Mode: Cognitive/Prompt-Driven — No standalone utility script; use via agent context.

Slack Notifications Skill

Overview

This skill provides Slack API operations with progressive disclosure for optimal context usage.

Context Savings: ~90% reduction

MCP Mode: ~15,000 tokens always loaded (30+ tools)
Skill Mode: ~500 tokens metadata + on-demand loading

Requirements

SLACK_BOT_TOKEN environment variable (required)
SLACK_SIGNING_SECRET environment variable (optional, for event verification)
SLACK_APP_TOKEN environment variable (optional, for Socket Mode)

Setting up Slack Bot Token

Create a Slack App at https://api.slack.com/apps
Navigate to "OAuth & Permissions"
Add required bot token scopes:
- chat:write - Send messages
- channels:read - List channels
- channels:history - Read channel history
- users:read - List users
- files:write - Upload files
- reactions:write - Add reactions
Install app to workspace
Copy "Bot User OAuth Token" to SLACK_BOT_TOKEN environment variable

Tools

The skill provides 14 tools across 5 categories:

Category	Tools	Confirmation Required
Messaging	post-message, post-thread, update-message, delete-message	Yes (all)
Channels	list-channels, get-channel, channel-history	No
Users	list-users, get-user, user-presence	No
Files	upload-file, list-files	Yes (upload only)
Reactions	add-reaction, get-reactions	No

Quick Reference

# Post message to channel
curl -X POST https://slack.com/api/chat.postMessage \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"channel": "C1234567890", "text": "Hello from Claude!"}'

# List channels
curl -X GET "https://slack.com/api/conversations.list" \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN"

# Upload file
curl -X POST https://slack.com/api/files.upload \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN" \
  -F "channels=C1234567890" \
  -F "file=@report.pdf" \
  -F "title=Weekly Report"

Tool Details

Messaging Tools (Confirmation Required)

post-message

Send a message to a Slack channel.

Parameters:

channel (required): Channel ID or name (e.g., "C1234567890" or "#general")
text (required): Message text (supports Slack markdown)
thread_ts (optional): Parent message timestamp for threading
blocks (optional): Rich message blocks (JSON array)

Example:

curl -X POST https://slack.com/api/chat.postMessage \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "channel": "C1234567890",
    "text": "Deployment successful!",
    "blocks": [
      {
        "type": "section",
        "text": {
          "type": "mrkdwn",
          "text": "*Deployment Status*\n:white_check_mark: Production deployed successfully"
        }
      }
    ]
  }'

post-thread

Reply to a message in a thread.

Parameters:

channel (required): Channel ID
thread_ts (required): Parent message timestamp
text (required): Reply text

Example:

curl -X POST https://slack.com/api/chat.postMessage \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "channel": "C1234567890",
    "thread_ts": "1234567890.123456",
    "text": "Thread reply here"
  }'

update-message

Update an existing message.

Parameters:

channel (required): Channel ID
ts (required): Message timestamp
text (required): New message text

Example:

curl -X POST https://slack.com/api/chat.update \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "channel": "C1234567890",
    "ts": "1234567890.123456",
    "text": "Updated message"
  }'

delete-message

Delete a message.

Parameters:

channel (required): Channel ID
ts (required): Message timestamp

Example:

curl -X POST https://slack.com/api/chat.delete \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "channel": "C1234567890",
    "ts": "1234567890.123456"
  }'

Channel Tools

list-channels

List all channels in workspace.

Parameters:

types (optional): Comma-separated channel types (default: "public_channel")
- Options: "public_channel", "private_channel", "mpim", "im"
limit (optional): Max channels to return (default: 100)

Example:

curl -X GET "https://slack.com/api/conversations.list?types=public_channel,private_channel" \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN"

get-channel

Get channel information.

Parameters:

channel (required): Channel ID

Example:

curl -X GET "https://slack.com/api/conversations.info?channel=C1234567890" \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN"

channel-history

Get channel message history.

Parameters:

channel (required): Channel ID
limit (optional): Max messages to return (default: 100)
oldest (optional): Start of time range (Unix timestamp)
latest (optional): End of time range (Unix timestamp)

Example:

curl -X GET "https://slack.com/api/conversations.history?channel=C1234567890&limit=50" \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN"

Security Note: Channel history may contain sensitive information. Use with caution.

File Tools

upload-file (Confirmation Required)

Upload a file to Slack channel.

Parameters:

channels (required): Comma-separated channel IDs
file (required): File path to upload
title (optional): File title
initial_comment (optional): Message text

Example:

curl -X POST https://slack.com/api/files.upload \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN" \
  -F "channels=C1234567890" \
  -F "file=@C:\reports\weekly.pdf" \
  -F "title=Weekly Report" \
  -F "initial_comment=Here is this week's report"

list-files

List files in channel.

Parameters:

channel (optional): Channel ID to filter by
user (optional): User ID to filter by
count (optional): Max files to return (default: 100)

Example:

curl -X GET "https://slack.com/api/files.list?channel=C1234567890" \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN"

Reaction Tools

add-reaction

Add emoji reaction to a message.

Parameters:

channel (required): Channel ID
timestamp (required): Message timestamp
name (required): Emoji name (without colons, e.g., "thumbsup")

Example:

curl -X POST https://slack.com/api/reactions.add \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "channel": "C1234567890",
    "timestamp": "1234567890.123456",
    "name": "thumbsup"
  }'

get-reactions

Get reactions on a message.

Parameters:

channel (required): Channel ID
timestamp (required): Message timestamp

Example:

curl -X GET "https://slack.com/api/reactions.get?channel=C1234567890&timestamp=1234567890.123456" \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN"

Agent Integration

Primary Agents

devops: Infrastructure alerts, deployment notifications, monitoring
incident-responder: Incident alerts, status updates, escalations

Secondary Agents

pm: Sprint notifications, milestone updates, team announcements
developer: Build notifications, PR alerts, test results
qa: Test failure alerts, quality reports
security-architect: Security alerts, vulnerability notifications

Common Use Cases

Deployment Notifications

# Notify channel of successful deployment
curl -X POST https://slack.com/api/chat.postMessage \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "channel": "#deployments",
    "text": ":rocket: Production deployment completed",
    "blocks": [
      {
        "type": "section",
        "text": {
          "type": "mrkdwn",
          "text": "*Production Deployment*\n:white_check_mark: v1.2.3 deployed successfully\n*Duration:* 5m 23s"
        }
      }
    ]
  }'

Incident Alerts

# Alert on-call team of incident
curl -X POST https://slack.com/api/chat.postMessage \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "channel": "#incidents",
    "text": "<!channel> :rotating_light: High severity incident detected",
    "blocks": [
      {
        "type": "section",
        "text": {
          "type": "mrkdwn",
          "text": "*Incident INC-1234*\n:rotating_light: *Severity:* P1\n*Service:* API Gateway\n*Status:* 503 errors increasing"
        }
      }
    ]
  }'

Test Results

# Post test results
curl -X POST https://slack.com/api/chat.postMessage \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "channel": "#qa",
    "text": "Test suite completed",
    "blocks": [
      {
        "type": "section",
        "text": {
          "type": "mrkdwn",
          "text": "*Test Results*\n:white_check_mark: 245 passed\n:x: 3 failed\n:warning: 2 skipped"
        }
      }
    ]
  }'

Security Considerations

Token Security

NEVER expose bot token in logs or error messages
Store token in environment variable, not in code
Use least-privilege scopes for bot token
Rotate tokens periodically

Message Security

All message operations require confirmation
Channel history may contain sensitive information (PII, credentials, etc.)
Validate channel permissions before posting
Use private channels for sensitive communications

Data Privacy

Comply with workspace data retention policies
Avoid posting PII or credentials in messages
Use Slack's data export features for compliance
Respect user privacy and online status

Error Handling

Common Errors

Error	Cause	Solution
`not_authed`	Missing or invalid token	Check `SLACK_BOT_TOKEN` is set correctly
`channel_not_found`	Invalid channel ID	Verify channel ID with `list-channels`
`missing_scope`	Bot lacks required permission	Add scope in Slack App settings
`rate_limited`	Too many requests	Implement exponential backoff
`message_not_found`	Invalid timestamp	Check message timestamp is correct

Retry Strategy

For rate limiting errors, implement exponential backoff:

Wait 1 second, retry
Wait 2 seconds, retry
Wait 4 seconds, retry
Wait 8 seconds, retry
Give up after 5 attempts

Rate Limits

Slack API rate limits:

Tier 1: 1 request per second
Tier 2: 20 requests per minute
Tier 3: 50 requests per minute
Tier 4: 100 requests per minute

Methods by tier:

chat.postMessage: Tier 3 (50/min)
conversations.list: Tier 2 (20/min)
users.list: Tier 2 (20/min)
files.upload: Tier 4 (100/min)

Slack API Documentation: https://api.slack.com/docs
Block Kit Builder: https://app.slack.com/block-kit-builder
Slack App Management: https://api.slack.com/apps

Memory Protocol (MANDATORY)

Before starting: Read .claude/context/memory/learnings.md

After completing:

New pattern -> .claude/context/memory/learnings.md
Issue found -> .claude/context/memory/issues.md
Decision made -> .claude/context/memory/decisions.md

ASSUME INTERRUPTION: If it's not in memory, it didn't happen.

slack-notifications

Slack Notifications Skill

Overview

Requirements

Setting up Slack Bot Token

Tools

Quick Reference

Tool Details

Messaging Tools (Confirmation Required)

post-message

post-thread

update-message

delete-message

Channel Tools

list-channels

get-channel

channel-history

User Tools

list-users

get-user

user-presence

File Tools

upload-file (Confirmation Required)

list-files

Reaction Tools

add-reaction

get-reactions

Agent Integration

Primary Agents

Secondary Agents

Common Use Cases

Deployment Notifications

Incident Alerts

Test Results

Security Considerations

Token Security

Message Security

Data Privacy

Error Handling

Common Errors

Retry Strategy

Rate Limits

Related

Memory Protocol (MANDATORY)