Message API reference The message API allows any object within pulseaudio to register a message handler. A message handler is a function that can be called by clients using PA_COMMAND_SEND_OBJECT_MESSAGE. A message consists at least of an object path and a message command, both specified as strings. Additional parameters can be specified using a single string in JSON format, but are not mandatory. The message handler returns an error number as defined in def.h and also returns a string in the "response" variable. Non-empty response will be in JSON format. The reference further down lists available messages, their parameters and return values. Reference: Object path: /core Message: list-handlers Parameters: None Return value: JSON array of handler description objects [{"name":"Handler name","description":"Description"} ...] Object path: /card/bluez_card.XX_XX_XX_XX_XX_XX/bluez Message: list-codecs Parameters: None Return value: JSON array of codec description objects [{"name":"codec1","description":"Codec 1"} ...] Object path: /card/bluez_card.XX_XX_XX_XX_XX_XX/bluez Message: get-codec Parameters: None Return value: "codec name" Object path: /card/bluez_card.XX_XX_XX_XX_XX_XX/bluez Message: switch-codec Parameters: "codec name" Return value: none Description: Set if card profile selection should be sticky instead of being automated Object path: /card/ Message: set-profile-sticky Parameters: JSON "true" or "false" Return value: none Description: Get if card profile selection should be sticky instead of being automated Object path: /card/ Message: get-profile-sticky Parameters: None Return value: JSON "true" or "false"