Dear Stephane, 

you can use a post like this (tested with postman):

First Login: http://docuware/DocuWare/Platform/Account/Logon?UserName=xxx&Password=xx...

Then a POST command (with curl - postman or other tools)

http://docuware/DocuWare/Platform/FileCabinets/c664c5fd-6ae4-48f6-bd2e-9ac81628089a/Documents/57/Fields/

With xml (or Json) as body, which contains index fields:

<?xml version="1.0" encoding="utf-8"?>

<?xml-stylesheet type="text/xsl" href="/DocuWare/Platform/Content/standard.xslt"?>

<DocumentIndexFields xmlns:s="http://dev.docuware.com/schema/public/services" xmlns="http://dev.docuware.com/schema/public/services/platform">

    <Field FieldName="NR_STATUT" FieldLabel="Nr statut">

        <String>02</String>

    </Field>

</DocumentIndexFields>

 

 

Kind Regards