Slack Tools

Category: network · 6 tools

Slack Web API tools — post messages, reply in threads, react to messages, read channel history, read thread replies, and verify bot identity.

Setup

Environment Variable

Set your Slack bot token before using these tools:

export TOOLPACK_SLACK_BOT_TOKEN=xoxb-your-bot-token

All tools read TOOLPACK_SLACK_BOT_TOKEN by default. You can also pass a token parameter directly to any tool call to override the environment variable.

Import

import { slackToolsProject } from 'toolpack-sdk';

Wire up with Toolpack

import Toolpack from 'toolpack-sdk';
import { slackToolsProject } from 'toolpack-sdk';

const toolpack = await Toolpack.init({
    provider: 'openai',
    tools: true,
    toolProjects: [slackToolsProject],
});

Tools

Tool	Required Parameters	Optional Parameters	Description
slack.chat.postMessage	channel, text	thread_ts, blocks, token	Post a message to a channel or thread
slack.chat.postEphemeral	channel, user, text	thread_ts, token	Post a temporary message visible only to a specific user
slack.reactions.add	channel, timestamp, name	token	Add an emoji reaction to a message
slack.conversations.history	channel	limit, oldest, latest, token	Fetch recent messages from a channel
slack.conversations.replies	channel, ts	limit, oldest, latest, token	Fetch all replies in a thread
slack.auth.test	—	token	Verify the bot token and retrieve bot identity

Tool Reference

slack.chat.postMessage

Post a message to a Slack channel or thread. Supports plain mrkdwn text and optional Block Kit blocks for rich formatting. Use thread_ts to reply inside an existing thread.

Parameter	Type	Required	Description
channel	string	Yes	Channel ID or channel name (e.g. #general)
text	string	Yes	Message text in Slack mrkdwn format. Always required — used as fallback when blocks are provided
thread_ts	string	No	Timestamp of the parent message to reply in a thread. Omit to post at top level
blocks	string	No	Optional Block Kit layout as a JSON string. When provided, text is used only as the notification fallback
token	string	No	Slack bot token. Defaults to TOOLPACK_SLACK_BOT_TOKEN env var

slack.chat.postEphemeral

Post a temporary message visible only to a specific user in a Slack channel. Useful for private confirmations, status updates, or error messages that should not be seen by others.

Parameter	Type	Required	Description
channel	string	Yes	Channel ID where the ephemeral message will appear
user	string	Yes	Slack user ID of the person who will see the message
text	string	Yes	Message text in Slack mrkdwn format
thread_ts	string	No	Timestamp of the parent message to show the ephemeral reply inside a thread
token	string	No	Slack bot token. Defaults to TOOLPACK_SLACK_BOT_TOKEN env var

slack.reactions.add

Add an emoji reaction to a Slack message. Useful for acknowledging receipt, signalling completion, or flagging issues. Requires the reactions:write OAuth scope on the Slack app.

Parameter	Type	Required	Description
channel	string	Yes	Channel ID containing the message to react to
timestamp	string	Yes	Timestamp of the message to react to
name	string	Yes	Emoji name without colons (e.g. "eyes", "white_check_mark", "warning", "x")
token	string	No	Slack bot token. Defaults to TOOLPACK_SLACK_BOT_TOKEN env var

slack.conversations.history

Fetch recent messages from a Slack channel. Useful for reading conversation context, checking what was discussed, or finding a specific message timestamp to react to or thread-reply into.

Parameter	Type	Required	Description
channel	string	Yes	Channel ID to fetch history from
limit	integer	No	Maximum number of messages to return. Defaults to 10, max 100
oldest	string	No	Only return messages after this Unix timestamp (inclusive)
latest	string	No	Only return messages before this Unix timestamp (exclusive)
token	string	No	Slack bot token. Defaults to TOOLPACK_SLACK_BOT_TOKEN env var

slack.conversations.replies

Fetch all replies in a Slack thread. Use this to read the full conversation history of a thread, including who replied and when. Requires the channel ID and the timestamp (ts) of the parent message that started the thread.

Parameter	Type	Required	Description
channel	string	Yes	Channel ID that contains the thread
ts	string	Yes	Timestamp of the parent message that started the thread
limit	integer	No	Maximum number of replies to return. Defaults to 20, max 100
oldest	string	No	Only return replies after this Unix timestamp (inclusive)
latest	string	No	Only return replies before this Unix timestamp (exclusive)
token	string	No	Slack bot token. Defaults to TOOLPACK_SLACK_BOT_TOKEN env var

slack.auth.test

Verify the bot token and retrieve the identity of the calling app. Returns the bot_id, user_id, team, and workspace URL. Use this when the bot_id is not configured and is needed for self-suppression or other identity checks.

Parameter	Type	Required	Description
token	string	No	Slack bot token. Defaults to TOOLPACK_SLACK_BOT_TOKEN env var

Examples

Posting a Message

const stream = toolpack.stream({
    messages: [{ role: 'user', content: 'Post "Deploy complete" to the #deployments channel' }],
    model: 'gpt-4o',
});
// AI uses slack.chat.postMessage

Reading Channel History

const stream = toolpack.stream({
    messages: [{ role: 'user', content: 'What were the last 5 messages in #general?' }],
    model: 'gpt-4o',
});
// AI uses slack.conversations.history

Replying in a Thread

const stream = toolpack.stream({
    messages: [{ role: 'user', content: 'Reply to the thread at ts 1234567890.123456 in #alerts' }],
    model: 'gpt-4o',
});
// AI uses slack.conversations.replies then slack.chat.postMessage with thread_ts

Adding a Reaction

const stream = toolpack.stream({
    messages: [{ role: 'user', content: 'Add a white_check_mark reaction to the latest message in #deployments' }],
    model: 'gpt-4o',
});
// AI uses slack.conversations.history then slack.reactions.add