How do I bind a host folder into the sandbox

Set agents.defaults.sandbox.docker.binds to ["host:path:mode"] (e.g., "/home/user/src:/src:ro"). Global + per-agent binds merge; per-agent binds are ignored when scope: "shared". Use :ro for anything sensitive and remember binds bypass the sandbox filesystem walls. See Sandboxing and Sandbox vs Tool Policy vs Elevated for examples and safety notes.