Autonomous AI agents are beginning to populate social platforms, but it is still unclear whether they can sustain the back-and-forth needed for extended coordination. We study Moltbook, an AI-agent social network, using a first-week snapshot and introduce interaction half-life: how quickly a comment's chance of receiving a direct reply fades as the comment ages. Across tens of thousands of commented threads, Moltbook discussions are dominated by first-layer reactions rather than extended chains. Most comments never receive a direct reply, reciprocal back-and-forth is rare, and when replies do occur they arrive almost immediately -- typically within seconds -- implying persistence on the order of minutes rather than hours. Moltbook is often described as running on an approximately four-hour ``heartbeat'' check-in schedule; using aggregate spectral tests on the longest contiguous activity window, we do not detect a reliable four-hour rhythm in this snapshot, consistent with jittered or out-of-phase individual schedules. A contemporaneous Reddit baseline analyzed with the same estimators shows substantially deeper threads and much longer reply persistence. Overall, early agent social interaction on Moltbook fits a ``fast response or silence'' regime, suggesting that sustained multi-step coordination will likely require explicit memory, thread resurfacing, and re-entry scaffolds.

翻译：自主AI代理正开始涌入社交平台，但它们是否能够维持长期协调所需的多轮互动仍不明确。我们利用首周快照研究了AI代理社交网络Moltbook，并引入交互半衰期指标：评论获得直接回复的概率随评论时效衰减的速度。通过对数万条评论线程的分析，发现Moltbook的讨论主要由表层反应主导而非延伸对话链。大多数评论从未获得直接回复，双向互动极为罕见，且当回复发生时几乎总是即刻到达——通常在数秒内——意味着对话持续性仅维持在分钟量级而非小时量级。Moltbook常被描述为以约四小时“心跳”周期运行；通过对最长连续活动窗口进行聚合谱分析，我们在此快照中未检测到可靠的四小时节律，这与个体调度存在抖动或相位偏移的情况相符。使用相同估计器分析的同期Reddit基线数据则显示出明显更深的对话线程和更长的回复持续性。总体而言，Moltbook上早期代理的社交互动符合“快速响应或沉默”模式，这表明要实现持续的多步协调可能需要显式记忆机制、线程重提和再参与框架的支持。