Mastrly — terms of service

acceptance

Who these terms apply to

These terms (the “Terms”) form a binding agreement between you (the “Customer”, “you”) and Mark Hammond, a sole trader based in the United Kingdom (“Mastrly”, “we”, “us”), the operator of the Mastrly software and the mastrly.cloud and auth.mastrly.cloud websites (together, the “Service”).

By signing in to Mastrly, deploying the Mastrly bundle, or allowing your clients to use a Mastrly listener link, you accept these Terms. If you don’t accept them, don’t use the Service.

The Service is intended for professional use by audio mix and mastering studios and similar businesses. It is not directed at consumers.

what Mastrly is

Scope of the Service

Mastrly is a static web bundle that runs entirely in your browser. It uses your Dropbox or Google account to read and write files in a single workspace folder (named /mastrly) inside your own Dropbox or Google Drive, plus a hidden per-app sandbox provided by Dropbox or Google. It does not run a backend that stores your audio, your tokens, or your activity.

The only Mastrly-operated infrastructure is:

The marketing site at mastrly.cloud, which serves this page and the documentation.
A static OAuth callback page at auth.mastrly.cloud, which forwards Dropbox or Google sign-in responses back to licensed Mastrly origins. It has no server-side logic, no database, and processes nothing on your behalf.
A licensed-origins allow-list (licensed-origins.json) that controls which Mastrly deployments the callback will forward to.

Everything else — your mixes and masters, your project metadata, your listener share manifests — lives in your own Dropbox or Google Drive and your own browser.

licence

Your licence

Subject to these Terms and your payment of any applicable licence fee, Mastrly grants a non-exclusive, non-transferable, non-sublicensable licence to a single named individual (the “Licensed User”) to deploy and use the Mastrly software on a single internet origin (e.g. masters.yourstudio.com) for that individual’s own mix and mastering work.

Each licence is issued to one named person and keyed to a specific origin enrolled in the Mastrly licensed-origins allow-list. The licence:

is held by, and may only be used by, the Licensed User named on the order or invoice — it is not a studio-wide or seat-pooled licence, and credentials may not be shared with assistants, employees, contractors, or other engineers;
covers an unlimited number of clients, projects, and listener links handled personally by the Licensed User;
does not grant any right to redistribute the Mastrly software, or sell it as a service to third parties;
does not transfer any intellectual property in the Mastrly software, brand, source, or design.

Additional engineers working at the same studio each require their own named licence. Contact us if you need to transfer a licence to a different individual — transfers are at our discretion and may not be used to circumvent the named-user restriction.

The licence continues indefinitely unless terminated under these Terms (see Termination). If it is terminated, your origin will be removed from the allow-list and the auth callback will stop completing sign-ins for that origin. Files already in your Dropbox or Google Drive remain in place — Mastrly can’t and doesn’t touch them.

listener links

Listener links

The Licensed User may generate listener links to share masters. Anyone with a link can stream the referenced audio in the in-browser player, and links can be shared onward without restriction — Mastrly does not authenticate or identify the people who use them. The Licensed User can revoke a link at any time from inside Mastrly, and links stop working if the Licensed User’s licence is terminated.

People who open a listener link are not parties to these Terms. To the maximum extent permitted by law, Mastrly makes no warranties and accepts no liability of any kind to anyone who uses the Service through a listener link, however they obtained it.

acceptable use

Acceptable use

You agree not to use the Service to:

reverse engineer, decompile, disassemble, derive or attempt to derive the source code of the Mastrly software, or create derivative works based on it, except to the extent applicable law expressly permits such activity notwithstanding this prohibition (in the United Kingdom, the limited rights granted by sections 50B and 50BA of the Copyright, Designs and Patents Act 1988);
circumvent the licensed-origins allow-list, the auth callback, or any technical protection in the Mastrly software, or operate or attempt to operate an unlicensed Mastrly origin;
misuse the Dropbox or Google APIs or violate either provider’s API terms — namely Google’s API Terms of Service and User Data Policy, or Dropbox’s API Terms of Service and Branding Guidelines.

You are responsible for the content you place into your Mastrly workspace and for the listener links you generate. Listener links can be revoked at any time from inside Mastrly.

your account & data

Your account, storage, and data

Using Mastrly requires either a Dropbox or a Google account. Your relationship with that provider — including storage, account security, billing for paid tiers, and data retention — is governed by your agreement with the provider, not by these Terms.

Your audio masters and project files are stored in your own Dropbox or Google Drive. We don’t hold them, copy them, or transmit them through any Mastrly-controlled server. You are solely responsible for:

backing up your Dropbox or Google Drive contents if you need backups;
controlling who has access to your Dropbox or Google account;
complying with any contractual obligations you owe to your own clients (e.g. confidentiality of unreleased material).

How Mastrly handles the limited Dropbox or Google data it touches is described in the privacy policy, which is incorporated into these Terms by reference.

deployment

Self-hosted deployment

Mastrly is delivered as a static bundle that you host yourself (on Cloudflare Pages, Netlify, your own server, etc.). You are responsible for your hosting, your DNS, your TLS certificate, and any logs, terms, or privacy obligations of the host you choose.

We’ll publish updated builds from time to time. You decide when to deploy them. We don’t push code into your deployment. Your licence key covers every release of the major version it was issued for (currently Mastrly 1.x); a future major version would require an upgraded key.

availability

Availability & changes

Because Mastrly runs in your browser against your Dropbox or Google Drive, the software keeps working even when Mastrly-operated infrastructure is offline — with one exception: signing in for the first time on a new origin or after a token expiry depends on the auth.mastrly.cloud callback being reachable.

We aim to keep auth.mastrly.cloud available, but we don’t guarantee a particular uptime, response time, or recovery time. We may change, suspend, or discontinue parts of the Service when we need to — for security, compliance, maintenance, or because the underlying Dropbox or Google APIs change. Where a change materially affects licensed customers, we’ll give reasonable notice by email and on mastrly.cloud.

fees

Fees and refunds

The licence fee and any included support are set out in the order, invoice, or quote we agree with you in writing. Unless otherwise agreed:

the licence is granted on payment of a one-time fee — it is perpetual, with no fixed term, no subscription, and no recurring or renewal charge;
fees are payable in full before the licence is issued and your origin is enrolled in the allow-list;
fees are exclusive of any taxes, which you are responsible for if applicable;
once the licence has been issued, fees are non-refundable except where required by law.

intellectual property

Intellectual property

The Mastrly software, source code, design, brand, and documentation are owned by Mark Hammond and protected by intellectual-property law. Nothing in these Terms transfers any ownership to you. Your licence is a permission to use the software, not a sale of it.

Mastrly is proprietary, closed-source commercial software. It is not released under any open-source or free-software licence, and the fact that the in-browser bundle is delivered as readable JavaScript and CSS does not place it in the public domain or grant any right to copy, modify, redistribute, or re-host it. All rights in the software not expressly granted to you in these Terms are reserved by Mark Hammond.

You retain all rights in the audio you put through Mastrly. We don’t claim any ownership, licence, or other rights over your audio or your clients’ audio. We don’t use it to train machine-learning models. We don’t analyse it.

If you send us feedback or suggestions, we may use that feedback to improve Mastrly without obligation to you.

warranty disclaimer

Warranty disclaimer

To the maximum extent permitted by law, the Service is provided “as is” and “as available”. We make no warranties — express, implied, or statutory — including warranties of merchantability, fitness for a particular purpose, non-infringement, or that the Service will be uninterrupted, error-free, or free of harmful components. We do not warrant that the Service will meet your specific requirements or that any defect will be corrected.

You are responsible for evaluating Mastrly’s suitability for your studio before relying on it for client deliveries.

limitation of liability

Limitation of liability

To the maximum extent permitted by law:

we will not be liable for any indirect, incidental, consequential, special, exemplary, or punitive damages, or for lost profits, lost revenue, lost data, lost goodwill, or business interruption, arising out of or relating to your use of (or inability to use) the Service, even if we’ve been advised of the possibility of such damages;
Mastrly’s access to your cloud storage is bounded to its workspace folder by the OAuth scopes it requests (Google’s drive.file scope; Dropbox’s App folder mode), so it cannot read, modify, or delete any file outside that folder. Within the workspace folder, however, Mastrly issues delete, move, overwrite, and rename operations as part of its normal function, and through user action, user error, or software defect may irrecoverably delete or alter files. You must not treat your Dropbox or Google Drive as a backup store for files in Mastrly. We accept no liability for any such loss, and you are solely responsible for maintaining independent backups of any audio, metadata, or other content you place into Mastrly;
your relationship with Dropbox or Google — including storage quota, account standing, billing, and payment of any fees those providers charge — is solely between you and that provider. We are not liable if your access to or use of Mastrly is degraded, interrupted, or prevented because of issues with your provider account, including suspended accounts, exhausted quota, unpaid bills, or provider-imposed rate limits; and
our total aggregate liability under or in connection with these Terms, however arising (in contract, tort, including negligence, breach of statutory duty, or otherwise), is limited to the licence fees you actually paid to Mastrly in the twelve (12) months preceding the event giving rise to the claim.

Nothing in these Terms limits any liability that cannot be limited under applicable law — including liability for death or personal injury caused by negligence, or for fraud or fraudulent misrepresentation.

your indemnity

Indemnity

You will defend, indemnify, and hold harmless Mark Hammond against any third-party claims, damages, losses, and reasonable expenses (including legal fees) arising out of or relating to: (a) the audio or other content you process or distribute through the Service; (b) your breach of these Terms or applicable law; or (c) your use of the Service in a way that infringes a third party’s rights.

termination

Termination

You can stop using the Service at any time. To fully detach, revoke Mastrly’s access at myaccount.google.com/permissions and clear your browser data on the Mastrly origin.

We may suspend or terminate your licence, your origin’s presence in the allow-list, and your access to the auth callback if you materially breach these Terms (including the acceptable-use rules) and don’t cure the breach within fourteen (14) days of written notice, or immediately if the breach is one that can’t reasonably be cured.

Sections that by their nature should survive termination (licence restrictions, intellectual property, warranty disclaimer, limitation of liability, indemnity, governing law) will survive.

changes

Changes to these terms

When these Terms change materially, the effective date at the top will be updated and a note will appear on the Mastrly home page for at least thirty days. If you keep using the Service after the change takes effect, you accept the updated Terms.

governing law

Governing law & disputes

These Terms are governed by the laws of England and Wales. The courts of England and Wales have exclusive jurisdiction over any dispute arising out of or relating to these Terms or the Service, except that we may seek injunctive relief in any competent court to protect our intellectual property or confidential information.

miscellaneous

Miscellaneous

Entire agreement: these Terms, together with the privacy policy and your order/invoice, are the entire agreement between you and Mastrly about the Service.
No waiver: our not enforcing a right at any moment doesn’t waive that right later.
Severability: if any clause is found unenforceable, the rest stays in effect.
Assignment: you can’t assign these Terms without our written consent. We may assign them in connection with a transfer of the Mastrly business.
No third-party rights: these Terms create no rights for anyone other than you and Mastrly.

contact

Contact

Mastrly is operated by Mark Hammond, a sole trader based in the United Kingdom. Questions about these Terms, licence enquiries, and notices: hello@mastrly.cloud.

The agreement between you and Mastrly.