Slack Integration: Build a Team Notification Skill

Development doesn't happen in isolation. Teams need to know when deployments finish, when builds break, when PRs need review. But constant context switching between code and Slack destroys productivity.

What if Claude Code could handle team communication for you? Post deployment notifications, request reviews, share updates—all without leaving your terminal.

This tutorial shows you how to build a Slack integration skill that keeps your team informed without interrupting your flow.

Prerequisites

Slack Setup

You'll need:

1. A Slack workspace where you can add apps
2. Permission to create a Slack App or use an existing webhook

Two Integration Approaches

Webhooks (Simpler):

• One-way: Send messages only
• Easy setup: Just a URL
• Limited: Can't read messages or respond

Slack App (Full Featured):

• Two-way: Send and receive
• Rich features: Interactive buttons, threads
• More setup: OAuth, scopes, etc.

We'll cover both, starting with webhooks.

Webhook Integration

Setting Up a Webhook

1. Go to api.slack.com/apps
2. Create New App > From scratch
3. Choose your workspace
4. Go to "Incoming Webhooks" > Activate
5. Add New Webhook to Workspace
6. Choose a channel
7. Copy the webhook URL

Store the webhook URL securely:

# Add to .env (don't commit this!)
SLACK_WEBHOOK_URL=https://hooks.slack.com/services/T00000000/B00000000/XXXXXXXXXXXXXXXXXXXXXXXX

Basic Notification Skill

.claude/commands/notify.md:

---
description: Send a notification to Slack
arguments:
  - name: message
    description: Message to send
    required: true
  - name: channel
    description: Channel override (if multiple webhooks configured)
    required: false
---

# Slack Notification

Send a message to the team Slack channel.

## Send Message

Use curl to post to the webhook:

```bash
curl -X POST -H 'Content-type: application/json' \
  --data '{"text":"MESSAGE_HERE"}' \
  $SLACK_WEBHOOK_URL

Message Formatting

Slack supports mrkdwn format:

• bold → bold
• italic → italic
• code → code
• code block → code block
• <URL|text> → text
• :emoji: → emoji

Output

Confirm message was sent or report error.

### Rich Notification Skill

**.claude/commands/slack-notify.md:**

```markdown
---
description: Send rich Slack notifications
arguments:
  - name: type
    description: Notification type (deploy, build, pr, custom)
    required: true
  - name: status
    description: Status (success, failure, warning, info)
    required: false
    default: info
  - name: message
    description: Custom message
    required: false
---

# Rich Slack Notifications

Send formatted notifications with context.

## Message Templates

### Deploy Notification

```json
{
  "blocks": [
    {
      "type": "header",
      "text": {
        "type": "plain_text",
        "text": "🚀 Deployment Complete",
        "emoji": true
      }
    },
    {
      "type": "section",
      "fields": [
        {
          "type": "mrkdwn",
          "text": "*Environment:*\nProduction"
        },
        {
          "type": "mrkdwn",
          "text": "*Version:*\nv1.2.3"
        },
        {
          "type": "mrkdwn",
          "text": "*Deployed by:*\n@username"
        },
        {
          "type": "mrkdwn",
          "text": "*Time:*\n2 minutes"
        }
      ]
    },
    {
      "type": "section",
      "text": {
        "type": "mrkdwn",
        "text": "*Changes:*\n• Feature A\n• Bug fix B\n• Update C"
      }
    },
    {
      "type": "actions",
      "elements": [
        {
          "type": "button",
          "text": {
            "type": "plain_text",
            "text": "View Deployment"
          },
          "url": "https://app.example.com"
        }
      ]
    }
  ]
}

Build Notification

{
  "blocks": [
    {
      "type": "header",
      "text": {
        "type": "plain_text",
        "text": "✅ Build Passed",
        "emoji": true
      }
    },
    {
      "type": "section",
      "fields": [
        {
          "type": "mrkdwn",
          "text": "*Branch:*\nmain"
        },
        {
          "type": "mrkdwn",
          "text": "*Commit:*\n<commit_url|abc1234>"
        },
        {
          "type": "mrkdwn",
          "text": "*Duration:*\n4m 23s"
        },
        {
          "type": "mrkdwn",
          "text": "*Tests:*\n142 passed"
        }
      ]
    }
  ]
}

PR Notification

{
  "blocks": [
    {
      "type": "header",
      "text": {
        "type": "plain_text",
        "text": "📝 PR Ready for Review",
        "emoji": true
      }
    },
    {
      "type": "section",
      "text": {
        "type": "mrkdwn",
        "text": "*<pr_url|#42 Add user authentication>*\nby @author"
      }
    },
    {
      "type": "section",
      "text": {
        "type": "mrkdwn",
        "text": "This PR adds complete authentication with login, logout, and session management."
      }
    },
    {
      "type": "section",
      "fields": [
        {
          "type": "mrkdwn",
          "text": "*Files:*\n12 changed"
        },
        {
          "type": "mrkdwn",
          "text": "*Lines:*\n+450 / -23"
        }
      ]
    },
    {
      "type": "actions",
      "elements": [
        {
          "type": "button",
          "text": {
            "type": "plain_text",
            "text": "Review PR"
          },
          "url": "pr_url",
          "style": "primary"
        }
      ]
    }
  ]
}

Status Colors

Add color to indicate status:

{
  "attachments": [
    {
      "color": "#36a64f",  // green for success
      "blocks": [...]
    }
  ]
}

Colors:

• Success: #36a64f (green)
• Failure: #dc3545 (red)
• Warning: #ffc107 (yellow)
• Info: #17a2b8 (blue)

Send Notification

curl -X POST -H 'Content-type: application/json' \
  --data '[JSON_PAYLOAD]' \
  $SLACK_WEBHOOK_URL

## Full Slack App Integration

For two-way communication and advanced features, create a full Slack App.

### Setting Up the Slack App

1. Go to [api.slack.com/apps](https://api.slack.com/apps)
2. Create New App > From scratch
3. Add OAuth scopes:
   - `chat:write` - Send messages
   - `chat:write.public` - Post to any public channel
   - `channels:read` - List channels
   - `users:read` - Get user info
4. Install to workspace
5. Copy the Bot User OAuth Token

Store securely:

```bash
SLACK_BOT_TOKEN=xoxb-your-bot-token

MCP Server for Slack

Create an MCP server for Slack integration:

slack-mcp/src/index.ts:

import { Server } from "@modelcontextprotocol/sdk/server/index.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import {
  CallToolRequestSchema,
  ListToolsRequestSchema,
} from "@modelcontextprotocol/sdk/types.js";

const SLACK_BOT_TOKEN = process.env.SLACK_BOT_TOKEN;

async function slackAPI(endpoint: string, body: any) {
  const response = await fetch(`https://slack.com/api/${endpoint}`, {
    method: 'POST',
    headers: {
      'Authorization': `Bearer ${SLACK_BOT_TOKEN}`,
      'Content-Type': 'application/json',
    },
    body: JSON.stringify(body),
  });
  return response.json();
}

const server = new Server(
  { name: "slack-server", version: "1.0.0" },
  { capabilities: { tools: {} } }
);

server.setRequestHandler(ListToolsRequestSchema, async () => ({
  tools: [
    {
      name: "send_message",
      description: "Send a message to a Slack channel",
      inputSchema: {
        type: "object",
        properties: {
          channel: { type: "string", description: "Channel ID or name" },
          text: { type: "string", description: "Message text" },
          thread_ts: { type: "string", description: "Thread timestamp for replies" },
        },
        required: ["channel", "text"],
      },
    },
    {
      name: "list_channels",
      description: "List available Slack channels",
      inputSchema: { type: "object", properties: {} },
    },
    {
      name: "get_channel_history",
      description: "Get recent messages from a channel",
      inputSchema: {
        type: "object",
        properties: {
          channel: { type: "string" },
          limit: { type: "number", default: 10 },
        },
        required: ["channel"],
      },
    },
  ],
}));

server.setRequestHandler(CallToolRequestSchema, async (request) => {
  const { name, arguments: args } = request.params;

  switch (name) {
    case "send_message": {
      const result = await slackAPI("chat.postMessage", {
        channel: args.channel,
        text: args.text,
        thread_ts: args.thread_ts,
      });
      return {
        content: [{
          type: "text",
          text: result.ok
            ? `Message sent to ${args.channel}`
            : `Error: ${result.error}`,
        }],
      };
    }

    case "list_channels": {
      const result = await slackAPI("conversations.list", {
        types: "public_channel,private_channel",
      });
      const channels = result.channels?.map((c: any) =>
        `#${c.name} (${c.id})`
      ).join("\n");
      return {
        content: [{ type: "text", text: channels || "No channels found" }],
      };
    }

    case "get_channel_history": {
      const result = await slackAPI("conversations.history", {
        channel: args.channel,
        limit: args.limit || 10,
      });
      const messages = result.messages?.map((m: any) =>
        `${m.user}: ${m.text}`
      ).join("\n\n");
      return {
        content: [{ type: "text", text: messages || "No messages" }],
      };
    }

    default:
      throw new Error(`Unknown tool: ${name}`);
  }
});

async function main() {
  const transport = new StdioServerTransport();
  await server.connect(transport);
}

main().catch(console.error);

Configure MCP

.claude/mcp.json:

{
  "mcpServers": {
    "slack": {
      "command": "npx",
      "args": ["ts-node", "/path/to/slack-mcp/src/index.ts"],
      "env": {
        "SLACK_BOT_TOKEN": "${SLACK_BOT_TOKEN}"
      }
    }
  }
}

Automated Notification Workflows

Deploy Notification Agent

.claude/agents/deploy-notify.md:

---
description: Send deployment notifications to Slack
trigger:
  event: post-deploy
---

# Deployment Notification Agent

After deployments, notify the team on Slack.

## Gather Information

1. Get deployment details:
   - Version deployed
   - Environment
   - Who deployed
   - Duration

2. Get changes included:
   - Commits since last deploy
   - PRs merged
   - Issues resolved

## Compose Message

🚀 Deployment Complete

Environment: [env] Version: [version] Deployed by: @[user] Duration: [time]

Changes: • [Change 1] • [Change 2] • [Change 3]

Resolved Issues: • #42 - Login bug • #38 - Performance issue

<url|View Deployment>

## Send Notification

Use Slack MCP or webhook to post to #deployments channel.

## Handle Failures

If deployment failed:
- Use red color
- Include error summary
- Tag on-call person
- Include rollback instructions

PR Review Request Agent

.claude/agents/review-request.md:

---
description: Request PR reviews via Slack
trigger:
  event: pr-created
  condition: "not draft"
---

# PR Review Request Agent

When a PR is ready for review, notify potential reviewers.

## Determine Reviewers

Based on:
1. Code owners for changed files
2. Recent contributors to affected areas
3. Team rotation schedule (if configured)

## Check Availability

If integrated with calendar:
- Skip people in meetings
- Skip people on PTO
- Prefer people in similar timezone

## Send Request

📝 Review Requested

<pr_url|#42 Add user authentication> by @author

[Brief description of changes]

Files Changed:

• src/auth/login.ts
• src/auth/session.ts
• tests/auth.test.ts

@reviewer1 @reviewer2 - Please review when available

<pr_url|View PR>

## Follow Up

If no review after 24 hours:
- Send reminder
- Expand reviewer pool
- Escalate if critical

Build Failure Agent

.claude/agents/build-alert.md:

---
description: Alert on build failures
trigger:
  event: ci-failure
---

# Build Failure Alert Agent

When CI fails, notify the team and the commit author.

## Analyze Failure

1. Get failure details
2. Identify failing step
3. Extract error message
4. Find recent changes

## Notify

### To #builds channel:

❌ Build Failed

Branch: [branch] Commit: <commit_url|abc1234> by @author

Failed Step: [step name] Error:

[error message]

@author - Please check and fix

<run_url|View Build>

### DM to author (if enabled):

Hey! Your recent commit broke the build.

Error: [summary]

<run_url|View Details>

Need help? Ask in #dev-help

## Track

Log failure for metrics:
- Time to fix
- Failure frequency
- Common failure types

Team Coordination Skills

Standup Reminder

.claude/commands/standup.md:

---
description: Post standup reminder with context
---

# Standup Reminder

Post a standup reminder with relevant context for the team.

## Gather Context

1. Yesterday's activity:
   - PRs merged
   - Issues closed
   - Deployments

2. Today's priorities:
   - Open PRs needing review
   - Issues in progress
   - Upcoming deadlines

## Post Reminder

🌅 Good morning team!

Yesterday: • Merged 3 PRs • Closed 5 issues • Deployed v1.2.3 to production

Today's Focus: • 2 PRs awaiting review • Sprint ends Friday

Blockers? React with 🚧

Time for standup! Share your updates: • What did you do yesterday? • What are you doing today? • Any blockers?

Weekly Summary

.claude/commands/weekly-summary.md:

---
description: Post weekly development summary
---

# Weekly Summary

Generate and post a summary of the week's development activity.

## Gather Data

From GitHub:
- PRs merged
- Issues closed
- New issues created
- Releases published

From CI:
- Build success rate
- Deploy count
- Test coverage changes

## Generate Summary

📊 Weekly Development Summary Week of [date]

Highlights: • Released v1.3.0 with new dashboard • Reduced load time by 40% • Onboarded 2 new team members

Stats:

Contributors: 🏆 @developer1 - 5 PRs merged 🥈 @developer2 - 4 PRs merged 🥉 @developer3 - 3 PRs merged

Next Week: • Feature freeze for v1.4 • Security audit • Performance testing

Great work everyone! 🎉

## Post

Send to #engineering and #general

Best Practices

1. Don't Over-Notify

Choose what to notify:

• Critical: Build failures, production issues
• Important: Deploys, PR reviews needed
• Optional: All PR activity, minor updates

Let users configure their preferences.

2. Use Threading

Keep channels clean by using threads:

• Main message: Summary
• Thread: Details, updates, discussion

3. Make Messages Actionable

Every notification should have:

• Clear status indicator
• Relevant context
• Action button (View PR, Fix Build, etc.)

4. Respect Time Zones

Don't notify people outside work hours:

• Check user timezone
• Queue non-urgent notifications
• Mark urgent differently

5. Track Engagement

Monitor if notifications are useful:

• Are people clicking links?
• Are issues getting fixed faster?
• Is the channel noisy?

Summary

Slack integration keeps your team informed without constant context switching. Send updates, request reviews, and coordinate work—all from Claude Code.

Skills Created

Agents Created

Integration Points

• Webhook for simple notifications
• MCP server for full integration
• Agents for automated workflows
• Skills for manual triggers

---

You've now completed the tutorials section! Ready to apply these skills to your own projects? Start with Installing Your First Skill and build from there.