Message Operations | Slack

Underlying API: chat.* and search.* Slack Web API methods.

send

Posts a message via chat.postMessage (or chat.postEphemeral when ephemeral is set).

Field	Required	Notes
`channel`	Yes	Channel ID (`C1234567890`), name (`#general`), or DM user ID (`U1234567890`).
`text`	Yes	Supports Slack `mrkdwn`: `bold`, `_italic_`, `~strike~`, `code`, `>blockquote`, `<URL\|label>`.
`threadTs`	No	Posts as a threaded reply when set.
`username`	No	Override the bot's display name for this message.
`iconEmoji`	No	Override the bot's icon with a Slack emoji (e.g. `:wave:`). Requires `chat:write.customize`.
`blocksJson`	No	Block Kit blocks as a raw JSON array string; must be a JSON array where every block has a `type` property. `text` acts as the fallback.
`ephemeral`	No	When `true`, sends via `chat.postEphemeral` instead — visible only to `targetUserId`. Ephemeral messages cannot be updated, deleted, or retrieved from history.
`targetUserId`	Conditional	Required when `ephemeral` is `true`.
`incomingText`, `conversationId`	No	Pass-through fields propagated to downstream nodes (useful when this node follows an upstream Slack event trigger).

Output: messageSent, channel, messageTs, threadTs, status, payload (raw Slack response).

sendAndWait Partial

Sends the message via chat.postMessage successfully, but then returns a NodeExecutionResult error (ENGINE_NOT_SUPPORTED) instead of suspending the workflow — workflow suspension requires ProcessEngine infrastructure that doesn't exist yet (tracked as ISSUE-04). See Roadmap.

Field	Required	Notes
`channel`	Yes	Destination channel ID.
`text`	Yes	Message text sent before waiting.
`threadTs`, `blocksJson`	No	Same semantics as `send`.
`timeoutSeconds`	No	Maximum wait before timing out. 0 or negative means wait indefinitely (engine default).
`conversationId`	No	Workflow-level conversation identifier propagated downstream.

sendEphemeral

Posts a message visible to a single user only, via chat.postEphemeral.

Field	Required	Notes
`channel`	Yes	Channel the ephemeral message appears in.
`targetUserId`	Yes	The user who will see the message.
`text`	Yes	Message text.
`threadTs`, `blocksJson`, `conversationId`	No	Same semantics as `send`.

update

Edits an existing message via chat.update. At least one of text or blocksJson must be provided.

Field	Required	Notes
`channel`	Yes	Channel containing the message.
`messageTs`	Yes	Timestamp identifying the message to edit.
`text`, `blocksJson`	At least one	New content for the message.

delete

Deletes a message via chat.delete. Requires channel and messageTs.

getPermalink

Returns a shareable link to a message via chat.getPermalink. Requires channel and messageTs.

search

Requires a user-level OAuth token (xoxp-...) with the search:read scope — bot tokens cannot call search.messages.

Field	Required	Default	Notes
`query`	Yes	—	Search query, supports Slack search modifiers (`from:`, `in:`, `before:`, etc.).
`sort`	No	Slack default (score)	Sort field.
`sortDir`	No	Slack default	Sort direction.
`returnAll`	No	`true`	Paginate through all result pages.
`count`	No	20	Results per page.
`page`	No	1	Starting page number.