Slack Skill - Messaging & Channels Skill

Slack Skill - Messaging & Channels

Read, search, and send Slack messages. Access channels and DMs.

CRITICAL: Message Sending Confirmation Required

Before sending ANY message, you MUST get explicit user confirmation.

When the user asks to send a Slack message:

First, show them the complete message details:
- Workspace (if multiple)
- Channel/User
- Message text (or thread context if replying)
Ask: "Do you want me to send this message?"
ONLY run the send command AFTER the user explicitly confirms
NEVER send a message without this confirmation

First-Time Setup (~3 minutes)

1. Create a Slack App

Go to Slack API Apps
Click Create New App → From scratch
Name it (e.g., "Claude Assistant") and select your workspace
Click Create App

2. Add Bot Scopes

In the sidebar, click OAuth & Permissions
Scroll to Scopes → Bot Token Scopes
Add these scopes:
- channels:history - Read public channel messages
- channels:read - List public channels
- chat:write - Send messages
- groups:history - Read private channel messages
- groups:read - List private channels
- im:history - Read DM messages
- im:read - List DMs
- im:write - Send DMs
- mpim:history - Read group DM messages
- mpim:read - List group DMs
- users:read - List users
- search:read - Search messages (optional)

3. Install to Workspace

Scroll up to OAuth Tokens for Your Workspace
Click Install to Workspace
Review permissions and click Allow
Copy the Bot User OAuth Token (starts with xoxb-)

4. Save Token

Create the config file:

echo '{"default": {"token": "xoxb-YOUR-TOKEN-HERE", "workspace": "your-workspace"}}' > ~/.claude/skills/slack-skill/config.json

5. Add Bot to Channels

The bot must be invited to channels to read/send messages:

In Slack, go to the channel
Type /invite @YourBotName

Commands

List Channels

python3 ~/.claude/skills/slack-skill/slack_skill.py channels [--workspace NAME]

List Users

python3 ~/.claude/skills/slack-skill/slack_skill.py users [--workspace NAME]

Read Channel Messages

python3 ~/.claude/skills/slack-skill/slack_skill.py read CHANNEL [--limit N] [--workspace NAME]

CHANNEL can be:

Channel name: #general
Channel ID: C0XXXXXX
User for DM: @username

Send Message (Requires Confirmation)

python3 ~/.claude/skills/slack-skill/slack_skill.py send CHANNEL --message "Your message" [--thread-ts TIMESTAMP] [--workspace NAME]

Arguments:

CHANNEL - Channel name (#general), ID, or user (@username)
--message / -m - Message text (required)
--thread-ts / -t - Reply in thread (optional)
--workspace / -w - Use specific workspace

Search Messages

python3 ~/.claude/skills/slack-skill/slack_skill.py search "query" [--limit N] [--workspace NAME]

Get Thread

python3 ~/.claude/skills/slack-skill/slack_skill.py thread CHANNEL THREAD_TS [--workspace NAME]

User Info

python3 ~/.claude/skills/slack-skill/slack_skill.py user USERNAME_OR_ID [--workspace NAME]

Multi-Workspace Support

Add workspaces to ~/.claude/skills/slack-skill/config.json:

{
  "default": {
    "token": "xoxb-default-token",
    "workspace": "main-workspace"
  },
  "work": {
    "token": "xoxb-work-token",
    "workspace": "company-workspace"
  }
}

Use --workspace work to specify which workspace.

Examples

Check recent messages in #general

python3 ~/.claude/skills/slack-skill/slack_skill.py read "#general" --limit 10

Send a message to a channel

python3 ~/.claude/skills/slack-skill/slack_skill.py send "#engineering" -m "Build completed successfully!"

Reply in a thread

python3 ~/.claude/skills/slack-skill/slack_skill.py send "#general" -m "Thanks!" -t "1234567890.123456"

DM someone

python3 ~/.claude/skills/slack-skill/slack_skill.py send "@john" -m "Hey, quick question..."

Search for messages

python3 ~/.claude/skills/slack-skill/slack_skill.py search "deployment issue" --limit 20

Output

All commands output JSON for easy parsing.

Requirements

pip install slack_sdk

Security Notes

Bot tokens don't expire but can be revoked from Slack app settings
Token stored locally in ~/.claude/skills/slack-skill/config.json
Revoke access: Your Apps → Select app → Revoke All Tokens

Agent Skills: Slack Skill - Messaging & Channels

Skill Files