Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The HTTP Permissions-Policy header serial directive controls whether the current document is allowed to use the Web Serial API to communicate with serial devices, either directly connected via a serial port, or via USB or Bluetooth devices emulating a serial port.
Specifically, where a defined policy blocks use of this feature, Serial.requestPort() and Serial.getPorts() calls will return a Promise that rejects with a DOMException of type SecurityError.
Permissions-Policy: serial=<allowlist>;<allowlist>A list of origins for which permission is granted to use the feature. See Permissions-Policy > Syntax for more details.
The default allowlist for serial is self.