/slack-bot

name: slack-bot
description: >
  Send messages and rich content to Slack channels via webhooks or Bot API. Use Block Kit for
  formatted announcements, marketing reports, and community updates. Trigger phrases:
  "post to slack", "slack message", "slack webhook", "slack notification", "slack announcement",
  "send to slack", "slack marketing", "slack update", "slack channel".
allowed-tools:
  - Bash
  - WebFetch
  - WebSearch

Slack Bot

Send messages and rich content to Slack channels using Incoming Webhooks or the Slack Web API. Build formatted announcements, marketing reports, metrics dashboards, and community updates with Block Kit.

Prerequisites

Requires either `SLACK_WEBHOOK_URL` or `SLACK_BOT_TOKEN` set in `.env`, `.env.local`, or `~/.claude/.env.global`.

source ~/.claude/.env.global 2>/dev/null
source .env 2>/dev/null
source .env.local 2>/dev/null

if [ -n "$SLACK_WEBHOOK_URL" ]; then
  echo "SLACK_WEBHOOK_URL is set. Webhook mode available."
elif [ -n "$SLACK_BOT_TOKEN" ]; then
  echo "SLACK_BOT_TOKEN is set. Web API mode available."
else
  echo "Neither SLACK_WEBHOOK_URL nor SLACK_BOT_TOKEN is set."
  echo "See the Setup Guide below to configure Slack credentials."
fi

If neither variable is set, instruct the user to follow the Setup Guide section below.

---

Setup Guide

Option A: Incoming Webhook (Simple)

Incoming Webhooks are the fastest way to post messages. They require no OAuth scopes and are scoped to a single channel.

1. Go to https://api.slack.com/apps and click **Create New App** > **From scratch**. 2. Name the app (e.g., "Marketing Bot") and select your workspace. 3. In the left sidebar, click **Incoming Webhooks** and toggle it **On**. 4. Click **Add New Webhook to Workspace** at the bottom. 5. Select the channel to post to and click **Allow**. 6. Copy the Webhook URL (starts with `https://hooks.slack.com/services/...`). 7. Add it to your environment:

echo 'SLACK_WEBHOOK_URL=https://hooks.slack.com/services/T.../B.../xxxx' >> .env

**Limitations:** One webhook per channel. Cannot read messages, list channels, or reply to threads programmatically (you must know the `thread_ts` from a prior API response).

Option B: Bot Token (Full Featured)

Bot tokens give access to the full Slack Web API: post to any channel the bot is in, reply to threads, list channels, upload files, and more.

1. Go to https://api.slack.com/apps and click **Create New App** > **From scratch**. 2. Name the app and select your workspace. 3. In the left sidebar, click **OAuth & Permissions**. 4. Under **Bot Token Scopes**, add these scopes:

• `chat:write` - Post messages
• `chat:write.public` - Post to channels without joining
• `channels:read` - List public channels
• `files:write` - Upload files (optional, for images/reports)
• `reactions:write` - Add emoji reactions (optional)

5. Click **Install to Workspace** at the top and authorize. 6. Copy the **Bot User OAuth Token** (starts with `xoxb-`). 7. Add it to your environment:

echo 'SLACK_BOT_TOKEN=xoxb-your-token-here' >> .env

8. Invite the bot to the channels it should post in: type `/invite @YourBotName` in each channel.

**Optional:** Set a default channel for convenience:

echo 'SLACK_DEFAULT_CHANNEL=#marketing' >> .env

---

Method 1: Incoming Webhooks

Send a Simple Text Message

curl -s -X POST "$SLACK_WEBHOOK_URL" \
  -H "Content-Type: application/json" \
  -d '{
    "text": "Hello from the marketing bot!"
  }'

Send a Message with Username and Icon Override

curl -s -X POST "$SLACK_WEBHOOK_URL" \
  -H "Content-Type: application/json" \
  -d '{
    "text": "New blog post published!",
    "username": "Marketing Bot",
    "icon_emoji": ":mega:"
  }'

Send a Message with Block Kit (Webhook)

curl -s -X POST "$SLACK_WEBHOOK_URL" \
  -H "Content-Type: application/json" \
  -d '{
    "blocks": [
      {
        "type": "header",
        "text": {
          "type": "plain_text",
          "text": "New Product Launch"
        }
      },
      {
        "type": "section",
        "text": {
          "type": "mrkdwn",
          "text": "*Product X* is now live! Check out the announcement."
        }
      },
      {
        "type": "divider"
      },
      {
        "type": "section",
        "text": {
          "type": "mrkdwn",
          "text": "Read the full announcement on our blog."
        },
        "accessory": {
          "type": "button",
          "text": {
            "type": "plain_text",
            "text": "Read More"
          },
          "url": "https://example.com/blog/launch"
        }
      }
    ]
  }'

---

Method 2: Slack Web API (Bot Token)

The Web API provides full control over message delivery, threading, channel management, and more.

API Base

All requests go to `https://slack.com/api/` with the header `Authorization: Bearer {SLACK_BOT_TOKEN}`.

Post a Message to a Channel

curl -s -X POST "https://slack.com/api/chat.postMessage" \
  -H "Authorization: Bearer ${SLACK_BOT_TOKEN}" \
  -H "Content-Type: application/json" \
  -d '{
    "channel": "#marketing",
    "text": "Weekly metrics report is ready!",
    "blocks": [
      {
        "type": "header",
        "text": {
          "type": "plain_text",
          "text": "Weekly Marketing Metrics"
        }
      },
      {
        "type": "section",
        "text": {
          "type": "mrkdwn",
          "text": "Here are the numbers for this week."
        }
      }
    ]
  }'

The response includes a `ts` (timestamp) field which identifies the message. Save this value for threading replies:

# Post and capture the message timestamp for threading
RESPONSE=$(curl -s -X POST "https://slack.com/api/chat.postMessage" \
  -H "Authorization: Bearer ${SLACK_BOT_TOKEN}" \
  -H "Content-Type: application/json" \
  -d '{
    "channel": "#marketing",
    "text": "Thread parent message"
  }')

MESSAGE_TS=$