diff --git a/README.md b/README.md
index 261127d..5815a47 100644
--- a/README.md
+++ b/README.md
@@ -24,16 +24,38 @@
   <a href="README.zh.md">简体中文</a>
 </p>
 
-VibeBox is a lightweight, ultra-fast sandbox that lets AI agents run commands, modify files, and execute code freely
-without permission prompts securely. It is completely isolated using Apple's Virtualization Framework, so your actual
-system
-stays
-safe with minimal memory and disk usage.
+VibeBox is a lightweight, ultra-fast sandbox for AI agents to run commands, edit files, and execute code inside an
+isolated Apple Virtualization Framework micro-VM, no repeated permission prompts, minimal memory/disk overhead.
 
 [![VibeBox Terminal UI](docs/screenshot.png)](https://vibebox.robcholz.com)
 
 ---
 
+### Why I built VibeBox
+
+I use agents like Codex and CC a lot, but I always felt uneasy running them directly on my host machine. If I lock
+things
+down, I get interrupted by constant “are you sure?” prompts. If I loosen it up, I worry the agent might touch the
+wrong files or run something I didn’t intend.
+
+I wanted something that feels as frictionless as giving an agent a real shell, but with a hard isolation boundary. So I
+built VibeBox: a per-project micro-VM sandbox that starts fast, keeps changes contained to the repo, and lets me iterate
+without babysitting permissions.
+
+### Comparison
+
+Here’s why I didn’t just use existing options:
+
+- **vibe**: super convenient, but it’s too minimal for what I need. It lacks basic configuration, and it doesn’t give me
+  the multi-instance + session management my workflow wants.
+- **QEMU**: powerful, but the configuration surface area is huge. For day-to-day sandboxing it’s not “open a repo and
+  go” — it’s a project on its own.
+- **Docker / devcontainers**: great ecosystem, but for daily use it feels heavy. Cold starts can be slow, and it’s not
+  something I can jump into instantly, repeatedly, all day.
+
+That’s what pushed me to build **VibeBox**: I wanted a per-project sandbox that’s fast to enter (just `vibebox`),
+supports real configuration + sessions, and keeps a hard isolation boundary.
+
 ### Installation
 
 ```bash
diff --git a/README.zh.md b/README.zh.md
index f2757ab..a527eea 100644
--- a/README.zh.md
+++ b/README.zh.md
@@ -31,6 +31,25 @@ Apple 的 Virtualization Framework 做到彻底隔离，所以无论 Agent 在
 
 ---
 
+### 我为什么做 VibeBox
+
+我平时经常用像 Codex 和 CC 这样的
+agent，但一直不太敢让它们直接在我的宿主机上跑。把权限收紧一点，就会被各种“你确定吗？”的确认弹窗不停打断；放松一点，又担心它哪天误操作，碰到不该碰的文件，或者跑了我没打算执行的命令。
+
+我想要的是一种体验：像给 agent 一个真实 shell 一样顺滑，但同时又有一道硬隔离的安全边界。于是我做了 VibeBox：一个按项目划分的
+micro-VM 沙箱，启动很快，改动被限制在仓库范围内，让我可以更高频地迭代，而不用一直盯着权限确认。
+
+### 对比
+
+下面是我为什么没有直接用现成方案的原因：
+
+- **vibe**：非常方便，但对我来说太“极简”了。它缺少一些基础配置能力，也没法提供我工作流里需要的多开和 session 管理。
+- **QEMU**：很强大，但配置面太大了。日常当沙箱用，它不像是“进到 repo 就能用”，更像是你得先把它当成一个项目来折腾。
+- **Docker / devcontainers**：生态很成熟，但日常使用对我来说偏重。冷启动有时会慢，而且它不是那种我能一天反复、随时秒进秒出的工具。
+
+这些就促使我做了 **VibeBox**：我想要一个按项目隔离的沙箱，进入速度快（直接用 `vibebox`），支持真正可用的配置和
+sessions，同时还保留明确的硬隔离边界。
+
 ### 安装
 
 ```bash