ActionSlackUpdated May 2026

How do I post a Slack message to a channel?

Short answer: Drop the "Slack → Send Message" action anywhere in your workflow, map the inputs from upstream nodes, and publish.

Use this action All 45 Slack actions

Inputs

The fields this action accepts.

Every field can be mapped from an upstream trigger, AI step, table row, or hard-coded literal.

Field	Type	Required	Description
Channel channel	string	Required	Channel ID or name (e.g. #general or C1234567890). Channel ID is more reliable.
Message Text text	string	Required	Message text to post. Supports Slack mrkdwn (e.g. bold, <@U123> mentions, <#C123> channel links).
Thread Timestamp thread_ts	string	Optional	To reply in a thread, provide the parent message's timestamp (ts)
Unfurl Links unfurl_links	options	Optional	Whether to show link previews

Sample request

{
  "channel": "e.g. C1234567890 or #general",
  "text": "e.g. Hello team! :wave: Here's the daily update...",
  "thread_ts": "e.g. 1234567890.123456",
  "unfurl_links": "{{trigger.unfurl_links}}"
}

Returns

{
  "ok": true,
  "ts": "1700000000.000100",
  "channel": "C1234567890",
  "message": {
    "ts": "1700000000.000100",
    "text": "Hello team!",
    "type": "message"
  }
}

Use these fields in downstream nodes for routing, logging, or error handling.

Triggered by

Apps that pair well as the trigger for Send Message.

Any of these apps can fire this action as part of a workflow.

Gmail → Slack

1 Gmail triggers

Google Sheets → Slack

2 Google Sheets triggers

FAQ

Questions about Send Message.

What does the Send Message action do in Slack?

Posts a message to a Slack channel with optional blocks, attachments, and thread_ts (to reply in a thread). The default notification action.

What inputs does Send Message require?

Required: Channel, Message Text. Every input accepts a static value or a variable from any upstream node in your workflow.

Can I use dynamic inputs from earlier workflow nodes?

Yes. Any field on this action can pull values from upstream nodes, whether that's a form response, a trigger payload, an AI output, or a lookup result.

What happens if Slack returns an error?

The workflow pauses on the failed node, the error message is captured in the run log, and you can retry the run with one click. Auto-retry policies are configurable per workflow with exponential backoff up to 5 attempts.

Does Send Message support batch operations?

Yes. Run Send Message inside a Loop node to process arrays. Tiny Command handles Slack's rate limits automatically so you don't have to throttle manually.

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