1. 核心原则：本地优先与有限使用

「歧路 Diverge」（以下简称“本服务”或“我们”）是一款面向广大棋手的双引擎复盘与人类直觉分析工具。我们的核心设计哲学是纯浏览器端本地处理（100% In-Browser Local Processing）：

• 无自建用户数据库：我们不设立收集用户个人资料或对局档案的私有数据库，无需注册账号即可完整使用。
• 纯本地计算：Stockfish 19（WebAssembly）与 Maia-3 深度神经网络的计算推理均直接在您的设备硬件（CPU/GPU 内存）中独立完成。
• 有限使用承诺：我们承诺绝不出售、出租任何用户数据，绝不将数据用于个性化广告、再营销或信用评估。

2. 本地处理的数据披露（依照 Chrome 商店规范）

根据 Chrome 应用商店开发者计划政策与《用户数据常见问题（User Data FAQ）》，即便数据仅在您的客户端设备本地处理、未传输至开发者服务器，我们亦必须如实向您披露其范围与目的：

(1) 网页内容与棋盘局面数据 (Website Content & Chess Data)

• 处理范围：当您在受支持的国际象棋平台（lichess.org 与 chess.com）浏览分析板、学习研究室、战术习题或已完赛对局页面时，本扩展的内容脚本会在当前页面内存中读取：
  1. 当前棋盘的 FEN 局面字符串与走法坐标；
  2. 历史记谱（SAN / UCI / PGN 走法记录）；
  3. 双方棋手的公开对局昵称（Usernames）与公开段位等级分（Ratings）；
  4. 对局状态证据（时钟运行状态、投降/认输按钮状态、终局裁判结果）。
• 处理目的：用于在本地驱动 Maia-3 预测走法注意力热力图、计算人类直觉走法概率、调用 Stockfish 19 进行胜率与损耗评估，并在复盘工作台顶部展示对局双方信息。同时，FairPlayGuard 守卫依靠时钟与终局状态检测实时比赛，并在对局中强制切断所有引擎计算以恪守反作弊守则。
• 生命周期：以上数据仅临时存在于当前标签页的运行时内存中，随着标签页关闭或切局即刻释放，绝不留存或持久化上传。

(2) 本地持久化偏好设置 (User Preferences via chrome.storage.local)

• 存储内容：
  1. 用户选定的目标直觉等级分（Elo: 1100、1500、1900、2200）；
  2. 界面显示语言（简体中文 / English）；
  3. 棋盘视觉开关（意图热力图开关、走法建议箭头开关）；
  4. 悬浮面板收起状态与悬浮球停靠坐标。
• 隐私界限：这些配置仅保存在您本地浏览器的扩展专有沙箱中，我们无法远程读取或同步，您可随时在浏览器中卸载扩展或清除数据进行彻底清除。

3. 网络请求与数据代理机制核对

为了保证纯静态 Web 环境下的对局导入功能与神经网络权重下载，本扩展涉及以下透明、安全的网络交互：

(1) 棋局公开导出与边缘代理请求 (Game Data & Edge Proxy)

当您在全盘分析页导入已完赛对局时：

• Lichess 平台：扩展直接向 Lichess 官方公开 API（https://lichess.org/game/export/{gameId}）发起单向只读 GET 请求，拉取公开棋谱。
• Chess.com 平台：由于第三方平台直接发起的跨域限制（CORS）与安全策略，扩展会请求位于 https://4chess.cc/api/chesscom?id={gameId} 的 Cloudflare Pages 边缘代理端点。

(2) 神经网络模型权重下载 (Model Weights CDN)

• 请求内容：首次运行或切换模型规格时，扩展从高速静态 CDN（https://weights.4chess.cc/...）下载 Maia-3 开源神经网络模型二进制权重（5M 规格约 28MB，23M 规格约 104MB）。
• 下载存储：下载后的权重直接写入您设备本地浏览器的 IndexedDB 存储（ModelCache），实现后续使用瞬间秒开与离线复用。
• 无回传追踪：此过程为标准的大文件静态 CDN 下载，不携带也不回传任何用户行为、身份或对局数据。

4. 第三方服务与数据共享

我们不与任何第三方数据经纪商、广告商或统计分析机构共享任何数据：

• 本服务不包含任何第三方跟踪 SDK、广告脚本、数据埋点或行为统计分析代码（Google Analytics、Facebook Pixel 等均未引入）。
• 扩展与工作台的所有网络通信仅限于上述公开棋谱获取与静态模型权重拉取。

5. 儿童隐私保护

本服务为通用的国际象棋分析工具，不面向 13 岁以下儿童单独收集任何个人身份信息。由于本服务不在远端服务器收集或存储任何用户数据，所有年龄段棋手均在完全相同的本地安全沙箱环境下使用。

6. 您的权利与数据清除

因为我们不在服务器端保存任何关于您的账户、身份或对局数据，所以不存在远端个人档案需要申请删除或注销：

• 清除本地数据：您只需在 Chrome 浏览器中访问 chrome://extensions，点击本扩展的「详情」→「清除扩展数据」，或直接「移除扩展」，即可秒级彻底抹除本机保存的全部偏好配置与 IndexedDB 模型缓存。

7. 政策更新与联系方式

若本扩展引入重大架构调整或新增涉及用户数据的特性，我们将在更新说明与本页面同步更新生效日期。

如果您对本隐私政策或本地数据处理有任何疑问，请随时联系开发者：

• 联系邮箱： [email protected]
• 开源项目主页与工单： https://github.com/keluoke/4chess

1. Core Principles: Local-First & Limited Use

Diverge (歧路) ("we", "us", or "our") is a dual-engine chess review and human intuition analysis workbench. Our foundational architectural principle is 100% In-Browser Local Processing:

• Zero Remote User Databases: We maintain no remote databases that collect, track, or monitor your personal profile or chess match records. No account registration is ever required.
• Client-Side Inferences: Both Stockfish 19 (WebAssembly) and Maia-3 deep neural networks run directly inside your client device's browser memory (CPU/GPU).
• Strict Limited Use: We commit never to sell, license, or monetize your data, and never to use your data for advertising, remarketing, or credit/lending scoring.

2. Disclosure of Locally Processed Data (Chrome Store Requirement)

Per Google Chrome Web Store Developer Program Policies and the User Data FAQ, even when user data is processed solely on the client machine and never sent to a remote server, developers must disclose its scope, purpose, and handling:

(1) Webpage Content & Chess Board Data

• Scope: When you navigate analysis boards, studies, puzzles, or concluded match archives on supported platforms (lichess.org and chess.com), the extension's content scripts read directly from the active tab's runtime memory:
  1. Board position strings (FEN) and legal move coordinates;
  2. Notation records (SAN / UCI / PGN move lists);
  3. Public player usernames and platform ratings;
  4. Match termination evidence (active clock countdown, resignation buttons, game-over banners).
• Purpose: Exclusively to drive client-side Maia-3 attention heatmap rendering, compute human intuition probabilities, execute Stockfish 19 centipawn evaluations, and display player labels on the review studio. Furthermore, our FairPlayGuard uses clock and result states to guarantee complete engine lockout during live matches in accordance with fair-play rules.
• Retention: This information is processed strictly in temporary tab memory and is instantaneously discarded upon tab closure or position change. It is never logged or uploaded to any remote server.

(2) Local Client Storage (chrome.storage.local)

• Stored Items:
  1. Default target intuition Elo rating (1100, 1500, 1900, 2200);
  2. Interface language preference (zh-CN / en);
  3. Visual overlay toggles (heatmap toggle, candidate arrows toggle);
  4. Floating panel minimized state and floating ball dock coordinates.
• Privacy Boundary: These values remain entirely within your local Chrome profile sandbox. We have zero remote access to them, and they are never synced to our servers.

3. Network Requests & Edge Proxy Audit

To enable PGN imports and neural network weight loading in a secure web environment, the extension engages in the following transparent network calls:

(1) Public Game Imports & Edge Proxy Requests

When you import a finished match in the Full Game Analysis studio:

• Lichess: The extension sends a direct, unauthenticated GET request to Lichess's public API (https://lichess.org/game/export/{gameId}) to retrieve public PGNs.
• Chess.com: Due to CORS and browser-side CSP restrictions, the extension queries a dedicated Cloudflare Pages edge proxy endpoint: https://4chess.cc/api/chesscom?id={gameId}.

(2) Neural Network Model Weights Delivery

• Operation: Upon initial use or model switching, the extension downloads Maia-3 open-source neural network weights (5M model ~28MB, 23M model ~104MB) from our high-speed static CDN (https://weights.4chess.cc/...).
• Client Cache: The binary weights are saved directly to your browser's local IndexedDB (ModelCache) for instant subsequent launches and offline review capability.
• No Telemetry: This is a purely static GET file transfer without telemetry, analytics, or user fingerprinting.

4. Third-Party Sharing

We do not share, sell, or transfer any user data to third parties, data brokers, or advertising networks:

• The extension contains zero tracking SDKs, zero advertising modules, and zero third-party telemetry libraries (such as Google Analytics).
• All network communication is restricted exclusively to public chess exports and static model delivery as detailed above.

5. Children's Privacy

Diverge is a general-purpose chess review utility and does not knowingly collect personal information from children under 13. Because our architecture handles data locally without server-side user profiles, all users operate within the identical private, local sandbox.

6. Your Rights & Data Deletion

Because no personal information or chess games are stored on our servers, there is no remote account or database record to request deletion for:

• Wiping Local Data: You can permanently erase all local preferences, cached boards, and IndexedDB model weights at any moment by navigating to chrome://extensions, clicking Details on Diverge, and selecting Clear data, or by simply uninstalling the extension.

7. Contact Us

If you have any questions or feedback regarding this Privacy Policy or our local data practices, please contact:

• Email: [email protected]
• GitHub Repository & Issues: https://github.com/keluoke/4chess