Legal
How Haunch may be used, what we do with your data, and the limits of what a calculation tool can be relied upon to do. Written to be read — not buried.
Haunch runs verified Eurocode design checks and produces fully referenced calculation output across the web app, REST API, CLI and MCP server. It is a calculation aid for qualified structural engineers — not a substitute for engineering judgement.
Outputs are provided for reference only. They do not constitute engineering advice, certification, or approval of any kind. Every result must be independently verified by a competent engineer before use in any design, submission, or construction context.
You are solely responsible for ensuring that any work informed by Haunch outputs complies with the applicable codes, standards, National Annexes, regulations, and professional obligations in your jurisdiction. Haunch covers the UK and Irish National Annexes; if your inputs fall outside a calculation's validated scope, the tool says so explicitly rather than returning a plausible-looking answer — but the duty to check remains yours.
Using Haunch does not transfer professional responsibility away from you. Haunch Ltd accepts no liability for loss, damage, injury, or any other consequence arising from reliance on outputs produced by the service, whether or not those outputs contain errors.
By using Haunch you agree to these terms. “Haunch” refers to Haunch Ltd and its services at haunch.dev, including the web app, REST API, command-line interface, and MCP server.
Access to the Solo plan is provided on a monthly subscription at £19/month, billed through Stripe. You may cancel at any time from the billing portal; cancellation takes effect at the end of your current billing period and you keep access until then. Refunds are reviewed case-by-case within 14 days of a charge — contact [email protected].
You may use Haunch for lawful professional purposes only. You may not resell, sublicense, or share access in a way that circumvents per-user subscription; scrape or bulk-extract the calculation library; or use the service or its outputs to train machine-learning models without written permission. API, CLI and MCP access is subject to fair-use rate limits — automated abuse that degrades the service for others may be throttled or suspended.
We aim to keep Haunch available and accurate, but the service is provided “as is” without warranty of uninterrupted availability. Calculations are validated against published Eurocode worked examples before release; even so, the verification duty in Section 01 always applies.
To the maximum extent permitted by law, Haunch Ltd's total liability for any claim arising out of your use of the service is limited to the amount you paid in the 12 months preceding the claim. We are not liable for indirect, incidental, or consequential losses. Nothing in these terms limits liability that cannot be excluded under law.
We may update these terms with reasonable notice. Continued use after notice constitutes acceptance.
We collect and process personal data only to run and improve the service. This policy applies to haunch.dev and everything connected to it, and is governed by UK GDPR. We do not sell your data or use it for advertising.
Identity — your name and email address, via Clerk, our authentication provider. Billing — payment method and billing history, via Stripe, our payment processor (we never store full card details). Calculation data — the inputs you submit and the outputs Haunch generates across the web app, API, CLI and MCP server. Usage — product analytics such as page views and feature interactions.
To authenticate you, take payment, run the calculation service, send transactional email (receipts and account notices), and understand which features to improve. Calculation inputs and outputs are processed to deliver and store your own work — they are not used to train machine-learning models.
We share data only with the sub-processors needed to run the service. Each operates under its own data-processing agreement compliant with UK GDPR:
Account and calculation data is retained for the life of your account plus 90 days after deletion, after which it is purged from active systems. Financial records are kept for 7 years as required by UK law.
Under UK GDPR you have the right to access, correct, export, or delete your data, and to object to processing. To exercise any of these, email [email protected] — we'll respond within one month. You may also lodge a complaint with the ICO at ico.org.uk.