The normal EDI validations done for (Inbound/Outbound)based on the Schema the WmEDI packages services will help.
For Inbound validation document level use the (wm.b2b.edi:convertToValues)and provide the following inputs EDIFFSchema=(X12document),validate=true,maxErrors=-1,
returnErrors=AsArray it will give output "errors"list,fomat this errors and display to users
For Outbound Validation document level use the
wm.b2b.edi:convertToString service and provide the inputs
ffSchema(X12 document) and if any errors it will give output “errorArray”,so format this errors and display to users.
And TN will do the EDI X12 Envelope Validation upon receiving the document,so basically you have to handle documentlevel validations using the inputs as i mentioned above.
HTH,
#edi#Integration-Server-and-ESB#webMethods