API:Errors and warnings

This page is part of the MediaWiki API documentation.

MediaWiki API

Quick overview:

• Quick start guide
• FAQ
  • Etiquette and usage limits
• Tutorial
• Formats
• Error reporting
• Restricting usage
• Cross-site requests
• Authentication
  • Login
  • Logout
  • Account creation
• Queries
  • Meta information
  • Properties
  • Lists
• Search suggestions
• Parsing wikitext and expanding templates
• Purging pages' caches
• Parameter information
• Changing wiki content
  • Create and edit pages
  • Move pages
  • Rollback
  • Delete pages
  • Restore deleted revisions
  • (Un)protect pages
  • (Un)block users
  • (Un)watch pages
  • Send email
  • Patrol changes
  • Import pages
  • Change user group membership
  • Upload files
  • User options
• Watchlist feed
• Wikidata
• Extensions
• Using the API in MediaWiki and extensions
• Miscellaneous
• Implementation
• Client code

If something goes wrong in an API request, an error or a warning will be thrown. Warnings are thrown for non-fatal conditions such as invalid parameters, whereas errors are only thrown for fatal conditions.

Warnings

Warnings are output in the following format:

<?xml version="1.0" encoding="utf-8"?>
<api>
  <warnings>
    <query>Warning text
Another warning</query>
    <info>A warning from prop=info</info>
  </warnings>
</api>

As shown in the example, warnings are grouped by the name of the module that caused them. Multiple warnings from the same module are separated by a newline.

Disabled modules

Disabled action=query submodules will always throw the following warning:

• The ``modulename'' module has been disabled.

Parameter validation warnings

The following warnings can be thrown when validating parameters, and can therefore be thrown by all modules. paramname is replaced by the name of the parameter.

• Too many values supplied for parameter 'paramname': the limit is limit
• Unrecognized value for parameter 'paramname': value
• Unrecognized values for parameter 'paramname': value1, value2, value3

Errors

Error messages are output in the following format:

<error code="code" info="info" />

Where code is replaced with a short error code (which need not be unique to the error) and info with a more elaborate description of the error (which is unique). Also, the error code will be returned in the MediaWiki-API-Error HTTP header. For an example error response or to test your client's error handling, see http://en.wikipedia.org/w/api.php?action=blah

Note that when viewing errors in pretty-print formats, the API help will be returned inside the <error> element. To save bandwidth, this doesn't happen for non-pretty-print formats; if you specifically want the help text in a non-pretty-print format, use action=help.

Error messages in the documentation

Error messages are documented as follows:

• code: apparams
  • info: prlevel may not be used without prtype

Which corresponds to:

<error code="apparams" info="prlevel may not be used without prtype" />

Disabled modules

Disabled action= modules will always fail with the following error:

• code: moduledisabled
  • info: The ``modulename'' module has been disabled.

Parameter validation errors

The following errors can be thrown when validating parameters, and can therefore be thrown by all modules. paramname is replaced by the name of the parameter.

• code: multival_paramname
  • info: Only one of 'value1', 'value2', 'value3' is allowed for parameter 'paramname'
• code: unknown_paramname
  • info: Unrecognized value for parameter 'paramname': value
• code: paramname
  • info: paramname may not be set to less than min (set to value)
• code: paramname
  • info: paramname may not be set over max (set to value) for bots and sysops
• code: paramname
  • info: paramname may not be set over max (set to value) for users
• code: badtimestamp_paramname
  • info: Invalid value value for timestamp parameter paramname
• code: baduser_paramname
  • info: Invalid value value for user parameter paramname
• code: invalidparammix
  • info: The parameters param1, param2, param3 cannot be used together
• code: missingparam
  • info: One of the parameters param1, param2, param3 is required
• code: _badcontinue
  • info: Invalid continue param. You should pass the original value returned by the previous query

Standard error messages

Some generic error messages are shared among modules. If a module can throw these errors, that's explicitly mentioned in its Possible errors section.

• code: unknownerror
  • info: Unknown error
    • This usually means something crazy like a rare race condition occurred. If you get this error, retry your request until it succeeds or returns a more informative error message
• code: unknownerror
  • info: Unknown error errorcode
• code: unsupportednamespace
  • info: Pages in the Special namespace can't be edited
• code: protectednamespace-interface
  • info: You're not allowed to edit interface messages
• code: protectednamespace
  • info: You're not allowed to edit pages in the ``namespace'' namespace
• code: customcssjsprotected
  • info: You're not allowed to edit custom CSS and JavaScript pages
• code: cascadeprotected
  • info: The page you're trying to edit is protected because it's included in a cascade-protected page
• code: protectedpage
  • info: The ``right'' right is required to edit this page
• code: permissiondenied
  • info: Permission denied
• code: confirmemail
  • info: You must confirm your e-mail address before you can edit
• code: blocked
  • info: You have been blocked from editing
• code: autoblocked
  • info: Your IP address has been blocked automatically, because it was used by a blocked user
• code: ratelimited
  • info: You've exceeded your rate limit. Please wait some time and try again
• code: readonly
  • info: The wiki is currently in read-only mode
• code: badtoken
  • info: Invalid token
• code: missingtitle
  • info: The page you requested doesn't exist
• code: mustbeposted
  • info: Type of your HTTP request message must be POST
• code: hookaborted
  • info: The modification you tried to make was aborted by an extension hook
• code: nosuchpageid
  • info: There is no page with ID id
• code: nosuchrevid
  • info: There is no revision with ID id
• code: nosuchrcid
  • info: There is no change with rcid ``id''
• code: nosuchuser
  • info: The user you specified doesn't exist
• code: invalidtitle
  • info: Bad title ``title''
• code: invaliduser
  • info: Invalid username ``username''