API:Login

When using MediaWiki's web service API, you will probably need your application or client to log in. This involves submitting a login query, constructing a cookie, and confirming the login by resubmitting the login request with the confirmation token returned.

Whether to log in
Your client will need to log in to MediaWiki if:


 * it needs to obtain information or carry out an action that is restricted to users with certain rights
 * it is making large queries that would be inefficient without the higher per-request limits reserved for accounts with certain rights

On wikis that allow anonymous editing, it's possible to edit through the API without logging in, but it's highly recommended that you do log in. On private wikis, logging in is required to use any API functionality.

If your client is written in JavaScript, it'll usually act with the credentials of the user who's running it. In this case, you won't need to login using the web service API--you'll just need to ensure that the user has logged in through the web interface.

Application-specific user accounts
Rather than having your application log in as yourself, you may want to create a separate user account just for your application. This is especially important if your application:


 * is carrying out automated editing or some other bulk operation.
 * invokes large or performance-intensive queries.

With a separate account, the changes made by your application can be easily tracked, and special rights (usually a "bot" user group) can be applied to the application's account. Some wikis have a policy related to automated editing, and/or a procedure for dealing with "bot" user group requests.

Login gets several tokens that are needed by the server to recognize the logged-in user. In every call to api.php, the cookie set by this request must be passed. The cookies last for around a month and you should check that you need to log in based on detecting that you're not logged in (rather than logging once per session, for example). You can check this on any request using the  generic parameter.

How to log in
Logging in through the API requires submitting a login query and constructing a cookie (many frameworks will construct the cookie automatically). In MediaWiki 1.15.3+, you must confirm the login by resubmitting the login request with the token returned.

Structure of login request
The body of the POST can be empty. This request will also return a session cookie in the HTTP header that you have to return for the second request if your framework does not do this automatically. The sessionid parameter was added in MediaWiki 1.17 and later.

You might need to add the query parameter, containing your domain name for authentication, if you're using an authentication plug-in like Extension:LDAP Authentication.

Confirm token
If the response to the above query was  instead of , you can skip this step. (This extra step was added in MediaWiki 1.15.3.) In MediaWiki 1.15.4, first phase of login in ApiLogin.php is broken, so login/sessionid parameter is not returned, thus token confirmation is impossible. Apply ApiLogin.php file from MediaWiki 1.15.5 to your installation as a quick workaround while you plan your upgrade to 1.15.5. ApiLogin.php from MediaWiki 1.16+ is incompatible with MediaWiki 1.15.3+.

Handle cookies
A successful  request will set cookies needed to be considered logged in. Many frameworks will handle these cookies automatically (such as the cookiejar in cURL). If so, by all means take advantage of this. If not, the most reliable method is to parse them from the HTTP response's Set-Cookie headers.

If this is not possible either, it is possible to construct the appropriate cookies from the various values returned by the  call, but this is not recommended as the necessary cookies may be changed without warning (e.g. something as simple as changing $wgSessionName would require changes to your manual cookie creation code).

When CentralAuth is enabled, as on Wikimedia wikis, the example above will not only log you in to a single domain, but also provide you with three centralauth cookies in the Set-Cookie response headers. To use these, duplicate those cookies (i.e. cookies whose names are prefixed with "centralauth_") and set the domain field of the new cookies to the new domain you'd like to log in at. Once this is done, any GET/POST request to this new domain will (assuming that the user has a SUL/global account) be answered with a reply containing Set-Cookie headers/Cookies specific to that domain.

Errors
Errors are returned in the result field. Possible values include:

Throttling
For security reasons, this module is throttled. By default, you get to login 5 times in 300 seconds, but this may vary from one wiki to another. When you exceed this limit, your login will fail (even if it's otherwise correct) with  and the number of seconds you need to wait in the   field.

Examples

 * Example login code in PHP (requires Snoopy)
 * Example login code in PHP (using cURL) - no Snoopy required
 * Example login code in JS (using JQuery)
 * Example login code in Python