# SendMessage Required Frends version: 5.7+ Required .NET version: 8.0 Compatible Agents: Unknown Source code: {% tabs %} {% tab title="Parameter: Input" %} | Name | Description | | -------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | ChannelId : `String` |

The Slack channel or user ID.

Default: -
Example: C01234567 or U12345678

| | Mode : `MessageMode` |

Message format mode.

Possible values:

PlainText:

Message format mode.

Blocks:

Message format mode.

Default: -
Example: PlainText

| | Text : `String` |

The plain text of the message to send.

Default: -
Example: Hello from our integration!

| | Blocks : `String` |

Slack Block Kit JSON for rich formatting.

Default: -
Example: \[{ "type": "section", "text": { "type": "mrkdwn", "text": "Hello world!" } }]

| | ThreadTs : `String` |

Timestamp of a message to reply in a thread.

Default: -
Example: 1234567890.123456

| | {% endtab %} | | {% tab title="Parameter: Connection" %} | Name | Description | | ------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | 🗝Token : `String` |

Slack OAuth token used for authentication.

If the token is a bot token (starts with "xoxb"), messages

will be sent as the Slack app's bot user.

If the token is a user token (starts with "xoxp"), messages

will be sent as the Slack user who authorized the token.

Note: User tokens require the user to have authorized the app via OAuth

with appropriate scopes (e.g., "chat:write").

Default: -
Example: xoxb-123456789

| | {% endtab %} | | {% tab title="Parameter: Options" %} | Name | Description | | -------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | UnfurlLinks : `Boolean` |

Whether to expand URLs in the message into rich previews (e.g. YouTube, websites).

Note: Slack may unfurl a link only once per channel to reduce duplication.

Default: True
Example: true

| | UnfurlMedia : `Boolean` |

Whether to show media previews (e.g. images, video thumbnails) for links in the message.

Note: Media previews may appear only on first post of the same link.

Default: True
Example: true

| | ThrowErrorOnFailure : `Boolean` |

True: Throw an exception.

False: Error will be added to the Result.Error.AdditionalInformation list instead of stopping the Task.

Default: True
Example: true

| | ErrorMessageOnFailure : `String` |

Message what will be used when error occurs.

Default: Failed to send message to Slack
Example: Task failed during execution

| | {% endtab %} | | {% tab title="Result: Result" %} | Name | Description | | -------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------- | | Success : `Boolean` |

Indicates whether the message was sent successfully.
Example: true

| | MessageTs : `String` |

The timestamp (ID) of the sent message.
Example: 1234567890.123456

| | Error : `Error` |

Error that occurred during task execution.
Example: object { string Message, object { Exception Exception } AdditionalInfo }

| | {% endtab %} | | {% tab title="Changelog" %} ## Changelog ### \[2.0.0] - 2026-03-04 #### Fixed * Blocks JSON string is now correctly parsed to JArray before sending to Slack API. * \[Breaking change] - Input.Blocks type changed from JArray to string. Users should now provide raw JSON string instead of parsed JArray. ### \[1.0.0] - 2025-06-03 #### Added * Initial implementation {% endtab %} {% endtabs %}