The M-Files Web Service (MFWS) is a REST-like web service that is available from within M-Files Web Access. Note that this must be configured separately from the standard M-Files server, and may not be available on all installations. The following differences are important to note when compared with the COM API:

  • The MFWS can be used from any environment that can make HTTP requests, and is not limited to Windows operating systems.

  • The MFWS supports most “user” operations but cannot (natively) be used to undertake administrative operations.

  • Code interacting with the MFWS is not directly dependent on the M-Files sever version; as the sever and MFWS are updated, it is unlikely that your code will require further changes.


The M-Files Web Service (MFWS) is part of the M-Files Web Access. Once M-Files Web Access is correctly configured, the M-Files Web Service will be available to use. More information on setting up the M-Files Web and Mobile Access is available in our user guide. Once configured the REST API is available within the M-Files Web Access at /REST/. If your Web Access has been configured in a subdirectory then remember to prefix that on all links (e.g. if it’s in /MFiles/ then your REST API is available within /MFiles/REST/).

IIS compatibility

HTTP verbs

The official M-Files Web Service documentation defines endpoints that use different HTTP verbs in order to provide different functionality. As an example:

Depending upon the version of Windows, IIS, and M-Files being used, sometimes only the GET and POST HTTP verbs will correctly work. For maximum compatibility it is recommended that DELETE and PUT requests are routed via the _method querystring parameter, as shown below.

Original method Original endpoint Compatible method Compatible endpoint Change
GET /REST/resource GET /REST/resource None
POST /REST/resource POST /REST/resource None
PUT /REST/resource POST /REST/resource?_method=PUT Change to POST request and ensure that the _method parameter is set on the querystring, with a value of PUT (the original verb).
DELETE /REST/resource POST /REST/resource?_method=DELETE Change to POST request and ensure that the _method parameter is set on the querystring, with a value of DELETE (the original verb).

File extensions

Older versions of IIS do not correctly map “extensionless” handlers to the M-Files Web Service. To resolve this, include .aspx on the end of all endpoint addresses:

Original endpoint Compatible endpoint
/REST/resource /REST/resource.aspx
/REST/resource?_method=PUT /REST/resource.aspx?_method=PUT
/REST/resource?allVersions=true /REST/resource.aspx?allVersions=true