A tunnel is a public route with an expiry and an owner. Sandbox can publish an HTTP or WebSocket service from a running environment, or temporarily share a workstation service through an outbound relay. Neither path makes the destination private merely because its hostname is difficult to guess.

Managed tunnels publish one port from a Sandbox environment. The service must listen on 0.0.0.0; the controller records the tunnel and the worker reconciles its route and private edge network.

123sandbox tunnel create "$SANDBOX_ID" --port 3000
sandbox tunnel list "$SANDBOX_ID"
sandbox tunnel delete "$SANDBOX_ID" "$TUNNEL_ID"

Workstation sharing uses sandbox http PORT. The command opens an outbound WebSocket session to the relay, prints an ephemeral exact-host URL, and keeps the route alive only while the session remains connected.

1sandbox http 4321

The edge is scoped per sandbox, not discovered dynamically. A Docker worker creates a private internal network shared by the exposed sandbox and the tunnel edge, then writes an exact-host route. The route disappears when its tunnel, sandbox, TTL, or relay session disappears.

Public HTTP and WebSocket services are supported. Raw TCP and tunnel authentication are intentionally not claimed until they have real enforcement; confidential and restricted workloads are not eligible for public tunnels.

A proxied DNS record alone is not an origin firewall. When a service must not accept public ingress, use an outbound connector such as the documented Cloudflare Tunnel topology and close public origin ports only after end-to-end verification.

When proxying an origin, use a hostname-matching certificate and Full (strict) encryption. Never lower a zone to Flexible to make an edge route appear healthy. The detailed policy is in Sandbox security and the deployment workflow is in Sandbox operations.

Trace explains a request path; it does not authorize one. Use trace.yshubham.com for the browser-visible request walkthrough, inspect the Sandbox operation when a route change is ambiguous, and delete the route as soon as the review or demo ends.