Schedule a message

Schedule a message

Schedules a message to post to a channel at a future Unix time and returns its scheduled message ID.

Note: Needs the chat:write scope. post_at can be at most 120 days ahead.

Set up

Use the first option your agent supports.

MCP (official, remote)

Add this server to your agent's MCP settings, then sign in when asked.

{ "mcpServers": { "slack": { "url": "https://mcp.slack.com/mcp" } } }

Call the MCP tool slack_schedule_message.

Server URL: https://mcp.slack.com/mcp

CLI (official)

Install the command, then confirm it runs.

curl -fsSL https://downloads.slack-edge.com/slack-cli/install.sh | bash
slack --version

Run slack api chat.scheduleMessage.

Set $SLACK_BOT_TOKEN in your environment first (get a key: https://api.slack.com/apps).

API (official)

• Base URL: https://slack.com/api
• Endpoint: POST /chat.scheduleMessage
• Auth: send the header Authorization: Bearer $SLACK_BOT_TOKEN
• Get a key: https://api.slack.com/apps
• Docs: https://docs.slack.dev/apis/web-api/

Before anything else, confirm access with the cheapest read-only call, like a list or a search. Never send or change anything to test access.

Rules

• Ask the user before anything that sends messages, costs money, or changes data, and say how many records it touches. One approval covers a batch the user has seen.
• Never print API keys.