If you are using the Zendesk Widget, you may have noticed that the bot does not start unless it is prompted by the end user to do so. You may have also noticed that if the end user leaves the message field blank in the pre-chat form, the bot does not begin the conversation either.
If you want your bot to be able to send the first message (or at least provide the illusion of it), you will need to create a custom trigger in Zendesk Chat. This function can be structured to work in specific ways for specific end users, meaning that you can send a specific message for a returning end user, or another message for a new end user.
Please refer to Zendesk's article on proactive messaging to learn more.
Some things to be aware of:
The first message will not be sent from the agent that you've created for the bot. It will be sent from an undefined user that you define yourself in the trigger.
If you have enabled pre-chat form, you are still able to send the first message, but you will miss out on information such as the end user's visitor_email, as the pre-chat form will never be displayed to the end user.