Bring figs, sugar, the seeds from 1/2 vanilla bean and salt to a boil in a saucepan over medium heat and stir until the sugar melts.
Continue cooking, stirring occasionally, until a drop of the mixture sets on a chilled plate, about 20 minutes.
Remove from the heat. Stir in lemon juice and ruby port.
Fill sterilized jars, leaving a 1/2-inch headspace, then seal and process for 15 minutes.
Jam can also be stored in sterilized jars in the refrigerator for up to 6 months.