API:Changing wiki content

Changing wiki content through the API is enabled by default as of MediaWiki 1.14; it can be disabled by setting $wgEnableWriteAPI = false; in LocalSettings.php. In MediaWiki 1.13 and earlier, you have to explicitly enable the write API with $wgEnableWriteAPI = true;

Please see the appropriate subsection for detailed information for each module.
 * Edit about the action to create new articles or modify existing ones.
 * Move about the action to rename or move articles.
 * Rollback about the action to rollback the last series of contributions to a page.
 * Delete about the action to delete existing articles.
 * Undelete about the action to view and restore deleted revisions.
 * Protect about the action to change the protection levels for a page.
 * Block about the actions to block and unblock a user.
 * Watch about the action to watch and unwatch pages.
 * Email about the action to send email to other users.
 * Patrol about the action to patrol changes.
 * Import about the action to import pages from other wikis.
 * User group membership about the action to add and remove users to and from groups.
 * Upload about the action to upload files.
 * Tokens about the action to get session-based tokens required for some actions.

Possible errors
Some wikis restrict the use of these modules to certain groups of users, or disallow it altogether. All aforementioned modules can return the following errors: