RCS Webhook Overview

Fast2SMS can send real-time RCS delivery updates and incoming customer messages as a POST request (JSON or URL-encoded) or GET request to your configured webhook URL.

Webhook Formats

When creating a webhook, you can select one of the following formats under Select Format:

Standard Webhook (custom): Fully customizable. Allows configuration of Select Event, Method, Content-Type, and Body (payload). X-Payload-Transform is shown only when Content-Type is Form URL Encoded.
CleverTap (RCS) (clevertap_rcs): Integrates directly with CleverTap's webhook callback structure. Select Event, Method, Content-Type, and Body are locked (read-only) when this template is selected.

Webhook Panel Form Options

When configuring a webhook in the Fast2SMS Dashboard under CREATE WEBHOOK, the fields correspond to the API parameters as follows:

Field Label in UI	API Parameter	Description & Visibility Rules
Webhook Name	`name`	Friendly name for internal tracking.
Select Service	`service`	Choose `RCS` to configure RCS webhooks.
Select Format	`template`	Choose `Standard Webhook` or `CleverTap (RCS)`.
Select Event	`event`	Filter trigger events (e.g. `Default All Events`, `On Sent`, `On Delivered`, `On Read`, `On Failed`, `Incoming Messages`). Locked if format is not Standard Webhook.
Bot Id	`identity_id`	Optional RCS Bot ID. Defaults to "Default All". Only shown when Service is RCS.
Method	`method`	HTTP method (`POST`, `GET`, `PUT`). Locked if format is not Standard Webhook.
URL	`url`	Destination URL to receive payloads.
Content-Type	`content_type`	Target encoding format (`JSON`, `Form URL Encoded`, `XML`). Locked if format is not Standard Webhook.
X-Payload-Transform	`payload_transform`	Transform level (`Standard`, `Raw JSON`). Shown only when Content-Type is Form URL Encoded.
Webhook Status (Active)	`status`	Switch to enable/disable webhook triggers (`active`/`inactive`).
Body	`payload`	Custom payload structure text. Locked if format is not Standard Webhook.

Standard Webhook Payload

Payload Variables

Variable	Type	Description
`request_id`	String	Unique request identifier for the message
`route`	String	The service route (e.g., `response` or `rcs`)
`sender_id`	String	The Sender ID / Bot ID
`delivery_attempt`	Integer	Number of delivery attempts
`character_count`	Integer	Character count of the message text
`mobile`	String	Recipient 10-digit mobile number
`status`	String	Delivery status (e.g., `delivered`, `failed`, `received`)
`status_description`	String	Detailed status text
`udf1`	String	User Defined Field 1 – Optional custom value passed via API and returned in the webhook for your internal reference or tracking.
`udf2`	String	User Defined Field 2 – Optional custom value passed via API and returned in the webhook for your internal reference or tracking.
`udf3`	String	User Defined Field 3 – Optional custom value passed via API and returned in the webhook for your internal reference or tracking.
`bot_id`	String	RCS Bot identifier
`error_message`	String	Details of the error if delivery failed
`from`	String	Sender phone number (for incoming messages)
`message_type`	String	Message type (e.g., `text`)
`body`	String	Message text body (for incoming messages)
`post_attempt`	Integer	Webhook retry attempt count
`webhook_type`	String	Event type (e.g., `status_update`, `incoming_message`)
`ts`	String	Unix timestamp reference
`failure_reason`	String	Failure reason description
`description`	String	Event status overview
`mime_type`	String	MIME type for media
`media_url`	String	URL to media files
`caption`	String	Caption for media messages
`timestamp`	Integer	Timestamp of the event

Example JSON Payload (Status Update)

{
  "request_id": "Rabcdef12345678",
  "route": "response",
  "sender_id": "GLOBAL",
  "delivery_attempt": 1,
  "character_count": 120,
  "mobile": "9999999999",
  "status": "delivered",
  "status_description": "Delivered successfully",
  "udf1": "TEST-CLIENT-ID",
  "udf2": "TEST-CRQID",
  "udf3": "TEST-UUID-1234",
  "bot_id": "test_rcs_bot",
  "error_message": "Test error message",
  "post_attempt": 1,
  "webhook_type": "status_update",
  "ts": "1718712002",
  "failure_reason": "",
  "description": "Delivered successfully",
  "timestamp": 1718712002
}

CleverTap (RCS) Webhook Payload

If you select the CleverTap (RCS) format, the payload will be structured as follows:

Example JSON Payload (CleverTap RCS)

{
  "payloadVersion": "1",
  "statuses": [
    {
      "msgId": "Rabcdef12345678",
      "status": "delivered",
      "timestamp": "1718712002",
      "description": "Delivered successfully"
    }
  ]
}