UPDATE (30/10): Official documentation has been published -> https://docs.microsoft.com/en-us/dynamics365/customer-engagement/developer/clientapi/reference/xrm-webapi. Andrii got it right. IMHO this feels a little clunky and incomplete, as you need to now the message parameters along with the types. Luckily it appears Jason is already working on this issue -> https://github.com/jlattimer/CRMRESTBuilder/issues/30 and once this this will make life easy again.

UPDATE (23/10): Part 2 (http://butenko.pro/2017/10/18/microsoft-dynamics-365-v9-0-usage-of-new-oob-webapi-functions-part-2/) & Part 3 (http://butenko.pro/2017/10/18/microsoft-dynamics-365-v9-0-usage-of-new-oob-webapi-functions-part-3/) have been published. I am not sure if this is how MS intends this to be used. I’ll will wait for official MS documentation for confirmation regarding this.

UPDATE (18/10): It appears Andrii got to this topic first -> http://butenko.pro/2017/10/05/microsoft-dynamics-365-v9-0-usage-of-new-oob-webapi-functions-part-1/. I should have probably subscribed to his RSS feed – could have saved some time for me. Anyway there is also a Part 2 that he has not posted yet, so I am looking forward to see what I missed.

Dynamics 365 Customer Engagement v9 has added CRUD functionality to query the WebAPI endpoint using Client API.

Based on my initial analysis, this seems to be a work in progress and more functions will be added over time. This is some sample code how you can do the basic CRUD using this new feature. This is not an exhaustive documentation, but considering that there is nothing about this in the official documentation, it is a starting point.

Create : Method signature is ƒ (entityType, data)

Sample code to create 3 contact records

[...new Array(3).keys()].forEach(x => Xrm.WebApi.createRecord('contact', {
    firstname: 'Test',
    lastname: `Contact${x}`
}).then(c => console.log(`${x}: Contact with id ${c.id} created`))
  .fail(e => console.log(e.message)))

Retrieve: Method signature is ƒ (entityName, entityId, options)

Sample code to retrieve contact record based on the primary key

Xrm.WebApi.retrieveRecord('contact', 'cadf8ac6-17b1-e711-a842-000d3ad11148', '$select=telephone1')
  .then(x => console.log(`Telephone: ${x.telephone1}`))
  .fail(e => console.log(e.message))

RetrieveMultiple: Method signature is f(entityType, options, maxPageSize)

Sample code to retrieve 10 contact records without any conditions.

Xrm.WebApi.retrieveMultipleRecords('contact', '$select=fullname,telephone1', 10)
  .then(x => x.entities.forEach(c => console.log(`Contact id: ${c.contactid}, fullname: ${c.fullname}, telephone1: ${c.telephone1}`)))
  .fail(e => console.log(e.message))

Update: Method signature is ƒ (entityName, entityId, data)

Sample code to update field on contact record

Xrm.WebApi.updateRecord('contact', 'cadf8ac6-17b1-e711-a842-000d3ad11148', {
    telephone1: '12345'
}).then(x => console.log(`Contact with id ${x.id} updated`))
  .fail(x => console.log(x.message))<span 				data-mce-type="bookmark" 				id="mce_SELREST_start" 				data-mce-style="overflow:hidden;line-height:0" 				style="overflow:hidden;line-height:0" 			></span>

Delete: Method signature is ƒ (entityName, entityId)

Xrm.WebApi.deleteRecord('contact', '88E682D8-18B1-E711-A842-000D3AD11148')
  .then(c => console.log('Contact deleted'))
  .fail(x => console.log(x.message))

What is not yet done/appears to be in progress

1. Xrm.WebApi.offline not yet implemented
2. Ability to construct custom OData requests to pass into Xrm.WebApi.execute (Refer Andrii’s post)
3. Batching multiple requests (Refer Andrii’s post)

You can use this on your client side code on v9. It is quite basic at the moment, but you don’t need to include any external libraries. But in more advanced scenarios, you can always use Xrm WebAPI Client till these features are made available in the Client API.

Reference: https://docs.microsoft.com/en-au/dynamics365/get-started/whats-new/customer-engagement/new-in-july-2017-update-for-developers#new-client-apis