CloudKit is Apple's new cloud API that provides backend services for apps. It allows syncing of data across devices using iCloud. Some key features include user discovery through contacts, push notifications through subscriptions, and location-based queries. While CloudKit is ready for use in iOS and Mac apps, it currently only supports Apple platforms and some server functionality is unavailable. The cost model provides generous free storage and transfer quotas for individual users that scale with the number of users.

1. CloudKit Intro
NYC iOS Meetup, 9/3/14

2. About me
Arun Nagarajan (@entaq)
Currently
Founding Engineer, funded stealth startup in NYC
We are hiring! Email me at arun@isapp.com
Previously
2 yrs at Google - Tech Lead, Developer Platform
9 yrs at Verivo Software (Boston) - VP of Architecture

3. What is it?
● New Cloud API that provides backend to app
● Other “iCloud” options
○ iCloud Core Data
○ iCloud Documents/Drive
○ iCloud Key Value Store
● Transport technology
○ And not a local persistence layer
● 400 million iCloud accounts
● Apple used it to build iCloud Drive & Photos

4. Key entities
● Containers
● Databases
● Records
● Record Zones
● Record Identifiers
● References
● Assets

5. Enabling CloudKit

6. Some favorite features

7. User Discovery
● User Record ID - unique per app/per user
● Email address if user opts in
● Scan address book for other contacts
○ You never get address book
● One new permission dialog

8. Salient points
● Error handling is key
● NSOperation based API
○ And a convenience API
● Subscriptions/Push notification is solid
● Querying based on NSPredicates
○ Location based queries
● Dashboard
○ https://icloud.developer.apple.com/dashboard/

9. Is it ready?
● For now, Apple only (iOS and Mac)
● Some server unavailable errors
● No way to run server side code
● Plenty of other options!
○ Hard to port over for the most part

10. Some troubles

11. Cost model
● Public database quota for developer
● Private database quota for users

12. Costs
Storage - 5gb for assets, 50mb for DB
Transfer - 25mb/day assets, 250kb/day DB
For every user, you get
Storage - 100mb for assets, 1mb for DB
Transfer - 500kb/day assets, 5kb/day DB

13. Sample costs
10k users
Storage - 1tb for assets, 10gb for DB
Transfer - 5gb/day assets, 50mb/day for DB
100k users
Storage - 10tb for assets, 100gb for DB
Transfer - 50gb/day assets, 500mb/day for DB

14. Thanks
Questions?
Arun Nagarajan
arun@isapp.com