Nova Chess Engine License Copyright (c) 2026 Nova Chess. All rights reserved. This license governs use of the Nova Chess engine, which includes the model weights (the "Model") and the accompanying source code (the "Code"), together the "Software," published at https://github.com/novachessai/novachess-engine and https://huggingface.co/novachess. By downloading, accessing, or using the Software, you agree to the terms below. If you do not agree, you may not use the Software. 1. PERMITTED USES Subject to the restrictions in Section 2 and the attribution requirement in Section 3, Nova Chess grants you a worldwide, royalty-free, non-exclusive license to do the following with the Software: (a) Run the Model on your own hardware for any personal, research, educational, or hobbyist purpose. (b) Copy, modify, and redistribute the Code, including inference servers, evaluation scripts, and wrappers. (c) Benchmark, compare, or analyze the Model against other models, and publish the results — including in peer-reviewed papers, blog posts, theses, and conference presentations, whether or not those venues charge for access. (d) Fine-tune the Model on your own data for personal, research, or educational use, subject to Section 4. (e) Operate a publicly playable bot that uses the Model on Lichess, Discord, Twitch, or similar platforms, including one whose operator accepts donations, tips, or sponsorships — so long as access to the bot itself is not gated by payment. (f) Use the Model as a demonstration or teaching tool in lessons, courses, workshops, or coaching sessions, including paid ones, provided the Model itself is not the product or service being sold. (g) Embed the Software in open-source projects that are not themselves commercial products. For clarity, a "commercial product" in (g) means software or services offered for sale, subscription, licensing revenue, or equivalent consideration. A free open-source project that accepts donations is not a commercial product. 2. RESTRICTED USES Without a separate commercial license from Nova Chess, you may not: (a) Sell, license, or sublicense the Model weights as part of a paid product, subscription, or service. (b) Offer a paid API, hosted inference endpoint, or similar service whose functionality depends on running the Model. (c) Include the Model or the Code in a commercial chess application, platform, game, analysis service, coaching service, training service, or competitive product. (d) Train, fine-tune, distill, or otherwise create a derivative model based on the Model, and then sell, license, sublicense, or offer paid access to that derivative model. See Section 4. (e) Use the Software to build, launch, or operate a service intended to compete directly with Nova Chess (www.novachess.ai), whether or not such a service charges users. (f) Remove, obscure, or modify the copyright notice, this license text, or the attribution required by Section 3. 3. ATTRIBUTION If you redistribute the Software, incorporate it in a public-facing project, or operate a public deployment (including bots under Section 1(e)), you must clearly credit Nova Chess and link to this project. A credit of the form: "Powered by Nova Chess — https://github.com/novachessai/novachess-engine" is sufficient. The credit must appear in a reasonably prominent location — for example, in the README of a redistributed repository, in the profile or about page of a deployed bot, or in the "about" section of a user-facing application. 4. FINE-TUNES AND DERIVATIVE MODELS A model obtained by fine-tuning, distilling, LoRA-adapting, merging, or otherwise deriving from the Model (a "Derivative Model") is itself subject to this license. In particular, you may fine-tune the Model and share the resulting weights for personal, research, or educational use, but you may not sell or offer paid access to a Derivative Model without a separate commercial license from Nova Chess. This clause does not cover models that are trained independently from scratch without using the Model's weights as a starting point, even if such models are trained on data the Model also saw. 5. MODEL OUTPUTS Outputs produced by running the Model — including predicted moves, complete games, evaluations, probability distributions, and any textual or numeric data derived from inference — are not subject to the restrictions in Section 2. You may use, publish, and distribute Model outputs freely for any purpose, commercial or otherwise. 6. COMMERCIAL LICENSING Commercial licenses that grant rights beyond those in Section 1 are available from Nova Chess. For inquiries, contact support@novachess.ai. 7. TERMINATION If you breach any term of this license, your rights under Section 1 terminate automatically. Your rights are reinstated if you cure the breach within thirty (30) days of becoming aware of it, provided Nova Chess has not already notified you in writing of the breach. Sections 3, 5, 8, 9, and 10 survive termination. 8. NO WARRANTY THE SOFTWARE IS PROVIDED "AS IS," WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NONINFRINGEMENT. THE MODEL IS A STATISTICAL PREDICTOR AND MAKES NO GUARANTEE OF CORRECTNESS, LEGALITY, OR SUITABILITY FOR ANY PARTICULAR USE. 9. LIMITATION OF LIABILITY TO THE MAXIMUM EXTENT PERMITTED BY LAW, IN NO EVENT SHALL NOVA CHESS, ITS CONTRIBUTORS, OR ANYONE ASSOCIATED WITH THE SOFTWARE BE LIABLE FOR ANY CLAIM, DAMAGES, OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT, OR OTHERWISE, ARISING FROM, OUT OF, OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 10. GOVERNING LAW This license is governed by the laws of the Commonwealth of Massachusetts, United States, without regard to conflict-of-law principles. Any dispute arising out of or relating to this license shall be brought exclusively in the state or federal courts located in Massachusetts, and you consent to the personal jurisdiction of those courts. 11. ENTIRE AGREEMENT This license is the entire agreement between you and Nova Chess regarding the Software and supersedes any prior communications, understandings, or agreements on the subject. --- Questions about this license or commercial use: support@novachess.ai