Privacy Policy

Last updated: October 13, 2026

This Privacy Policy explains what information Mermaid World (“we”, “us”) collects when you use the Mermaid World app and related services (the “Service”), how we use it, and the choices you have.

We collect what we need to run the Service: your sign-in details, your profile, and your conversations.
Your messages are sent to AI model providers so the characters can reply.
We don’t sell your personal information, show ads, or use third-party analytics or advertising trackers.
You can delete your account and conversations at any time in the app.

1. Information we collect

Account information

Guest accounts. When you first open the app, we create a guest account. So that your device gets the same guest account back, we store a one-way hash of the app’s device identifier (Apple’s identifier for vendor), not the identifier itself.
Email sign-in. Your email address.
Sign in with Google. Your Google account ID, email address, first name, and profile picture link.
Sign in with Apple. Your Apple account ID, the email address Apple shares with us (which may be a private relay address, or none), and your first name if you choose to share it.

Profile information

The nickname, introduction, pronouns, and picture on your profile, and the personas you write to tell characters who you are.

Conversations

The messages you send, the characters’ replies, and information derived from them that keeps conversations consistent, such as summaries and what a character remembers about your chat. We also keep your settings, such as which AI model characters reply with.

Technical information

When you sign in or your session is renewed, we record your IP address and your device’s user agent with that session. Our servers keep request logs, which can include IP addresses, for security and troubleshooting. We also record each use of an AI model (the account, the model, and how much it was used) to track costs and prevent abuse.

What we don’t collect

The app does not access your contacts, photos, microphone, or precise location. We don’t use third-party analytics or advertising tools, and we don’t track you across other companies’ apps or websites.

2. How we use information

To provide the Service: create and keep your account, generate characters’ replies, keep conversations consistent, and show your profile.
To sign you in: email you one-time sign-in codes, and check Google and Apple sign-ins.
To keep the Service safe: prevent abuse and fraud, apply usage limits, enforce our Terms of Use, and protect accounts.
To fix problems and improve how the Service works.
To comply with the law.

We do not use your conversations to train AI models.

3. AI model providers

To generate a reply, we send your message to a third-party AI model provider together with the context the reply needs: the character, the recent conversation, conversation summaries, and the nickname and persona you use in that chat. Today these providers are Anthropic and DeepSeek; which one handles a reply depends on the model selected. They process this data to produce the reply, under their own terms and privacy policies, and may process it in other countries, including the United States and China.

4. How we share information

We share information only:

with service providers that help us run the Service: the AI model providers above, our cloud hosting provider (Zeabur), our email delivery provider (Resend), and Google or Apple when you choose to sign in with them;
when the law requires it, or to protect the rights, safety, and security of our users, the public, or Mermaid World;
as part of a merger, acquisition, or sale of assets, in which case this policy continues to apply to your information.

We do not sell your personal information, and we do not share it for targeted (cross-context behavioral) advertising.

5. How long we keep information

We keep your account, profile, personas, and conversations for as long as your account exists.
Deleting a chat in the app removes it from your chats; we keep it on our servers until you delete your account.
When you delete your account, we immediately and permanently delete your account, profile, personas, conversations, sign-in connections, and sessions. If you signed in with Apple, we also revoke Mermaid World’s access to your Apple ID. We keep records of AI model use (an account ID, the model, and how much it was used, with no message content) for accounting and abuse prevention.
Sign-in codes expire after 10 minutes. Server logs and backups are kept for a limited time and then overwritten.

6. Your choices and rights

Edit your profile and personas in the app at any time.
Delete your account in the app under Me › Settings › Delete account.
Depending on where you live, including California and other US states, you may have the right to know what personal information we hold about you, to get a copy of it, to correct it, and to have it deleted. To make a request, email us at wohoodev@gmail.com. We may ask you to confirm the request from the email or sign-in on your account. We will not treat you differently for exercising these rights.

7. Children

The Service is only for people 18 and older. We do not knowingly collect personal information from anyone under 18. If you believe someone under 18 is using the Service, contact us and we will delete the account.

8. Security

We use reasonable measures to protect your information, including encrypted connections, keeping your sign-in tokens in your device’s Keychain, and storing only hashes of session tokens on our servers. No system is completely secure, so we cannot guarantee the security of your information.

9. International transfers

Our servers and service providers may be located in countries other than yours. By using the Service, you understand that your information may be transferred to and processed in those countries.

10. Changes to this policy

We may update this policy. If a change is material, we will let you know in the app or by other reasonable means. The date at the top shows when it was last updated.

11. Contact

If you have questions about this policy or your information, email us at wohoodev@gmail.com.