# Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

`YAR_VERSION` (string)
`YAR_CLIENT_PROTOCOL_HTTP` (integer)
`YAR_OPT_PACKAGER` (integer)
`YAR_OPT_TIMEOUT` (integer)
`YAR_OPT_CONNECT_TIMEOUT` (integer)
`YAR_OPT_HEADER` (array)
  Since 2.0.4
`YAR_PACKAGER_PHP` (string)
`YAR_PACKAGER_JSON` (string)
`YAR_ERR_OKEY` (integer)
`YAR_ERR_OUTPUT` (integer)
`YAR_ERR_TRANSPORT` (integer)
`YAR_ERR_REQUEST` (integer)
`YAR_ERR_PROTOCOL` (integer)
`YAR_ERR_PACKAGER` (integer)
`YAR_ERR_EXCEPTION` (integer)