Single prompt agents
You write one prompt that covers the agent’s persona, goals and rules, and the agent follows it for the whole call. You can add a fixed welcome message and let the agent end the call when the caller is done. For most receptionist, FAQ and simple lead-capture agents, this is all you need.
Single prompt agents are the only type you can create and edit through the public API.
Flow agents
You build the conversation on a canvas out of nodes (steps) connected by transitions (the conditions for moving between steps). Each node has its own job. One might talk with the caller, another collects details, calls your system or transfers the call. A global prompt holds the persona and shared rules, and every node uses it.
Use a flow agent when the call has to follow a set process. Examples are verifying details before an action, branching on what your CRM returns, sending an SMS mid-call or handing the caller to a specific person.
Comparison
How to choose. Pick a single prompt agent when the call is an open conversation: answering questions, giving information, general support. Pick a flow agent when the call follows a fixed process: collecting and checking details, calling your systems, or routing the caller to the right place. If you start with a single prompt and later need a flow, your prompt is a good starting point for the flow’s global prompt.
Both types share
- The same voices, pronunciation overrides and speech-to-text vocabulary.
- Provided and extracted variables.
- A built-in call simulator for test calls from the browser.
- Versioning: you edit a draft, and phone calls only see your changes after you click Deploy.
Next: Single prompt agents · Flow agents · Writing a good prompt