For each of the CRUD request there's a table with supported entities. Is there any way to obtain such info from SDK/WebAPI per entity type?
Probably some metadata properties or separate requests to check?
Maybe this documentation should help you.
To verify if a message and entity combination supports execution of plug-ins using a database query, you can use the following Web API query:
{{webapiurl}}sdkmessages?$select=name
&$filter=isprivate eq false
and (name ne 'SetStateDynamicEntity'
and name ne 'RemoveRelated'
and name ne 'SetRelated' and
name ne 'Execute')
and sdkmessageid_sdkmessagefilter/any(s:s/iscustomprocessingstepallowed eq true
and s/isvisible eq true)
&$expand=sdkmessageid_sdkmessagefilter($select=primaryobjecttypecode;
$filter=iscustomprocessingstepallowed eq true and isvisible eq true)
&$orderby=name
Fetchxml version:
<fetch>
<entity name='sdkmessage' >
<attribute name='name' />
<link-entity name='sdkmessagefilter' alias='filter' to='sdkmessageid' from='sdkmessageid' link-type='inner' >
<filter type='and' >
<condition attribute='iscustomprocessingstepallowed' operator='eq' value='1' />
<condition attribute='isvisible' operator='eq' value='1' />
</filter>
<attribute name='primaryobjecttypecode' />
</link-entity>
<filter>
<condition attribute='isprivate' operator='eq' value='0' />
<condition attribute='name' operator='not-in' >
<value>SetStateDynamicEntity</value>
<value>RemoveRelated</value>
<value>SetRelated</value>
<value>Execute</value>
</condition>
</filter>
<order attribute='name' />
</entity>
</fetch>