# smb_app_state_sync webhook reference | Developer Documentation

<div id="bkmrk-smb_app_state_sync-w">## smb\_app\_state\_sync webhook reference

<div><span>Updated: Oct 22, 2025</span></div><div>This reference describes trigger events and payload contents for the WhatsApp Business Account **smb\_app\_state\_sync** webhook.</div><div>The **smb\_app\_state\_sync** webhook is used for synchronizing contacts of [WhatsApp Business app users who have been onboarded](/books/meta-whatsapp/page/onboarding-whatsapp-business-app-users-aka-coexistence-developer-documentation) via a solution provider.</div><div id="bkmrk-triggers"><div id="bkmrk-triggers-1"><div>### Triggers

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<span>A solution provider [synchronizes the WhatsApp Business app contacts](/books/meta-whatsapp/page/onboarding-whatsapp-business-app-users-aka-coexistence-developer-documentation) of a business customer with a WhatsApp Business app phone number who the provider has [onboarded](/books/meta-whatsapp/page/onboarding-whatsapp-business-app-users-aka-coexistence-developer-documentation).</span><span>A business customer with a WhatsApp Business app phone number who has been [onboarded](/books/meta-whatsapp/page/onboarding-whatsapp-business-app-users-aka-coexistence-developer-documentation) by a solution provider adds a contact to their WhatsApp Business app [contacts<span>?</span>](https://l.facebook.com/l.php?u=https%3A%2F%2Ffaq.whatsapp.com%2F1270784217226727%2F&h=AT7I_zLMvA5AxvrOgcBrvDnDyrmucqjOfPoBz62cGqv8nsyZziJ51E7WOS8rsUFIRX1yKkhozxChco15aT-zRGulcVxDgHgFMon6uydCciH0Pu3q3JOerXz3vz50N1ekOSyin8XHV-f53KI5nLANDw).</span><span>A business customer with a WhatsApp Business app phone number who has been [onboarded](/books/meta-whatsapp/page/onboarding-whatsapp-business-app-users-aka-coexistence-developer-documentation) by a solution provider removes a contact from their WhatsApp Business app [contacts<span>?</span>](https://l.facebook.com/l.php?u=https%3A%2F%2Ffaq.whatsapp.com%2F1270784217226727%2F&h=AT7I_zLMvA5AxvrOgcBrvDnDyrmucqjOfPoBz62cGqv8nsyZziJ51E7WOS8rsUFIRX1yKkhozxChco15aT-zRGulcVxDgHgFMon6uydCciH0Pu3q3JOerXz3vz50N1ekOSyin8XHV-f53KI5nLANDw).</span><span>A business customer with a WhatsApp Business app phone number who has been [onboarded](/books/meta-whatsapp/page/onboarding-whatsapp-business-app-users-aka-coexistence-developer-documentation) by a solution provider edits a contact in their WhatsApp Business app [contacts<span>?</span>](https://l.facebook.com/l.php?u=https%3A%2F%2Ffaq.whatsapp.com%2F1270784217226727%2F&h=AT7I_zLMvA5AxvrOgcBrvDnDyrmucqjOfPoBz62cGqv8nsyZziJ51E7WOS8rsUFIRX1yKkhozxChco15aT-zRGulcVxDgHgFMon6uydCciH0Pu3q3JOerXz3vz50N1ekOSyin8XHV-f53KI5nLANDw).</span><div id="bkmrk-parameters"><div id="bkmrk-parameters-1"><div>### Parameters

</div></div></div><div><table><thead><tr><th><span>Placeholder </span></th><th><span>Description </span></th><th><span>Example value </span></th></tr></thead><tbody><tr><td><div><div>`<ACTION>`</div><div>*String*</div></div></td><td><div><div>Indicates if the business customer added, edited, or deleted a contact from their WhatsApp Business app phone address book.</div><div>Values can be:</div><div>`add` - Indicates the WhatsApp Business app user added or edited a contact.</div><div>`remove` - Indicates the WhatsApp Business app user removed a contact.</div></div></td><td><div><div>`add`</div></div></td></tr><tr><td><div><div>`<BUSINESS_DISPLAY_PHONE_NUMBER>`</div><div>*String*</div></div></td><td><div><div>Business display phone number.</div></div></td><td><div><div>`15550783881`</div></div></td></tr><tr><td><div><div>`<BUSINESS_PHONE_NUMBER_ID>`</div><div>*String*</div></div></td><td><div><div>Business phone number ID.</div></div></td><td><div><div>`106540352242922`</div></div></td></tr><tr><td><div><div>`<CONTACT_FIRST_NAME>`</div><div>*String*</div></div></td><td><div><div>The contact's first name, as it appears in the business customer's WhatsApp Business app phone address book.</div><div>Not included when the business customer removes a contact from their WhatsApp Business app phone address book.</div></div></td><td><div><div>`Pablo`</div></div></td></tr><tr><td><div><div>`<CONTACT_FULL_NAME>`</div><div>*String*</div></div></td><td><div><div>The contact's full name, as it appears in the business customer's WhatsApp Business app phone address book.</div><div>Not included when the business customer removes a contact from their WhatsApp Business app phone address book.</div></div></td><td><div><div>`Pablo Morales`</div></div></td></tr><tr><td><div><div>`<CONTACT_PHONE_NUMBER>`*String*</div></div></td><td><div><div>The contact's WhatsApp phone number.</div></div></td><td><div><div>`16505551234`</div></div></td></tr><tr><td><div><div>`<WEBHOOK_TRIGGER_TIMESTAMP>`</div><div>*Integer*</div></div></td><td><div><div>Unix timestamp indicating when the webhook was triggered.</div></div></td><td><div><div>`1739321024`</div></div></td></tr><tr><td><div><div>`<WHATSAPP_BUSINESS_ACCOUNT_ID>`</div><div>*String*</div></div></td><td><div><div>WhatsApp Business Account ID.</div></div></td><td><div><div>`102290129340398`</div></div></td></tr></tbody></table>

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