Antigravity-awesome-skills slack-automation

Automate Slack workspace operations including messaging, search, channel management, and reaction workflows through Composio's Slack toolkit.

install
source · Clone the upstream repo
git clone https://github.com/sickn33/antigravity-awesome-skills
Claude Code · Install into ~/.claude/skills/
T=$(mktemp -d) && git clone --depth=1 https://github.com/sickn33/antigravity-awesome-skills "$T" && mkdir -p ~/.claude/skills && cp -r "$T/plugins/antigravity-awesome-skills/skills/slack-automation" ~/.claude/skills/sickn33-antigravity-awesome-skills-slack-automation-cea273 && rm -rf "$T"
manifest: plugins/antigravity-awesome-skills/skills/slack-automation/SKILL.md
source content

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
    <@USER_ID>
    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

TaskTool SlugKey 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.

Limitations

  • Use this skill only when the task clearly matches the scope described above.
  • Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
  • Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.