Terms of Service

You may need to create an account to use certain features. You are responsible for maintaining the confidentiality of your account credentials and for all activity that occurs under your account. Email verification is required before you can sign in.

You agree to provide accurate information when creating your account and to update it as necessary. You agree not to share your account, impersonate another user, or create accounts to evade enforcement actions taken against an existing account.

The Service is not directed at children under 13. Do not create an account if you are under 13. See the Privacy Policy §11 for parental contact information.

You retain ownership of the challenges, submissions, Proof Cards, comments, and other content you provide to BuildLeague. By providing content, you grant BuildLeague a non-exclusive, worldwide, royalty-free license to display, distribute, index, reformat, cache, and promote your content within and in connection with the Service, including in social previews, match standings, and search results.

Following account deletion, your contributions may be retained on the platform in anonymized or de-authored form so that challenge outcomes and matches other teams participated in remain intact. See the Privacy Policy §9 for what this looks like in practice.

You agree not to post content that:

• Violates any applicable laws or regulations
• Infringes the intellectual property rights of others
• Contains malicious code, malware, spam, or deceptive content
• Harasses, threatens, defames, or incites violence against others
• Contains the private or sensitive personal information of others
• Contains sexual content involving minors
• Contains operational secrets (API keys, private keys, passwords) — note that we automatically redact many such patterns before storage, but you remain responsible for what you share

The verified production outcomes and evidence in your Proof Cards originate from your own systems. BuildLeague does not control or take responsibility for the accuracy, completeness, or reliability of the outcomes you submit, and enterprise teams should perform their own diligence before acting on them.

You are responsible for ensuring you have the right to submit and share any outcomes or submission content you provide, including compliance with your own users' privacy expectations and any agreements you are bound by.

The hosted Service, the BuildLeague name, the BuildLeague logo, the visual design, and the branding are owned by BuildLeague. All rights are reserved. Nothing in these Terms grants you any right to use the BuildLeague name, logo, or branding in your own products or services without prior written permission.

Source-visible, not open source. The BuildLeague source code is published in a public repository so that anyone can read it and verify the security and privacy claims made on the Data Security page. The source code is governed by the LICENSE file in that repository, which reserves all rights and grants no license to copy, modify, distribute, host, or offer a derivative service. Reading the source for personal study and conducting good-faith security research against your own local instance are expressly permitted by the LICENSE.

You may not reverse-engineer the hosted Service, decompile or extract proprietary algorithms from it, or use the Service to train a competing AI model or competing platform. The good-faith security-research carve-out in the next section overrides this restriction within its stated scope.

You agree not to:

• Scrape, crawl, or extract content from the Service except via documented APIs and in accordance with their published rate limits
• Access the Service through automated means (bots, scripts, headless browsers) for purposes other than your own personal use, security research permitted under section 11, or use of the documented APIs
• Interfere with, disrupt, or impose an unreasonable load on the Service or the infrastructure that supports it
• Attempt to bypass authentication, authorization, rate limiting, or any other security control
• Use the Service to send unsolicited messages, advertise, or promote external products in violation of platform rules
• Use the Service to train an AI model or build a derivative dataset without our express written permission

If you believe content on BuildLeague infringes your copyright, you may submit a takedown notice to the operator of this instance. Your notice should include:

• A description of the copyrighted work you claim has been infringed and a URL or identifier for the original work
• The URL of the BuildLeague challenge, submission, comment, or other item you want removed
• Your full legal name, postal address, telephone number, and email address
• A statement that you have a good-faith belief that the use is not authorized by the copyright owner, its agent, or the law
• A statement, made under penalty of perjury, that the information in your notice is accurate and that you are the copyright owner or authorized to act on the owner's behalf
• Your physical or electronic signature

Submit takedown notices through the operator contact channel listed on the About page or by opening an issue in our GitHub repository marked "DMCA". We may forward the contents of your notice (including your contact information) to the user who posted the content. We may terminate the accounts of users who repeatedly infringe. If your content is removed and you believe the removal is mistaken, you may submit a counter-notice through the same channel.