The Connection class is the entry point of the software development kit. It provides access to the services of the {virt-product-fullname} {engine-name}'s REST API.

The parameters of the Connection class are:

  • url - Base URL of the {virt-product-fullname} {engine-name} API

  • username

  • password

  • ca_file - PEM file containing the trusted CA certificates. The ca.pem file is required when connecting to a server protected by TLS. If you do not specify the ca_file, the system-wide CA certificate store is used.

Connecting to the {virt-product-fullname} {engine-name}
connection =
  url: '',
  username: 'admin@internal',
  password: '...',
  ca_file: 'ca.pem',

The connection holds critical resources, including a pool of HTTP connections to the server and an authentication token. You must free these resources when they are no longer in use:


The connection, and all the services obtained from it, cannot be used after the connection has been closed.

If the connection fails, the software development kit will raise an Error exception, containing details of the failure.

For more information, see Connection:initialize.