Slack message scheduler
Schedule Slack posts with your AI agent.
Schedule messages and images to public and private Slack channels, under the name and picture you choose, with follow-ups as thread replies. Your AI agent can schedule them for you.
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Post types on Slack.
- Channel messageSent as Slack mrkdwn; long text is split into sections at line breaks
- ImagesShown under the text as image blocks
- Thread repliesFollow-ups reply in the thread, each with an optional delay
- Custom name and pictureThe name and avatar you set for the channel in PostQueen
- File uploads and videoVideo is refused before scheduling, and files are not uploaded
- Several channels in one workspaceOne channel per workspace per post
Slack limits.
| Message text | Up to 150,000 characters, sent in sections of up to 3,000 | DocsOfficial docs |
|---|---|---|
| Blocks per message | At most 50 blocks, checked before scheduling: one per 3,000 characters of text plus one per image | DocsOfficial docs |
| Image format | PNG, JPG or GIF; video is refused before scheduling | DocsOfficial docs |
| Posting rate | About 1 message per second per channel | DocsOfficial docs |
| Private channels | Invite the PostQueen app to the channel first | DocsOfficial docs |
From each network’s documentation and PostQueen’s own checks.
How to connect
- Open Add Channel and pick Slack.
- Install the PostQueen app to your workspace.
- Invite the app to any private channel you want to post in.
- In each post, pick the channel.
Settings in PostQueen
- Channel
- The public or private channel to post in. Required.
- Reply delay
- Each thread reply can wait its own delay.
From your agent
Post to Slack by asking.
Ask Grok Bot, Muse, Claude, ChatGPT or any AI agent, and the post lands on your calendar.
Good to know
- Long messages are split into sections at line breaks, up to 150,000 characters.
- Invite the PostQueen app to private channels before you schedule to them.
- Each post links to the message in Slack once it is sent.
Slack questions, answered.
Anything else? Write to support@postqueen.ai and a person answers.
Yes. Invite the PostQueen app to the private channel first, then pick it in the post. Public channels work right after you install the app.
No. Images are shown under the message as image blocks, but files are not uploaded, and a post with video is refused before it is scheduled.
The name and picture you set for the Slack channel in PostQueen, so a scheduled message can carry your brand or a team name.
Yes. Connect PostQueen to your AI agent through the MCP server or the CLI and ask it for a message with images and thread replies in a channel of your connected workspace.
Yes. Save it as a draft from Create Post, or ask your AI agent to create a draft instead of scheduling it. Drafts wait on your PostQueen calendar, and length and required settings are checked only when you schedule the post.
Anything else? Write to support@postqueen.ai and a person answers.
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Schedule from the calendar or ask your agent.Schedule from the calendar or ask your agent. Every post lands on the calendar first.
Start 7-day trial for $0$0 due today. Cancel in one click.