Agents - Share sandbox previews through Cloudflare Tunnel

Sandboxes can expose a service running inside the container on a public preview URL through the sandbox.tunnels namespace. The SDK uses cloudflared inside the sandbox so you can share a running service without configuring exposePort() or a custom domain. By default, sandbox.tunnels.get(port) creates a quick tunnel on a zero-config *.trycloudflare.com URL — no Cloudflare account, DNS record, or custom domain required.