Slack

Authentication Type: API Key
Description: Send and manage messages in Slack workspaces. Requires a Slack bot token (starts with xoxb-) with appropriate permissions.

Messaging

Send, schedule, and manage Slack messages.

Send Message

Send a message to a Slack channel or direct message. Supports rich formatting with blocks and attachments, threading, and various message options.

Operation Type: Mutation (Write)

Parameters:

• channel string (required): Channel ID or channel name (e.g., #general, @username, or C1234567890)
• text string (required): The main message text to send
• attachments string (nullable): JSON string of legacy structured message attachments (optional)
• blocks string (nullable): JSON string of Block Kit layout blocks (optional)
• threadTs string (nullable): Timestamp of parent message to reply in thread (optional)
• replyBroadcast boolean (nullable): Used in conjunction with thread_ts to make reply visible to everyone in channel (optional)
• unfurlLinks boolean (nullable): Pass true to enable unfurling of primarily text-based content (optional)
• unfurlMedia boolean (nullable): Pass false to disable unfurling of media content (optional)
• asUser boolean (nullable): Pass true to post the message as the authed user instead of as a bot (optional)

Returns:

• ok boolean: Whether the message was sent successfully
• channel string: The channel where the message was sent
• ts string: Timestamp of the sent message
• message object: The sent message object
  • type string: Message type
  • subtype string (nullable): Message subtype
  • text string: Message text
  • ts string: Message timestamp
  • username string (nullable): Username
  • botId string (nullable): Bot ID
  • blocks string (nullable): Message blocks
  • attachments string (nullable): Message attachments

Example Usage:

{
  "channel": "#general",
  "text": "Hello team! Here's the project update.",
  "blocks": "[{\"type\": \"section\", \"text\": {\"type\": \"mrkdwn\", \"text\": \"*Project Status:* On track\"}}]"
}

Schedule Message

Schedule a message to be sent at a specific time in the future. Perfect for reminders, announcements, or time-zone appropriate messaging.

Operation Type: Mutation (Write)

Parameters:

• channel string (required): Channel ID or channel name where message will be sent
• text string (required): The message text to schedule
• postAt number (required): Unix timestamp when the message should be sent
• attachments string (nullable): JSON string of legacy structured message attachments (optional)
• blocks string (nullable): JSON string of Block Kit layout blocks (optional)
• threadTs string (nullable): Timestamp of parent message to reply in thread (optional)
• replyBroadcast boolean (nullable): Used in conjunction with thread_ts to make reply visible to everyone in channel (optional)
• unfurlLinks boolean (nullable): Pass true to enable unfurling of primarily text-based content (optional)
• unfurlMedia boolean (nullable): Pass false to disable unfurling of media content (optional)
• asUser boolean (nullable): Pass true to post the message as the authed user instead of as a bot (optional)

Returns:

• ok boolean: Whether the message was scheduled successfully
• channel string: The channel where the message will be sent
• scheduledMessageId string: ID of the scheduled message
• postAt number: Unix timestamp when the message will be sent
• dateCreated number: Unix timestamp when the scheduled message was created

Example Usage:

{
  "channel": "#announcements",
  "text": "Daily standup starts in 15 minutes!",
  "postAt": 1672531200
}

Common Use Cases

Team Communication:

• Send project updates and announcements to channels
• Schedule reminders for meetings and deadlines
• Use threading for organized discussions

Rich Messaging:

• Format messages with Block Kit for interactive elements
• Include attachments for file sharing and media
• Control link and media unfurling behavior

Automated Workflows:

• Schedule messages for different time zones
• Post as user or bot depending on context
• Broadcast threaded replies when needed