MediaWiki:Api-help-methods

Action API requests may use GET and POST methods. Prefer using the GET method, which allows requests to be routed to faster replica servers and responses to be cached, unless the length of the URL with parameters would exceed its length limit (commonly 8000 bytes), or a module only accepts POST requests.

Parameters for POST requests may be sent in the query part of the request URL (like in GET requests) and in the POST request body, and mixing both ways in one request is allowed. Certain parameters such as passwords must be sent in the request body. If the same parameter is sent as part of the URL and also in the request body, it must have the same value in both places.