Privacy Policy

1. Who we are

This website (endril.com, "the Site") is maintained by Endril (李义洵) as a personal site of tools and notes about problem-solving, education practice, and automation systems. If you have any questions about this policy, contact us at author@endril.com.

2. Information we collect

We follow a "data minimization" principle:

• Information you provide: content and email you submit through comments, contact forms, or the tipping feature. Content submitted via comments may be publicly displayed on the Site after moderation; your email is used only to reply to or contact you and is never publicly displayed.
• Automatically collected technical data: access logs (IP address, browser type, visit time, referrer) for security and anonymous traffic analytics.
• Cookies and similar technologies: see Section 3.

We do not sell your personal information, and we do not share personally identifiable information with advertisers.

2.1 Comment avatars & nicknames (automatic email lookup)

To save you the trouble of setting an avatar manually, when you type your email address into the comment or reply form, this site looks up the publicly available avatar and a suggested nickname associated with that address and previews it in a popover above the input. How it works:

• QQ email addresses (@qq.com, @foxmail.com, @vip.qq.com): we request the public avatar from Tencent's public avatar service (q1.qlogo.cn). Your QQ number never appears in the page source — it is encrypted by this site into a non-reversible token that is only resolved to the real avatar address on our server.
• Other addresses (163, Gmail, Outlook, etc.): we query Gravatar (a public avatar service run by Automattic) to see whether a public avatar and nickname exist for that address. We only send a hash of your email address, never the address itself. Addresses without a Gravatar simply get the site's default coloured-initial avatar.
• Nickname sources (in priority order): ① a nickname you already used in a previously published comment on this site; ② the public display name from your Gravatar profile; ③ the local part of your email address (the part before @ — never the domain, and never your full email address). The suggestion is filled in only when the nickname field is empty, and you may change it to anything you like at any time.
• What becomes public: the avatar and nickname you use are displayed alongside your published comment. Your email address itself is never displayed publicly.
• Your switch: the popover includes a "Show this avatar with my comment" toggle — displaying it is entirely your choice. When off, new comments no longer carry an avatar, and you can also hide avatars on your previously published comments in one click (turn it back on to restore). The preference is stored only in a cookie in your browser (valid for one year) and is used solely for this toggle.
• Caching & rate limits: lookup results are cached in server memory for a short period (no more than 30 minutes) so responses stay fast; no long-term profile linking your email to your visits is built. The lookup endpoint is rate limited to prevent abuse such as bulk probing.

We do not use these avatars or nicknames for advertising or profiling, and we do not share them with third parties. To have a comment and its avatar removed, contact us at author@endril.com and we will handle it promptly.

3. Cookies and similar technologies

Cookies are small text files stored in your browser. We use two kinds:

• Strictly necessary cookies: required for basic site functions (e.g., remembering your theme preference).
• Third-party advertising cookies: we use Google AdSense to display ads. Google and its partners may use cookies (including _ga and advertising cookies) to serve personalized or non-personalized ads and to measure ad performance.

Visitors in the EU (GDPR) see a consent banner on their first visit and may accept or reject non-essential cookies. Rejecting does not affect your ability to browse the Site.

3.1 Location Card feature (geolocation)

The "Location Card" feature on the homepage lets you tap a dice button to generate a card showing the place name, latitude/longitude, elevation, climate zone, time zone, and sunrise/sunset, based on your browser's geolocation (Geolocation API).

• Local processing: your coordinates are used only in your browser to call public geo/weather APIs (Open-Meteo, OpenStreetMap Nominatim, Wikimedia Commons). They are never uploaded to our servers and are never stored by us.
• You are in full control: your browser asks for permission first; you may decline, in which case the feature will prompt you to enter a city name manually (which is likewise never reported).
• Caching: to reduce repeated requests, query results may be temporarily stored in your browser's localStorage (containing only public geo/weather data, with no personally identifiable information).

3.2 "Summon AI" feature

"Summon AI" provides you with AI-assisted capabilities such as chat. How it is implemented may evolve as the site grows, but the following two principles always apply regardless of the form it takes:

• Data minimization: unless genuinely necessary, no personal information is collected for this feature;
• Compliant use: even if limited information (such as chat content) must be processed for the feature in the future, it will be used solely to provide the feature itself, never for any illegal or non-compliant purposes, and always subject to the Section 2 restrictions ("no selling; no sharing with unrelated third parties").

If the feature's implementation involves third-party services, the handling of related data is covered by the general notes in Section 3.3 below; if new data-processing practices are introduced, we will update this policy first and make that clear on this page.

3.3 Third-party services (general)

Some features of this site may be provided by embedding, calling, or linking third-party services (e.g. AI chat services, public data APIs, advertising). When you use such features:

• Data is handled by the provider: your interaction with a third-party service (including anything you type and your account information) takes place within that third party's systems and is governed by its own privacy policy; we recommend reviewing it before use;
• Minimal transmission: this site only transmits the data necessary to make the feature work; in most cases, browser cross-origin isolation prevents this site from reading what you type into a third-party interface;
• No use, no transmission: third-party resources are loaded only when you actively use the corresponding feature.

4. Advertising (Google AdSense)

We use Google AdSense to serve ads. Google may serve personalized ads based on your browsing activity. You can:

• Opt out of personalized ads via Google Ads Settings;
• Manage third-party ad preferences via Your Online Choices (EU);
• Disable or clear cookies in your browser.

Google's privacy practices are governed by its Advertising Privacy Policy.

5. Your rights

Under applicable data protection laws (such as GDPR and CCPA), you have the right to access, correct, delete, and object to or restrict the processing of your personal data. To exercise these rights, email author@endril.com and we will respond within a reasonable time.

6. Changes to this policy

We may update this policy from time to time. Material changes will be posted on this page with an updated "Last updated" date. We recommend reviewing it periodically.