> ## Documentation Index
> Fetch the complete documentation index at: https://www.voiceflow.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Custom actions

> Trace definitions, payloads, and handling guidance for custom actions.

[All traces](/docs/api-reference/trace-types)

## Custom actions

Custom action traces can be returned by functions and use the string you defined in Voiceflow as the `type` value. The `defaultPath` field indicates which path is set as the default: `0` for the first path, `1` for the second, and so on. Their payload is provided as JSON, as shown:

```json
{
  "type": "calendar",
  "time": 1720552033,
  "payload": {
    "today": 1700096585398
  },
  "defaultPath": 0,
  "paths": [
    { "event": { "type": "done" } },
    { "event": { "type": "cancel" } }
  ]
}
```