Terms of Service

Last updated: September 29, 2026

Gustave's legal documents are published in English and in French, with the same content. For consumers residing in France, the French version prevails in case of discrepancy; in all cases, any ambiguity is interpreted in the way most favourable to you.

These Terms of Service (the "Terms") govern your use of Gustave, meaning the Gustave browser extension (the "Extension") and the meetgustave.app website (the "Website"), together the "Service". The Service is published by 3h53 SAS ("we", "us"), whose details are given in the Legal Notice. Purchases in euros are also governed by the Terms of Sale, and your personal data by the Privacy Policy.

1. The Service

Gustave is a pixel-art companion who lives on your browser's New Tab page, which the Extension replaces. The Extension estimates the number of tokens in the messages you exchange on compatible AI chat services, currently chatgpt.com, claude.ai and gemini.google.com (the "AI Services"), and turns them into gems (◆). Gems let you obtain cosmetic items for Gustave and his scenery, shown on your new tab and on your public page.

The Service is free; some items can optionally be bought with euros. Gustave is an independent project, neither affiliated with nor endorsed by OpenAI, Anthropic or Google: their services are named only to state compatibility, and their trademarks belong to their owners. Your use of the AI Services remains subject to their own terms.

2. Acceptance and eligibility

By installing the Extension, creating an account or using the Website, you accept these Terms. If you do not accept them, do not use the Service.

You must be at least 15 years old to create an account, or any higher age set by your country of residence for consenting alone to the processing of your personal data. If you are a minor, any purchase in euros requires the prior approval of the holder(s) of parental authority.

3. Your account

An account is needed to keep your gems, buy items, appear on the leaderboards and have a public page. Without an account, the Extension works locally and nothing is stored on our servers.

Sign-in: by email, with a one-time code or a sign-in link, without a password, or, if you prefer, with your Google account. You are responsible for the security of your mailbox (and of your Google account if you use it); report any unauthorised use to hello@meetgustave.app.
Personal account: one account per person, which may not be sold, rented, transferred or shared.
Username: unique and public, it must comply with section 10 and must not be confusable with a person, a brand or Gustave. We may refuse or reset it.
Deletion: at any time, from your account page ("My Gustave") or by writing to hello@meetgustave.app from your account's email address (deletion then takes place within 30 days). Deletion is final: gems, level, items (including those bought with euros) and content are lost, except for the data we must keep (see the Privacy Policy).

4. Token estimates

On the AI Services, the Extension reads, on your device, the network responses and the displayed text of your conversations to estimate the tokens of each new message, sent or received. Only numbers and technical data are sent to us, never the text, except in Verified mode. You can turn counting off for each site from the Extension's window.

Figures marked "~" or "estimated" are approximations computed by Gustave, not official figures from the AI Services' providers, whose own measurements (usage, quotas, billing) may differ. Each message is counted only once, without the context that the AI Service re-reads at each turn. The AI Services may change their pages without notice and disrupt counting: we adapt the Extension as best we can, without guarantee, and uncounted tokens cannot be claimed.

Verified mode (optional). For claude.ai and gemini.google.com (not yet for chatgpt.com), your own API key lets you obtain the exact number of tokens from the provider's official token-counting endpoint; this number feeds the "Verified" leaderboard. Your key stays stored in your browser; the text and the key pass through our server only for the count and are not kept. The terms and any fees of your API account remain your responsibility.

5. Gems (◆) and levels

Tokens credited to your account raise your level and earn you gems at the rate shown in the Service, currently one gem per 25,000 tokens. Gems can also be obtained by selling items at the Market, through promotional codes or events, or through an adjustment by our team.

Gems are a virtual in-game unit that can only be used within Gustave. They:

have no monetary value and are not money, electronic money, a crypto-asset or a financial instrument;
can never be bought with money;
can never be exchanged for money, goods or services outside Gustave, and are not refundable;
cannot be transferred to another account, except to pay for an item bought from another player at the Market;
give you only a personal right of use within the Service, not ownership.

We may correct your tokens, gems or level in case of error, bug, abnormal counting or breach of these Terms. We may also change the conversion rate, the level curve and prices in gems to keep the game balanced; such changes apply to the future and do not reduce gems already credited, except for corrections. Gems are lost if your account is deleted or closed.

6. Items

Items (Gustave's outfits and colours, backgrounds, sky objects, companions, decor, etc.) are purely cosmetic: they give no advantage for counting, levels or leaderboards.

How to get them: with gems in the shop, as starter items or level rewards, through promotional codes (under the conditions announced when they are issued) or events, or, for some of them (Premium Items), with euros (see the Terms of Sale). You can try everything on for free, but only the items you own can be saved in your outfit. Unless stated otherwise, each item can be bought only once per account in the shop.
Limited availability: some items are offered only during a yearly event (Halloween, Christmas, New Year, Valentine's Day, Easter, Summer, etc.) or within a collection; others are numbered limited editions (for example "No. 12/1000"). Once the event is over or the edition is sold out, they only circulate through the Market.
Account-bound items: starter items, level rewards and items marked as such can be neither sold nor traded.
Right of use: an item gives you a personal, non-exclusive right to use it within the Service as long as your account exists and the Service is operated, with no rights in the artwork itself.
Changes: we may improve an item's appearance without changing its nature, withdraw items from the shop or change their price for the future. Your items stay in your inventory, except for corrections (item granted by mistake) or sanctions.

7. The Market

The Market, the marketplace between players, lets you sell your items to other players and buy theirs, with gems only: no money ever changes hands on it.

Conditions: only tradable items can be listed, subject to the conditions shown in the Service (minimum level, maximum number of listings, safety delay before some items can be resold, in particular those bought with euros). A listed item is reserved; you can withdraw the listing as long as it has not sold.
Fee: the seller sets the price in gems. A 5% fee, in gems, is deducted from each sale and destroyed: it is paid to no one.
Final sales: the item goes to the buyer and the gems to the seller immediately, with no cancellation or refund, except in case of obvious error, bug or fraud.
Transparency: listings and sales (item, edition number, price, date) are public, together with the usernames of players whose profile is public, and are used to compute item price indicators. By default, listings are sorted from newest to oldest; no payment can improve their visibility.

The following are forbidden: selling, buying or exchanging items, gems or accounts for real money, crypto-assets, goods or services, on Gustave or elsewhere (third-party sites, social networks, messaging apps, etc.); arrangements between accounts to transfer gems or items or to manipulate prices; exploiting a bug. Such breaches may lead to the cancellation of transactions, the removal of the items and gems concerned and the suspension or closure of the accounts involved. We may suspend or close the Market, in particular to fight fraud.

8. Leaderboards

The Estimated leaderboard ranks players whose profile is public by the total tokens credited (estimated and verified), marked with "~". The Verified leaderboard only takes into account tokens counted exactly in Verified mode.

Rank depends only on the number of tokens credited: no payment or item purchase affects it. Leaderboards show the username, display name, level, number of tokens and outfit. Private profiles are not listed, and accounts under anti-cheat review are temporarily removed. Leaderboards do not entitle anyone to a prize, unless specific rules are published for an event.

9. Fair play and anti-cheat

You may not modify or circumvent the Extension, its protections or our servers (except where the law allows it), send requests or counts that are forged, replayed or not produced by genuine use of the AI Services, generate conversations with bots or scripts to inflate your counters, use several accounts to accumulate or transfer gems or items, or exploit a bug instead of reporting it to hello@meetgustave.app.

Caps apply automatically to every account (per message, per minute and over a rolling 24-hour period): tokens above them are not credited. The source of each count is recorded and checked. An account with abnormal activity may be automatically removed from the leaderboards while a member of our team reviews it; no cancellation of gains and no suspension for cheating is decided without this human review. We may then cancel unfairly obtained tokens and gems, remove the items acquired with them, or suspend or close the account (section 15), through a proportionate decision that states its reasons and can be challenged (section 11).

10. Your content

You can personalise your world with your username, a display name, a message on the sign, a website shown in a "web panel" decor, a photo in a frame, the text of a banner towed by a plane and up to six links (https or mailto) with generic icons. This content is visible to everyone on your public page when your profile is public; the first name used to greet you on your new tab stays private.

You are solely responsible for your content and warrant that you hold the necessary rights, including the consent of any recognisable person in a photo. Content is forbidden if it:

is illegal, hateful, discriminatory or violent, or glorifies terrorism or crimes;
amounts to harassment, threats, insults or defamation;
is sexual or pornographic, or sexualises minors in any way;
leads to malware, phishing or scams, or is spam;
infringes the rights of others (intellectual property, trademarks, image rights, privacy, personal data);
impersonates anyone or falsely suggests a link with Gustave or with an AI Service provider;
points to the sale of items, gems or accounts for money.

The web panel only displays https websites, and some websites refuse to be displayed in a frame. Displayed websites and links lead to third-party content, for which those third parties remain responsible.

You keep your rights. You grant us, worldwide and for as long as the content is published (plus the technical time needed to erase it), a free, non-exclusive licence to host, reproduce, technically adapt (resizing, pixel effect) and display your content within the Service, including in your page's preview image. We do not review content before publication, but we act on reports and may act on our own initiative.

11. Reporting and moderation

Reporting. Each public page has a "Report" button, available to signed-in users. Anyone, even without an account, can also report content they consider illegal to hello@meetgustave.app, stating: a sufficiently substantiated explanation of why it is illegal; its exact location (page address and content concerned); their name and email address, except for child sexual abuse material; and a statement confirming their good faith and the accuracy of the information. We acknowledge receipt of reports and tell their authors what action was taken.

Handling. We handle reports diligently and objectively. When several different users report the custom content of the same page (sign, web panel, photo, banner, links), that content is automatically hidden pending review. This temporary hiding and anti-cheat detection are our only automated measures: every final decision is taken by a member of our team. Depending on the severity, we may remove or hide content, reset a username, restrict a feature, or suspend or close an account. We promptly remove manifestly illegal content and inform the authorities where the law requires it, in particular in case of a threat to the life or safety of persons. You can also report illegal content to the French authorities through the PHAROS platform: www.internet-signalement.gouv.fr.

Statement of reasons. When we restrict your content or your account, we tell you by email the measure taken, its scope and duration, the facts it is based on (and whether they come from a report), whether automated means were used, the legal rule or section of these Terms concerned, and your means of redress.

Complaints. For six months after a decision, both the user concerned and the author of the report can challenge it free of charge by replying to the notification email or writing to hello@meetgustave.app. The complaint is reviewed by a person; if it is well founded, the decision is reversed or modified without undue delay. You may also use consumer mediation (section 18) or, where applicable, a certified out-of-court dispute settlement body under the EU Digital Services Act (DSA), lodge a complaint with Arcom, the French Digital Services Coordinator, or go to court.

Misuse. After a warning, we suspend for a reasonable period the accounts that frequently publish manifestly illegal content, and the processing of reports from those who frequently submit manifestly unfounded ones. We take into account the number, proportion and severity of the misuse and the intent behind it. As a guide, the suspension lasts 7 days the first time and 30 days for a repeat offence; the most serious cases may lead to the closure of the account.

12. Public page

Your public page (meetgustave.app/u/your-username) shows your scene, username, display name, level, estimated and verified tokens, rank, collection with edition numbers, and your content. It can be shared and indexed by search engines.

Your profile is private by default. You can make it public, then private again, at any time from the extension or your account page. While it is private, your page is not accessible, you do not appear on the leaderboards and your username is not shown at the Market.

13. Intellectual property

Gustave (name, character, logo, pixel art, animations, items, texts), the software of the Extension and the Website and their databases are protected; they belong to us or are used with their owners' permission. We grant you a personal, non-exclusive and non-transferable right to use the Service for private, non-commercial purposes.

You may share screenshots of your scene and the downloadable images offered by the Service, and use your Gustave as a profile picture, including on social networks, for personal and non-commercial purposes, without altering them in a way that suggests our endorsement. Any other use, in particular commercial use (merchandise, resale, NFTs, training of artificial intelligence models), requires our prior written consent. Extracting a substantial part of our databases, including by automated scraping, and decompiling the Extension are forbidden, except where the law allows it (Article L122-6-1 of the French Intellectual Property Code).

14. Availability and changes to the Service

The Service is provided free of charge, as is. We use our best efforts to keep it working properly, without guaranteeing continuous availability or the absence of errors: maintenance, updates or incidents may interrupt it. It also depends on third parties (AI Services, browsers, extension stores, hosting providers), and older versions of the Extension may stop working.

We may change the Service (features, compatible sites, items, game economy) for a valid reason: technical developments, security, game balance, fraud prevention, legal compliance or changes to the AI Services. If a change significantly reduces your use of the Service, we will notify you in advance where possible. If we shut down the Service, we will inform you by email and on the Website at least 60 days in advance, except in case of force majeure or legal obligation; what happens to items bought with euros is set out in the Terms of Sale.

15. Suspension and termination

You can stop using the Service at any time, delete your account and uninstall the Extension.

If you breach these Terms, we may suspend or close your account, after a warning where possible. In case of a serious breach (cheating, selling for real money, manifestly illegal content, fraud, attack on the security of the Service, abusive payment dispute), the measure may be immediate. Unless you are in breach, we will not close your account without reasonable notice. Every decision states its reasons and can be challenged (section 11).

Closing an account means losing its gems, level, items and content. If the account is closed for a serious breach attributable to you, items bought with euros are not refunded, unless the law provides otherwise.

16. Liability

We are liable, under general French law, for direct and foreseeable damage caused by a breach of our obligations. We are not liable where the damage results from your own conduct (in particular use contrary to these Terms), from the unforeseeable and insurmountable act of a third party, or from force majeure (Article 1218 of the French Civil Code). We are not responsible for third-party content and services (AI Services, displayed websites, links), nor for differences between our estimates and the providers' official figures.

Nothing in these Terms limits our liability for personal injury, gross negligence or wilful misconduct, or the rights you have under mandatory consumer protection rules.

17. Changes to these Terms

We may change these Terms, in particular to reflect changes to the Service or to the law. For any substantial change, we will notify you by email or in the Service at least 30 days before it takes effect; if you do not accept it, you can delete your account before that date. Minor corrections and changes required by law may apply as soon as they are published. The current version is always available on this page.

18. Complaints, mediation and governing law

For any complaint, please write to us first at hello@meetgustave.app.

The free Service is not a paid consumer contract, so consumer mediation does not apply to it; for paid purchases, consumer mediation is described in the Terms of Sale.

These Terms are governed by French law, without depriving you of the mandatory protections of the law of your country of residence if you live in another EU Member State. Failing an amicable settlement, you may bring the dispute before any court having territorial jurisdiction under the French Code of Civil Procedure, or before the court of the place where you lived when the contract was concluded or when the harmful event occurred (Article R631-3 of the French Consumer Code); if you live in another EU Member State, you may also bring proceedings before the courts of your country.

These Terms are published in English and in French, with the same content. For consumers residing in France, the French version prevails in case of discrepancy; in all cases, any ambiguity is interpreted in the way most favourable to the consumer (Article L211-1 of the French Consumer Code).

19. Contact

hello@meetgustave.app — 16 A rue du Pré d'Avril, 74940 Annecy, France. The publisher's full details are given in the Legal Notice.