Reaction Messages

Apply emoji reactions to WhatsApp user messages. Limitations (sent-only status, 30-day window, error 131009), how to remove a reaction, and inbound user reaction webhooks.

What Reaction Messages Do

Reaction messages let you apply an emoji to a message you've received from a WhatsApp user — the same single-emoji reaction users apply natively in WhatsApp. They're sent through the standard /messages endpoint with type: "reaction" and reference the original user message by its WhatsApp message ID (wamid).

Reactions are a service message type and require an open customer service window.

Limitations

Only sent status webhooks fire for reactions — no delivered and no read webhooks. Treat acceptance by Cloud API as the deliverable signal.
You can only react to a message you have received — not to your own outbound messages.
If the target message is more than 30 days old, has been deleted, doesn't correspond to any message in the chat thread, or is itself a reaction, your reaction won't be delivered. You receive a messages webhook with error code 131009.
One reaction per message. Sending a new reaction on the same message replaces the existing one.
Multi-character emoji (skin-tone modifiers, ZWJ sequences) are supported but a single reaction is one emoji.

Send a Reaction

{
  "messaging_product": "whatsapp",
  "recipient_type": "individual",
  "to": "12015550123",
  "type": "reaction",
  "reaction": {
    "message_id": "wamid.HBgLMTY0NjcwNDM1OTUVAgASGBQzQUZCMTY0MDc2MUYwNzBDNTY5MAA=",
    "emoji": "😀"
  }
}

Two equivalent ways to specify the emoji:

Form	Example	Notes
Unicode escape sequence	`"😀"`	Safe for any transport (no encoding gotchas)
Literal emoji	`"😀"`	Requires UTF-8 throughout your serialization

Use whichever your stack handles cleanly. If you're constructing the JSON in a language that doesn't escape correctly by default, prefer the escape sequence.

message_id is the wamid of the user's message you're reacting to. You'll have received it on the inbound messages webhook.

Remove a Reaction

Send the same payload with emoji set to an empty string:

{
  "messaging_product": "whatsapp",
  "to": "12015550123",
  "type": "reaction",
  "reaction": {
    "message_id": "wamid.HBgL...",
    "emoji": ""
  }
}

This removes any reaction you previously placed on that message.

Inbound User Reactions

When a user reacts to one of your outbound messages, you receive a messages webhook with type: "reaction":

{
  "messages": [
    {
      "from": "12015550123",
      "id": "wamid.HBgL...",
      "timestamp": "1702920965",
      "type": "reaction",
      "reaction": {
        "message_id": "wamid.HBgL...",
        "emoji": "👍"
      }
    }
  ]
}

reaction.message_id references your original message. reaction.emoji is the chosen emoji (literal, not escape sequence). When the user removes their reaction, you receive a similar webhook with emoji set to an empty string.

In Dualhook setups this webhook arrives on the messages field and is delivered directly to your endpoint via Webhook Override — Dualhook does not ingest it.

Use Cases

Acknowledge a user message without composing a full reply (👍 / ✅).
Signal a message has been actioned (📦 for "shipped", 💸 for "refunded").
Disambiguate "I saw this" from "I'm working on it" without the typing-indicator/read-receipt nuance.

Reactions never substitute for a real reply on transactional issues — use them to cut noise on quick acknowledgements, not to avoid sending a status update the user is waiting for.

Service MessagesFree-form messages sent inside an open customer service window: type list, contextual replies, media caching, TTL, message quality, and pricing.
Messaging WebhookReal-time webhook events for inbound messages, delivery statuses, and errors.