> ## Documentation Index
> Fetch the complete documentation index at: https://docs.b3os.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Farcaster: New Reaction

Triggers when a user reacts (like or recast) to a cast on Farcaster. Optionally filter by target FID to watch reactions to specific users' casts. Powered by Neynar webhooks.

Trigger Social

Triggers when a user reacts (like or recast) to a cast on Farcaster. Optionally filter by target FID to watch reactions to specific users' casts. Powered by Neynar webhooks.

## At a Glance

| Field | Value |
| --- | --- |
| Trigger ID | `farcaster-new-reaction` |
| Category | Social |
| Tags | `farcaster`, `social`, `reaction`, `like`, `recast`, `neynar`, `webhook` |

## Trigger Configuration

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `targetFids` | `array` | No | Filter by target Farcaster IDs \(FIDs\). Only reactions to casts by these users will trigger. |

## Trigger Result

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `triggeredAt` | `string` | Yes | Timestamp when the reaction was detected \(UTC, RFC3339 format\) |
| `eventType` | `string` | Yes | Neynar event type |
| `body` | `object` | Yes | Full Neynar reaction event data including reaction_type \(like/recast\), user \(fid, username, display_name, pfp_url\), and the target cast object |

## Workflow Root Example

```json
{
  "nodes": {
    "root": {
      "type": "farcaster-new-reaction",
      "payload": {
        "targetFids": [
          1
        ]
      },
      "children": [
        "log_event"
      ]
    },
    "log_event": {
      "type": "log",
      "payload": {
        "message": "Triggered at {{$trigger.triggeredAt}}"
      },
      "children": []
    }
  }
}
```

**Reference trigger output**

Downstream nodes can use `{{$trigger.triggeredAt}}` and any result fields listed above. Event triggers usually expose the raw source payload under a field such as `event`, `body`, `trade`, or `raw`.