Post Ephemeral Message
slack.post_ephemeral
ActionChat & messagingconnection required
Calls the Slack Web API with the connection's bot token.
Post a message only one named user can see, which disappears on reload.
Connection
- Required
- Yes — the node will not save without one
- Auth type
- API key
- Providers
- Slack
- Secret shape
- the Slack bot token (xoxb-…), or {"token": "xoxb-…"}
- Resolved by
- config.connection_id, else node.connection_id
Configuration
5 fields, 2 required. A dotted path is a nested object and name[] an array of objects — the editor renders the same tree.
| Field | Type | Required | Default | Constraints | Example |
|---|---|---|---|---|---|
channel Channel id the message lives in (C…, or D… for a DM). Supports {{ }}. | string | Yes | — | — | — |
user The user id (U…) who will see the message. Nobody else does. | string | Yes | — | — | — |
text Message text. Also the notification fallback when blocks are present. Supports {{ }}. | string | No | — | — | — |
blocks Block Kit blocks, as a JSON array. Slack renders these instead of text. | array | No | — | array of object | — |
thread_ts Post as a reply in this thread (the parent message's ts). | string | No | — | — | — |
- At least one of text, blocks must be set.
Output
One shape.
result
| Field | Type | Example |
|---|---|---|
ok Always true; a failure raises instead. | boolean | true |
channel The channel the message was shown in. | string | — |
user The user the message was shown to. | string | — |
message_ts Slack's id for the ephemeral message. It is not a real message ts and cannot be passed to slack.update_message. | string | — |
{
"channel": "",
"message_ts": "",
"ok": true,
"user": ""
}Notes
- The bot must be a member of a private channel before it can act there (Slack answers not_in_channel otherwise).
- Slack rate-limits each Web API method on its own tier; a throttled call fails with the number of seconds to wait and is safe for the node's retry policy to repeat.
- An ephemeral message cannot be updated, deleted or reacted to afterwards.
Templates that use Slack
See Post Ephemeral Message run in a workflow.
In a technical demo we add the Slack connection, drop the node on the canvas and let Workflow Health pre-flight it before the first real run.