Retell provides two approaches to building your conversational agent:
Create Agent Interface
  1. Single Prompt: Design your agent with one comprehensive prompt
  2. Multi-Prompt Tree: Structure your agent with multiple organized prompts

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Single Prompt Agent

The single prompt approach allows you to define your agent’s behavior with one comprehensive prompt. It’s straightforward and great for simple use cases.
Single Prompt Agent
While this approach is an excellent starting point, you may encounter several challenges as your agent becomes more complex:
  1. The agent may start to hallucinate or deviate from instructions
  2. Function calling becomes less reliable
  3. The prompt becomes difficult to maintain as it grows larger
Due to these limitations, we recommend using the multi-prompt approach for more sophisticated agents.

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Multi-Prompt Agent

Multi Prompt Agent
The multi-prompt approach allows you to create a structured tree of prompts. Each node in the tree can contain:
  • Its own specific prompt
  • Custom function calling instructions
  • Clear transition logic to other nodes
For example, our “Lead Qualification” template demonstrates this structure:
Multi Prompt Agent
In this template, we break down the conversation into two distinct steps:
  1. Lead Qualification: Gather and verify all required information
  2. Appointment Scheduling: Book the appointment only after successful qualification
This structured approach prevents common issues found in single-prompt agents, such as premature appointment booking before completing the qualification process. The multi-prompt structure ensures your agent follows the correct sequence of steps and maintains context throughout the conversation.