New to the IoT side of things, I’m a backend dev and got handed this.
We have a tank level sensor already reporting to Hermetry (device “tank-01”, key level_pct). Someone wants a Pi in the office that sounds a buzzer when the level goes over 90. My plan was a tiny Python service on the Pi that polls Hermetry every 5 seconds for the latest value. I copied the access token from tank-01’s page and did:
GET https://<host>/api/telemetry/latest?kind=iot_device&entityId=6f1c...&keys=level_pct
Authorization: Bearer <tank-01 token>
-> 401Tried with and without “Bearer”, same. Is the token wrong or is this the wrong endpoint?
That’s a device credential. It logs a device in, it doesn’t read anything for you. The management API wants an API key. Also every 5 seconds is a lot for a buzzer.
Brian’s right, and you’re also missing the organisation prefix. I set up nearly the same thing for a chiller room last year.
1. API Keys (Developer menu) > New API Key. Under Module permissions give it read-only telemetry, nothing else. Set an IP allowlist to the office’s address, and note the expiry, default is 90 days, a year at most. Put a reminder in the calendar, ours expired on a Saturday.
2. Every management path sits under the tenant:
GET https://<host>/tenant/<tenantId>/api/telemetry/latest?kind=iot_device&entityId=<deviceId>&keys=level_pct
Authorization: Bearer sk_live_...Answer looks like {“latest”: {“level_pct”: {“ts”: …, “value”: 91.2}}}. Compare the ts with the previous one so you don’t buzz twice on the same reading.
3. Handle 429 and wait the Retry-After seconds. Poll every 30 s or so, the tank doesn’t fill in 5.
The other route, if you want it instant: make the Pi a device itself, have a rule on the tank send it a command when level_pct rises above 90, and let the Pi wait on GET /api/v1/rpc with its own device token. More moving parts, no polling. For a buzzer I’d take the API key. Conventions are on REST API basics.
That was two bugs, the token and the missing /tenant/<tenantId> bit (got a 404 once I had the key, then saw it). Running at 30 s now with a read-only key locked to our IP. Buzzer went off this morning when they filled it, so it works.
Store the key in a root-only file, not in the script you’ll paste into a ticket some day.
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