Tunnel Access

Securely expose your sandboxes to the internet using built-in Cloudflare tunnels.

Overview

Tunnel Access creates secure Cloudflare tunnels that expose your local sandboxes to the internet. This allows cloud-hosted AI coding agents to connect to your sandbox without complex network configuration.

Each tunnel gets a unique *.coding-sandbox.dev URL that is encrypted end-to-end and requires no port forwarding or firewall changes.

Enabling Tunnel Access

Enable tunnels when creating a sandbox or on an existing one:

bash

# Enable tunnel during creation
csb create --agent claude --name my-project --tunnel

# Enable tunnel on an existing sandbox
csb tunnel enable my-project

Once enabled, you'll receive a public URL:

bash

csb tunnel info my-project
# URL: https://my-project-abc123.coding-sandbox.dev
# Status: Active
# Connected since: 2 minutes ago

Custom Domains

On the Pro plan and above, you can map custom domains to your tunnels:

bash

csb tunnel domain my-project --set dev.example.com

Custom domains require DNS configuration. Add a CNAME record pointing to the tunnel URL provided by Coding Sandbox.

Authentication

By default, tunnels are publicly accessible. You can add authentication to restrict access:

bash

# Require a token for access
csb tunnel auth my-project --token

# View the access token
csb tunnel auth my-project --show

Monitoring Tunnels

View tunnel status and traffic metrics in the dashboard or via CLI:

bash

# List all active tunnels
csb tunnel list

# View traffic stats
csb tunnel stats my-project

Security Considerations

All tunnel traffic is encrypted with TLS 1.3
Tunnels are isolated per sandbox — no cross-sandbox access
Tunnels are automatically disabled when a sandbox is stopped
Access tokens are rotated automatically every 24 hours

Production use

Tunnels are designed for development and testing. For production workloads, use dedicated infrastructure.

Sandbox Management

Settings