  Recent work has proposed a method for imposing T-duality on the metric,
$B$-field, and dilaton of the classical effective action of string theory
without using Kaluza-Klein reduction. Specifically, the $D$-dimensional
effective action should be invariant under global $O(D,D)$ transformations,
provided that the partial derivatives along the $\beta$-parameters of the
non-geometrical elements of the $O(D,D)$ group become zero. In this paper, we
speculate that the global $\beta$-symmetry can be utilized to identify both
bulk and boundary couplings.
  We demonstrate that the Gibbons-Hawking term at the leading order of
$\alpha'$ is reproduced by this symmetry. Additionally, for closed spacetime
manifolds at order $\alpha'$, we show that the 20 independent geometrical
couplings at this order are fixed by this symmetry up to field redefinitions.
Specifically, we show that the invariance of the most general covariant and
gauge invariant bulk action at order $\alpha'$ under the most general covariant
deformed $\beta$-transformation at order $\alpha'$ fixes the action up to 13
parameters. These parameters reflect the field redefinitions freedom for the
closed spacetime manifolds. For particular values of these parameters, we
recover the effective action in the Metsaev-Tseytlin and in the Meissner
schemes.
