Slack Skill

Comprehensive Slack workspace integration with 30+ tools for messaging, channel management, user operations, reactions, pins, and more. Built with the Skill Engine SDK showcasing OAuth2 token-based authentication and the Slack Web API.

Overview

This skill provides full access to Slack's Web API, enabling automation of workspace communication and management tasks. It demonstrates type-safe parameter validation, structured error handling, and production-ready API integration patterns.

When to Use This Skill

Use this skill when you need to:

•Send messages to channels or direct messages to users
•Create, manage, and archive channels
•List and search workspace users and channels
•Add reactions and pin important messages
•Schedule messages for later delivery
•Manage threads and conversations
•Upload files and snippets
•Set user status and presence
•Search message history
•Automate Slack workflows

Prerequisites

•Slack Workspace: Admin or appropriate permissions
•Slack App: Create an app at api.slack.com/apps
•Bot Token: OAuth token with required scopes

Setting Up Your Slack App

•Go to https://api.slack.com/apps
•Click "Create New App" → "From scratch"
•Name your app (e.g., "Skill Engine Bot") and select your workspace
•Navigate to "OAuth & Permissions"

•Add Bot Token Scopes:

code

Required Scopes:
- chat:write           (Send messages)
- channels:read        (List public channels)
- users:read           (List users)
- reactions:write      (Add/remove reactions)
- pins:write           (Pin messages)
- channels:manage      (Create/archive channels)
- groups:write         (Manage private channels)
- im:write             (Send DMs)
- mpim:write           (Manage group DMs)
- search:read          (Search messages - optional)
- users:write          (Set status - optional)
- files:write          (Upload files - optional)

•Click "Install to Workspace" and authorize
•Copy the "Bot User OAuth Token" (starts with xoxb-)

Configuration

Set the Slack token as an environment variable:

bash

export SKILL_SLACK_TOKEN=xoxb-your-token-here

Or add to .skill-engine.toml:

toml

[skills.slack-skill.instances.default]
config.slack_token = "${SLACK_TOKEN}"

Tools

Messaging Tools (4 tools)

send-message

Send a message to a Slack channel.

Parameter	Type	Required	Description
channel	string	Yes	Channel name (without #) or channel ID
text	string	Yes	Message text (supports Slack markdown)
thread_ts	string	No	Thread timestamp to reply in thread

Examples:

bash

# Send to channel
skill run slack-skill send-message channel=general text="Hello team!"

# Send with markdown
skill run slack-skill send-message channel=dev text="*Important:* New release deployed :rocket:"

# Reply in thread
skill run slack-skill send-message channel=general text="Follow-up message" thread_ts=1234567890.123456

send-dm

Send a direct message to a user.

Parameter	Type	Required	Description
user	string	Yes	User ID (U12345) or @username
text	string	Yes	Message text

Examples:

bash

# Send DM by username
skill run slack-skill send-dm user=@john text="Hey, can you review PR #42?"

# Send DM by user ID
skill run slack-skill send-dm user=U12345ABC text="Meeting in 10 minutes"

update-message

Update an existing message.

Parameter	Type	Required	Description
channel	string	Yes	Channel ID
ts	string	Yes	Message timestamp
text	string	Yes	New message text

Example:

bash

skill run slack-skill update-message channel=C123ABC ts=1234567890.123456 text="Updated: Meeting at 3pm"

delete-message

Delete a message.

Parameter	Type	Required	Description
channel	string	Yes	Channel ID
ts	string	Yes	Message timestamp

Example:

bash

skill run slack-skill delete-message channel=C123ABC ts=1234567890.123456

schedule-message

Schedule a message for later delivery.

Parameter	Type	Required	Description
channel	string	Yes	Channel ID or name
text	string	Yes	Message text
post_at	number	Yes	Unix timestamp for when to post

Example:

bash

# Schedule message for tomorrow at 9am (Unix timestamp)
skill run slack-skill schedule-message channel=general text="Daily standup reminder" post_at=1704283200

get-thread-replies

Get all replies in a thread.

Parameter	Type	Required	Default	Description
channel	string	Yes	-	Channel ID
ts	string	Yes	-	Thread parent message timestamp
limit	number	No	50	Maximum replies to return

Example:

bash

skill run slack-skill get-thread-replies channel=C123ABC ts=1234567890.123456 limit=100

Channel Tools (6 tools)

list-channels

List channels in the workspace.

Parameter	Type	Required	Default	Description
type	string	No	public	Filter: public, private, all
limit	number	No	50	Maximum channels to return (1-200)

Examples:

bash

# List public channels
skill run slack-skill list-channels

# List all channels (public + private)
skill run slack-skill list-channels type=all limit=100

# List only private channels
skill run slack-skill list-channels type=private

get-channel-info

Get detailed information about a channel.

Parameter	Type	Required	Description
channel	string	Yes	Channel name or ID

Example:

bash

skill run slack-skill get-channel-info channel=general
skill run slack-skill get-channel-info channel=C123ABC

create-channel

Create a new channel.

Parameter	Type	Required	Default	Description
name	string	Yes	-	Channel name (lowercase, no spaces)
is_private	boolean	No	false	Create as private channel

Examples:

bash

# Create public channel
skill run slack-skill create-channel name=project-alpha

# Create private channel
skill run slack-skill create-channel name=leadership is_private=true

archive-channel

Archive a channel (make it read-only).

Parameter	Type	Required	Description
channel	string	Yes	Channel ID

Example:

bash

skill run slack-skill archive-channel channel=C123ABC

invite-to-channel

Invite users to a channel.

Parameter	Type	Required	Description
channel	string	Yes	Channel ID
users	string	Yes	Comma-separated user IDs

Example:

bash

skill run slack-skill invite-to-channel channel=C123ABC users=U111,U222,U333

kick-from-channel

Remove a user from a channel.

Parameter	Type	Required	Description
channel	string	Yes	Channel ID
user	string	Yes	User ID to remove

Example:

bash

skill run slack-skill kick-from-channel channel=C123ABC user=U12345

set-topic

Set the topic for a channel.

Parameter	Type	Required	Description
channel	string	Yes	Channel ID
topic	string	Yes	New topic text

Example:

bash

skill run slack-skill set-topic channel=C123ABC topic="Q1 2024 Planning"

set-purpose

Set the purpose/description for a channel.

Parameter	Type	Required	Description
channel	string	Yes	Channel ID
purpose	string	Yes	New purpose text

Example:

bash

skill run slack-skill set-purpose channel=C123ABC purpose="Discuss project alpha milestones"

User Tools (4 tools)

list-users

List users in the workspace.

Parameter	Type	Required	Default	Description
include_bots	boolean	No	false	Include bot users
limit	number	No	50	Maximum users to return (1-200)

Examples:

bash

# List human users
skill run slack-skill list-users

# Include bots
skill run slack-skill list-users include_bots=true limit=100

get-user-info

Get information about a specific user.

Parameter	Type	Required	Description
user	string	Yes	User ID or @username

Examples:

bash

skill run slack-skill get-user-info user=@john
skill run slack-skill get-user-info user=U12345ABC

get-presence

Get a user's presence status (active/away).

Parameter	Type	Required	Description
user	string	Yes	User ID

Example:

bash

skill run slack-skill get-presence user=U12345ABC

set-status

Set your own status (emoji and text).

Parameter	Type	Required	Description
status_text	string	Yes	Status text
status_emoji	string	No	Status emoji (e.g., :coffee:)
expiration	number	No	Unix timestamp when status expires

Examples:

bash

# Simple status
skill run slack-skill set-status status_text="In a meeting"

# Status with emoji
skill run slack-skill set-status status_text="On vacation" status_emoji=":palm_tree:"

# Status that expires in 1 hour
skill run slack-skill set-status status_text="Do not disturb" status_emoji=":no_entry_sign:" expiration=1704290400

Reaction Tools (2 tools)

react

Add a reaction emoji to a message.

Parameter	Type	Required	Description
channel	string	Yes	Channel ID
ts	string	Yes	Message timestamp
emoji	string	Yes	Emoji name (without colons)

Examples:

bash

skill run slack-skill react channel=C123ABC ts=1234567890.123456 emoji=thumbsup
skill run slack-skill react channel=C123ABC ts=1234567890.123456 emoji=rocket
skill run slack-skill react channel=C123ABC ts=1234567890.123456 emoji=heart

unreact

Remove a reaction from a message.

Parameter	Type	Required	Description
channel	string	Yes	Channel ID
ts	string	Yes	Message timestamp
emoji	string	Yes	Emoji name (without colons)

Example:

bash

skill run slack-skill unreact channel=C123ABC ts=1234567890.123456 emoji=thumbsup

Pin Tools (2 tools)

pin-message

Pin a message to a channel.

Parameter	Type	Required	Description
channel	string	Yes	Channel ID
ts	string	Yes	Message timestamp

Example:

bash

skill run slack-skill pin-message channel=C123ABC ts=1234567890.123456

unpin-message

Unpin a message from a channel.

Parameter	Type	Required	Description
channel	string	Yes	Channel ID
ts	string	Yes	Message timestamp

Example:

bash

skill run slack-skill unpin-message channel=C123ABC ts=1234567890.123456

Search & Files (2 tools)

search-messages

Search for messages across the workspace (requires search:read scope).

Parameter	Type	Required	Default	Description
query	string	Yes	-	Search query
count	number	No	20	Number of results
sort	string	No	score	Sort by: score or timestamp

Examples:

bash

# Search for messages
skill run slack-skill search-messages query="deployment failed"

# Search with more results
skill run slack-skill search-messages query="bug" count=50 sort=timestamp

upload-file

Upload content as a file (text snippets, code).

Parameter	Type	Required	Description
channels	string	Yes	Comma-separated channel IDs
content	string	Yes	File content
filename	string	Yes	Filename
filetype	string	No	File type (text, javascript, python, etc.)
title	string	No	File title
initial_comment	string	No	Comment to add with file

Examples:

bash

# Upload code snippet
skill run slack-skill upload-file \
  channels=C123ABC \
  content="console.log('Hello');" \
  filename=test.js \
  filetype=javascript \
  title="Test Script"

# Upload with comment
skill run slack-skill upload-file \
  channels=C123ABC,C456DEF \
  content="API logs from server..." \
  filename=logs.txt \
  filetype=text \
  initial_comment="Here are today's logs"

Utility Tools (1 tool)

test-connection

Test the Slack API connection and verify token.

Parameters: None

Example:

bash

skill run slack-skill test-connection
# Output: Connected to Slack!
#         Team: My Workspace
#         Bot User: skill-engine-bot

Workflows

Daily Standup Automation

bash

# Send standup reminder
skill run slack-skill send-message \
  channel=engineering \
  text=":wave: Good morning! Time for standup. Please share:\n1. What you did yesterday\n2. What you'll do today\n3. Any blockers?"

# React to responses
skill run slack-skill react channel=C123ABC ts=1234567890.123456 emoji=white_check_mark

Channel Management Workflow

bash

# Create project channel
skill run slack-skill create-channel name=project-phoenix

# Set topic and purpose
skill run slack-skill set-topic channel=C123ABC topic="Project Phoenix - Q1 2024"
skill run slack-skill set-purpose channel=C123ABC purpose="Coordinate Project Phoenix development"

# Invite team members
skill run slack-skill invite-to-channel channel=C123ABC users=U111,U222,U333

# Send welcome message
skill run slack-skill send-message channel=project-phoenix text="Welcome to Project Phoenix! :rocket:"

Notification & Alert Workflow

bash

# Send alert to channel
skill run slack-skill send-message \
  channel=alerts \
  text=":rotating_light: *ALERT:* Database CPU usage >90%\nServer: prod-db-01\nTime: $(date)"

# Send DM to on-call engineer
skill run slack-skill send-dm \
  user=@oncall \
  text="FYI: Alert triggered for database. Check #alerts channel."

# Pin critical message
skill run slack-skill pin-message channel=C123ABC ts=1234567890.123456

Status Update Workflow

bash

# Set away status
skill run slack-skill set-status \
  status_text="Lunch break" \
  status_emoji=":fork_and_knife:" \
  expiration=$(date -d '+1 hour' +%s)

# Update channel topic with current sprint
skill run slack-skill set-topic \
  channel=C123ABC \
  topic="Sprint 42 (Jan 2-15) | Goal: Launch beta | Daily standup @9am"

Error Handling

The skill provides clear error messages for common issues:

Error	Cause	Solution
401 Authentication failed	Invalid or missing token	Check `SKILL_SLACK_TOKEN` is set correctly
429 Rate limit exceeded	Too many requests	Wait and retry (headers show reset time)
channel_not_found	Channel doesn't exist	Verify channel name/ID
not_in_channel	Bot not in channel	Invite bot to channel first
invalid_auth	Token revoked or expired	Generate new token from Slack app settings
missing_scope	Token lacks required permission	Add scope in Slack app OAuth settings and reinstall

Rate Limits

Slack API has tiered rate limits:

•Tier 1 (most endpoints): 1 request per second
•Tier 2 (chat.postMessage): 1 request per second per channel
•Tier 3 (search, files): Lower limits
•Tier 4 (special methods): Higher limits

The skill handles rate limit errors and includes retry information.

Security Notes

•Token Security: Store tokens in environment variables, never in code
•Scope Minimization: Only request scopes your bot needs
•Channel Access: Bot can only access public channels and private channels it's invited to
•User Privacy: Cannot read DMs between users (only bot's own DMs)
•Audit Logs: Slack maintains audit logs of all bot actions

Best Practices

•Use Channel Names When Possible: More readable than IDs in scripts
•Check Responses: Slack returns ok: false for API errors even with 200 status
•Thread Conversations: Use thread_ts to keep related messages together
•Format Messages: Use Slack's markdown for better readability
•Test in Private Channels: Test bots in private channels before public use
•Monitor Rate Limits: Check X-Rate-Limit-* headers in responses
•Handle Errors Gracefully: Retry on rate limits, fail clearly on auth errors

Slack Markdown Reference

code

*bold text*
_italic text_
~strikethrough~
`code`
```code block```
> quote
• bulleted list
1. numbered list
<URL|link text>
<@U12345> (mention user)
<#C12345> (link to channel)
:emoji: (emoji by name)

Troubleshooting

Bot Not Receiving Permissions

bash

# Verify scopes in Slack app settings
# Reinstall app to workspace
# Test connection
skill run slack-skill test-connection

Cannot Find Channel

bash

# List all channels bot can see
skill run slack-skill list-channels type=all

# Check if bot is invited to private channel
# Invite bot via Slack UI: /invite @your-bot-name

Messages Not Sending

bash

# Verify token is set
echo $SKILL_SLACK_TOKEN

# Test connection
skill run slack-skill test-connection

# Check channel name (without #)
skill run slack-skill send-message channel=general text="Test"  # Correct
skill run slack-skill send-message channel=#general text="Test" # May fail

SDK Features Demonstrated

This skill showcases advanced SDK patterns:

1. Authenticated HTTP Client

typescript

const client = createAuthenticatedClient({
  baseUrl: 'https://slack.com/api',
  authType: 'bearer',
  tokenKey: 'SLACK_TOKEN',
});

2. Error Handling with Context

typescript

if (response.status === 429) {
  return err('Rate limit exceeded', errors.rateLimit());
}

3. Parameter Validation

typescript

{
  name: 'channel',
  paramType: 'string',
  validation: {
    minLength: 1,
    maxLength: 80,
  },
}

4. Enum Validation

typescript

{
  name: 'type',
  paramType: 'string',
  validation: {
    enum: ['public', 'private', 'all'],
  },
}

Resources

Contributing

Contributions welcome! Possible enhancements:

•Slash command support
•Interactive message components
•Event subscriptions
•File download support
•Workflow builder integration
•Enterprise Grid features