The techniques described herein relate to methods and apparatus for firearm safety mechanisms, visual safety indicators, and related techniques. A firearm includes a handle comprising one or more buttons disposed at least partially within a surface of the handle, such that the one or more buttons can be in contact with an operator's hand when the operator grasps the handle; a safety mechanism in mechanical communication with the trigger. The safety mechanism comprises: a first position that blocks actuation of the trigger; and a second position that does not block actuation of the trigger; and at least one processor configured to: upon determining an input code matches a stored code, transmits a signal to the safety mechanism to change the safety mechanism from the first position to the second position so that the firearm can be fired by the operator.