Cloudflare 发布 Precursor：用连续客户端信号检测代理行为
原标题：Introducing Precursor: detecting agentic behavior with continuous client-side signals
AI 摘要
Cloudflare 推出 Precursor，一种基于客户端会话的验证系统，通过动态注入 JavaScript 持续收集用户行为信号，以区分人类与自动化流量。该系统补充了 Turnstile，覆盖整个应用的用户旅程，利用人类行为的物理约束（如手腕转动、认知延迟、手抖）识别难以模拟的机器人行为。Precursor 已集成到企业版 Bot Management 中，旨在减少对合法用户的干扰，并提高机器人攻击的成本。
正文节选
Bot mitigation is an adversarial game: attackers adapt, defenders respond, and the cycle continues. At Cloudflare, we stay ahead by combining visibility across our global network with signals from the client-side environment. At the network level, we analyze over 1 trillion requests per day to understand reputation, patterns, and anomalies across more than 20% of the web. On the client side, we’ve pushed detection deeper with Cloudflare Turnstile, which has evolved from a CAPTCHA replacement to