TriggerSlackReal-timeUpdated June 2026

How do I trigger when a Slack reaction emoji is added?

Short answer: Drop the "Slack → Reaction Added" trigger on your workflow canvas, add filters if you want them, and publish. It fires within seconds of the event in Slack, not on a polling schedule.

Use this trigger All 13 Slack triggers

Anatomy

What this trigger looks like in a workflow.

Drop it on the canvas. Configure a couple of fields. Publish.

In the builder

Trigger

Reaction Added

When the matching event happens

new reaction addedon reaction addedwhen a reaction emoji is added to a message in slackwhen reaction addedwatch for reaction added

What this trigger returns

for the curious

You don’t need to read this. Tiny Command auto-maps every field into the visual picker so downstream nodes can pull values by clicking. We show it here for power users who want to know what’s on the wire.

{
  "raw": {
    "type": "event_callback",
    "event": {
      "item": {
        "ts": "1712835600.000100",
        "type": "message",
        "channel": "C1234567890"
      },
      "type": "reaction_added",
      "user": "U1234567890",
      "event_ts": "1712835610.000200",
      "reaction": "thumbsup",
      "item_user": "U9876543210"
    },
    "token": "verification_token",
    "team_id": "T1234567890",
    "event_id": "Ev1234567890",
    "api_app_id": "A1234567890",
    "event_time": 1712835600
  },
  "user": "U1234567890",
  "channel": "C1234567890",
  "reaction": "thumbsup",
  "item_user": "U9876543210",
  "message_ts": "1712835600.000100"
}

Output shape

Fields available to downstream nodes.

Every field below can be referenced by name in any action or filter that comes after this trigger.

Field	Type	Example
raw	object	{ … }
raw.type	string	"event_callback"
raw.event	object	{ … }
raw.event.item	object	{ … }
raw.event.item.ts	string	"1712835600.000100"
raw.event.item.type	string	"message"
raw.event.item.channel	string	"C1234567890"
raw.event.type	string	"reaction_added"
raw.event.user	string	"U1234567890"
user	string	"U1234567890"
channel	string	"C1234567890"
reaction	string	"thumbsup"
item_user	string	"U9876543210"
message_ts	string	"1712835600.000100"

Pairs with

Drop these actions after Reaction Added.

Add Labels to Message

Gmail · Email

Add Sheet Tab

Google Sheets · Spreadsheets & Databases

Create Company

HubSpot · CRM & Sales

Cancel Subscription

Stripe · Payments

FAQ

Questions about Reaction Added.

How does the Reaction Added trigger work in Slack?

Fires when a reaction emoji is added to a message in Slack. Powers reaction-driven workflows (thumbs-up to approve, fire emoji to escalate).

Is the Reaction Added trigger real-time?

Yes. Reaction Added uses webhooks or push subscriptions, not polling. Your workflow fires within seconds of the event happening in Slack.

What data does Reaction Added return?

The full event payload from Slack. The output shape table on this page lists every field, its type, and an example value so you can map fields into downstream nodes.

Can I filter Reaction Added so only some events start a workflow?

Yes. Add a Filter node right after the trigger and match on any field, whether that's subject, sender, status, or anything else in the payload. Workflows only continue when the filter passes.

Do I need Slack admin permissions to use Reaction Added?

For most Slack accounts a standard user can authorize the trigger. Some Slack plans require an admin to enable third-party webhooks. Check Slack's docs if the trigger fails to register.