Anthropic Open-Sources sandbox-runtime (srt): OS-Level Process Sandboxing Without Containers — Seatbelt/Bubblewrap, 84% Fewer Permission Prompts

Anthropic Experimental·high signal

Anthropic's srt is a lightweight open-source tool that enforces filesystem and network restrictions at the OS level without containers. Write access denied everywhere by default — explicitly allowlist paths. Network traffic routes through a proxy enforcing domain allowlists. In internal usage, sandboxing reduces permission prompts by 84%. Works with macOS Seatbelt and Linux bubblewrap — can sandbox arbitrary processes, agents, and MCP servers.