Terms of Use

1. Scope, contracting party, languages

These terms of use apply to the AirNode cloud service. Your contracting party is David Matthias Hübscher, Mittelstr. 12, 52379 Langerwehe, Germany (email: contact@air-node.net, contact form: https://air-node.net/en/kontakt), a sole trader; the full mandatory particulars are in the legal notice at https://air-node.net/en/impressum. Below, "we" means this contracting party and "you" means the user of the cloud service.

These terms apply to use of the cloud service through the web app at app.air-node.net, to pairing your AirNode devices with that service, and to programmatic access through the interface (API) under section 7. They become part of the contract when you accept them during registration (section 3). Deviating or supplementary terms of yours do not become part of the contract unless we expressly agree to their application in text form.

The contract language is German. Only the German version of these terms is binding. The English version is a courtesy translation; in case of discrepancy, the German version prevails.

2. Subject matter of the contract

The AirNode cloud service adds to the AirNode ventilation controller those functions a single device cannot provide on its own: a user account and management of the devices paired with it, access to your devices from outside your own network, a cross-device overview, long-term retention and presentation of your measurement series, alerts and notifications by email, triggering firmware updates remotely, and programmatic access under section 7. Which functions your device performs without the cloud service — in particular measurement, differential control, the weekly schedule, manual control, and the local web interface — is set out in detail in section 4.1 of the Support and Security Update Policy at https://air-node.net/de/support.

The cloud service is free of charge to you. There are no usage fees, no base fees, and no usage-dependent costs; these terms create no payment obligation. We do not reserve the right to place the functional scope described here behind a charge at a later date. Should an additional, paid offering arise in future, it would be a separate offering with its own contract formation; the services described here would remain unaffected. The cost of your internet connection and your end device is yours to bear.

The cloud service is provided without any assurance of a particular availability. Section 5 governs the details.

Not covered by these terms: the purchase of AirNode hardware (acquiring the devices is a separate contract of sale with its own terms — purchase price, delivery, warranty, any right of withdrawal, returns, and guarantees are governed by that contract and by statute; these terms therefore deliberately contain no withdrawal instructions and no distance-selling information about the hardware purchase); security updates for the device firmware (section 6); and the processing of personal data (section 12).

3. Formation of contract, registration, minimum age

The contract for use of the cloud service is formed when you create a user account, accept these terms, and we accept the registration. In every case you expressly accept these terms before the account comes into being; we record which version you accepted (section 10.5). There are two routes to creating an account: registration with an email address and a password, where you receive a confirmation link and the account is usable only once confirmed; or registration through an external sign-in service that we offer for the purpose, where we take your email address only where the service reports it as verified, you set no password, and the account is usable immediately — here too we separately ask for your acceptance of these terms and your acknowledgement of the privacy policy. If an account already exists under the same confirmed email address and you sign in through an external sign-in service, we link that sign-in to the existing account; this does not form a second contract. There is no entitlement to the conclusion of this contract.

On registration you provide an email address at which you can be reached, or we take it from your sign-in service. You keep your details up to date. An account is personal; using someone else’s account and passing on your means of sign-in are not permitted (section 4).

To create an account you must be at least 16 years old. If you are between 16 and 18, you may create and use an account only with the consent of a person with parental responsibility; we may require suitable evidence of the consent of those with parental responsibility where there is concrete doubt as to whether the required consent exists. Anyone under 16 may not use the cloud service. If we learn that an account was created contrary to this rule, we may suspend it and terminate under section 8.

An account is not required to operate the device: the AirNode also works entirely without a cloud connection, to the extent set out in section 4.1 of the Support and Security Update Policy at https://air-node.net/de/support. Anyone who does not create an account does not enter into this contract — and loses none of the functions that run on the device itself.

4. Your obligations when using the service

You keep your means of sign-in — your password, insofar as you have set one, access to any external sign-in service you use, and your API keys — such that third parties have no access to them, and you do not pass them on. If you suspect that a means of access has become known to a third party, change it without delay and inform us at contact@air-node.net. You are responsible for actions taken through your account or your API key for as long as you have not met this obligation; this does not apply to actions taken after you have notified us.

You use the cloud service only within applicable law and these terms. In particular, you refrain from pairing devices with your account over which you have no power of disposal; circumventing or defeating the service’s security measures, in particular authentication, the separation of rights between accounts, and the limits under section 7.3; querying the service automatically beyond what section 7.3 permits, extracting content in bulk, or loading it in a way that impairs its operation or others’ use of it; reselling, renting out, or otherwise providing access to the service or API keys to third parties, whether for payment or free of charge; examining or modifying the service’s software or the API in order to circumvent protective mechanisms, obtain access to other people’s accounts or data, or misuse the service; or introducing malware or processing third-party data without authorisation. Statutory entitlements remain unaffected, in particular the rights to correct errors, to make a backup copy, and to establish interoperability under §§ 69d and 69e of the German Copyright Act; the examination prohibition is directed solely at the purposes named above.

You ensure that you are entitled to transmit the data you bring into the service through your devices or your account, and that no third-party rights are infringed by it.

The cloud service serves operation, evaluation, and notification. It is not a safety device and not a monitoring system on which you may rely to avert danger — neither for people nor for buildings or property. Do not rely on a notification reaching you.

5. Availability, maintenance

We provide the cloud service with the care of a proper provider, but we give no commitment to any particular availability. There is no service level agreement, no assured percentage, no assured response or restoration time, and no contractual penalty for outages. We reserve the right to restrict or suspend the service temporarily where this is necessary for technical, operational, or security reasons. This is a deliberate statement and not a formality: the service is operated by a single individual on a small infrastructure. We do not commit to what we cannot demonstrably keep.

We may interrupt the service for maintenance, changes, and updates. Where possible, we announce plannable maintenance windows in advance in the app or by email and place them at times of low usage. In the case of security incidents, acute faults, and urgent security updates we may intervene without prior notice; in those cases we inform afterwards, so far as that is possible and reasonable for us.

At https://air-node.net/de/status we publish the platform’s operating status as measured by us. That page serves information purposes only. It creates no availability commitment, and we also give no commitment as to the availability of the status page itself or as to any particular currency or completeness of what it displays. What it displays rests on our own measurements and may contain gaps.

If the cloud service fails, your device continues to work to the extent described in section 4.1 of the Support and Security Update Policy at https://air-node.net/de/support. An outage of the service does not cause the device to stop controlling or to switch uncontrolled.

6. Updates and support period

Security updates for the device firmware, the question of what constitutes a security update, the delivery paths, and the declared support period are governed exclusively by the Support and Security Update Policy at https://air-node.net/de/support. The commitment declared there also applies within this contract; it is deliberately not repeated here, so that only one version of that commitment exists. What governs a device is the version of that policy published at the time of its purchase.

To be distinguished from this are changes to the cloud service. We continue to develop the service and may add to and change functions in doing so. For the withdrawal of functions, however, a limit of its own applies: as long as the support period is running for at least one device paired with your account, we do not take away the functions listed in section 2.1 — neither all at once nor step by step. We may change how one of those functions is provided, as long as it remains available to you in substance; if such a change affects you other than insignificantly, we announce it under section 10. Functions going beyond the scope described in section 2.1 may be discontinued with the announcement under section 10.

Section 9 applies to discontinuation of the service as a whole, and section 8.2 to our termination of your individual contract. Section 10.1 additionally makes clear that an essential element of the agreed principal obligations of the service cannot be withdrawn by way of a change to these terms either.

7. Programmatic access (API)

We also make the functional scope of the cloud service available through an interface (API). The API is part of the same service and the same contract; it does not create a separate contractual relationship. The machine-readable description of the interface refers to these terms.

Access is by means of either an access token from your signed-in session or an API key; you manage keys yourself through the service. An API key is personal and non-transferable. It belongs to your account, carries that account’s rights, and may not be passed on, published, or used jointly with third parties. Section 4.1 applies to all requests made with your key. This prohibition does not apply insofar as passing on or making available is required by statutory rights or obligations, in particular under Regulation (EU) 2023/2854 (Data Act). Insofar as statutory rights — in particular under Regulation (EU) 2023/2854 (Data Act) — require third-party access, we provide the legally required access in a suitable manner. Until a corresponding authorisation mechanism is introduced, this may also take the form of a documented manual procedure.

So that the interface remains usable for everyone, we limit the number of requests per unit of time. The limits that apply from time to time, how they are counted, and what happens when they are exceeded are stated in the published description of the interface. The applicable limits describe the technical capacity currently provided and do not constitute a guarantee of any particular volume of calls. We may change them; a change to your disadvantage will be announced under section 10. Independently of this, we may reject or delay individual requests where this is necessary to fend off an acute overload or a security incident.

We give a commitment that an endpoint will remain unchanged only for those endpoints expressly marked as stable in the description of the interface. For all other endpoints, for their data fields, and for their behaviour we give no stability commitment; they may change or disappear. Unaffected by this, the period under section 7.5 applies to a provided major version of the interface as a whole.

We announce non-backwards-compatible changes to a provided major version of the interface and its retirement at least 90 days before they take effect, by email to the address held in the account of every holder of a valid API key and in the description of the interface. During that period the affected major version remains available in its previous form. Changes that only fix errors, close security vulnerabilities, or add functions without breaking existing calls are not covered by this.

We may suspend or revoke an API key if it is used in a way that breaches section 4.2, in particular where the use impairs the service or others’ use of it; if there are concrete indications that the key has become known to third parties or is being used abusively; or if the associated account is suspended, terminated, or deleted. We inform you of a revocation without undue delay by email, stating the reason, unless exceptionally stating the reason would prejudice an investigation into a security incident; in that case we supply it subsequently. A new key can be created once the reason has ceased to apply. Revoking a key does not end the contract; section 8 governs suspension of the account.

8. Suspension and termination

You may end this contract at any time and without notice by requesting deletion of your account in the app. This is self-service and requires no notification to us. The deletion process, the grace period, and the handling of the associated data are governed by the privacy policy.

Our right of ordinary termination is limited as follows. As long as the support period declared under section 6 is running for at least one device you have paired with your account, we do not terminate your contract by ordinary termination — whether we would be ending the service for everyone or only for you. Outside that period — in particular for an account with no device paired to it, and after the support period has expired for all paired devices — we may terminate this contract in text form giving six weeks’ notice to the end of the month. The right to terminate for good cause remains unaffected in every case; good cause exists in particular where a ground for suspension under section 8.4 persists other than temporarily. Section 9, and not this termination rule, applies to discontinuation of the service as a whole.

Where there are concrete indications that your account or one of your means of access has been compromised, we may suspend without prior notice your account, individual functions, or an API key. Such a suspension is a protective measure in your interest and ours; it carries no allegation against you. We suspend only to the extent and for the duration necessary for protection, and lift the suspension as soon as the occasion has passed. A suspension does not delete your data.

We may suspend without prior notice your account, individual functions, or an API key if one of the following grounds exists: a use that endangers or substantially impairs the operation of the service or others’ use of it; a serious breach of section 4, or a breach of section 4 continued despite a prior warning; a use that breaches criminal law or substantially infringes third-party rights; or a statutory obligation or an administrative or judicial order requiring us to suspend. This list is exhaustive. We suspend only to the extent and for the duration necessary to remove the ground. A suspension does not delete your data.

We inform you of a suspension and its ground without undue delay afterwards by email to the address held in the account. We lift the suspension as soon as its ground has ceased to apply. You may at any time set out to us at contact@air-node.net circumstances that speak against the ground; we will then review the suspension again and inform you of the outcome.

9. Discontinuation of the free service

Whether and with what notice period we may discontinue the free cloud service, what we commit to in doing so, and how we announce a discontinuation are governed by section 6 of the Support and Security Update Policy at https://air-node.net/de/support. The commitment declared there also applies within this contract and is deliberately not repeated here: there should be only one version of that commitment, so that two differently worded promises do not stand side by side. When a discontinuation takes effect, this contract ends without any need for termination. Your device continues to work thereafter to the extent described in section 4.1 of that policy.

10. Changes to these terms

We may change these terms where there is an objective reason for doing so — in particular a change in the law or in the case law of the higher courts, an administrative or judicial order, a change or extension of the service, or the closing of a gap in the provisions. Changes that shift the balance of performance and consideration to your disadvantage, or that withdraw an essential element of the agreed principal obligations of the service, are not possible by this route.

We announce every change at least six weeks before the day it takes effect by email to the address held in the account. The announcement contains the changed wording or a reference where it can be retrieved, a comparison of the material changes, the date on which it takes effect, and the notice about the effect of your silence.

Your acceptance of an announced change is deemed given if you do not notify us of your rejection before the day it takes effect. We expressly draw your attention to this effect of your silence in the announcement. Rejection requires no particular form; email to contact@air-node.net suffices.

Up to the day on which the change takes effect you may terminate this contract free of charge and without notice — by rejecting the change or by deleting your account. This causes you no costs. If you terminate, the contract ends on the day the change would take effect, but at the latest when the deletion takes effect.

These terms carry a date as their version identifier. On registration we record which version you accepted. Earlier versions remain traceable through the version history (section 15).

11. Liability

We are liable without limitation for damage arising from injury to life, body, or health that rests on a breach of duty by us, our legal representatives, or our vicarious agents; for damage caused intentionally or by gross negligence by us, our legal representatives, or our vicarious agents; under the German Product Liability Act; and insofar as we have given a guarantee or fraudulently concealed a defect. The above limitations of liability do not apply insofar as liability is mandatory by law.

In cases of simple negligence we are liable only for breach of a cardinal obligation, and then limited in amount to the foreseeable damage typical of this type of contract at the time of conclusion. Cardinal obligations are those obligations whose fulfilment makes the proper performance of the contract possible in the first place and on whose observance you may regularly rely.

Any further liability is excluded. The above limitations also apply to the personal liability of our legal representatives and vicarious agents. The provisions of this section do not entail any change of the burden of proof to your disadvantage.

We do not invoke the mitigation of liability under § 521 of the German Civil Code (law of gift), even though the service is free of charge; the allocation above stands. The scope of our performance follows from section 2; under section 5 we assume no liability for the service being available at all times. Under section 5.4 the device’s control logic continues to run without the cloud service. The hardware itself and its installation are governed by the contract of sale under section 2.4 and by statute; this section restricts nothing there.

12. Data protection

How we process personal data — which data, for which purposes, on which legal basis, for how long, to which recipients, and with which rights for you — is set out exclusively in the privacy policy at https://air-node.net/de/datenschutz. These terms do not repeat its content; for all questions of processing the privacy policy alone governs, including where it changes independently of these terms. The contract concluded here is at the same time the contract on which the privacy policy relies where it bases a processing operation on Art. 6(1)(b) GDPR.

13. Rights in content and data

The measurements from your devices, your device and control settings, your schedules, and the other content you bring into the service remain yours. We acquire no ownership in them and no rights beyond section 13.2.

You grant us the simple, non-exclusive right, unrestricted as to territory and limited to the term of this contract, to store this data, process it technically, prepare it for your display, aggregate it for your account, and make it accessible to you and to the persons you authorise — in each case only so far as this is necessary to provide the service under section 2. This does not include any right to use your data for other purposes, in particular for advertising or for passing it to third parties for their own purposes; the privacy policy remains authoritative.

You may request and download the data stored about you in the service as an archive at any time. The scope of the export, its format, and its provision are governed by the privacy policy; the procedure also serves to fulfil your rights under Art. 15 and Art. 20 GDPR. Further rights of access to or provision of data that may follow from Union law remain unaffected.

The rights in the platform software, the device firmware, the web app, the website, and their design belong to us or to our licensors. These terms grant you only the right to use the service in accordance with the contract. We make the notices concerning the open-source components used and their licences separately available; for the component concerned, those licences take precedence over these terms.

14. Final provisions

The law of the Federal Republic of Germany applies. If you have your habitual residence in another state, this choice of law applies only insofar as it does not deprive you of the protection afforded by those provisions that cannot be derogated from by agreement under the law of your state of residence (Art. 6(2) of the Rome I Regulation).

We do not agree a place of jurisdiction with you as a consumer. The statutory rules on jurisdiction apply; in particular, you may sue us in the court with jurisdiction for your place of residence.

We are neither obliged nor willing to take part in dispute resolution proceedings before a consumer arbitration board. Your right to bring proceedings before the courts is unaffected. In the case of complaints, please first contact contact@air-node.net — we try to settle every matter directly.

We send notices under this contract to the email address held in your account. Keep that address up to date and reachable. Address your notices to us to contact@air-node.net or through the contact form at https://air-node.net/en/kontakt.

You may not transfer your rights and obligations under this contract to third parties without our consent. We may transfer the contract to a legal successor; in that case we inform you at least six weeks in advance, and you may end the contract free of charge before it takes effect. A transfer leaves the commitments under sections 6 and 9 unaffected; the legal successor takes them over.

If a provision of these terms is or becomes invalid or is not incorporated, the remainder of the contract stays valid. The statutory provisions take the place of the invalid or non-incorporated provision (§ 306 of the German Civil Code).

15. Version history

Version 1.0, 2026-07-27: First binding version.

Version 1.1, 2026-08-06: Changes in sections 3.3, 6, 7.2, 7.3, 8.3 to 8.5, 10.1 and 11.1.