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title: Flow Designer Agents vs Single-Prompt Agents
slug: conversation-flow-vs-single-prompt
description: Compare Flow Designer and Single-Prompt agents to choose the right approach for your use case.
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When building AI voice agents with Synthflow, you have two primary approaches: **Flow Designer Agents** (structured, deterministic) and **Single-Prompt Agents** (flexible, conversational). Understanding the differences will help you choose the right tool for your use case.

## Flow Designer vs Single-Prompt Agents

| Use Flow Designer When...                                 | Use Single-Prompt Agents When...       |
| --------------------------------------------------------- | -------------------------------------- |
| You need structured control over conversation paths       | You want simplicity and flexibility    |
| Deterministic logic is required (compliance, regulations) | Open-ended conversations are preferred |
| Complex multi-step workflows are needed                   | Straightforward conversational tasks   |
| Multiple decision points and branching                    | Simple Q\&A or support scenarios       |
| Audit trails and guaranteed outcomes are important        | Quick prototyping is the priority      |

## Key Differences

### Flow Designer Agents

**How it works:**

* Visual, node-based system where conversations follow explicit, pre-defined paths
* Each node represents a specific step or decision point
* Variables store information collected during conversations
* Branches create if/else logic based on conditions

**Best for:**

* Compliance-heavy scenarios (healthcare, finance, legal)
* Multi-step processes with 5+ steps
* Complex branching logic
* Integration-heavy workflows with multiple API calls
* Scenarios requiring audit trails

### Single-Prompt Agents

**How it works:**

* One comprehensive prompt that guides the AI's behavior throughout the conversation
* The AI makes autonomous decisions based on context
* Responses adapt naturally to user input
* No predefined conversation paths

**Best for:**

* Open-ended customer support
* Simple Q\&A or FAQ scenarios
* Quick prototyping and MVPs
* Natural, conversational interactions
* Scenarios where flexibility is more important than control

## FAQ

<AccordionGroup>
  <Accordion title="Can I switch approaches after deploying?">
    Yes, but you'll need to rebuild the agent. Make sure to test thoroughly before switching a live agent, or create a new agent and gradually transition users.
  </Accordion>

  <Accordion title="Can I use both approaches in one agent?">
    No. When creating an agent, you must choose one approach. However, you can create separate agents for different purposes and transfer calls between them.
  </Accordion>

  <Accordion title="Which approach handles unexpected user input better?">
    Single-Prompt agents are generally more flexible with unexpected input, as the AI can improvise. Flow Designer agents require explicit handling of edge cases, but this also means more control.
  </Accordion>

  <Accordion title="How do I know if my prompt is too complex for Single-Prompt?">
    If you're writing many conditional statements ("if X, then Y"), have more than 3-4 distinct conversation stages, or struggle to maintain consistency, consider Flow Designer.
  </Accordion>
</AccordionGroup>

## Next Steps

* [Get Started with Flow Designer](/flow-designer) to build structured conversation flows
* [Learn About Single-Prompt Agents](/about-prompting) for flexible, conversational agents
* [Explore Multi-Agent Systems](/multi-agent-system) to organize complex flows