BuildFlow Designer Agents

Flow Designer Agents vs Single-Prompt Agents

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 pathsYou want simplicity and flexibility
Deterministic logic is required (compliance, regulations)Open-ended conversations are preferred
Complex multi-step workflows are neededStraightforward conversational tasks
Multiple decision points and branchingSimple Q&A or support scenarios
Audit trails and guaranteed outcomes are importantQuick 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

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.

No. When creating an agent, you must choose one approach. However, you can create separate agents for different purposes and transfer calls between them.

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.

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.

Next Steps