Preheat an air fryer to 375 degrees F (190 degrees C).
Combine asparagus, olive oil, balsamic vinegar, garlic powder, rosemary, sea salt, and black pepper in a large bowl. Toss to evenly coat the asparagus.
Air fry in a single layer (on the top rack if using an oven-style air fryer) until the asparagus spears begin to char, 7 to 10 minutes. Serve as-is with a lemon wedge for squeezing. Enjoy!