link_shared event

The link_shared event is sent over the Events API when a link—matching the registered URL domain your app is setup to track—is posted.

Your app will receive this event both when the link is written into the message composer before being posted, and when the link is posted into a Slack channel.

The link_shared event is dispatched when a message posted includes a matching domain, with the exception of messages posted by classic apps. Apps will also not receive link_shared events for their own messages. Refer to Quickstart: differences between classic apps and Slack apps for more information.

For context on these events, learn more about unfurling links in messages.

{
    "token": "XXYYZZ",
    "team_id": "T123ABC456",
    "api_app_id": "A123ABC456",
    "event": {
        "type": "link_shared",
        "channel": "C123ABC456",
        "is_bot_user_member": true,
        "user": "U123ABC456",
        "message_ts": "123456789.9875",
        "unfurl_id": "C123456.123456789.987501.1b90fa1278528ce6e2f6c5c2bfa1abc9a41d57d02b29d173f40399c9ffdecf4b",
        "thread_ts": "123456621.1855",
        "source": "conversations_history",
        "links": [
            {
                "domain": "example.com",
                "url": "https://example.com/12345"
            },
            {
                "domain": "example.com",
                "url": "https://example.com/67890"
            },
            {
                "domain": "another-example.com",
                "url": "https://yet.another-example.com/v/abcde"
            }
        ]
    },
    "type": "event_callback",
    "authed_users": [
        "U123ABC456",
        "U222222222"
    ],
    "event_id": "Ev123ABC456",
    "event_time": 123456789
}

The thread_ts field only appears when the link was shared within a message thread.

is_bot_user_member is a boolean field indicating whether the app’s bot user is a member of the conversation.

unfurl_id identifies the link and can be used to supply the chat.unfurl method (along with source).

source is an enumerated string that tells you whether the event happened in composer ("source": "composer") or in a sent message ("source": "conversations_history).

Take care with the message_ts and channel fields. When the source of this event is the message composer, rather than a posted message, these values don't correspond to typical timestamps and channels. No matter what, the values of message_ts and channel always work to supply chat.unfurl, but if you attempt to use other Slack API methods with these timestamps and channels, the calls will fail.

A full payload for the link_shared event sent when a link is typed into the message composer is:

{
    "type": "link_shared",
    "channel": "COMPOSER",
    "is_bot_user_member": true,
    "user": "U123ABC456",
    "message_ts": "U123ABC456-909b5454-75f8-4ac4-b325-1b40e230bbd8-gryl3kb80b3wm49ihzoo35fyqoq08n2y",
    "unfurl_id": "U123ABC456-909b5454-75f8-4ac4-b325-1b40e230bbd8-gryl3kb80b3wm49ihzoo35fyqoq08n2y",
    "source": "composer",
    "links": [
        {
            "domain": "example.com",
            "url": "https://example.com/12345"
        },
        {
            "domain": "example.com",
            "url": "https://example.com/67890"
        },
        {
            "domain": "another-example.com",
            "url": "https://yet.another-example.com/v/abcde"
        }
    ]
}

Learn more about unfurling links in messages.