Do not conflate with Tree nut allergy. Each restaurant page explains the evidence and what remains uncertain.
If you're considering Chick-fil-A with a peanut allergy, the chain's use of fully refined, heat-processed peanut oil is an important detail to review. Chick-fil-A says refining removes the peanut proteins and notes that the FDA does not classify highly refined peanut oil as a major allergen. That distinction may matter to your personal plan, but it doesn't answer every shared-preparation question.
For a Starbucks drink with a peanut allergy, review the complete standard build and every addition rather than relying on the drink name. Check the milk, syrup, sauce, cold foam, topping, powder, and seasonal garnish for the exact order. Starbucks also sells peanut-containing foods, but that food evidence doesn't answer what is in a customized drink.