  We report superconductivity induced in films of the non-superconducting,
antiferromagnetic parent material FeTe by low temperature oxygen incorporation
in a reversible manner. X-ray absorption shows that oxygen doping changes the
nominal Fe valence state from 2+ in the non-superconducting state to mainly 3+
in the superconducting state. Thus superconductivity in O doped FeTe occurs in
a quite different charge and strain state than the more common
FeTe$_{1-x}$Se$_x$. This work also suggests a convenient path for conducting
doping experiments in-situ with many measurement techniques.
