Event schemas #

The data field of a delivered webhook envelope carries a type-specific payload. The type field in the envelope tells you which schema applies:

{
  "created_at": 1712345678,
  "type": "cast.created",
  "data": { /* see below */ }
}

Hypersnap fires the following event types. Field shapes mirror common Farcaster v2 contracts so existing client models deserialize directly.

---

cast.created #

Emitted when a new cast is ingested by the node.

{
  "type": "cast.created",
  "data": {
    "cast": {
      "hash": "0x...",
      "author": { /* User */ },
      "text": "hello world",
      "timestamp": 1712345678,
      "parent_hash": null,
      "parent_url": null,
      "root_parent_url": null,
      "embeds": [],
      "mentioned_profiles": [],
      "reactions": { "likes_count": 0, "recasts_count": 0 },
      "replies": { "count": 0 }
    }
  }
}

cast.deleted #

Emitted when a cast delete message is applied.

{
  "type": "cast.deleted",
  "data": {
    "cast": { /* Same cast shape as cast.created */ }
  }
}

user.created #

Emitted on an IdRegistry register event seen on-chain. No filter fields.

{
  "type": "user.created",
  "data": {
    "user": { "fid": 12345, "username": null, "..." : "..." }
  }
}

user.updated #

Emitted when user-data (pfp, bio, display name, url, username) changes.

{
  "type": "user.updated",
  "data": {
    "user": { /* User (updated fields filled) */ }
  }
}

follow.created #

Emitted when a link_add message with type follow is applied.

{
  "type": "follow.created",
  "data": {
    "follower": { /* User */ },
    "target":   { /* User */ }
  }
}

follow.deleted #

Emitted on link_remove for a follow link.

{
  "type": "follow.deleted",
  "data": {
    "follower": { /* User */ },
    "target":   { /* User */ }
  }
}

reaction.created #

Emitted when a like or recast is applied.

{
  "type": "reaction.created",
  "data": {
    "reaction_type": "like",
    "user":  { /* User */ },
    "cast":  { /* Cast */ }
  }
}

reaction_type is either "like" or "recast".

reaction.deleted #

Same shape as reaction.created, emitted when a reaction is removed.

---

Dedupe keys #

For at-least-once delivery, dedupe on the natural key of each event type:

Event	Dedupe key
cast.created / cast.deleted	data.cast.hash
user.created	data.user.fid
user.updated	(data.user.fid, received_at) or compare fields against last-known state
follow.created / follow.deleted	(data.follower.fid, data.target.fid)
reaction.created / reaction.deleted	(data.user.fid, data.cast.hash, data.reaction_type)

Forward compatibility #

• New optional fields can appear on existing event payloads. Don't error on unknown fields.
• New event types can be added. Subscribe only to the types you know; ignore unfamiliar type values your code doesn't recognize.
• Event field semantics won't change for an existing type.