matrix-spec/event-schemas/schema/v1/m.room.message#m.audio

{
    "type": "object",
    "title": "AudioMessage",
    "description": "This message represents a single audio clip.",
    "allOf": [{
        "$ref": "core-event-schema/room_event.json"
    }],
    "properties": {
        "content": {
            "type": "object",
            "properties": {
                "msgtype": {
                    "type": "string",
                    "enum": ["m.audio"]
                },
                "body": {
                    "type": "string",
                    "description": "A description of the audio e.g. 'Bee Gees - Stayin' Alive', or some kind of content description for accessibility e.g. 'audio attachment'."
                },
                "url": {
                    "type": "string",
                    "description": "The URL to the audio clip."
                },
                "info": {
                    "type": "object",
                    "title": "AudioInfo",
                    "description": "Metadata for the audio clip referred to in ``url``.",
                    "properties": {
                        "mimetype": {
                            "type": "string",
                            "description": "The mimetype of the audio e.g. ``audio/aac``."
                        },
                        "size": {
                            "type": "integer",
                            "description": "The size of the audio clip in bytes."
                        },
                        "duration": {
                            "type": "integer",
                            "description": "The duration of the audio in milliseconds."
                        }
                    }
                }
            },
            "required": ["msgtype", "body", "url"]
        },
        "type": {
            "type": "string",
            "enum": ["m.room.message"]
        }
    }
}