FAQ
General
Is Shield CLI free?
The Shield CLI client is open source and free. The public tunnel service has a free tier — check the website for details.
Which operating systems are supported?
macOS, Linux, and Windows, with amd64, arm64, 386, and armv7 architectures.
Are there any dependencies?
No. Shield CLI is a single binary — download and run.
Connections
How many apps can I connect simultaneously?
In Web UI mode, up to 3 concurrent connections. CLI mode connects to 1 service at a time.
Does it auto-reconnect on disconnect?
Yes. Shield CLI has built-in auto-reconnect with exponential backoff, up to a maximum interval of 10 seconds.
Do Access URLs expire?
Access URLs are valid while the tunnel is connected. They become invalid once disconnected.
Can multiple people use the same URL?
Yes. The same Access URL can be accessed from multiple browsers simultaneously.
Security
Is the data transfer secure?
All data is transmitted through WebSocket encrypted tunnels. Local credentials use AES-256-GCM encryption.
Are passwords stored on the server?
No. Target service passwords are used only during connection establishment and are not persisted on the server.
What is a machine fingerprint?
A unique identifier generated from your machine's hardware information. It's used to derive encryption keys and identify the connector. It contains no personal information.
Network
GitHub is slow in China — what can I do?
Use the jsDelivr CDN mirror:
curl -fsSL https://cdn.jsdelivr.net/gh/fengyily/shield-cli@main/install.sh | shDoes it work behind a corporate proxy?
Shield CLI uses WebSocket for tunneling. WebSocket can typically traverse HTTP proxies via the CONNECT method. If it doesn't work, check with your network admin whether WebSocket connections are allowed.
What firewall ports are needed?
Shield CLI only requires outbound connections to the public gateway on port 62888 (WebSocket). No inbound ports need to be opened.
Configuration
Where are app configurations stored?
Encrypted locally:
- macOS / Linux:
~/.shield-cli/ - Windows:
%LOCALAPPDATA%\ShieldCLI\
Can I sync configurations across machines?
Not currently. Each machine's configuration and credentials are independent (encrypted with each machine's unique fingerprint).