T3 Code
Open source control panel for the coding agents on your machine, with desktop and mobile apps
Anthropic Sandbox Runtime (srt)
OS level sandbox for agents and MCP servers, no container needed
About
Sandbox Runtime (srt) is the same sandboxing layer Anthropic uses for Claude Code's bash tool, released as a standalone CLI and library. It hit GitHub trending this week. It uses native OS primitives, Seatbelt on macOS and bubblewrap on Linux, with an alpha Windows backend, plus a proxy for network allowlists.
## What it does Prefix a command with `srt` and it runs inside a sandbox that applies to the whole process tree. Writes are denied by default except where you allow them, network access is limited to an allowlist of domains, and you can block reads of sensitive paths like `~/.ssh`. ## Sandboxing MCP servers The most useful trick: change an MCP server's command in `.mcp.json` from `npx ...` to `srt npx ...`, then set rules in `~/.srt-settings.json`. A local MCP server can then only touch the folders and hosts you picked. ## Good to know It is a beta research preview, so config formats may change. It is also usable as a TypeScript library if you are building your own agent harness.
Features
- Filesystem read and write rules applied to the whole process tree
- Network allowlist through a filtering proxy
- Seatbelt on macOS, bubblewrap on Linux, Windows in alpha
- Wraps local MCP servers with a one word change
- No Docker or container image needed
- CLI and TypeScript library
Install
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