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Slack

Automate Slack with Gemini CLI

Queue Slack messages from the terminal. Gemini CLI runs every postqueen command and reads the JSON back, so it can check what it scheduled.

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Quick start

Run the postqueen CLI directly, or add the MCP endpoint to your Gemini CLI settings and ask for Slack messages in plain language.

MCP supported
Terminal or settings.json
npm install -g postqueen
export POSTQUEEN_API_KEY=your_api_key
 
# Or MCP, in your Gemini CLI settings:
# { "mcpServers": { "postqueen": {
#     "url": "https://api.postqueen.ai/mcp/KEY"
# } } }

What Gemini CLI can run on Slack

Slack commands it can verify

Gemini CLI runs postqueen and reads the JSON back, so it can confirm which Slack messages exist and at what times instead of reporting success it did not check.

Windows that fit Slack

Tell Gemini CLI when your channels are busiest and it schedules messages into that window on Slack, day after day, without reminders.

The right channels, every time

Gemini CLI lists your connected channels before it posts, so messages land exactly where they should and announcements stay consistent.

Drafts until you are ready

Ask Gemini CLI for drafts only. They sit on the postqueen calendar unscheduled, so you can edit them and pick the time yourself, and nothing reaches your workspace members on Slack until you do.

Three steps to a full queue

Step 1

Discover Slack

Gemini CLI calls postqueen to list your connected channels and sees what Slack supports, so drafts start from real capabilities, not guesses.

Step 2

Draft with Gemini CLI

Give it the brief. The agent writes Slack-shaped messages and proposes publish times that match when your workspace members are around.

Step 3

Check and publish

Look over the queue on the postqueen calendar and change anything you want. postqueen publishes each post at its time, and Gemini CLI can pull the results after.

What Slack allows

Gemini CLI reads these limits from postqueen before it composes, so a draft that would be rejected never reaches the queue.

Message length
Up to 40,000 characters per message through the Slack API
Formatting
Slack mrkdwn: bold, italics, code blocks, quotes and links
File uploads
Files up to 1 GB each
Rate limit
About one message per second per channel, with short bursts allowed
App requirement
The postqueen app must be installed in the workspace and invited to private channels
Slack

Everything postqueen does on Slack

Scheduling, AI drafts, analytics and team roles, in one guide.

Read the Slack guide
F.A.Q.

Frequently asked questions

How does Gemini CLI connect Slack to postqueen?

Over MCP, registered once in Gemini CLI's own config so the Slack tools are there in every session. It also runs commands, so the CLI covers the same Slack messages when you would rather script them; both use the same API key.

Can Gemini CLI schedule Slack messages at exact times?

Yes. Give it exact slots or a rule like mornings at nine and it sets publish times on the messages it creates, keeping your channels active on a steady rhythm.

Will Gemini CLI publish to Slack on its own?

Only if you ask it to. Tell it to save drafts and nothing is scheduled: the messages wait on the calendar until you set a time. Tell it to schedule, and they go out at the times you can see, which is the setup most people move to once they trust the output.

Can one brief cover Slack and other channels too?

Yes. postqueen connects 30 channels, so Gemini CLI can turn the same brief into Slack messages plus adapted versions for every other channel you run.

Does Gemini CLI access cost extra on postqueen?

No. The agent uses your regular API key and plan limits: unlimited posts on every plan, and channel counts from 5 on Creator up to uncapped on Ultimate.

Is there a free trial for Slack scheduling?

Yes. All postqueen cloud plans include a 7-day free trial with unlimited posts, and you can cancel anytime. Self-hosting is free with the open source version.

How does postqueen connect to Slack?

Through an official Slack app with OAuth. You approve the app for your workspace, pick the channels it can post to, and every scheduled message goes out through Slack's API. Nobody shares passwords and you can revoke access from Slack at any time.

Ready to get started?

Queue this week's posts in minutes, or hand the whole thing to your favorite AI. postqueen keeps publishing either way.

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