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Slack Writer

Send messages to Slack channels and users through the Slack API.

Slack Writer Node

Quick Start

  1. Create a Slack App and install it to your workspace
  2. Copy your Bot User OAuth Token (starts with xoxb-)
  3. Add the Slack Writer node to your workflow
  4. Paste your token and specify a channel (e.g., #general)
  5. Send a test message

Setup Guide

1. Create a Slack App

  1. Go to Slack API Apps page
  2. Click "Create New App" → "From scratch"
  3. Name your app and select your workspace

2. Configure Bot Permissions

  1. Navigate to "OAuth & Permissions"
  2. Add these Bot Token Scopes:
  3. chat:write - Send messages
  4. chat:write.customize - Customize bot name/icon
  5. channels:read - View channels
  6. groups:read - View private channels

3. Install & Configure

  1. Click "Install to Workspace" and authorize
  2. Copy the "Bot User OAuth Token"
  3. In Slack, invite bot to channels with /invite @YourBotName

Basic Usage

Simple Message

{
  "channel": "#general",
  "message": "Hello team! Important meeting at 2 PM."
}

Thread Reply

{
  "channel": "#general",
  "message": "Here are the meeting notes.",
  "thread_timestamp": "1680123456.789000"
}

Rich Message with Block Kit

[
  {
    "type": "header",
    "text": {
      "type": "plain_text",
      "text": "🚨 System Alert",
      "emoji": true
    }
  },
  {
    "type": "section",
    "text": {
      "type": "mrkdwn",
      "text": "*Database Backup Complete*\nAll systems operating normally."
    }
  }
]

Configuration

Required Inputs

Field Description Type Example
Slack Token Bot User OAuth Token Password xoxb-1234567890-abcdefg-hijklmnop
Channel Channel or user to message String #general or @username
Message Text content (if not using Block Kit) String Hello team!

Optional Inputs

Field Description Type Example
Block Kit JSON Rich message formatting JSON See examples below
Icon Emoji Bot icon emoji String :robot:
Icon URL Bot icon image URL String https://example.com/icon.png
Thread Timestamp Reply to thread String 1680123456.789000

Outputs

Field Description Example
Status API call status ok
Thread Timestamp Message timestamp 1680123456.789000
Response Full API response See below

Best Practices

Message Design

  • Keep messages concise and well-structured
  • Use Block Kit for complex layouts
  • Include clear call-to-actions

Threading

  • Use threads to organize conversations
  • Save timestamps for follow-ups
  • Avoid deep nesting

Performance & Security

  • Store tokens securely
  • Batch messages when possible
  • Monitor rate limits

Troubleshooting

Common Issues

  • Message Not Sent: Check token and channel permissions
  • Invalid Token: Ensure token starts with xoxb-
  • Channel Not Found: Verify channel exists and bot is invited

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