Inbenta recommends using the Session Data Keys to register the various events associated with an escalation to Agent Chat:

• CHAT_ATTENDED Indicates that a user accepted the escalation offer from the Chat app and that there were agents available to accept the chat.
• CHAT_ESCALATION_REJECTED Indicates that a user rejected the escalation offer from the Chat app.
• CHAT_NO_AGENTS Indicates that a user accepted the escalation offer from the Chat app but there were no available agents to accept the chat.
• CHAT_UNATTENDED Indicates that a user accepted the escalation offer from the Chat app, and there were available agents, but none of them got the chat.

These different data keys affect the numbers that appear in the "Sessions" graph in Dashboards > Sessions > Performance screen in the corresponding Chat instance. For more information about these dashboards, see Session Dashboards in Chat article in the Help Center.