channel/setTopic

Sets or updates the topic of a Slack channel. The topic is displayed prominently at the top of the channel and serves as a live status line. Ideal for dynamic status information that changes frequently. Requires channels:manage scope.

When to Use

Incident status updates: Set the incident channel topic with severity level, current status (investigating / mitigating / resolved), and the responsible engineer's name so all responders have instant context.
Deployment status: Update the deployment channel topic after each deploy to show the current version, environment, and deployment time (v2.4.1 deployed to prod at 14:32 UTC).
Sprint goal broadcasting: At the start of each sprint, update the team channel topic with the sprint goal and key dates so it is always visible to team members.
On-call rotation: Automatically update the ops channel topic when the on-call rotation changes to always show who is currently on-call.

Configuration

Connection

Field	Type	Required	Description
`botToken`	string	Required	Bot Token starting with `xoxb-`. Requires `channels:manage` scope.

Operation Fields

Field	Type	Required	Description
`channelId`	string	Required	The channel to update. Starts with `C` (public) or `G` (private).
`topic`	string	Required	The new topic text. Max 250 characters. Supports basic Slack formatting: `<URL\|label>`, `@user`, `#channel`.

Topic vs. Purpose: The topic is a live status line — update it frequently to reflect what is happening right now. The purpose is a stable description of what the channel is for. Use channel/setTopic for current-state information and channel/setPurpose for channel documentation.

Sample Configuration

{
  "operation": "channel/setTopic",
  "connection": {
    "botToken": "{{credentials.slackBotToken}}"
  },
  "fields": {
    "channelId": "{{$json.channelId}}",
    "topic": "{{$json.topic}}"
  }
}

Validation Errors

Error Code	Cause	Resolution
`channel_not_found`	Invalid channel ID or bot not in private channel.	Verify the channel ID. For private channels, the bot must be a member.
`missing_scope`	Bot token lacks `channels:manage` scope.	Re-authorize the Slack app with the required scope.
`is_archived`	The channel is archived.	Unarchive the channel first, then update the topic.

Output

Success Port

Field	Type	Description
`channelId`	string	The channel that was updated.
`topic`	string	The new topic text as confirmed by Slack.
`status`	string	`success` or `error`.
`errorCode`	string	Slack error code when `status` is `error`.
`payload`	object	Full raw Slack API response.

Error Port

On failure with Continue on Error enabled, routes to the error port with status: "error" and populated errorCode.

Sample Output

{
  "channelId": "C08INCIDENTS",
  "topic": "P1 ACTIVE | DB connection exhausted | Owner: @john | Status: Mitigating | Started: 14:32 UTC",
  "status": "success",
  "errorCode": "",
  "payload": {
    "ok": true,
    "topic": "P1 ACTIVE | DB connection exhausted | Owner: @john | Status: Mitigating | Started: 14:32 UTC"
  }
}

Expression Reference

Expression	Result
`{{$node["channel-settopic"].json.topic}}`	Confirmed new topic — use in audit logs.
`{{'P' + $json.severity + ' ACTIVE \| ' + $json.description + ' \| Owner: @' + $json.ownerHandle}}`	Template for an incident channel topic with severity and owner.
`{{'v' + $json.version + ' deployed to ' + $json.env + ' at ' + new Date().toUTCString()}}`	Template for a deployment status topic.
`{{'Sprint ' + $json.sprintNumber + ': ' + $json.sprintGoal + ' \| Ends: ' + $json.sprintEndDate}}`	Template for a sprint goal topic.

Node Policies & GuardRails

Policy Area	Recommendation
Scope requirements	Requires `channels:manage` scope for public channels. Private channels may need `groups:write`.
Rate limiting	Tier 2 (20+ req/min). For high-frequency topic updates (e.g., real-time status), debounce updates — send at most one update per 30 seconds to avoid flooding the channel with system messages.
No hard-coded IDs	Always source `channelId` from upstream expressions. Never hard-code channel IDs.
Topic length limit	Keep topics under 250 characters. Use a template that prioritizes the most important fields (status, owner, time) and truncates secondary details.
Topic vs. purpose	Use topic for dynamic, frequently-changing status. Use purpose for stable, descriptive documentation. Do not duplicate content between the two.
System message noise	Each topic update generates a system message in the channel ("Bot updated the channel topic"). For high-frequency updates, consider batching changes to reduce noise.

Examples

Example 1 — Incident Channel Topic with Live Status

When an incident fires or its status changes, updates the incident channel topic with current severity, status, and owner.

// Triggered by PagerDuty status change event
// $json.severity, $json.description, $json.ownerHandle, $json.status, $json.startedAt

{
  "operation": "channel/setTopic",
  "fields": {
    "channelId": "{{$json.incidentChannelId}}",
    "topic": "{{
      $json.severity + ' ' + $json.status.toUpperCase() +
      ' | ' + $json.description.substring(0, 80) +
      ' | Owner: @' + $json.ownerHandle +
      ' | Started: ' + $json.startedAt
    }}"
  }
}

Example 2 — Deployment Channel Post-Deploy Update

After a successful deployment pipeline completes, updates the deploy channel topic to reflect the current production version.

// Triggered by CI/CD pipeline success event
// $json.version, $json.environment, $json.deployedBy

{
  "operation": "channel/setTopic",
  "fields": {
    "channelId": "C08DEPLOYS01",
    "topic": "{{
      'PROD: v' + $json.version +
      ' | Deployed: ' + new Date().toUTCString() +
      ' | By: ' + $json.deployedBy
    }}"
  }
}

Example 3 — Weekly On-Call Rotation Update

Scheduled Monday morning workflow that updates the ops channel topic with the week's on-call engineer.

// HTTP Request → get on-call schedule for this week
// $json.oncallName, $json.oncallHandle, $json.weekEndDate

{
  "operation": "channel/setTopic",
  "fields": {
    "channelId": "C08OPSALERTS",
    "topic": "{{
      'On-call this week: @' + $json.oncallHandle +
      ' (' + $json.oncallName + ')' +
      ' | Rotation ends: ' + $json.weekEndDate +
      ' | PagerDuty: https://pagerduty.example.com/oncall'
    }}"
  }
}