SigmaChat Terms of Service
Effective August 9, 2026
1. The agreement
These terms are an agreement between you and SigmaChat ("SigmaChat," "we," "us"). They cover the SigmaChat app at sigmachat.org, the website and blog, the public report form, and the API. The Community Guidelines and the Privacy Policy are part of these terms. By creating an account or using SigmaChat, you accept all three. If you do not accept them, do not use SigmaChat.
2. Your account
You must be at least 13 to use SigmaChat, or older where your local law sets a higher age for services like this.
Give accurate information when you sign up, keep your password to yourself, and tell us if you think your account has been compromised. You can add two-factor sign-in in Settings, and we recommend it. What happens on your account is your responsibility. Automated accounts are allowed only through the API as registered apps.
3. The service
SigmaChat is free of charge. If we ever introduce paid features, we will say so clearly and get your agreement to separate terms before anything costs money.
Features will change over time, and we may add, modify, or retire them. We do not promise the service will always be available or that content will be preserved indefinitely. The export tool in Settings gives you a copy of your data whenever you want one.
4. Your content
What you post is yours. You give us a non-exclusive, worldwide, royalty-free license to host, store, reproduce, adapt, and transmit your content, only as needed to operate SigmaChat. That includes making thumbnails and transcodes, generating link previews, delivering messages to the people and boards you address, running the screening described in the Privacy Policy, and passing board content to apps that the board's admins installed. We may exercise this license through the providers listed in the Privacy Policy. The license ends when you delete the content or your account, apart from the retention windows in the Privacy Policy and copies already delivered to recipients or to installed apps.
You are responsible for your content, and by posting it you confirm you have the rights to post it.
5. Boards, admins, and DMs
Whoever creates a board is its first admin. Admins control the board's membership, invites, roles, settings, and whether text screening is on, and they can transfer ownership. Their decisions inside a board are their own; we are not a party to disputes between members and admins. Admins have no access to anyone's DMs, and one-on-one DMs have no admin at all.
We can act on any board or any content when these terms, the Guidelines, or the law requires it.
6. Rules
The Community Guidelines describe expected conduct in full. The floor, everywhere on SigmaChat:
- Nothing illegal. Sexual content involving minors, in any form, means immediate termination and referral to authorities where the law requires it.
- No posting intimate images of a person without their consent, whether authentic or computer-generated.
- No threats, stalking, harassment, or incitement of harm.
- No malware, phishing, or deceptive links.
- No spam or artificial manipulation of the platform, including fake accounts and mass unsolicited invites.
- No scraping or automated access outside the API.
- No probing or attacking the service's security. If you find a vulnerability, report it to us instead of testing it against other people's data.
- No impersonating people, boards, or SigmaChat itself.
- No evading enforcement, including returning on a new account after a ban.
- No knowingly false reports.
7. Screening, enforcement, and appeals
Automated screening works as the Privacy Policy describes. We do not review everything posted and have no obligation to, and we may remove or refuse content that violates these terms or the law.
Platform enforcement runs on a ladder: a warning on your account's record, then a temporary suspension during which you can read but not post, react, invite, or create, then a ban. Severe violations skip the ladder. Board admins have their own tools, and a board-level action is separate from a platform-level one.
Enforcement actions come with an email notice. To contest one, reply to that notice or write to legal@sigmachat.org and we will review it. Deleting your account does not lift a ban.
8. Intimate images
Anyone can report a nonconsensual intimate image at sigmachat.org/report, with or without an account, on their own behalf or as an authorized representative of the person depicted. On a valid report we remove the content within 48 hours, as the federal Take It Down Act requires, and we fingerprint the file to block identical copies from being uploaded again. We act on these reports in good faith and may remove reported content on that basis even where its legality is unclear. Knowingly false reports violate these terms and may violate the law.
9. Copyright
We respond to copyright notices under the DMCA. To file one, send the following to copyright@sigmachat.org: identification of the copyrighted work, the location of the material on SigmaChat, your contact information, a statement that you believe in good faith the use is unauthorized, a statement under penalty of perjury that the notice is accurate and you are authorized to act for the owner, and your physical or electronic signature.
If your content is removed on a notice you believe is mistaken, you can send a counter-notice with the corresponding statutory elements, and we will restore the material in 10 to 14 business days unless the claimant files a court action. Accounts that repeatedly infringe are terminated. Knowingly misrepresenting a claim or counter-claim carries liability under 17 U.S.C. § 512(f).
10. Apps, bots, and the API
Board admins can install third-party apps and webhooks. Installed apps receive events from that board, including message text, as the Privacy Policy describes, and the developer is responsible for what happens after delivery. We can suspend or remove any app.
If you build on the API: register your app, keep its tokens secret, and use data received from a board only to operate your app for that board. Delete that data when your app is uninstalled or when we or the board asks. Do not sell it or use it for advertising. Respect the rate limits. We may change the API or revoke access, and your app and its obligations to its own users are yours.
11. SigmaChat's property
The SigmaChat software, design, and name belong to us. We give you a limited license to use the app as intended by these terms. Do not copy, resell, or misrepresent the origin of the service. Feedback you send us can be used without obligation to you.
12. Termination
You can delete your account at any time in Settings, under Data. We can suspend or terminate accounts for violating these terms, when the law requires it, or to protect the service and the people on it, using the ladder in section 7 where reasonable. If we ever shut SigmaChat down, we will give you notice and time to export your data.
Sections 4 (for the retention windows), 8, 9, and 13 through 16 survive termination.
13. Disclaimers
SigmaChat is provided as is and as available, without warranties of any kind, express or implied, including merchantability, fitness for a particular purpose, and non-infringement. Content posted by users is theirs, not ours. We do not warrant that the service will be uninterrupted or error-free. Some jurisdictions limit these disclaimers, and they apply to the fullest extent the law permits.
14. Limits on liability
To the fullest extent the law permits, we are not liable for indirect, incidental, special, consequential, or punitive damages, or for lost data, profits, or goodwill, arising out of the service or these terms. Our total liability for all claims is capped at the greater of $100 or the amount you paid us in the 12 months before the claim, which for a free service is $100. Nothing in these terms limits liability that cannot be limited by law, and if you live somewhere with mandatory consumer protections, those protections still apply.
15. Indemnity
If a third party brings a claim against us because of your content or your violation of these terms, you will cover the resulting costs and damages, and we will let you know about the claim promptly.
16. Disputes
If something goes wrong, email legal@sigmachat.org first and give us 30 days to work it out with you. These terms are governed by the law of Hawaiʻi, excluding its conflict-of-law rules, and disputes belong in the state or federal courts located in Hawaiʻi, where both of us consent to venue. You can always bring a qualifying claim in small claims court where you live. If you are a consumer in the EEA or UK, you keep the protections and court access your local law gives you.
17. Changes to these terms
We can update these terms. For material changes we will give notice in the app or by email before they take effect, and using SigmaChat after that date means you accept them. If you do not, stop using the service and delete your account.
18. General
These terms, the Community Guidelines, and the Privacy Policy are the whole agreement between us about SigmaChat. If part of these terms is unenforceable, the rest stands. Not enforcing a provision is not a waiver of it. You may not assign this agreement; we may assign it in a merger, acquisition, or sale of the service, and section 5 of the Privacy Policy's business-transfer terms apply to your data if that happens.