MasterX — legal notice, privacy and terms
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Legal notice, privacy and terms.

Everything that governs the sale and the use of MasterX, on one page: who publishes the software, what data is handled and under which conditions a licence is granted.

Legal notice Privacy policy Terms of use

02 — Privacy policy

What we collect, and what we never do with it

Updated on 12 October 2026.

Data collected

  • Your email address and the name used for the order, to create and deliver the licence.
  • The machine activation associated with your licence, to enforce the number of authorised computers.
  • The files you choose to send us for manual processing or for a support request.
  • Project files, saved versions and project metadata synchronised with your MasterX account, plus messages and attachments submitted through in-app support. Community posts and replies are visible to the users who can access the corresponding discussion.
  • Support messages exchanged by email or WhatsApp.
  • At each start of the application and each licence check: the date and time, the authorised computer, identified by one-way hashes of hardware characteristics and never by the characteristics themselves, the IP address, and the approximate location (city, region, country) and internet provider derived from it.
  • The ratings and reviews you publish in the application.
  • For cryptocurrency payments agreed with professional customers: the amount, date and network of the transaction, as shown in the payment confirmation.

Payment

Website payments are processed by Stripe. Card details are entered with Stripe; MasterX does not store full card numbers. For professional bank transfers, the information needed to match payments and prepare invoices is processed by MasterX and its business account provider Legalstart.

Why we hold it

MasterX (SASU), identified in the legal notice, is the data controller. Data needed for activation, licence management and support is processed to perform the contract or respond to a pre-contractual request. Files and exchanges are retained to return support files to customers and make changes needed to follow up their requests. Invoicing and accounting processing is based on MasterX’s legal obligations. Information strictly needed to prevent abuse or defend a legal claim may be processed on the basis of MasterX’s legitimate interests, with due regard to individual rights. Data is not sold to advertisers.

Connection data and device identifiers are used to enforce the number of authorised computers, detect the sharing of a licence and secure the service, on the basis of MasterX’s legitimate interests. These checks are automatic technical controls of the licence. An unauthorised computer may be blocked automatically and a licence suspended automatically; any final termination is decided after a review by MasterX, and the customer can present their observations. MasterX takes no final decision producing legal effects concerning a customer based solely on automated processing.

How long

Customer files and support messages are retained while the licence is valid to follow up requests. MasterX undertakes to delete them within 7 days after a licence expires without renewal. Customers should retain their own copies of delivered files.

This rule does not cover invoices and accounting documents retained for their statutory period, or information that must still be kept to handle a complaint or defend a legal claim. Such information is limited to what is necessary, with restricted access and retention limited to the applicable statutory period or resolution of the dispute. Requests for earlier erasure may be sent to the contact below.

Public activity in the application

When you export a file, the Live Solutions feed shows other users the ECU, the solutions applied and your user name masked after its first three letters. The reviews and ratings you publish are visible to other users under the same masked name.

Reviews in the application

Reviews and ratings are posted from within the application by licence holders, about the solutions they applied. They are published immediately with their date, without prior control. MasterX does not pay for reviews and does not publish reviews on behalf of customers. MasterX may reply publicly to a review. A review is removed only if it is insulting or unlawful, contains personal or confidential data, does not concern a MasterX solution, or duplicates another review; its author is informed of the reason. When a review reports a technical problem that MasterX has since corrected, the review remains published and MasterX may add a reply stating the correction.

Use of an AI assistant

MasterX uses artificial intelligence tools supplied by a specialised provider to help analyse support messages and correspondence, search the records needed to answer a request and prepare replies. Every reply and every decision is reviewed and taken by MasterX. Only the information needed for the request is used. The settings of the accounts used by MasterX do not allow the provider to use these exchanges to train its models, and the support assistant uses the provider’s programming interface, whose commercial terms exclude such use.

Recipients and hosting

Data is accessible to authorised MasterX staff and to the providers needed to operate the service: Supabase for files and the database, Netlify for the website, Stripe for online payments, Legalstart for the business account, Revolut for the receipt of cryptocurrency payments, Google for the masterxresolve@gmail.com mailbox, Resend for sending certain emails, WhatsApp (Meta) for WhatsApp exchanges, an artificial intelligence provider for the assistant described above, and MasterX’s accountant for invoicing and accounting. The MasterX Supabase project uses primary region eu-west-1, in Ireland (European Union). The website sets no advertising or tracking cookies. When enabled, Umami audience measurement counts visits and clicks (purchase, WhatsApp, ECU search) in aggregate, without cookies and without keeping your IP address.

The primary project region does not mean that all providers, subprocessors, maintenance access or messaging exchanges remain exclusively within the European Union. Google, Meta, Netlify, Stripe, Resend and the artificial intelligence provider may process data in the United States. These transfers rely on a mechanism permitted by the GDPR, as provided in the terms of each provider: the EU-US Data Privacy Framework or the standard contractual clauses of the European Commission. Contact masterxresolve@gmail.com for details.

Your rights

You may request access, rectification, erasure or restriction of processing by emailing masterxresolve@gmail.com. Subject to GDPR conditions, you also have rights to portability and to object to processing based on legitimate interests. Requests are normally answered within one month; any legally permitted extension is explained within that period.

A request to erase some data does not automatically terminate the licence. Where data is still needed to perform the contract, meet a legal obligation or defend a claim, MasterX explains the applicable limits and any consequences of closing the account. You may complain to the French data protection authority, CNIL, at www.cnil.fr.

03 — Terms of use

Version updated on 13 October 2026.

The conditions a licence is granted under

Customers, prices and payment

MasterX is sold exclusively to professionals (tuning companies, garages, workshops and self-employed tuners) for the needs of their business. By placing an order, the customer declares that they are purchasing as a professional, for their business activity.

Displayed prices are final amounts payable, inclusive of applicable taxes. Annual: €999 for 12 months, then €899/year on renewal before expiry. Monthly: €199 per month, with the same content as Annual (see “Monthly licence”). Annual Plus: €2,490, then €2,249/year before expiry. Ultimate Plus: €3,999, then €3,599/year before expiry. A licence purchased at the previous rates renews at €499, €1,399 or €2,999/year for Annual, Annual Plus or Ultimate Plus respectively if renewed before expiry; after expiry, the price of a new licence applies.

The order total is shown before payment. Professional customers may pay by bank transfer or on the website and provide their invoicing information by message. Sales are professional sales.

What the licence covers

A licence gives one holder the right to use MasterX for the paid period on the number of computers stated in the plan: one computer on Annual and Monthly, two on Annual Plus and Ultimate Plus. Annual, Monthly and Annual Plus cover cars and light commercial vehicles. Trucks, agricultural machines, motorbikes, industrial engines and boats are covered by Ultimate Plus only.

The content of each plan is the one described on the licences page on the day of the order. Functions are listed plan by plan; a function that is not listed for a plan is not included in it. The checksum module, technical support and manual processing are only included from Annual Plus.

Delivery

Delivery is digital. For payments made on the website through Stripe, the licence is activated after payment validation and credentials are normally emailed within minutes. For professionals paying by bank transfer, credentials are sent on the day the funds are actually received in the MasterX account. Proof that a transfer was initiated is not receipt of funds. Customers must provide a valid email address and the information needed for invoicing.

The licence is delivered, and its term starts, when the credentials are sent to the email address entered at the time of payment. Registering a computer with a code received by email is a separate technical step: it neither delays delivery nor the start of the licence. Non-receipt of the credentials must be reported within 7 days; MasterX then sends them again or, if delivery is impossible, refunds the payment.

Duration and renewal

An annual licence (Annual, Annual Plus, Ultimate Plus) runs for 12 months from delivery. Its renewal is not automatic and nothing is charged without your action: we email the renewal offer before expiry, at the published renewal price, and access simply ends if you do not take it.

The Monthly licence follows its own rules, described in “Monthly licence”.

Monthly licence

The Monthly licence costs €199 per month and gives the same rights as Annual: automatic solutions, 10 files per day, one computer, no technical support, no manual processing and no checksum module.

It is paid by card through Stripe. By confirming the payment, the customer authorises MasterX to charge this amount automatically every month, on the anniversary date of the first payment, to the payment method saved with Stripe, until the customer asks to stop. Each paid month gives access until the next due date. Stripe sends a receipt for every payment.

The customer can stop the Monthly licence at any time, without giving a reason and without any fee, by a written message from the email address or the account of the licence: to masterxresolve@gmail.com, through the Support section of the application or on WhatsApp at +262 692 11 43 17. MasterX confirms the stop by email within 48 hours. A request received at least 24 hours before the due date prevents the next charge; access remains open until the end of the month already paid.

A month that has started is due in full and is not refunded, in whole or in part. If a monthly payment fails, access is suspended until the payment is made. Any change to the monthly price is announced at least 30 days in advance by email and only applies to the following months; the customer can stop before it applies.

Upgrades and duplicate payments

Moving to a higher plan is charged at the price difference shown in the application or quoted in writing before payment, and keeps the current expiry date. A duplicate payment, or a plan bought by mistake, reported within 7 days and before any file has been exported or downloaded with it, is refunded or converted into the right plan.

Support and manual processing

Annual and Monthly include no technical support and no manual processing by our team: no manual file processing, no manual stage, no Restore ORI and no reply time. On every plan, questions about payment, delivery, account access, stopping the Monthly licence and legal matters are answered by email at masterxresolve@gmail.com. Annual Plus includes support, unlimited manual file processing and one manually prepared stage file per day; automatic stages are unlimited. Ultimate Plus includes support, unlimited manual files and unlimited manually prepared stages, with processing priority. Restore ORI is manual processing, available from Annual Plus. The checksum module is included in Annual Plus and Ultimate Plus; it is not included in Annual and Monthly.

Files that can be processed are generally handled within minutes: automatically on all licences, or by the team on plans that include manual processing. This usual turnaround is indicative. On Annual Plus and Ultimate Plus, the announced maximum time is 48 hours and 24 hours respectively, in calendar hours, 7 days a week. It runs from receipt of a complete request and a usable file, covers a first reasoned answer or the delivery of the file, and does not guarantee that a solution exists for every file: some files cannot be processed, in which case the customer is informed. It is suspended in case of force majeure, an outage of a provider, or while MasterX is waiting for information from the customer.

If MasterX exceeds this time for a reason attributable to it, the customer obtains on request a free extension of 3 days of licence per late request, up to 30 days per year. This extension is the only compensation due for support times.

New terms apply to purchases, renewals and monthly payments for which they have been accepted. Updating this page does not reduce rights already agreed for an active licence.

Respectful use of support, suspension and bans

Customers communicate courteously with the MasterX team and use support only for what their plan includes. The following are serious breaches: insults, threats, intimidation, harassment and discriminatory language, as well as pressure (such as threats of negative reviews, publication or payment disputes) intended to obtain a refund, an advantage, a solution or a service that the plan does not include.

The following are also breaches when they continue after a warning: sending messages in bulk, sending the same request through several channels (WhatsApp, email, chat, social media), repeating a question that has already received a clear answer, insisting on a solution, manual processing, turnaround time or service that the customer's plan does not include, and refusing to follow support instructions (the channel indicated, the file or information requested) while continuing to chase the team. A new question, reporting a problem or a written, courteous complaint is not a breach.

In the event of a serious breach, MasterX may immediately suspend access to the application and support and then terminate the licence automatically, without prior formal notice (article 1225 of the French Civil Code). For other breaches, MasterX sends a written warning, by email or by message in the application, which serves as formal notice; if the breach is repeated after that warning, the licence may be terminated automatically, without any further notice period. The decision and its reasons are notified in writing.

Termination deactivates the account and permanently bans the customer from all MasterX services (application, support, Damos, Server Files). The customer may not take out a new licence, whether directly, through a reseller or through another person or company; any account created to get around a ban is closed without refund. Amounts already paid are retained by MasterX, with no refund, pro rata, credit or token re-credit, as fixed compensation for the harm caused (disruption of support, team time, damage to its reputation), to the extent permitted by law.

MasterX's messages, screenshots and logs serve as evidence of the facts (see the Evidence section). The customer may submit written observations to masterxresolve@gmail.com; doing so does not suspend the measure.

How the software behaves

MasterX checks the loaded file against the requirements of each module. Availability depends on the ECU, software version and file contents; compatibility scores are interpreted according to the module, not a universal 100% threshold. The public list of supported ECUs shows possible coverage by ECU family at a given date: it does not mean that every listed function can be applied to every file. The availability of a solution is only confirmed by the analysis of the customer's file in MasterX; its absence for a given software version or file is neither a defect nor a breach and does not entitle the customer to a refund.

Depending on the ECU, a solution acts on maps, monitoring functions and limp modes. The notice delivered with each export sets out the procedure to follow, including any component to disconnect, and the result assumes that it is followed. The customer reviews the analysis in the application before buying a higher plan or applying a solution.

Modified files and checksum

Modified files are produced from the file supplied by the customer, in the state in which it was supplied. Every modified file, whether produced automatically, by the team or by the customer in the application, is a technical proposal that the customer is free to use or not. Unless the plan includes the checksum module (Annual Plus, Ultimate Plus), files are delivered without checksum correction: the customer must correct the checksum with their reading and writing tool, or another suitable tool, before writing to the ECU; otherwise the vehicle may not start.

Before writing, the customer checks the modified file and keeps a full backup of the original read. The customer alone decides to write a modified file to a vehicle and to deliver it to their own customer. A vehicle that does not start, a fault, a warning light or a limp mode caused by an uncorrected checksum, an incomplete or incorrect read, a file that had already been modified, the procedure of the notice not being followed, a fault already present on the vehicle, or the reading and writing equipment, is not a defect of MasterX.

Use of modified files at your own risk

Writing a modified file changes the behaviour of the engine and of the vehicle. The customer carries out this work under their sole professional responsibility and accepts its risks. To the extent permitted by law, MasterX is not liable for the consequences of writing or using a modified file, in particular: damage to the engine, turbocharger, gearbox, clutch, injection, exhaust or after-treatment system; a vehicle that does not start or runs in limp mode; loss of manufacturer warranty; failure of a technical inspection; fines, penalties or administrative consequences; and claims from the vehicle owner or any third party.

The customer checks every file before writing it, carries out the necessary tests before returning a vehicle, and restores the original file in case of doubt. The customer holds MasterX harmless against any claim made by their own customers or by third parties in connection with the work they carried out with MasterX, and bears the costs that MasterX would have to pay as a result, including reasonable lawyer, expert and court costs, unless the damage results from a gross or intentional fault of MasterX.

Computers and licence sharing

The licence is personal to its holder: it may not be shared, lent, resold or used for another company. It runs on one computer (Annual, Monthly) or on two computers of the same holder (Annual Plus, Ultimate Plus), the second one located within 50 km of the first when it is registered. Each computer is registered once with a code received by email, and one change of computer is allowed per 30-day period. An internet connection is required; there is no offline mode.

Computers are checked automatically. A computer that is not authorised is blocked. At the third refused computer, a warning is displayed in the application; at the fourth, the licence is suspended. MasterX then reviews the situation, informs the customer by email and lets them explain; the final termination of a licence for sharing is decided after that review and gives no right to a refund.

Prohibited uses, scraping and sharing

The following are prohibited: sharing, lending, renting or reselling the licence or login details, including through remote access; using robots, scripts, bots or extraction tools to query the application, the website or the servers; scraping or systematically copying files, solutions, Damos, A2L files, libraries or databases; reselling these contents or making them available to third parties; reverse engineering, decompiling or analysing the software and its exchanges with the servers; and circumventing the computer lock, quotas or any other protection measure. MasterX's contents, solutions and databases are protected by copyright and by the database producer's right (articles L341-1 et seq. of the French Intellectual Property Code).

An established prohibited use (for example sharing confirmed after the review described in the Computers and licence sharing section, or extraction detected in MasterX's logs) is a serious breach: MasterX may immediately suspend access and terminate the licence automatically, without prior formal notice, with the consequences set out in the Respectful use of support, suspension and bans section (permanent ban, no new licence, no refund). MasterX may also claim compensation for its loss, including the value of the files and contents extracted, and take any appropriate legal action.

Damos store and tokens

Tokens are prepaid units usable only in the Damos section of the application; one token corresponds to €1 including VAT at the time of purchase, for services whose price is shown before purchase. Tokens are not electronic money, have no cash value, cannot be exchanged, transferred or converted into money, and are not refunded once credited, except for a charging error attributable to MasterX or where the law requires it. Using them requires an active licence; an unused balance becomes usable again if the customer takes a new licence within 24 months.

Each file is described before purchase (brand, ECU, format and, when identified, software version). The customer checks that the file matches the vehicle, the ECU and the software before buying. A Damos, A2L or map pack (.kp) only works together with the matching original file, opened in the customer's own software; an automatically generated A2L is a map identification aid and may be incomplete. A purchase in tokens is final as soon as the file is made available. A file that cannot be used for the reference announced in its description, reported within 7 days with the file concerned, is replaced or its tokens are credited back. Purchases remain downloadable while the licence is valid; the customer keeps a copy.

Server Files and libraries

Original files, definitions and libraries made available in the application are reference material, provided as they are. The customer checks that a file matches their vehicle before using it and always works from the original file read from the vehicle concerned. Downloads follow the daily quota of the plan.

Your responsibility

MasterX is a technical tool sold exclusively to professionals. You remain responsible for the legality of the work you carry out in your country, for the road-legal status of any vehicle you modify, for taking a full backup before writing, and for the equipment used to read and write the ECU.

Solutions that affect emission control systems (for example DPF, EGR, AdBlue/SCR, catalyst or lambda) are intended for competition, track or off-road vehicles. Removing or disabling them on a vehicle used on public roads is prohibited in France (article L318-3 of the Highway Code) and in most countries. The customer undertakes to use them lawfully and holds MasterX harmless against any claim, fine, administrative penalty or conviction arising from their use or from the use made by their customers, and reimburses any sums MasterX would have to pay as a result, including lawyer, expert and court costs.

A solution that affects an emission control system increases the vehicle's emissions and may lead to a failed technical inspection or roadside check, warning lights, fault codes, limp mode, loss of warranty and the impossibility of making the vehicle compliant again without the original file and original parts. The customer informs their own customer of these consequences before the work and keeps the original file so that it can be restored.

Immobiliser and vehicle authorisation

Immobiliser (IMMO) functions are reserved for repairing or replacing an ECU on a vehicle whose owner the customer has verified and who has authorised the work. The customer keeps this proof and shows it on request, and never works on a vehicle of doubtful origin. MasterX may suspend or terminate, without refund, a licence used for an unlawful purpose.

Payment disputes

Before opening a payment dispute with their bank, the customer contacts MasterX at masterxresolve@gmail.com so that the problem can be solved. A good-faith payment dispute or refund request is not, by itself, fraud or grounds for a ban. MasterX reviews the transaction evidence and allows the customer to provide an explanation.

A knowingly false claim that a transaction was unauthorised, not received or cancelled, for a service that was delivered or used, established by objective evidence, is a serious breach. MasterX then provides its evidence to the bank and may suspend the licence until the dispute is closed. Any measures are reasoned, proportionate and applied in accordance with the suspension and termination rules and applicable law. Only amounts actually owed may be recovered.

Limits of liability

MasterX has a best-efforts obligation. Customers must use suitable equipment, verify compatibility and keep a backup before writing. MasterX is not liable for damage to the extent that it results from misuse, from the customer's equipment or from a cause not attributable to MasterX. MasterX is not liable for indirect loss, such as loss of business, customers or revenue, vehicle downtime, towing, repairs following a write carried out by the customer, or compensation paid to an end customer.

MasterX does not guarantee any particular result, power gain or compatibility with a given vehicle, nor uninterrupted availability: the application, its libraries and its servers are updated continuously and may be temporarily unavailable for maintenance or for reasons beyond MasterX's control.

MasterX's total liability, for all causes combined, is limited to the amounts actually paid by the customer to MasterX during the 12 months preceding the event giving rise to the claim. These limits do not apply in the event of gross negligence, wilful misconduct or personal injury, and this clause does not deprive an essential obligation of its substance. Virtual Dyno curves are references from the MasterX database, not measurements of the loaded vehicle or a performance guarantee.

Updates and end of service

MasterX releases regular updates during the licence, with no guaranteed frequency or content, and may change or withdraw a function for technical, legal or security reasons. If the service ends permanently before an annual licence expires, the customer is refunded pro rata for the remaining full months, with no further compensation.

Resellers

A licence activated by an authorised reseller on proof of transfer is provisional until the funds are actually received by MasterX, and is suspended if they are not received within 5 business days. The reseller only sells to professionals, has them accept these terms and handles the refund requests of its own customers.

Professional customers

MasterX licences are sold exclusively to professionals for the needs of their business activity. When ordering, the customer declares that they act as a professional and that the licence is purchased for that activity. On request, the customer provides their company name and registration number (SIRET, VAT number or foreign equivalent); failing that, MasterX may cancel the order and refund it before the credentials are sent.

The licence is delivered and the service begins as soon as the credentials are sent. No cancellation or refund is possible after delivery. A customer who falsely declares a professional status bears the consequences, and MasterX may rely on that declaration. Should the customer nevertheless be a consumer, they expressly request immediate access to the digital content as soon as the credentials are sent and acknowledge that they lose their right of withdrawal from that moment (article L221-28, 13° of the French Consumer Code).

Refunds

No refund is granted after the delivery of a licence, for a month of the Monthly licence that has started, or for tokens already credited or files already delivered, except in the cases provided for in these terms. This policy does not exclude repayments legally due in the event of non-performance attributable to MasterX or of a payment not owed. Complaints should be sent to masterxresolve@gmail.com with the licence reference and relevant supporting information.

Entire agreement

The contract consists of these terms, the description of the plan on the licences page on the day of the order and the invoice, which replace any previous exchange. Messages exchanged before or after the purchase (WhatsApp, email, chat, forum, social networks) are information given in good faith about a general situation; they do not modify the contract and create no additional commitment, function or deadline, unless MasterX agrees to it in writing from masterxresolve@gmail.com as an addition to the order. In case of contradiction, these terms prevail over marketing pages.

Evidence

The customer and MasterX agree that the records of MasterX's systems and of its providers (in particular Stripe, Supabase and Resend) are proof, unless proven otherwise, of the sending of the credentials, of connections, of registered computers, of analysed files, of applied and exported solutions, of downloads, of tokens used and of support exchanges, and that they may be produced in a payment dispute or in legal proceedings.

Acceptance, language and changes

The customer accepts these terms when placing the order, in particular by ticking the acceptance box on the payment page or by paying; the version accepted is the one published on the day of the order. These terms are written in French and translated into English; in case of difference, the French version prevails. MasterX may update them; the new version applies to purchases, renewals and monthly payments made after its publication, the customer being able to stop the Monthly licence before it applies.

Governing lawFrench law
Competent courtsCourts of Paris, France, including for interim relief, third-party claims or multiple defendants, unless a mandatory rule of jurisdiction provides otherwise
Data transfersSee “Recipients and hosting”
Contract languageFrench version prevails