Module 3: Slack Notification - Starter

This starter code extends Modules 1 and 2 with Slack integration, demonstrating how to combine MCP Tools and Prompts for complete team communication workflows.

What You'll Implement

In this module, you'll complete:

1. send_slack_notification tool - Send messages to Slack via webhook
2. format_ci_failure_alert prompt - Format CI failures for Slack
3. format_ci_success_summary prompt - Format successful deployments for Slack

Prerequisites

• Completed Modules 1 and 2
• A Slack workspace with webhook permissions
• Environment variable: SLACK_WEBHOOK_URL

Setup

1. Install dependencies:

   uv sync

2. Set up Slack webhook:

   • Create Slack app at https://api.slack.com/apps
   • App name: "MCP Course Notifications"
   • Enable incoming webhooks
   • Add webhook to workspace
   • Export URL: export SLACK_WEBHOOK_URL="https://hooks.slack.com/services/..."

3. Test webhook:

   curl -X POST -H 'Content-type: application/json' \
     --data '{"text":"Hello from MCP Course!"}' \
     $SLACK_WEBHOOK_URL

Implementation Tasks

1. Complete send_slack_notification Tool

In server.py, implement the TODO sections:

@mcp.tool()
async def send_slack_notification(message: str) -> str:
    # TODO: Import requests library at top of file
    # TODO: Send POST request to webhook_url
    # TODO: Include message in JSON payload: {"text": message}
    # TODO: Handle response and return status

2. Test the Prompts

The formatting prompts are complete - test them with Claude Code:

• Use format_ci_failure_alert to create failure messages
• Use format_ci_success_summary to create success messages
• Send formatted messages using your send_slack_notification tool

3. End-to-End Workflow

Test the complete integration:

1. Start webhook server: python webhook_server.py
2. Start MCP server: uv run server.py
3. Start Cloudflare tunnel: cloudflared tunnel --url http://localhost:8080
4. Trigger GitHub Actions
5. Use prompts to format messages
6. Send to Slack and verify formatting

Expected Slack Output

Failure Alert:

❌ *CI Failed* - mcp-course

> Tests failed in Module 3 implementation

*Details:*
• Workflow: `CI`
• Branch: `feature/slack-integration`
• Commit: `abc123f`

*Next Steps:*
• <https://github.com/user/mcp-course/pull/42|View Pull Request>
• <https://github.com/user/mcp-course/actions/runs/123|Check Action Logs>

Security Note

⚠️ Important: The SLACK_WEBHOOK_URL is a sensitive secret that grants permission to post messages to your Slack channel. Always:

• Store it as an environment variable, never in code
• Never commit webhook URLs to version control
• Treat it like a password

Available Tools & Prompts

This module includes all tools and prompts from Modules 1 & 2, plus:

New Tools:

• send_slack_notification - Send messages to Slack

New Prompts:

• format_ci_failure_alert - Create failure alerts
• format_ci_success_summary - Create success summaries

From Previous Modules:

• All file analysis tools (Module 1)
• All GitHub Actions tools (Module 2)
• All CI/CD analysis prompts (Module 2)

Testing Your Implementation

1. Tool Test: Call send_slack_notification directly with a test message
2. Prompt Test: Use formatting prompts to generate messages, then send them
3. Integration Test: Full workflow from GitHub webhook to Slack notification
4. Format Test: Verify Slack markdown renders correctly in your channel

Next Steps

Once complete, you'll have built a production-ready MCP server that demonstrates all core MCP primitives working together for real-world team automation!