opensense
HONEST TELEMETRY · SELF-SERVE · €29 / MONTH

If you measure it,
OpenSense remembers it.

Plug any commodity sensor into any small operation — a fridge, a hot-water loop, a server rack, a meeting room, a workshop feed. We log every minute, fire alarms before things break, and keep an audit trail an inspector or insurer will accept.

PRICE
€29 / mo
SETUP
~10 min
RETENTION
2 years
LIVE · KITCHEN-01
HACCP · EU 852/2004
WALK-IN FRIDGE
4.3°C
RANGE 2.0 … 6.0 · WITHIN SPEC
MIN/24h
3.7
AVG/24h
4.5
MAX/24h
5.7

live demo · cycles through real sensor profiles every ~6s

What people log

FIG. 01 · 5 ACTIVE VERTICALS
CC
Cold chain
Cafés, restaurants, bakeries, pharmacies
RULE
EU 852/2004 — HACCP records
CHANNELS
walk-in fridge · pastry display · medicine fridge · freezer
HW
Hot-water systems
Hotels, spas, care homes, gyms
RULE
EU 2020/2184 — legionella floor 60 °C
CHANNELS
boiler loop · return line · circulation pumps
IT
Server rooms
MSPs, dental offices, small SaaS, NOC closets
RULE
Insurance · uptime SLAs
CHANNELS
rack inlet · floor temp · door · UPS load
IAQ
Indoor climate
Schools, offices, museums, instrument & wine storage
RULE
CO₂ ventilation norms · humidity for collections
CHANNELS
classroom CO₂ · gallery humidity · cellar dew-point
EN
Energy & loads
Workshops, laundries, small manufacturers
RULE
Aberration detection · cost control
CHANNELS
main feed · per-machine clamp · pump current

One site · mixed sensors

FIG. 02
SITE · BTS-01 · LIVE
6 SENSORS · MIXED
WALK-IN FRIDGE
+4.2°C
range 2 … 6 °C
HOT WATER LOOP
62.4°C
range 60 … 75 °C
SERVER RACK A
23.6°C
range 18 … 28 °C
MEETING ROOM 2
820ppm
range 0 … 1000 ppm
WORKSHOP MAIN
7.4kW
range 0 … 12 kW
BASEMENT FLOOR
41%RH
range 30 … 65 %RH
POLL · 60s · HTTP / MQTT / LORAWAN
SHA · 7f3a-d2c1 · IMMUTABLE

How it gets installed

FIG. 03
STEP 01
Buy a sensor anyone sells

Shelly H&T for fridges and rooms, Aqara TH for retail floors, Efento NS-T for LoRaWAN runs, a clamp meter for energy. €15 to €60 each. We don't sell hardware and we don't lock you to one vendor.

STEP 02
Scan the QR

One scan provisions the device, gives it a token, and pairs it with a location. New channels self-register on the first sample, so a multi-probe sensor just appears in your dashboard with every reading.

STEP 03
Forget it exists

We log every minute, fire alarms on Telegram or email when readings break your rules, and keep a tamper-evident trail for at least two years. Inspectors, insurers and auditors get a PDF, not a binder.

Every event, in writing

FIG. 04
EVENT STREAM · ALL SITES
tail -f /var/log/opensense/events
WHY THIS MATTERS

Whoever shows up — a food inspector, a Legionella auditor, an insurer asking about that server-room fire — wants the same thing: a record they can prove was honest. Paper logs filled in retroactively fail that test the moment somebody asks.

OpenSense events are append-only, signed every minute, and exportable as a PDF that includes who acknowledged each alarm and what they did about it.

audit · append-only · signed

Pricing · one flat number

FIG. 05
TIER · TRIAL
€0
14 days · one site
  • // unlimited sensors
  • // telegram + email alerts
  • // last 7 days of history
no card required
TIER · STARTER
€29
/ month / site
cancel any time
  • // everything in trial
  • // 2-year audit retention
  • // one-click compliance PDF
  • // corrective-action workflow
first 10 pilot sites get year 1 free
TIER · TEAM
€89
/ month / org
up to 5 sites
  • // everything in starter
  • // roles + permissions
  • // API access + webhooks
  • // priority support sk/cz/en
5+ sites → talk to us

Send data in one HTTPS POST

FIG. 06
POST /v1/ingest
application/json
curl -X POST https://opensense.murzin.digital/v1/ingest \
  -H "Authorization: Bearer os_<device_token>" \
  -H "Content-Type: application/json" \
  -d '{
    "battery": 87,
    "readings": [
      { "channel": "t",   "value": 4.3   },
      { "channel": "h",   "value": 71.2  },
      { "channel": "co2", "value": 820   },
      { "channel": "p",   "value": 7.4   }
    ]
  }'
WIRE FORMAT
  • any channel: t / h / co2 / p / kw / leak / custom
  • idempotent retries via Idempotency-Key
  • channels self-register on first sample
  • out-of-range readings stored, flagged, never deleted
  • per-org rate limits, per-device tokens
  • TimescaleDB · continuous aggregates · 2-year retention floor
specs incomplete; api still moving

Built in Bratislava.
For everyone who measures something they'd hate to lose.

OPERATOR · solo founder
RESPONSE · within 24h
PILOT SLOTS · 10 OPEN