  We establish the classification of minimal mass blow-up solutions of the
$L^2$ critical inhomogeneous nonlinear Schr\"odinger equation \[ i\partial_t u
+ \Delta u + |x|^{-b}|u|^{\frac{4-2b}{N}}u = 0, \] thereby extending the
celebrated result of Merle from the classic case $b=0$ to the case
$0<b<\min\{2,N\}$, in any dimension $N\ge1$.
