What we collect — and why
To cast your chart, 14 Main Stars uses the birth details you enter: name, gender, birth date, birth time, and birth city. We use those inputs to compute the Zi Wei Dou Shu and BaZi reading you request. If you sign in or use a save, purchase, invite, or account feature, the related information is also processed to provide and secure that feature.
Signing in
You can sign in with Apple or Google. We receive the account identifier and profile details that provider makes available, such as a name or email, to create and identify your account and sync saved charts. Signing in does not subscribe you to marketing emails. You can also cast a guest chart without creating an account.
Your charts are saved to your account
When you are signed in, charts may be stored with your account so you can revisit them without re-entering the inputs. Account access controls are intended to keep saved readings available to that account. Our hosting, authentication and database providers process the data needed to operate those features. Some guest and share flows place birth inputs in the result URL, so keep result and invite links private.
Service providers
Google Firebase supports authentication and database storage; Vercel supports hosting and product analytics. Apple, Stripe and supported local payment rails process purchases, while Google AdMob serves the optional app ads described below. These providers receive the account, transaction, network, device or usage data needed to deliver their part of the service, under their own privacy terms.
Purchases
Purchases in the iOS app are handled by Apple through the App Store; we receive only a confirmation and the entitlement it grants — your payment details never touch our servers. On the website, payment is handled by Stripe (and local rails such as FPX / e-wallets); your card details go directly to the processor, not to us.
Advertising in the app
The website shows no ads. In the iOS app, you may choose to watch a short rewarded video to unlock a free reading — you can always buy the reading instead and never see an ad. These ads are served by Google AdMob. AdMob may collect device identifiers, coarse location (derived from your IP address), and ad-interaction data in order to deliver the ad and prevent fraud. We request non-personalized ads only: the ads are contextual, are not linked to your identity, and are notused to track you across other apps or websites — so the app does not ask for tracking permission. Google's handling of this data is governed by the Google Privacy Policy.
Analytics
We collect minimal usage and conversion statistics to improve the product. For requests handled by our hosting platform, our server reduces technical request data to an ISO country code, first-level region code and coarse device class (mobile, tablet, desktop or unknown). Our first-party event and session records do not retain the raw IP address, city, precise coordinates or raw User-Agent. Advertising click identifiers such as gclid, gbraid, wbraid and msclkid are reduced to a yes/no paid-click signal and the identifiers are not retained. One-way hashed, pseudonymous session and account keys let us join a successful provider-confirmed purchase for aggregate conversion and revenue reporting by country, device class, landing page and language. Event properties are designed not to include raw email or birth details. Analytics, hosting, payment and crash providers can still receive ordinary network, device, browser, transaction and performance data when they deliver their services.
Deleting your data
Want your account and saved charts deleted? You can delete your account from within the app (Account → Delete account), or email us at the address below and we will remove everything.
Using our chart calculator inside an AI assistant
We publish a free, public chart endpoint so an AI assistant — such as our official ChatGPT assistant — can cast a chart for you inside that conversation. When you use it, the birth details you gave the assistant are sent to our server to compute the chart, and we send back the calculated result. We do not store anything from those requests: no account, no saved chart, no birth data is written to our database. We keep only an anonymous count of how many charts were cast through this route, with the language used — never your birth details. The assistant itself is operated by that AI provider under their own privacy policy, so what they retain of your conversation is governed by them, not by us.
Sharing is under your control
If you choose to use the share feature, the app creates an image and hands it to your device's standard share sheet. What you do with that image — and whom you share it with — is entirely your choice and is governed by the privacy policy of whichever app or service you select.
Children's privacy
14 Main Stars is not directed at children, and we do not knowingly collect personal information from children.
Changes to this policy
If we change how 14 Main Stars handles information, we will update this page and revise the "Last updated" date above.
Contact
Questions about this policy? Email support@14mainstars.com.