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Terms of Service (Public Offer)

Last updated: 2 October 2026

This English text is a translation provided for convenience. The legally binding document is the Russian version; if the two differ, the Russian version prevails.

General provisions

This document is a public offer within the meaning of Article 437(2) of the Civil Code of the Russian Federation ("the Civil Code"): an offer to enter into a contract for paid services, on the terms below, with anyone who accepts it ("the Contract").

The provider ("we"): the person whose details are published on the Contacts page. The S1 solutions service ("the service") consists of the website https://s1solutions.pro, the dashboard and the application programming interface (API).

The customer ("you") is an individual with legal capacity, an individual entrepreneur or a legal entity that has accepted the offer. A consumer is a customer who is an individual using the service solely for personal, family, household or other needs not connected with business. People under 18 may use the service only where and as the law allows, including with the consent of their legal representatives where it is required.

The offer is accepted (Article 438 of the Civil Code) when you do any of the following: register an account and tick the box accepting the offer; pay for services on the terms agreed with the provider; start a free demo conversion. The time you accepted the offer at registration is kept in your account. The written form of the Contract is deemed to be observed.

The Acceptable Use Policy and the Refund Policy are integral parts of the Contract. What the service stores and what it does not collect is described in the Privacy Policy. If you do not agree with the terms, do not use the service.

Subject of the Contract

At your request, we provide an automated audio processing service: you upload a song and a short voice sample; the service uses machine-learning algorithms to convert the vocal part of the song so that it sounds in the voice from the sample, and returns the track after mixing and mastering ("the result"). You pay for the service as set out in the Contract.

The service is fully automated and is used through the API (asynchronous jobs) and the dashboard. We do not select, listen to, edit or review the content of uploaded files or results, and we do not distribute them.

A free demo is available on the home page: a visitor without an account can upload a song and a voice sample and receive the converted track. The number of demo runs from one network address is limited. The Contract applies to the demo, except for its payment terms.

Your account and API keys

Paid use of the service requires an account. It is created with a nickname and a password that you make up yourself. You do not need to give an email address, a phone number, your name or anything else about yourself, and the service does not ask for them. Do not use your name, email address or anything else you could be recognised by as your nickname.

Recovery code. When you register, you are shown a recovery code once. Keep it somewhere safe: the service stores only a hash of the code and cannot show it again. If you forget your password, write to support and give your nickname and the recovery code — the password will be reset. The code is single-use and stops working once it has been used.

Without the recovery code, access to the account and its remaining balance cannot be restored. The service does not know who an account belongs to and has no other way to make sure that the person asking is its owner. This follows from the service not collecting information about its users; by accepting the offer you confirm that you understand and accept this risk. This does not take away your right to claim a refund of unspent prepayment: how to confirm it is described in the Refund Policy.

You create API keys in the dashboard. A key is shown once, when it is created, and can be revoked at any time. Keep your password and keys secret and tell us if they may have become known to others. Actions performed with your password, key or recovery code are treated as yours until you tell us you have lost control of them; this does not prevent you from proving otherwise and does not apply where outsiders gained access through our fault.

Price and payment

The price shown on the site and in the API documentation is $0.10 (US dollars) per minute of the source track, billed per second. That price applies unless the provider and the customer have agreed a different price individually in writing, including by email or in a messenger. The price in force when a job is started does not change for that job.

Ordering and payment are by arrangement with the provider. The customer contacts the provider using the details on the site, and the parties agree the volume of services, the price, and the method and time of payment. There is no online payment on the site. After the agreed payment is received, the provider credits the corresponding amount to the balance of the customer's account.

Services are paid for in advance. The balance, reserves and charges are kept in US dollars as units of account. The balance shows the amount of prepayment for services not yet provided; it is not electronic money, bears no interest and can be used only to pay for the service.

If the customer is a resident of the Russian Federation, amounts in US dollars serve to determine the size of the obligation, while payment and refunds are made in the currency of the Russian Federation, in the amount equivalent to the US dollar amount at the official Bank of Russia exchange rate on the day of payment, unless the parties have agreed a different rate or a different date for determining it (Article 317(2) of the Civil Code). Before payment, the provider tells such a customer the amount to be paid. With other customers, settlements are made in the currency and by the method agreed by the parties and permitted by the law of the Russian Federation.

A payment document is issued to the customer in the cases and in the manner required by Russian law.

When you start a job, the cost of processing a track of the maximum length (10 minutes) is reserved on your balance. If the job succeeds, the actual cost is charged and the reserve is released. If the job fails, the reserve is released and nothing is charged. A job cannot be started if your balance does not cover the reserve.

The service for a particular job is considered provided at the moment the job completes successfully and the result becomes available for download. The history of credits, reserves and charges is available in the dashboard.

Limits and delivery of the result

  • A track can be up to 10 minutes long. Each uploaded file can be up to 200 MB.
  • The result is available for download for 5 minutes after the job is completed. After that it is deleted and cannot be downloaded or restored.
  • Uploaded files are deleted when the job reaches a final state (success or failure). No copies are kept, and we cannot return them to you.
  • When the service is busy, it may temporarily refuse to start new jobs. Nothing is reserved or charged in that case.

Downloading the result in time is your responsibility. These periods and limits are essential properties of the service, of which you are informed before the Contract is made.

Your content and the result

All rights to the files you upload remain with you or their rightsholders. You permit us to perform on the uploaded files only the technical operations (storing in memory, reproduction, processing) needed to carry out the job you started, and only while the job runs and the result is kept.

By starting a job you give us the following assurances (Article 431.2 of the Civil Code):

  • you are the rightsholder or have obtained the necessary permissions to use the musical work (music and lyrics), the performance and the phonogram, including permission to adapt them, to the extent needed to create and then use the result (Articles 1229, 1270, 1317 and 1324 of the Civil Code);
  • the voice in the sample is your own, or you have the consent of the person it belongs to for this use of their voice, including the processing of the recording of their voice by the service;
  • uploading the files and using the result does not break the law or the rights of third parties.

We acquire and claim no rights in the uploaded files or in the result. As between you and us, any rights that may arise in the result belong to you; using the result may nevertheless require permissions from the rightsholders of the source material and the consent of the person whose voice was used. We do not guarantee that the result is a protected object of intellectual property.

You decide how to use the result and are responsible for that, including stating that the voice was converted where the law, a platform's rules or ordinary good faith towards listeners require it.

Acceptable use

You undertake to follow the Acceptable Use Policy. In particular, you may not use the service to break the law or the rights of third parties, to impersonate another person without their consent, for fraud, harassment or deception, or upload material protected by technical protection measures that you are not entitled to circumvent.

If you give your own users access to the service (for example, by building the API into your product), you must make sure they follow these rules, and you answer to us for their actions as for your own.

Quality and availability

We provide the service as it is described on the site and in the documentation. The result is produced automatically and depends on the material you upload: the quality of the recording, the cleanliness of the voice sample, the genre and other features. We do not promise that the result will match your subjective artistic expectations or be fit for a specific purpose we were not told about.

The service may be temporarily unavailable because of maintenance, failures or high load; we do not guarantee any particular level of uninterrupted operation. A job that was not completed is not charged.

These provisions do not limit the rights a consumer has on discovering defects in a service provided, under Article 29 of the Law of the Russian Federation "On Protection of Consumer Rights" ("the Consumer Protection Law"). How to make such claims is described in the Refund Policy.

Liability

The parties are liable for failing to perform the Contract, or performing it improperly, in accordance with the law of the Russian Federation.

Towards a consumer, we are liable to the extent and on the terms set by law; nothing in the Contract excludes or limits that liability or is to be read as doing so.

Towards a customer who is not a consumer, we are liable only for actual damage and within the amount that customer paid for services during the three months before the breach; lost profit is not compensated. This limit does not apply to an intentional breach (Article 401(4) of the Civil Code).

We do not determine the content of uploaded material or how the result is used, and we are not responsible for the customer's actions. If, because you breached your assurances or the Acceptable Use Policy, claims are brought against us by third parties or public authorities, you must compensate the resulting losses as provided by law.

A party is released from liability if it proves that proper performance was impossible because of force majeure (Article 401(3) of the Civil Code).

Suspension and termination

You may withdraw from the Contract at any time (Article 782(1) of the Civil Code, Article 32 of the Consumer Protection Law): stop using the service, ask us to close your account and refund your unused balance. The procedure is in the Refund Policy.

We may suspend the start of new jobs in an account if there is well-founded information about a breach of the Contract or the Acceptable Use Policy, including a complaint from a rightsholder or from a person whose voice was used, or if the law or a decision of a public authority binding on us requires it. We tell the customer the reason for the suspension on request and consider the explanations and documents the customer provides.

We may withdraw from the Contract in the cases and in the manner provided by law (Article 782(2) of the Civil Code). When the Contract ends for any reason, the unused balance is returned to the customer.

Complaints from rightsholders and others

If you believe the service was used to infringe your copyright or related rights, or to use your voice without consent, send a notice as described in the "Complaints and how we handle them" section of the Acceptable Use Policy.

Personal data

The service is built so as not to collect personal data: an account is not linked to a person, and no email addresses, phone numbers or IP addresses are stored. The cases in which personal data may still reach us (messages to support, a recording of a recognisable person's voice while it is being processed, payment details) and your rights are described in the Privacy Policy. In those cases we act in accordance with Federal Law No. 152-FZ of 27 July 2006 "On Personal Data".

If another person's voice is heard in a recording you upload, you pass it to us for processing on your instruction and confirm that you have a lawful basis for doing so.

Changes to the terms

We may publish a new version of the offer, the policies and the Refund Policy, and change the price. The date of the version is shown at the top of the document. A new version applies to payments and jobs made after it is published; by making them you accept the new version.

Changes do not affect services already provided and do not worsen the conditions for refunding prepayments already made. If you do not agree with a new version, you may withdraw from the Contract and receive your unused balance.

Governing law and disputes

The Contract is governed by the law of the Russian Federation. If a consumer lives in another country, the choice of Russian law does not deprive them of the protection given by the mandatory rules of the law of their country of residence, in the cases provided for by Article 1212 of the Civil Code.

Please write to us first — most questions are settled by correspondence. For a consumer, a pre-trial procedure is not mandatory; a consumer may bring a claim in the court of their choice under Article 17(2) of the Consumer Protection Law, including the court at their place of residence or stay.

For customers who are not consumers, a claim procedure is mandatory: a dispute may be taken to court thirty calendar days after the claim is sent. Such disputes are heard by the commercial (arbitrazh) court at the provider's place of registration.

Language

The Contract is made in Russian. The English translation is provided for convenience; if the Russian and English texts differ, the Russian text applies.

Provider and contact

Provider: the person whose details are published on the Contacts page.

For questions about the Contract, contact us by email at s1ckasfukml@gmail.com or on Telegram at @conv_support. Full details are on the Contacts page.