Prior to 9.3.6 version, Suppliers were not able to see PXs via the Actions Menu.  I believe in 9.3.6, you now have the ability to assign the PX to a given role for visibility as part of configuration.

The basic SDK does not allow you to do this.  We ended up using the Agile CoreServices…see a code snippet below:

CollaborationServiceLocator loc = new CollaborationServiceLocator();

Collaboration_BindingStub agileStub = null;

agileStub = (Collaboration_BindingStub) loc.getCollaboration(new URL(url));

 agileStub.setUsername(“genericID”);

agileStub.setPassword(“pwd”);

AddReviewersRequestType addApproversRequestType = new AddReviewersRequestType();

AgileAddReviewersRequestType agileAddApproversRequestType[] = new AgileAddReviewersRequestType[1];

agileAddApproversRequestType[0] = new AgileAddReviewersRequestType();

agileAddApproversRequestType[0].setClassIdentifier(classIdentifier);

agileAddApproversRequestType[0].setObjectNumber(changeNumber);

agileAddApproversRequestType[0].setStatusIdentifier(chgStatus);

AgileUserUserGroupIdentifierType users[] = new AgileUserUserGroupIdentifierType[1];

for (int i = 0; i < users.length; i++)

    users[i] = new AgileUserUserGroupIdentifierType();

 users[0].setClassIdentifier(“User”);

 users[0].setObjectIdentifier(userId);

 users[0].setJobFunction(jobFunction);

 agileAddApproversRequestType[0].setApprovers(users);

agileAddApproversRequestType[0].setUrgent(false);

agileAddApproversRequestType[0].setComment(comment);

addApproversRequestType.setAddReviewersRequest(agileAddApproversRequestType);

AddReviewersResponseType addApproversResponseType = agileStub.addReviewers(addApproversRequestType);

 Hope that helps!