Terms of Use — EnginAIer

1. Who we are

Digital Thread AI ("Digital Thread AI", "we", "us") is the company behind EnginAIer. EnginAIer is the software and service; Digital Thread AI is the party you are contracting with. These Terms of Use ("Terms") are an agreement between you and Digital Thread AI, and govern your use of the EnginAIer desktop application, the local connector it installs, the CAD and BIM plugins it loads, the EnginAIer website, and the EnginAIer cloud service (together, the "Service").

[PLACEHOLDER 1 — registered legal name and company number.] Insert Digital Thread AI's full registered legal name including its legal form (for example "Ltd", "LLC", "Inc.", "Pty Ltd" — the correct form is not yet confirmed and must not be guessed) together with its company registration number and the register it is recorded in.

[PLACEHOLDER 2 — registered address.] Insert Digital Thread AI's registered postal address. This is required for EU and UK consumers and is the address used to identify the controller in the Privacy Policy.

By creating an account, by accepting these Terms during installation of the software, or by using the Service, you agree to these Terms and to the Privacy Policy, which forms part of this agreement. If you are agreeing on behalf of a company or other organization, you confirm that you have authority to bind it, and "you" means that organization.

Neither Digital Thread AI nor EnginAIer is affiliated with, endorsed by, or sponsored by Autodesk, Inc., Bentley Systems, Trimble, Robert McNeel & Associates, or any other software vendor whose products the Service can work with. All trademarks are the property of their respective owners.

2. What the service does

EnginAIer is an AI assistant for CAD and BIM work. You install a desktop application on a Windows machine. It runs a local connector, which loads plugins into the CAD software you already own and licence, and communicates with them over Windows named pipes on that machine. Supported products currently include Autodesk Civil 3D, Revit, Navisworks and Dynamo, Bentley OpenRoads Designer, Trimble Tekla Structures, and Rhino with Grasshopper.

You describe what you want in plain language. The assistant plans the work and calls tools that operate on your drawings and models. Those tool calls execute on your own machine. The Service does not upload your drawings or models in order to work on them.

The Service depends on software, licences and hardware you provide. We do not supply CAD licences, and we are not responsible for the behaviour, availability or licensing terms of third-party CAD software.

3. Where your data goes

This split is central to the Service and to your obligations under it. The Privacy Policy describes it in full; in summary:

Stays on your machine. Your drawings, models, and CAD data. The connector reads and writes them locally through the CAD software's own APIs. Uploaded templates, layout samples and PDFs, and your chat history, are written to a data folder on whichever machine runs the connector — for a desktop customer, that is your own computer.
Goes to the cloud. The text of each conversation turn — your messages, the assistant's replies, and the results of tool calls that the assistant needs in order to continue. The connector sends these to the EnginAIer cloud service, which calls Anthropic using EnginAIer's own API key and returns the response. Anthropic acts as a subprocessor. Your account details, billing data and usage metering also live in the cloud.

What this means for you. Anything you type into a chat, and anything a tool reports back that the assistant needs in order to answer, leaves your machine. Do not paste content into a chat that you are not permitted to disclose to a third-party AI provider — for example material under a client NDA, export-controlled data, or classified project information. Keeping a drawing local does not keep its contents local if you describe them in a message.

4. Accounts

You must be at least 18 years old and able to enter a binding contract.
You must give an accurate email address and keep your account details current.
You are responsible for everything done through your account and for keeping your password and session confidential. Tell us promptly if you believe your account has been compromised.
We do not currently verify ownership of the email address you register. Do not register an address you do not control.
Organization accounts share a single credit pool across their members. An organization owner or administrator can add members and buy credit, and can see usage attributed to individual members. If you join an organization, your usage is visible to its administrators.
You must accept the then-current version of these Terms to register. If we publish a materially changed version, you will be asked to accept it before continuing to use the Service.

Accepting during installation, and accepting as an account holder

You may be asked to accept these Terms twice, and the two are not the same act:

At installation. The Windows installer presents these Terms and requires agreement before it installs anything. That agreement is given by the person running the installer, and it governs the installation and use of the software on that computer. Where that person is installing on behalf of an organization — an IT administrator doing a deployment, for example — they confirm they are authorised to accept on its behalf, and the organization is bound.
At registration. Creating an EnginAIer account is a separate agreement covering the account, the cloud service and payment. It is accepted by the account holder in their own name and is recorded against the account with the version accepted and the time of acceptance.

We do not assume the installer and the account holder are the same person, and acceptance by one is not treated as acceptance by the other. If you use an account on a machine someone else set up, you are bound by the Terms through your own acceptance at registration, not through theirs. Only the acceptance recorded against your account governs your use of the cloud service.

5. Acceptable use

You agree not to:

Use the Service unlawfully, or to infringe anyone's intellectual property or privacy rights.
Submit content you do not have the right to submit, including third-party confidential information you are contractually barred from disclosing to a subprocessor.
Attempt to extract, reuse or resell the underlying AI model access — including reselling capacity, proxying the Service for others, or using it as a general-purpose API for work unrelated to your CAD and BIM activity.
Circumvent metering, credit limits or authentication, or tamper with the connector or client to misreport usage.
Reverse engineer, decompile or attempt to derive the source of any part of the Service, except where that right cannot lawfully be excluded.
Probe, scan, overload or disrupt the Service or its infrastructure, or use it to distribute malware.
Use the Service to generate content that is unlawful, defamatory, or that deliberately misrepresents engineering analysis as having been performed or certified by a qualified professional when it has not.
Share one account between multiple people, or share credentials outside your organization's members.

We may investigate suspected breaches and may suspend access while we do so. Serious or repeated breaches may lead to termination under section 12.

6. AI output is assistance, not engineering advice

The Service does not practise engineering. It does not perform design review, and it does not certify anything. Nothing it produces is a professional opinion, an engineering judgement, a code compliance determination, or a substitute for review by a qualified, licensed professional.

EnginAIer is built on large language models. These systems produce plausible output, which is not the same as correct output. They can and do produce results that are wrong in ways that look entirely reasonable — including geometry that is subtly misplaced, dimensions and quantities that are miscalculated, references to design standards that are outdated, inapplicable to your jurisdiction, or simply invented, and confident explanations of all of the above.

Because the Service operates on civil, structural and infrastructure design work, the consequences of relying on unverified output can include structural failure, property damage, injury and death. You therefore agree that:

You are the responsible engineer. You, and not EnginAIer, are responsible for the design. Using the Service does not transfer any part of that responsibility to us, and we accept none of it.
You must independently verify every output before relying on it — against the governing design codes, standards, specifications and regulations that apply to your project and jurisdiction, against your client's requirements, and against your own professional judgement.
Nothing produced by the Service may be issued, sealed, stamped, signed or submitted as construction, permit, tender or record documentation without review and approval by a competent person who is qualified and, where required, licensed to take responsibility for it.
The Service is not a checking tool. It does not validate your design, and the absence of a warning from it is not evidence that anything is correct. Silence is not approval.
Modifications are irreversible in your own files. The connector edits your drawings and models directly on your machine. You are responsible for backups, version control and reviewing changes before saving or issuing them.
Your professional obligations are unaffected. Any duty you owe under your licence, professional body, contract, insurance policy or applicable law continues to apply in full, and you must not use the Service in a way that conflicts with it.

Output may also be inaccurate for mundane reasons: an interrupted tool call, a stale drawing state, a misread of your intent, or a limit on how many steps the assistant may take in one turn. Treat all output as a draft prepared by an unqualified assistant that must be checked.

7. Your content and CAD files

You keep all rights in your drawings, models, documents, prompts, and anything the Service helps you produce ("Your Content"). We claim no ownership of it.

You grant us a limited licence to process Your Content only so far as is necessary to operate the Service for you — in practice, transmitting conversation content to Anthropic to obtain a response, and storing your account and metering records. We do not use Your Content to train our own models. Anthropic's handling of the content we send is governed by our agreement with them and by their published policies.

AI output is generated from your input and is not unique to you: the Service may generate similar output for other users. We make no claim of ownership over output, and we do not warrant that output is original or that using it does not infringe a third party's rights.

8. Third-party software and integrations

The Service works alongside CAD and BIM software licensed to you by others. You are responsible for holding valid licences and for complying with their terms, including any restriction on automation or third-party plugins.

If you connect an Autodesk account for Autodesk Construction Cloud access, you authorise us to store the access and refresh tokens Autodesk issues and to use them to act on your behalf within the scope you approved. You can disconnect at any time from your account page, which deletes those tokens from your user record. Your use of Autodesk services remains governed by your agreement with Autodesk.

We are not responsible for third-party services, and their availability is outside our control. Changes they make may break parts of the Service without notice.

9. Plans, credit and payment

Payments are processed by Stripe. We do not receive or store your card details. All amounts are in US dollars (USD) and are exclusive of any VAT or other tax, which is added where applicable.

Plans

A plan is a monthly subscription that carries a monthly allowance of AI credit equal to its price. Plans are available at $10, $25, $50, $100 and $250 per month, in an individual scope (a personal pool) or an organization scope (a pool shared by unlimited members). Paying yearly costs ten months' price for twelve months.

A new account starts with no plan and no credit, and cannot use AI features until a plan or credit is added.

How usage is charged

Credit is consumed per conversation turn, based on the number of input and output tokens the AI provider reports for that turn. We charge the provider's rate for the model used plus a 20% platform fee. Rates differ substantially between models; the model you select directly affects what you spend.

Item	Detail
Unit of charge	Tokens reported by the AI provider for each completed turn
Platform fee	20% over the provider's API cost
Monthly allowance	Equal to your plan price, refreshed each billing month
Rollover	Unused monthly allowance does not accumulate — the balance is restored to the allowance, not added to it
Top-ups	One-time purchases from $5 to $500, added to your balance
Empty balance	AI requests are refused until you top up or the allowance refreshes

Purchased top-up credit above your monthly allowance is carried forward and is not removed when the allowance refreshes. Metering is performed on our side from the provider's reported usage, not from anything the client reports, and our records are the record of what you owe.

For organization plans, all members draw on the same pool, and only an owner or administrator can buy credit. When the pool is empty, every member is blocked until it is topped up.

Subscription renewal

Subscriptions renew automatically at the end of each billing period until cancelled. You can cancel at any time from your account page; cancellation takes effect at the end of the period you have paid for, and you keep access until then. We may change prices with at least 30 days' notice before the change applies to your next renewal.

10. Refunds and expiry

Consumed credit is not refundable. Once a conversation turn has been processed, the AI provider has charged us for it, and that cost cannot be recovered.
Unused top-up credit may be refunded at our discretion within 14 days of purchase, less any credit already consumed. Contact us to request this.
Subscription fees are charged for the period ahead and are not refundable on a pro-rata basis when you cancel mid-period, except where a refund is required by law.
Statutory rights. If you are a consumer in the EU, EEA or UK, you have a 14-day right of withdrawal on digital purchases. That right is lost once you begin consuming credit, because you ask us to start supplying the digital service immediately. Nothing here limits any non-waivable statutory right.
Expiry. Credit on your balance does not expire while your account is open. Unused monthly allowance is not credit you have bought — it does not roll over from month to month. If your account is closed, any remaining balance is forfeited unless a refund is required by law.
Failed payments. If a payment fails, we may suspend access to paid features until it is resolved.
Billing errors. If you believe you have been charged incorrectly, contact us within 60 days of the charge and we will investigate. We may issue credit to correct a metering error.

11. Changes to the service and these Terms

The Service is under active development. We may add, change or remove features, agents, supported CAD products and AI models. We may retire an AI model when the provider does.

We may update these Terms. Each version carries a version number and effective date. For material changes we will notify you and ask you to accept the new version before you continue using the Service; your acceptance, with its version and timestamp, is recorded against your account. Minor corrections that do not affect your rights may be made without re-acceptance. If you do not accept a new version, you may stop using the Service and close your account; see section 10 on refunds.

12. Suspension and termination

By you. You may stop using the Service and close your account at any time by contacting us. Closing your account cancels any active subscription at the end of the paid period.

By us. We may suspend or terminate your access if you materially breach these Terms (in particular sections 5 and 6), if your payment fails and is not resolved, if we are required to by law, or if your use poses a security or legal risk to us or other users. Where it is reasonable and lawful to do so, we will give notice and an opportunity to fix the problem first. For serious breaches — unlawful use, security attacks, or attempts to circumvent metering — we may act immediately.

On termination. Your access to the cloud service ends. Data held on your own machine, including your local chat history, uploaded files and all your drawings and models, is unaffected and remains yours. We handle server-side data as described in the Privacy Policy. Sections 6, 7, 13, 14, 15 and 16 survive termination.

13. Disclaimer of warranties

To the fullest extent permitted by law, the Service is provided "as is" and "as available", without warranty of any kind, whether express, implied or statutory. We specifically disclaim any implied warranty of merchantability, fitness for a particular purpose, non-infringement, and any warranty arising from course of dealing or trade usage.

We do not warrant that the Service will be uninterrupted, secure or error-free, that defects will be corrected, or that any output will be accurate, complete, current, code-compliant or fit for any engineering purpose. The Service depends on third-party AI providers and third-party CAD software, and we do not warrant their performance or availability.

Nothing in these Terms excludes liability that cannot lawfully be excluded — including liability for death or personal injury caused by our negligence, and for fraud or fraudulent misrepresentation.

14. Limitation of liability

To the fullest extent permitted by law:

We are not liable for any indirect, incidental, special, consequential, exemplary or punitive damages; nor for loss of profit, revenue, business, goodwill, anticipated savings, contracts or opportunity; nor for loss or corruption of data, drawings or models — whether or not we were advised such loss was possible.
We are not liable for any loss arising from your reliance on output that you did not independently verify as required by section 6, including design errors, rework, construction cost, delay, regulatory penalty, or claims made against you by your clients or third parties.
Our total aggregate liability arising out of or relating to the Service, on any basis whether in contract, tort (including negligence) or otherwise, is limited to the greater of (a) the total amount you paid us in the twelve months immediately before the event giving rise to the claim, or (b) US$100.

This allocation of risk is a fundamental basis of the bargain between us and is reflected in the price of the Service. If your work requires a different allocation of risk, do not use the Service.

15. Indemnity

You will indemnify and hold harmless Digital Thread AI and its officers, employees and agents from any claim, loss, liability, damage, cost or expense (including reasonable legal fees) arising from your use of the Service, your breach of these Terms, your infringement of any third party's rights, or any claim relating to a design, drawing, model or deliverable you produced with the assistance of the Service. This does not apply to the extent the claim arises from our own wilful misconduct.

16. Governing law and disputes

[PLACEHOLDER 3 — governing law and venue. Open question; must not be guessed.] These Terms are governed by the laws of [JURISDICTION], without regard to its conflict of law rules. The courts of [VENUE] have exclusive jurisdiction over any dispute arising out of or in connection with these Terms, except that either party may seek injunctive relief in any competent court. Also specify whether arbitration applies, and preserve a consumer's right to bring proceedings in their country of residence, since mandatory EU and UK consumer protections cannot be overridden by this clause. Note that the cloud service being hosted in Frankfurt does not by itself determine the governing law of this contract; it is a fact about where data is processed, addressed in the Privacy Policy.

If any provision of these Terms is held unenforceable, it is modified to the minimum extent necessary to make it enforceable, and the remaining provisions stay in force. Our failure to enforce a provision is not a waiver of it. You may not assign these Terms without our consent; we may assign them to a successor in connection with a merger, acquisition or sale of assets.

These Terms, together with the Privacy Policy, are the entire agreement between us regarding the Service and supersede any prior understanding.

17. Contact

These Terms are with Digital Thread AI. Questions about them, billing disputes, refund requests and account closure should be sent to the address below.

[PLACEHOLDER 4 — general contact email.] Insert the email address that receives questions about these Terms, billing disputes, refund requests and account closure. No address has been assumed here, because publishing one that does not receive mail is worse than publishing none.

Privacy and data protection requests go to the separate contact given in the Privacy Policy.