The document discusses the growth of APIs and argues that APIs need to adopt HATEOAS (Hypermedia as the Engine of Application State) principles in order to become browsable and drive mass adoption. It outlines how relationships between resources are important for enabling browsability, versionless APIs, and network effects. The author describes their company Elastic Path's past failed API efforts and its Cortex API engine, which was built to help implement HATEOAS principles and address issues they encountered with other frameworks.

1. HATEOAS APIS
Matt Bishop, Product Architect at Elastic Path
@MattBishopL3

2. Growth of APIs, How Exciting!
www.elasticpath.com @MattBishopL3

3.  Actually, it’s more like 14,000
 1 minute per API = 6 weeks end-to-end
www.elasticpath.com @MattBishopL3

4. REST beats SOAP, How
Exciting!
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5. Growth of Internet Hostnames
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6. What happened in the 90s?
 1989 HTML invented (thanks Tim!)
 1992 First browsers built
 1994 Netscape launched
 1995 Internet Explorer in Win95, IIS bundled in
NT, Apache, PHP released
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7. Internet Host Names In A Line
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8. Make a Website, 1995-style
 Web sites were coded in:
• Java
• C / C++
• Perl
• ColdFusion
• Python
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9. Templates Blew the Doors off the
Internet
 Late 90s Microsoft ASP, Apache JSP,
DreamWeaver, Velocity, etc.
 Templates opened internet development to the
common man
 Templates made data BROWSABLE
www.elasticpath.com @MattBishopL3

10. Templates made data browsable
 Made linking easy
 <asp:HyperLink …
 <a href=“<%= getLink
(somedata) %>
 Easy linking means
easy browsability
 Drives the Network
Effect
www.elasticpath.com @MattBishopL3

11. APIs are stuck in the 80s
 …1987, to be exact (28,174 hosts)
 APIs must be browsable before they can be
adopted by 100m organizations
 100m organizations == your sister’s dress
store, my mom’s knitting club
www.elasticpath.com @MattBishopL3

12. Comfortably Numb
We can stay stuck here if we
don’t link our resources
together
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13. Links are about Relationships
 Relationships are hard
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16. Relationships are not hard after
all
• Relationships are a fundamental part of being
an animal
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17. Relationships make Versionless
APIs possible
 Relationships are very stable
 The resources themselves move, but their
relationships do not
 GET /profiles/id
• “addresses”: “/profiles/id/addresses”
? Hmm maybe addresses should be their own
resource ?
GET /profiles/id
• “addresses”: “/addresses”
www.elasticpath.com @MattBishopL3

18. Relationships make APIs
browsable
 Browsable APIs == Browsable data == mass
adoption
 First step is to make it easy to link
www.elasticpath.com @MattBishopL3

19. Cortex API Engine
 Elastic Path’s API endeavors have failed four
times
 2010 drank the HATEOAS Kool-Aid, reset our API
effort
 Found no frameworks to help past URI-to-method
mapping and ser/deser
 We built an engine using some existing
technology (Jax-RS, Spring, Shiro) and our own
work
 Cortex is an API engine that happens to run
www.elasticpath.com @MattBishopL3

20. Cortex Design Philosophy
• Small, simple resources written by BAs
• Small, simple state changes via controls
• Form
• Selector
• “Secret Admirer” rule
• All Operations are identified
• REST is the Gestalt, HTTP is a transport
www.elasticpath.com @MattBishopL3