Concepts & Architecture

Before making your first request, understanding these four concepts will prevent most integration questions and errors.

Application

An Application is the main organizational unit within Hub Chatt2.me. It:

• Groups one or more communication channels
• Has its own API Key
• Controls the access scope — a key can only see the channels of its own Application

Think of the Application as your "project" or "product" within the platform.

Channel

A Channel is the connection between your Application and a messaging platform. Examples:

Channel	What it represents
WhatsApp	A phone number connected via the WhatsApp Business API with Meta
Instagram	An Instagram Business account authorized via OAuth (Facebook or Instagram)
Facebook Messenger	A connected Facebook Page
Telegram	A Telegram Bot (via Bot Token)
SMS	An SMS number configured via Twilio
Web Chatt	A first-party web chat widget embedded on your site (configured in Hub)

The from field

In all message-sending endpoints, the from field is the channel UUID:

{
  "from": "6cbd6789-1d2b-47e0-9391-5eb91d2839ea",
  "to": "5511993986082",
  "content": { "text": "Hello!" }
}

This UUID is generated by the platform when you connect the channel. You can find the channel UUID in the Application dashboard, under the Channels section.

tip

Store your channel UUIDs as environment variables in your backend. They do not change unless the channel is disconnected and reconnected.

Message

A Message is the sending payload — what you want to send and to whom. Every message has:

• from — UUID of the sending channel
• to — recipient identifier in the channel
• content — the content (text, image, interactive, etc.)

The to field

The format of to varies by channel:

Channel	Format of to	Example
WhatsApp	E.164 number (without +)	5511993986082
Instagram	IGSID (Instagram user ID)	847495124317323
Messenger	PSID (Messenger conversation ID)	26203292189261166
Telegram	user/group chat_id	8568649397
SMS	E.164 number (with +)	+5511944574999
Web Chatt	Visitor identifier (from webhooks when the visitor messages you)	(per inbound payload)

Web Chatt setup

Connecting the widget and allowed origins are done in the Hub UI. See Web Chatt.

Message status

A send response returns two fields:

{
  "messageId": "9307b9ab-5fab-4151-b7c2-b00c2a8a6e8e",
  "status": "sent"
}

Status	Meaning
sent	The message was successfully sent to the channel (Telegram, Instagram, SMS)
enqueued	The message was received and is in the send queue (WhatsApp, Messenger)
error	Send failed — check errorMessage and errorCode in the response

The messageId can later be used in webhook logs to track delivery status.

Webhook

A Webhook is an HTTP endpoint you register on the platform to receive real-time notifications. There are two event types:

Event	When it fires
Message	When a user sends a message to your channel
MessageStatus	When the delivery status of a message changes (delivered, read)

Without a configured webhook, you can only send messages — not receive them.

Full flow

Your API Key
    │
    ▼
Application (groups channels and defines key scope)
    │
    ├── Channel WhatsApp  (from: uuid-wa)
    ├── Channel Telegram  (from: uuid-tg)
    └── Channel Instagram (from: uuid-ig)
         │
         ▼
    POST /v1/communication/{channel}/message
    { from, to, content }
         │
         ▼
    { messageId, status }
         │
         ▼  (asynchronous, via webhook)
    Your endpoint receives message received / status events