Zenmeter Management API (2026-07-01:v1.0.2318)

This is the documentation for Zenmeter.

Zenmeter is a product in the Nalpeiron Growth Platform (NGP), which contains the Zentitle2, Zengain, and Zenmeter products. This API reference documents the Management API for Zenmeter within that broader NGP landscape.

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The Nalpeiron Growth Platform (NGP) Management API uses OAuth2 over https to manage authentication and authorization.

OAuth2 is an open standard for authorization that enables applications to securely access resources from other apps or services. We use client_credentials flow in the API.

In the client credentials flow, the app sends a request to the authorization server's token endpoint with its client ID and secret, which are used to authenticate the app. If the request is successful, the authorization server returns an access token, which the app can use to access protected resources on the resource server.

The client credentials flow is typically used by server-side apps or apps that run in a trusted environment, such as a secure server or device. It allows these apps to access protected resources on behalf of themselves, rather than on behalf of a user. This grant type is not suitable for browser-based apps or mobile apps, as it does not involve user interaction and does not provide a way for users to grant access to their protected resources.

Here is an example of how to generate client credentials for OAuth2:

1. Register your application in the NGP administration site in the "API Credentials" section.

2. During the registration process, the authorization server will provide you with a client secret for your provided client ID. These are unique, secret values that identify your app and are used to authenticate your requests to the authorization server.

3. In order to use the client credentials grant type, your app must be able to securely store the client ID and secret. These values should never be shared or exposed to anyone outside of your app, as they provide access to the authorization server on your app's behalf.

4. Once you have securely stored the client ID and secret, you can begin making requests to the authorization server's token endpoint using the client credentials grant type. This typically involves sending a POST request to the token endpoint, with the client ID and secret provided in the request body.

5. You will find the token endpoint URL in the NGP administration site in the "API Credentials" section.

6. If the request is successful, the authorization server will return an access token, which can be used to access protected resources on the resource server. The access token may also include a refresh token, which can be used to obtain a new access token when the original one expires.

Here is an example code in JavaScript that gets the access token:

var body = 'grant_type=client_credentials'
            + '&client_id=' + clientId
            + '&client_secret=' + clientSecret;
pm.sendRequest({
    url: oauth_url + '/protocol/openid-connect/token',
    method: 'POST',
    header: {
        'Content-Type': 'application/x-www-form-urlencoded',
        'Accept': 'application/json'
    },
    body: {
        mode: 'raw',
        raw: body
    }
}, function (err, res) {
    var response = res.json();
    environment.set("access_token", response.access_token);
    environment.set("token_time", Date.now() + response.expires_in * 1000);
});

Access token should be sent with every API request in the Authorization header as:

Authorization: Bearer eyJhbGciOiJSUzI1NiIsInR5cCI...

Whenever the Authorization section for an endpoint contains more than one role in the list, it means that any of those roles is sufficient to access this endpoint.

API requires one more header to be set with the tenant ID for your NGP account, for example:

N-TenantId: t_KRwhRp1yl0_9gsZjE5Yjaw

All NGP APIs adhere to the ISO 8601 standard for date and time formatting. For instance, "2021-12-31T23:59:59Z" signifies the final second of the year 2021 in the UTC time zone. The backend systems of NGP function in UTC, and as such, all DateTime fields returned by the API are also in UTC. To enhance the usability of our API, we accept datetime values in several formats:

• 2021-12-31T23:59:59Z - UTC time
• 2021-12-31T23:59:59 - dates without timezone information are assumed to be UTC time
• 2021-12-31T23:59:59+01:00 - time with timezone information

To set up Postman to use the NGP Management API and to test your setup, see Configure Postman.

In case of an error, API returns error status code along with ApiError object if applicable.

Please see API Versioning documentation for more information about our versioning strategy and how to select an API version.

2026-07-01

Initial release

Create, retrieve, and update customers shared across Nalpeiron products.