# smb_app_state_sync webhook reference
This reference describes trigger events and payload contents for the WhatsApp Business account **smb_app_state_sync** webhook.
The **smb_app_state_sync** webhook is used for synchronizing contacts of [WhatsApp Business app users who have been onboarded](https://developers.facebook.com/documentation/business-messaging/whatsapp/embedded-signup/onboarding-business-app-users) via a solution provider.
## Triggers
- A partner [synchronizes the WhatsApp Business app contacts](https://developers.facebook.com/documentation/business-messaging/whatsapp/embedded-signup/onboarding-business-app-users#step-1--initiate-contacts-synchronization) of a business customer with a WhatsApp Business app phone number who the provider has [onboarded](https://developers.facebook.com/documentation/business-messaging/whatsapp/embedded-signup/onboarding-business-app-users).
- A business customer with a WhatsApp Business app phone number who has been [onboarded](https://developers.facebook.com/documentation/business-messaging/whatsapp/embedded-signup/onboarding-business-app-users) by a partner adds a contact to their WhatsApp Business app [contacts](https://faq.whatsapp.com/1270784217226727/).
- A business customer with a WhatsApp Business app phone number who has been [onboarded](https://developers.facebook.com/documentation/business-messaging/whatsapp/embedded-signup/onboarding-business-app-users) by a partner removes a contact from their WhatsApp Business app [contacts](https://faq.whatsapp.com/1270784217226727/).
- A business customer with a WhatsApp Business app phone number who has been [onboarded](https://developers.facebook.com/documentation/business-messaging/whatsapp/embedded-signup/onboarding-business-app-users) by a partner edits a contact in their WhatsApp Business app [contacts](https://faq.whatsapp.com/1270784217226727/).
## Syntax
```html
{
"object": "whatsapp_business_account",
"entry": [
{
"id": "<WHATSAPP_BUSINESS_ACCOUNT_ID>",
"changes": [
{
"value": {
"messaging_product": "whatsapp",
"metadata": {
"display_phone_number": "<BUSINESS_DISPLAY_PHONE_NUMBER>",
"phone_number_id": "<BUSINESS_PHONE_NUMBER_ID>"
},
"state_sync": [
{
"type": "contact",
"contact": {
"full_name": "<CONTACT_FULL_NAME>",
"first_name": "<CONTACT_FIRST_NAME>",
"phone_number": "<CONTACT_PHONE_NUMBER>"
},
"action": "<ACTION>",
"metadata": {
"timestamp": "<WEBHOOK_TRIGGER_TIMESTAMP>"
}
},
<!-- Additional contacts would follow, if any -->
]
},
"field": "smb_app_state_sync"
}
]
}
]
}
```
## Parameters
| Placeholder | Description | Example value |
| --- | --- | --- |
| `<ACTION>`<br><br>_String_ | Indicates if the business customer added, edited, or deleted a contact from their WhatsApp Business app phone address book.<br><br>Values can be:<br><br>`add` — Indicates the WhatsApp Business app user added or edited a contact.<br><br>`remove` — Indicates the WhatsApp Business app user removed a contact. | `add` |
| `<BUSINESS_DISPLAY_PHONE_NUMBER>`<br><br>_String_ | Business display phone number. | `15550783881` |
| `<BUSINESS_PHONE_NUMBER_ID>`<br><br>_String_ | Business phone number ID. | `106540352242922` |
| `<CONTACT_FIRST_NAME>`<br><br>_String_ | The contact's first name, as it appears in the business customer's WhatsApp Business app phone address book.<br><br>Not included when the business customer removes a contact from their WhatsApp Business app phone address book. | `Pablo` |
| `<CONTACT_FULL_NAME>`<br><br>_String_ | The contact's full name, as it appears in the business customer's WhatsApp Business app phone address book.<br><br>Not included when the business customer removes a contact from their WhatsApp Business app phone address book. | `Pablo Morales` |
| `<CONTACT_PHONE_NUMBER>`<br>_String_ | The contact's WhatsApp phone number. | `16505551234` |
| `<WEBHOOK_TRIGGER_TIMESTAMP>`<br><br>_Integer_ | Unix timestamp indicating when the webhook was triggered. | `1739321024` |
| `<WHATSAPP_BUSINESS_ACCOUNT_ID>`<br><br>_String_ | WhatsApp Business Account ID. | `102290129340398` |
## Example
```json
{
"object": "whatsapp_business_account",
"entry": [
{
"id": "102290129340398",
"changes": [
{
"value": {
"messaging_product": "whatsapp",
"metadata": {
"display_phone_number": "15550783881",
"phone_number_id": "106540352242922"
},
"state_sync": [
{
"type": "contact",
"contact": {
"full_name": "Pablo Morales",
"first_name": "Pablo",
"phone_number": "16505551234"
},
"action": "add",
"metadata": {
"timestamp": "1739321024"
}
}
]
},
"field": "smb_app_state_sync"
}
]
}
]
}
```