Apple Business Chat
Apple Business Chat is a channel built to reach customers through Messages on any Apple device. The channel prides itself on its rich set of messaging features including bot and AI capabilities, security, and ability to connect to the wide world of iOS apps and add-ons.
Channel overview
Apple Business Chat is used for customer service interactions, scheduling tasks, and even payments. This means that customers interact with brands as easily as they message their friends and family. It’s discoverable from Apple Maps, Safari, and Search— or directly embedded into a brand’s website.
Accounts
Apple Business Register
Apple Business Chat requires all businesses to register with Apple before rolling out Business Chat. A business will need to submit brand information, including addresses and logos, for Apple’s approval. As part of this process, you’ll be prompted to select a Messaging Service Provider. Here is where Zendesk’s Sunshine Conversations comes into play— as a Messaging Service Provider, we are certified by Apple to provide services and solutions for your Business Chat needs. At the end of the registration process, you’ll receive a unique Business Chat ID that will be used to connect to Sunshine Conversations
Setting up a Business Chat Account
There are 4 steps to complete your Business Chat Account in the Apple Business Register:
-
Sign into the Business Register and add a Business Chat Account
-
Go to register.apple.com
- Select sign in with your Apple ID
- Log in with your Apple ID. If you don’t have one, you’ll need to create one
- Accept the Terms & Conditions to continue
-
You’ll be directed to a Manage Services page
- Add the Business Accounts for Messages and click Done at the bottom of the page
-
Click on Business Chat Accounts
- Select Add New
- Click on Get Started
- Select Add New
-
You’ll need to provide
- Business Chat Account applicant details
- Account type (e.g. “Commercial”)
- Technical contact
-
Fill in your Brand Identity details
- These are your square and wide logos, plus branding colors
-
Complete your Brand Information Card
- These details include your brand name, website, phone number, message response time, live agent response hours. This will be shown to customers in Messages.
-
Select Zendesk- Sunshine Conversations as your Messaging Service Provider
- Start typing Zendesk and use the auto-complete to find us
-
Finally, click Send for review to submit your application to Apple. You’ll be able to see the status of your application at the top of your Business Chat Account page.
Business Chat ID
After you’ve been approved by Apple for Business Chat, you’ll be issued a Business Chat ID.
You can find the Business Chat ID by going to your Business Chat Account page and scrolling down to the Messaging Service Provider section.
From there, click on Test your Messaging Service Provider connection.
After that, you’ll be directed to a page where you can copy your Business Chat ID.
Capabilities
Apple supports a wide variety of capabilities as seen in the channel capabilities grid. Below is a detailed view of each capability.
Content Types
Action Types
Structured Messages
Indicators
Delivery Events
Delivery events allow you to track deliveries of Sunshine Conversations messages to Apple Business Chat by subscribing to the conversation:message:delivery:channel webhook. Failures to deliver a message to Apple Business Chat can be detected by subscribing to the conversation:message:delivery:failure webhook.
Embed the Apple Business Chat Button
Apple’s documentation can be found here.
You will need to do the following:
- Add Apple’s Business Chat JS (javascript) library to your webpage headers
- Add a
<div>container to house the button - Customize the banner, fallback support, and button colour to meet your brand’s needs
The Business Chat button must contain the following, at minimum:
- A class attribute to specify the type of container: banner, phone, or message. For more information, see Business Chat Button Class and Data Attributes.
- A
data-apple-business-idattribute with the business ID you received when you registered your company with Business Chat.
How to enable the channel
Using the Dashboard
If you don’t have a Sunshine Conversations account yet, contact us from the Test your Messaging Service Provider connection in the Business Register to continue the integration process. From that page, you can click on the Connect button to send you to the Sunshine Conversations site.
-
Log into the Apple Business Register
-
In a separate tab, log into your Sunshine Conversations Dashboard
-
Copy your Business Chat ID from the Test your Messaging Service Provider connection page in Apple Business Register
-
In the Sunshine Conversations Dashboard, select ABC from the list of channel integrations
-
Next, complete the following steps to connect your ABC integration
- Choose a name for this integration so you can find it easily within your Sunshine Conversations app
- Paste your Business Chat ID
- Click Connect
Security and Business Chat IDs
Since Business Chat IDs are public, Sunshine Conversations has implemented a security measure to ensure your brand’s Business Chat ID stays linked to your Sunshine Conversations app. This means that a Business Chat ID cannot be migrated from one app to another through the dashboard or API. If you need to remove your Apple Business Chat integration and migrate it to another app, please contact our team for assistance using the help widget in your dashboard. Our team will release the Business Chat ID on your behalf.
Using the integration API as an MSP
There are 3 different IDs required in the payload:
- MSP ID, a unique identifier for an ABC partner registered as a Messaging Service Provider through Apple Business Register
- API secret, a key tied to the MSP
- Business Chat ID, tied to the brand using ABC
Tracking customer intent
Apple makes it possible to publish a URL for users to tap that will bring them into iMessage to chat with the business.
In order to provide some context to the business about which link was clicked by the user, the biz-intent-id and biz-group-id parameters can be included as querystring parameters on the URL:
https://bcrw.apple.com/urn:biz:{businessId}?biz-intent-id=TestingBizIntent&biz-group-id=TestingBizGroup
Group and intent are both optional. If both are left unspecified, the client.raw object will be absent and the message.source.group and message.source.intent fields will be absent.
Whenever Sunshine Conversations receives a group or intent attached to an Apple Business Chat message, these values will be exposed in both the Sunshine Conversations message and client objects. For example, after a user clicks on such a link, the first message received by that user will trigger a message:appUser webhook like this:
{
"trigger": "message:appUser",
"app": { "_id": "599349ff5f753aecf2e151c9" },
"messages": [
{
"authorId": "caf1dbe12cee751407bd53a6",
"received": 1512587862.523,
"type": "text",
"text": "Hi",
"name": "Glass Chameleon",
"role": "appUser",
"_id": "5a284256fbbc83ffb792e31c",
"source": {
"type": "apple",
"group": "TestingBizGroup",
"intent": "TestingBizIntent"
}
}
],
"appUser": {
"_id": "caf1dbe12cee751407bd53a6",
"signedUpAt": "2017-12-06T16:59:11.355Z",
"conversationStarted": true,
"credentialRequired": true,
"clients": [
{
"raw": {
"group": "TestingBizGroup",
"intent": "TestingBizIntent"
},
"id": "1da8d244-a389-4240-ae6e-4b6975c88236",
"platform": "apple",
"linkedAt": "2017-12-06T16:59:11.357Z",
"lastSeen": "2017-12-06T19:17:42.476Z",
"active": true,
"primary": true
}
]
}
}
Client object
Any group or intent received from Apple will be persisted in the client object. Each subsequent message:appUser webhook payload will include those fields.
Message object
The last known group or intent will also be included under the message.source, and will be replayed in future messages coming from that user so long as neither changes.
Clients and messages can also be retrieved at a later date via the user API and messages API respectively.
Changing group or intent
A user can click a different business chat link with different biz-* query parameters, thus changing the conversation’s group and intent. In this case, client.raw.group and client.raw.intent will be individually updated with any new values. Group and intent values that were received with previous messages will still be preserved in the message history under that message’s source.group and source.intent parameters.
Unsubscribe
If a user unsubscribes, the group and intent stored on the client will be cleared. If they later change their mind and send a new message to the business (without having clicked a business chat link with query parameters) these parameters will be absent from the smooch client.
Passthrough API
The passthrough API is a way to send message types for which there is no corresponding Sunshine Conversations type or to leverage channel-specific features not folded into the Sunshine Conversations API (e.g. Apple list or time pickers.) To accomplish this, the developer provides Sunshine Conversations with the raw payload to send to the messaging provider’s API, and the Sunshine Conversations platform will “pass it through”.
To use the passthrough API, you first craft a valid Sunshine Conversations message of any type, then you specify an additional override parameter for the channels you would like to use passthrough. Under the channel name (in this case abc), the payload field contains the exact structure of a valid Apple Business Chat Service API call to the Message endpoint.
The passthrough API described below has been introduced so that it’s possible to send any message type to Apple Business Chat.
While the passthrough API accepts payloads up to 100kb, building Business Chat messages often result in payloads larger than 100kb. For instance, when sending a list picker with an image associated with each item, those images must be directly included inside the payload (using base64 encoding). To get past this limitation, Sunshine Conversations exposes new large message and large template APIs that handle payloads up to 10mb.
We recommend using templates where possible, to avoid crafting complex messages each time they’re sent and also to avoid network delays when sending large messages.
Using the passthrough API
To use the passthrough API, you first craft a valid message of any type, then you specify an additional override parameter for the channels you would like to use passthrough.
Example:
{
"role": "appMaker",
"text": "Hello there",
"type": "text",
"override": {
"apple": {
"payload": {
"body": "goodbye",
"type": "text"
}
}
}
}
The above example depicts a simple override example, where the text message will render as “Hello there” on every channel except Apple, where it would render as “goodbye”. Note that type and body are Apple-specific fields, exactly as the Apple API would accept them.
Business Chat requires images (aka large interactive data) to be embedded as base64 strings inside message JSON payloads. This tends to make JSON payloads large. However, our standard /messages API only supports payloads up to 100kb. We provide a large message and large template API to support payloads up to 10mb.
Reserved fields
In order to ensure the message is correctly delivered, Sunshine Conversations will automatically set some fields in the payload for you. If you supply these fields, they will be ignored and replaced:
| Reserved Key | Reserved Behaviour |
|---|---|
v | Specifies the version of the message schema to use. Sunshine Conversations will automatically set this to 1 |
id | A unique identifier (in UUID format) for the message. Sunshine Conversations will automatically generate and populate this value |
sourceId | The unique identifier of the calling business. Sunshine Conversations will populate this value based on the configured integration |
destinationId | The unique identifier of the user. Sunshine Conversations will populate this value based on the target user |
Sending Apple messages
Rich Links
Rich links can contain an image or video preview. For the image, you must provide the image in Base64 encoding. You can obtain this through a library or 3rd party website.
Please note that considering the size of the payload with the base64 image, you will need to use the following endpoint to send a message:
POST v1/apps/{appId}/appusers/{appUserId}/messages/large
Example of a rich link with an image preview:
{
"role": "appMaker",
"type": "text",
"text": "Hello there!",
"override": {
"apple": {
"payload": {
"body": "https://smooch.io/",
"type": "richLink",
"richLinkData": {
"url": "https://smooch.io/",
"title": "Title",
"assets": {
"image": {
"data": "put base64 encoded image here",
"mimeType": "image/jpg"
}
}
}
}
}
}
}
Example of a Rich link with a video preview:
{
"role": "appMaker",
"type": "text",
"text": "Hello there",
"override": {
"apple": {
"payload": {
"body": "https://smooch.io/",
"type": "richLink",
"richLinkData": {
"url": "https://smooch.io/",
"title": "Title",
"assets": {
"video": {
"url": "https://images.apple.com/media/us/homepod/2018/98e6cc1a_37ec_4e69_b717_9e58c71e1937/films/expand/homepod-expand-tpl-cc-us-20180306_1280x720h.mp4",
"mimeType": "video/mp4"
}
}
}
}
}
}
}
Attachments
For some message types, it might be necessary to send attachments. In such cases, you should refer to the Apple documentation for instructions on how to upload those resources to Apple, and pass the object reference to Sunshine Conversations using the passthrough API.
Example:
{
"role": "appMaker",
"text": "Hello there",
"type": "image",
"mediaType": "image/png",
"mediaUrl": "https://marketplace-cdn.smooch.io/apple/icon.png",
"override": {
"apple": {
"payload": {
"attachments": [
{
"decryption-key": "00260450bb05cd4597a8ae706199f685c0f6fafee4b6c3e1375771c472f4149e29",
"file-size": "10159",
"mime-type": "image/png",
"mmcs-owner": "M39303332653438322d396338342d313165372d613330332d633735336231626666366661.C01USN00",
"mmcs-signature-base64": "AXG58GIo7xWZz7gRXZH2liWuzVah",
"mmcs-url": "https://p97-content.icloud.com",
"name": "icon.png"
}
],
"body": "goodbye \ufffc",
"type": "text"
}
}
}
}
List picker
A sample list picker payload sent through the passthrough API:
{
"role": "appMaker",
"text": "Hello there",
"override": {
"apple": {
"payload": {
"interactiveData": {
"bid": "com.apple.messages.MSMessageExtensionBalloonPlugin:0000000000:com.apple.icloud.apps.messages.business.extension",
"data": {
"images": [],
"listPicker": {
"multipleSelection": true,
"sections": [
{
"items": [
{
"identifier": "taco-appetizer",
"order": 0,
"style": "default",
"subtitle": "Great tacos",
"title": "Tacos"
},
{
"identifier": "burrito-appetizer",
"order": 1,
"style": "default",
"subtitle": "Good burritos",
"title": "Burritos"
}
],
"order": 0,
"title": "Appetizers"
},
{
"items": [
{
"identifier": "taco-meal",
"order": 0,
"style": "default",
"subtitle": "Great tacos",
"title": "Tacos"
},
{
"identifier": "burrito-meal",
"order": 1,
"style": "default",
"subtitle": "Good burritos",
"title": "Burritos"
}
],
"order": 1,
"title": "Meals"
}
]
},
"mspVersion": "1.0",
"requestIdentifier": "food-picker-1"
},
"receivedMessage": {
"style": "small",
"subtitle": "Let's eat!",
"title": "FoodPicker"
},
"replyMessage": {
"style": "large",
"subtitle": "Nutrition",
"title": "Selected food"
}
},
"type": "interactive"
}
}
}
}
Time picker
A sample time picker payload sent through the passthrough API:
{
"role": "appMaker",
"text": "Hello there",
"override": {
"apple": {
"payload": {
"interactiveData": {
"bid": "com.apple.messages.MSMessageExtensionBalloonPlugin:0000000000:com.apple.icloud.apps.messages.business.extension",
"data": {
"event": {
"identifier": "reservation-id",
"timeslots": [
{x
"duration": 3600,
"identifier": "7-am",
"startTime": "2018-10-24T07:00+0000"
},
{
"duration": 3600,
"identifier": "8-am",
"startTime": "2018-10-24T08:00+0000"
}
],
"timezoneOffset": 400,
"title": "Available Reservations"
},
"mspVersion": "1.0",
"requestIdentifier": "appointment-selector-1"
},
"receivedMessage": {
"style": "icon",
"title": "Make a reservation"
},
"replyMessage": {
"style": "icon",
"title": "Your reservation"
}
},
"type": "interactive"
}
}
}
}
Custom extension
A sample custom extension (e.g. iMessage App) payload sent through the passthrough API:
{
"role": "appMaker",
"type": "text",
"text": "Hello there",
"override": {
"apple": {
"payload": {
"attachments": [
{
"decryption-key": "00260450bb05cd4597a8ae706199f685c0f6fafee4b6c3e1375771c472f4149e29",
"file-size": "10159",
"mime-type": "image/png",
"mmcs-owner": "M39303332653438322d396338342d313165372d613330332d633735336231626666366661.C01USN00",
"mmcs-signature-base64": "AXG58GIo7xWZz7gRXZH2liWuzVah",
"mmcs-url": "https://p97-content.icloud.com",
"name": "icon.png"
}
],
"interactiveData": {
"URL": "?options=tacos,burritos",
"appId": 34554,
"appName": "Your App Name",
"bid": "com.apple.messages.MSMessageExtensionBalloonPlugin:ABCD5678:com.yourDomain.MessagesExtension",
"receivedMessage": {
"imageSubtitle": "Image Subtitle",
"imageTitle": "Image Title",
"secondarySubtitle": "Trailing Caption",
"subtitle": "Subcaption",
"tertiarySubtitle": "Trailing Subcaption",
"title": "Caption"
},
"useLiveLayout": false
},
"type": "interactive"
}
}
}
}
Apple Pay payment requests
Prerequisites for sending ApplePay payment requests include:
-
Apple Pay Merchant ID including:
- signed certificate (
developer.apple.com) - a verified Merchant Domain
- signed certificate (
- Apple Pay Merchant ID configured on the Business Chat account (
register.apple.com) -
Valid
MerchantSessionobject, obtained from Apple’s API- More details on MerchantSessions are available here
Sent using passthrough API, according to the Apple specification here
Responses are sent to the function-specific URL(s) specified in the request (in the interactiveData.data.payment.endpoints object)
Receiving Apple messages
Passthrough webhooks
To receive passthrough messages, subscribe to one of the passthrough webhook triggers through the Sunshine Conversations API. Note that these triggers must be explicitly subscribed for via the Sunshine Conversations API; they are not included in the * trigger.
| Trigger | Usage |
|---|---|
passthrough:apple:extension | Triggered when a custom extension message is received |
passthrough:apple:interactive | Triggered when a list picker, time picker, or other
interactiveDataRef
is received |
Example payload
The passthrough webhook payload includes the associated app, appUser, source, and raw payload received from Apple.
Here is an example passthrough payload for a list picker selection:
{
"app": { "_id": "59a8866f19ac1e893d8f39fe" },
"appUser": { "_id": "12130c355cf163c2dca397a9" },
"payload": {
"apple": {
"destinationId": "9032e482-9c84-11e7-a303-c753b1bff6fa",
"id": "45e36836-fa85-41a1-8c25-359e6c941d40",
"interactiveData": {
"bid": "com.apple.messages.MSMessageExtensionBalloonPlugin:0000000000:com.apple.icloud.apps.messages.business.extension",
"data": {
"listPicker": {
"multipleSelection": true,
"sections": [
{
"items": [
{
"identifier": "taco-appetizer",
"order": 0,
"style": "default",
"subtitle": "Great tacos",
"title": "Tacos"
},
{
"identifier": "taco-meal",
"order": 0,
"style": "default",
"subtitle": "Great tacos",
"title": "Tacos"
}
],
"order": 0,
"title": "You Selected"
},
{
"items": [
{
"identifier": "burrito-appetizer",
"order": 1,
"style": "default",
"subtitle": "Good burritos",
"title": "Burritos"
},
{
"identifier": "burrito-meal",
"order": 3,
"style": "default",
"subtitle": "Good burritos",
"title": "Burritos"
}
],
"order": 1,
"title": "Others"
}
]
},
"mspVersion": "1.0",
"requestIdentifier": "food-picker-1"
}
},
"sourceId": "urn:mbid:AQAAY5fm8C1h9GM7PJdHm1px6YYbfTH7R5Psfj0Lhh9dYbswZ+zfZekvmh6j1zuXMs7bovQJZ4d1Mw3TssgRy7mu1dXyTAY2uFrMhLt2HQILH5E6Jyq7VhpncbbIm58Ow4J6PbwgyaShPuccYT67n2TzF98KNOs=",
"type": "interactive",
"v": 1
}
},
"source": { "type": "apple" },
"trigger": "passthrough"
}
Closed conversations
Users can opt out from receiving further messages. When a customer deletes a conversation in Messages, a dialog appears that asks if they want to stop receiving messages from the business. If the customer chooses to stop receiving messages, Business Chat considers the conversation closed and sends a message of type close to the Sunshine Conversations. You can read more about this in Apple’s Developer Docs.
Upon receiving a close message, Sunshine Conversations will set client.status: blocked on the client with platform: "apple" of the corresponding appUser.
A client:block event will also be POSTed to subscribed webhooks.
Large Apple Business Chat message payloads
The existing Sunshine Conversations /messages and /templates APIs will not accept payloads larger than 100kb.
In order to remain compatible with Apple’s large payloads, Sunshine Conversations offers separate APIs designed specifically for handling large Apple Business Chat override payloads. The existing Sunshine Conversations /messages and /templates API accept the override parameter inside JSON payloads smaller than 100kb while a separate set of APIs will be offered that are designed to accept much larger payloads, up to 10mb.
| Standard Sunshine Conversations API (v1) | Large Apple paylaods equivalent |
|---|---|
POST
/v1/apps/:appId/appusers/:userId/messages | POST
/v1/apps/:appId/appusers/:userId/messages/large |
POST
/v1/apps/:appId/templates | POST
/v1/apps/:appId/templates/large |
PUT
/v1/apps/:appId/templates/:templateId | PUT
/v1/apps/:appId/templates/:templateId/large |
The large payload APIs may only be used for apps that have a valid ABC integration configured.
We strongly recommend using templates for sending large Business Chat messages whenever possible as constantly transferring the same large payload when sending the same content to multiple users generates unnecessary network traffic, which may cause message delivery latency.
Key differences
The large payload APIs behave the same as their conventional equivalents, except for two key differences:
override.apple.payload(ormessage.override.apple.overridefor templates) is required in the request body- Processing of the API calls are deferred to a queue (see section below for success confirmation and error handling)
Introducing requestId and webhooks for large payloads
Large message and template processing is deferred to a processing queue and therefore large payload APIs return 202 Accepted along with a requestId. For example:
{"requestId":"dkgSujU2R62HF3W9PnRIGy8K"}
This requestId can be used to track the success or failure of the request (message delivery or template creation/update) via two new webhook triggers: request:success and request:failure. The request body of request:success webhooks have a response key, whose value matches the structure returned from the associated standard API. request:failure webhooks have an “error” key mapping to an object containing error details. Possible error codes can be found here.
Example for POST /v1/apps/:appId/appusers/:userId/messages/large:
request:success example:
{
"trigger": "request:success",
"app": { "_id": "564f56151d195e2100c49f13" },
"appUser": { "_id": "4f75e8d7c26953e0df65bb40" },
"requestId": "dkgSujU2R62HF3W9PnRIGy8K",
"timestamp": 1534173863.84,
"response": {
"message": {
"_id": "5b71beb728ef8677a427c769",
...
},
"conversation": {
"_id": "1f706345a613e803962dfe54",
...
}
}
}
request:failure example:
{
"trigger": "request:failure",
"app": { "_id": "564f56151d195e2100c49f13" },
"appUser": { "_id": "4f75e8d7c26953e0df65bb40" },
"requestId": "dkgSujU2R62HF3W9PnRIGy8K",
"error": {
"code": "bad_request",
"message": "Invalid JSON"
},
"timestamp": 1534173863.84
}
Example of a large message request
SUNSHINE_CONV_ROOT='https://api.smooch.io'
APP_ID='your_app_id'
APP_USER_ID='app_user_id'
MESSAGE=$(cat <<-END
{
"type": "text",
"text": "Hello non-apple channel",
"role": "appMaker",
"override": {
"apple": {
"payload": {
"type": "interactive",
"interactiveData": {
"bid": "com.apple.messages.MSMessageExtensionBalloonPlugin:0000000000:com.apple.icloud.apps.messages.business.extension",
"data": {
"version": "1.0",
"requestIdentifier": "",
"images": [
{
"data": "base64encoded-image-file",
"identifier": "1"
},
{
"data": "base64encoded-image-file",
"identifier": "2"
},
{
"data": "base64encoded-image-file",
"identifier": "3"
}
],
"listPicker": {
"sections": [
{
"title": "Appetizers",
"order": 0,
"items": [
{
"title": "Tacos",
"order": 0,
"identifier": "taco-appetizer",
"imageIdentifier": "2"
},
{
"title": "Burritos",
"order": 1,
"identifier": "burrito-appetizer",
"imageIdentifier": "3"
}
]
},
{
"title": "Meals",
"order": 1,
"items": [
{
"title": "Tacos",
"order": 0,
"identifier": "taco-meal",
"imageIdentifier": "2"
},
{
"title": "Burritos",
"order": 1,
"identifier": "burrito-meal",
"imageIdentifier": "3"
}
]
}
]
}
},
"receivedMessage": {
"style": "small",
"title": "Food Picker",
"subtitle": "Let\"s eat!",
"imageIdentifier": "1"
},
"replyMessage": {
"style": "small",
"title": "Selected food",
"subtitle": "Nutrition"
}
}
}
}
}
}
END
)
curl $SUNSHINE_CONV_ROOT/v1/apps/$APP_ID/appusers/$APP_USER_ID/messages/large \
-X POST \
-H 'content-type: application/json' \
-H 'authorization: Bearer your-account-jwt' \
-d "$MESSAGE"
curl $SUNSHINE_CONV_ROOT/v1/apps/$APP_ID/templates/large \
-X POST \
-H 'content-type: application/json' \
-H 'authorization: Bearer your-account-jwt' \
-d '{
"name": "test-template-1234",
"message":'"$MESSAGE"'
}'
TEMPLATE_ID='your_template_id'
curl $SUNSHINE_CONV_ROOT/v1/apps/$APP_ID/templates/$TEMPLATE_ID/large \
-X PUT \
-H 'content-type: application/json' \
-H 'authorization: Bearer your-account-jwt' \
-d '{
"name": "new-template-name",
"message":'"$MESSAGE"'
}'
Large messages considerations
Just like the traditional /messages API, /messages/large can be used to send messages to users on channels other than Apple Business Chat. If you wish to target a user’s Apple client specifically you can do so via channel targeting.
Large templates considerations
Sending a large template is done using the standard /messages API, as described here.
It’s possible to convert a standard template to a large one by calling the PUT /templates/:templateId/large endpoint. Converting a large template to a standard one is also possible by calling the PUT /templates/:templateId endpoint and providing the message in the request body.
Large templates are deleted the same way as standard templates, by calling the DELETE /templates/:templateId endpoint.
Fetching large templates can be achieved by using the same APIs as for standard templates (GET /templates and GET /templates/:templateId). An isLarge property set to true will be included only for large templates (it won’t be present for standard templates.) Note that when retrieving a large template, the response will not include the Apple override section.