From CKAN

Use the CKAN API to get at the data catalogue programmatically. In your own web page or program you can:

• Get any bit of CKAN data
• Edit CKAN data
• Create a whole new web front-end for CKAN (if you want!)

Examples of use:

• The Linked Open Data cloud is drawn with a script that gets the dataset info from CKAN: http://thedatahub.org/group/lod
• Open Spending scripts scan the CKAN API at http://catalogue.data.gov.uk/ for spending datasets and present them here: http://data.gov.uk/openspending
• data.gov.uk has PHP to get datasets from the CKAN API at http://catalogue.data.gov.uk/ API to get datasets and load them into a CMS
• data.gov.uk has a python script that reads the datasets from the Office of National Statistics and loads them into CKAN at data.gov.uk using the API.

The official reference documentation for the CKAN API is in the Administrator Manual: http://docs.ckan.org/en/latest/api.html

This page provides additional information and an overview.

Contents 1 Introduction to the CKAN API 2 API Reference Documentation 3 Tutorial 4 API Client Libraries 4.1 Javascript Client 4.2 Python client 4.3 Command-line client 4.4 PHP client 4.5 Perl client example 4.6 Other Code related to CKAN 4.6.1 Drupal module 5 Other Examples of Using the API

Introduction to the CKAN API

To use a the CKAN API, your application will make an HTTP request and parse the response. By default, the response format is JSON. Most of the API is RESTful and your methods will be the standard HTTP methods like GET, PUT, POST and DELETE.

CKAN's APIs provide access to all of the objects in the CKAN Domain Model. The standard access url is:

/api/rest/{object-name}/{object-id}

There are API endpoints for:

• Domain Model/Package
• Domain Model/Group
• Domain Model/Revision

API Reference Documentation

See the CKAN Administration Guide for the CKAN API Reference: http://docs.ckan.org/en/latest/api.html

Tutorial

Using_the_API

API Client Libraries

There exist clients for the CKAN API in several languages

Javascript Client

The CKAN API can just be used directly from jquery. However, for more sophisticated uses -- as well as a source of code examples -- you may wish to check out the CKAN Javascript client library:

• Code: http://github.com/okfn/ckanjs
• Docs: http://github.com/okfn/ckanjs

Python client

The Python client is officially maintained by the CKAN core developers.

• Code: http://pypi.python.org/pypi/ckanclient
• Docs: http://ckan.org/documentation.
• Author: CKAN team

Command-line client

Datapkg allows you to download the data in CKAN packages on the command-line, in the style of software package managers (e.g. apt-get, cpan, pypi).

• Docs: http://packages.python.org/datapkg/
• Source: http://bitbucket.org/okfn/datapkg
• Author: CKAN team

PHP client

Ckan_client-PHP is an almost full and (I hope) easy-to-use interface to the CKAN APIs.

• Source: http://github.com/jeffreybarke/Ckan_client-PHP
• Author: Jeffrey Barke This example uses CKAN's search API and lists and reads Packages/Groups with the REST API.

Perl client example

This example accesses the CKAN REST API to get a list of the packages, count the uses of an 'extra' field and then plots it with the Google chart API. Luke broke the CKAN bits out into a CKAN specific client library - Net::CKAN.

Luke is open to improving this library and eventually releasing it to CPAN.

• Script Source: http://github.com/lukec/net-ckan/blob/master/bin/make-ckan-chart
• Library Source: http://github.com/lukec/net-ckan/blob/master/lib/Net/CKAN.pm
• Info: http://lists.okfn.org/pipermail/ckan-discuss/2010-February/000057.html
• Author: Luke Closs

Other Code related to CKAN

Drupal module

A Drupal module for integrating with CKAN.

Advanced module:

• Blog post
• ckanpackage.tar.gz (and available on drupal.org)
• Author: Data.gov.uk

Simple module:

• http://www.practicalweb.co.uk/blog/10/02/24/drupal-module-ckan-integration
• Author: Sean Burlington

Other Examples of Using the API

• http://www.practicalweb.co.uk/blog/10/02/23/accessing-ckan-data-php
• Author: http://practicalweb.co.uk/ Sean Burlington