Messaging Extensions Overview

Introduction

Greentic supports multiple messaging platforms through messaging extension packs. Each extension is a WASM pack that handles:

• Ingress - Receiving messages from the platform
• Egress - Sending messages to the platform
• Operations - Platform-specific features such as buttons, cards, threads, file handling, and webhook setup

The current catalog includes Slack, Microsoft Teams, Telegram, WhatsApp, WebChat, WebChat GUI, Webex, and Email messaging packs.

Available Providers

Slack Connect to Slack workspaces with full app support

Microsoft Teams Integrate with Microsoft Teams channels and chats

Telegram Build Telegram bots with buttons and inline keyboards

WhatsApp Connect to WhatsApp Business Platform Cloud API

WebChat Embed chat widget in your website

Webex Integrate with Webex messaging

Email Send and receive emails as messages

Architecture

External Platform (Slack/Teams/Telegram)
    │
    ▼ Webhook
┌─────────────────────────────────────────┐
│           Ingress Component             │
│   (Parse platform-specific format)      │
└─────────────────────────────────────────┘
    │
    ▼ Normalized Message
┌─────────────────────────────────────────┐
│           Runtime Router                │
│  greentic.messaging.ingress.{tenant}... │
└─────────────────────────────────────────┘
    │
    ▼
┌─────────────────────────────────────────┐
│           Flow Executor                  │
│      (Process with your flows)          │
└─────────────────────────────────────────┘
    │
    ▼
┌─────────────────────────────────────────┐
│           Runtime Router                │
│  greentic.messaging.egress.{tenant}...  │
└─────────────────────────────────────────┘
    │
    ▼ Platform-specific format
┌─────────────────────────────────────────┐
│           Egress Component              │
│     (Format for platform API)           │
└─────────────────────────────────────────┘
    │
    ▼ API Call
External Platform

Message Normalization

All providers normalize messages to a common format:

pub struct NormalizedMessage {
    pub id: String,
    pub channel_id: String,
    pub sender_id: String,
    pub sender_name: Option<String>,
    pub content: String,
    pub timestamp: u64,
    pub reply_to: Option<String>,
    pub attachments: Vec<Attachment>,
    pub metadata: Option<Value>,
}

This allows your flows to work across any messaging platform without modification.

Extension Configuration

Messaging extensions are normally selected with gtc wizard, which writes the bundle metadata and pack references for you. The built-in catalog uses OCI references such as:

oci://ghcr.io/greenticai/packs/messaging/messaging-slack:latest
oci://ghcr.io/greenticai/packs/messaging/messaging-teams:latest
oci://ghcr.io/greenticai/packs/messaging/messaging-telegram:latest
oci://ghcr.io/greenticai/packs/messaging/messaging-whatsapp:latest
oci://ghcr.io/greenticai/packs/messaging/messaging-webchat:latest
oci://ghcr.io/greenticai/packs/messaging/messaging-webchat-gui:latest
oci://ghcr.io/greenticai/packs/messaging/messaging-webex:latest
oci://ghcr.io/greenticai/packs/messaging/messaging-email:latest

Setup Answers

Run gtc setup ./my-bundle interactively, or provide an answers file that matches the wizard schema:

answers.json

{
  "messaging-telegram": {
    "enabled": true,
    "public_base_url": "https://example.ngrok-free.app",
    "telegram_bot_token": "123456789:ABCdefGHI..."
  },
  "messaging-slack": {
    "enabled": true,
    "public_base_url": "https://example.ngrok-free.app",
    "slack_bot_token": "xoxb-xxx-xxx",
    "slack_app_id": "A07XXX"
  }
}

Common Features

Text Messages

All providers support basic text messages:

- id: reply
  type: reply
  config:
    message: "Hello! How can I help?"

Rich Content

Most providers support rich content:

- id: send_card
  type: adaptive-card
  config:
    card: "cards/welcome.json"

Buttons/Actions

Interactive elements (provider-dependent):

- id: ask_choice
  type: reply
  config:
    message: "What would you like to do?"
    buttons:
      - label: "Get Help"
        action: "help"
      - label: "Contact Support"
        action: "support"

Attachments

File and media support:

- id: send_file
  type: reply
  config:
    message: "Here's your report"
    attachments:
      - type: file
        url: "https://example.com/report.pdf"
        name: "report.pdf"

Multi-Channel Flows

Write flows that work across channels:

flows/on_message.ygtc

name: universal_handler
version: "1.0"

nodes:
  - id: greet
    type: reply
    config:
      # Works on any platform
      message: "Hello! I'm your assistant."
    to: ask_intent

  - id: ask_intent
    type: reply
    config:
      message: "How can I help you today?"
      # Buttons render differently per platform
      buttons:
        - label: "Get Started"
          action: "start"
        - label: "Help"
          action: "help"

triggers:
  - type: message
    pattern: "hello|hi"
    target: greet

Provider Comparison

Feature	Slack	Teams	Telegram	WhatsApp	WebChat	Webex	Email
Text	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Native rich layout	Block Kit	Adaptive Cards	Inline/reply keyboards	Interactive messages/templates	Adaptive Cards	Adaptive Cards	HTML
Adaptive Card handling	Transformed	Native	Transformed	Transformed	Native	Native subset	Transformed to HTML
Buttons	Yes	Yes	Yes	Yes	Yes	Yes	Links/forms
Files	Yes	Yes	Yes	Yes	Yes	Yes	Attachments
Threads/replies	Threads	Conversations/replies	Reply-to/topics only	No	Conversation history	Threads/spaces	Email headers
Reactions	Platform-dependent	Platform-dependent	No	No	No	No	No

Next Steps

Choose a provider to get started:

• Telegram - Easiest setup, great for testing
• Slack - Full-featured workspace integration
• WebChat - Embed in your website