Preheat the air fryer: Set to 400°F (200°C) for 3–5 minutes. A hot basket helps the veggies and shrimp cook quickly and get lightly charred edges.

Prep the produce: Thinly slice peppers and onion so they cook in the same time as the shrimp. Pat shrimp dry with paper towels for better browning.

Mix the seasoning: In a small bowl, combine chili powder, cumin, smoked paprika, garlic powder, onion powder, red pepper flakes (if using), salt, and black pepper.

Toss the veggies: In a large bowl, add peppers and onion with 1 tablespoon oil and half the seasoning. Toss to coat evenly.

Start the veggies: Add the seasoned peppers and onions to the air fryer basket in an even layer. Cook for 6–7 minutes, shaking the basket halfway.

Season the shrimp: While veggies cook, toss shrimp with remaining 1 tablespoon oil and the remaining seasoning. Add a pinch more salt if your shrimp are large.

Add shrimp to the basket: After the first 6–7 minutes, shake the veggies and make space. Add the shrimp on top in a single layer if possible.

Finish cooking: Air fry for 4–6 minutes, shaking once, until shrimp are pink, opaque, and just curled into a loose “C.” Do not overcook.

Add lime and cilantro: Zest half the lime over the hot shrimp and veggies, then squeeze in 1–2 teaspoons juice. Sprinkle with chopped cilantro.

Warm tortillas: Wrap tortillas in a damp paper towel and microwave 20–30 seconds, or place them in the air fryer for 30–60 seconds at 350°F.

Serve: Build fajitas with shrimp, peppers, and onions. Add your favorite toppings. Taste and adjust with a squeeze of lime and a pinch of salt.