Terms of Use

Publisher

HeyFit is published by FASTOCHE, a French simplified joint-stock company (SAS) with a share capital of €3,000, registered with the Aix-en-Provence Trade and Companies Register under number 922 556 212 (SIRET 922 556 212 00020), with its registered office at 1004 route de Coudoux, 13122 Ventabren, France. Contact: hello@heylio.io.

HeyFit is intended for businesses selling on Shopify. It is not intended for consumers.

The service

HeyFit is a Shopify app that lets the merchant:

• create size charts (by hand, from a template, from a CSV file, or through an artificial-intelligence import that suggests a chart from an image, a public web page or a product description) and assign them to products, collections, product types or the whole store;
• show a “Find my size” button on product pages, which displays the size chart and suggests a size to the customer from the measurements they enter or, if they don’t know them, from measurements estimated from their height, weight and age (estimated advice);
• adjust that size based on the size returns sent by HeyReturn, or on the merchant’s own statements about a product.

HeyFit reads the store’s catalog in read-only mode (Shopify read_products scope): it never changes products, orders or customers.

The artificial-intelligence import relies on a third-party provider (OpenRouter, which passes the content to Anthropic’s Claude model), to which HeyFit sends, once, only the content chosen by the merchant, as described in the privacy policy. It is limited to 20 imports per store per day, and reserved for owners and administrators.

Installation and access

HeyFit is installed from the store’s Shopify admin. It then opens inside the Shopify admin, or on app.heyfit.app with a Heylio suite account.

The merchant is responsible for the people they give access to and for their role: Owner and Administrator can change HeyFit, Agent can only view it. The merchant keeps their access confidential.

Plans, price and trial

• HeyFit offers two plans. The Free plan, with no subscription: one published size chart, shown on product pages as a size table, with no size recommendation, no “Select size” and no learning from HeyReturn returns.
• The HeyFit plan, all included (unlimited size charts, size recommendations, “Select size”, learning from returns), is offered as a monthly subscription, at €19 per month, excluding taxes, for a store that Shopify bills in euros, and $19 (US dollars) per month, excluding taxes, for all other stores.
• The subscription is billed by Shopify, on the store’s Shopify bill, under Shopify’s billing terms. Prices exclude taxes: any applicable VAT or local tax is calculated and added by Shopify to its bill. FASTOCHE never receives or stores any payment method.
• A store’s first subscription starts with a 14-day free trial. The trial applies once per store, and its end date is set when it starts: it is neither paused nor extended by switching back to the Free plan or uninstalling. A new subscription before that date only gets the days left until it; a subscription after that date includes no trial.
• The subscription is activated from HeyFit, then approved on Shopify’s screen. A price change would only apply once the merchant has approved it in Shopify.
• Without an active subscription or ongoing trial, the store moves to the Free plan: only its first size chart stays published, as a size table. Its other size charts are never deleted: they are kept, not shown, and come back as soon as the subscription starts.
• Stores that were using HeyFit before October 9, 2026 keep full access, without a subscription, until November 9, 2026; after that date, the rules above apply.

Term and cancellation

The subscription has no minimum term. The merchant can end it at any time, without uninstalling, with “Switch to the Free plan” in HeyFit’s Settings: the subscription is cancelled at once in Shopify, with no refund or credit for the current period already paid, and the store moves to the Free plan as soon as it is cancelled. Nothing is deleted; a running trial ends and does not reopen beyond its original end date. Uninstalling HeyFit from the Shopify admin also stops the subscription, under Shopify’s billing rules.

On uninstall, HeyFit’s access to the store is cut immediately; the store’s data is deleted 48 hours later, at Shopify’s request, as described in the privacy policy.

FASTOCHE may suspend access for a store that uses HeyFit in breach of these terms or of the law, or that threatens the security of the service, after informing the merchant except in an emergency.

Merchant commitments

• Enter accurate size charts and keep them up to date: they are the basis of the suggested size. A chart suggested by the artificial-intelligence import is checked by the merchant before it is created.
• Only import through artificial intelligence content they are entitled to use, and no personal data about their customers.
• Use HeyFit in compliance with the law and with Shopify’s terms.
• Remain solely responsible, towards their customers, for their product information, sales and return policy.

A recommended size, for guidance only

The size suggested by HeyFit is advice, computed from the merchant’s size charts, the measurements entered by the customer and, where applicable, the returns received. It is for guidance only: it guarantees neither that the item will fit the customer, nor fewer returns.

Estimated advice, computed from the customer’s height, weight and age using public anthropometric reference data, is less reliable than advice based on their measurements, and is presented as such to the customer.

A chart suggested by artificial intelligence is a suggestion that may contain errors: it is only created after the merchant has reviewed and approved it, and the merchant remains responsible for it.

The customer remains free to choose their size. The result depends on the accuracy of the charts and of the measurements entered.

Availability

FASTOCHE makes its best efforts to keep HeyFit available and working properly, but cannot guarantee an uninterrupted or error-free service. The service depends on Shopify and on the hosting providers listed in the privacy policy; it may be interrupted for maintenance.

If HeyFit does not respond, the button is not shown and the product page keeps working normally.

Liability

To the extent permitted by law, FASTOCHE is only liable for direct damage caused by its own fault in providing HeyFit, and its liability is limited to the amount paid for HeyFit by the store concerned during the twelve months preceding the event giving rise to the claim.

FASTOCHE is not liable for indirect losses (revenue, sales, returns, reputation), for the consequences of an inaccurate chart or measurement, or for interruptions caused by Shopify or a third party.

Intellectual property

HeyFit, its code, interface and trademarks belong to FASTOCHE. The subscription grants the merchant a right to use HeyFit for their store, for the duration of the subscription, with no other transfer of rights.

The merchant remains the owner of their size charts and of the content they enter. They authorize FASTOCHE to use it to provide the service to their store, including sending the content they choose to import to the artificial-intelligence provider, and for nothing else.

Personal data

The data HeyFit processes, its retention, its deletion and your rights are described in the privacy policy: app.heyfit.app/privacy. HeyFit stores no personal data about the store’s customers.

Changes to these terms

FASTOCHE may update these terms. The date at the top of this page changes with each version; a significant change is announced to merchants in advance, in HeyFit or by email. Continuing to use HeyFit after it takes effect means accepting it.

Governing law and disputes

These terms are governed by French law. In the event of a dispute, the merchant and FASTOCHE first seek an amicable solution, by writing to hello@heylio.io. Failing that, the dispute is brought before the competent courts for FASTOCHE’s registered office (Aix-en-Provence, France).

These terms are published in French and English; in the event of any discrepancy, the French version prevails.

Contact

For any question about these terms: hello@heylio.io, or FASTOCHE, 1004 route de Coudoux, 13122 Ventabren, France.