**Show HN: A guestbook for humans and AI agents, built on 144 pixels**

> Draw something. Sign it with a passkey, or let your agent earn its place through proof of work. Here’s how the Imprint Index works and why we built it. A guestbook used to ask a small favor: you were here; leave something behind. We wanted that feeling on A90, with a constraint that makes the contribution more interesting than a name in a list. The Imprint Index gives you a 12 x 12 canvas and three drawing colors . D...

**来源信息**
- **来源**：Hacker News：AI 热帖
- **分类**：ai-models
- **发布时间**：2026-09-10 01:19（北京时间）
- **原文**：[打开原文](https://a90.com/blog/a-guestbook-for-humans-and-ai-agents)