1. VuFind APIs - A practical approach
Ere Maijala
VuFind Summit 2016

2. ”APIs are great, can we add them?”
”Like, for what?”
Types of APIs
Backend
Front-end
Interactive
Generic
What’s common
A request comes in
The request is processed
There’s a predefined structured outcome
”Like, when you enter a URL in the browser, you get some HTML?”
”No, see, structured.”

3. Shibboleth Single Logout
”Users’ sessions don’t end properly in the Identity Provider, do something!”
Backend API
Between Shibboleth Service Provider and VuFind
When Shibboleth logout is processed, an API in VuFind is called to signal that the session must be terminated
On login, the Shibboleth session id is stored in VuFind database mapped to VuFind session id
On logout, this mapping is used to terminate the VuFind session
Shibboleth chains the logout requests so that they propagate to all services
Already available in vufind-org/master

4. External Authentication - EZproxy
”So we moved from MetaLib to Finna [VuFind] and you still expect us to send users to MetaLib for EZproxy authorization?”
Interactive API
EZproxy redirects user to VuFind upon login
VuFind prompts the user to log in (if not already)
If the user is authorized, VuFind redirects back to EZproxy with a ticket
Ticket is a hash from a shared secret and other details
If authorization fails, user is informed in VuFind
Already available in vufind-org/master

5. Search API
”We are creating Cool Service X and we would like to access your search index”
A generic API
Work in progress
Based on a practical approach (read: do something really quickly and try to make it nice later)
Oops, a front-end service now becomes a backend others depend on

6. Search API Goals Simple
Easy to use with modern tools (JSON, CORS, Swagger specification)
Parameters as similar as possible to the search functionality in the VuFind UI
Extensible with local fields etc.
Easy to extend with new functionality
Take advantage of record drivers
Support API versioning from get-go
Use permissions

7. Search API Development Steps
First proof of concept: extend search results view=rss with view=json
Test it out
Move it to a separate controller
Create documentation
Publish the API with VuFind 2 (Feb 2016)
Gather feedback and improve on it
Most feedback has been about the content and index features, not the API implementation
Contribute upstream:
Separate module for the API functionality
Other awesome improvements in architecture thanks to Demian’s comments

8. Future API Development Possibilities
Low-hanging fruits
Read access to public lists
Read access to record comments
Other indexes like authorities
Advanced search, maybe
In the middle
Token authorization with e.g. JWT (JSON Web Tokens)
Holdings and new items from the ILS
Possibly other read-only ILS APIs
Rate limits
Usage limits
Content-type negotiation (if something else than JSON is needed)
High above
Read-write APIs

9. Search API Demo Our local production version at https://api.finna.fi/
Docs:
Upstream version at [my computer]:

10. Ere Maijala ere.maijala@helsinki.fi
Not bad, huh?
Ere Maijala