Preheat the air fryer to 400°F. If using, lightly coat the air-fryer basket with cooking spray to prevent sticking.
In a bowl, combine the 8 ounces diced potatoes (cut into 1/2-inch cubes), 1 tablespoon olive oil, 1 teaspoon dried thyme, and 1/4 teaspoon salt; toss until the potatoes are evenly coated.
Arrange the seasoned potato cubes in a single layer in the air-fryer basket. If they won’t fit without crowding, cook in batches so they remain in a single layer.
Cook at 400°F for 8–10 minutes, shaking or tossing the basket once about halfway through the cooking time.
Test a potato with a fork for tenderness and light browning; if not done, cook an additional 1 minute and check again.
Remove the potatoes from the air fryer and serve.