Indoor Air Quality APIs: Compare Monitors and Platforms

Compare indoor air quality monitors and platforms by API access, data export, required subscriptions, and documented costs. See which options provide local or cloud access, what measurements you can retrieve, and what to verify before buying.

This guide compares published product documentation. We have not independently tested these systems unless a page explicitly describes a test.

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What is an indoor air quality API?

An indoor air quality API lets software retrieve measurements from a supported monitoring system. Access may come from a device on your local network or from the vendor’s cloud. Many APIs expose readings from equipment you own or are authorized to access; they do not provide indoor measurements for any address.

The qualifications matter in practice. AirGradient documents a local endpoint on the monitor itself alongside a token-based cloud API. Airthings issues API clients only to administrators of an Airthings for Business account; a client is mostly limited to the account where it was created, and the authorization-code flow reaches the accounts the signing-in user can access. Kaiterra restricts devices in an organization to that organization’s API keys, and tells owners to treat device IDs as secrets. AirGradient’s public indoor dataset covers only owners who opted in, with coordinates rounded before publication, so it is not a way to read an arbitrary building.

Which indoor air quality API setup fits your project?

There is no overall winner. The right choice depends on where the data has to go, who maintains the integration, and which sensors you need. These are conditional suggestions based on what each vendor documents.

Small monitoring projects

If you want a few monitors and can run a small script, AirGradient ONE has a published hardware price and a local JSON endpoint, but its local endpoint returns current values only, and the product page leaves open what dashboard and API access costs after 12 months. Atmocube costs more per device but publishes its cloud API price (PRO, per device per year) and offers more sensors on some SKUs. If you need neither local access nor published prices, the commercial options below may still fit a small pilot; ask about minimum orders.

Commercial multi-site deployments

Airthings for Business is built around hosted, multi-building management with OAuth2, published rate limits, webhooks and MQTT, but no local access is documented and its terms prohibit selling data. Kaiterra Sensedge Mini combines a cloud history API with on-device BACnet/IP and Modbus RTU, which suits buildings with an existing BMS, but BACnet needs an enterprise licence and all prices are quote-only. Both require an active subscription for full API access.

Local access without a vendor cloud

AirGradient exposes current readings over HTTP on your network. Atmocube offers Modbus TCP/RTU, publishing to an MQTT broker you run, and CSV logging to a USB drive, without a subscription. Kaiterra offers BACnet/IP (with an enterprise licence), Modbus RTU and on-premises MQTT. None of these is a local history API: apart from Atmocube’s USB CSV files and short on-device buffers, history kept locally is history you store yourself. No local access is documented for Airthings for Business.

Cloud integrations

For cloud-to-cloud integration, Airthings documents the most operational detail (rate limits, pagination, webhooks). Kaiterra documents history aggregation and strict UTC handling but no numeric rate limits. AirGradient’s API limits past-measure requests to 10-day windows. Atmocube’s REST reference did not render during our review, so confirm endpoints before committing.

If none of these is clearly right, answer the questions below first. They usually decide the choice faster than a feature list.

Local access, cloud APIs and indoor air quality data export

Local access depends on your network

A local interface (an HTTP endpoint, Modbus, BACnet or a local MQTT broker) works only where your software can reach the device on the same network or bus. It can work without a vendor cloud account, though some local features have their own licence conditions (Kaiterra’s BACnet requires an enterprise licence), and it usually returns current values. A local protocol is also not the same as a local REST API: Modbus registers and BACnet objects need building-automation software or a gateway, not a web client.

Cloud APIs depend on an account, and usually a plan

A cloud API reads data the vendor has already collected. That gives you history and multi-site access without running servers, but it depends on the account staying active. Of the four setups here, Airthings, Atmocube and Kaiterra tie full API access to a paid plan, and AirGradient’s post-12-month terms are unclear. A free dashboard account is not the same as a free API.

A current-readings endpoint is not historical storage

An endpoint that returns the latest reading does not keep history for you. If you poll a local endpoint, you need a database and someone to maintain it. Cloud history endpoints have their own limits: request windows, page sizes, aggregation intervals and retention periods, which vendors often do not publish.

CSV export versus API access

Dashboard CSV export suits occasional reports and audits. It is manual, and some vendors send files by email. An API suits continuous integration. Check whether CSV export survives a lapsed subscription: on Airthings’ Limited plan, data download is not available.

Polling limits and who maintains the integration

Rate limits decide how many devices you can poll and how often. Airthings publishes 5,000 requests per hour per client; the others do not publish numbers. Push options such as webhooks and MQTT reduce polling, but someone still has to monitor failures. Airthings webhooks, for example, are not retried.

Out of scope: public datasets and outdoor AQI APIs

Public indoor datasets contain only locations whose owners chose to share. Outdoor air-quality APIs report ambient conditions near an address, not conditions inside a specific building. Neither replaces a monitor in the space you care about.

Questions to ask before buying

• Can I retrieve the parameters I need? Check the exact model, not the brand. Confirm whether VOC is a concentration or an index, and whether CO2 is measured by an NDIR sensor.
• Is access local, cloud or both? And which protocol: REST, MQTT, Modbus or BACnet.
• What remains available if a subscription ends? Ask about the dashboard, API, export and stored history separately.
• How far back can I export? Ask about retention, request windows and aggregation.
• Are API limits suitable for the deployment? Multiply devices by polling frequency and compare with the published limit, or ask for one.
• Who can access the data? Ask how keys are scoped, who can create them, and how they are revoked.
• What extra hardware is required? Gateways, hubs, power supplies, PoE switches or BACnet gateways.
• Which reuse rights are documented? Reading data through an API does not give permission to resell or redistribute it.

Already own a monitor?

If you already own a monitor, start with its official API and support documentation. Our profiles link to those resources. A setup or troubleshooting question is different from selecting a new system.

• AirGradient ONE: Where do I access the API documentation, API token and local API? · AirGradient Sensor API v1 specification (Swagger) · Support: Where do I access the API documentation, API token and local API?
• Airthings for Business: API getting started · API authorization · Support: Business Dashboard CSV export
• Atmocube: Cloud dashboard API · Modbus setup guide · Support: Atmocube help center collection
• Kaiterra Sensedge Mini: Kaiterra API reference · Can I integrate the data to my existing BAS or BMS? (Sensedge Mini) · Support: How can I view and export the data on the Sensedge Mini?

Indoor Air API Guide does not provide manufacturer support. For device problems, contact the manufacturer.

Indoor air quality API FAQs

Do I need to buy sensors to use an indoor air quality API?

For a specific building, yes. The APIs compared here return readings from monitors on the account or network you control. Public datasets cover only locations whose owners opted in.

Is an outdoor air-quality API a substitute for indoor measurements?

No. Outdoor APIs describe ambient air near a location. Indoor CO2, VOCs and particles depend on occupancy, ventilation and sources inside the space.

Can I export data without a subscription?

It depends on the setup. Atmocube can log CSV to a USB drive and provide Modbus and MQTT without a plan; its free Basic dashboard keeps 30 days of cloud data, and the plan table lists historical data export. AirGradient’s local endpoint needs no account but gives current values only. Airthings’ Limited plan removes data download, and Kaiterra’s terms end dashboard and API rights when the subscription lapses.

Does API access allow me to resell the data?

Not by default. Airthings and Atmocube terms prohibit selling data obtained through their products or services, and Kaiterra’s terms prohibit re-serving API data to third parties. AirGradient’s terms are less specific. Read the current terms and ask the vendor in writing.

Can these monitors confirm mold or establish that a building is safe?

No. These monitors measure parameters such as CO2, particles, VOCs, temperature and humidity. Some platforms calculate risk indicators, but general air quality readings do not detect or confirm mold growth, and they do not certify that a building is safe or healthy. Use a qualified professional for inspections or health concerns. This guide is not medical or safety advice.

How this guide was researched

Researched and edited by Justin Carlson. Reviewed November 7, 2026.

We read each vendor’s product pages, developer documentation, support articles, pricing and terms, and recorded every material claim with its source and checked date. We have not tested these systems hands-on, and vendors have not reviewed these pages. Unknowns are marked as unknown rather than filled in. Read the full methodology.

Found an error or a change? Send a correction.

Disclosure: The editor, Justin Carlson, co-founded and leads Invivus Technologies, which runs Moldmap, SensiReport and Moldlist and is developing Aerlume, an indoor mold sensor. He has no financial relationship with AirGradient, Airthings, Atmocube or Kaiterra, no vendor pays for coverage or placement, and the site has no affiliate links. How relationships are handled.