  We present a tetrad-affine approach to $f(\mathcal{Q})$ gravity coupled to
spinor fields of spin-1/2. After deriving the field equations, we derive the
conservation law of the spin density, showing that the latter ensures the
vanishing of the antisymmetric part of the Einstein-like equations, just as it
happens in theories with torsion and metricity. We then focus on Bianchi type-I
cosmological models proposing a general procedure to solve the corresponding
field equations and providing analytical solutions in the case of gravitational
Lagrangian functions of the kind $f(\mathcal{Q})=\alpha\mathcal{Q}^n$. At late
time such solutions are seen to isotropize and, depending on the value of the
exponent $n$, they can undergo an accelerated expansion of the spatial scale
factors.
