Getting Started
The shortest path to your first camera-based measurement.
This is the linear "new developer" path. It links out to the detailed per-platform sections.
1. Create an account and one key
Sign up at console.neccessory.com. Then create one key. A key is a single credential: a public key id and a secret.
- The key id is safe to embed and log. It is sent as the
x-key-idheader. New ids begin withnk_live_—nk_test_on a test key. - The secret is shown once, at creation — copy it then. We store only its hash and cannot show it again; a lost secret is replaced by rotating the key.
That one key is all you need — there are no separate app keys. At creation you
choose its metric sets, and cloud measurements draw from the organization's
token balance, which starts with a welcome grant.
A key has a mode, picked in the create dialog: cloud is the default and
works immediately, test is always there for your CI, and on_device — the mode
that lets a client download model weights — appears once your application is
approved. See Obtaining keys for all three.
2. Add an SDK
Web
Init the SDK with your key id and secret, start, and subscribe to callbacks.
iOS
Init the SDK, feed camera frames, and receive a result.
3. Take a measurement
Start the SDK, keep a face in view, and hold still. A heart rate appears within about 10 seconds; a full measurement completes in roughly 30–35 seconds and returns a single measurement result.
4. Read the metrics
Every platform returns the same measurement result: Core metrics (heart rate, HRV, breathing rate, stress), Advanced (Beta) metrics (blood pressure, SpO2), and a required signal-quality rating. The Metrics reference explains each one — its unit, typical range, and when it works.
5. (Optional) Submit measurements to the API
This step is for the on-device tier. There the SDK runs the whole pipeline locally and nothing is transmitted during the measurement, so if you want completed measurements attributed to your account server-side you submit them to the REST API with the same key, HMAC-signed. The API is only for storing the result, never for uploading video.
In the cloud tier there is nothing to submit: the metrics are computed on our servers and the measurement is already stored when you receive it — see Cloud quickstart. The trade is that cloud measurements transmit cropped images of the face during capture; read Cloud privacy before choosing that tier.