1. The World Of Connected APIs
David Robinson
Director of Engineering
Information Management – China

2. Linked Information Systems
“When describing a complex system, many people resort to diagrams with circles and arrows. […] The system we need is like a diagram of circles and arrows, where circles and arrows can stand for anything. […] The system must allow any sort of information to be entered. Another person must be able to find the information, sometimes without knowing what he is looking for.” – Tim Berners-Lee 1989

3. Evolution of Linked Systems
World Wide Web
REST APIs
Graph APIs
Connected APIs

4. Early World Wide Web A set of connected links (hypermedia)
Audience: Designed for humans
Components: HTML, Image, CSS
References: Links
Interactive browsers, portals

5. REST APIs A set of connected resources (REST)
Audience: Designed for single-function apps
Components: Resources, Entities
References: “Links”
A loss of a fundamental concept: No external linkage!

6. Graph APIs
A subset of REST APIs with properly connected resources (graphs)
Audience: Designed for multi-function apps
Components: Resources, Entities
References: Links

7. Connected APIs
Large companies (Alibaba, Microsoft) often offer many APIs
Burden is on the developer to bridge the gaps
Connected APIs integrate disjoint graphs into a single connected interface
Developers efficiency

8. Evolution of Connected APIs

9. Single Hypermedia API
Few resources
Useful linkage

10. Adding Hypermedia APIs
More resources
Still useful linkage
Conceptually similar “user”

11. Many hypermedia APIs
10-100s APIs
Self-contained
Properly modeled

12. Too many hypermedia APIs
Duplication
Manually bridging APIs

13. Connected APIs
No duplication
Cross API hypermedia links
Discoverability

14. Connected API Enabled Queries
Find all of the people on my team who have edited >100 documents Show me what day of the week my manager schedules most meetings on Get the authors of the documents that have been attached to >10 s

15. How is Microsoft Connecting APIs?
Short-term: combination of automation and manual effort
Long-term: fully automated effort
Automation is enabled by standardization + API guidelines
OData provides a standardized base for REST APIs

16. Connected APIs
The past and present have shown us the importance of connectedness
APIs need to be connected to ease the burden on developers
To automate connectedness, adopt a standard like OData

17. Upcoming Talks O365 APIs OData Exchange Protocols
Mail, Calendar, & Contacts