Help Centre › Functions & Formulas
This article describes the RPA Slack connector function to send a message.
For a full list of available functions, please read SLACK functions.
Description
The Send message function posts a message to a Slack channel. Supports plain text, threading (replies), and rich formatting via Block Kit blocks.
Setting it up
{{popups:rpas/add:action=slack-send-message}}
Once on a process map:
- Navigate to the process where you would like to add the function
- Click on the green button’s drop-down (right side of the green button labelled “Process”)
- On the menu that appears, click on the “+ Activity” item
- From here you can select the SLACK Send message option
- Click "Add" once you are done
Input parameters
| Parameter | Required | Type | Default | Description |
|---|---|---|---|---|
| Connector | Yes | Select | - | Select the Slack connector to use |
| Channel | Yes | Text | - | Channel ID (e.g. C0123456) – use List channels to find |
| Text | Yes | Textarea | - | Message text (supports Slack markdown: *bold*, _italic_, `code`) |
| Thread | No | Text | - | Thread timestamp to reply in a thread |
| Blocks | No | Textarea | - | Block Kit blocks as JSON for rich formatting |
| Variable | Yes | Text | - | Variable to store the result |
Output variables
| Variable | Type | Description |
|---|---|---|
| Variable | Object | API response with ok, channel, ts (message timestamp), and message object |
Errors
- channel_not_found – the channel ID is invalid or the bot is not in the channel
- not_authed – the bot token is invalid
- too_many_attachments – message exceeds Block Kit limits
Tips
- Use List channels to find channel IDs (they look like C0123456)
- To reply in a thread, pass the parent message’s ts as the Thread parameter
- Use variables in the text: "Invoice {invoice_number} processed successfully"
- Save the {variable.ts} to later update or reply to the message
Related functions
- Update message – Edit a sent message
- Add reaction – React to a message
- Upload file – Share a file in a channel