PUBLIC OFFER AGREEMENT for the provision of services

Note: This is an informational translation. The legally binding version of this document is in Russian.

1. General Provisions

This Public Offer contains the terms and conditions for concluding an Agreement for the provision of services (hereinafter referred to as the "Service Agreement" and/or the "Agreement"). This offer is a proposal addressed to one or more specific persons, which is sufficiently definite and expresses the intention of the person making the proposal to consider themselves as having concluded the Agreement with the addressee who accepts the proposal.

The performance of the actions specified in this Offer constitutes confirmation of the consent of both Parties to conclude the Service Agreement on the terms, in the manner and to the extent set forth in this Offer.

The text of this Public Offer below is an official public proposal by the Service Provider, addressed to interested parties, to conclude a Service Agreement in accordance with the provisions of paragraph 2 of Article 437 of the Civil Code of the Russian Federation.

The Service Agreement shall be deemed concluded and shall take effect from the moment the Parties perform the actions provided for in this Offer, signifying unconditional and full acceptance of all the terms of this Offer without any exceptions or limitations.

Terms and Definitions:

Agreement — the text of this Offer with Appendices, which are an integral part of this Offer, accepted by the Customer through conclusive actions provided for in this Offer.

Conclusive actions — behavior that expresses consent to a counterparty's proposal to conclude, amend, or terminate an agreement. Such actions consist of full or partial performance of the conditions proposed by the counterparty.

Service Provider's Website — a set of computer programs and other information contained in an information system, accessible via the Internet at the domain name and network address: https://debutario.app/

Parties to the Agreement (Parties) — the Service Provider and the Customer.

User (Customer) — an individual who has registered on the Website (via email or through the Yandex and VK OAuth services) and accepted the terms of this Offer.

Service — providing access to the functionality of the Debutario service: ready-made openings (sets of lines with move explanations and training) and the "Repertoire" section for building a personal opening repertoire with practice over the saved lines. Part of the functionality is provided free of charge, extended access is provided under the "Pro" plan. The composition of the free and paid functionality, as well as the limits that currently apply to free use, are determined by the Service Provider and published on the Website.

"Pro" Plan — paid access of the Customer to the extended functionality of the Website for the paid period. The plan is paid for with a one-time payment for 1, 3, 6 or 12 months and is not a subscription: there is no auto-renewal and no automatic charges; upon expiration of the paid period, access to the extended functionality is suspended.

"Pro" plan includes: • access to all lines of the ready-made openings (the set of lines open free of charge is determined by the Service Provider and stated on the Website); • removal of the limit on the number of saved moves in the "Repertoire" section (in free mode the size of the saved repertoire is limited; the limit currently in effect is stated on the Website; practice over the saved lines and cross-device synchronization are available free of charge to all registered users).

The current terms and cost of the "Pro" plan on sale are determined on the Service Provider's Website on the "Pro" plan page.

2. Subject of the Agreement

2.1. The Service Provider undertakes to provide the Customer with access to the extended functionality of the Debutario service ("Pro" plan), and the Customer undertakes to pay for the Services in the amount, manner and terms established by this Agreement.

2.2. The composition, cost and duration of the "Pro" plan are determined on the Service Provider's Website at: https://debutario.app/

2.3. The Service Provider provides the Services under this Agreement personally or with the involvement of third parties, while the Service Provider is responsible for the actions of third parties as for its own.

2.4. The Agreement is concluded by accepting this Offer through conclusive actions, expressed in: • actions related to registering an account on the Service Provider's Website; • placing and sending a request by the Customer to the Service Provider for the provision of Services; • actions related to payment for the Services by the Customer; • actions related to the provision of Services by the Service Provider. This list is not exhaustive; there may be other actions that clearly express a person's intention to accept the counterparty's offer.

2.5. Upon registration on the Website (via email or through OAuth services), the Service Provider receives and processes the following personal data of the User: email address, as well as name and profile photo (when provided by the OAuth provider). The specified data is processed for the purposes of user identification, provision of Services, and saving learning progress. Personal data processing is carried out on the basis of paragraph 5, part 1, article 6 of Federal Law No. 152-FZ dated July 27, 2006 "On Personal Data" (performance of an agreement to which the personal data subject is a party). The detailed procedure for personal data processing is determined by the Privacy Policy posted on the Website.

3. Rights and Obligations of the Parties

3.1. Rights and obligations of the Service Provider:

3.1.1. The Service Provider undertakes to provide access to the "Pro" plan functionality in accordance with the provisions of this Agreement, within the timeframes and scope specified in this Agreement and (or) in the manner indicated on the Service Provider's Website.

3.1.2. The Service Provider undertakes to provide the Customer with access to the sections of the Website necessary for receiving Services, in accordance with clause 2.1. of the Agreement.

3.1.3. The Service Provider undertakes to ensure the operability of the Website and the availability of Services (except for scheduled maintenance and force majeure circumstances).

3.1.4. The Service Provider is responsible for the storage and processing of the Customer's personal data, ensures the confidentiality of such data, and uses them exclusively for the quality provision of Services to the Customer.

3.1.5. The Service Provider reserves the right to change the terms (period) of Service provision and the conditions of this Offer unilaterally without prior notice to the Customer, by publishing such changes on the Service Provider's Website. New / amended conditions indicated on the Website apply only to newly concluded Agreements.

3.2. Rights and obligations of the Customer:

3.2.1. The Customer is obliged to provide accurate information about themselves during registration and payment.

3.2.2. The Customer undertakes not to transfer access to their account to third parties.

3.2.3. The Customer undertakes to use the Website Materials in accordance with clause 3.3 of this Offer and not to provide third parties with access to them.

3.2.4. The Customer undertakes to accept the Services provided by the Service Provider.

3.2.5. The Customer has the right to demand from the Service Provider a refund for services not rendered, services rendered poorly, services rendered in violation of deadlines, as well as if the Customer decides to refuse services for reasons not related to breach of obligations by the Service Provider, exclusively on the grounds provided by the current legislation of the Russian Federation (Article 32 of the Consumer Protection Law).

3.2.6. The Customer guarantees that all terms of the Agreement are understood; the Customer accepts the terms without reservations and in full.

3.3. Intellectual property:

3.3.1. The explanatory texts for moves and opening lines, the selection and arrangement of the lines of the ready-made openings, and the database of opening lines (moves, explanations, evaluations, board markup and statistics as systematized on the Website) (hereinafter the "Website Materials") are results of intellectual activity and objects of related rights. The exclusive rights to them, including the exclusive right of the database maker, belong to the Service Provider (Articles 1259, 1260, 1304, 1333 and 1334 of the Civil Code of the Russian Federation) and apply by operation of law to any person, including persons who have not concluded the Agreement.

3.3.2. Individual chess moves, chess games and statistics of played games are not, as such, objects of the Service Provider's exclusive rights. The explanatory texts, the database as a whole and the selection of lines — the set of lines and variations, including the opponent's replies, for each opening and the order in which they are presented — are protected.

3.3.3. The Customer may use the Website Materials for personal non-commercial purposes — to study, train and play their own games, including making personal notes without providing third parties with access to them. No exclusive rights to the Website Materials are transferred to the Customer.

3.3.4. Except as provided by clauses 3.3.3 and 3.3.5 and by law, without the written permission of the Service Provider it is prohibited: • to extract the Website Materials or a substantial part of them, i.e. to transfer them to another medium by any means, including automated means (scraping, scripts, calls to the Website's programming interface bypassing the user interface), as well as to repeatedly extract insubstantial parts of the Website Materials where this conflicts with the normal use of the database and unreasonably prejudices the legitimate interests of the Service Provider (Article 1334 and paragraph 3 of Article 1335.1 of the Civil Code of the Russian Federation); • to reproduce the selection of lines of the Website or a substantial part of it on other resources, including with different explanations, in a changed order or in a different format; • to reproduce, distribute, translate or otherwise adapt the explanatory texts, including with the help of software and artificial intelligence systems, and to publish the result; • to include the Website Materials in other websites, applications, courses, books, databases and datasets for training artificial intelligence systems.

3.3.5. The following is not an infringement: • using the studied moves and variations in one's own games, study and analysis; • quoting individual lines and fragments of explanations for scientific, polemical, critical, informational and educational purposes to the extent justified by the purpose of quotation, with the author and the source — the Website — indicated (subparagraph 1 of paragraph 1 of Article 1274 of the Civil Code of the Russian Federation).

3.3.6. In the event of infringement of the exclusive rights to the Website Materials, the Service Provider may demand that the infringement be stopped and the unlawfully published Website Materials be removed, and, at its option, demand compensation for losses or payment of compensation under Articles 1252.1, 1301 and 1311 of the Civil Code of the Russian Federation (in particular, a fixed amount from RUB 10,000 to RUB 10,000,000). The Service Provider may also demand that access to resources hosting the Website Materials unlawfully be restricted under Article 15.2 of Federal Law No. 149-FZ of July 27, 2006.

3.3.7. The Services are provided through the Website's user interface. The Service Provider may restrict automated access to the Website and its programming interface by technical means.

4. Cost, Payment and Refund Procedures

4.1. The cost of the "Pro" plan is indicated on the Service Provider's Website at: https://debutario.app/ Payment is made electronically through the Robokassa payment system.

4.2. The "Pro" plan is paid for the period chosen by the Customer. Upon expiration of the paid period, access to the extended functionality is suspended until re-payment.

4.3. After successful payment, the Customer receives an electronic receipt at the specified email address in accordance with the requirements of Federal Law No. 422-FZ dated November 27, 2018.

4.4. Upon the Customer's refusal of services during the paid period, a refund is made for the actually unused part of the paid period. The refund amount is calculated proportionally to the number of remaining calendar days of the paid period, minus the actual expenses incurred by the Service Provider, including the payment processor (Robokassa) commission for payment processing and refund. To process a refund, the Customer sends a request to: support@debutario.app.

5. Confidentiality and Security

5.1. In the implementation of this Agreement, the Parties ensure the confidentiality and security of personal data in accordance with the current edition of Federal Law No. 152-FZ dated July 27, 2006 "On Personal Data" and Federal Law No. 149-FZ dated July 27, 2006 "On Information, Information Technologies and Information Protection".

5.2. The Parties undertake to maintain the confidentiality of information received during the execution of this Agreement and to take all possible measures to protect the received information from disclosure.

5.3. Confidential information means any information transmitted by the Service Provider and the Customer in the process of implementing the Agreement and subject to protection, with the exception of information that is publicly available in accordance with the current legislation of the Russian Federation.

5.4. Personal data processing is carried out in accordance with the Privacy Policy posted on the Website.

6. Force Majeure

6.1. The Parties are released from liability for non-performance or improper performance of obligations under the Agreement if proper performance was impossible due to force majeure, i.e. extraordinary and unavoidable circumstances under the given conditions, including: government prohibitions, epidemics, blockades, embargoes, earthquakes, floods, fires, or other natural disasters.

6.2. In the event of such circumstances, the affected Party is obliged to notify the other Party within 30 (thirty) business days.

6.3. A document issued by an authorized government body shall be sufficient confirmation of the existence and duration of force majeure.

6.4. If force majeure circumstances continue for more than 60 (sixty) business days, each Party has the right to unilaterally withdraw from this Agreement.

7. Liability of the Parties

7.1. In case of non-performance and/or improper performance of obligations under the Agreement, the Parties shall be liable in accordance with the terms of this Offer and the legislation of the Russian Federation.

7.2. The Service Provider shall not be liable for non-performance and/or improper performance of obligations under the Agreement if such non-performance and/or improper performance was caused by the Customer's fault.

7.3. The Service Provider shall not be liable for temporary unavailability of the Website due to maintenance work.

7.4. The Party that has failed to fulfill or improperly fulfilled its obligations under the Agreement is obliged to compensate the other Party for losses caused by such violations.

8. Term of the Offer

8.1. The Offer comes into effect from the moment of its publication on the Service Provider's Website and remains valid until its withdrawal by the Service Provider.

8.2. The Service Provider reserves the right to amend the terms of the Offer and/or withdraw the Offer at any time at its discretion. Information about changes to or withdrawal of the Offer is communicated to the Customer by posting on the Service Provider's Website, in the Customer's Personal Account, or by sending a corresponding notification to the email address provided by the Customer when concluding the Agreement or during its execution.

8.3. The Agreement comes into effect from the moment of acceptance of the Offer terms by the Customer and remains valid until the Parties fully fulfill their obligations under the Agreement.

8.4. Changes made by the Service Provider to the Offer and published on the Website in the form of an updated Offer apply to Agreements concluded after their publication; to Agreements concluded earlier they apply only with the Customer's consent.

9. Additional Terms

9.1. The Agreement, its conclusion and execution are governed by the current legislation of the Russian Federation. All matters not regulated by this Offer or not fully regulated are governed in accordance with the substantive law of the Russian Federation.

9.2. In the event of a dispute, the Parties are obliged to resolve the dispute amicably before initiating court proceedings. Pre-trial dispute resolution is mandatory. Disputes or disagreements on which the Parties have not reached agreement shall be resolved in accordance with the legislation of the Russian Federation.

9.3. The language of the Agreement concluded under the terms of this Offer, as well as the language used in any interaction between the Parties (including correspondence, provision of requirements / notifications / clarifications, provision of documents, etc.), shall be Russian.

9.4. All documents to be provided in accordance with the terms of this Offer must be drawn up in Russian or have a translation into Russian certified in the prescribed manner.

9.5. The inaction of one of the Parties in the event of a breach of the terms of this Offer does not deprive the interested Party of the right to protect its interests later, nor does it constitute a waiver of its rights in the event of similar or comparable violations by one of the Parties in the future.

9.6. If the Service Provider's Website contains links to other websites and materials of third parties, such links are posted solely for informational purposes, and the Service Provider has no control over the content of such sites or materials. The Service Provider shall not be liable for any losses or damages that may arise from the use of such links.

10. Third-Party Software

10.1. For positions with no data in the games database, move evaluation is performed by the Stockfish 18 chess engine, which is downloaded into the Customer's browser and runs on the Customer's device. The moves and evaluations shown in this case are the result of the engine's calculation, not statistics of games played.

10.2. The engine is downloaded only after the Customer's explicit consent and is distributed under the GNU General Public License version 3 (GPLv3). The engine is used without modification.

10.3. Copyright notices, links to the source code and the full text of the license are provided at https://debutario.app/licenses.

11. Service Provider Details

Self-employed Lekomtsev Sergei Petrovich TIN (INN): 183310579475 Email: support@debutario.app Website: https://debutario.app/