Model Context Protocol (MCP) server for Slack Workspaces. The most powerful MCP Slack server — supports Stdio and SSE transports, proxy settings, DMs, Group DMs, Smart History fetch (by date or count), may work via OAuth or in complete stealth mode with no permissions and scopes in Workspace 😏.
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This feature-rich Slack MCP Server has:
#Name @Lookup: Fetch messages from channels and threads, including activity messages, and retrieve channels using their names (e.g., #general) as well as their IDs.conversations_add_message tool is disabled by default for safety. Enable it via an environment variable, with optional channel restrictions.Get messages from the channel (or DM) by channel_id, the last row/column in the response is used as 'cursor' parameter for pagination if not empty
channel_id (string, required): - channel_id (string): ID of the channel in format Cxxxxxxxxxx or its name starting with #... or @... aka #general or @username_dm.include_activity_messages (boolean, default: false): If true, the response will include activity messages such as channel_join or channel_leave. Default is boolean false.cursor (string, optional): Cursor for pagination. Use the value of the last row and column in the response as next_cursor field returned from the previous request.limit (string, default: "1d"): Limit of messages to fetch in format of maximum ranges of time (e.g. 1d - 1 day, 1w - 1 week, 30d - 30 days, 90d - 90 days which is a default limit for free tier history) or number of messages (e.g. 50). Must be empty when 'cursor' is provided.Get a thread of messages posted to a conversation by channelID and thread_ts, the last row/column in the response is used as cursor parameter for pagination if not empty.
channel_id (string, required): ID of the channel in format Cxxxxxxxxxx or its name starting with #... or @... aka #general or @username_dm.thread_ts (string, required): Unique identifier of either a thread’s parent message or a message in the thread. ts must be the timestamp in format 1234567890.123456 of an existing message with 0 or more replies.include_activity_messages (boolean, default: false): If true, the response will include activity messages such as 'channel_join' or 'channel_leave'. Default is boolean false.cursor (string, optional): Cursor for pagination. Use the value of the last row and column in the response as next_cursor field returned from the previous request.limit (string, default: "1d"): Limit of messages to fetch in format of maximum ranges of time (e.g. 1d - 1 day, 1w - 1 week, 30d - 30 days, 90d - 90 days which is a default limit for free tier history) or number of messages (e.g. 50). Must be empty when 'cursor' is provided.Add a message to a public channel, private channel, or direct message (DM, or IM) conversation by channel_id and thread_ts.
Note: Posting messages is disabled by default for safety. To enable, set the
SLACK_MCP_ADD_MESSAGE_TOOLenvironment variable. If set to a comma-separated list of channel IDs, posting is enabled only for those specific channels. See the Environment Variables section below for details.
channel_id (string, required): ID of the channel in format Cxxxxxxxxxx or its name starting with #... or @... aka #general or @username_dm.thread_ts (string, optional): Unique identifier of either a thread’s parent message or a message in the thread_ts must be the timestamp in format 1234567890.123456 of an existing message with 0 or more replies. Optional, if not provided the message will be added to the channel itself, otherwise it will be added to the thread.payload (string, required): Message payload in specified content_type format. Example: 'Hello, world!' for text/plain or '# Hello, world!' for text/markdown.content_type (string, default: "text/markdown"): Content type of the message. Default is 'text/markdown'. Allowed values: 'text/markdown', 'text/plain'.Search messages in a public channel, private channel, or direct message (DM, or IM) conversation using filters. All filters are optional, if not provided then search_query is required.
search_query (string, optional): Search query to filter messages. Example: 'marketing report' or full URL of Slack message e.g. 'https://slack.com/archives/C1234567890/p1234567890123456', then the tool will return a single message matching given URL, herewith all other parameters will be ignored.filter_in_channel (string, optional): Filter messages in a specific channel by its ID or name. Example: C1234567890 or #general. If not provided, all channels will be searched.filter_in_im_or_mpim (string, optional): Filter messages in a direct message (DM) or multi-person direct message (MPIM) conversation by its ID or name. Example: D1234567890 or @username_dm. If not provided, all DMs and MPIMs will be searched.filter_users_with (string, optional): Filter messages with a specific user by their ID or display name in threads and DMs. Example: U1234567890 or @username. If not provided, all threads and DMs will be searched.filter_users_from (string, optional): Filter messages from a specific user by their ID or display name. Example: U1234567890 or @username. If not provided, all users will be searched.filter_date_before (string, optional): Filter messages sent before a specific date in format YYYY-MM-DD. Example: 2023-10-01, July, Yesterday or Today. If not provided, all dates will be searched.filter_date_after (string, optional): Filter messages sent after a specific date in format YYYY-MM-DD. Example: 2023-10-01, July, Yesterday or Today. If not provided, all dates will be searched.filter_date_on (string, optional): Filter messages sent on a specific date in format YYYY-MM-DD. Example: 2023-10-01, July, Yesterday or Today. If not provided, all dates will be searched.filter_date_during (string, optional): Filter messages sent during a specific period in format YYYY-MM-DD. Example: July, Yesterday or Today. If not provided, all dates will be searched.filter_threads_only (boolean, default: false): If true, the response will include only messages from threads. Default is boolean false.cursor (string, default: ""): Cursor for pagination. Use the value of the last row and column in the response as next_cursor field returned from the previous request.limit (number, default: 20): The maximum number of items to return. Must be an integer between 1 and 100.Get list of channels
channel_types (string, required): Comma-separated channel types. Allowed values: mpim, im, public_channel, private_channel. Example: public_channel,private_channel,imsort (string, optional): Type of sorting. Allowed values: popularity - sort by number of members/participants in each channel.limit (number, default: 100): The maximum number of items to return. Must be an integer between 1 and 1000 (maximum 999).cursor (string, optional): Cursor for pagination. Use the value of the last row and column in the response as next_cursor field returned from the previous request.The Slack MCP Server exposes two special directory resources for easy access to workspace metadata:
1.slack://<workspace>/channels — Directory of Channels
Fetches a CSV directory of all channels in the workspace, including public channels, private channels, DMs, and group DMs.
slack://<workspace>/channelstext/csvid: Channel ID (e.g., C1234567890)name: Channel name (e.g., #general, @username_dm)topic: Channel topic (if any)purpose: Channel purpose/descriptionmemberCount: Number of members in the channelslack://<workspace>/users — Directory of Users
Fetches a CSV directory of all users in the workspace.
slack://<workspace>/userstext/csvuserID: User ID (e.g., U1234567890)userName: Slack username (e.g., john)realName: User’s real name (e.g., John Doe)SLACK_MCP_XOXC_TOKEN Yes* nil Slack browser token (xoxc-...) SLACK_MCP_XOXD_TOKEN Yes* nil Slack browser cookie d (xoxd-...) SLACK_MCP_XOXP_TOKEN Yes* nil User OAuth token (xoxp-...) — alternative to xoxc/xoxd SLACK_MCP_PORT No 13080 Port for the MCP server to listen on SLACK_MCP_HOST No 127.0.0.1 Host for the MCP server to listen on SLACK_MCP_SSE_API_KEY No nil Bearer token for SSE transport SLACK_MCP_PROXY No nil Proxy URL for outgoing requests SLACK_MCP_USER_AGENT No nil Custom User-Agent (for Enterprise Slack environments) SLACK_MCP_CUSTOM_TLS No nil Send custom TLS-handshake to Slack servers based on SLACK_MCP_USER_AGENT or default User-Agent. (for Enterprise Slack environments) SLACK_MCP_SERVER_CA No nil Path to CA certificate SLACK_MCP_SERVER_CA_TOOLKIT No nil Inject HTTPToolkit CA certificate to root trust-store for MitM debugging SLACK_MCP_SERVER_CA_INSECURE No false Trust all insecure requests (NOT RECOMMENDED) SLACK_MCP_ADD_MESSAGE_TOOL No nil Enable message posting via conversations_add_message by setting it to true for all channels, a comma-separated list of channel IDs to whitelist specific channels, or use ! before a channel ID to allow all except specified ones, while an empty value disables posting by default. SLACK_MCP_ADD_MESSAGE_MARK No nil When the conversations_add_message tool is enabled, any new message sent will automatically be marked as read. SLACK_MCP_ADD_MESSAGE_UNFURLING No nil Enable to let Slack unfurl posted links or set comma-separated list of domains e.g. github.com,slack.com to whitelist unfurling only for them. If text contains whitelisted and unknown domain unfurling will be disabled for security reasons. SLACK_MCP_USERS_CACHE No .users_cache.json Path to the users cache file. Used to cache Slack user information to avoid repeated API calls on startup. SLACK_MCP_CHANNELS_CACHE No .channels_cache_v2.json Path to the channels cache file. Used to cache Slack channel information to avoid repeated API calls on startup. SLACK_MCP_LOG_LEVEL No info Log-level for stdout or stderr. Valid values are: debug, info, warn, error, panic and fatal
*You need either xoxp or both xoxc/xoxd tokens for authentication.
channels_list will be fully not functional. Tools conversations_* will have limited capabilities and you won't be able to search messages by @userHandle or #channel-name, getting messages by @userHandle or #channel-name won't be available either. ✅ ❌ No channels cache, tool channels_list will be fully not functional. Tools conversations_* will have limited capabilities and you won't be able to search messages by @userHandle or #channel-name, getting messages by @userHandle or #channel-name won't be available either. ✅ ✅ No limitations, fully functional Slack MCP Server.
# Run the inspector with stdio transport npx @modelcontextprotocol/inspector go run mcp/mcp-server.go --transport stdio # View logs tail -n 20 -f ~/Library/Logs/Claude/mcp*.log
Licensed under MIT - see LICENSE file. This is not an official Slack product.
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