# "How to Connect TwiML Rest API to On-Chat"

> "On-Chat integrates with TwiML Rest API so your team can receive and respond to inbound SMS from Twilio-powered numbers in a centralized inbox with routing, automation, and conversation tracking."

URL: https://on-chat.live/guides/how-to-connect-twiml-rest-api-to-on-chat/
Last updated: 2026-11-14

## Introduction
TwiML (Twilio Markup Language) Rest API is Twilio's programmable messaging interface that allows developers to control how SMS messages are sent, received, and responded to using XML-based instructions. By integrating the TwiML Rest API channel with On-Chat, support teams can receive inbound SMS through Twilio-powered numbers, manage conversations in a shared inbox, and leverage On-Chat's routing and automation features for structured, responsive customer support.

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## Prerequisites
- An active Twilio account with a phone number enabled for SMS
- Twilio Account SID and Auth Token from the Twilio console
- Basic understanding of TwiML and Twilio webhooks
- On-Chat account with admin access
- Ability to configure the SMS webhook URL on your Twilio phone number

## Step 1: Retrieve Your Twilio Account SID and Auth Token
Log in to the Twilio console at console.twilio.com. On the dashboard, copy your **Account SID** and **Auth Token**. These are used to authenticate On-Chat's API requests to Twilio. Keep these credentials secure and do not share them publicly.

## Step 2: Identify Your Twilio Phone Number
In the Twilio console, go to **Phone Numbers** → **Manage** → **Active Numbers** and select the number you want to use for SMS customer support. Note the full E.164 formatted number. Confirm the number has the SMS capability enabled.

## Step 3: Create a TwiML SMS Inbox in On-Chat
In On-Chat, go to **Settings** → **Inboxes** → **New Inbox** and select **SMS**. Choose **TwiML Rest API** as the provider. Enter your Twilio Account SID, Auth Token, and phone number. Save the inbox — On-Chat will generate the inbound webhook URL for your Twilio number.

## Step 4: Configure the Webhook URL in Twilio
In the Twilio console, navigate to your phone number's configuration. Under **Messaging**, set the **A Message Comes In** webhook URL to the On-Chat webhook URL you generated. Set the method to HTTP POST. Save the configuration. Twilio will now forward all inbound SMS to On-Chat.

## Step 5: Add Agents and Configure Routing
In On-Chat, go to **Settings** → **Inboxes** → select your TwiML inbox → **Collaborators**. Add agents to handle SMS conversations. Enable auto-assignment to route new conversations to available agents based on workload or round-robin distribution.

## Step 6: Test the Full Message Flow
Send a test SMS to your Twilio number. Confirm it appears as a new conversation in On-Chat. Reply from an agent and verify the customer receives the outbound SMS via Twilio. Review Twilio's message logs and On-Chat's conversation history to confirm everything is working end-to-end.

## Best Practices
- Use On-Chat automation to send immediate auto-acknowledgment messages when customers first contact via your Twilio TwiML number
- Monitor Twilio's message delivery logs to track outbound SMS success and troubleshoot failed deliveries
- Apply On-Chat conversation labels to categorize TwiML SMS issues by type, region, or product
- Use Twilio's error webhooks to alert your team when SMS delivery fails so no customer message is missed

## Keep reading

- [How to Build a WhatsApp Chatbot Without Code](https://on-chat.live/guides/how-to-build-a-whatsapp-chatbot/): A step-by-step tutorial for building a dynamic WhatsApp chatbot in a visual flow builder, from your first message to live data and agent handoff.
- [Chatbot Flow Design: 12 Best Practices](https://on-chat.live/guides/chatbot-flow-design-best-practices/): Practical rules for designing chatbot conversation flows that customers finish: branching, fallbacks, personalisation, handoff and testing.
- [Make Your Chatbot Dynamic with Webhooks](https://on-chat.live/guides/dynamic-chatbot-webhooks/): Connect your chatbot flows to live data. Learn how webhooks, expressions and splits turn a scripted bot into one that answers with real information.