Slack — message/update

Common pattern — live status boards: Post a status message once with message/send (capturing messageTs), then update it repeatedly with message/update as the underlying state changes. This gives channel members a single, always-current message to reference rather than a stream of repetitive updates.

When to Use

Live status boards: A pinned message in #incidents tracks the current status of a service outage. As the incident progresses through "Investigating" → "Identified" → "Monitoring" → "Resolved", the workflow updates the same message in-place rather than flooding the channel with new posts.
Ticket tracker integration: When a Jira issue transitions status (e.g. from "In Progress" to "In Review"), the workflow updates the associated Slack message card to reflect the new state with a fresh timestamp.
Rolling leaderboard: A weekly sales leaderboard is posted on Monday and updated every few hours as new deals close, keeping the top-of-channel message current without creating a new post each time.
Approval status update: After an approval decision is made via message/sendAndWait, the original approval request card is updated from "Pending Approval" to "Approved ✓" or "Rejected ✗" so the channel history is accurate.
Build/deploy status: A CI/CD pipeline updates a Slack message through "Queued" → "Building" → "Testing" → "Deployed to staging" → "Deployed to production" as each pipeline stage completes.

Configuration

Connection

Field	Required	Description
`botToken`	Required	Bot Token in `xoxb-...` format. Must have `chat:write` scope and must be the same token used to originally post the message. Store in BizFirst Credentials Manager.

Operation

Field	Required	Description
`channel`	Required	Channel ID containing the message to update. Must match the channel the message was originally posted to.
`messageTs`	Required	Timestamp of the message to update (e.g. `1716700412.087200`). This is the `messageTs` returned by the original `message/send` node. Treat it as the message's unique ID.
`text`	Optional	New text content to replace the existing message text. Required if `blocksJson` is not provided.
`blocksJson`	Optional	New Block Kit blocks JSON array string. When provided, completely replaces the existing blocks. Required if `text` is not provided. Pass an empty array `[]` to remove all blocks and fall back to plain text.

At least one of text or blocksJson is required. Providing neither will result in a VAL_MISSING_CONTENT validation error. If you provide both, blocksJson is rendered and text serves as the fallback/notification text.

Sample Configuration

{
  "resource": "message",
  "operation": "update",
  "botToken": "{{ $credentials.slackBotToken }}",
  "channel": "C04INCIDENTS",
  "messageTs": "{{ $output.postIncident.messageTs }}",
  "text": "RESOLVED: payments-api incident — Service fully restored at {{ $now }}",
  "blocksJson": "[{\"type\":\"header\",\"text\":{\"type\":\"plain_text\",\"text\":\":white_check_mark: Incident Resolved\"}},{\"type\":\"section\",\"fields\":[{\"type\":\"mrkdwn\",\"text\":\"*Service:*\\n`payments-api`\"},{\"type\":\"mrkdwn\",\"text\":\"*Status:*\\n:large_green_circle: Fully Restored\"},{\"type\":\"mrkdwn\",\"text\":\"*Resolved at:*\\n{{ $now }}\"},{\"type\":\"mrkdwn\",\"text\":\"*Duration:*\\n{{ $input.incidentDurationMinutes }} minutes\"}]}]"
}

Validation Errors

Error Code	Cause
`message_not_found`	No message exists with the given `messageTs` in the specified channel. The message may have been deleted, or the timestamp is incorrect.
`cant_update_message`	The bot token is not the original sender of the message, or the message type cannot be edited (e.g. system messages, bot message subtypes with restrictions).
`channel_not_found`	The specified channel does not exist or is not accessible to the bot token.
`edit_window_closed`	Workspace admin settings restrict message editing after a certain time window. The original message is too old to edit.
`invalid_blocks`	The `blocksJson` string is malformed or references unsupported block types.
`VAL_MISSING_CHANNEL`	The `channel` field is empty or not provided.
`VAL_MISSING_TS`	The `messageTs` field is empty or not provided.
`VAL_MISSING_CONTENT`	Neither `text` nor `blocksJson` was provided. At least one is required.

Output

Success Port

Fires after Slack confirms the message has been updated. The messageTs is unchanged — the timestamp uniquely identifies the message and does not change on edit.

Field	Type	Description
`channel`	string	Channel ID where the message was updated.
`messageTs`	string	Timestamp of the updated message (same as the original — it does not change on edit).
`status`	string	`"ok"` on success.
`errorCode`	string	Empty on success.
`payload`	object	Full raw Slack API response including the updated message object.

Error Port

Fires when the message cannot be found, the bot is not the original sender, the edit window has closed, or the API call fails.

Field	Type	Description
`status`	string	`"error"`
`errorCode`	string	Slack error code, e.g. `message_not_found`, `cant_update_message`.
`payload`	object	Full raw Slack error response.

Sample Output

{
  "channel": "C04INCIDENTS",
  "messageTs": "1716700412.087200",
  "status": "ok",
  "errorCode": "",
  "payload": {
    "ok": true,
    "channel": "C04INCIDENTS",
    "ts": "1716700412.087200",
    "message": {
      "type": "message",
      "subtype": "bot_message",
      "text": "RESOLVED: payments-api incident — Service fully restored.",
      "ts": "1716700412.087200",
      "edited": {
        "user": "U0LAN0Z89",
        "ts": "1716710000.000000"
      }
    }
  }
}

Expression Reference

Field	Expression	Notes
Updated channel	`{{ $output.updateStatus.channel }}`	Resolved channel ID — confirm the update landed in the expected channel.
Message timestamp	`{{ $output.updateStatus.messageTs }}`	Same as the original `ts`. Use this for further updates or to fetch the permalink.
Operation status	`{{ $output.updateStatus.status }}`	`"ok"` on success. Check this in downstream `IfCondition` nodes.
Error code	`{{ $output.updateStatus.errorCode }}`	Non-empty if the update failed — log for monitoring.
Edit timestamp	`{{ $output.updateStatus.payload.message.edited.ts }}`	The Slack-assigned timestamp of when the edit occurred — useful for audit records.

Node Policies & GuardRails

Policy Area	Recommendation
Store the original messageTs	Always persist the `messageTs` returned by `message/send` in a workflow variable or database record. Without it, you cannot update or delete the message later. Use a `VariableAssignment` node immediately after the send.
Same token requirement	The bot token used for `message/update` must be the same token that sent the original message. Using a different token or a user token will result in `cant_update_message`.
Edit window policy	Some Slack workspace administrators enable a message edit window (e.g. only editable within 5 minutes). Design workflows that need to update messages to do so promptly after the original send. Check workspace settings if you encounter `edit_window_closed` errors.
Block replacement is complete	When providing `blocksJson`, the new array completely replaces all existing blocks. You must re-provide all blocks you wish to keep, not just the changed ones. Build the full updated Block Kit payload in your workflow before calling this node.
Error port handling	Connect the error port — especially in incident management workflows where failing to update a status message could mislead the team about the current state.
Credential storage	Store the Bot Token in BizFirst Credentials Manager. The same credential used for the original send should be referenced here.

Examples

Incident Status Update — "Resolved"

{
  "resource": "message",
  "operation": "update",
  "botToken": "{{ $credentials.slackBotToken }}",
  "channel": "C04INCIDENTS",
  "messageTs": "{{ $vars.incidentMessageTs }}",
  "text": "RESOLVED: payments-api — fully restored",
  "blocksJson": "[{\"type\":\"header\",\"text\":{\"type\":\"plain_text\",\"text\":\":white_check_mark: Incident Resolved\"}},{\"type\":\"section\",\"fields\":[{\"type\":\"mrkdwn\",\"text\":\"*Service:* `{{ $vars.serviceName }}`\"},{\"type\":\"mrkdwn\",\"text\":\"*Resolved at:* {{ $now }}\"}]}]"
}

Updates an incident card originally posted during an alert. $vars.incidentMessageTs was stored by a VariableAssignment node at incident creation time. The resolved card replaces the original alert card in-place in #incidents.

CI/CD Build Progress Tracker

{
  "resource": "message",
  "operation": "update",
  "botToken": "{{ $credentials.slackBotToken }}",
  "channel": "C04DEPLOYS01",
  "messageTs": "{{ $vars.buildMessageTs }}",
  "text": "Build #{{ $input.buildNumber }} — {{ $input.currentStage }}",
  "blocksJson": "[{\"type\":\"section\",\"text\":{\"type\":\"mrkdwn\",\"text\":\"*Build #{{ $input.buildNumber }}* — {{ $input.currentStage }}\\nCommit: `{{ $input.commitSha }}`\\nBranch: `{{ $input.branch }}`\"}},{\"type\":\"section\",\"fields\":[{\"type\":\"mrkdwn\",\"text\":\"*Test:* {{ $input.testStatus }}\"},{\"type\":\"mrkdwn\",\"text\":\"*Deploy:* {{ $input.deployStatus }}\"}]}]"
}

A CI/CD workflow posts one message per build using message/send and updates it at each stage transition using this node. Channel members see a single build card per deployment rather than a series of status messages.

Approval Card — Decision Recorded

{
  "resource": "message",
  "operation": "update",
  "botToken": "{{ $credentials.slackBotToken }}",
  "channel": "{{ $output.waitApproval.channel }}",
  "messageTs": "{{ $output.waitApproval.messageTs }}",
  "text": "PO #{{ $input.poNumber }} — {{ $output.waitApproval.replyText | upper }} by {{ $output.lookupApprover.displayName }}",
  "blocksJson": "[{\"type\":\"section\",\"text\":{\"type\":\"mrkdwn\",\"text\":\"*PO #{{ $input.poNumber }}* — :white_check_mark: *{{ $output.waitApproval.replyText | upper }}*\\nDecision by: {{ $output.lookupApprover.displayName }}\\nAt: {{ $now }}\"}}]"
}

After the message/sendAndWait node receives an approval decision, this update node edits the original approval request card to show the final decision. The card is updated from "Pending Approval" to the actual decision, providing a permanent record in the channel history.