slack_add_reaction
Add an emoji reaction to a message
LABSCO SUMMARY
Slack in your agent with no Slack app, admin request or OAuth ticket.
It acts as your own signed-in identity and cannot read a channel you cannot read, which is exactly why setup is one command instead of a request to IT. The cost is the session model itself: credentials rotate, and Enterprise Grid runs session-anomaly detection that can flag and kill a session — outbound calls are paced to stay under burst thresholds, and Grid users are pointed at OAuth instead.
What it is
A local server that reuses the Slack session already in Chrome rather than asking an admin to install a Slack app. It reads DMs, channels, threads and search results with user names resolved, and can reply, react and mark conversations read as you.
What you get
- Conversations with unread messages, ranked by unread count, so a morning catch-up starts where it should
- Channel and DM history with user names resolved, and blocks, attachments, files, reactions and metadata when text alone is not the message
- A whole conversation exported with all of its threads, optionally written to a file
- Workspace message search, plus user lookup and user search by name, display name or email
- Replies sent, reactions added or removed, conversations marked read — every write carries an MCP destructive annotation so the client can ask first
- Credential state on demand: token age, storage backend, cache stats, and a refresh straight from the browser session on macOS
- Workflow profiles saved locally, binding a kind — support_inbox, incident_room, exec_brief, product_launch_watch or custom — to channels, priority people and a cadence
- On the hosted tier: a structured catch-up per profile, thread triage with priority and suggested owner, and hybrid semantic search over indexed history
Requirements
Node 22 or 24 is recommended and Node 20 still works. On macOS, npx -y @jtalk22/slack-mcp --setup lifts the session out of Chrome — the token from its LevelDB, the cookie from its SQLite store, decrypted locally against the Keychain — and transmits nothing. On other platforms you supply SLACK_TOKEN and SLACK_COOKIE from that session yourself. Those credentials rotate, commonly after a week or two; slack_refresh_tokens or a second --setup recovers them. SLACK_MCP_PROFILE keeps work and personal workspaces separate, and SLACK_MCP_TOOLS=essentials advertises six tools rather than the full set when schema size per turn matters. slack_catch_me_up, slack_triage and slack_smart_search run on the hosted OAuth tier at mcp.revasserlabs.com, whose free plan covers 25 AI tool calls a month.
Setup effort
One command — npx -y @jtalk22/slack-mcp --setup
USE CASES
01
Finding out what blew up overnight
Pull the conversations carrying unread messages, ranked by count, then read the threads that matter with names already resolved.
02
Answering without opening Slack
Reply in the thread, add the reaction, and mark the conversation read — each write is annotated so the client can gate it.
03
Digging out something someone said months ago
Search the workspace, then export the full conversation with its threads to a file you can keep.
04
Handing an on-call shift over
Save a workflow profile for the incident room, then run the catch-up against it for a timeline, open risks and owner gaps.
05
Checking the connection is still alive
Verify credentials and workspace identity, and refresh them from the browser session when Slack starts rejecting them.
06
Working out who to ask about something
Search users by name, display name or email, then read the profile behind the match.
21 tools
Counted once with only startup setup. Other versions, modes or optional credentials may expose a different list.
slack_catch_me_up
Run a structured catch-up against a saved workflow profile. Returns structured JSON per the profile's workflow_kind: support_inbox returns {open_threads, ack_lag, owner_gaps, escalations, next_actions}; incident_room returns {incident_summary, timeline, open_risks, owner_gaps, next_actions}; exec_brief returns {summary, decisions, risks, asks, action_items}; product_launch_watch returns {launch_signals, feedback_themes, blockers, metrics, next_actions}; custom returns {summary, highlights, open_questions, next_actions}. Hosted-only. Free tier ships 25 AI tool calls/month (shared across the hosted AI tools); Pro $19/mo unlocks unlimited.
slack_conversations_history
Get messages from a channel or DM with user names resolved
slack_conversations_mark
Mark a conversation as read up to a specific message timestamp
slack_conversations_unreads
Get channels and DMs with unread messages, sorted by unread count (highest first)
slack_get_full_conversation
Export FULL conversation history with all messages, threads, and user names. Can save to file.
slack_get_thread
Get all replies in a message thread
slack_health_check
Check if Slack tokens are valid and show authentication status
slack_list_conversations
List all DMs and channels with user names resolved. Uses cached DMs by default for speed.
slack_list_users
List all users in the workspace
slack_refresh_tokens
Force refresh tokens by extracting from Chrome (requires Slack tab open in Chrome)
slack_remove_reaction
Remove an emoji reaction from a message
slack_search_messages
Search messages across the Slack workspace
slack_send_message
Send a message to a channel or DM
slack_smart_search
Semantic + lexical hybrid search across your indexed Slack history. Returns ranked results with relevance scores, channel context, thread context, and matched terms. Hosted-only (requires Vectorize + Workers AI). Free tier ships 25 AI tool calls/month (shared across the hosted AI tools); upgrade to Pro $19/mo for unlimited at mcp.revasserlabs.com/pricing.
slack_token_status
Check token health, age, auto-refresh status, and cache stats
slack_triage
Classify and route Slack threads against a workflow profile. Returns triage decisions per thread: priority (low|medium|high|urgent), suggested owner, escalation flag, time-sensitivity, and a routing recommendation. Hosted-only. Free tier ships 25 AI tool calls/month (shared across the hosted AI tools); Pro $19/mo unlocks unlimited.
slack_users_info
Get detailed information about a Slack user
slack_users_search
Search workspace users by name, display name, or email. Case-insensitive partial match.
slack_workflow_save
Save or update a workflow profile that binds a workflow_kind (support_inbox | incident_room | exec_brief | product_launch_watch | custom) to channels, priority people, retention mode, and summary cadence. Stored locally at ~/.slack-mcp-workflows.json. Hosted brain reads these to return structured JSON per the workflow_kind.
slack_workflows
List all saved workflow profiles from ~/.slack-mcp-workflows.json. Optionally filter by workflow_kind. Returns profile_name, channels, priority_people, retention_mode, summary_cadence, structured_keys, created_at, updated_at.
BEFORE YOU INSTALL
What to know first
Tools you get
21 tools when we connected. slack_smart_search, slack_catch_me_up and slack_triage are hosted-only and return a tool_requires_hosted stub in the open-source build. SLACK_MCP_TOOLS=essentials advertises six and =read the twelve read-only tools.
Requires
- npx on PATH
- Node 20 or newer (22 or 24 recommended)
Optional
- SLACK_TOKEN in your environment
- SLACK_COOKIE in your environment
CONTEXT COST
Light Standing cost
Rated by the size of the 21 tool definitions that ride along on every turn, not by how many there are
INSTALLATION
Connect your client
Server setup
TERMINAL
npx -y @jtalk22/slack-mcp --setupMCP Clients
Any MCP client — npx
ANY MCP CLIENT — NPX · JSON
{
"mcpServers": {
"slack-mcp-server": {
"command": "npx",
"args": [
"-y",
"@jtalk22/slack-mcp"
]
}
}
}The configuration on this page does not set SLACK_TOKEN, SLACK_COOKIE.
Claude Code
CLAUDE CODE · TERMINAL
claude mcp add slack -- npx -y @jtalk22/slack-mcpClaude Desktop, Cursor, Windsurf, Gemini CLI
JSON
{
"mcpServers": {
"slack": {
"command": "npx",
"args": [
"-y",
"@jtalk22/slack-mcp"
]
}
}
}The configuration on this page does not set SLACK_TOKEN, SLACK_COOKIE.
GitHub Copilot — VS Code MCP JSON
GITHUB COPILOT — VS CODE MCP JSON · JSON
{
"servers": {
"slack": {
"command": "npx",
"args": [
"-y",
"@jtalk22/slack-mcp"
]
}
}
}The configuration on this page does not set SLACK_TOKEN, SLACK_COOKIE.
Codex
CODEX · TERMINAL
codex mcp add slack -- npx -y @jtalk22/slack-mcpAny MCP client — two workspaces
ANY MCP CLIENT — TWO WORKSPACES · JSON
{
"mcpServers": {
"slack-work": {
"command": "npx",
"args": [
"-y",
"@jtalk22/slack-mcp"
],
"env": {
"SLACK_MCP_PROFILE": "work"
}
},
"slack-personal": {
"command": "npx",
"args": [
"-y",
"@jtalk22/slack-mcp"
],
"env": {
"SLACK_MCP_PROFILE": "personal"
}
}
}
}The configuration on this page does not set SLACK_TOKEN, SLACK_COOKIE.
Any MCP client — global install
ANY MCP CLIENT — GLOBAL INSTALL · TERMINAL
npm install -g @jtalk22/slack-mcp
slack-mcp --setup
