Slice the cucumbers and onion approximately ¼ inch thick.
Pack the vegetables into two clean pint jars.
Make the brine by combining the vinegar, water, sugar, salt, and spices in a saucepan over medium heat. Let simmer, while stirring, until the sugar and salt are dissolved.
Pour the brine over the vegetables in the jars.
Put on the lids, let the jars cool, then put in the refrigerator. Wait 24 hours before eating. These should last about a month in the refrigerator.