In order to use the API you will need a client_id and client_secret. Please contact us if you are interested in using our API in production, and we will provide these credentials.

Vehicle / hardware access via the Enode API is granted to your application by the User in a standard OAuth Authorization Code flow.

The authorization scheme documented here is the recommended approach for most situations. However, it is also possible to user other OAuth flows, non-confidential clients, and temporary users. Please feel free to contact us if you have any questions about your use-case or the integration of your existing infrastructure.

Preparation: Configure your OAuth client

Because Enode API implements the OAuth 2.0 spec completely and without modifications, you can avoid rolling your own OAuth client implementation and instead use a well-supported and battle-tested implementation. This is strongly recommended. Information on available OAuth clients for many languages is available here

To configure your chosen OAuth client, you will need these details:

• Your client_id
• Your client_secret
• Authorization URL: https://link.test.enode.io/oauth2/auth
• Token URL: https://link.test.enode.io/oauth2/token

// Node.js + openid-client example
const enodeIssuer = await Issuer.discover('https://link.test.enode.io');
const client = new enodeIssuer.Client({
  client_id: 'xyz',
  client_secret: 'shhhhh',
  redirect_uris: ['http://localhost:5000/callback'],
  response_types: ['code'],
});

Preparation: Obtain a client access token via OAuth Client Credentials Grant

Your OAuth client will have a method for using the OAuth 2.0 Client Credentials Grant to obtain an access token.

// Node.js + openid-client example
const clientAccessToken = await client.grant({grant_type: "client_credentials"});

This access token belongs to your client and is used for administrative actions, such as the next step.

This token should be cached by your server and reused until it expires, at which point your server should request a new one.

Step 1. Generate an Enode Link session for your User and launch the OAuth flow

When your User indicates that they want to connect their hardware to your app, your server must call Link User to generate an Enode Link session for your User. The User ID can be any string that uniquely identifies the User, but it is recommended that you use the primary key by which you identify the User within your application.

Example Request:

POST /users/{userId}/link HTTP/1.1
Authorization: Bearer {access_token}
{
  "forceLanguage": "no-NB",
  "vendor": "Tesla",
}

Example Response:

{
    "linkState": "ZjE2MzMxMGFiYmU4MzcxOTU1ZmRjMTU5NGU2ZmE4YTU3NjViMzIwY2YzNG",
}

The returned linkState must be stored by your server, attached to the session of the authenticated user for which it was generated.

Your OAuth client will provide a method to construct an authorization URL for your user. That method will require these details:

• Redirect URI - The URI to which your user should be redirected when the Oauth flow completes
• Scope - The OAuth scope(s) you wish to request access to (see list of valid values here)
• State - The value of linkState from the request above

To launch the OAuth flow, send your user to the authorization URL constructed by your OAuth client. This can be done in an embedded webview within a native iOS/Android app, or in the system's default browser.

// Node.js + openid-client + express example

// Construct an OAuth authorization URL
const authorizationUrl = client.authorizationUrl({
  scope: "offline_access all",
  state: linkState
});

// Redirect user to authorization URL
res.redirect(authorizationUrl);

Step 2. User grants consent

In the Link UI webapp the user will follow 3 steps:

1. Choose their hardware from a list of supported manufacturers (EVs and charging boxes). For certain EV makes it will be necessary to also select a charge box.
2. For each selection, the user will be presented with the login screen for that particular hardware. The user must successfully log in.
3. A summary of the requested scopes will be presented to the user. The user must choose whether to grant access to your application.

Step 3. OAuth flow concludes with a callback

When the user has completed their interactions, they will be redirected to the Redirect URI you provided in Step 1, with various metadata appended as query parameters.

Your OAuth client will have a method to parse and validate that metadata, and fetch the granted access and refresh tokens.

Among that metadata will be a state value - you must verify that it is equal to the linkState value persisted in Step 1, as a countermeasure against CSRF attacks.

// Node.js + openid-client + express example

// Fetch linkState from user session
const linkState = get(req, 'session.linkState');

// Parse relevant parameters from request URL
const params = client.callbackParams(req);

// Exchange authorization code for access and refresh tokens
// In this example, openid-client does the linkState validation check for us
const tokenSet = await client.oauthCallback('http://localhost:5000/callback', params, {state: linkState})

With the access token in hand, you can now access resources on behalf of the user.

When the User has completed the process of allowing/denying access in Enode Link, they will be redirected to your configured redirect URI. If something has gone wrong, query parameters error and error_description will be set as documented in Section 4.1.2.1 of the OAuth 2.0 spec:

Example:

https://website.example/oauth_callback?state=e0a86fe5&error=access_denied&error_description=The+resource+owner+or+authorization+server+denied+the+request.

When using an access_token to access a User's resources, the following HTTP Status Codes in the 4XX range may be encountered:

In all cases, an RFC7807 Problem Details body is returned to aid in debugging.

Example:

HTTP/1.1 400 Bad Request
Content-Type: application/problem+json
{
  "type": "https://docs.enode.io/problems/payload-validation-error",
  "title": "Payload validation failed",
  "detail": "\"authorizationRequest.scope\" is required",
}

Charging Locations are created by a user to denote locations where they pay for the power used to charge their vehicle. Smart Charging is active at these locations only.

Webhooks are a mechanism that allows your server to recieve notifications of events from the Enode system.

Currently, there is only one webhook available - a preconfigured webhook called Firehose that reports all supported events ocurring within the system. You can configure it using the Update Firehose Webhook endpoint.

Your webhook endpoint should expect to receive POST requests bearing the following headers:

And an application/json body containing an array of Events, with the following schema:

[
  {
    "event": "user:vehicle:updated", // String - name of the event
    "createdAt": "2020-04-07T17:04:26Z", // UTC ISO 8601 - time at which the event was triggered
  },
  ...
]

Each Event object may contain additional properties, depending on the event.

A cryptographically secure secret should be generated and persisted on your server.

You will provide it when configuring a webhook, such as Update Firehose Webhook, and you will again use it when verifying the signature of incoming webhook requests.

It should be a pseudorandom value of at least 128 bits, produced by a secure generator.

// Node.js example - 256 bits
const crypto = require("crypto");
const secret = crypto.randomBytes(32).toString("hex");

Requests made to your endpoint will bear a X-Enode-Signature header verifying that the request has come from us.

The signature is the HMAC hex digest of the payload, where:

• algorithm = sha1
• key = your secret provided during webhook configuration
• payload = The request body (a UTF-8 encoded string containing JSON - be sure to not deserialize it before signature computation)

The signature is then prefixed with "sha1="

In Javascript, the signature may be verified as follows:

// Node.js + Express example

// Read signature from request HTTP header
const enodeSignature = Buffer.from(req.get("X-Enode-Signature"), "utf8");

// Compute signature using your secret and the request payload
const payload = req.body;
const hmac = crypto.createHmac("sha1", <your secret>);
const digest = Buffer.from("sha1=" + hmac.update(payload).digest("hex"), "utf8");

// Check whether they match, using timing-safe equality (don't use ==)
if (!crypto.timingSafeEqual(digest, enodeSignature)) {
  throw new Error("Signature invalid");
}

user:vehicle:updated payload containing 1 event:

[
  {
    "event": "user:vehicle:updated",
    "createdAt": "2020-04-07T17:04:26Z",
    "user": { // the user whose vehicle was updated
      "id": "8d90101b-3f2f-462a-bbb4-1ed320d33bbe"
    },
    "vehicle": { // the vehicle whose properties were updated
      "id": "e8af7ddf-01ce-4ff7-b850-45888708cc0a",
      "lastSeen": "2020-04-07T17:04:26Z",
      "chargeState": {
        "batteryLevel": "38",
        "range": "127.5",
      },
      "location": {
        "longitude": 10.757933,
        "latitude": 59.911491,
        "lastUpdated": "2020-04-07T17:04:26Z"
      },
    },
  }
]

The vehicle property follows the same schema as Get Vehicle, and only changed fields will be populated.

The Me endpoint returns metadata about the authenticated User.