Subagent Node

Have a conversation with the user while allowing the agent to call tools and functions during the conversation.

Subagent node is used to have a conversation with the user while allowing the agent to call tools / functions during the conversation. Use it when the agent should decide whether and when to use a tool / function based on the conversation context.

If you only need dialogue without tool calling, use a Conversation Node instead.

How It Works

When a subagent node has tools / functions attached, the LLM receives both the node instruction and the list of available tools / functions. During the conversation, the LLM determines when a tool / function should be called based on context, extracts the required parameters, and invokes it while maintaining the dialogue with the user.

• Multiple tools / functions can be added to a single subagent node
• The agent can continue talking while a tool / function executes
• Tool / function results are available to the LLM for generating follow-up responses

Write Instruction

Subagent nodes only support Prompt instructions. Static Sentence is not supported.

Write the instruction to define the task, what information the agent should gather, and when it should use the available tools / functions.

Help the user check their order status. If the user provides an order number,
use the available order lookup tool to retrieve the latest status.

Subagent Node vs Function Node

	Function Node	Subagent Node
Execution	Deterministic — executes on node entry	LLM-driven — called when LLM decides it’s appropriate
Tools per node	One	Multiple
Conversation	Not intended for dialogue	Full dialogue with tools available
Best for	Always-execute actions (e.g. always look up order on entry)	Context-dependent actions during dialogue (e.g. look up only if user asks)

Add Tools / Functions

1. Select a subagent node

   Click on a subagent node to open its settings panel on the right side.

2. Add a tool / function

   In the settings panel, find the Tools section and click + Add. Select the tool / function type from the dropdown.

3. Configure the tool / function

   Configure based on its type. See the Available Tool / Function Types table below.

4. Update the node instruction

   Update the node prompt to guide the LLM on when to use each tool / function.

Available Tool / Function Types

Tool Type	Description
Custom Function	Make HTTP requests to your external APIs
Code Tool	Run JavaScript code directly without an external server
Check Calendar Availability	Query available time slots via Cal.com
Book Appointment	Book calendar events via Cal.com
End Call	Terminate the call
Transfer Call	Transfer to a phone number
Transfer Agent	Transfer to another agent
Press Digit	Send DTMF tones
Send SMS	Send a text message
Extract Dynamic Variable	Extract variables from the conversation
MCP Tool	Call tools on your MCP server

Execution Speech Settings

Speak During Execution

When enabled, the agent says a message while the tool / function is executing (e.g. “One moment, let me check that for you.”). Recommended when the tool / function takes over 1 second including network latency.

Configure how the message is generated:

• Prompt: LLM dynamically generates what to say based on a description you provide
• Static Sentence: Agent speaks the exact text you provide

Speak After Execution

When enabled, the agent calls the LLM after the tool / function returns a result so it can speak about the outcome. Turn this off to run the tool silently.

• Speak During Execution available on: Custom Function, Code Tool, End Call, Transfer Call, Transfer Agent, MCP Tool
• Speak After Execution available on: Custom Function, Code Tool, MCP Tool

When Can Transition Happen

• When user is done speaking
• When Skip Response is enabled and agent finishes speaking

Tool / function execution happens within the subagent node, so the node can stay active across multiple turns and tool / function calls before it transitions.

Node Settings

Setting	Description
Tools	Attach the tools / functions this subagent can use during the conversation.
Skip Response	When enabled, only one outgoing edge is allowed. Agent transitions via that edge when done talking.
Knowledge Base	Configure node-level knowledge bases to combine with the agent-level knowledge base.
Global Node	See Global Node guide.
Block Interruptions	When enabled, agent will not be interrupted by user when speaking.
LLM	Choose a different model — used for response generation, tool selection, and argument generation.
Fine-tuning Examples	Fine-tune conversation response and transition. See Finetune Examples guide.

Best Practices

• Be explicit in your node instruction — tell the agent when each tool / function should be used
• Use function nodes for guaranteed execution — if a tool must always run at a certain point, use a function node instead
• Avoid adding too many tools to one subagent node — if you have many tools, consider splitting them across multiple subagent nodes