Cook sausages in a large skillet over medium-high heat until brown on all sides, 2 to 3 minutes. Transfer to a plate.
Heat oil in the pan over medium-high heat. Add onion and apple and cook, stirring constantly, until beginning to brown, 1 to 2 minutes. Add cabbage, vinegar and salt and cook, stirring often, until just wilted, about 2 minutes. Add cider and caraway seeds; bring to a boil. Return the sausages to the pan, cover, reduce heat to a simmer and cook until the sausages are heated through and cabbage is tender, about 10 minutes.