Workflow Builder

Overview

Sulus's Workflow builder is a visual interface for creating deterministic conversation flows using nodes and edges. Here's a comprehensive overview of all available node types and how they connect.

Deprecation notice: Workflows are being retired on August 18, 2026. From that date onward, existing workflows will no longer run. If you have a workflow in production, migrate it to an Assistant (for a single-flow use case) or a Squad (for multi-step, multi-specialist flows) before the retirement date. New builds should use an Assistant or Squad directly rather than a new Workflow — see Squad Routing: Handoff Destinations & Context Engineering and the worked Squad walkthroughs in the Setup category for the modern equivalent of the patterns described below.

Conversation Node

The default and most commonly used node type — it's the main building block for conversation flows. Configuration options include:

• First Message – The initial spoken message when entering the node (useful when you want the agent to speak first)
• Prompt – Detailed instructions guiding agent responses; this is the most important part of the node
• Model / Voice / Transcriber Settings – Configure AI model, voice, and transcription per node
• Extract Variables – Gather variables from the conversation using liquid syntax ({{ variable_name }}), with support for String, Number, Boolean, and Integer types

API Request Node

Allows you to make HTTP GET or POST requests to custom endpoints or automation services. Request bodies must be formatted in JSON Schema.

Transfer Call Node

Transfers the call to another phone number (human agents or specialized voice agents). You can configure:

• A destination phone number
• A transfer plan — a message or summary spoken to the receiving party before connecting

End Call Node

A terminal node that explicitly ends the call. You can configure an optional closing message via the First Message field.

Workflows without a defined End Call Node risk unintended minutes usage. Always include clear termination points.

Tool Node

Integrates tools from your existing Tools library. Tools created in the Tools section are automatically available — just select the tool from the dropdown in the node.

Global Node

Routes to this node from any point in the workflow. Commonly used for escalation (e.g., transferring to a human agent at any stage). You must:

• Enable the Global toggle
• Specify an Enter Condition that triggers routing to this node

Nodes are connected via edges, and each edge can have a condition that must be satisfied for the flow to proceed. There are three condition types:

AI-based conditions (plain language, evaluated by LLM):

User wanted to talk about voice agents

Logical conditions (using extracted variables):

{{ city == "San Francisco" }}

Combined conditions (mixing operators and variables):

{{ customer_tier == "VIP" or total_orders > 50 }}

• Every workflow must have exactly one start node
• The default start node is a Conversation Node, but it can be changed to any other node type
• Start nodes cannot be deleted
• Nodes without an End Call Node risk the call never terminating

• Map flows first – Plan all possible user journeys before building
• Keep prompts focused – Each node should have a single, clear purpose
• Extract variables as enums – This enables reliable branching with logical conditions
• Add Global Nodes – Handle edge cases like user confusion or escalation requests
• Always include an End Call Node – Ensure all paths eventually terminate

In summary, Sulus Workflows give you a visual, node-based system to build predictable voice agent conversations. The combination of Conversation, API Request, Transfer, End Call, Tool, and Global nodes — connected by conditional edges — lets you model virtually any call flow. Given the upcoming retirement, treat this as reference for understanding legacy workflows rather than a starting point for new development.