Privacy Policy

1. Who we are

ChainSources is an educational blockchain and Web3 resource published by HZ Technologies ("ChainSources", "we", "us"). It explains Bitcoin, Ethereum, DeFi, Layer 2 networks and related technology from first principles, and presents a curated feed of articles from reputable publishers. HZ Technologies is the controller responsible for the limited information described in this policy. This policy applies to:

• the ChainSources website at chainsources.net;
• the ChainSources Android app (net.chainsources.app);
• the ChainSources iOS app (com.hztechnologies.chainsources);
• the ChainSources content and market-data API at chainsources.net/api/ that the website and apps use.

2. Information we collect

2.1 Information you give us

ChainSources has no account system, no sign-up, no login, no contact form, no newsletter and no payments. We never ask for your name, phone number, postal address, date of birth, payment details, government ID, wallet address, private keys or seed phrase, and there is no ChainSources user database. The only exception is an email you choose to send us — see section 4.

2.2 Information collected automatically

ChainSources itself does not collect usage information about you. Specifically, the website and apps do not include:

• analytics or product-measurement tools (no Google Analytics, Firebase Analytics, or similar);
• advertising, ad networks or advertising identifiers;
• cross-app or cross-site tracking of any kind, fingerprinting, or session recording;
• social media tracking pixels;
• crash-reporting or telemetry SDKs;
• access to your location, camera, microphone, contacts, photos, calendar or health data.

Neither app asks for any device permission beyond ordinary internet access.

3. Network requests and third-party services

Although we collect nothing about you, using ChainSources involves normal internet requests. As with any website or app, the servers that answer those requests can see technical connection details such as your IP address, the time of the request and your browser or device user-agent string. This is inherent to how the internet works; ChainSources does not use these details to identify you or build a profile.

3.1 The ChainSources API

The website and both apps request public content from two endpoints:

• https://chainsources.net/api/feed — the current list of verified educational articles;
• https://chainsources.net/api/market — current public market figures (for example Bitcoin price history and supply) shown alongside the educational material.

These requests carry no identifier, no account and no personal information. The market figures are gathered by our own servers from public data providers on a schedule; your device never contacts those providers, and they receive no information about you.

3.2 Third-party services

Service	Used by	Purpose	What it can see
Cloudflare	Website, both apps, email	Hosting, CDN, security, email forwarding	IP address, request metadata
Google Fonts	Website only	Typefaces (DM Sans, Space Mono)	IP address, user-agent
Tailwind CDN	Website only	Stylesheet delivery	IP address, user-agent
Google Play / Apple App Store	App downloads	App distribution	Governed by your store account

Cloudflare hosts chainsources.net and serves the API. As our hosting and security provider it processes requests on our behalf and may retain short-term logs, including IP addresses, to deliver the service and protect against abuse. See the Cloudflare Privacy Policy.

The website loads fonts and a stylesheet from Google and the Tailwind CDN. Those providers receive your IP address as a normal part of serving those files. See the Google Privacy Policy. The Android and iOS apps do not load these third-party resources — their interface is built in, so the only host they contact is chainsources.net.

When you download an app, Google Play or the Apple App Store processes that transaction under their own privacy policies. They may provide us with aggregated, non-identifying statistics (such as install counts); we do not receive your store account details.

4. When you contact us

If you email support@chainsources.net, we receive your email address, the contents of your message and any attachments you choose to include. Messages to that address are forwarded by Cloudflare Email Routing to a mailbox operated by HZ Technologies (hosted by Google). We use this information only to read and reply to your message. We never add you to a mailing list and never share your message with anyone else, except where required by law.

5. How we use information

The limited information described above is used only to:

• deliver the website, apps and API content you request;
• keep the service secure and protect it against abuse (performed by Cloudflare);
• respond to support emails you send us;
• comply with legal obligations.

We do not use information for advertising, profiling, automated decision-making or selling.

6. Legal bases for processing (EEA and UK visitors)

Where the GDPR or UK GDPR applies, we rely on:

• Legitimate interests — to serve and secure the website, apps and API (technical request data processed by Cloudflare) and to answer questions you send us;
• Legal obligation — where we must keep or disclose information by law.

Because we do not use cookies or tracking technologies that require consent, there is no consent banner.

7. Cookies and on-device storage

ChainSources sets no cookies on the website or in either app, and uses no cookie-based tracking.

Some information is stored locally on your own device so the products work well, including offline. It stays on your device, is never sent to us, and is removed when you clear the app's data, uninstall the app, or clear your browser storage:

• iOS app — your appearance (light/dark) preference and reading progress are stored in UserDefaults; the most recent verified article list and market-data snapshot are cached in the app's Caches directory so the app can still show real, previously verified content when you are offline.
• Android app — the educational content is bundled inside the app. The app's WebView keeps a local copy of the most recent article list and market-data snapshot for offline use.
• Website — your browser may cache pages and the article list according to normal HTTP caching rules. The site writes no cookies and stores no identifiers in your browser.

Because we do not track you, we have nothing to change in response to "Do Not Track" or Global Privacy Control signals — the result is the same either way.

8. Links to other websites

ChainSources curates headlines, short excerpts and links from reputable blockchain and Web3 publishers — for example the Ethereum Foundation, Bitcoin Core, Chainalysis, CoinDesk and Trail of Bits. Every article is clearly attributed to its original publisher.

When you open an article, you leave ChainSources and go to that publisher's own website, which has its own privacy policy and may use cookies, analytics and advertising that we neither control nor see. We are not responsible for the content or privacy practices of those sites.

9. Sharing and selling of data

We do not sell, rent or trade personal information, and we do not share it for cross-context behavioural advertising. We would disclose information only to the service providers named in this policy, acting on our behalf, or where required by law, a valid legal request, or to protect the rights and safety of ChainSources and its users.

10. Data retention

• Support emails — kept only as long as needed to resolve your request and handle any follow-up, then deleted. You can ask us to delete your correspondence at any time.
• Technical request logs — retained by Cloudflare for short periods under its own policies. ChainSources keeps no request logs that identify you.
• On-device data — stays on your device until you clear it or uninstall the app.

11. International transfers

Our service providers, including Cloudflare and Google, operate globally, so technical request data or support emails may be processed in countries other than your own, including the United States. These providers use recognised safeguards, such as the European Commission's Standard Contractual Clauses, for such transfers.

12. Security

All ChainSources traffic is served over HTTPS. Because we operate no account system and store no personal data on our servers, there is no ChainSources user database that could be breached. On-device data is protected by your operating system's standard security model. No method of transmission over the internet is completely secure, but we keep the data we handle to the minimum possible.

13. Children's privacy

ChainSources is a general-audience educational resource and is not directed at children under 13 (or the minimum age required in your country). We do not knowingly collect personal information from children. If you believe a child has sent us personal information by email, please contact us and we will delete it.

14. Your rights

Depending on where you live, laws such as the GDPR, UK GDPR and the California Consumer Privacy Act (CCPA/CPRA) give you rights to access, correct, delete or export your personal data, to object to or restrict its processing, and not to be discriminated against for exercising these rights.

Because ChainSources holds no personal data about you, in most cases there is nothing for us to retrieve, amend or delete. If you have emailed us, you can ask for a copy or deletion of that correspondence by writing to the address below; we will respond within 30 days. You can remove all locally stored data at any time by clearing your browser storage or uninstalling the app. You also have the right to complain to your local data protection authority.

15. Educational content and crypto wallets

ChainSources is for education only. We will never ask for your private keys, seed phrase, wallet passwords or funds, and neither the website nor the apps connect to your crypto wallet. Anyone claiming to be ChainSources and asking for such information is not us — please report it to support@chainsources.net. Nothing on ChainSources is financial or investment advice.

16. Changes to this policy

If ChainSources changes in a way that affects this policy, we will update this page and change the "Last updated" date at the top. Material changes will be reflected here before or when they take effect.

17. Contact

You can also visit the ChainSources support page or read our Terms of Use.