Nodes

The six node types a flow is built from, field by field: Start Call, Prompt, Webhook, Transfer call, Redirect to Agent and End Call, and when to reach for each.

A node is one step of a flow. There are 6 types. Start Call opens the conversation, Prompt nodes carry the instructions for a stage, Webhook, Transfer call and Redirect to Agent nodes take an action, and End Call closes the conversation. Choosing a node on the canvas opens its editor in the panel on the right; the fields below are in the order the panel shows them.

Adding a node

Choose the + handle under any node. The Add node menu offers 5 types; the new node is placed below and connected with an edge whose condition you set afterwards.

In a text agent’s flow, Transfer call is greyed out with Voice agents only, and End Call reads End Conversation (End the conversation).

Every node editor ends with the same 3 buttons: Delete Node (not on Start Call), Cancel and Save Changes. Save Changes updates the canvas; the flow itself is written when you choose Save at the top of the page.

Start Call

The first node. Every flow has exactly one, and it cannot be deleted. Its editor is titled Edit Start Call Node.

The panel’s own note sums it up: the opening message is spoken first, and the conversation goal defines what the agent should accomplish during the call.

Prompt

The node for a stage of the conversation. Its editor is titled Edit Instruction Node and has 4 tabs.

General

KB

Picks the knowledge base the agent consults while at this node. Leave every box unchecked to use the agent’s default knowledge base, set with the Knowledge Base tool. Tick one or more to override it for this stage. The list is searchable, and Add KB opens the Add Resource dialog to create a text resource without leaving the flow.

Tools

Tools the agent may call while at this node.

Extract

Variables the agent fills from what the person says at this node. Each becomes a dynamic variableDynamic variableA placeholder in the prompt, such as {{customer_name}}, filled per conversation.See the glossary, written {{variable_name}}, available to every later node, webhook body and transfer message, and usable in a Variable Condition on an edge. Choose Add Variable for each one.

The tab’s header shows how many variables the node extracts, for example Extract 1.

Webhook

Calls an HTTP endpoint when the conversation reaches the node. The editor is titled Edit Function/Webhook Node. The response can be used in the nodes that follow, and an edge leaving the node can branch on Tool Result Condition, success or failure; a new edge from a Webhook node starts as Tool Result Condition with Success.

The same call is available to single-prompt agents as the Live Webhook tool; the node form is the tool form without the model-facing fields, because the node fires when reached rather than when the model decides.

Transfer call

Moves the call to a person, a queue or another number. The editor is titled Edit Transfer Call Node. Once the transfer succeeds the agent is no longer on the call.

The node covers the common case. The Transfer Call tool offers the same targets plus, for SIP trunksSIP trunkA carrier connection that brings your own phone numbers to Callab AI.See the glossary, the transfer method (blind, dial or attended), dial options such as authentication, and custom SIP headers. Use the tool as a global or node tool when you need those.

Redirect to Agent

Hands the active call to another AI agent. The editor is titled Edit Redirect to Agent Node. It is a terminal node: no further steps run in its branch.

End Call

Says a closing message and hangs up. A flow can have several End Call nodes, one per way the conversation can finish. The editor is titled Edit End Call Node.

The agent speaks the closing message, then the call terminates. A flow agent does not need the End Call tool for this; add the tool only when the agent should be able to hang up from the middle of a stage.

Related

• Flow editor
• Edges and conditions
• Dynamic variables
• Live Webhook
• Transfer Call