Privacy policy.

Information We Collect

Sincere stores the following:

• Workspace installation data from Slack's OAuth flow (team ID, bot tokens) — needed to post messages into your workspace
• The text of messages submitted via /sincere, together with their agree/disagree totals — stored without any link to the author
• Hashed (HMAC) tokens used to enforce one vote per message, one post per day, and content-moderation limits

Your Slack user ID is processed in memory when you interact with the bot, but it is never written to the database in raw form.

How We Use Your Information

We use your information to:

• Provide and Maintain the Application: We use your information to deliver the functionality of our application and ensure it operates smoothly.
• Enforce the Rules: The hashed tokens exist only to enforce one vote per message and one post per day.
• Keep Feedback Safe: Every message is automatically screened before posting, so honest criticism gets through while harassment, threats, and doxxing do not. Rejected messages are not stored.
• Respond to Your Inquiries: We use your information to respond to your questions, requests, and support inquiries.

Sincere is built so that it cannot tie a post or a vote to the person behind it. That link is never stored, so we could not reveal it later even if asked. If misuse ever forces us to change this design, we will update this policy and the anonymity page before any change takes effect; a change can never apply retroactively to messages already posted.

Data Security

We implement appropriate technical and organizational measures to protect your information from unauthorized access, disclosure, alteration, or destruction. However, please note that no method of transmission over the internet is completely secure.

Third-Party Services

Sincere runs on Slack. What Slack itself collects — including the fact that you used a slash command — is governed by Slack's own privacy policy, which we cannot change.

For content moderation, the text of a submitted message is screened using Anthropic's Claude API before it is posted. Only the message text is sent — never your name, user ID, workspace, or any other identifier — and under Anthropic's commercial terms, API data is not used to train their models. We store nothing from that exchange: neither rejected messages nor moderation verdicts are kept.

We do not share your information with any other third party, and we do not sell data to anyone.

Your Rights

You have the right to:

• Request the deletion of information that can be tied to your Slack workspace and/or any users belonging to said workspace.

One consequence of the anonymity design: because posts are not linked to the people who wrote them, we cannot selectively delete your posts. A workspace admin can request deletion of all data belonging to the workspace.

Contact Us

If you have any questions or concerns about this Privacy Policy, please contact us at:

lambdazero.office@proton.me

Changes to This Privacy Policy

We may update this Privacy Policy from time to time. We will notify you of any significant changes by posting the updated policy on our website.