Slack Automation

# Slack Automation via Rube MCP Automate Slack workspace operations including messaging, search, channel management, and reaction workflows through Composio's Slack toolkit. ## Prerequisites - Rube MCP must be connected (RUBE_SEARCH_TOOLS available) - Active Slack connection via `RUBE_MANAGE_CONNECTIONS` with toolkit `slack` - Always call `RUBE_SEARCH_TOOLS` first to get current tool schemas ## Setup **Get Rube MCP**: Add `https://rube.app/mcp` as an MCP server in your client configuration. No API keys needed — just add the endpoint and it works. 1. Verify Rube MCP is available by confirming `RUBE_SEARCH_TOOLS` responds 2. Call `RUBE_MANAGE_CONNECTIONS` with toolkit `slack` 3. If connection is not ACTIVE, follow the returned auth link to complete Slack OAuth 4. Confirm connection status shows ACTIVE before running any workflows ## Core Workflows ### 1. Send Messages to Channels **When to use**: User wants to post a message to a Slack channel or DM **Tool sequence**: 1. `SLACK_FIND_CHANNELS` - Resolve channel name to channel ID [Prerequisite] 2. `SLACK_LIST_ALL_CHANNELS` - Fallback if FIND_CHANNELS returns empty/ambiguous results [Fallback] 3. `SLACK_FIND_USERS` - Resolve user for DMs or @mentions [Optional] 4. `SLACK_OPEN_DM` - Open/reuse a DM channel if messaging a user directly [Optional] 5. `SLACK_SEND_MESSAGE` - Post the message with resolved channel ID [Required] 6. `SLACK_UPDATES_A_SLACK_MESSAGE` - Edit the posted message if corrections needed [Optional] **Key parameters**: - `channel`: Channel ID or name (without '#' prefix) - `markdown_text`: Preferred field for formatted messages (supports headers, bold, italic, code blocks) - `text`: Raw text fallback (deprecated in favor of markdown_text) - `thread_ts`: Timestamp of parent message to reply in a thread - `blocks`: Block Kit layout blocks (deprecated, use markdown_text) **Pitfalls**: - `SLACK_FIND_CHANNELS` requires `query` param; missing it errors with "Invalid request data provided" - `SLACK_SEND_MESSAGE` requires valid channel plus one of markdown_text/text/blocks/attachments - Invalid block payloads return error=invalid_blocks (max 50 blocks) - Replies become top-level posts if `thread_ts` is omitted - Persist `response.data.channel` and `response.data.message.ts` from SEND_MESSAGE for edit/thread operations ### 2. Search Messages and Conversations **When to use**: User wants to find specific messages across the workspace **Tool sequence**: 1. `SLACK_FIND_CHANNELS` - Resolve channel for scoped search with `in:#channel` [Optional] 2. `SLACK_FIND_USERS` - Resolve user for author filter with `from:@user` [Optional] 3. `SLACK_SEARCH_MESSAGES` - Run keyword search across accessible conversations [Required] 4. `SLACK_FETCH_MESSAGE_THREAD_FROM_A_CONVERSATION` - Expand threads for relevant hits [Required] **Key parameters**: - `query`: Search string supporting modifiers (`in:#channel`, `from:@user`, `before:YYYY-MM-DD`, `after:YYYY-MM-DD`, `has:link`, `has:file`) - `count`: Results per page (max 100), or total with auto_paginate=true - `sort`: 'score' (relevance) or 'timestamp' (chronological) - `sort_dir`: 'asc' or 'desc' **Pitfalls**: - Validation fails if `query` is missing/empty - `ok=true` can still mean no hits (`response.data.messages.total=0`) - Matches are under `response.data.messages.matches` (sometimes also `response.data_preview.messages.matches`) - `match.text` may be empty/truncated; key info can appear in `matches[].attachments[]` - Thread expansion via FETCH_MESSAGE_THREAD can truncate when `response.data.has_more=true`; paginate via `response_metadata.next_cursor` ### 3. Manage Channels and Users **When to use**: User wants to list channels, users, or workspace info **Tool sequence**: 1. `SLACK_FETCH_TEAM_INFO` - Validate connectivity and get workspace identity [Required] 2. `SLACK_LIST_ALL_CHANNELS` - Enumerate public channels [Required] 3. `SLACK_LIST_CONVERSATIONS` - Include private channels and DMs [Optional] 4. `SLACK_LIST_ALL_USERS` - List workspace members [Required] 5. `SLACK_RETRIEVE_CONVERSATION_INFORMATION` - Get detailed channel metadata [Optional] 6. `SLACK_LIST_USER_GROUPS_FOR_TEAM_WITH_OPTIONS` - List user groups [Optional] **Key parameters**: - `cursor`: Pagination cursor from `response_metadata.next_cursor` - `limit`: Results per page (default varies; set explicitly for large workspaces) - `types`: Channel types filter ('public_channel', 'private_channel', 'im', 'mpim') **Pitfalls**: - Workspace metadata is nested under `response.data.team`, not top-level - `SLACK_LIST_ALL_CHANNELS` returns public channels only; use `SLACK_LIST_CONVERSATIONS` for private/IM coverage - `SLACK_LIST_ALL_USERS` can hit HTTP 429 rate limits; honor Retry-After header - Always paginate via `response_metadata.next_cursor` until empty; de-duplicate by `id` ### 4. React to and Thread Messages **When to use**: User wants to add reactions or manage threaded conversations **Tool sequence**: 1. `SLACK_SEARCH_MESSAGES` or `SLACK_FETCH_CONVERSATION_HISTORY` - Find the target message [Prerequisite] 2. `SLACK_ADD_REACTION_TO_AN_ITEM` - Add an emoji reaction [Required] 3. `SLACK_FETCH_ITEM_REACTIONS` - List reactions on a message [Optional] 4. `SLACK_REMOVE_REACTION_FROM_ITEM` - Remove a reaction [Optional] 5. `SLACK_SEND_MESSAGE` - Reply in thread using `thread_ts` [Optional] 6. `SLACK_FETCH_MESSAGE_THREAD_FROM_A_CONVERSATION` - Read full thread [Optional] **Key parameters**: - `channel`: Channel ID where the message lives - `timestamp` / `ts`: Message timestamp (unique identifier like '1234567890.123456') - `name`: Emoji name without colons (e.g., 'thumbsup', 'wave::skin-tone-3') - `thread_ts`: Parent message timestamp for threaded replies **Pitfalls**: - Reactions require exact channel ID + message timestamp pair - Emoji names use Slack's naming convention without colons - `SLACK_FETCH_CONVERSATION_HISTORY` only returns main channel timeline, NOT threaded replies - Use `SLACK_FETCH_MESSAGE_THREAD_FROM_A_CONVERSATION` with parent's `thread_ts` to get thread replies ### 5. Schedule Messages **When to use**: User wants to schedule a message for future delivery **Tool sequence**: 1. `SLACK_FIND_CHANNELS` - Resolve channel ID [Prerequisite] 2. `SLACK_SCHEDULE_MESSAGE` - Schedule the message with `post_at` timestamp [Required] **Key parameters**: - `channel`: Resolved channel ID - `post_at`: Unix timestamp for delivery (up to 120 days in advance) - `text` / `blocks`: Message content **Pitfalls**: - Scheduling is limited to 120 days in advance - `post_at` must be a Unix timestamp, not ISO 8601 ## Common Patterns ### ID Resolution Always resolve display names to IDs before operations: - **Channel name -> Channel ID**: `SLACK_FIND_CHANNELS` with `query` param - **User name -> User ID**: `SLACK_FIND_USERS` with `search_query` or `email` - **DM channel**: `SLACK_OPEN_DM` with resolved user IDs ### Pagination Most list endpoints use cursor-based pagination: - Follow `response_metadata.next_cursor` until empty - Set explicit `limit` values (e.g., 100-200) for reliable paging - De-duplicate results by `id` across pages ### Message Formatting - Prefer `markdown_text` over `text` or `blocks` for formatted messages - Use `` format to mention users (not @username) - Use `n` for line breaks in markdown_text ## Known Pitfalls - **Channel resolution**: `SLACK_FIND_CHANNELS` can return empty results if channel is private and bot hasn't been invited - **Rate limits**: `SLACK_LIST_ALL_USERS` and other list endpoints can hit HTTP 429; honor Retry-After header - **Nested responses**: Results may be nested under `response.data.results[0].response.data` in wrapped executions - **Thread vs channel**: `SLACK_FETCH_CONVERSATION_HISTORY` returns main timeline only; use `SLACK_FETCH_MESSAGE_THREAD_FROM_A_CONVERSATION` for thread replies - **Message editing**: Requires both `channel` and original message `ts`; persist these from SEND_MESSAGE response - **Search delays**: Recently posted messages may not appear in search results immediately - **Scope limitations**: Missing OAuth scopes can cause 403 errors; check with `SLACK_GET_APP_PERMISSION_SCOPES` ## Quick Reference | Task | Tool Slug | Key Params | |------|-----------|------------| | Find channels | `SLACK_FIND_CHANNELS` | `query` | | List all channels | `SLACK_LIST_ALL_CHANNELS` | `limit`, `cursor`, `types` | | Send message | `SLACK_SEND_MESSAGE` | `channel`, `markdown_text` | | Edit message | `SLACK_UPDATES_A_SLACK_MESSAGE` | `channel`, `ts`, `markdown_text` | | Search messages | `SLACK_SEARCH_MESSAGES` | `query`, `count`, `sort` | | Get thread | `SLACK_FETCH_MESSAGE_THREAD_FROM_A_CONVERSATION` | `channel`, `ts` | | Add reaction | `SLACK_ADD_REACTION_TO_AN_ITEM` | `channel`, `name`, `timestamp` | | Find users | `SLACK_FIND_USERS` | `search_query` or `email` | | List users | `SLACK_LIST_ALL_USERS` | `limit`, `cursor` | | Open DM | `SLACK_OPEN_DM` | user IDs | | Schedule message | `SLACK_SCHEDULE_MESSAGE` | `channel`, `post_at`, `text` | | Get channel info | `SLACK_RETRIEVE_CONVERSATION_INFORMATION` | channel ID | | Channel history | `SLACK_FETCH_CONVERSATION_HISTORY` | `channel`, `oldest`, `latest` | | Workspace info | `SLACK_FETCH_TEAM_INFO` | (none) | ## When to Use This skill is applicable to execute the workflow or actions described in the overview.