Short deck describing the fundamental difference between Level 3 REST and the other levels.

1. Level 3 REST
Matt Bishop
Sr. Product Architect
Elastic Path Software, Inc.

2. Richardson Maturity Model
Level 0 : RPC
POST /apptService <xml get doctors appt list>
?? How do I book an appointment? Check the docs
Level 1: Resources, but verbs in the body
POST /doctors/mjones <xml get appt list>
?? How do I book an appointment? Check the docs
Level 2: Resources and HTTP Verbs, but actions are unknown
GET /doctors/mjones/slots?date=…&status=open
?? How do I book an appointment? Check the docs
© Copyright 2012, Elastic Path Software Inc. All rights reserved.

3. Level 3 REST
Everything is expressed as links in the body
GET /doctors/mjones/slots?date=…&status=open
<openSlotList>
<slot id = "1234" doctor = "mjones" start = "1400" end = "1450">
<link rel = "/linkrels/slot/book” uri = "/slots/1234"/>
</slot>
</openSlotList>
?? How do I book an appointment? Follow the link
© Copyright 2012, Elastic Path Software Inc. All rights reserved.

4. Email before HTML
© Copyright 2012, Elastic Path Software Inc. All rights reserved.

5. Groups before HTML
© Copyright 2012, Elastic Path Software Inc. All rights reserved.

6. Level 2 REST is PINE and USENET
• Like the Internet before HTML
• Must read manpages (documentation) to
understand
• Fancy manpages, mind you:
• Swagger
• Apiary.io
• But still requires training and special knowledge
© Copyright 2012, Elastic Path Software Inc. All rights reserved.

7. Links make APIs Browsable
• Level 3 REST is not Level 2++
• Paradigm shift, a Kierkegaardian leap
• Difficult to build – no frameworks, specs, tools
BUT
• Browsable APIs are easy to discover and consume
• Docs become the ‘site map’
© Copyright 2012, Elastic Path Software Inc. All rights reserved.