Slack

SlackTools enable an Agent to interact with the Slack API. 12 methods cover messaging, channels, file management, search, threads, and user lookup.

Prerequisites

1uv pip install -U "kern-ai[slack]"

1export SLACK_TOKEN=***

Example

The following agent sends a message to a Slack channel, lists channels, and retrieves message history.

1import os
2
3from kern.agent import Agent
4from kern.tools.slack import SlackTools
5
6slack_tools = SlackTools()
7
8agent = Agent(tools=[slack_tools])
9
10# Example 1: Send a message to a Slack channel
11agent.print_response("Send a message 'Hello from Kern!' to the channel #general", markdown=True)
12
13# Example 2: List all channels in the Slack workspace
14agent.print_response("List all channels in our Slack workspace", markdown=True)
15
16# Example 3: Get the message history of a specific channel by channel ID
17agent.print_response("Get the last 10 messages from the channel 1231241", markdown=True)

Toolkit Params

Parameter	Type	Default	Description
`token`	`Optional[str]`	`None`	Slack API token. Falls back to `SLACK_TOKEN` env var.
`markdown`	`bool`	`True`	Enable Slack mrkdwn formatting in messages.
`output_directory`	`Optional[str]`	`None`	Directory to save downloaded/uploaded files locally.
`enable_send_message`	`bool`	`True`	Enable `send_message` tool.
`enable_send_message_thread`	`bool`	`True`	Enable `send_message_thread` tool.
`enable_list_channels`	`bool`	`True`	Enable `list_channels` tool.
`enable_get_channel_history`	`bool`	`True`	Enable `get_channel_history` tool.
`enable_upload_file`	`bool`	`True`	Enable `upload_file` tool.
`enable_download_file`	`bool`	`True`	Enable `download_file` tool.
`enable_search_messages`	`bool`	`False`	Enable `search_messages` tool. Requires a user token and the `search:read` OAuth scope.
`enable_search_workspace`	`bool`	`False`	Enable `search_workspace` tool. Uses Slack's `assistant.search.context` API. Requires `search:read.public`, `search:read.files`, and `search:read.users` bot scopes. Only works through the Slack interface (needs `action_token`).
`enable_get_thread`	`bool`	`False`	Enable `get_thread` tool.
`enable_list_users`	`bool`	`False`	Enable `list_users` tool.
`enable_get_user_info`	`bool`	`False`	Enable `get_user_info` tool.
`enable_get_channel_info`	`bool`	`False`	Enable `get_channel_info` tool.
`all`	`bool`	`False`	Enable all tools. Overrides individual flags.
`ssl`	`Optional[SSLContext]`	`None`	SSL context for the Slack WebClient.
`max_file_size`	`int`	`1073741824`	Maximum file size in bytes for uploads and downloads (default 1 GB).
`thread_message_limit`	`int`	`20`	Maximum number of messages to fetch in `get_thread`.

Toolkit Functions

Function	Description
`send_message(channel, text)`	Send a message to a Slack channel.
`send_message_thread(channel, text, thread_ts)`	Reply to a message thread in a channel.
`list_channels()`	List all channels in the workspace.
`get_channel_history(channel, limit=100)`	Get message history from a channel.
`upload_file(channel, content, filename, title?, initial_comment?, thread_ts?)`	Upload a file to a channel with optional caption.
`download_file(file_id, dest_path?)`	Download a file by file ID. Returns path or base64 content.
`search_messages(query, limit=20)`	Search messages across the workspace. Requires a user token (bot tokens return `not_allowed_token_type`).
`search_workspace(query, content_types?, channel_types?, limit=10, include_context_messages=True)`	Search messages, files, channels, and users across the workspace using Slack's Real-Time Search API. Only works through the Slack interface.
`get_thread(channel, thread_ts, limit=20)`	Get all messages in a thread by parent timestamp. Capped by `thread_message_limit`.
`list_users(limit=100)`	List all users in the workspace.
`get_user_info(user_id)`	Get detailed info about a user by user ID.
`get_channel_info(channel)`	Get channel metadata: name, topic, purpose, member count, and visibility.

Tip

search_messages supports Slack search modifiers: from:@user, in:#channel, has:link, before:2024-01-01, after:2024-01-01. Combine them to narrow results.

Developer Resources

book

Slack Interface

Streaming, sessions, file handling, and behavior details.

github

Source Code

View the SlackTools implementation on GitHub.