Preheat the air fryer to 390 degrees F (200 degrees C).
Place tomatoes and jalapeno skin-side down into the air fryer basket, along with red onion. Lightly spray vegetables with cooking spray to help the roasting process.
Air fry vegetables for 5 minutes. Open basket and add garlic cloves. Spray lightly with cooking spray and air fry for an additional 5 minutes.
Transfer vegetables to a cutting board and allow to cool for 10 minutes.
Remove skins from tomatoes and jalapeno, if desired; they should slip right off. Chop tomatoes, jalapeno, and onion into large chunks and add to the bowl of a food processor. Add garlic, cilantro, lime juice, and salt. Pulse several times until vegetables are finely chopped; do not over-process. Serve at room temperature or refrigerate to let flavors meld.