mcp-slack mcp

v1.0.0 · MCP Tool · communication · registry.pascalai.org

Interact with Slack: send messages to channels or DMs, post threaded replies, upload files, add reactions, read channel history and look up users and channels.

slackmessagingchannelsnotificationschatteamalerts

Input Parameters

ParameterTypeDescription
tokenrequired string Slack Bot or User OAuth token (starts with xoxb- or xoxp-).
operationrequired string Slack operation to perform. One of: send_message, reply_thread, upload_file, add_reaction, get_history, list_channels, get_channel, list_users, get_user.
channeloptional string Channel ID or name (e.g. 'C01ABCDEF' or '#general'). Required for most operations.
textoptional string Message text. Supports Slack mrkdwn formatting (*bold*, _italic_, `code`, ```block```).
thread_tsoptional string Timestamp of parent message to reply in thread (format: '1741910400.123456').
blocksoptional array[object] Slack Block Kit blocks for rich message formatting.
file_urloptional string URL of file to upload (upload_file operation).
file_contentoptional string Text content to upload as a file (upload_file operation).
filenameoptional string Filename for uploaded file.
emojioptional string Emoji name without colons for add_reaction (e.g. 'thumbsup', 'white_check_mark').
message_tsoptional string Message timestamp for add_reaction.
limitoptional integer Max items to return for history, channels, users. Default: 20. Default: 20.

Output Fields

FieldTypeDescription
operation string
ok boolean
ts string Timestamp of the sent/affected message.
channel string
messages array[object] Channel history messages.
channels array[object] List of channels.
users array[object] List of users.
file object Uploaded file info.

Examples

Send a message to a channel

// Input
{
  "token": "xoxb-...",
  "operation": "send_message",
  "channel": "#deployments",
  "text": ":white_check_mark: *Production deploy complete*\nVersion: `v2.3.1` | Duration: `4m 12s`"
}

// Output
{
  "ok": true,
  "ts": "1741910400.123456",
  "channel": "C01ABCDEF"
}

Reply in a thread

// Input
{
  "token": "xoxb-...",
  "operation": "reply_thread",
  "channel": "C01ABCDEF",
  "thread_ts": "1741910400.123456",
  "text": "All smoke tests passed :rocket:"
}

// Output
{
  "ok": true,
  "ts": "1741910420.654321"
}

Read last messages from a channel

// Input
{
  "token": "xoxb-...",
  "operation": "get_history",
  "channel": "#general",
  "limit": 5
}

// Output
{
  "ok": true,
  "messages": [
    {
      "user": "U01ABCD",
      "text": "Hello team!",
      "ts": "1741910300.000001"
    }
  ]
}

Install & Discovery

Install

ppm install mcp-slack

Get JSON Schema

GET /v1/packages/mcp-slack/1.0.0/schema

Discover by keyword

GET /v1/mcp/discover?q=slack
Discovery hint: Install with ppm install mcp-slack or invoke remotely via POST /v1/invoke/mcp-slack on the MCP Service.

PascalAI Usage

uses toolslib;
var Tool := LoadTool('mcp-slack');
var R := Tool.Call(JsonObj([
  'token','xoxb-...',
  'operation','send_message',
  'channel','#alerts',
  'text','Batch job finished successfully'
]));
Writeln(BoolToStr(R['ok']));