Now you can set/get: float, arrays (int and float) and string. The only special function is OP_get_string, it is special because return a pointer to the IDProperty data, so you can't change/resize/free the string. It's possible "fix" this with: 1) Return a "const char" 2) Return a duplicate string All this new function are not in use yet, but i make a simple test with the "move areas" operator (add a property of every type and then print the result in the other size) and work fine, more test are welcome. Other thing to check is the new OP_free_property function, because this properties are only local to the operator, i choice free all this in the "exit callback" of every operator (only move areas have property now), so comment about this are welcome too :) Also add some notes to the WM_api.h file.