Privacy Policy

1. Who we are

ChainSources is an educational blockchain and Web3 resource published by HZ Technologies. It covers Bitcoin, Ethereum, DeFi and related technology from first principles. This policy applies to:

• the ChainSources website at chainsources.net;
• the ChainSources Android app (net.chainsources.app);
• the ChainSources iOS app (com.hztechnologies.chainsources).

2. Personal information we collect

None. Across all three products there is no account system, no sign-up, no login, no contact form and no newsletter. We do not ask for your name, email address, phone number, postal address, date of birth or payment details, and there is no ChainSources user database.

Specifically, ChainSources does not include:

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

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

3. Network requests

Although we collect nothing about you, using ChainSources does involve 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, not something ChainSources records for its own purposes.

3.1 The ChainSources Content API

The website and both apps request the verified article list from https://chainsources.net/api/feed. That request carries no identifier, no account and no personal information — it simply asks for the current public article list. We do not log it to build any profile of you.

3.2 Third-party services used

Service	Used by	Purpose	What it can see
Cloudflare	Website, both apps	Hosting, CDN, security	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

Cloudflare hosts chainsources.net and serves the content 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. 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.

4. Links to third-party websites

ChainSources aggregates 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.

5. Cookies and on-device storage

ChainSources sets no cookies of its own, on the website or in either app. We use no cookie-based tracking, so there is no cookie consent banner to dismiss.

Some information is stored locally on your own device to make the products work. It stays on your device, is never transmitted 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 is cached in the app's Caches directory so the app still shows real, previously verified content when you are offline.
• Android app — the educational content is bundled inside the app itself. The system WebView may keep an ordinary local cache of the most recent article list for offline use.
• Website — your browser may cache the article list according to normal HTTP caching rules. The site itself writes no cookies and stores no identifiers.

6. Children's privacy

ChainSources is a general-audience educational resource and is not directed at children under 13. We do not knowingly collect personal information from anyone, including children — because we collect no personal information at all. If you believe a child has somehow provided us with personal data, please contact us and we will address it.

7. 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 the standard security model of your operating system.

8. Your rights

Data protection laws such as the GDPR and CCPA give you rights to access, correct, delete or export the personal data a company holds about you. Because ChainSources holds no personal data about you, there is nothing for us to retrieve, amend, delete or export. You can remove all locally stored data at any time by clearing your browser storage or uninstalling the app. We do not sell or share personal information — we have none to sell or share.

9. 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.

10. Contact

You can also visit the ChainSources support page.