Send Slack
Step · Stable
Post a message to a Slack channel or thread via the connected Slack integration.
Sends a message to Slack via chat.postMessage. channel is a channel name (#alerts) or id (C0123ABCD); text is the message body. Optionally pass thread_ts (the ts of an earlier Slack message) to thread replies under it — capture {{ <earlier_label>.ts }} and feed it here to keep a flow’s messages in one thread. Falls back to the integration’s default channel when channel is omitted. Requires Slack connected under Settings → Integrations.
When to use
Section titled “When to use”Use to inform a person or channel from any trigger — a new lead landed, a production batch finished, a loading-bay issue was raised. channel and text both accept a {{ reference }} to upstream values.
When not to use
Section titled “When not to use”For email delivery use Send email; for in-app alerts use Send notification. To ask a Slack user a question and wait for a button/text answer, use Ask a person with channel: slack — not this fire-and-forget send. If Slack is not connected the step fails with a clear error.
Inputs
Section titled “Inputs”channel
Section titled “channel”string · optional
Channel name (#alerts) or id (C0123ABCD). Defaults to the integration default channel.
string · required
Templates ({{ refs }}) resolve against the run context. With format_markdown on, a GFM pipe table (header row, then a |---|---:| separator row setting alignment) becomes a native Slack table block instead of literal pipe characters; a bare ---/***/___ line becomes a divider; a standalone line becomes an inline image (must be https — a non-https URL is left as literal text). Tables over 100 rows / 20 columns / 10,000 characters exceed Slack’s own caps and fall back to literal text too — keep summary tables, not full data dumps.
Example: | Item | Amount | |---|---:| | Widget A | 1450.50 | --- Approved by {{ user.firstName }}.
- ✓
| Item | Amount | |---|---:| | Widget A | 1450.50 |— a GFM pipe table renders as a real Slack table - ✓
Deploy finished. --- Next run: {{ next_run }}— --- on its own line renders as a section divider - ✗
Item Amount -------- ------- Widget A 1450.50— space-padded ASCII columns are not a GFM table — ships as literal misaligned text, use | pipes instead
thread_ts
Section titled “thread_ts”string · optional
Optional: ts of an earlier Slack message to thread under.
format_markdown
Section titled “format_markdown”bool · optional
Convert standard Markdown in the message (# headings, bold, - bullets, text) into Slack mrkdwn before sending. Tables, --- dividers, and standalone lines render as native Slack blocks instead of literal text. Turn on when the text is authored as ordinary Markdown; leave off if it is already Slack-formatted or plain text.
Outputs
Section titled “Outputs”Requires
Section titled “Requires”the slack integration
Auto-generated from the skill registry (load_skills()). Do not edit by hand.