Automate Slack with Claude Cowork

Send channel messages, schedule announcements, share media, and streamline team communications — all from the command line or through your AI agent.

Setup Guide

Please make sure there is always a human in the loop.

Post to Slack in Seconds

Terminal

# Install the skill
npx skills add gitroomhq/postiz-agent

# Set your API key
export POSTIZ_API_KEY=your_api_key

# Find your Slack integration
postiz integrations:list

# Send a message to a Slack channel
postiz posts:create \
  -c "Team update: deployment complete" \
  --settings '{"channel":"C12345"}' \
  -i "your-slack-integration-id"

Slack-Specific Features

📢

Channel Messaging

Post messages to any Slack channel your bot has access to. Share updates, announcements, and notifications automatically.

⏰

Scheduled Messages

Schedule messages for the perfect time. Queue up announcements, reminders, and updates to post when your team is most active.

🖼

Media Sharing

Attach images, files, and rich media to your Slack messages. Share screenshots, reports, and visual updates with your team.

👥

Team Communications

Automate recurring team updates, standup summaries, and status reports across multiple channels simultaneously.

🤖

Bot Integration

Leverage Slack bot tokens for seamless posting. Your AI agent authenticates once and posts on behalf of your workspace.

📅

Multi-Channel Posting

Target different channels for different content types. Send engineering updates to #dev and marketing wins to #general.

How It Works

Find Your Slack Integration

List your connected accounts and grab your Slack integration ID. You can also fetch available settings to see what options are supported.

Discovery

# List all integrations
postiz integrations:list

# Filter for Slack
postiz integrations:list | jq \
  '.[] | select(.identifier=="slack")'

# Get Slack settings schema
postiz integrations:settings <slack-id>

Choose Your Channel

Identify the Slack channel ID where you want to post. You can find channel IDs in Slack by right-clicking a channel and selecting 'View channel details'.

Channel Setup

# Channel IDs look like C12345
# Find them in Slack:
#   Right-click channel > View channel details
#   The ID is at the bottom of the dialog

# Or use Slack's API directly
# to list channels programmatically

Create Your Post

Send a message to your Slack channel with the channel ID in settings. Schedule it for later or post immediately.

Post Creation

postiz posts:create \
  -c "Team update: deployment complete" \
  --settings '{"channel":"C12345"}' \
  -i "slack-id"

# Schedule for later
postiz posts:create \
  -c "Reminder: standup in 15 minutes" \
  -s "2025-01-15T09:45:00Z" \
  --settings '{"channel":"C12345"}' \
  -i "slack-id"

Slack Settings Reference

Every Slack post accepts these platform-specific settings via the --settings flag.

Field	Type	Required	Description
`__type`	string	Yes	Must be "slack"
`channel`	string	Yes	Slack channel ID (e.g. C12345)

Common Configurations

Copy-paste these settings for common Slack posting scenarios.

General Channel Announcement

settings.json

{
  "channel": "C12345"
}

Engineering Updates

settings.json

{
  "channel": "C67890"
}

Marketing Channel Post

settings.json

{
  "channel": "CABCDE"
}

What is Claude Cowork?

Claude Cowork is Anthropic's agentic AI tool for knowledge workers. It runs on your desktop, connects to local files and apps like Google Drive, Gmail, and DocuSign, and completes multi-step tasks autonomously.

💻

Desktop Native

Claude Cowork runs directly on your desktop, connecting to your local files and apps. No browser or cloud setup needed to manage your social media workflow.

🔗

App Integrations

Connects to Google Drive, Gmail, DocuSign, and more. Pull content from your existing tools and publish it to social media seamlessly.

🤖

Autonomous Tasks

Schedule recurring tasks with cron jobs. Claude Cowork can post your Slack messages on a schedule without you having to ask each time.

How Postiz Works with Claude Cowork

When you install Postiz Agent globally, Claude Cowork automatically discovers it by reading the bundled SKILL.md file. This file tells Claude Cowork what commands are available, what environment variables are needed, and how to compose Slack messages with the right settings.

✓Install Postiz Agent and set your POSTIZ_API_KEY
✓Claude Cowork discovers Postiz through MCP integration
✓All Postiz commands become available as tools
✓Claude Cowork autonomously chains commands for complex workflows
✓Works seamlessly with your existing desktop apps and files

Install Postiz

# Install the Postiz skill
npx skills add gitroomhq/postiz-agent

# Set your API key
export POSTIZ_API_KEY=your_api_key

# Claude Cowork discovers Postiz
# through MCP tool integration
# and can call all commands directly

Slack Posting with Claude Cowork

Tell Claude Cowork what to post from your desktop — it connects to Postiz, discovers your integrations, and handles the entire publishing workflow without you touching the terminal.

🦀

From Any Chat App

Tell Claude Cowork what to post from you...

Send a message to Claude Cowork from your favorite chat app. It runs as a persistent daemon on your machine, so it picks up your message, discovers your Slack workspace via Postiz, and sends the message to the right channel — all while you go about your day.

Claude Cowork

You: Post to Slack about our new
  feature launch, schedule for tomorrow
  at 9am

Claude Cowork: I'll handle that for you.
  1. Found your Slack integration
  2. Composing your post
  3. Scheduling for tomorrow at 9:00 AM

  Done! Your post is scheduled.
  Post ID: abc-123

🦀

Scheduled & Proactive

Claude Cowork can be asked to perfo...

Claude Cowork supports cron-based heartbeat tasks. Set up a recurring job that sends daily standup reminders or weekly status updates to your Slack channels automatically — no manual trigger needed.

Claude Cowork Task

Tell Claude Cowork:

"Every weekday morning, check my
~/content/drafts folder for new posts
and schedule them to Slack
for noon today. Move published drafts
to ~/content/published."

Claude Cowork will autonomously:
  1. Monitor your drafts folder
  2. Read and format each post
  3. Schedule via Postiz
  4. Move files when done

Why Claude Cowork + Postiz for Slack

Claude Cowork makes Postiz a natural fit for your Slack workflow. The agent discovers all available commands and autonomously chains them together.

✓Desktop-native — no terminal or CLI knowledge needed
✓Connects to your local files to pull content for Slack posts
✓Multi-step autonomy — handles discovery, composition, and scheduling
✓Works with Google Drive, Gmail, and other desktop apps
✓Cross-post to Slack + other platforms in a single request
✓Powered by Claude — Anthropic's most capable AI model

SKILL.md (auto-discovered)

---
name: postiz
description: Social media automation
  CLI for scheduling posts across
  30+ platforms including Slack
metadata:
  claude-cowork:
    requirements:
      env:
        - POSTIZ_API_KEY
      binaries:
        - postiz
---

# Available Commands
- postiz integrations:list
- postiz integrations:settings <id>
- postiz posts:create
- postiz upload <file>
- postiz analytics:platform <id>

# Slack Settings
channel (required)

Also Works with OpenClaw

Postiz Agent works as a CLI tool with any AI agent that can execute shell commands — including OpenClaw, the open-source personal AI agent.

🦀

OpenClaw

Open-source AI agent

Claude reads the SKILL.md file to learn all available Postiz commands, then autonomously discovers your Slack integration, identifies the correct channel, and sends your message.

OpenClaw

> Post a deployment update to #engineering
  on Slack

Claude will automatically run:
  postiz integrations:list
  postiz posts:create \
    -c "Deployment v2.4.1 complete" \
    --settings '{"channel":"C12345"}' \
    -i "slack-id"

Slack + Other Platforms

Post the same announcement to Slack and other platforms in a single command. Each platform gets its own settings.

Terminal

# Post an announcement to Slack and Discord simultaneously
postiz posts:create \
  -c "New feature released: dark mode is here!" \
  -s "2025-01-15T09:00:00Z" \
  --settings '{"channel":"C12345"}' \
  -i "slack-id,discord-id"

# Batch schedule a week of Slack updates
for day in 1 2 3 4 5; do
  postiz posts:create \
    -c "Daily standup reminder - Day $day" \
    -s "2025-03-0${day}T09:00:00Z" \
    --settings '{"channel":"C12345"}' \
    -i "slack-id"
done

Start posting to Slack

Install Postiz Agent and automate your Slack communications with AI-powered scheduling and messaging.

Get Started

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