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Schedule messages to a Slack channel.

Connect a channel with an incoming webhook and send scheduled updates and images from PostBoost.

Free plan, no credit card. Paid plans include a 14-day free trial.

What you can post to Slack

Message

Up to 3,000 characters with up to 10 images.

Why teams schedule Slack with PostBoost

One calendar for every channel

See Slack next to your other 14 channels and move posts when plans change.

One post, a version per network

Write once, then adjust the text for Slack without copying the post.

Know when a post fails

If Slack rejects a post, you see why and can retry it once it is fixed. A webhook can tell your code too.

Your social plan, shared inside

Send the same update to Slack when it goes out on your social channels, from one post.

Connect Slack in three steps

  1. Create a Slack app

    At api.slack.com/apps create an app and turn on Incoming Webhooks.

  2. Add a webhook

    Add a webhook to the channel and copy its URL.

  3. Connect

    In PostBoost choose Connect account, then Slack, paste the URL and give the channel a name you will recognise.

PostBoost messaging channels: connect a Telegram bot, a Discord channel webhook or a Slack incoming webhook, or do it through the API

Post to Slack from your AI agent or your code

Ask your agent

“Share today's LinkedIn post in our #marketing Slack channel at 11:00.”

text MCP tools 
create-post, schedule-post

Connecting needs a webhook URL, so do it in the dashboard or with the API (connectChannel). Do not paste webhook URLs into a chat.

Set up your agent

API

bash 
curl -X POST https://postboost.co/app/api/{workspaceUuid}/accounts/connect/slack \
  -H "Authorization: Bearer YOUR_API_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"webhook_url": "https://hooks.slack.com/services/...", "name": "Marketing"}'
API reference: connectChannel
bash 
curl -X POST https://postboost.co/app/api/{workspaceUuid}/posts \
  -H "Authorization: Bearer YOUR_API_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"accounts": [12], "queue": true, "versions": [{"account_id": 0, "is_original": true, "content": [{"body": "Our API 1.8 is live."}]}]}'
API reference: createPost

Good to know

Network status: Messaging channels

Slack on PostBoost in one paragraph

PostBoost schedules and publishes to Slack: message. You connect it with an incoming webhook URL. Posts go out from the dashboard, from an AI agent over MCP or from the REST API, and each connected Slack account counts toward your plan's social accounts (Free: 3).

text 
channel: Slack
providers: slack
formats: Message
text_limit: 3,000
media: up to 10 images, sent as links to your media library; no video
connect: dashboard, or connectChannel (API)
post: create-post, schedule-post, add-post-to-queue (MCP); POST /posts createPost (API)
page: https://postboost.co/integrations/slack
docs: https://postboost.co/docs/channels/
pricing: https://postboost.co/pricing.md
llms: https://postboost.co/llms.txt

Questions about Slack

Can I delete a Slack message from PostBoost?

No. Slack incoming webhooks cannot delete messages. Delete it in Slack.

Can I send videos?

No. Slack posts can carry up to 10 images, no video.

Can I connect Slack on the Free plan?

Yes. Every plan can connect Slack. The Free plan includes 3 social accounts and 3 scheduled posts. Paid plans start at $29 a month with a 14-day free trial.

Can my AI agent post to Slack?

Yes. Connect PostBoost to Claude, ChatGPT, Cursor or another MCP client, then ask it to write or schedule a Slack post. Posts stay drafts until you or the agent schedule them.

Related

Start scheduling Slack posts today.

Free plan, no credit card.