Action Nodes
End-call behavior, builtin functions, and pre/post agent actions.
Action capabilities fall into three categories: the End Call node (the only standalone action node on the canvas), builtin functions configured on agent nodes, and pre/post actions attached to agent nodes.
For LLM-invoked calls to your backend, see Flow Functions — a separate feature with its own structured request shape.
End Call node
The only standalone action node type. Terminate the call when the conversation reaches this node. Optionally configure a goodbye message that plays before the call disconnects.
End Call also exists as a builtin function (end_call) on agent nodes, allowing the LLM to end the call mid-conversation without requiring a separate node.
Builtin functions
Builtin functions are bot-provided primitives configured as function definitions on agent nodes. The LLM can invoke them during a conversation turn.
| Function | Description |
|---|---|
end_call | End the call. The LLM triggers this when the conversation is complete. |
end_call is the only builtin. For anything that needs to reach an external system, use flow functions. For scripted speech or call transfer that runs without LLM involvement, use pre/post actions below.
Pre/post actions
Pre/post actions execute automatically when an agent node is entered (pre) or exited (post). They run without LLM involvement.
| Action type | Config | Description |
|---|---|---|
tts_say | { text } | Speak a scripted message. Supports Handlebars template variables for dynamic content. |
play_audio | { url } | Play audio from a URL. |
wait | { durationMs } | Pause for a specified duration in milliseconds. |
webhook | { url, method } | Send an HTTP request to an external service. Fire-and-forget — result is not surfaced to the LLM. |
forward_call | { phoneNumber } | Transfer the call to another phone number. Use for escalation to a human agent, department routing, or on-call handoff. |
Pre vs post
| Hook | Fires |
|---|---|
preActions | Before the agent starts handling the turn. Typical use: announce the transfer, play hold music, log entry. |
postActions | After the agent finishes its turn or transitions away. Typical use: send a confirmation webhook, transfer the call. |
Webhook action
Fire-and-forget HTTP request. The LLM does not see the request or response. Use this for side effects — logging, notifications, CRM updates.
| Setting | Description |
|---|---|
| URL | The endpoint to call |
| Method | HTTP method (GET, POST, PUT, PATCH, DELETE) |
If you need the LLM to react to the response, use a flow function on the agent instead.