> ## Documentation Index
> Fetch the complete documentation index at: https://docs.kraken.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Heartbeat

> FIX message used to maintain session connectivity and confirm the application is functioning normally.

The Heartbeat message is used to maintain session connectivity and indicate that the application is functioning normally. Heartbeat messages are sent periodically based on the HeartBtInt from Logon, in response to Test Request messages, or when no other messages have been sent within the heartbeat interval.

<Tabs>
  <Tab title="FIX Specification">
    <ParamField path="header" type="" required>
      MsgType <code>0</code>
    </ParamField>

    <ParamField path="112 - TestReqID" type="string" required>
      Required when the heartbeat is the result of a Test Request message.
    </ParamField>

    <ParamField path="trailer" type="" required />
  </Tab>
</Tabs>