Tractrix Cloud Terms of Service

Version 1.0-draftDraft prepared 30 September 2026

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These Terms of Service (“Terms”) govern access to and use of Tractrix Cloud, the online simulation service for airport planners provided Tractrix, including its web application, API and the cloud mode of the Tractrix CAD add-ins. They are business-to-business terms. The desktop software is licensed separately under the desktop software licence.

1. About these Terms

1.2 Acceptance and authority. You accept these Terms by ticking the acceptance box when you sign up or create an organisation, by signing an Order Form that references them, or by using the Service. If you accept on behalf of an organisation, you confirm that you have authority to bind it. If you do not have that authority, or do not agree, do not use the Service. An individual who creates an account without naming an organisation accepts these Terms for the workspace they create, and is treated as its Customer.

1.3 Order of precedence. If documents conflict, this order applies: (1) an Order Form signed by both parties, but only for the specific Customer and matter it addresses; (2) the Data Processing Addendum (“DPA”), for anything concerning personal data; (3) these Terms; (4) the Acceptable Use Policy and the Service Level Agreement; (5) the Documentation. Terms on a Customer purchase order or supplier portal do not apply, even if accepted by clicking.

2. Definitions

Account: An individual user's login to the Service.
Admin: A User with the admin or owner role in an Organisation.
Affiliate: An entity that controls, is controlled by or is under common control with a party, where control means owning more than 50% of the voting interests.
API Token: A personal access token (beginning tx_) that lets software act as a User in one Organisation.
Beta Feature: A feature or service marked Preview, Beta, Early Access or similar.
Customer Data: All data, files and content submitted to the Service by or for the Customer, including projects, drawings, simulation requests and their parameters, and personal data of Users contained in them, and the Outputs.
Documentation: The user manuals, API and protocol documentation and help pages published on the Tractrix website, as updated from time to time.
Fees: The amounts payable for a paid Plan, as stated on the pricing page or in an Order Form.
Open-Source Components: Software provided under an open-source licence, including the OpenAirside engine licensed under GPL-2.0-or-later.
Order Form: An ordering document or online checkout that specifies a Plan, Subscription Term, Fees or other commercial terms and references these Terms.
Organisation: A workspace in the Service to which Users, projects and API Tokens belong.
Outputs: Results generated by the Service from Customer Data, including swept paths, clearance envelopes, conflict checks, jet-blast contours, reports and exports.
Plan: The Community, Professional or Enterprise plan, or another plan we offer, with the limits described on the pricing page or in an Order Form.
Service: Tractrix Cloud, including the web application, the API, the cloud engine used by the CAD add-ins, and related support, excluding Open-Source Components as licensed to you under their own licences.
Subscription Term: The period for which a paid Plan is purchased, including renewals.
User: An individual authorised by the Customer to use the Service under its Organisation, such as an employee or contractor.

3. Accounts and organisations

3.1 Eligibility. The Service is for professional use by organisations and by individuals aged 18 or over acting in a business or professional capacity.

3.2 Account information. You must give accurate information, keep it up to date and verify your e-mail address. Each Account is for one named individual; Accounts may not be shared.

3.3 Roles and Admins. Organisations have owners, admins, members and viewers with the permissions described in the Documentation. The Customer is responsible for choosing its Admins, for the Users they invite, for the roles they grant, and for removing Users who should no longer have access.

3.4 Seats. Each User and pending invitation counts as a seat against the Plan limit. Seats may be reassigned when a User leaves, but not shared or rotated to avoid the limit.

3.5 Responsibility for Users. The Customer is responsible for its Users' compliance with these Terms and for all activity under its Organisation, except activity caused by our breach.

3.6 Organisations invited by a third party. If you join an Organisation owned by another customer (for example a client or consultant), that customer controls the Organisation and its content, and may remove you or change your role.

4. Plans, fees, taxes, renewal and cancellation

4.1 Plans and limits. Plan limits (runs per month, projects, seats, API Tokens, drawing size) are shown on the pricing page or in the Order Form. When a limit is reached, the Service refuses the action and explains which limit applies; nothing is deleted or blocked retroactively.

4.3 Taxes. Fees exclude VAT, GST, sales and similar taxes, which the Customer pays in addition unless it provides a valid exemption or the reverse-charge mechanism applies. Each party bears its own income taxes. If withholding tax applies, the Customer grosses up the payment so that we receive the full Fee, unless the parties agree otherwise in an Order Form.

4.4 Renewal. Paid Subscription Terms renew automatically for successive periods equal to the initial term (or one year, if longer than one year) unless either party gives notice of non-renewal before the end of the current term — through the Plan & usage page or by e-mail at least 30 days before renewal for invoiced plans. We will remind you before an annual renewal where the law requires it, and at least 30 days in advance for any annual renewal.

4.5 Price changes. We may change Fees for a renewal term by giving at least 60 days' notice before the renewal. Fees do not change during a paid Subscription Term.

4.6 Upgrades, downgrades and cancellation. Upgrades take effect immediately and are pro-rated. Downgrades and cancellations take effect at the end of the current billing period. Except as stated in these Terms or required by law, Fees are non-refundable. If we terminate for convenience, discontinue the Service, or you terminate for our uncured material breach, we refund prepaid Fees for the remaining unused period.

4.7 Late payment. Undisputed overdue amounts may bear interest at the lower of 1% per month and the maximum rate allowed by law, and, after 14 days' written notice, we may suspend paid features (not access to export Customer Data). Parties will discuss disputed invoices in good faith.

4.8 Consumers. The Service is intended for business customers. If mandatory consumer-protection law nevertheless applies to you (for example a statutory right to withdraw from a distance contract within 14 days, or rules on automatic renewals and cancellation), nothing in these Terms limits those rights; see section 27.

5. Community plan, trials, previews and Beta Features

5.1 Community plan. The Community plan is free, subject to its limits. We may change its limits or features, or end it, with at least 30 days' notice, and you may export your Customer Data during that period.

5.2 Trials. A free trial of a paid Plan lasts for the period stated when it starts. At its end the Organisation returns to the Community plan unless you choose a paid Plan. We will never charge you at the end of a trial unless you have expressly agreed to that in advance.

5.3 Preview and Beta Features. Tractrix Cloud is currently in preview. Preview and Beta Features are provided for evaluation; they may change or be withdrawn, may be less reliable, are excluded from any service-level commitment, and are provided “as is”. Our total liability for them is limited as stated in section 14.4.

6. Customer Data

6.1 Ownership. As between the parties, the Customer owns all Customer Data, including Outputs. We acquire no rights in Customer Data except the licence in section 6.2.

6.2 Licence to process. The Customer grants us a worldwide, non-exclusive, royalty-free licence, for the duration of these Terms and the exit period in section 19, to host, copy, transmit, process and display Customer Data only as needed to provide, secure and support the Service, to comply with law, and as otherwise instructed by the Customer. This licence extends to our sub-processors as needed for those purposes.

6.3 No other use. We do not use Customer Data to train machine-learning models, to build products for others, for advertising, or for any purpose other than those in section 6.2. We may create and use aggregated, de-identified statistics about use of the Service (for example numbers of runs, run durations, error rates, aircraft types chosen) that do not identify the Customer, any individual or any airport or project, to operate and improve the Service.

6.4 Personal data. Where Customer Data contains personal data, the DPA applies and forms part of these Terms.

6.5 Customer responsibilities. The Customer is responsible for the accuracy, quality and legality of Customer Data and for having all rights, consents and authorisations needed to upload it and to let us process it — including rights in third-party drawings, survey data and airport data provided by an airport operator or authority.

6.7 Backups. We back up the Service as described in the security overview, but the Service is not a records-management or archival system. The Customer should keep its own copies of important Customer Data, which it can export at any time.

7. Confidentiality

7.1 Definition. “Confidential Information” means non-public information disclosed by one party to the other that is marked confidential or that a reasonable person would understand to be confidential. Customer Data is the Customer's Confidential Information. It excludes information that is or becomes public without breach, was lawfully known to the recipient without restriction, is received from a third party without a duty of confidence, or is independently developed.

7.2 Obligations. The recipient will use the other party's Confidential Information only to perform or exercise rights under these Terms, protect it with at least reasonable care (and no less care than its own similar information), and disclose it only to its and its Affiliates' employees, contractors, sub-processors and advisers who need to know and are bound by confidentiality obligations at least as protective.

7.3 Critical-infrastructure data. We recognise that Customer Data may describe critical infrastructure. Our personnel access Customer Data only when needed to provide support requested by the Customer, to maintain or secure the Service, or to comply with law; such access is limited to authorised personnel, is logged where technically possible, and is subject to confidentiality undertakings. We do not disclose Customer Data to other customers or publish it in examples, case studies or test suites without written consent.

7.4 Compelled disclosure. If the law or a court or authority requires disclosure, the recipient will, where legally permitted, give prompt notice and reasonable assistance so the other party can seek protection, and disclose only what is legally required. Our approach to government requests for Customer Data is set out in the DPA.

7.5 Duration. These obligations continue for five years after termination and, for Customer Data and trade secrets, for as long as they remain confidential.

8. Acceptable use and Customer responsibilities

The Customer and its Users must comply with the Acceptable Use Policy and applicable law, must not resell, sublicense or provide the Service to third parties as a service bureau except as allowed by an Order Form, and must not circumvent Plan limits, rate limits or security controls. Nothing in this section restricts rights granted by the licence of an Open-Source Component (see section 16).

9. API Tokens and security responsibilities

9.1 Tokens. API Tokens act with the live role of the User who created them in one Organisation. Each token is shown once; we store only a hash and cannot recover it.

9.3 Our responsibilities. We implement and maintain the technical and organisational measures described in Annex II of the DPA, and will not materially reduce the overall level of security during a Subscription Term.

10. Service levels and support

10.3 Changes to the Service. We may improve and change the Service. We will not make a change that materially reduces the core functionality of a paid Plan during its Subscription Term without the Customer's consent, except where required by law or for security. We will give at least 90 days' notice before discontinuing the Service or a material feature, except where that is impossible for legal or security reasons.

10.4 Engine versions. Each run records the engine version used. Engine updates may change results for the same input; the Customer should re-run and review analyses that it relies on after an update.

11. Suspension

We may suspend access by a User, API Token or Organisation, in whole or in part, if reasonably necessary to: prevent or respond to a security threat or unauthorised access; stop a material breach of the Acceptable Use Policy; comply with law, a court order or sanctions; or, after notice under section 4.7, address unpaid Fees. We will limit the suspension to what is necessary, give notice beforehand where practicable (and otherwise promptly afterwards) with the reason, and restore access once the cause is resolved. Suspension does not affect the Customer's right to export its Customer Data unless the law prohibits it.

12. Engineering and professional-use disclaimer

12.1 Planning aid. The Service and its Outputs are planning aids for use by qualified professionals. They are not certified design tools, have not been approved by any aviation authority, and do not replace the aircraft manufacturer's airport planning documents, the applicable standards (for example ICAO Annex 14 and associated manuals, FAA advisory circulars, EASA certification specifications or national regulations), or professional engineering judgement.

12.2 Known limitations. Outputs are computed with a kinematic model that does not model tyre scrub, differential thrust, braking, wind, pavement condition or pilot technique; some aircraft geometry is estimated from public data (the FAA Aircraft Characteristics Database) and flagged as such; jet-blast contours are indicative empirical estimates; standards values are transcribed by us and may contain errors or be superseded. Details are in the Engineering disclaimer and the methodology.

12.3 Customer verification. The Customer is solely responsible for (a) checking that inputs (aircraft type, geometry, units, coordinate system, speeds and parameters) are correct; (b) having Outputs reviewed and verified by suitably qualified engineers against the manufacturers' manuals and the standards and regulations applicable to the aerodrome before relying on them for design, approval, construction or procurement; and (c) all design decisions and submissions to authorities.

12.4 No operational use. The Service must not be used for real-time or operational purposes, including air traffic control, apron management, surface movement guidance, aircraft or vehicle guidance, pilot or driver instruction, or any application where its failure or inaccuracy could directly lead to death, personal injury, or damage to aircraft or property.

13. Warranties and disclaimers

13.1 Mutual. Each party warrants that it has the authority to enter into these Terms.

13.2 Our warranties. For paid Plans, we warrant that during the Subscription Term (a) the Service will perform materially in accordance with the Documentation, and (b) we will not materially reduce its security or its core functionality. If we breach this warranty, the Customer's remedy is for us to use reasonable efforts to correct the non-conformity and, if we cannot do so within 30 days of notice, for the Customer to terminate the affected subscription and receive a refund of prepaid Fees for the remaining period.

13.3 Customer warranties. The Customer warrants that it has the rights needed for Customer Data under section 6.5 and that its use of the Service complies with applicable law, including export-control and sanctions law.

13.4 Disclaimer. Except as expressly stated in these Terms, and to the maximum extent permitted by law, the Service, the Outputs, Beta Features and the Community plan are provided “as is” and “as available”, and we disclaim all other warranties, conditions and representations, express or implied, including those of merchantability, satisfactory quality, fitness for a particular purpose, accuracy, non-infringement and uninterrupted or error-free operation. In particular, we do not warrant that any Output complies with any standard, regulation or manufacturer's requirement, or that it is suitable for any specific aerodrome, aircraft or project.

14. Limitation of liability

14.1 Excluded losses. Subject to section 14.3, neither party is liable, whether in contract, tort (including negligence), breach of statutory duty or otherwise, for any: loss of profits, revenue, business, contracts or anticipated savings; loss of goodwill; indirect, consequential, special or punitive loss; or costs of procuring substitute services; nor, in the case of Tractrix, for any loss arising from design, construction, procurement or operational decisions taken in reliance on Outputs that were not independently verified as required by section 12.3.

14.3 Unlimited liability. Nothing in these Terms excludes or limits liability for: death or personal injury caused by negligence; fraud or fraudulent misrepresentation; wilful misconduct or, where the governing law does not allow it to be limited, gross negligence; the Customer's obligation to pay Fees; a party's indemnity obligations under section 15; the Customer's breach of section 20 (export control and sanctions); or any other liability that cannot be limited or excluded by law.

14.5 Allocation of risk. The Fees reflect this allocation of risk, which is an essential basis of the bargain. Where a limitation is unenforceable in part, it applies to the maximum extent permitted.

15. Indemnities

15.1 Tractrix. We will defend the Customer against any third-party claim alleging that the Service, as provided by us and used in accordance with these Terms, infringes that third party's patent, copyright or trademark or misappropriates its trade secret, and will pay damages and costs finally awarded or agreed in settlement. This does not apply to claims arising from Customer Data; Open-Source Components used under their own licences (for which the licence terms apply); combination with items we did not provide; modifications not made by us; or use after we have offered a non-infringing alternative. If a claim is made or likely, we may procure the right for the Customer to continue using the Service, modify it to be non-infringing with materially equivalent functionality, or, if neither is commercially reasonable, terminate the affected subscription and refund prepaid Fees for the remaining period. This section states our entire liability for third-party infringement claims.

15.2 By the Customer. The Customer will defend Tractrix and its Affiliates against any third-party claim arising from (a) Customer Data, including a claim that it infringes rights or was uploaded without authorisation; (b) use of the Service in breach of the Acceptable Use Policy or section 20; or (c) a design, project or operation in which the Customer used Outputs, except to the extent the claim arises from our breach of these Terms — and will pay damages and costs finally awarded or agreed in settlement.

15.3 Procedure. The indemnified party must promptly notify the claim (delay relieves the indemnifying party only to the extent it is prejudiced), give sole control of the defence and settlement to the indemnifying party (no settlement may impose an admission or obligation on the indemnified party without its consent, not unreasonably withheld), and provide reasonable cooperation at the indemnifying party's expense.

16. Intellectual property and open source

16.1 Our rights. Tractrix and its licensors own the Service, the Documentation, the Tractrix marks and all related intellectual property. Subject to these Terms, we grant the Customer a non-exclusive, non-transferable right during the Subscription Term for its Users to access and use the Service for the Customer's internal business purposes, including preparing deliverables for its own clients.

16.2 Open source. The simulation engine used by the Service (OpenAirside / tractrix-engine) and the Tractrix desktop products are free software licensed under the GNU General Public License, version 2 or later. Nothing in these Terms restricts any right you have under the GPL or another open-source licence in the software you receive under it; where these Terms conflict with such a licence for that software, the licence prevails. The restrictions in these Terms apply to the hosted Service as a whole (our servers, accounts, infrastructure and non-open-source web components), not to your copies of open-source software. See Licences.

16.3 Outputs. The Customer may use Outputs for any lawful purpose, subject to section 12 and to any third-party rights in the Customer's own inputs. Outputs may include CAD layer names, styles and report templates provided by us, which we license to the Customer royalty-free and perpetually for use with those Outputs.

17. Feedback

If you give us suggestions, bug reports or other feedback, we may use them without restriction or payment, but we will not identify you or disclose your Confidential Information in doing so. Contributions to the open-source project on GitHub are governed by the project's contribution terms and licence, not by this section.

18. Term and termination

18.1 Term. These Terms apply from acceptance until all subscriptions have ended and the Customer's Organisations have been deleted.

18.2 Termination by the Customer for convenience. The Customer may stop using the Service and delete its Organisation at any time. For paid Plans, cancellation takes effect at the end of the current billing period and prepaid Fees are not refunded, except as stated in section 4.6 or required by law.

18.3 Termination for cause. Either party may terminate these Terms or an affected subscription by written notice if the other party (a) materially breaches them and does not cure the breach within 30 days of notice, or (b) becomes insolvent, enters administration, liquidation or a similar procedure, or ceases business.

18.5 Effect. On termination, the Customer's right to use the Service ends, subject to the exit period in section 19; each party returns or destroys the other's Confidential Information; and the Customer pays Fees due up to the effective date. Sections 6.3, 7, 12, 13.4, 14, 15, 16.2, 17, 19, 25, 26 and 27 survive.

19. Data export, portability and switching

19.1 Export at any time. During the Subscription Term the Customer can export its Customer Data at no extra charge: drawings as GeoJSON, run requests and results as JSON, Outputs as GeoJSON, DXF, CSV and HTML reports, and account data as JSON through Settings → Privacy. These are structured, commonly used and machine-readable formats, and the tractrix/1 protocol and the engine are openly documented, so exported requests can be re-run with the open-source engine.

19.2 Exit period. After termination or expiry, the Customer has a data retrieval period of at least 30 days during which it can export its Customer Data. At the end of that period we delete Customer Data from the live Service, and it is removed from backups within the backup cycle described in the DPA, unless the law requires us to keep it. On request we will confirm deletion in writing.

19.3 Switching under the EU Data Act. Where Chapter VI of Regulation (EU) 2023/2854 (the Data Act) applies to the Customer's use of the Service, and without limiting sections 19.1 and 19.2:

the Customer may request to switch to another provider of data processing services, or to on-premises infrastructure (for example the open-source engine), or to erase its exportable data, by giving notice of at most two months;
after that notice, a transitional period of up to 30 calendar days applies, during which we will provide reasonable assistance, act with due care to maintain business continuity, continue to provide the Service, and provide clear information about known risks to continuity. If this period is technically unfeasible, we will tell the Customer within 14 working days of the request, give reasons, and propose an alternative transitional period of no more than seven months. The Customer may extend the transitional period once, for a period it considers more appropriate;
the exportable data comprises all Customer Data (inputs and Outputs) and the metadata created by the Customer's use of the Service, such as project structure, run parameters, engine versions and timestamps. Data specific to the internal functioning of the Service whose export would risk a breach of our trade secrets (for example our infrastructure configuration and security logs other than the Customer's audit log) is excluded;
a data retrieval period of at least 30 calendar days follows the transitional period;
after the retrieval period, or once switching is complete, we will fully erase the exportable data and digital assets generated directly by the Customer, and confirm that erasure;
the contract ends, and the Customer is notified, once switching has been completed successfully (or, if the Customer only wants its data erased, at the end of the notice period);
switching charges: we do not charge for switching or data egress. In any event, from 12 January 2027 no switching charges may be imposed, and before then any charges may not exceed the costs directly linked to the switching process;
we provide the information required by Article 26 of the Data Act, including procedures, formats and known restrictions, in the Tractrix Cloud manual and on request, and will cooperate in good faith with the destination provider.

Counsel: confirm how the Art. 31(2) exemption for non-production versions supplied for a limited period interacts with the free Community plan and trials; the draft applies the switching rights to all plans.

20. Export control and sanctions

21. Anti-bribery and compliance

Each party will comply with applicable anti-bribery and anti-corruption laws, including the UK Bribery Act 2010 and the US Foreign Corrupt Practices Act, and will not offer, give, request or accept any bribe or improper payment in connection with these Terms. Each party will comply with applicable modern-slavery legislation.

22. Publicity

We will not use the Customer's name, logo or trademarks, or identify any airport or project of the Customer, in marketing, customer lists, case studies or press releases without the Customer's prior written consent, which it may withdraw at any time for future use. The Customer may state that it uses Tractrix.

23. Force majeure

Neither party is liable for delay or failure to perform (other than payment obligations) caused by events beyond its reasonable control, such as natural disasters, epidemics, war, terrorism, riots, acts of government, failures of public networks or power, or large-scale attacks on internet infrastructure that could not reasonably have been prevented, provided it notifies the other party promptly and uses reasonable efforts to mitigate. If such an event prevents performance for more than 30 days, either party may terminate the affected subscription, and we will refund prepaid Fees for the remaining period.

24. Assignment and subcontracting

Neither party may assign these Terms without the other's written consent (not unreasonably withheld), except to an Affiliate or to a successor in a merger, acquisition or sale of all or substantially all of the relevant business or assets, with notice to the other party, provided the successor is not a competitor of, or sanctioned in relation to, the other party. We may use subcontractors and sub-processors, and remain responsible for their performance; sub-processors are governed by the DPA.

25. Notices

26. Governing law and disputes

26.2 Escalation. Before starting proceedings, the parties will try to resolve a dispute by escalation to senior representatives for 30 days, except where urgent injunctive relief is needed.

Counsel: choose one option, possibly by Customer region — (a) the courts of England and Wales with English law; (b) the courts of Ireland with Irish law, for EEA customers; (c) the state and federal courts of Delaware or New York with that state's law, for US customers; (d) arbitration under the LCIA, ICC or SIAC rules, seated in London, Paris or Singapore, one arbitrator, in English — useful for customers in jurisdictions where foreign judgments are hard to enforce (New York Convention); (e) the law and courts of the country where Tractrix is incorporated. Either party may seek interim relief in any competent court.

27. Consumers and mandatory law

These Terms are designed for business customers. If you use the Service as a consumer, you have the benefit of any mandatory protections of the law of the country where you live, which these Terms do not limit — including statutory rights of withdrawal, statutory guarantees, and rights in relation to digital content and services — and you may bring proceedings in the courts of that country. Nothing in these Terms excludes or limits any right or liability that cannot be excluded or limited by law.

28. Changes to these Terms

We may update these Terms to reflect changes in the Service, the law or our business. We will notify Customers of material changes by e-mail to Organisation owners and in the Service at least 30 days before they take effect (or earlier where required by law or for security reasons, in which case we will explain why). If the Customer objects to a material change, it may terminate the affected paid subscription before the change takes effect and receive a refund of prepaid Fees for the remaining period; otherwise, continued use after the effective date constitutes acceptance. Changes do not apply to a signed Order Form during its term unless both parties agree. Users may be asked to accept the new version when they next sign in. Previous versions are listed in the change log.

29. General

Entire agreement. These Terms, with the documents listed in section 1.4 and any Order Form, are the entire agreement between the parties about the Service and supersede prior agreements on that subject. Neither party relies on any statement not set out in them, but nothing limits liability for fraudulent misrepresentation.

Independent parties. The parties are independent contractors. Nothing creates a partnership, agency or employment relationship.

Third parties. No one other than the parties has a right to enforce these Terms, including under the UK Contracts (Rights of Third Parties) Act 1999, except the Affiliates indemnified under section 15.

Waiver and severability. A failure to enforce a provision is not a waiver. If a provision is held invalid, it is modified to the minimum extent necessary and the rest remains in force.

Language. These Terms are written in English. If translated, the English version prevails to the extent permitted by law.