Introduction to the REST API¶
This section introduces the nRF Cloud REST APIs. If you are not familiar with REST APIs, start with the Postman Learning Center.
See the API overview for a full list of API references.
The nRF Cloud REST API¶
The nRF Cloud REST API references are built on the OpenAPI 3.x specification. You can get the current schema as a JSON file in one of the following ways:
- In any web browser, open and download https://api.nrfcloud.com/v1/openapi.json.
- In any REST tool, call
GET https://api.nrfcloud.com/v1/openapi.json
. - At the top of the API reference introduction page, click the Download button.
REST tools, such as Postman or Insomnia, can parse the downloaded file and create a collection of endpoints for you.
Devices using the REST API must also use modem firmware v1.3.x, which has its own hardware requirements as described in the release notes.
Authentication¶
The REST API authenticates users with an API key, and devices with a JSON Web Token (JWT). Only a subset of the nRF Cloud REST API endpoints should be called by devices instead of users. These endpoints indicate JSON Web Token
in the Authorizations
section. Otherwise, Simple Token
is indicated.
Some endpoints, like FetchCurrentPendingFOTAJobExecution
, support both schemes.
Tokens and keys¶
Authenticating requests to nRF Cloud involves tokens and keys.
A token is used to authenticate a request to the nRF Cloud APIs:
- An API key.
- An evaluation token, a specific kind of JWT for Location Services.
- A JWT.
A key can refer to the following:
- A public or private key used to sign a JWT.
- A service key used to sign tokens for Location Services.
See more on generating tokens and keys.
API key¶
Some requests, usually those that come from a user and not a device, require a simple authentication token in the Authorization
header. Here is a cURL example of this header:
-H "Authorization: Bearer d8be845e816e45d4a9529a6cfcd459c88e3c22b5"
Note
API keys function as tokens, not keys. In some API references, an API key is referred to as a simple token.
See how to generate and retrieve API keys in the nRF Cloud portal. API keys are specific not only to the user, but the team. Your API key is different for each team.
This token is used for endpoints and operations other than Location Services and FOTA, and does not need to be signed with a key. The API key is also used to authorize requests based on user role.
Evaluation token¶
An evaluation token lets you and your team try nRF Cloud Location Services free for thirty days. The trial period starts once you generate the token. Once the trial period is over, you need a JWT signed with a service key.
The evaluation token is a type of JWT and used in the same way. See Using JWTs in requests for more information.
See how to set up a plan that includes access to Location Services.
If you are using an evaluation token, you do not need to separately generate a service key. All applicable services are enabled for all devices automatically.
JWT¶
REST endpoints intended for devices or proxy servers require a JSON Web Token (JWT). A JWT authenticates a request to a service from a device, so nRF Cloud can verify that it is from that device.
JWT payloads¶
The payload for each JWT depends on the type of key used:
Signing (private) key | Payload |
---|---|
Device key | The sub claim must contain the device ID. If your device is using its internal UUID as the device ID and modem_jwt_generate, omit the sub claim. Do not include the aud claim. |
Service key | The aud claim must contain your Team ID. The sub claim may contain a device ID if the request is servicing a single device. |
Creating JWTs¶
The most secure way to use JWTs from devices is with the Modem JWT library or using the AT%JWT
command directly. This requires modem firmware v1.3.x or later.
JWTs generated by the modem automatically contain the device UUID in the payload's iss
claim. This is useful if your device uses its UUID as its device ID, in which case, you can omit the subject
claim.
If your device uses a different value for the device ID, you must provide that value as the subject
claim of the JWT. For example, if you want to use JWTs on Nordic Semiconductor products that have a device ID formatted as nrf-[IMEI]
, as is the case for the nRF9160 DK and Thingy:91, you must either provision a new certificate that uses the UUID (and re-provision the device on nRF Cloud), or pass the nrf-[IMEI]
ID as the subject
to the AT%JWT
command.
Using JWTs in requests¶
Add the generated JWT to the Authorization
header as a Bearer
token. Here is a cURL example:
-H "Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJkZXZpY2VJZGVudGlmaWVyIjoiZmIwOWNkZmItZTY4Yy00NGUzLWIwMTQtMmJlZDc4Yzk3OTQ5In0.RUAWePWjqRn4TK6EXsiKrsMM69FqDjg7dn52hrqG8CM"
Signing (private) and verification (public) keys¶
JWTs must be signed by the private key of an ES256 asymmetric key pair. It is the only JWT algorithm supported by nRF Cloud.
Note
The nRF9160 DK and Thingy:91 are shipped with RSA256 certificates, which are not supported for JWT signing by modem firmware v1.3.x and later. To use JWTs with these devices, delete the device from nRF Cloud and re-provision it with a new ES256 device certificate.
When a JWT is received by an nRF Cloud endpoint, its digital signature must be verified by the corresponding public key.
nRF Cloud supports two types of private keys:
- Device key: generated on the device and unique for each device.
- Service key: generated by nRF Cloud and unique for each service, such as Location Services. This is typically only used for proxy servers.
Access
Generating a service key requires a Pro or Enterprise plan and a team owner role.
nRF Cloud obtains public keys in one of the following ways:
- Device key:
- Upload the key manually with the
RegisterPublicKeys
endpoint. - nRF Cloud automatically extracts the device key from the device's non-JITP certificate during the provisioning process.
- nRF Cloud automatically extracts the device key from the device's JITP certificate, if applicable and no other public key can be found to verify the signature.
- Service key: nRF Cloud generates and stores the service key on demand through the nRF Cloud portal.
Service key¶
A service key allows you to use Location Services with a proxy server. A service key can be public or private.
Once you generate a key, you need to generate a new JWT signed with the service key.
Access
Generating a service key requires a Pro or Enterprise plan and team owner role.
If you are using an evaluation token, you do not need to generate a service key.
REST client tools¶
You can call the REST API with a REST client tool such as Insomnia or Postman.
Use cURL or other utilities to call APIs from the command line.
If-match headers¶
API endpoints that change existing resources, such as UpdateDeviceName
, allow you to include an optional If-Match
header to avoid lost updates.
The value for this header is taken from the $meta.version
property. The value is also available in the ETag
for endpoints that return a single resource, for example, FetchDevice
.
If the version you pass is not equal to the latest version of the resource, you get an HTTP 412
and PreconditionFailedError
.
Additional resources¶
See the following guides for next steps:
- JWT authentication on nRF Cloud.
- Getting started with your devices.
- Managing tokens and keys.
- Using the REST API for Bluetooth® Low Energy devices.
- Transforming JSON responses.