API:Tutorial

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An introduction to the API by Roan Kattouw at the San Francisco Hackathon January 2012. This tutorial guide goes along with the video.

This page contains the notes used to present Roan Kattouw's 2012 workshop on the MediaWiki web API and is not a complete tutorial on the MediaWiki web API by any means. It provides a quick introduction to the API, useful recipes for common GET requests, and a list of available resources with more information.


Tools clipart.png This page is part of the MediaWiki API documentation.
MediaWiki API

Quick overview:

v · d · e

Tutorial for MediaWiki's RESTful web service API[edit | edit source]

Why should you use the web API? Bots, AJAX, Gadgets, other things.

Roan says: generally any Ajax feature is going to use the api.php entry point. But right now the easiest thing to do is to write a bot or to use the API clients.

Definitions[edit | edit source]

  • REST API for MediaWiki
    • exposes things MediaWiki has in the database or otherwise understands
    • does not include semantic stuff like "definition of a word in Wiktionary" or even "lead paragraph of an article"
    • usage: send HTTP requests (GET or POST) to the api.php URL, receive XML or JSON or other formats. You'll usually want JSON or XML.

There are other things that also get casually called the MediaWiki API, like the internal interfaces that extensions and special pages can hook into. We're not talking about that right now, just the web API.

(possibly talk about how it works from the back end, if people ask)...

How to use it[edit | edit source]

  • Entry point: http://en.wikipedia.org/w/api.php (see API:Main page#The endpoint)
    • or any other wiki
      • Talk about versioning and how non-WMF wikis might have different version of MediaWiki and thus the API
    • https works too!
  • Parameters are passed in query string. Not passing any will give you the help page with the autogenerated documentation.

Follow along by using w:en:Special:ApiSandbox -- query is what you will usually want.

  • Example query: ?action=query&titles=San_Francisco&prop=images&imlimit=20&format=jsonfm
    • action=query is used for most read actions, separate action= modules exist for write actions
    • titles= takes one or more titles for the query to operate on
    • prop=images lists the images on a page; lots of other stuff in prop=, list=, meta=
    • limit= sets the max # of results. Default is 10, 'max' works
    • popular values for format= : xml, json, xmlfm (default), jsonfm
    • If you want to find sections from the table of contents, use section= using the index property, and you can call 0 for the wikitext that comes before the first section header.
  • State-changing actions (e.g. editing)

If you want to make a lot of API calls, and perhaps run very busy and active bots et al., please talk to the admins of that wiki ahead of time so they do not block you. Also run your requests in serial, not parallel. resource for contacting them to go here. TODO

  • There are limits in the software on how many edits per second you can make.
  • Example nouns to look up:
Kanichar
Kolar_Gold_Fields
Cooperative_principle
MS_Riverdance


Magic recipes[edit | edit source]

Nonobvious and very useful (these may be outdated - 12/2014)

  • Things you'll definitely need:
    • prop=info for basic page info
    • prop=revisions for page history
    • prop=revisions&rvprop=content for page wikitext
    • action=parse for page HTML
  • Doing crazy stuff
    • multiple titles with titles=Foo|Bar|Baz (This will make multiple calls count as one for the purpose of rate limiting)
      • This works for pages but not revisions. Read the documentation via the Sandbox or via api.php autodocs.
    • multiple modules with &prop=images|templates&list=allpages|blocks
    • generators (kind of like UNIX pipes) with &titles=Foo&generator=links&prop=revisions

Resources[edit | edit source]

  • Getting help
    • Autogenerated documentation: api.php with no parameters such as https://en.wikipedia.org/w/api.php
    • Documentation on mediawiki.org: API:Main page (details about specific modules/parameters often outdated, autogenerated docs are authoritative)
    • The API Sandbox -- example w:en:Special:ApiSandbox
    • mail:mediawiki-api -- mediawiki-api@lists.wikimedia.org
    • mediawiki-api-announce@lists.wikimedia.org - PLEASE subscribe because we tell you about breaking changes, which happen a few times every year. mail:mediawiki-api-announce
    • #mediawiki on irc.freenode.net
    • me! (Roan Kattouw)

You may actually want[edit | edit source]