# Send a channel message

> Learn about voice channels in Vivox Core.

You can send a channel message by using the vx\_req\_session\_send\_message request. All participants in the channel receive the message.

```plaintext
typedef struct vx_req_session_send_message
{
    /**
    * The common properties for all requests
    */
    vx_req_base_t base;
    /**
    * Handle returned from successful vx_req_sessiongroup_add_session request
    */
    VX_HANDLE session_handle;
    /**
    * HTTP Content type of the message.
    * If an empty string is passed in, this field will default to "text/plain".
    * This field will be validated, so it must be in a valid format.
    * For a full description of valid content types, see RFC 2046 (https://www.ietf.org/rfc/rfc2046.txt).
    */
    char *message_header;
    /**
    * The contents of the message.
    * \note The message body must not exceed the length specified by the server in its pre-login configuration.
    * The default max message length is 320 bytes (320 characters UTF-8).
    */
    char *message_body;
    /**
    * The language (default null, implies "en").
    */
    char *language;
    /**
    * Namespace of the custom application stanza (optional, default null).
    */
    char *application_stanza_namespace;
    /**
    * Custom application stanza body (optional, default null).
    */
    char *application_stanza_body;
}

vx_req_session_send_message_t;
```

For more information, see [Group text messages](../../../developer-guide/messaging/group-text-messages).