detaching a tagged device or performing a tagged device attachment - will not be reflected in the config drive.

Tagged volume attachment is not supported for shelved-offloaded instances.


The server_groups and server_group_members keys are exposed in GET & PUT os-quota-class-sets APIs Response body. Networks related quotas have been filtered out from os-quota-class. Below quotas are filtered out and not available in os-quota-class-sets APIs from this microversion onwards.

  • "fixed_ips"
  • "floating_ips"
  • "networks",
  • "security_group_rules"
  • "security_groups"


There are two changes for the 2.51 microversion:

  • Add volume-extended event name to the os-server-external-events API. This will be used by the Block Storage service when extending the size of an attached volume. This signals the Compute service to perform any necessary actions on the compute host or hypervisor to adjust for the new volume block device size.
  • Expose the events field in the response body for the GET /servers/{server_id}/os-instance-actions/{request_id} API. This is useful for API users to monitor when a volume extend operation completes for the given server instance. By default only users with the administrator role will be able to see event traceback details.


Adds support for applying tags when creating a server. The tag schema is the same as in the 2.26 microversion.

2.53 (Maximum in Pike)


Services are now identified by uuid instead of database id to ensure uniqueness across cells. This microversion brings the following changes:

  • GET /os-services returns a uuid in the id field of the response

  • DELETE /os-services/{service_uuid} requires a service uuid in the path

  • The following APIs have been superseded by PUT /os-services/{service_uuid}/:

    • PUT /os-services/disable
    • PUT /os-services/disable-log-reason
    • PUT /os-services/enable
    • PUT /os-services/force-down

    PUT /os-services/{service_uuid} takes the following fields in the body:

    • status - can be either "enabled" or "disabled" to enable or disable the given service
    • disabled_reason - specify with status="disabled" to log a reason for why the service is disabled
    • forced_down - boolean indicating if the service was forced down by an external service
  • PUT /os-services/{service_uuid} will now return a full service resource representation like in a GET response


Hypervisors are now identified by uuid instead of database id to ensure uniqueness across cells. This microversion brings the following changes:

  • GET /os-hypervisors/{hypervisor_hostname_pattern}/search is deprecated and replaced with the hypervisor_hostname_pattern query parameter on the GET /os-hypervisors and GET /os-hypervisors/detail APIs. Paging with hypervisor_hostname_pattern is not supported.
  • GET /os-hypervisors/{hypervisor_hostname_pattern}/servers is deprecated and replaced with the with_servers query parameter on the GET /os-hypervisors and GET /os-hypervisors/detail APIs.
  • GET /os-hypervisors/{hypervisor_id} supports the with_servers query parameter to include hosted server details in the response.
  • GET /os-hypervisors/{hypervisor_id} and GET /os-hypervisors/{hypervisor_id}/uptime APIs now take a uuid value for the {hypervisor_id} path parameter.
  • The GET /os-hypervisors and GET /os-hypervisors/detail APIs will now use a uuid marker for paging across cells.
  • The following APIs will now return a uuid value for the hypervisor id and optionally service id fields in the response:
    • GET /os-hypervisors
    • GET /os-hypervisors/detail
    • GET /os-hypervisors/{hypervisor_id}
    • GET /os-hypervisors/{hypervisor_id}/uptime
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