Skip to main content
Build a CI/CD alert channel that forwards deploy events into Claude Code, then upgrade it to a two-way service connector with replay support. By the end, you’ll understand how channels work end-to-end.
Prerequisites: A FrontMCP project initialized (see Installation). Channels require @frontmcp/sdk >= 1.0.0.

​
What You’ll Build

  1. A webhook channel that receives deploy events and pushes them to Claude Code
  2. Upgrade to a two-way channel where Claude can reply
  3. Add a service connector with outbound tools
  4. Add replay buffering for offline sessions

​
Step 1: Create the Channel

Create src/apps/devops/channels/deploy.channel.ts: 
import { Channel, ChannelContext } from '@frontmcp/sdk';
import type { ChannelNotification } from '@frontmcp/sdk';

@Channel({
  name: 'deploy-alerts',
  description: 'CI/CD deployment status notifications',
  source: { type: 'webhook', path: '/hooks/deploy' },
  meta: { team: 'platform' },
})
export class DeployChannel extends ChannelContext {
  async onEvent(payload: unknown): Promise<ChannelNotification> {
    const { body } = payload as { body: { status: string; version: string; env: string } };
    return {
      content: `Deploy ${body.status}: ${body.version} to ${body.env}`,
      meta: { status: body.status, version: body.version, env: body.env },
    };
  }
}
Key concepts:
PartPurpose
@Channel()Declares metadata — name, source, static meta
ChannelContextBase class providing logger, DI, and lifecycle hooks
onEvent()Inbound handler — receives external events, returns a notification for Claude
source: { type: 'webhook', path: '...' }Registers an HTTP POST endpoint
metaStatic key-value pairs added to every notification

​
Step 2: Register in an App

Create src/apps/devops/index.ts: 
import { App } from '@frontmcp/sdk';
import { DeployChannel } from './channels/deploy.channel';

@App({
  name: 'DevOps',
  description: 'CI/CD and deployment monitoring',
  channels: [DeployChannel],
})
export class DevOpsApp {}

​
Step 3: Enable Channels in Server

Update src/main.ts: 
import { FrontMcp } from '@frontmcp/sdk';
import { DevOpsApp } from './apps/devops';

@FrontMcp({
  info: { name: 'my-server', version: '1.0.0' },
  apps: [DevOpsApp],
  channels: { enabled: true },
})
export default class Server {}
Channels must be explicitly enabled with channels: { enabled: true }. Without this, channel declarations are ignored.

​
Step 4: Test It

Write an E2E test using createDirect(): 
import { FrontMcpInstance, DirectMcpServer } from '@frontmcp/sdk';

describe('Deploy Channel', () => {
  let server: DirectMcpServer;

  beforeEach(async () => {
    server = await FrontMcpInstance.createDirect({
      info: { name: 'test', version: '0.0.1' },
      apps: [DevOpsApp],
      auth: { mode: 'public' },
      channels: { enabled: true },
    });
  });

  afterEach(async () => {
    await server.dispose();
  });

  it('should register the channel', async () => {
    const tools = await server.listTools();
    // No tools from this channel (it's one-way, no reply tool needed)
    expect(tools).toBeDefined();
  });
});
When Claude Code connects to this server, it will see events as: 
<channel source="deploy-alerts" team="platform" status="success" version="1.2.3" env="production">
Deploy success: 1.2.3 to production
</channel>

​
Step 5: Add Two-Way Support

Make it so Claude can reply to deploy events (e.g., to trigger a rollback): 
@Channel({
  name: 'deploy-alerts',
  description: 'CI/CD notifications. Reply to trigger actions.',
  source: { type: 'webhook', path: '/hooks/deploy' },
  twoWay: true,  // Enables the channel-reply tool
  meta: { team: 'platform' },
})
export class DeployChannel extends ChannelContext {
  async onEvent(payload: unknown): Promise<ChannelNotification> {
    // ... same as before
  }

  async onReply(reply: string, meta?: Record<string, string>): Promise<void> {
    // Claude replied — forward to Slack, trigger rollback, etc.
    console.log(`Claude says: ${reply}`);
    if (reply.toLowerCase().includes('rollback')) {
      await triggerRollback(meta?.version);
    }
  }
}
Setting twoWay: true auto-registers a channel-reply tool. Claude can now call: 
channel-reply({ channel_name: "deploy-alerts", text: "Rollback to v1.2.2", meta: { version: "1.2.2" } })

​
Step 6: Upgrade to Service Connector

For full bidirectional messaging (like WhatsApp), use a service connector with contributed tools: 
import { Tool, ToolContext } from '@frontmcp/sdk';
import { z } from '@frontmcp/sdk';

// Outbound tool — Claude calls this to send messages
@Tool({
  name: 'send-deploy-command',
  description: 'Send a deploy command to the CD system',
  inputSchema: {
    env: z.enum(['staging', 'production']),
    version: z.string(),
  },
})
class SendDeployCommand extends ToolContext {
  async execute(input: { env: string; version: string }) {
    // Call CD API to trigger deploy
    return { triggered: true, env: input.env, version: input.version };
  }
}

// Upgrade the channel to service connector
@Channel({
  name: 'deploy-service',
  description: 'Bidirectional deploy service. Send commands and receive status.',
  source: { type: 'service', service: 'deploy-pipeline' },
  tools: [SendDeployCommand],  // Auto-registered in tool list
  twoWay: true,
})
export class DeployServiceChannel extends ChannelContext {
  async onConnect(): Promise<void> {
    // Start listening to deploy pipeline events
    this.logger.info('Connected to deploy pipeline');
  }

  async onEvent(payload: unknown): Promise<ChannelNotification> {
    const event = payload as { status: string; version: string };
    return { content: `Deploy ${event.status}: ${event.version}` };
  }
}

​
Step 7: Add Replay Buffer

Events that arrive while Claude is offline can be buffered and replayed: 
@Channel({
  name: 'deploy-alerts',
  source: { type: 'webhook', path: '/hooks/deploy' },
  replay: {
    enabled: true,
    maxEvents: 50,  // Ring buffer, oldest evicted
  },
})
export class DeployChannel extends ChannelContext {
  async onEvent(payload: unknown): Promise<ChannelNotification> {
    // ... same as before
  }
}
When a new Claude Code session connects, buffered events can be replayed. Replayed events include replayed: "true" in their meta so Claude can distinguish them from live events.

​
Next Steps

Channels Reference

Full channels documentation with all 7 source types

@Channel API

Complete decorator and configuration reference