Slack

Type ID: slack  ·  Kind: Action  ·  Trace: TOOL

Send messages to Slack channels, groups, and direct messages via the Slack Web API.

Credentials

Slack

Resources & operations

• Message (message)
  • Send (send) — Send a message to a channel, group, or user.

Properties

Common

Property	Key	Type	Required	Default	Possible values	Shown when
Resource	resource	options	Yes	message	Message (message)	—
Operation	operation	options	Yes	send	Send (send)	resource = message

Message → Send

Property	Key	Type	Required	Default	Possible values	Shown when
Channel/User	channel	string	Yes	''	Channel name (e.g. #general), channel ID (e.g. C1234567890), or user ID (e.g. U1234567890)	resource = message, operation = send
Message Text	text	string	Yes	''	Free text; supports markdown, @mentions, :emojis:, links (<url|text>)	resource = message, operation = send
Advanced Message Options	additionalFields	object	No	{}	Collection (see below)	resource = message, operation = send

additionalFields collection options:

Property	Key	Type	Required	Default	Possible values
Thread Timestamp	thread_ts	string	No	''	Parent message ts value to reply in-thread
Use Markdown	mrkdwn	boolean	No	true	true / false
Link Names	link_names	boolean	No	true	true / false
Unfurl Links	unfurl_links	boolean	No	true	true / false
Unfurl Media	unfurl_media	boolean	No	true	true / false

Notes

• Requires a Slack credential; the credential ID is read from credentials.id and resolved to a bearer token. A missing credential ID or token raises an error before any request.
• Calls POST https://slack.com/api/chat.postMessage with Authorization: Bearer <token>.
• channel and text are validated as non-empty at runtime; either being missing throws Channel and message text are required.
• Optional fields (thread_ts, mrkdwn, link_names, unfurl_links, unfurl_media) are only added to the request body when present.
• Slack returns HTTP 200 even on failure; the handler inspects the ok field and throws Slack API error: <error> when ok is false.
• Output JSON: { success: true, channel, timestamp, message: { text, ts, user, bot_id, bot_name, thread_ts } }.