Reactions

React to any message with built-in iMessage tapbacks or custom Unicode emoji. Reactions are an iMessage feature — see Protocol Selection for protocol capabilities. See the Reactions API Reference for the full endpoint specification.

curl -X POST https://api.linqapp.com/api/partner/v3/messages/{messageId}/reactions \
  -H "Authorization: Bearer $LINQ_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
      "operation": "add",
      "type": "love"
    }'

await client.messages.addReaction({messageId}, {
  operation: "add",
  type: "love",
});

client.messages.add_reaction(
    {message_id},
    operation="add",
    type="love",
)

client.Messages.AddReaction(context.TODO(), {messageId}, linq.MessageAddReactionParams{
  Operation: linq.F("add"),
  Type: linq.F("love"),
})

These map to the standard iMessage tapback reactions:

Send any Unicode emoji as a reaction:

curl -X POST https://api.linqapp.com/api/partner/v3/messages/{messageId}/reactions \
  -H "Authorization: Bearer $LINQ_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
      "operation": "add",
      "type": "custom",
      "custom_emoji": "😍"
    }'

await client.messages.addReaction({messageId}, {
  operation: "add",
  type: "custom",
  custom_emoji: "😍",
});

client.messages.add_reaction(
    {message_id},
    operation="add",
    type="custom",
    custom_emoji="😍",
)

client.Messages.AddReaction(context.TODO(), {messageId}, linq.MessageAddReactionParams{
  Operation: linq.F("add"),
  Type: linq.F("custom"),
  CustomEmoji: linq.F("😍"),
})

This is a tapback — the emoji sits in the small bubble at the message’s corner. To peel the same emoji onto the bubble itself as a draggable sticker, use type: "sticker" with emoji instead. See Stickers.

For messages with multiple parts, target a specific part using part_index (0-based):

curl -X POST https://api.linqapp.com/api/partner/v3/messages/{messageId}/reactions \
  -H "Authorization: Bearer $LINQ_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
      "operation": "add",
      "type": "laugh",
      "part_index": 1
    }'

await client.messages.addReaction({messageId}, {
  operation: "add",
  type: "laugh",
  part_index: 1,
});

client.messages.add_reaction(
    {message_id},
    operation="add",
    type="laugh",
    part_index=1,
)

client.Messages.AddReaction(context.TODO(), {messageId}, linq.MessageAddReactionParams{
  Operation: linq.F("add"),
  Type: linq.F("laugh"),
  PartIndex: linq.F(1),
})

If part_index is omitted, the reaction applies to the first part.

Use the same endpoint with "operation": "remove" and the matching type you originally added:

curl -X POST https://api.linqapp.com/api/partner/v3/messages/{messageId}/reactions \
  -H "Authorization: Bearer $LINQ_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
      "operation": "remove",
      "type": "like"
    }'

await client.messages.addReaction({messageId}, {
  operation: "remove",
  type: "like",
});

client.messages.add_reaction(
    {message_id},
    operation="remove",
    type="like",
)

client.Messages.AddReaction(context.TODO(), {messageId}, linq.MessageAddReactionParams{
  Operation: linq.F("remove"),
  Type: linq.F("like"),
})

Stickers are the exception — iMessage has no unpeel operation, so "operation": "remove" with type: "sticker" is rejected. See Stickers.

A sticker is an emoji or image peeled onto a message part rather than a tapback — the type is "sticker" and the payload carries image metadata.

Stickers send and receive. Peeling one onto a message uses this same endpoint with type: "sticker" and an emoji, url or attachment_id, and they can be positioned and moved afterwards — see the Stickers guide for sending, placement, and repositioning.

Inbound, they appear inside parts[].reactions[] on the message and trigger a reaction.added event:

{
  "parts": [
    {
      "type": "text",
      "value": "Hey yea",
      "reactions": [
        {
          "id": "9f8b1c2d-3e4f-5061-7283-94a5b6c7d8e9",
          "type": "sticker",
          "is_me": false,
          "custom_emoji": null,
          "sticker": {
            "file_name": "sticker-abc123.png",
            "mime_type": "image/png",
            "url": "https://cdn.linqapp.com/attachments/550e8400/sticker-abc123.png",
            "width": 320,
            "height": 320
          },
          "handle": {
            "id": "550e8400-e29b-41d4-a716-446655440011",
            "handle": "+14155559876",
            "is_me": false,
            "service": "iMessage",
            "status": "active",
            "joined_at": "2025-11-23T17:30:00.000Z",
            "left_at": null
          }
        }
      ]
    }
  ]
}

The id is what you pass to move the sticker. Stickers stack, so the message alone can’t identify one.

Webhook payloads include reaction_type, message_id, part_index, and sender information. See Reaction events for full payload details.