Hi, there's CPython ticket (actually two of them) about providing a C level API for the decimal implementation in Py3.3+, which is based on a separate C library (libmpdec). This would allow unboxing Decimal objects and working directly with the underlying libmpdec values. "access to cdecimal / libmpdec API" http://bugs.python.org/issue22194 "Add capsule API to _decimal" http://bugs.python.org/issue15237 Direct access to libmpdec (which is linked into _cdecimal on some platforms) requires exporting the symbols. If anyone has experience with that on less common or less straight forward platforms, a comment in the first ticket would certainly be appreciated. Stefan