Do workflows and automations cost anything to run?

A plain automation has no AI cost. Only steps that use the AI cost money, and AI usage is billed as a pass through at the provider's cost. For example, an email step where you write the message yourself, or build it in the visual email builder from its templates, does not use AI. An AI generated email, where you enter a prompt and the language model writes the email, does use AI and is charged. The step shows when it is AI generated, and you can turn that on or off.

Automation usage, such as runs started by inbound webhooks, carries a very small charge of one tenth of a cent.

The messages and calls a workflow sends, such as SMS, email and phone calls, are billed at their normal usage rates.