What is cosskill?
cosskill is an AI conversation simulator built for the talks that actually change things: asking for a raise, ending a relationship, delivering hard feedback, or holding a boundary with a parent. Instead of guessing how the other side will react, you rehearse the moment first.
How it works
- Pick a persona. Choose from 33 personas across operator, strategy, relationship, philosophy, psychology, and other styles—each with a distinct way of thinking and pushing back.
- Run a Mission. Goal-oriented scenarios drop you into a specific scene with a concrete objective. Live meters track how the other side responds as you talk.
- Practice until your words hold up. Say what you'd actually say, see where it lands, and refine before the real conversation happens.
Example missions
- Salary Negotiation Manager — ask for a 15% raise from a calm, budget-conscious hiring manager while meters track the room.
- Defensive Direct Report — deliver tough performance feedback to an engineer who interrupts and deflects.
- Angry Enterprise Customer — handle a churn threat from a customer whose production was down for four hours.
- Overbearing Parent — hold a boundary against guilt-tripping while tracking pressure, firmness, and harmony.
- Breakup Message Coach — write a clear, kind, final message on the first try.
Guides and extras
Alongside the simulator, cosskill offers 30 conversation guides covering breakups, salary negotiation, and more. It's free to start, requires no signup, and you can practice in seconds.

