REST API Overview

What is a REST API?

REST stands for representational state transfer. It's a particular type of API which employs HTTP requests and JavaScript Object Notation (JSON) to facilitate create, retrieve, update, and delete (CRUD) operations on objects within an application. Each type of operation is associated with a particular HTTP verb:

  • GET: Retrieve an object or list of objects
  • POST: Create an object
  • PUT / PATCH: Modify an existing object. PUT requires all mandatory fields to be specified, while PATCH only expects the field that is being modified to be specified.
  • DELETE: Delete an existing object

Additionally, the OPTIONS verb can be used to inspect a particular REST API endpoint and return all supported actions and their available parameters.

One of the primary benefits of a REST API is its human-friendliness. Because it utilizes HTTP and JSON, it's very easy to interact with NetBox data on the command line using common tools. For example, we can request an IP address from NetBox and output the JSON using curl and jq. The following command makes an HTTP GET request for information about a particular IP address, identified by its primary key, and uses jq to present the raw JSON data returned in a more human-friendly format. (Piping the output through jq isn't strictly required but makes it much easier to read.)

curl -s http://netbox/api/ipam/ip-addresses/2954/ | jq '.'
{
  "id": 2954,
  "url": "http://netbox/api/ipam/ip-addresses/2954/",
  "family": {
    "value": 4,
    "label": "IPv4"
  },
  "address": "192.168.0.42/26",
  "vrf": null,
  "tenant": null,
  "status": {
    "value": "active",
    "label": "Active"
  },
  "role": null,
  "assigned_object_type": "dcim.interface",
  "assigned_object_id": 114771,
  "assigned_object": {
    "id": 114771,
    "url": "http://netbox/api/dcim/interfaces/114771/",
    "device": {
      "id": 2230,
      "url": "http://netbox/api/dcim/devices/2230/",
      "name": "router1",
      "display_name": "router1"
    },
    "name": "et-0/1/2",
    "cable": null,
    "connection_status": null
  },
  "nat_inside": null,
  "nat_outside": null,
  "dns_name": "",
  "description": "Example IP address",
  "tags": [],
  "custom_fields": {},
  "created": "2020-08-04",
  "last_updated": "2020-08-04T14:12:39.666885Z"
}

Each attribute of the IP address is expressed as an attribute of the JSON object. Fields may include their own nested objects, as in the case of the assigned_object field above. Every object includes a primary key named id which uniquely identifies it in the database.

Interactive Documentation

Comprehensive, interactive documentation of all REST API endpoints is available on a running NetBox instance at /api/docs/. This interface provides a convenient sandbox for researching and experimenting with specific endpoints and request types. The API itself can also be explored using a web browser by navigating to its root at /api/.

Endpoint Hierarchy

NetBox's entire REST API is housed under the API root at https://<hostname>/api/. The URL structure is divided at the root level by application: circuits, DCIM, extras, IPAM, plugins, secrets, tenancy, users, and virtualization. Within each application exists a separate path for each model. For example, the provider and circuit objects are located under the "circuits" application:

  • /api/circuits/providers/
  • /api/circuits/circuits/

Likewise, the site, rack, and device objects are located under the "DCIM" application:

  • /api/dcim/sites/
  • /api/dcim/racks/
  • /api/dcim/devices/

The full hierarchy of available endpoints can be viewed by navigating to the API root in a web browser.

Each model generally has two views associated with it: a list view and a detail view. The list view is used to retrieve a list of multiple objects and to create new objects. The detail view is used to retrieve, update, or delete an single existing object. All objects are referenced by their numeric primary key (id).

  • /api/dcim/devices/ - List existing devices or create a new device
  • /api/dcim/devices/123/ - Retrieve, update, or delete the device with ID 123

Lists of objects can be filtered using a set of query parameters. For example, to find all interfaces belonging to the device with ID 123:

GET /api/dcim/interfaces/?device_id=123

See the filtering documentation for more details.

Serialization

The REST API employs two types of serializers to represent model data: base serializers and nested serializers. The base serializer is used to present the complete view of a model. This includes all database table fields which comprise the model, and may include additional metadata. A base serializer includes relationships to parent objects, but does not include child objects. For example, the VLANSerializer includes a nested representation its parent VLANGroup (if any), but does not include any assigned Prefixes.

{
    "id": 1048,
    "site": {
        "id": 7,
        "url": "http://netbox/api/dcim/sites/7/",
        "name": "Corporate HQ",
        "slug": "corporate-hq"
    },
    "group": {
        "id": 4,
        "url": "http://netbox/api/ipam/vlan-groups/4/",
        "name": "Production",
        "slug": "production"
    },
    "vid": 101,
    "name": "Users-Floor1",
    "tenant": null,
    "status": {
        "value": 1,
        "label": "Active"
    },
    "role": {
        "id": 9,
        "url": "http://netbox/api/ipam/roles/9/",
        "name": "User Access",
        "slug": "user-access"
    },
    "description": "",
    "display_name": "101 (Users-Floor1)",
    "custom_fields": {}
}

Related objects (e.g. ForeignKey fields) are represented using nested serializers. A nested serializer provides a minimal representation of an object, including only its direct URL and enough information to display the object to a user. When performing write API actions (POST, PUT, and PATCH), related objects may be specified by either numeric ID (primary key), or by a set of attributes sufficiently unique to return the desired object.

For example, when creating a new device, its rack can be specified by NetBox ID (PK):

{
    "name": "MyNewDevice",
    "rack": 123,
    ...
}

Or by a set of nested attributes which uniquely identify the rack:

{
    "name": "MyNewDevice",
    "rack": {
        "site": {
            "name": "Equinix DC6"
        },
        "name": "R204"
    },
    ...
}

Note that if the provided parameters do not return exactly one object, a validation error is raised.

Generic Relations

Some objects within NetBox have attributes which can reference an object of multiple types, known as generic relations. For example, an IP address can be assigned to either a device interface or a virtual machine interface. When making this assignment via the REST API, we must specify two attributes:

  • assigned_object_type - The content type of the assigned object, defined as <app>.<model>
  • assigned_object_id - The assigned object's unique numeric ID

Together, these values identify a unique object in NetBox. The assigned object (if any) is represented by the assigned_object attribute on the IP address model.

curl -X POST \
-H "Authorization: Token $TOKEN" \
-H "Content-Type: application/json" \
-H "Accept: application/json; indent=4" \
http://netbox/api/ipam/ip-addresses/ \
--data '{
    "address": "192.0.2.1/24",
    "assigned_object_type": "dcim.interface",
    "assigned_object_id": 69023
}'
{
    "id": 56296,
    "url": "http://netbox/api/ipam/ip-addresses/56296/",
    "assigned_object_type": "dcim.interface",
    "assigned_object_id": 69000,
    "assigned_object": {
        "id": 69000,
        "url": "http://netbox/api/dcim/interfaces/69023/",
        "device": {
            "id": 2174,
            "url": "http://netbox/api/dcim/devices/2174/",
            "name": "device105",
            "display_name": "device105"
        },
        "name": "ge-0/0/0",
        "cable": null,
        "connection_status": null
    },
    ...
}

If we wanted to assign this IP address to a virtual machine interface instead, we would have set assigned_object_type to virtualization.vminterface and updated the object ID appropriately.

Brief Format

Most API endpoints support an optional "brief" format, which returns only a minimal representation of each object in the response. This is useful when you need only a list of available objects without any related data, such as when populating a drop-down list in a form. As an example, the default (complete) format of an IP address looks like this:

GET /api/ipam/prefixes/13980/

{
    "id": 13980,
    "url": "http://netbox/api/ipam/prefixes/13980/",
    "family": {
        "value": 4,
        "label": "IPv4"
    },
    "prefix": "192.0.2.0/24",
    "site": {
        "id": 3,
        "url": "http://netbox/api/dcim/sites/17/",
        "name": "Site 23A",
        "slug": "site-23a"
    },
    "vrf": null,
    "tenant": null,
    "vlan": null,
    "status": {
        "value": "container",
        "label": "Container"
    },
    "role": {
        "id": 17,
        "url": "http://netbox/api/ipam/roles/17/",
        "name": "Staging",
        "slug": "staging"
    },
    "is_pool": false,
    "description": "Example prefix",
    "tags": [],
    "custom_fields": {},
    "created": "2018-12-10",
    "last_updated": "2019-03-01T20:02:46.173540Z"
}

The brief format is much more terse:

GET /api/ipam/prefixes/13980/?brief=1

{
    "id": 13980,
    "url": "http://netbox/api/ipam/prefixes/13980/",
    "family": 4,
    "prefix": "10.40.3.0/24"
}

The brief format is supported for both lists and individual objects.

Excluding Config Contexts

When retrieving devices and virtual machines via the REST API, each will included its rendered configuration context data by default. Users with large amounts of context data will likely observe suboptimal performance when returning multiple objects, particularly with very high page sizes. To combat this, context data may be excluded from the response data by attaching the query parameter ?exclude=config_context to the request. This parameter works for both list and detail views.

Pagination

API responses which contain a list of many objects will be paginated for efficiency. The root JSON object returned by a list endpoint contains the following attributes:

  • count: The total number of all objects matching the query
  • next: A hyperlink to the next page of results (if applicable)
  • previous: A hyperlink to the previous page of results (if applicable)
  • results: The list of objects on the current page

Here is an example of a paginated response:

HTTP 200 OK
Allow: GET, POST, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "count": 2861,
    "next": "http://netbox/api/dcim/devices/?limit=50&offset=50",
    "previous": null,
    "results": [
        {
            "id": 231,
            "name": "Device1",
            ...
        },
        {
            "id": 232,
            "name": "Device2",
            ...
        },
        ...
    ]
}

The default page is determined by the PAGINATE_COUNT configuration parameter, which defaults to 50. However, this can be overridden per request by specifying the desired offset and limit query parameters. For example, if you wish to retrieve a hundred devices at a time, you would make a request for:

http://netbox/api/dcim/devices/?limit=100

The response will return devices 1 through 100. The URL provided in the next attribute of the response will return devices 101 through 200:

{
    "count": 2861,
    "next": "http://netbox/api/dcim/devices/?limit=100&offset=100",
    "previous": null,
    "results": [...]
}

The maximum number of objects that can be returned is limited by the MAX_PAGE_SIZE configuration parameter, which is 1000 by default. Setting this to 0 or None will remove the maximum limit. An API consumer can then pass ?limit=0 to retrieve all matching objects with a single request.

Warning

Disabling the page size limit introduces a potential for very resource-intensive requests, since one API request can effectively retrieve an entire table from the database.

Interacting with Objects

Retrieving Multiple Objects

To query NetBox for a list of objects, make a GET request to the model's list endpoint. Objects are listed under the response object's results parameter.

curl -s -X GET http://netbox/api/ipam/ip-addresses/ | jq '.'
{
  "count": 42031,
  "next": "http://netbox/api/ipam/ip-addresses/?limit=50&offset=50",
  "previous": null,
  "results": [
    {
      "id": 5618,
      "address": "192.0.2.1/24",
      ...
    },
    {
      "id": 5619,
      "address": "192.0.2.2/24",
      ...
    },
    {
      "id": 5620,
      "address": "192.0.2.3/24",
      ...
    },
    ...
  ]
}

Retrieving a Single Object

To query NetBox for a single object, make a GET request to the model's detail endpoint specifying its unique numeric ID.

Note

Note that the trailing slash is required. Omitting this will return a 302 redirect.

curl -s -X GET http://netbox/api/ipam/ip-addresses/5618/ | jq '.'
{
  "id": 5618,
  "address": "192.0.2.1/24",
  ...
}

Creating a New Object

To create a new object, make a POST request to the model's list endpoint with JSON data pertaining to the object being created. Note that a REST API token is required for all write operations; see the authentication documentation for more information. Also be sure to set the Content-Type HTTP header to application/json.

curl -s -X POST \
-H "Authorization: Token $TOKEN" \
-H "Content-Type: application/json" \
http://netbox/api/ipam/prefixes/ \
--data '{"prefix": "192.0.2.0/24", "site": 6}' | jq '.'
{
  "id": 18691,
  "url": "http://netbox/api/ipam/prefixes/18691/",
  "family": {
    "value": 4,
    "label": "IPv4"
  },
  "prefix": "192.0.2.0/24",
  "site": {
    "id": 6,
    "url": "http://netbox/api/dcim/sites/6/",
    "name": "US-East 4",
    "slug": "us-east-4"
  },
  "vrf": null,
  "tenant": null,
  "vlan": null,
  "status": {
    "value": "active",
    "label": "Active"
  },
  "role": null,
  "is_pool": false,
  "description": "",
  "tags": [],
  "custom_fields": {},
  "created": "2020-08-04",
  "last_updated": "2020-08-04T20:08:39.007125Z"
}

Creating Multiple Objects

To create multiple instances of a model using a single request, make a POST request to the model's list endpoint with a list of JSON objects representing each instance to be created. If successful, the response will contain a list of the newly created instances. The example below illustrates the creation of three new sites.

curl -X POST -H "Authorization: Token $TOKEN" \
-H "Content-Type: application/json" \
-H "Accept: application/json; indent=4" \
http://netbox/api/dcim/sites/ \
--data '[
{"name": "Site 1", "slug": "site-1", "region": {"name": "United States"}},
{"name": "Site 2", "slug": "site-2", "region": {"name": "United States"}},
{"name": "Site 3", "slug": "site-3", "region": {"name": "United States"}}
]'
[
    {
        "id": 21,
        "url": "http://netbox/api/dcim/sites/21/",
        "name": "Site 1",
        ...
    },
    {
        "id": 22,
        "url": "http://netbox/api/dcim/sites/22/",
        "name": "Site 2",
        ...
    },
    {
        "id": 23,
        "url": "http://netbox/api/dcim/sites/23/",
        "name": "Site 3",
        ...
    }
]

Modifying an Object

To modify an object which has already been created, make a PATCH request to the model's detail endpoint specifying its unique numeric ID. Include any data which you wish to update on the object. As with object creation, the Authorization and Content-Type headers must also be specified.

curl -s -X PATCH \
> -H "Authorization: Token $TOKEN" \
> -H "Content-Type: application/json" \
> http://netbox/api/ipam/prefixes/18691/ \
> --data '{"status": "reserved"}' | jq '.'
{
  "id": 18691,
  "url": "http://netbox/api/ipam/prefixes/18691/",
  "family": {
    "value": 4,
    "label": "IPv4"
  },
  "prefix": "192.0.2.0/24",
  "site": {
    "id": 6,
    "url": "http://netbox/api/dcim/sites/6/",
    "name": "US-East 4",
    "slug": "us-east-4"
  },
  "vrf": null,
  "tenant": null,
  "vlan": null,
  "status": {
    "value": "reserved",
    "label": "Reserved"
  },
  "role": null,
  "is_pool": false,
  "description": "",
  "tags": [],
  "custom_fields": {},
  "created": "2020-08-04",
  "last_updated": "2020-08-04T20:14:55.709430Z"
}

PUT versus PATCH

The NetBox REST API support the use of either PUT or PATCH to modify an existing object. The difference is that a PUT request requires the user to specify a complete representation of the object being modified, whereas a PATCH request need include only the attributes that are being updated. For most purposes, using PATCH is recommended.

Deleting an Object

To delete an object from NetBox, make a DELETE request to the model's detail endpoint specifying its unique numeric ID. The Authorization header must be included to specify an authorization token, however this type of request does not support passing any data in the body.

curl -s -X DELETE \
-H "Authorization: Token $TOKEN" \
http://netbox/api/ipam/prefixes/18691/

Note that DELETE requests do not return any data: If successful, the API will return a 204 (No Content) response.

Note

You can run curl with the verbose (-v) flag to inspect the HTTP response codes.