Announce heartbeat

Inform Presence that a user is still active. If the user has not been seen before, they will join the channel and send a join event.

Heartbeat has no functional effect on the performance or integrity of the client itself. It's only provided for Presence functionality. * Heartbeat is the mechanism used to "ping" back from the client to the server that the client is still online. The heartbeat is only germane to the Presence service.

It affects Presence in the following ways:

Subscribe calls and Heartbeat calls count as heartbeat signals to Presence, but only on the server RESPONSE does the heartbeat signal register. * Since a subscribe call can long poll, the server RESPONSE to the subscribe REQUEST may not be immediate (could be many minutes), so it's not always beneficial to rely on only the subscribe call as the heartbeat.
Since the server will RESPOND immediately to the client HP REST API call REQUEST, using the heartbeat call alongside subscribe calls is the perfect method for registering heartbeats with the Presence system.

Path Parameters
`sub_key` string — REQUIRED Your app's subscribe key from Admin Portal. Example: `sub-c-50264475-1902-558x-d213-7p19052012n2`
`channel` string — REQUIRED The channel name to perform the operation on. In the context of Presence, this parameter relates to a channel for which the new state will be applied or the existing state will be returned. Verify that channels are comprised of valid characters. You can use a single channel or multiple channels separated by a comma. Example: `myChannel`

Query Parameters
`channel-group` string Comma-separated list of channel group names to perform the operation on. In the context of Presence, this parameter relates to channel group name(s) to which you subscribe. You may subscribe to channels, channels and channel groups, or just channel groups. Example: `myChannelGroup`
`auth` string String which is either the auth key (PAM v2) or a valid token (Access Manager) used to authorize the operation if access control is enabled. Example: `myAuthKey`
`callback` string The JSONP callback name to wrap the function in. Example: `myCallback`
`heartbeat` integer Used to set the presence timeout period. It overrides the default value of `300` for Presence timeout. Example: `120`
`state` string When state is set, this value is an object with root keys associated with each channel you are setting state for. Each channel's state is an object. You must be present in a channel to set state for it. Example (SingleChannel): `%7B%22channel%22%3A%7B%22text%22%3A%22hey%22%7D%7D` Example (MultipleChannel): `%7B%22firstchannel%22%3A%7B%22text%22%3A%22hello%22%7D%2C%22secondchannel%22%3A%7B%22age%22%3A10%7D%7D`
`uuid` string — REQUIRED A UTF-8 encoded string of up to 92 characters used to identify the client. Example: `myUniqueUserId`
`signature` string Signature used to verify that the request was signed with the secret key associated with the subscribe key. If Access Manager is enabled, either a valid authorization token or a signature are required. Check Access Manager documentation for details on how to compute the signature.
`timestamp` integer Unix epoch timestamp used as a nonce for signature computation. Must have no more than ± 60 seconds offset from NTP. Required if `signature` parameter is supplied.

Responses

200

Success

Schema — OPTIONAL
`status` integer — OPTIONAL
`message` string — OPTIONAL
`service` string — OPTIONAL