Rostra

End User Licence Agreement

Last updated: 31 July 2026

This agreement covers what you may and may not do with the Rostra software itself. Our Terms of Use cover everything else, and our Privacy Policy covers your data. It is written to be read — if anything is unclear, email us and we will explain it plainly.

By installing or using Rostra you agree to it. If you do not agree, do not install or use Rostra, and if you have paid for a licence you may request a refund under clause 8.

1. Who you are dealing with

Rostra is published by Splendid Edge Systems, a registered sole proprietorship based in Ghana ("we", "us", "our"). Rostra is a brand and product of Splendid Edge Systems.

Support: support@userostra.com
Phone: +233 55 997 0100 (Ghana) · +1 251 901 4675 (US)
We aim to answer support email within two business days.

2. Definitions

  • Software — the Rostra application for macOS and Windows, including the bundled speech model, voice packs, pronunciation data, engine, user interface, and any updates we make available to you.
  • Free version — the Software used without a valid licence key: a limited set of voices and unlimited offline reading, at no cost and for an unlimited time.
  • Pro — the features unlocked by a valid licence key, as described on the Pro page at the time of your purchase.
  • Licence key — the credential we issue on purchase that activates Pro.
  • Major version — a release whose first version number differs. All 1.x releases are one major version; 2.0 begins the next.
  • Device — a single computer that you own or control.
  • You — the individual or organisation accepting this agreement. If you accept on behalf of an organisation, you confirm you have authority to bind it.

3. Your licence

The Software is licensed, not sold. We grant you a personal, non-exclusive, non-transferable, non-sublicensable licence to install and use it, subject to this agreement.

  • Pro is perpetual for the major version you purchased and may be activated on up to three devices that you own or control. You may use it for your own personal or business purposes.
  • The free version may be used indefinitely at no cost, on any number of devices you own or control.
  • Backups. You may make a reasonable number of copies for backup and archival purposes.
  • Your content is yours. You may use the speech Rostra generates for any lawful purpose, personal or commercial. We claim no rights in the text you convert or the audio you produce.

4. Restrictions

Except as clause 3 expressly permits, or as clause 4.1 preserves, you may not:

  • copy, publish, redistribute, resell, rent, lease, lend, sublicense or otherwise transfer the Software or any part of it;
  • share, publish, resell or transfer your licence key, or use it on more devices than clause 3 permits;
  • reverse engineer, decompile, disassemble, decrypt, extract, or otherwise attempt to derive the source code, algorithms, model weights or internal structure of the Software;
  • modify, adapt, translate or create derivative works of the Software;
  • circumvent, disable or interfere with any licensing, activation or protection mechanism, or use the Software with any tool intended to do so;
  • remove, obscure or alter any copyright, trademark, attribution or other proprietary notice; or
  • use the Software to build a competing product, or to train a machine learning model on its outputs for that purpose.

4.1 What this clause does not take away

Nothing in clause 4 limits any right you have that cannot be limited by agreement under the law that applies to you. In particular, if you are in the European Union or the United Kingdom, nothing in clause 4 restricts your rights to observe, study, test or decompile the Software to the extent permitted by Articles 5 and 6 of Directive 2009/24/EC or its national implementations.

Nothing in clause 4 applies to the third-party or upstream components listed in clause 10, which carry their own licences. Where those licences grant you rights, you have them.

5. What you get, and what may change

  • All updates within your major version are included at no extra cost.
  • A future major version may be an optional paid upgrade. We are not obliged to provide one, or to provide it free.
  • We will not remove features you have already paid for.
  • Speech synthesis runs entirely on your device. The Software does not send the text you read anywhere — see the Privacy Policy.

6. Licence keys, activation and revocation

When you activate Pro, the Software sends your licence key and a one-way hash of your device's hardware identifier — never the identifier itself, and no personal data — to our server, to confirm the licence and how many devices it is used on. Afterwards the licence is verified offline on your device, with a re-check roughly every 30 days. There are no user accounts.

You are responsible for keeping your licence key confidential.

We may deactivate or revoke a licence key where:

  • the purchase was refunded, reversed or charged back;
  • the key is being shared, resold, or used on more devices than clause 3 permits; or
  • the purchase was fraudulent.

Outside those cases, a licence you have paid for is yours to keep. We will not revoke a licence to force an upgrade.

7. Acceptable use

You are responsible for the text you convert to speech and for how you use the audio. You confirm you hold the rights necessary for the text you select. You must not use the Software:

  • to infringe anyone's copyright or other rights;
  • to impersonate a real person, or to create audio presented as a real person's genuine speech; or
  • for any unlawful purpose.

8. Purchases, taxes and refunds

Purchases are processed by Paddle acting as merchant of record. Paddle handles billing, invoicing and any applicable sales tax or VAT, and its buyer terms apply to the transaction. We never see or store your card details.

We offer a 30-day money-back guarantee. If Pro is not right for you, for any reason, email support@userostra.com within 30 days of your purchase and we will refund you in full. You do not need to justify the request. Refunds are returned via the original payment method through Paddle. Once refunded, the associated licence stops being valid and Pro features return to the free version.

Price changes do not affect purchases already completed.

9. Ownership and intellectual property

The Software is owned by Splendid Edge Systems and is protected by copyright and other intellectual property laws. We retain all right, title and interest in and to the Software, including its code, engine, user interface, design, text-normalisation and prosody work, voice naming, icons and documentation, except for the components identified in clause 10.

"Rostra" and "Splendid Edge Systems" are our trademarks. This agreement grants you no right to use our names, logos or trademarks.

This agreement transfers no ownership. Any rights not expressly granted here are reserved.

10. Third-party and upstream components

The Software includes components owned by others, under their own licences. Those licences are not restricted by this agreement, and where they grant you rights, you have them. They include:

  • Portions derived from Orator (MIT), © 2024 Niranjan Akella
  • Kokoro TTS model weights and voice packs (Apache Licence 2.0)
  • misaki pronunciation lexicons (Apache Licence 2.0)
  • eSpeak NG (GNU General Public Licence v3.0), used as a separate command-line program, with a written offer of its corresponding source
  • ONNX Runtime and other bundled runtime dependencies, under permissive and weak-copyleft licences

The complete attributions and licence texts accompany the Software — on macOS in Rostra.app/Contents/Resources/Legal/, on Windows in the Licenses\ folder of the install directory.

11. Disclaimer of warranties

The Software is provided "as is" and "as available". We work hard to make it reliable, but to the extent permitted by law we do not warrant that it will be uninterrupted or error-free, that defects will be corrected, that it will be secure, or that the synthesised speech will be accurate, correctly pronounced, or suitable for any particular purpose. You are responsible for making your own backups of any audio you export.

If you are a consumer, this clause does not affect your statutory rights.

12. Limitation of liability

To the extent permitted by law:

  • we are not liable for any indirect, incidental, special, consequential or punitive damages, or for lost profits, lost revenue, or lost or corrupted data; and
  • our total aggregate liability arising out of or relating to the Software or this agreement will not exceed the amount you actually paid for the Software.

Nothing in this agreement excludes or limits liability that cannot lawfully be excluded or limited, including liability for death or personal injury caused by negligence, or for fraud. If you are a consumer, your statutory rights are unaffected.

13. Indemnification

You agree to indemnify and hold harmless Splendid Edge Systems and its proprietor against any claim, loss, liability and reasonable legal cost arising out of your use of the Software in breach of this agreement or in breach of any law, or arising out of the text you convert or the audio you produce.

This clause does not apply to the extent the claim arises from our own breach, negligence or wrongdoing, and if you are a consumer it applies only to the extent permitted by the law that applies to you.

14. Termination and perpetual fallback

This licence terminates automatically if you materially breach clause 4. On termination for breach, you must stop using the Software and delete all copies of it.

Perpetual fallback. Termination for any reason other than your breach — and any change to our products, pricing, terms, or availability — does not revoke your right to keep using the major version you lawfully purchased, on the terms under which you purchased it.

Clauses 2, 9, 10, 11, 12, 13, 15, 16 and 17 survive termination.

15. Export and sanctions

You confirm that you are not located in, and are not a national of or ordinarily resident in, a country subject to a comprehensive trade embargo, and that you are not on any restricted or denied-parties list. You agree not to use or transfer the Software in breach of any applicable export control or sanctions law.

16. Governing law and venue

This agreement is governed by the laws of Ghana, without regard to its conflict-of-laws rules. The courts of Ghana have jurisdiction over any dispute arising out of it.

If you are a consumer, this does not deprive you of the protection of the mandatory laws of your country of residence, and it does not remove any right you have to bring proceedings in the courts of that country.

17. General

  • Capacity. You must be at least 18, or the age of majority where you live, to accept this agreement.
  • Relationship to our other terms. This agreement governs your licence to use the Software. Our Terms of Use and Privacy Policy govern everything else, and together the three form the entire agreement between us. Where this agreement and the Terms of Use conflict on the scope of your software licence, this agreement controls; on all other matters the Terms of Use control.
  • Entire agreement. This agreement supersedes any prior agreement or understanding on its subject matter.
  • Severability. If any provision is held unenforceable, it is limited or severed to the minimum extent necessary and the rest remains in force.
  • No waiver. A failure to enforce any provision is not a waiver of it.
  • Assignment. You may not assign this agreement without our consent. We may assign it in connection with a merger, acquisition or sale of assets.
  • Changes. We may update this agreement; the date at the top shows when it last changed. Changes are not retroactive — the version you accepted when you purchased continues to govern that purchase.
  • Notices. We may communicate with you electronically, including by email to the address associated with your purchase.

Contact

Splendid Edge Systems
support@userostra.com
+233 55 997 0100 (Ghana) · +1 251 901 4675 (US)