slack

name	slack
description	Send messages and manage Slack channels. Use when asked to send Slack messages, post to channels, list channels, or fetch message history.

Slack

Send messages, list channels, and fetch message history in Slack workspaces. Connect your Slack workspace to post messages, check channels, and retrieve conversation data.

Requirements

• Install the orth CLI
• Connect your Slack workspace at https://orthogonal.com/dashboard/integrations
• OAuth connection must be active (HTTP 428 response means not connected)

Actions

Send Message

Post a message to a Slack channel or direct message.

orth run slack /send-message --body '{
  "channel": "#general",
  "markdown_text": "Hello **team**! Check out this [link](https://example.com)."
}'

Parameters:

• channel (required) - Channel name (#general) or user ID for DM
• markdown_text (preferred) - Message content with markdown formatting
• text (deprecated) - Raw text message content
• blocks (deprecated) - Slack Block Kit formatted message
• mrkdwn - Enable markdown formatting (true/false)
• as_user - Send as authenticated user (true/false)
• username - Custom username for message
• icon_url - Custom icon URL for message
• icon_emoji - Custom emoji icon (e.g., ":ghost:")
• thread_ts - Reply to specific message thread timestamp
• link_names - Find and link channel/user names (true/false)
• attachments - Legacy message attachments
• unfurl_links - Automatically expand links (true/false)
• unfurl_media - Automatically expand media (true/false)
• reply_broadcast - Broadcast thread reply to channel (true/false)
• parse - Parse mode for text content

List Channels

Get a list of channels in your Slack workspace.

orth run slack /list-channels --body '{
  "limit": 20,
  "types": "public_channel,private_channel"
}'

Parameters:

• limit - Maximum number of channels to return
• types - Channel types to include (public_channel, private_channel, mpim, im)
• cursor - Pagination cursor
• channel_name - Filter by specific channel name
• exclude_archived - Exclude archived channels (true/false)

Fetch History

Retrieve message history from a Slack channel.

orth run slack /fetch-history --body '{
  "channel": "#general",
  "limit": 50
}'

Parameters:

• channel (required) - Channel name or ID to fetch from
• limit - Maximum number of messages to return
• cursor - Pagination cursor
• latest - Latest message timestamp to include
• oldest - Oldest message timestamp to include
• inclusive - Include messages at latest/oldest timestamps (true/false)

Usage Examples

Send formatted message:

orth run slack /send-message -b '{"channel":"#team-updates","markdown_text":"**Daily Standup Reminder**\n\nPlease share your updates in this thread!"}'

Send direct message:

orth run slack /send-message -b '{"channel":"@username","text":"Hi! Can we schedule a quick call?"}'

Reply to thread:

orth run slack /send-message -b '{"channel":"#general","text":"Thanks for the update!","thread_ts":"1234567890.123456"}'

List public channels:

orth run slack /list-channels -b '{"types":"public_channel","limit":50}'

Get recent messages:

orth run slack /fetch-history -b '{"channel":"#general","limit":10}'

Fetch messages from specific time range:

orth run slack /fetch-history -b '{"channel":"#announcements","oldest":"1640995200.000000","latest":"1641081600.000000"}'

Error Handling

• HTTP 428 - Slack integration not connected. Visit https://orthogonal.com/dashboard/integrations to connect your workspace
• 400 Bad Request - Invalid channel name or missing required parameters
• 403 Forbidden - Insufficient permissions for channel or action
• 404 Not Found - Channel does not exist or is not accessible
• 429 Rate Limited - Too many requests, wait before retrying
• channel_not_found - Specified channel does not exist
• not_in_channel - Bot is not a member of the specified channel

Tips

• Use markdown_text instead of text for formatted messages
• Channel names can be #channel-name or channel ID (C1234567890)
• For DMs, use @username or user ID (U1234567890)
• Thread timestamps are required for replying to specific messages
• Use cursor-based pagination for large channel lists
• Message timestamps are in Unix format with microsecond precision
• Bot must be invited to private channels before posting
• Some channels may require specific permissions to post or read history