AprilNEA - Full Stack Engineer

What's inside Claude Code Web: an unstripped Go binary, Anthropic's secret deployment platform, and the architecture of an AI-native PaaS The Starting Point We are building ArcBox, a full-stack platform from Desktop to Platform, similar to Railway and E2B in positioning. Our core philosophy is local-cloud consistency: replacing OrbStack with a fully open-source ArcBox Desktop that provides Sandbox capabilities locally. Recently, we noticed more and more Coding Agent platforms launching web-based entry points, and remarkably, nearly all of them chose Firecracker under the hood. Claude Code is no exception. As practitioners in the same space, curiosity about its runtime environment led to some digging. What began as a casual strace -p 1 turned into a full reverse-engineering session that uncovered unreleased Anthropic infrastructure, including an entirely undocumented application hosting platform. Everything described here was discovered through standard Linux tooling (strace, strings, objdump, go tool objdump) running inside a Claude Code session. No exploits, no privilege escalation, no network attacks. The binary was sitting right there, unstripped, with full debug symbols. Layer 1: It's a Firecracker MicroVM The first question: what exactly is this environment?