CE PRO

Privacy Policy

Effective date: September 12, 2026 · Applies to the CE PRO mobile app and ce.thanlar.com

CE PRO ("the app") is an offline-first civil engineering toolkit developed by Thanlar. This policy explains what information the app processes, why, and the choices you have. CE PRO is offline-first and can be used as a guest. Creating an account is optional. We do not sell personal information or use it for advertising.

1. Summary

  • Your calculations, projects and site records are stored on your device.
  • If you choose to sign in, Firebase Authentication processes your account identity.
  • We use a pseudonymous device identifier generated on your device — not your name, email or phone number.
  • We collect minimal usage events (which tool was used) to keep the app working and prevent abuse.
  • Messages and images you send to the AI Assistant are processed through our server and a third-party AI provider.
  • We do not sell or share your data for advertising.

2. Optional accounts and sign-in

You may sign in with Google or Apple. We use Firebase Authentication, a Google service, to create and maintain the account. Depending on the provider and the information you choose to share, this may include a provider identifier, display name, email address, profile image URL, and authentication tokens needed to keep you signed in. Apple may provide a private relay email address; we treat it as an ordinary email address.

Google and Apple authenticate you under their own terms and privacy policies. CE PRO does not receive your Google or Apple password. We use account information only to provide sign-in, account management, security, and account deletion.

3. Information stored on your device

The app stores locally on your device: calculations and results, projects, daily reports, pour logs, material issues, level books, preferences, language settings and cached data used for offline operation. This information stays on your device unless you choose to sync, and you can remove it by clearing the app's data or uninstalling the app.

4. Device identifier

On first launch the app generates a cryptographic key pair (Ed25519) on your device. A device identifier is derived from the public key. This identifier is pseudonymous: it is a random-looking string such as ce_dev_… that is not connected to your name, email, phone number or contacts. It is used to:

  • enforce app version policy and feature availability;
  • prevent abuse (request throttling, blocked devices);
  • keep the AI gateway secure (signed requests and replay protection).

Reinstalling the app creates a new identifier, and the previous one is no longer associated with your device.

5. Usage events

The app sends lightweight usage events (for example, which tool was opened and a coarse result category) tied to the pseudonymous device identifier. These are used to prioritise fixes, improve tools and detect abuse. Usage events do not contain the values you calculate or your personal details.

6. AI Assistant

When you use the Civil Engineering AI feature, the text you type and any image you attach (JPEG, PNG or WebP, up to 3 MB) are transmitted over an encrypted connection to our Cloudflare Worker gateway, which forwards the request to a third-party AI provider (OpenRouter, acting as the router to the underlying AI model) to generate a response.

  • Your requests are signed with the key generated on your device; our server never receives identifying personal information from the app.
  • Our gateway applies abuse throttles and security logging (device identifier, request characteristics) to protect the service.
  • AI responses are preliminary guidance only and are not a substitute for a qualified engineer or the locally adopted code.
  • Please do not include personal or confidential information in AI prompts. Redact drawings and photos before sending them.

7. IP addresses and security data

When the app contacts our servers (AI gateway, remote configuration, sync), our hosting provider processes your IP address. We apply IP- and device-based rate limits and keep short-lived security audit records to detect and prevent abuse. These records are not used for advertising or profiling.

8. Remote configuration and updates

The app fetches a small remote configuration (feature access, minimum supported version) from our servers so we can block broken or insecure builds and manage features. This configuration is tied to the pseudonymous device identifier and app version, not to your identity.

9. What we do not do

  • We do not require an account to use the core offline tools.
  • We do not include advertising SDKs or third-party analytics trackers.
  • We do not sell or rent your information.
  • We do not access your photos, contacts or files except an image you explicitly attach in the AI Assistant.

10. Third-party services

  • Firebase Authentication — provides optional account sign-in and account management.
  • Google and Apple — authenticate users who choose their respective sign-in option.
  • Cloudflare — hosts our API gateway, sync services and this website, and processes request metadata (including IP address) as part of providing that infrastructure.
  • OpenRouter / AI model providers — process AI Assistant prompts and attachments to generate responses, under their own terms and privacy policies.
  • Google Play — handles app distribution and updates on Android.

11. Data retention and deletion

On-device data remains until you delete the app or clear its data. Server-side usage and security records are retained only as long as needed for the purposes above, then deleted or aggregated.

You can permanently delete an optional CE PRO account in the app at Profile → Account Settings → Delete Account. This deletes the Firebase Authentication account and CE PRO data stored for the account on the device, including the local profile, saved projects, favourites, and AI chat history. For Apple accounts, CE PRO requests a fresh authorization and revokes the Apple authorization as part of deletion. Deletion cannot be undone. You may also contact admin@thanlar.com about data associated with a device identifier.

12. Children

CE PRO is a professional tool and is not directed at children under 13.

13. Security

All traffic to our servers uses encrypted connections, and protected endpoints are signed with the key pair generated on your device. No system is perfectly secure, but we limit what we collect so there is little to expose.

14. Changes to this policy

We may update this policy as the app evolves. Material changes will be reflected in the app or on this page with a new effective date.

15. Contact

Questions about this policy: admin@thanlar.com