Getting Started with the Advanced Flow Designer

In September 2025, SynthFlow released Advanced Flow Designer, introducing several improvements over the original version:

Deterministic conversation flow: Conversations now move through each node in a predictable, step-by-step sequence. This makes outcomes more reliable and easier to debug.
Variable collection: Collect and store variables directly from users during calls, enabling more dynamic and personalized interactions.
Deterministic branching logic: Define concrete rules—for example, if the user asks for Sales, route them to the Sales flow.

When creating a new agent, you can choose between the Original Flow Designer and the Advanced Flow Designer.

Use the Original Flow Designer if you want a balance of flexibility and structure.
Use the Advanced Flow Designer if you need strict, deterministic business logic.

⚠️ Note: The Advanced Flow Designer is currently in beta, and we’re rapidly adding new features.

The following information applies to the new Advanced Flow Designer

Advanced Flow Designer Concepts

Flow Designer lets you visually build advanced, multi-step call flows for your AI agents. Instead of writing a single prompt, you design a graph of nodes—each handling a specific part of the conversation or logic.

Key Concepts

Global Settings: Apply to the entire flow. Set your agent’s system prompt, define fallback logic, and handle objections or special cases.
Nodes: The building blocks of your flow. Drag and connect nodes to map out your call logic.

Node Type	Description
Global Settings	Define agent-wide settings: Objections, Personality, Role, Goal
Greeting Message	Triggers at call start. Welcomes the user and sets context.
Instruction Node	The core node: speak, ask, invoke actions, set variables, or collect input.
Action Node	Standalone function call—ideal for database writes or third-party API integrations.
Branch Node	Decision point: inspects variables or results, then routes to one outgoing edge based on logic.
Jump To Node	Instantly redirects to another Instruction or Branch node. Useful for loops or shared subflows.
Call Transfer	Hands off from AI to a live agent or external endpoint, carrying over context if needed.
End Call Node	Sends a closing script, triggers cleanup actions, and ends the session. No further input allowed.

Building Your Flow

You can add steps and branches to your flow. Branches help your agent make decisions (like if/else logic). Steps are actions the agent will take.

Click Add to insert a step or branch.

Add a branch: Select Branch, enter a name (visible only to you), and describe when the agent should follow it.
Add a step: Select Step, enter a name (visible only to you), and describe what the agent should do. You can reference variables, custom actions, and action results in your prompt.

Enrich Your Flow with Extra Nodes

Extra nodes make your agent more capable and ready for complex scenarios:

Actions & Custom Actions: Click Add Action to insert a Real-Time Booking, Call Transfer, or your own custom action. Reference actions in your step prompt by typing # and selecting from the dropdown.
FAQ: Add common questions and answers. For complex queries, use branches instead.
Objections & Special Cases: Add instructions for handling difficult cases and objections.

Flow Designer Agents vs Single-Prompt Agents

Wondering about the difference between building a structured conversation flow and using a single prompt? Check out our guide:

Conversation Flow vs. Single Prompt

This page explains the pros and cons of each approach and helps you decide which is best for your use case.