orthogonal-sh/slack

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